Cross Reference To Related Applications
The subject matter of this invention is related to concurrently filed, co-pending
applications: U.S. Patent Application Serisl No. / Eaton Docket No
98-PDC-338 . filed August , 1999, entitled "Circuit Interrupter with Trip Bar
Assembly Having Improved Bissing", issued ; US Patent
Application Serisl No, / , Eaton Docket No. 98-PDC-594, filed August
, 1999, entitled "Circuit Interrupter with Improved Din Rail Mounting Adaptor",
issued ; U.S. Patent Application Serisl No. / , Eaton
Docket No. 99-PDC-Q06, fited August _, 1999, entitled "Circuit Interrupter with
Screw Retainmenf, issued ; U.S. Patent Application Serisl No.
/ , Eaton Docket No. 99-PDC-030. filed August , 1999, entitled
"Circuit Interrupter with Crossbar Having Improved Barrier Protection", issued
; U.S. Patent Application Serisl No. / , Eaton Docket No.
99-PDC-054, filed August , 1999, entitled "Circuit Interrupter with Improved
Terminal Shield and Shield Cover", issued ; US. Pater* Application
Serisl No. _/ , Eaton Docket No. 99-PDC-055, filed August 19S9,
entitled "Circuit Interrupter with Versatile Mounting Holes", issued ;
U.S. Patent Application Serisl No. __J . Eaton Docket No. 99-PQC-056,
filed August , 1999, entitled "Circuit interrupter Having Base with Outer Waii
Support", issued ; U.S. Patent Application Serisl No. / ,
Eaton Docket No. 99-POC-094, filed August 1999, entitled •'Molded Case
Circuit Breaker With Current Flow Indicating Handle Mechanism", issued
; U.S. Patent Application Senal No. ___/ , Eaton Docket No.
99-PDC-172. filed August . 1996, entitled "Circuit intemipier with Trip Bas
Assembly Accommodating Internal Space Constraints", issued ;
U.S. Patent Application Serisl No. ___/ . Eaton Docket No. 99-PDC-175.

filed August , 1999. entitled "Circuit Interrupter with Accessory Trip Interface
and Break-Away Access Thereto", issued ; US Patent Application
Serisl No. __/ , Eaton Docket No. 99-POC-176, hed August __. 1999.
entitled "Circuit Interrupter with Break-Away Walking Beam Access", issued
; and U.S. Patent Application Serisl No. / . Eaton Docket
No. 9S-PDC-248, filed August , 1999, ent'^ed "Circuit Breaker W»h Two Piece
Bell Accessory Lever With Overtravef". issued .
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
Ay
The present invention relates to circuit interrupters generally and, more
specrftcafly, to those kinds of circuit interrupters having a base into which a load
terminal inserts.
DESCRIPTION OF THE PRIOR ART
Molded case circuit breakers and interrupters are well known in the art as
exemplified by U.S. Patent No. 4.503.408 issued March 5,1986. to Mrenna et
al, and U.S. Patent 5,910.750 issued June 8.1999 to Malingowski et at... each
of which is assigned to the assignee of the present application and incorporated
herein by reference.
A continuing industry objective with respect to many types of circuit
interrupters is to be able to reduce the size and/or footprint of the interrupter
housing while at the same time providing the same or improved performance
capabilities. A major advantage of creatine) such a "smaller package" is that it
provides increased flexibility in installation. However, a consequence of this
objective is that the internal space constraints of such interrupters have become
much more limiting, posing certain design obstacles that need to be overcome.
The housing of a circuit interrupter typically includes a base into which a
load terminal is situated. The load terminal is partislly accessible from the
outside of the interrupter in order to connect external conductors thereto. The

load terminal is also connected to internal components of the interrupter, such
as the trip mechanism and operating mechanism.
During circuit interrupter use, it has been noted that a load terminal can
sometimes move from its assembled position in the interrupter. In particular, it
has been noted that a load terminal sometimes has a tendency to rise vertically
from its position within the base. Such movement of the load terminal is
undesirable, and can lead to calibration errors.
The prior art has attempted to provide solutions whereby movement of the
load terminal would be prevented. However, such solutions typically are
relatively complicated in design and difficult to implement because of varisbility
in interrupter components. In addition, such solutions frequently occupy valuable
internal space within the interrupter, making them difficult to employ in circuit
interrupters having the aforementioned space constraints.
Therefore, it would be advantageous if a way existed whereby a load
terminal could be effectively and conveniently secured to the base of a circuit
interrupter. It would also be advantageous if such securement could be
effectively employed in a circuit interrupter having the aforementioned internal
space constraints.
Further attention is drawn to DE 11 719 75 B, which discloses an arrangement for
mounting a flat switch piece, without using screws, in an opening of a part of a wall.
A resilient element is adapted to hold said switch piece in a narrow portion of said
hole.
In accordance with the present invention, a circuit interrupter as set forth in claim 1
is provided. Preferred embodiments of the invention are disclosed in the dependent
claims.

The present invention provides a circuit interrupter that meets all of the
above-identified needs.
In accordance with the present invention, a circuit interrupter is
provided which includes a housing including an abutment wall, separable
main contacts within the housing, and an operating mechanism within the
housing and interconnected with the separable main contacts. A terminal is
at least partislly disposed within the housing. A locking plate is positionable
between the terminal and the abutment wail for securing the terminal within the
housing.

This and other objects and advantages of the present invention will
become apparent from a reading of the following description of the preferred
embodiment taken in connection with the attached drawings
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 is an orthogonal view of a molded case circuit interrupter
embodying the present invention.
Figure 2 is an exploded view of the base, primary cover, and secondary
cover of the circuit interrupter of Figure 1.
Figure 3 is a side elevationa) view of an internal portion of the circuit
interrupter of Figure 1.
Figure 4 is an orthogonal view of the internal portions of the circuit
interrupter of Figure 1 without the base and covers.
Figure 5 is an orthogonal view of an internal portion of the circuit
interrupter of Figure 1 including the operating mechanism.
Figure 6 to a side elevational, partislly broken away view of the operating
mechanism of the circuit interrupter of Figure 1 with the contacts and the handle
in the OFF disposition.
Figure; 7 is a side elevatiornal, pertielly broken away view of the operating
mechanism with the contacts and the handle in the ON disposition.
Figure 8 is a side elevational, partislly broken away view of the operating
mechanism with the contacts and the handle in the TRIPPED disposition.
Figure 9 a side elevational, pertislly broken away view of the operating
mechanism during a resetting operation.
figure 10 is a side partislly broken away view of the
housing of the circuit interrupter of Figure 1.
Figure 11 is another side elevational, partislly broken away view of the
cam housing.
Figure 12 is an orthogonal view of the crossbar assembly of the circuit
interrupter of Figure 1,

Figure t3A is an orthogonal view of the trip bar assembly of the circuit
interrupter of Figure t.
Figure 138 is another orthogonal view of the trip bar assembly.
Figure 13C is another orthogonal view of the trip bar assembly.
Figure 130 is another orthogonal view of the trip bar assembly.
Figure T3E is another orthogonal view of the trip bar assembly.
Figure f 4 is an orthogonal, partislly broken away view of a portion of the
circuit interrupter of Figure 1 including the trip bar assembly and its biss spring
Figure 15 is an orthogonal view similar to Figure 14 without the biss
spring.
Figure 16 is an orthogonal view similar to Figure 15 with the biss spring.
Figure 17 is an orthogonal view of a latch of the circuit interrupter of
Figure t.
Figure IS is an oxptoded orthogonal view oh sideplate assembly of the
circuit interrupter of Figure t.
Figure 19 is an orthogonal view of the sideplate assembly, trip bar
asaomfaiy, and crossbar assembly of an internal portion of the circuit interrupter
of Figure 1.
Figure 20 is m orthogonal, pamafly broken away view of the trip" bar
assembly and dual purpose trip actuator of the circuit interrupter of Figure 1.
Figure 21A is an orthogonal view of thedual purposemp actuator.
Figure 218 is another orthogonal view of the dual purpose"trip actuator.
Figure 22 is an orthogonal, partislly broken away view of the trip bar
assembly and dual purpose trip actuator of the circuit interrupter of Figure 1
Figure 23A is an orthogonal view of the automatic trip assembly or tne
circuit interrupter of Figure 1.
Figure 238 is another orthapmat view the automatic trip assembly.
Figure 24A is an orthogp attaching strocture of the trip bar
assembly of the circuit interrupter of Figure 1.
Figure 24B is another orthogonal yiew of the attaching structure.
Figure 24C is another view of the attaching structure.

Figure 240 is another orthogonal view of the attaching structure.
Figure 25A is an orthogonal view of an accessory trip lever of the circuit
interrupter of Figure 1.
Figure 25B is another orthogonal view of the accessory trip lever.
Figure 26 is an orthogonal view of the accessory trip lever of Figure 25A
connected to the attaching structure of Figure 24A.
Figure 27A is an orfrogonal view similar fo Figure 26 with the accessory
trip lever fflted.
Figure 27B is an orthogonal view showing the trip bar assembly with
accessory trip levers tilted.
Figure 28 is an orthogonal, partislly broken away view of a groove in the
base of the circuit interrupter of Figure 1.
Figure 29 is an orthogonal view of the primary cover of the circuit
interrupter of Figure 1 showing a break-away region.
Figure 30 is an orthogonal view of the primary cover and base of the
ckcuit interrupter of Figure 1.
Figure 31 * an orthogonal, partisJly broken away view of the break-away
- region of Figure 2ti.
J^gusaJB is an orthogonal parttatfr brolwn away view of the break-away
s^e^Hs^mpve a^vv^vi^^w vvev#
figure 33 is side ehwational view of the baa* and primary cover of the
circuit interrupter of Figure 1 showing the break-away region broken off.
Figure 34 is an orthogonal view of the internal portions of the base of the
circuit interrupter of Figure 1.
Figure 35 is art orthogonal view of break away regions of the cireait
OTtarraptsr or figure i.
Figure 36 is an orthogonal view of the ondawMe of the base of the circuit
interrupter of Figure 1.
Figure 37 is a cross-sectkxisl view taken along the ftne 37-37 of Figure
36 showing cutouts in ttie base.

Figure 38 is an orthogonal view of an internal portion of the circuit
interrupter of Figure 1 showing the positioning of the break-away regions of
Figure 35.
Figure 39 is an orthogonal view of a locking plate of the circuit interrupter
of Figure 1.
Figure 40 is an orthogonal, partislly broken away view of the locking plate
in connection with the base and primary cover of the circuit interrupter of Figure
1.
Figure 41 is an orthogonal, partislly broken away view similar to Figure
40.
Figure 42 is a cross-sectional view taken along the line 42-42 of Figure
36 showing support members of the circuit interrupter of Figure 1.
Figure 43A is an orthogonal, partislly broken away view of a hole and
recessed regions in the primary cover of the circuit interrupter of Figure 1.
Figure 43B is an orthogonal view of a retaining device of the circuit
interrupter of Figure 1.
Figure 43C is a side etevatbnai view of a secondary cover mounting
screw of the circuit interrupter of Figure 1.
Figure 44A is a cross-sectional, partislly broken away view taken along
the line 44-44 of Figure 43A showing the mounting screw and retaining device
with respect to the hole and recessed regions of the primary cover.
Figure- 44B is a cross-sectionai. partisMy broken away view similar to
Figure 44A.
Figure 45 is an exploded orthogonal view of the base and primary cover
of the circuit interrupter of Figure 1 along with a screw retainment plate.
Figure 46 is an orthogonal view of the screw retainment plate.
Figure 47 is an oithogonal, partislly broken away view of the screw
retainment plate positioned within a recessed region of the primary cover of the
circuit interrupter of Figure 1.
Figure 48 is a side elevational view of a mounting screw of the circuit
interrupter of Figure 1.

Figure 49 is a cross-sectional, partislly broken away view taken along tne
line 49-49 of Figure 45 showing the screw retainment plate and the mounting
screw of the circuit interrupter of Figure 1.
Figure 50 is an overhead view of a recessed region of the primary cover
of the circuit interrupter of Figure 1.
Figure 51 is an exploded orthogonaf view of a terminal shield and the
base and primary cover of the circuit interrupter of Figure 1.
Figure 52 is an orthogonal view of the terminal shield.
Figure 53 is an partislly exploded orthogonal view of the terminal shield,
base, primary cover, and secondary cover of the circuit interrupter of Figure 1.
Figure 54 is a partislly exploded orthogonal view of a terminal shield
cover in connection with the terminal shield, base, primary cover, and secondary
cover of the circuit interrupter of Figure 1.
Figure 55A is an orthogonal view of the terminal shield cover.
Figure 55B is another orthogonal view of the terminal shield cover.
Figure 56 is an orthogonal view of the terminal shield cover, terminal
shield, base, primary cover, and secondary cover in a totally assembled state.
Figure 57 is a cross-sectional, partislly broken away view taken along the
line 57-57 of Figure 56 showing a wire seal arrangement.
Figure 58 is an orthogonal view of the circuit interrupter of Figure 1 with
a DIN ran adapter connected thereto.
Figure 59 is an orthogonal View of the DIN rail adapter.
Figure 60 is an orthogonal view of the backplate of the DIN rail adapter
Figure 61 is an orthogonal view of the slider of the DIN rail adapter.
Figure 62 is a cross-sectional, partislly broken away view taken along the
line 62-62 of Figure 59 showing a stop mechanism.
Figure 63 is an orthogonal view of the DIN rail adapter in a locked-open
state.
Figure 64 is an exploded orthogonal view of ttie base and primary cover
of the circuit interrupter of Figure 1 with the sideplates positioned within the
base.

DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and Figures 1 and 2 in particular, shown
is a molded case circuit interrupter or breaker 10'. Circuit breaker 10 includes a / P*'
base 12 mechanically interconnected with a primary cover 14. Disposed on top ^l
of primary cover 14 is an auxilisry or secondary cover 16. When removed,
secondary cover 16 renders some internal portions of the circuit breaker
available for maintenance and the like without requiring disassembly of the entire
circuit breaker. Base 12 includes outside sidewalls 18 and 19, and internal
phase walls 20, 21, and 22. Holes or openings 23A are provided in primary
cover 14 for accepting screws or other attaching devices that enter
corresponding holes or openings 238, in base 12 for fastening primary cover 14
to base 12. Holes or openings 24A are provided in secondary cover 16 for
accepting screws or other attaching devices that enter corresponding holes or
openings 248 in primary cover 14 for fastening secondary cover 16 to primary
cover 14. Holes 27A in secondary cover 16 and corresponding holes 27B in
primary cover 14 are for attachment of external accessories as described below.
Holes 28 are also for attachment of external accessories (only to secondary
cover 16) as described below. Holes 25. which feed through secondary cover
16. primary cover 14, and into base 12 (one side showing holes 25), are
provided for access to electrical terminal areas of circuit breaker 10. Holes 26A,
which feed through secondary cover 16, correspond to holes 26 that feed
through primary cover 14 and base 12, and are provided for attaching the entire
circuit breaker assembly onto a wall, or into a DIN railback panel or a load
center, orthe like. Surfaces 29 and 30 of secondary cover 16 are for placement
of labels onto circuit breaker 10. Primary cover 14 includes cavities 31. 32, and
33 for placement of internal accessories of circuit breaker 10. Secondary cover
16 includes a secondary cover handle opening 36. Primary cover 14 includes
a primary cover handle opening 38. A handle 40 (Figure 1) protrudes through
openings 36 and 38 and is used in a conventional manner to manually open and
close the contacts of circuit breaker 10 and to reset circuit breaker 10 when it is

in a tripped state. Handle 40 may also provide an indication of the status of
circuit breaker 10 whereby the position of handle 40 corresponds with a legend
(not shown) on secondary cover 16 near handle opening 36 which clearly
indicates whether circuit breaker 10 is ON (contacts closed), OFF (contacts
open), or TRIPPED (contacts open due to, tor example, an overcurrent
condition). Secondary cover T6 and primary cover 14 include rectangular
openings 42 and 44, respectivery, through which protrudes a top portion 46
(Figure 1) of a button tor a push-to-trip actuator. Also shown are load conductor
openings 48 in base 12 that shield and protect load terminals 50. Although "(.pes**
circuit breaker 10 is depicted as a tour phase circuit breaker, the present
invention is not limited to four-phase operation.
Referring now to Figure 3v a longitudinal section of a side elevation,
partislly broken away and partislly in phantom, of circuit breaker 10 is shown
having a load terminai 50 and a line terminal 5Z There is shown a plasma
arc acceleration chamber 54 comprising a slot motor assembly 56 and an arc
extinguisher assembly 58. Also shown is a contact assembly 60. an
mechanism §2, and atrip mechanism 64. Although not viewable in
Figure 3, each phase of circuit breaker 10 has to own load terminal 50. iine
terminal 52, plasma arc acceleration chamber 54. slot motor assembly 56, arc
extinguisher assembly 58, and contact assembly 60, as shown and described
below. Reference is often made herein to only one such group of
components and their constituents tor the sake of simplicity.
Retorting again to Figure 3, and now also to Figure 4 which shows a
side elevational view of the internal workings of circuit breaker 10 without
base 12 and covers 14 and 16, each slot motor assembly 56 is shown as
including a separate upper slot motor assembly 56A and a separate lower slot
motor assembly 56B. Upper slot motor assembly 56A includes an upper slot
motor assembly housing 66 within which are stacked side-by-side U-shaped
upper slot motor assembly plates 68. Similarly, lower slot motor assembly
56B includes a tower slot motor assembly housing 70 within which are
stacked side-by-side lower slot motor assembly plates 72. Plates 68 and 72

are both composed of magnetic materisl.
Each arc extinguisher assembly 58 includes an arc chute 74 within
which are positioned spaced-apart generally parallel angularly offset arc
chute plates 76 and an upper arc runner 76A. As known to one of ordinary
skill in the art the function of arc extinguisher assembly 68 is to receive and
dissipate electrical arcs that are created upon separation of the contacts of
the circuit breaker.
Referring now to Figure 5, shown is an orthogonal view of an internal
portion of circuit breaker 10. Each contact assembly 60 (Figure 3) is shown as
comprising a movable contact arm 78 supporting thereon a movable contact 80,
and a stationary contact arm 82 supporting thereon a stationary contact 84.
Each stationary contact arm 82 is electrically connected to a line terminal 52
and. although not shown, each movable contact arm 78 is electrically connected
to a toad terminal 50. Also shown is a crossbar assembly 86 which traverses the
width of circuit breaker 10 and is rotatably disposed on an internal portion of
base 12 (not shown). Actuation of operating mechanism 62, in a manner
described in detail below, causes crossbar assembly 86 and movable contact
arms 78 to rotate into or out of a disposition which places movable contacts 80
into or out of a disposition of electrical continuity with fixed contacts 84.
Crossbar assembly 86 includes a movable contact cam housing 88 for each
movable contact arm 78. A pivot pin 90 is disposed