05-EDP-358
ELECTRICAL SWITCHING APPARATUS, AND HOUSING AND INTEGRAL
POLE SHAFT BEARING ASSEMBLY THEREFOR

BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates generally to electrical switching apparatus and, more
particularly, to an electrical switching apparatus, such as a circuit breaker having a
housing and a pole shaft bearing assembly. The invention also relates to housings for
circuit breakers. The invention further relates to pole shaft bearing assemblies for circuit
breakers.
Background Information
Electrical switching apparatus, such as circuit breakers, provide protection
for electrical systems from electrical fault conditions such as, for example, current
overloads, short circuits, abnormal voltage and other fault conditions. Typically, circuit
breakers include an operating mechanism which opens electrical contact assemblies to
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interrupt the flow of current through the conductors of an electrical system in response to
such fault conditions.
Many low-voltage circuit breakers, for example, employ a molded housing
having two parts, a first half or front part (e.g., a molded cover), and a second half or rear
part (e.g., a molded base). The operating mechanism for such circuit breakers is often
mounted to the front part of the housing, and typically includes an operating handle
and/or button(s) which, at one end, is (are) accessible from the exterior of the molded
housing and, at the other end, is (are) coupled to a pivotable pole shaft. Electrical contact
assemblies, which are also disposed within the molded housing, generally comprise a
conductor assembly including a movable contact assembly having a plurality of movable
contacts, and a stationary contact assembly having a plurality of corresponding stationary
contacts. The movable contact assembly is electrically connected to a generally rigid
conductor of the conductor assembly by flexible conductors, commonly referred to as
shunts. The movable contact assembly includes a plurality of movable contact arms or
fingers, each carrying one of the movable contacts and being pivotably coupled to a
contact arm carrier. The contact arm carrier is pivoted by a protrusion or arm on the pole
shaft of the circuit breaker operating mechanism to move the movable contacts into and
out of electrical contact with the corresponding stationary contacts of the stationary
contact assembly. The contact arm carrier includes a contact spring assembly structured
to bias the fingers of the movable contact assembly against the stationary contacts of the
stationary contact assembly in order to provide and maintain contact pressure when the
circuit breaker is closed, and to accommodate wear.
Each of the components of the circuit breaker, including the two parts or
halves (e.g., the molded cover and the molded base) of the circuit breaker housing, is
subject to dimensional variation during manufacturing. Specifically, molded
components, such as the molded cover and molded base, have a parting line which is
created as part of the molding process, and which results in one portion (e.g., the exterior
side) varying in dimension with respect to another portion (e.g., the interior side) of the
same component. Such variations are also cumulative when the parts are assembled. For
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example, as previously noted, the operating mechanism of known low-voltage circuit
breakers is mounted to the front part of the housing, which in turn is coupled to the rear
part of the housing to which the stationary contact assembly is coupled. Thus, the parts
are connected or "stacked" in series. Variations among the parts within the series add up,
resulting in an undesirable reduction of the accuracy of the relationship (i.e., alignment)
between parts across the stack.
The two separate half structures of the circuit breaker molded housing are
particularly susceptible to misalignment. Specifically, variations across the parting line
(the line designating the two halves of the mold used to make the component) as well as
variations across the mating line or lines between components in the stack, result in
misalignment between, for example, the stationary contact assembly and the pole shaft of
the operating mechanism, thus inhibiting circuit breaker performance. The accuracy with
which the components of the circuit breaker are mounted with respect to one another
significantly affects the kinematics of the circuit breaker, and the predictable and thus
repeatable mechanical, electrical and thermal performance of the circuit breaker.
Accordingly, there is a need for a cost-effective circuit breaker design structured to
reduce the aggregate dimensional variation among components of the circuit breaker.
It is known that the effects of dimensional variations between circuit
breaker components such as, for example, between the stationary contact assembly and
the operating mechanism and pole shaft, can, in large part, be minimized by reducing
manufacturing tolerances. However, this approach would significantly increase
manufacturing cost.
There is, therefore, room for improvement electrical switching apparatus,
such as low-voltage circuit breakers, and in housings for circuit breakers and in mounting
assemblies for circuit breaker components.
SUMMARY OF THE INVENTION
These needs and others are met by embodiments of the invention, which
are directed to a molded housing for an electrical switching apparatus, such as a low-
voltage circuit breaker, having an integral pole shaft bearing assembly structured to
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minimize the accumulation of manufacturing dimensional variations and undesirable
effects associated with the same.
As one aspect of the invention, a bearing assembly is provided for an
electrical switching apparatus including a housing having at least one parting line and an
exterior side, a stationary contact assembly disposed on one side of the parting line, a
movable contact assembly, and an operating mechanism. The operating mechanism
includes a pole shaft for moving the movable contact assembly into and out of electrical
contact with the stationary contact assembly. The bearing assembly comprises: a number
of primary bearings structured to pivotably support the pole shaft of the operating
mechanism on the same side of the parting line as the stationary contact assembly; an
integral bearing section structured to pivotably couple the pole shaft of the operating
mechanism to the housing of the electrical switching apparatus; and at least one bearing
cover member including a bearing surface and a fastening portion structured to be
coupled to the exterior side of the housing of the electrical switching apparatus. When
the fastening portion of the bearing cover member is coupled to the exterior side of the
housing, the pole shaft of the operating mechanism is pivotably disposed between the
integral bearing section and the bearing surface of the bearing cover member on the
exterior side of the housing.
The pole shaft of the operating mechanism may be generally cylindrical in
shape and the integral bearing section may comprise a plurality of molded portions
structured to be molded on the exterior side of the housing of the electrical switching
apparatus in order to receive the generally cylindrical pole shaft. The at least one bearing
cover member may be a plurality of bearing cover members, wherein the integral bearing
section and the bearing cover members combine to form a plurality of secondary pole
shaft bearings each having a first part and a second part, and wherein the molded portions
of the integral bearing section comprise the first part and the bearing surface of each of
the bearing cover members comprises the second part.
As another aspect of the invention, a housing is provided for an electrical
switching apparatus including a stationary contact assembly, a movable contact assembly,
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and an operating mechanism including a pole shaft for moving the movable contact
assembly into and out of electrical contact with the stationary contact assembly. The
housing comprises: a molded cover having a parting line and an exterior side; a molded
base disposed generally opposite from and coupled to the molded cover, the molded base
including a parting line and an exterior side, the molded base being structured to receive
the stationary contact assembly of the electrical switching apparatus on one side of the
parting line of the molded base; and a bearing assembly comprising: a number of primary
bearings structured to pivotably support the pole shaft of the operating mechanism of the
electrical switching apparatus on the same side of the parting line of the base member as
the stationary contact assembly of the electrical switching apparatus, an integral bearing
section, and at least one bearing cover member including a bearing surface and a
fastening portion, wherein the fastening portion of the at least one bearing cover member
couples the at least one bearing cover member to one of the molded cover and the molded
base, in order that the pole shaft of the operating mechanism is pivotably disposed
between the integral bearing section and the bearing surface of the at least one bearing
cover member on the exterior side of the one of the molded cover and the molded base.
The molded cover and the molded base may each further comprise an
interior side and a number of substantially vertical walls extending outwardly from the
interior side, wherein each of the primary bearings comprises a molded extension of one
of the substantially vertical walls of the molded base that couples to a corresponding
bearing cover member of the integral bearing section proximate one of the molded
portions of the integral bearing section, in order to support the pole shaft of the operating
mechanism. The bearing assembly may further comprise a plurality of fasteners wherein
the bearing cover members comprise a first molded cover member, a second molded
cover member, a third molded cover member, and a fourth molded cover member and
wherein at least one of the first molded cover member, the second molded cover member,
the third molded cover member, and the fourth molded cover member is coupled to the
molded extension of a corresponding one of the substantially vertical walls by at least one
of the fasteners. The molded cover and the molded base may be joined at a mating line
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wherein the pole shaft of the electrical switching apparatus operating mechanism is
substantially disposed on the exterior side of one of the molded cover and the molded
base of the housing and is substantially pivotably coupled to and supported by the
primary bearings of the other one of the molded cover and molded base of the housing,
thereby being substantially independent of dimensional and tolerance variations across
the mating line.
As another aspect of the invention, an electrical switching apparatus
comprises: a stationary contact assembly having a plurality of stationary electrical
contacts; a movable contact assembly having a plurality of movable contact arms and a
plurality of movable electrical contacts coupled to the movable contact arms; an
operating mechanism including a pole shaft for moving the movable contact arms and the
movable electrical contacts coupled thereto into and out of electrical contact with the
stationary electrical contacts of the stationary contact assembly; and a housing
comprising: a molded cover having a parting line and an exterior side, a molded base
disposed generally opposite from and coupled to the molded cover, and including a
parting line, the stationary contact assembly being disposed on one side of the parting
line of the molded base, and a bearing assembly comprising: a number of primary
bearings pivotably supporting the pole shaft of the operating mechanism of the electrical
switching apparatus on the same side of the parting line of the molded base as the
stationary contact assembly of the electrical switching apparatus, an integral bearing
section, and at least one bearing cover member including a bearing surface and a
fastening portion, wherein the fastening portion of the at least one bearing cover member
couples the at least one bearing cover member to one of the molded cover and the molded
base, in order that the pole shaft of the operating mechanism is pivotably disposed
between the integral bearing section and the bearing surface of the at least one bearing
cover member at or about the exterior side of the one of the molded cover and the molded
base.
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BRIEF DESCRIPTION OF THE DRAWINGS
A full understanding of the invention can be gained from the following
description of the preferred embodiments when read in conjunction with the
accompanying drawings in which:
Figure 1 is an exploded isometric view of a low-voltage circuit breaker
and integral pole shaft bearing assembly in accordance with an embodiment of the
invention;
Figure 2 is an exploded isometric view of the conductor assembly for the
low-voltage circuit breaker of Figure 1;
Figure 3 is a side elevational view of a portion of the conductor assembly
of Figure 2;
Figure 4 is a top plan view of the conductor assembly of Figure 2,
including a self-contained contact spring assembly;
Figure 5 is an exploded isometric view of the self-contained contact spring
assembly of Figure 4;
Figure 6A is an assembled top isometric view of the self-contained contact
spring assembly of Figure 5;
Figure 6B is an assembled bottom isometric view of the self-contained
contact spring assembly of Figure 5;
Figure 7 is an isometric view of one component of the independent carrier
assembly of Figure 1;
Figure 8 is an isometric view of another component of the independent
carrier assembly of Figure 1;
Figure 9 is a partially assembled isometric view of the low-voltage circuit
breaker and integral pole shaft bearing assembly therefor, of Figure 1;
Figure 10 is an assembled side elevational cross-sectional view of the low-
voltage circuit breaker and integral pole shaft bearing assembly therefor, of Figure 1;
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Figure 11 is an isometric view of the underside of the molded cover of the
low-voltage circuit breaker and a portion of the integral pole shaft bearing assembly
therefor, of Figure 1; and
Figure 12 is an isometric view of the top side of the molded cover of the
low-voltage circuit breaker and a portion of the integral pole shaft bearing assembly
therefor, of Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of illustration, embodiments of the invention will be
described as applied to the pole shaft bearing assembly of a low-voltage circuit breaker
although it will become apparent that they could also be applied to minimize dimensional
variations between a variety of different components of any known or suitable electrical
switching apparatus (e.g., without limitation, circuit switching devices and circuit
interrupters such as circuit breakers, network protectors, contactors, motor starters, motor
controllers and other load controllers).
Directional phrases used herein, such as, for example, left, right,
clockwise, counterclockwise and derivatives thereof, relate to the orientation of the
elements shown in the drawings and are not limiting upon the claims unless expressly
recited therein.
As employed herein, the term "parting line" refers to the line which is
created between sections of the mold which is used as part of the molding process for
producing a molded component such as, for example and without limitation, the molded
cover and molded base of the housing of the circuit breaker shown and described herein.
Dimensional and tolerance variations occur across the parting line, such that one portion
or section of the molded component on one side of the parting line is not in the desired
precise orientation with respect to another portion or section on the other side of the
parting line. For example and without limitation, the example parting lines discussed
herein are defined between the respective interior surfaces or sides and the exterior
surfaces or sides of the molded cover and molded base of the circuit breaker housing.
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As employed herein, the term "mating line" refers to the junction or
interface between two adjacent, separate components such as, for example and without
limitation, the mating line defined by the junction of the molded cover of the example
circuit breaker housing with the molded base of the circuit breaker housing.
As employed herein, the statement that two or more parts are "coupled"
together shall mean that the parts are joined together either directly or joined through one
or more intermediate parts.
As employed herein, the term "fastener" refers to any suitable connecting
or tightening mechanism expressly including, but not limited to, screws, bolts and the
combinations of bolts and nuts (e.g., without limitation, lock nuts) and bolts, washers and
nuts.
As employed herein, the term "number" shall mean one or an integer
greater than one (i.e., a plurality).
Figure 1 shows a low-voltage circuit breaker 2 including a housing 3
which encloses a conductor assembly 50 having a movable contact assembly 100 with
flexible conductive elements 200 (one flexible element 200 is shown in hidden line
drawing in simplified form in Figure 1), in accordance with embodiments of the
invention. The housing 3 includes a first half or front part 4 (e.g., a molded cover) and a
second half or back part 5 (e.g., a molded base), with the conductor assembly 50 being
disposed therebetween. The low-voltage circuit breaker 2 further includes first and
second conductors such as the example line and load conductors 6,8 partially shown in
phantom line drawing in simplified form in Figure 3.
As shown in Figures 2 and 3, the conductor assembly 50 includes a load
conductor 52, a movable contact assembly 100, and a plurality of the flexible conductive
elements 200 electrically connecting the load conductor 52 and the movable contact
assembly 100. The movable contact assembly 100 includes a plurality of movable
contact arms 110. Each of the movable contact arms 110 has a first end 112 and a second
end 114. A movable electrical contact 130 is coupled to each movable contact arm 110 at
or about the first end 112 thereof, and is structured to move into and out of electrical
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contact with a corresponding stationary electrical contact 12 (Figure 3) of the low-voltage
circuit breaker 2 (Figure 1). Specifically, as shown in Figure 3, the first electrical
conductor or line conductor 6 of the circuit breaker 2 (Figure 1) includes a stationary
contact assembly 10 (shown in phantom line drawing in simplified form) having a
plurality of stationary electrical contacts 12 (one stationary electrical contact 12 is shown
in Figure 3).
When the conductor assembly 50 is assembled within the circuit breaker
housing 3 (Figure 1) the load conductor 52 is in electrical contact with the second
electrical conductor or load conductor 8 of the circuit breaker 2 and the movable
electrical contact 130 is movable into (Figure 3) and out of (not shown) electrical contact
with the corresponding stationary electrical contact 12 of the stationary contact assembly
10. It will be appreciated that, for simplicity of illustration, only one conductor assembly
50 is shown in the figures. Typically, however, the low-voltage circuit breaker 2, shown
in Figure 1, which is a three-pole circuit breaker 2, would include three such conductor
assemblies 50, one for each of the poles of the circuit breaker 2. It will further be
appreciated that the conductor assembly 50 could be employed with any known or
suitable electrical switching apparatus having any number of poles other than the three-
pole low-voltage circuit breaker 2 shown and described in connection with Figure 1.
Referring to Figures 2 and 3, each of the flexible conductive elements 200
which electrically connect the load conductor 52 of the conductor assembly 50 to the
movable contact assembly 100, includes a first end 202 structured to be electrically
connected to the load conductor 52, a second end 204 structured to be electrically
connected to a corresponding one of the movable contact arms 110 of the movable
contact assembly 100, and a plurality of bends 206,208 between the first end 202 and the
second end 204. As best shown in Figure 3, a first one of the bends 206 is in a first
direction and at least a second one of the bends 208 is in a second direction which is
generally opposite the first direction of the first bend 206. More specifically, the example
flexible conductive element 200 is a shunt comprising layered conductive ribbon 230
(shown exaggerated in Figures 2 and 3 for ease of illustration), and includes two bends
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206,208, a first bend 206 in the first direction, and a second bend 208 in the second
direction in order that the shunt 200 is generally S-shaped. Accordingly, the shunt 200
includes a first portion 210 disposed between the first end 202 and the first bend 206, a
second portion 212 disposed between first bend 206 and second bend 208, and a third
portion 214 disposed between second bend 208 and the second end 204 of the shunt 200.
The generally S-shape configuration of the shunt 200 permits it to have a relatively low
profile in a vertical direction, thus minimizing the amount of space required for the
conductor assembly 50 within the circuit breaker housing 2 (Figure 1).
An axis 220 extends between the first end 202 of the shunt 200 and the
second end 204 of the shunt 200. The first portion 210 of the shunt 200 forms a first
angle 222 with respect to axis 220 on one side of the axis, and the third portion 214 of the
shunt 200 forms a second angle 224 with respect to the axis 220, on the opposite side of
the axis 220. Preferably the first and second angles 222,224 of the first and third portions
210,214 of shunt 200, are different. For example, the first angle 222 of the shunt 200 of
Figure 3 is greater than second angle 224. By way of a non-limiting example, the first
angle 222 of the example shunt 200 is between about 26 degrees and about 36 degrees
with respect to axis 220, and the second angle 224 is between about 11 degrees and about
22 degrees. It will, however, be appreciated that any known or suitable shunt
configuration could be employed in accordance with embodiments of the invention to
accommodate the compound motion of the conductor assembly 50 while minimizing
areas of stress concentration in the shunts 200 and providing a compact shunt design. It
will also be appreciated that while the shunt 200 is contemplated as being made from
wound layered conductive ribbon 230 which is made of copper, that any known or
suitable electrically conductive material could alternatively be employed without
departing from the scope of the invention. Likewise, while the example shunt 200 has
about 58 layers of conductive ribbon 230, a width of about 0.35 inches, a length of about
2.2 inches (measured from the center of the first end 202 of shunt 200 to the center of the
second end 204 thereof), an overall thickness of about .187 inches, and a ribbon layer
thickness of about .003 inches, it will be appreciated that one or more of these
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dimensions could be changed to any known or suitable value as necessary for the
particular application in which the shunt 200 will be used.
Continuing to refer to Figures 2 and 3, the load conductor 52 of the
conductor assembly 50 comprises a solid conductor 52 having a first portion 53 and a
second portion 55 generally opposite the first portion 53. The first portion 53 includes a
first aperture which generally comprises a single elongated recess 54 (best shown in
Figure 2). The single elongated recess 54 receives the first ends 202 of all of the shunts
200. The second ends 204 of the shunts 200 are received in corresponding second
apertures 116 in the second ends 114 of each of the movable contact arms 110 (six shunts
200 are shown in Figure 2). More specifically, the first end 202 of each shunt 200
comprises a first generally round head 226 and the second end 204 of the shunt 200
comprises a second generally round head 228. The single elongated recess 54 of the load
conductor 52 and the second aperture 116 of the corresponding movable contact arms
110 each comprise an interior arcuate portion 56,118 and a neck portion 58,120,
respectively, as shown. The first generally round head 226 of the first end 202 of shunt
200 is disposed within the interior arcuate portion 56 of the first aperture or single
elongated recess 54 of the load conductor 52, as shown, and the neck portion 58 of the
first aperture 54 is compressed against shunt 200 in the direction indicated by arrows 201
of Figure 3 in order to retain the first end 202 of the shunt 200 within the first aperture
54. Similarly, the second generally round head 228 is disposed within the second
aperture 116 of the corresponding movable contact arm 110, and the second end 204 of
the shunt 200 is retained within the interior arcuate portion 118 of the second aperture
116. Such retention can be provided by the neck portion 120 of the second aperture 116
being compressed against the shunt 200 in the direction generally indicated by arrows
203 of Figure 3, but may further or alternatively be provided by a pin 234 being inserted
through the round head 228 (discussed hereinbelow) and then swaged or peened to
expand the layers of conductive ribbon 230 of the second end 204 radially outward
against the interior arcuate portion 118 of the second aperture 116.
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For each of the example shunts 200, the first and second generally rounds
heads 226,228 of the first and second ends 202,204 further include first and second pins
232,234 disposed through the center of the heads 226,228 within the first and second
apertures 54,116, respectively. More specifically, the layers of conductive ribbon 230 of
the shunt 200 wrap around the first and second pins 232,234 within the first and second
apertures 54,116, respectively, of the load conductor 52 and the corresponding movable
contact arm 110, respectively, as shown in Figure 3.
In Figure 2, the first pin 232 is shown before being inserted through the
center of the first generally round head 226 of each of the shunts 200 within the interior
arcuate portion 56 of the single elongated recess 54 of the load conductor 52.
Accordingly, it will be appreciated that the first and second ends 202,204 of the shunts
are secured within the first and second apertures 54,116, respectively, of the load
conductor 52 and the corresponding movable contact arms 210. This may be
accomplished by, for example and without limitation, swaging or crimping a portion
(e.g., neck portion 58) of the load conductor 52 adjacent the first aperture 54, and a
portion (e.g., neck portion 120) of the corresponding movable contact arm 110 adjacent
the second aperture 116 against the first and second ends 202,204 of the shunts 200,
respectively, or by any other known or suitable fastening process or mechanism, such as,
for example, a rivet 232,234 (e.g., a staked or suitably deformed pin), solder, brazing, or
any suitable combination thereof.
As best shown in Figure 2, the movable contact assembly 100 may further
include a plurality of spacers 150 structured to separate the movable contact arms 110 of
the assembly 100 from one another. Specifically, each of the spacers 150 includes a first
portion 152, a connection portion 154, and a second portion 156 spaced opposite from the
first portion 152, as shown. Each of the movable contact arms 110 of the movable
contact assembly 100 is disposed between the first and second portions 152,156 of one of
the spacers 150, thereby separating one movable contact arm 110 from at least one other
movable contact arm 110 of the movable contact assembly 100. The spacers 150 may be
made from any known or suitable material, such as, for example and without limitation,
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vulcanized fiber material, commonly referred to as fish paper. It will be appreciated that
the spacers 150 may, but need not necessarily, also serve to electrically and/or thermally
insulate the movable contact arms 110 of the assembly 100 from one another.
In addition to the aforementioned flexible conductive members 200,
Figure 2 also shows a contact spring assembly 300 for the movable contact assembly 100
of conductor assembly 50. The movable contact assembly 100, previously discussed,
further includes opposing first and second carrier members 102,104 which secure the
movable contact arms 110 therebetween, thus comprising a carrier assembly 101. The
contact spring assembly 300 is coupled to at least one of the first and second carrier
members 102,104, and is disposed between the first and second carrier members 102,104
proximate the second ends 114 of the movable contact arms 110.
Referring to Figures 2, 4, 5, 6A, and 6B, the contact spring assembly 300
includes a first contact spring housing member 302 and a second contact spring housing
member 304 coupled to the first contact spring housing member 302 and disposed
opposite therefrom. A spring guide 306 is coupled to at least one of the first and second
contact spring housing members 302,304, and is disposed therebetween. The spring
guide 306 includes a plurality of spring holes 308 each structured to receive a
corresponding spring 312. Specifically, each spring 312 has a first end 314, which is
received by a corresponding one of the spring holes 308 of spring guide 306, and a
second end 316, which is coupled to a corresponding slider 310 (best shown in Figures 2
and 5). Each of the springs 312 and sliders 310 coupled thereto is structured to
individually bias a corresponding one of the movable contact arms 110 (Figures 1-4) of
the movable contact assembly 100 (Figures 1-4) and the movable electrical contact 130
(Figures 1-3) coupled thereto towards engagement with a corresponding one of the
stationary electrical contacts 12 (Figure 3) of the stationary contact assembly 10 (Figure
3).
The example first and second contact spring housing members 302,304 are
substantially identical. Thus, the number of components which must be manufactured for
the contact spring assembly 300 is reduced, thereby reducing the associated
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manufacturing costs. Additionally, the substantially identical first and second contact
spring housing members 302,304 enable the contact spring assembly 300 to be secured
together without requiring the use of conventional mechanical fasteners (e.g., without
limitation, screws; rivets; bolts and nuts), as will be discussed in greater detail herein
below.
As shown in Figures 2 and 5, the example contact spring assembly 300
includes six springs 312 which are received in six corresponding spring thru holes 308 of
the spring guide 306. The thru holes 308 (best shown in Figure 5) extend completely
through the spring guide 306, in order to receive the first ends 314 of the springs 312. As
previously discussed, the second ends 316 of the springs 312 are coupled to individual
sliders 310. Each slider 310 includes a first end 326 coupled to the second end 316 of a
corresponding one of the springs 312, and a second end 328 comprising a cam element
such as the rollers 330, best shown in Figures 2 and 4. Each of the cam elements 330
(Figures 2 and 4) is structured to engage and move a corresponding one of the movable
contact arms 110 of the movable contact assembly 100.
Referring to Figures 5, 6A and 6B, the first and second contact spring
housing members 302,304 of the contact spring assembly 300 each include a plurality of
elongated guide slots 332,334 for receiving first and second protrusions 342,346 on the
first and second sides 340,344 of each slider 310. Specifically, the first and second
protrusions 342,346 engage an opposing pair of the elongated guide slots 332,334 of the
first and second spring housing members 302,304, respectively, in order to guide the
slider 310 and cam element 330 (Figures 2 and 4) towards engagement with the
corresponding movable contact arm 110 (Figures 2 and 4). For example, in Figure 4, five
of the cam elements 330 are extended and engaging the second ends 114 of
corresponding movable contact arms 110 of the movable contact assembly 100. The
sixth cam element 330 is retracted, as indicated by the position of the first protrusion 342
of slider 310 within the first guide slot 332 of the first contact spring housing member
302. Accordingly, it will be appreciated that the cam elements 330 (Figures 2 and 4) of
the contact spring assembly 300 in accordance with embodiments of the invention
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individually engage and bias a corresponding movable contact arm 110 (Figures 2 and 4)
independent from the remainder of the cam elements 330 (Figures 2 and 4) of the contact
spring assembly 300. It will be appreciated that the cam elements 330 can comprise any
known or suitable bearing element, such as the small wheel 330 shown in Figure 2, which
is pivotably disposed within a recess 348 at the second end 328 of slider 310.
As previously noted, the contact spring assembly 300 is secured together
and to the carrier assembly 101 (Figure 2), without requiring the use of separate
mechanical fasteners. More specifically, as best shown in Figures 5, 6A and 6B, the first
and second contact spring housing members 302,304 each include at least one protrusion
366,368 and at least one aperture 374,376, wherein the first and second contact spring
housing members 302,304 are positioned in order that the protrusion 366,368 of one of
the first and second contact spring carrier members 302,304 engages the aperture 374,376
of the other of the first and second contact spring carrier member 302,304, respectively,
thereby securing the contact spring assembly 300 together. More specifically, the first
and second contact spring housing members 302,304 each include a first end 350,352 and
a second end 354,356, respectively. The first end 350,352 includes a folded tab 362,364
including the protrusion 366,368, and an unfolded tab 370,372 having the aperture
374,376. The relationship between the first and second contact spring housing members
302,304 which, as previously discussed, are substantially identical, can best be
appreciated with reference to the front and back isometric views of the contact spring
assembly 300 shown in Figures 6A and 6B, respectively. Specifically, protrusion 366 of
the folded tab 362 of the first end 350 of first contact spring housing member 302
engages the aperture 376 of the unfolded tab 372 of the first end 352 of second contact
spring housing member 304, and protrusion 368 of the folded tab 364 of the first end 352
of second contact spring housing member 304 engages the aperture 374 of the unfolded
tab 370 of the first end 350 of first contact spring housing member 302.
The second ends 354,356 of the first and second contact spring housing
members 302,304 each comprise a pair of lateral protrusions 378,380 which, as best
shown in Figures 2 and 4, are structured to engage corresponding slots 126,128 in the
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first and second carrier members 102,104 of the carrier assembly 101 of movable contact
assembly 100. More specifically, the pair of lateral protrusions 378,380 of the second
end 354,356 of one of the first and second contact spring housing members 302,304
engages corresponding slots 126,128 in the first and second carrier members 102,104,
respectively, of the carrier assembly 101, thereby securely coupling the contact spring
assembly 300 to the movable contact assembly 100, without the use of separate
mechanical fasteners.
The first and second contact spring housing members 302,304 also include
an intermediate portion 358,360 having a pair of recesses 382,384, respectively. The
recesses 382,384 are engaged by corresponding first and second pairs of protrusions
388,392 on the first and second sides 386,390, respectively, of the spring guide 306.
As shown in Figures 1, 2, and 4, the movable contact arms 110 of the
movable contact assembly 100 have an axis of a rotation 124. The axis of a rotation 124
extends generally perpendicularly with respect to the first and second carrier members
102,104 of the carrier assembly 101. More specifically, the movable contact arms 110
pivot clockwise and counterclockwise (from the perspective of Figures 1 and 2) about a
pivot pin 132, which extends through a corresponding aperture 134 (Figure 2) in each of
the movable contact arms 110. The contact spring assembly 300 is coupled to the
movable contact assembly 100, in the manner previously discussed, at a location which is
above and behind the axis of rotation 124. This location, which is proximate the second
ends 114 of the movable contact arms 110 of the movable contact assembly 100, provides
the springs 312 of the contact spring assembly 300 with a mechanical advantage by
placing them at a location (e.g., above and behind) which facilitates pivotal movement of
the movable contact arms 110 about the aforementioned axis of a rotation 124. More
specifically, the second end 114 of each movable contact arm 110 includes a cam profile
122 (Figures 2-4). In operation, the roller cam element 330 (Figures 2-4) of each slider
310 (Figures 2, 4, 5, 6A and 6B) of the contact spring assembly 300 (Figures 1, 2,4, 5,
6A and 6B) engages the cam profile 122 of a corresponding one of the movable contact
arms 110. In turn, as shown in Figure 3, the roller cam element 330 (shown in phantom
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line drawing in simplified form in Figure 3) rolls along the cam profile 122 in the
direction generally indicated by arrow 136 of Figure 3 as it biases the second end 114 of
the movable contact arm 110 in the direction generally indicated by arrow 138 of Figure
3, causing the movable contact arm 110 to pivot clockwise (from the perspective of
Figure 3) about axis of rotation 124 as generally indicated by arrow 140 of Figure 3. In
this manner, movable electrical contact 130 of the movable contact arm 110 is pivoted
toward electrical contact with stationary electrical contact 12 of the stationary contact
assembly 10. It will be appreciated that the cam profile 122 could have any known or
suitable shape in order to provide the desired movable contact arm 110 motion.
The example stationary contact assembly 10, which is shown in phantom
line drawing in simplified form in Figure 3, includes a first contact portion 14 which is
engaged by movable electrical contact 130 on movable contact arm 110, as shown. It
will, however, be appreciated that the stationary contact assembly 10 could have any
known or suitable alternative configuration. For example and without limitation, it could
further include a second contact portion 16, as shown in phantom line drawing in
simplified form in Figure 3. It will also be appreciated that the first end 112 of the
movable contact arm 110 could include, for example, a toe portion 106 and a heel portion
108, with the movable electrical contact 130 being mounted on the heel portion 108, as
shown. The movable electrical contact 130 at or about the heel portion 108 is movable
into and out of electrical contact with the stationary electrical contact 12 of first contact
portion 14 of the stationary contact assembly 10, and the toe portion 106 is movable into
(not shown) and out of (as shown) electrical contact with the second contact portion 16 of
the stationary contact assembly 10. This movable and stationary electrical contact
interaction is commonly referred to in the art as a "heel-toe" contact configuration, and is
generally well known. Thus, the contact spring assembly 300 facilitates movement of the
movable contact assembly 100 which is controlled by the circuit breaker operating
mechanism (shown in simplified form in Figure 1), in any suitable well known manner.
Referring to Figures 1 and 7-11, a pivot assembly 400 for the carrier
assemblies 101 (Figures 1 and 9) of the low-voltage circuit breaker 2 (Figures 1, 9 and
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10) is shown. The pivot assembly 400 comprises a plurality of pivot members 402,404
which are separate independent components from the circuit breaker housing 3 (Figures 1
and 9-11). The pivot member 402,404 are structured to be clam-shelled between the
molded cover 4 (Figures 1 and 9-10) and the molded base 5 (Figures 1, 9 and 10) of the
circuit breaker housing 3, in order to improve the accuracy with which the carrier
assembly 101 and components thereof (e.g., without limitation, movable contact
assembly 100) are mounted within the circuit breaker 2.
As best shown in Figure 9, each of the pivot members 402,404 includes an
aperture 403,408,412 structured to receive a suitable pivot 158 of the carrier assembly
101 (Figure 2) in order that it is pivotably coupled between a corresponding pair of the
pivot members, such as 402,404, as shown. The pivot 158 may comprise any suitable
pivot such as, for example and without limitation, at least one pivot pin, such as the first
and second pivot pins 160,162 extending outwardly, generally perpendicularly from the
first and second carrier members 102,104 of the carrier assembly 101 in Figure 4.
Figures 7 and 8 respectively show the two types of pivot members 402 and
404 which comprise the example pivot assembly 400 (Figures 1, 9 and 10). More
specifically, each of the one-piece molded pivot members 402,404 includes the aperture
403 (Figure 7), 408 (Figure 8), 412 (shown in hidden line drawing in Figures 8 and 10;
see also Figure 9) which is a substantially circular pivot recess 403 (Figure 7), 408
(Figure 8), 412 (shown in hidden line drawing in Figures 8 and 10; see also Figure 9)
having a full, continuous circumference 414.
End pivot member 402 of Figure 7 includes a pair of lateral extensions
424,425 which extend outwardly from the pivot recess 403. In the example shown and
described herein, at least one of the lateral extensions 424,425 includes at least one
protrusion, such as the single tab 426 (best shown in Figure 7) extending generally
perpendicularly from lateral extension 425 of the pivot member 402. Each of the end
pivot members 402 in the example shown and described, also includes at least one cut-
out portion, such as, for example and without limitation, the pair of cut-out portions 430
in each of the lateral extensions 424,425 of the example end pivot member 402, shown.
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Each end pivot member 402 also has a width 432 which, as will be discussed
hereinbelow, is equal to or greater than the width of the walls 24,26,28,30 (Figures 1 and
9) of the circuit breaker housing 3 (Figure 1, and Figures 9-11). It will, however, be
appreciated that the end pivot members 402 of the pivot assembly 400 (Figures 1, 9, and
10) could comprise any known or suitable alternative configuration and number of
recesses and protrusions other than those shown and described herein, without departing
from the scope of the invention. For example and without limitation, the pivot members
402 could alternatively have a combination (not shown) of protrusions but no recesses, or
a combination (not shown) of recesses but no protrusions.
Figure 8 shows an intermediate pivot member 404 of the pivot assembly
400 (Figures 1, 9, and 10). Each of the intermediate pivot members 404 has a perimeter
416 with at least one protrusion such as, for example, rib 422, which extends outwardly
from a first portion 418 of the perimeter 416, and at least one recess such as, for example,
elongated recess 428, within a second portion 420 of the perimeter 416. The rib 422 and
elongated recess 428, like the aforementioned tab 426 and cut-out portions 430 of end
pivot member 402 discussed in connection with Figure 7, function to secure the pivot
member 404 between the molded cover 4 and molded base 5 of the circuit breaker
housing 3, as will be discussed in greater detail hereinbelow, for example with respect to
Figure 10. Like end pivot member 402, intermediate pivot member 404 is a one-piece
molded member having a first pivot recess 408 in the first side 406 thereof, wherein the
first pivot recess 408 has a full, continuous diameter 414. However, unlike end pivot
member 402, each of the intermediate pivot members 404 further includes a second side
410 having a second pivot recess 412 (see, for example, Figure 9). In this manner, in
operation, each intermediate pivot member 404 receives and pivotably secures the pivot
members 158 (Figure 1) of two different carrier assemblies 101 (one carrier assembly
101 is shown in Figure 1, for ease of illustration), one on the first side 406 and the other
on the second side 410 of the intermediate pivot member 404.
At least one of the protrusions 422,426 of the respective pivot members
404,402 is structured to engage one of the molded cover 4 and the molded base 5 of the
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circuit breaker housing 3, and at least one of the cut-out portions 428,430 of the
respective pivot members 404,402 is structured to engage the other of the molded cover 4
and molded base 5 in order to clam-shell the pivot members 402,404 therebetween, as
previously discussed.
As employed herein, the term "clam-shell" refer to the nature in which the
pivot members 402,404 are secured (e.g., sandwiched) between the molded cover 4 and
molded base 5 of the circuit breaker housing 3, without requiring the use of separate
fasteners. More specifically, as shown in Figure 9, the circuit breaker 2 has a plurality of
poles 18,20,22, and includes a carrier assembly 101 for each of these poles (one carrier
assembly 101 is shown for simplicity of illustration). The circuit breaker housing 3
comprises a plurality of substantially vertical walls 24,26 and 28,30 molded in the
molded base 5 and molded cover 4, respectively, of the circuit breaker housing 3. When
the molded cover 4 and molded base 5 are assembled, as shown in Figure 10, each of the
substantially vertically walls 24,26 of the molded base 5 generally aligns with a
corresponding one of the substantially vertical walls 28,30 of the molded cover 4 to form
a plurality of separate cavities 32,34,36 for the poles 18,20,22 of the circuit breaker 2.
Each of the aforementioned pivot members 402,404 of the pivot assembly 400 is clam-
shelled between the corresponding pair of substantially vertical walls 24,26 of the molded
base 5 and the substantially vertical walls 28,30 of the molded cover 4, thereby providing
substantially unobstructed access to the separate cavities 32,34,36 within the circuit
breaker housing 3. In this manner, the pivot assembly 400 enables a circuit breaker
housing 3 to accommodate a wide variety of circuit breaker component designs. For
example and without limitation, it is the clam-shelled pivot assembly design which, in
large part, enables the use of the solid conductor 52 of the conductor assembly 50,
previously discussed in connection with Figures 1-3, and provides space to receive
additional components such as, for example and without limitation, a sensor (not shown).
Continuing to refer to Figure 9, the pivot assembly 400 for the three-pole
low-voltage circuit 2 includes four pivot members 402,404, a pair of the aforementioned
end pivot members 402 disposed at or about the first and second sides 7,9 of the circuit
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breaker housing 3, and a pair of the aforementioned intermediate pivot members 404
disposed between the end pivot members 402 at an intermediate portion 11 of the circuit
breaker housing 3, as shown. More specifically, the tab 426 of each end pivot member
402 engages a corresponding recess 38 (best shown in Figures 1 and 9) of the molded
base 5 of the circuit breaker housing 3 and the cut-out portions 430 and lateral extensions
424,425 of each end pivot member 402 are received within a corresponding recess 38 in
the molded cover 4 of the circuit breaker housing 3, as best shown in Figure 11, to clam-
shell the end pivot members 402 between the molded cover 4 and molded base 5 of the
circuit breaker housing 3, as previously discussed. Each intermediate pivot member 404
is similarly clam-shelled by the rib 422 of the intermediate pivot member 404 engaging a
corresponding recess 38' of the molded cover 4 of the circuit breaker housing 3, as best
shown in Figures 10 and 11, and the elongated recess 428 of the intermediate pivot
member 404 receiving the corresponding protrusion 40 (e.g., without limitation, portion
40 of substantially vertical wall 26) of the molded base 5 of the circuit breaker housing 3.
In addition to the aforementioned advantages (e.g., without limitation,
accommodation of manufacturing tolerance discrepancies; improved alignment between
circuit breaker components), the pivot members 402,404 of the pivot assembly 400 also
serve to provide a superior dielectric barrier 436 (Figures 9 and 10) between poles
18,20,22 (Figure 9) of the circuit breaker 2, in order to electrically isolate one pole
18,20,22 from another. This advantage is afforded both by the aforementioned protrusion
(e.g., rib 422) and recess (e.g., recess 38') closely fitting clam-shelled structure of the
pivot assembly 400, which can best be appreciated with reference to the cross-sectional
view of Figure 10, and also to the fact that the first widths 432 (best shown in Figure 7),
434 (best shown in Figure 8) of the end pivot members 402 and intermediate pivot
members 404 are greater than the second widths 42,44 (Figure 9) of the walls 24,26
(Figure 9), respectively, of the circuit breaker housing 3 (Figure 9). Thus, it will be
appreciated that the pivot members 402 are separate pieces, the increased widths 432,434
of which provide superior mechanical bearing support while simultaneously permitting
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widths 42,44 of the walls 24,26, for example, to be thinner, thereby providing increased
interior space.
Figures 1 and 9-12 show another feature of the example low-voltage
circuit breaker 2 (Figures 1, 9 and 10) which is structured to address and overcome the
aforementioned manufacturing tolerance discrepancy and alignment issues among and
between circuit breaker components (e.g., without limitation, stationary contact
assembly; movable contact assembly; carrier assembly; operating mechanism) which
result, for example, between a first circuit component (e.g., without limitation, stationary
contact assembly; movable contact assembly; carrier assembly; operating mechanism)
which is mounted to a first portion or section (e.g., without limitation, exterior side 13' of
molded base 5 of Figure 1) of one part (e.g., without limitation molded base 5) of the
circuit breaker housing 3 and coupled to at least one other component (e.g., without
limitation, stationary contact assembly; movable contact assembly; carrier assembly;
operating mechanism) mounted to another portion or section (e.g., without limitation,
interior side 15' of molded base 5 of Figure 1) of the same part (e.g., without limitation,
molded base 5). In other words, such issues result as a consequence of the parting line, as
defined herein, of the individual component. It will, however, be appreciated that they
also occur across the mating line, as defined herein, between separate components of the
breaker 2 such as, for example and without limitation, the mating line between the first
half (e.g., molded cover 4 of Figure 1) of the circuit breaker housing (e.g., housing 3 of
Figure 1) and on the second half (e.g., molded base 5 of Figure 1) of the housing (e.g.,
housing 3 of Figure 1). Specifically, a bearing assembly 500 is employed which
pivotably supports the pole shaft 19 of the circuit breaker operating mechanism 17
substantially independent of the mating line between the molded cover 4 and molded
base 5 of the circuit breaker housing 3, and of the parting line(s) of any and all
intermediate part(s) interposed therebetween. The bearing assembly 500 also pivotably
couples and supports the pole shaft 19 on the same side of the parting line of the molded
base 5 as the stationary contact assembly 10 of the circuit breaker 2. Accordingly,
misalignment across the parting line and/or mating the line 60, which is/are prevalent in
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the known prior art, is substantially eliminated. In the example low-voltage circuit
breaker 2 of Figure 1, the pole shaft 19 is disposed substantially entirely outside of the
molded cover 4 while being substantially supported on the molded base 5 of the circuit
breaker housing 3. Such configuration of the pole shaft 19 is made possible by the
bearing assembly 500 in accordance with embodiments of the invention, which will now
be discussed. It will be appreciated that not all of the components of the bearing
assembly 500 are shown in each of Figures 1 and 9-12. In particular, several components
are not shown in Figures 9 and 10 which respectively show the bearing assembly 500
assembled, and a cross-section of a portion of the bearing assembly 500.
The bearing assembly 500 includes a number of primary bearings 530,531,
(Figures 1 and 10), an integral bearing section 502 (not expressly shown in Figure 9; best
shown in Figure 12), and at least one bearing cover member 503,504,506,508 (only one
cover member 506 is shown in the cross-sectional view of Figure 10). Each cover
member 503,504,506,508 includes a bearing surface 509,510,512,514 and a fastening
portion 515,516,518,520. The fastening portions 515,516,518,520 are structured to
couple the bearing cover members 503,504,506,508 to the molded cover 4 in order that
the pole shaft 19 of the operating mechanism 17 is pivotably disposed between the
integral bearing section 502 and the bearing surfaces 509,510,512,514 of the bearing
cover members 503,504,506,508 on the exterior side 13 of the molded cover 4, as best
shown in Figures 9 and 12. More specifically, the integral bearing section 502 is
"integral" in the sense that it comprises a plurality of molded portions 522,524,526 which
are molded directly into the exterior surface 13 of the molded cover 4, as best shown in
Figure 12. It will, however, be appreciated that the pole shaft 19 could alternatively be
pivotably disposed, for example and without limitation, on the exterior side 13' of the
molded base 5 of the circuit breaker housing 3, without departing from the scope of the
invention.
The molded portions 522,524,526 of the integral bearing section 502
generally comprise a number of molded first semi-circles 522,526 which are structured to
receive the generally cylindrical shaft 21 of pole shaft 19, thereby forming the first part of
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a secondary pole shaft bearing 528,532. The second part of the secondary pole shaft
bearing (two secondary pole shaft bearings 528,532 are shown in the example bearing
assembly 500 illustrated and described herein) is formed by the bearing surface 509,514
of a corresponding bearing cover member 503,508 each of which comprises a second
semi-circle 509,514. When the fastening portion 515,516,518,520 of each bearing cover
member 503,504,506,508 is coupled to the molded cover 4 of housing 3, each first semi-
circle 522,526 of integral bearing section 502 aligns with the second semi-circle 509,514
of a corresponding one of the bearing cover members 503,508, in order to form the
secondary pole shaft bearings 528,532.
More importantly, the pole shaft 19 is pivotably supported by the primary
bearings 530,531. Specifically, the example bearing assembly 500 includes two primary
bearings 530,531 which provide the primary support for the pole shaft 19. The primary
bearings 530,531, as will be discussed herein, pivotably couple and support the pole shaft
19 on the same side (e.g., interior side 15') of the parting line of the molded base 5 as the
stationary contact assembly 10 of the circuit breaker 2. In this manner, the disadvantages
(e.g., without limitation, misalignment) commonly associate with the parting line(s) of
each individual component or group of components, and the mating line(s) between
components, are eliminated because the relationship between the pole shaft 19 and
stationary contact assembly 10 does not cross the parting line(s) and/or mating line(s).
This relationship can be best appreciated with reference to the cross-sectional view of
Figure 10, which shows primary bearing 530, in detail.
The example bearing assembly 500 includes four bearing cover members
503,504,506,508, a first molded bearing cover 503, a second molded bearing cover 504, a
third molded bearing cover 506, and a fourth molded bearing cover 508. It will,
however, be appreciated that any known or suitable number of bearing cover members
having any known or suitable configuration could alternatively be employed. For
example and without limitation, a single-piece bearing cover member (not shown) could
be used. The fastening portions 515,516,518,520 of the example first, second, third and
fourth molded bearing cover members 503,504,506,508 respectively include at least one
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opening 533,534,536,538 and fasteners, such as the screws 540,540' which are shown.
The screws 540,540' are inserted through the corresponding openings 533,534,536,538
and are tightened to secure the corresponding bearing cover members 503,504,506,508 to
the exterior side 13 of the molded cover 4 of circuit breaker molded housing 3. It will,
however, be appreciated that any known or suitable alternative fastening mechanism
other than the example fasteners 540,540' shown and described herein, could be
employed. The molded cover members 503,504,506,508 and the remainder of the
bearing assembly 500 are shown assembled in Figures 9 (shown without fasteners
540,540'; see also Figure 10 showing fasteners 540).
As previously noted, the pole shaft 19 comprises a generally cylindrical
shaft 21. The generally cylindrical shaft 21 includes a plurality of levers 23 extending
generally outwardly therefrom, as shown in Figures 1 and 10-12. In order to
accommodate movement of such levers 23, each of the bearing cover members
503,504,506,508 further includes a plurality of first molded passages 550,552,554
structured to permit pivoting of the pole shaft 19 and, in particular, levers 23 of the pole
shaft 19. Likewise, the integral bearing section 502 includes a plurality of second molded
passages 556,558,560 for receiving the levers 23 when the pole shaft 19 pivots. The
example pole shaft 19 includes three levers 23 protruding outwardly from the generally
cylindrical shaft 21. The three levers 23 are respectively accommodated by three first
molded passages 550,552,554 in the first, second and third molded bearing cover
members 504,506,508 and three corresponding second molded passages 556,558,560 in
the integral bearing section 502 of the bearing assembly 500.
At least one of the bearing cover members 503,504,506,508 additionally
includes at least one aperture 542,544 for providing access to a portion of the pole shaft
19 from the exterior side 13 of the molded cover 4 when the bearing assembly 500 is
assembled, as best shown in Figure 9. In this manner, at least partial access to the pole
shaft 19 is provided in order to, for example and without limitation, sense or view the
position of the pole shaft 19, inspect, and/or maintain (e.g., without limitation, lubricate)
the pole shaft 19 without requiring the entire bearing assembly 500 to be disassembled.
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Hence, because the bearing assembly 500 is substantially disposed on the exterior side 13
of the circuit breaker housing 3 and substantially entirely on one side of the mating line
60 of the circuit breaker housing 3, as opposed to being disposed at or about the mating
line 60 between the molded cover 4 and molded base 5 of the housing 3, as is sometimes
the case in the known prior art, the bearing assembly 500 and pole shaft 19 can be
relatively easily accessed from the exterior side 13 of the housing 3 without having to
entirely separate the molded cover 4 and molded base 5. The example bearing assembly
500 includes two apertures 542,544 in the first molded bearing cover member 503 and
fourth molded bearing cover member 508, respectively, although it will be appreciated
that any known or suitable number of apertures, or that no apertures whatsoever, could be
employed without departing from the scope of the invention. It will also be appreciated
that the apertures 542,544, in addition to serving the aforementioned access function for
providing access to pole shaft 19, can also serve to further accommodate pivotable
motion of the aforementioned levers 23 of the pole shaft 19.
As previously discussed, the example bearing assembly 500 includes two
primary bearings 530,531. The first half of each primary bearing 530,531 (one primary
bearing 530 is best shown in Figure 10) comprises a molded extension 546 of the molded
base 5 of the circuit breaker housing 3. Specifically, the molded cover 4 and molded base
5 each further include an interior side 15', 15 and, as discussed previously, substantially
vertical walls 24,26,28,30 extend outwardly from the interior side 15',15 of the molded
cover 4 and molded base 5, respectively. The molded extensions 546, two of which are
shown in the example bearing assembly 500 of Figures 1 and 9, comprise molded
extensions 546 of the substantially vertical walls 26 of the molded cover 4 (best shown in
Figure 10). As best shown in Figure 10, the molded extension 546 is coupled to a
corresponding one of the integral bearing cover members 506 of the bearing assembly
500 proximate a corresponding one of the molded portions (e.g., molded portion 524 of
Figure 10) thereof in order to support the pole shaft 19 of the operating mechanism 17.
The bearing cover member 506, thus serves as the second half of the integral bearing 530.
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A corresponding substantially vertical wall 30 of the molded cover 4 of
housing 3 includes a molded recess 548 (best shown in Figure 11) structured to receive
the molded extension 546 of substantially vertical wall 26 of the molded base 5, as shown
in Figure 10, and the aforementioned fasteners 540 (one fastener 540 is shown in Figure
10) are inserted through opening 536 of the bearing cover member 506 and into a
corresponding opening 537 of the molded extension 546. The fastener 540 then engages
a second fastening mechanism 541, such as, for example and without limitation, a
threaded component (e.g., without limitation, a nut), and is tightened to secure the
bearing assembly 500 together. It will, however, be appreciated that any other known or
suitable fastening mechanism other than the pair of fastening components 540,541 which
are shown, could be employed without departing from scope of the invention.
Accordingly, the bearing assembly 500 provides a cost effective
mechanism for addressing and overcoming alignment issues with respect to different
portions or sections of the same component(s) (e.g., across the parting Iine(s)) of the
circuit breaker 2, and/or between the various separate components (e.g., across the mating
line(s)) of the circuit breaker 2. The bearing assembly 500 also provides for relatively
easy assembly and access of the circuit breaker pole shaft 19, for example, for inspection
and/or maintenance, without requiring complete disassembly of the entire circuit breaker
2.
While specific embodiments of the invention have been described in
detail, it will be appreciated by those skilled in the art that various modifications and
alternatives to those details could be developed in light of the overall teachings of the
disclosure. Accordingly, the particular arrangements disclosed are meant to be
illustrative only and not limiting as to the scope of the invention which is to be given the
full breadth of the claims appended and any and all equivalents thereof.
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REFERENCE CHARACTER LIST
2 electrical switching apparatus
3 housing
4 molded cover
5 molded base
6 first electrical conductor
7 first side
8 second electrical conductor
9 second side
10 stationary contact assembly
11 intermediate portion
12 stationary electrical contact
13 exterior side
13' exterior side
14 first contact portion
15 interior side
15' interior side
16 second contact portion
17 operating mechanism
18 pole
19 pole shaft
20 pole
21 cylindrical shaft
22 pole
23 lever
24 wall
26 wall
28 wall
30 wall
32 cavity
34 cavity
36 cavity
38 recess
38' recess
40 protrusion
42 first thickness
44 first thickness
50 conductor assembly
52 load conductor
53 first portion
54 first aperture
55 second portion
56 interior arcuate portion
58 neck portion
60 parting line
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100 movable contact assembly
101 carrier assembly
102 first carrier member
104 second carrier member
106 toe portion
108 heel portion
110 movable contact arm
112 first end
114 second end
116 second aperture
118 interior arcuate portion
120 neck portion
122 profile
124 axis
126 slot
128 slot
130 movable electrical contact
132 pivot pin
134 aperture
136 arrow
138 arrow
140 arrow
150 electrically insulative spacers
152 first insulating portion
154 connection portion
156 second insulating portion
158 pivot
160 first pivot pin
162 second pivot pin
200 flexible conductive element
201 arrow
202 first end
203 arrow
204 second end
206 first bend
208 second bend
210 first portion
212 second portion
214 third portion
220 axis
222 first angle
224 second angle
226 first generally round head
228 second generally round head
230 conductive ribbon
232 first pin

05-EDP-358
234 second pin
300 contact spring assembly
302 first contact spring housing member
304 second contact spring housing member
306 spring guide
308 spring hole
310 slider
312 spring
314 first end
316 second end
326 first end
328 second end
330 cam element
332 guide slot
334 guide slot
340 first side
342 first protrusion
344 second side
346 second protrusion
348 recess
350 first end
352 first end
354 second end
356 second end
358 intermediate portion
360 intermediate portion
362 folded tab
364 folded tab
366 protrusion
368 protrusion
370 unfolded tab
372 unfolded tab
374 aperture
376 aperture
378 lateral protrusion
380 lateral protrusion
382 recess
384 recess
386 first side
388 first protrusion
390 second side
392 second protrusion
400 pivot assembly
402 end pivot member
403 aperture
404 intermediate pivot member
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406 first side
408 first pivot recess
410 second side
412 second pivot recess
414 circumference
416 perimeter
418 first portion of perimeter
420 second portion of perimeter
422 rib
424 lateral extension
425 lateral extension
426 tab
428 elongated recess
430 cut-out portion
432 second thickness
434 second thickness
436 dielectric barrier
500 bearing assembly
502 integral bearing section
504 first bearing cover member
506 second bearing cover member
508 third bearing cover member
510 bearing surface
512 bearing surface
514 bearing surface
516 fastening portion
518 fastening portion
520 fastening portion
522 molded portion
524 molded portion
526 molded portion
528 pole shaft bearing
530 pole shaft bearing
532 pole shaft bearing
533 opening
534 opening

536 opening
537 opening
538 opening
540 fastener
540' fastener
541 fastener
542 aperture
544 aperture
546 bearing support
548 molded recess
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550 first molded passage
552 first molded passage
554 first molded passage
556 second molded passage
558 second molded passage
560 second molded passage

33

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What is claimed is:
1. A bearing assembly (500) for an electrical switching apparatus (2) including a
housing (3) having at least one parting line and an exterior side (13,13'), a stationary
contact assembly (10) disposed on one side of said parting line of said housing (3), a
movable contact assembly (100), and an operating mechanism (17) including a pole shaft
(19) for moving said movable contact assembly (100) into and out of electrical contact
with said stationary contact assembly (10), said bearing assembly (500) comprising:
a number of primary bearings (530,531) structured to pivotably support
said pole shaft (19) of said operating mechanism (17) on the same side of said parting
line of said housing (3) as said stationary contact assembly (10) of said electrical
switching apparatus (2);
an integral bearing section (502) structured to pivotably couple said pole
shaft (19) of said operating mechanism (17) to said housing (3) of said electrical
switching apparatus (2); and
at least one bearing cover member (503,504,506,508) including a bearing
surface (509,510,512,514) and a fastening portion (515,516,518,520) structured to be
coupled to the exterior side (13,13') of said housing (3) of said electrical switching
apparatus (2),
wherein when said fastening portion (515,516,518,520) of said at least one
bearing cover member (503,504,506,508) is coupled to the exterior side (13,13') of said
housing (3), said pole shaft (19) of said operating mechanism (17) is pivotably disposed
between said integral bearing section (502) and said bearing surface (509,510,512,514) of
said at least one bearing cover member (503,504,506,508) on the exterior side (13) of
said housing (3).
2. The bearing assembly (500) of claim 1 wherein said pole shaft (19) of said
operating mechanism (17) is generally cylindrical in shape; and wherein said integral
bearing section (502) comprises a plurality of molded portions (522,524,526) structured
to be molded on the exterior side (13,13') of said housing (3) of said electrical switching
apparatus (2) in order to receive said generally cylindrical pole shaft (19).

05-EDP-358
3. The bearing assembly (500) of claim 2 wherein said at least one bearing
cover member is a plurality of bearing cover members (503,504,506,508); wherein said
integral bearing section (502) and a number of said bearing cover members (503)
combine to form a plurality of secondary pole shaft bearings (532); wherein each of said
secondary pole shaft bearings (532) has a first part (522,526) and a second part (509);
wherein said molded portions (522,526) of said integral bearing section (502) comprise
the first part (522,526) of one of said secondary pole shaft bearings (532); and wherein
said bearing surface (509) of each of said bearing cover members (503) comprises the
second part (509,514) of said one of said secondary pole shaft bearings (532).
4. The bearing assembly (500) of claim 3 wherein said molded portions
(522,526) of said integral bearing section (502) comprise a plurality of molded first semi-
circles (522,526); wherein said bearing surface (509,514) of each of said bearing cover
members (503,508) comprises a second semi-circle (509,514); and wherein when said
fastening portion (515,516,518,520) of each of said bearing cover members
(503,504,506,508) is coupled to the exterior side (13,13') of said housing (3) of said
electrical switching apparatus (2), each of said molded first semi-circles (522,526) of said
integral bearing section (502) aligns with said second semi-circle (509,514) of a
corresponding one of said bearing cover members (503,508) in order to form a
corresponding one of said secondary pole shaft bearings (528,532).
5. The bearing assembly (500) of claim 1 wherein said fastening portion
(515,516,518,520) of said at least one bearing cover member (503,504,506,508)
comprises at least one opening (534,536,538) and at least one fastener (540,540'); and
wherein a corresponding one of said at least one fastener (540,540') is disposed in a
corresponding one of said at least one opening (534,536,538) of said fastening portion
(515,516,518,520) of said at least one bearing cover member (503,504,506,508) and
tightened, in order to secure each of said at least one bearing cover member
(503,504,506,508) to the exterior surface (13,13') of said housing (3) of said electrical
switching apparatus (2).
6. The bearing assembly (500) of claim 1 wherein said at least one bearing
cover member comprises a first molded cover member (503), a second molded cover
member (504), a third molded cover member (506), and a fourth molded cover member
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05-EDP-358
(508); and wherein at least one of said first molded cover member (503), said second
molded cover member (504), said third molded cover member (506), and said fourth
molded cover member (508), includes an aperture (542,544) structured to provide access
to a portion of said pole shaft (19) of said operating mechanism (17) from the exterior
side (13,13') of said housing (3) of said electrical switching apparatus (2).
7. A housing (3) for an electrical switching apparatus (2) including a
stationary contact assembly (10), a movable contact assembly (100), and an operating
mechanism (17) including a pole shaft (19) for moving said movable contact assembly
(100) into and out of electrical contact with said stationary contact assembly (10), said
housing (3) comprising:
a molded cover (4) having an exterior side (130,131) and a parting line;
a molded base (5) disposed generally opposite from and coupled to said
molded cover (4), said molded base (5) including a parting line and an exterior side
(13,13% said molded base (5) being structured to receive said stationary contact assembly
(10) of said electrical switching apparatus (2) on one side of said parting line of said
molded base (5); and
a bearing assembly (500) comprising:
a number of primary bearings (530,531) structured to pivotably
support said pole shaft (19) of said operating mechanism (17) of said electrical switching
apparatus (2) on the same side of said parting line of said molded base (5) as said
stationary contact assembly (10),
an integral bearing section (502), and
at least one bearing cover member (503,504,506,508) including a
bearing surface (509,510,512,514) and a fastening portion (515,516,518,520),
wherein said fastening portion (515,516,518,520) of said at least
one bearing cover member (503,504,506,508) couples said at least one bearing cover
member (503,504,506,508) to one of said molded cover (4) and said molded base (5), in
order that said pole shaft (19) of said operating mechanism (17) is pivotably disposed
between said integral bearing section (502) and said bearing surface (509,510,512,514) of
said at least one bearing cover member (503,504,506,508) on the exterior side (13,13') of
said one of said molded cover (4) and said molded base (5).
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05-EDP-358
8. The housing (3) of claim 7 wherein said pole shaft (19) of said operating
mechanism (17) is generally cylindrical in shape; wherein said integral bearing section
(502) comprises a plurality of molded portions (522,524,526) molded in said one of said
molded cover (4) and said molded base (5) in order to receive said generally cylindrical
pole shaft (19); wherein said at least one bearing cover member (503,504,506,508) is a
plurality of bearing cover members (503,504,506,508); wherein a number of said bearing
cover members (503,508) combine with said integral bearing section (502) to form a
plurality of secondary pole shaft bearings (528,532) each having a first part (522,526)
and a second part (510,514); wherein said molded portions (522,526) of said integral
bearing section (502) comprise said first part (522,526) of one of said secondary pole
shaft bearings (528,532); and wherein said bearing surface (509,514) of each of said
bearing cover members (503,508) comprises the second part (509,514) of said one of said
secondary pole shaft bearings (528,532).
9. The housing (3) of claim 8 wherein said molded portions (522,526) of said
integral bearing section (502) comprise a plurality of molded first semi-circles (522,526)
disposed in said molded base (5) of said housing (3); wherein said bearing surface
(509,514) of each of said bearing cover members (503,508) comprises a second semi-
circle (509,514); and wherein when said fastening portion (515,520) of each of said
bearing cover members (503,508) is coupled to said molded base (5) of said housing (3),
each of said molded first semi-circles (522,526) of said integral bearing section (502)
aligns with said second semi-circle (509,514) of a corresponding one of said bearing
cover members (503,508) in order to form said secondary pole shaft bearings (528,532).
10. The housing (3) of claim 9 wherein said molded cover (4) and said molded
base (5) each further comprise an interior side (15,15') and a number of substantially
vertical walls (24,26,28,30) extending outwardly from said interior side (15,15'); wherein
each of said primary bearings (530,531) of said bearing assembly (500) comprises a
molded extension (546) of one of said substantially vertical walls (26) of said molded
base (5); and wherein said molded extension (546) couples to a corresponding one of said
molded cover members (504,506) of said integral bearing section (502) proximate at least
one of said molded portions (522,524,526) of said integral bearing section (502) in order
to support said pole shaft (19) of said operating mechanism (17).
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05-EDP-358
11. The housing (3) of claim 10 wherein said bearing assembly (500) further
comprises a plurality of fasteners (540,540'); wherein said plurality of bearing cover
members comprises a first molded cover member (503), a second molded cover member
(504), a third molded cover member (506), and a fourth molded cover member (508); and
wherein at least one of said first molded cover member (503), said second molded cover
member (504), and said third molded cover member (506), and said fourth molded cover
member (508) is coupled to said at least one molded extension (546) of said one of said
substantially vertical walls (26) by at least one of said fasteners (540,540').
12. The housing (3) of claim 10 wherein at least one of said substantially
vertical walls (30) of said molded cover (4) extending from the interior side (15) of said
molded cover (4) of said housing (3) comprises a molded recess (548); and wherein when
said molded cover (4) is coupled to said molded base (5), said molded extension (546) of
said one of said substantially vertical walls (26) of said molded base (5) is disposed
within said molded recess (548) of a corresponding one of said at least one substantially
vertical walls (30) of said molded cover (4).
13. The housing (3) of claim 7 wherein said molded cover (4) and said molded
base (5) are joined at a mating line (60); and wherein said pole shaft (19) of said
operating mechanism (17) is substantially disposed on the exterior side (13,13') of one of
said molded cover (4) and said molded base (5) of said housing (3) and is substantially
pivotably coupled to and supported by said primary bearings (530,531) of the other one
of said molded cover (4) and molded base (5), thereby being substantially independent of
dimensional and tolerance variations across said mating line (60).
14. An electrical switching apparatus (2) comprising:
a stationary contact assembly (10) having a plurality of stationary
electrical contacts (12);
a movable contact assembly (100) having a plurality of movable contact
arms (110) and a plurality of movable electrical contacts (130) coupled to said movable
contact arms (110);
an operating mechanism (17) including a pole shaft (19) for moving said
movable contact arms (110) and said movable electrical contacts (130) coupled thereto
38

05-EDP-358
into and out of electrical contact with said stationary electrical contacts (12) of said
stationary contact assembly (10); and
a housing (3) comprising:
a molded cover (4) having an exterior side (13,13') and a parting
line,
a molded base (5) disposed generally opposite from and coupled to
said molded cover (4), said molded base (5) including a parting line and an exterior side
(13,13'), said molded base (5) receiving said stationary contact assembly (10) of said
electrical switching apparatus (2) on one side of said parting line of said molded base (5),
and
a bearing assembly (500) comprising:
a number of primary bearings (530,531) pivotably
supporting said pole shaft (19) of said operating mechanism (17) of said electrical
switching apparatus (2) on the same side of said parting line of said molded base (5) as
said stationary contact assembly (10),
an integral bearing section (502), and
at least one bearing cover member (503,504,506,508)
including a bearing surface (509,510,512,514) and a fastening portion (515,516,518,520),
wherein said fastening portion (515,516,518,520) of said at
least one bearing cover member (503,504,506,508) couples said at least one bearing
cover member (503,504,506,508) to one of said molded cover (4) and said molded base
(5), in order that said pole shaft (19) of said operating mechanism (17) is pivotably
disposed between said integral bearing section (502) and said bearing surface
(509,510,512,514) of said at least one bearing cover member (503,504,506,508) at or
about the exterior side (13,13') of said one of said molded cover (4) and said molded base
(5).
15. The electrical switching apparatus (2) of claim 14 wherein said pole shaft
(19) of said operating mechanism (17) is generally cylindrical in shape; wherein said
integral bearing section (502) comprises a plurality of molded portions (522,524,526)
molded in said one of said molded cover (4) and said molded base (5) in order to receive
said generally cylindrical pole shaft (19); wherein said at least one bearing cover member
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05-EDP-358
is a plurality of bearing cover members (503,504,506,508); wherein a number of said
bearing cover members (503,504,506,508) combine with said integral bearing section
(502) to form a plurality of secondary pole shaft bearings (528,532) each having a first
part (522,526) and a second part (509,514); wherein said molded portions (522,526) of
said integral bearing section (502) comprise said first part (522,526) of one of said
secondary pole shaft bearings (528,532); and wherein said bearing surface (509,514) of
each of said bearing cover members (503,508) comprises the second part (509,514) of
said one of said secondary pole shaft bearings (528,530,532).
16. The electrical switching apparatus (2) of claim 15 wherein said molded
portions (522,526) of said integral bearing section (502) comprise a plurality of molded
first semi-circles (522,526) disposed in said molded base (5) of said housing (3); wherein
said bearing surface (509,514) of each of said bearing cover members (503,508)
comprises a second semi-circle (509,514); and wherein when said fastening portion
(515,520) of each of said bearing cover members (503,508) is coupled to said molded
base (5) of said housing (3), each of said molded first semi-circles (522,526) of said
integral bearing section (502) aligns with said second semi-circle (509,514) of a
corresponding one of said bearing cover members (503,508) in order to form said
secondary pole shaft bearings (528,530,532).
17. The electrical switching apparatus (2) of claim 16 wherein said molded
cover (4) and said molded base (5) each further comprise an interior side (15,15') and a
number of substantially vertical walls (24,26,28,30) extending outwardly from said
interior side (15,15'); wherein each of said primary bearings (530,531) of said bearing
assembly (500) comprises a molded extension (546) of one of said substantially vertical
walls (26) of said molded base (5); and wherein said molded extension (546) couples to a
corresponding one of said molded cover members (504,506) of said integral bearing
section (502) proximate at least one of said molded portions (522,524,526) of said
integral bearing section (502) in order to support said pole shaft (19) of said operating
mechanism (17).
18. The electrical switching apparatus (2) of claim 17 wherein said bearing
assembly (500) further comprises a plurality of fasteners (540,540'); wherein said bearing
cover members comprise a first molded cover member (503), a second molded cover
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05-EDP-358
member (504), a third molded cover member (506), and a fourth molded cover member
(508); and wherein at least one of said first molded cover member (503), said second
molded cover member (504), and said third molded cover member (506), and said fourth
molded cover member (508) is coupled to said molded extension (546) of said one of said
substantially vertical walls (26) by at least one of said fasteners (540,540').
19. The electrical switching apparatus (2) of claim 17 wherein at least one of
said substantially vertical walls (30) of said molded cover (4) extending from the interior
side (15) of said molded cover (4) of said housing (3) comprises a molded recess (548);
and wherein when said molded cover (4) is coupled to said molded base (5), said molded
extension (546) of said one of said substantially vertical walls (26) of said molded base
(5) is disposed within said molded recess (548) of a corresponding one of said at least one
substantially vertical walls (30) of said molded cover (4).
20. The electrical switching apparatus (2) of claim 14 wherein said pole shaft
(19) comprises a generally cylindrical shaft (21) and a plurality of levers (23) extending
outwardly from said generally cylindrical shaft (21); wherein said at least one bearing
cover member is a plurality of bearing cover members (503,504,506,508); wherein each
of said bearing cover members (503,504,506,508) further comprises a plurality of first
molded passages (550,552,554) for receiving said levers (23) of said pole shaft (19) when
said pole shaft (19) pivots; wherein said integral bearing section (502) comprises a
plurality of molded bearing portions (522,524,526) for pivotably receiving said generally
cylindrical shaft (21) of said pole shaft (23), and a plurality of second molded passages
(556,558,560) for receiving said levers (23) of said pole shaft (19) when said pole shaft
(19) pivots; wherein when said fastening portion (515,516,518,520) of each of said
bearing cover members (503,504,506,508) is fastened to said one of said molded cover
(4) and said molded base (5), said bearing surface (509,510,512,514) of each of said
bearing cover members (504,506,508) combines with a corresponding one of said molded
bearing portions (522,524,526) of said integral bearing section (502) in order to form a
plurality of secondary pole shaft bearings (528,532); and wherein said secondary pole
shaft bearings (528,532) pivotably receive said generally cylindrical shaft (21) of said
pole shaft (19).

A bearing assembly (500) is provided for an electrical switching apparatus (2) including a housing (3) having at least one parting line and an exterior side (13,13'), a stationary contact assembly (10) disposed on one side of the parting line, a movable contact assembly (100), and an operating mechanism (17) with a pole shaft (19) for moving the movable contact assembly (100) into and out of electrical contact with the stationary contact assembly (10). The bearing assembly (500) includes a number of primary bearings (530,531) pivotably supporting the pole shaft (19) on the same side of the parting line as the stationary contact assembly (10). An integral bearing section (502)
including secondary bearings (528,532) pivotably couples the pole shaft (19) to the housing (3) using at least one bearing cover member (503,504,506,508) having a fastening portion (515,516,518,520). The pole shaft (19) is pivotably disposed at or about the integral bearing section (502) on the exterior side (13,13') of the housing (3). A housing (3) and an electrical switching apparatus (2) are also disclosed.