IMPROVED TERMINAL COLLAR
Cross Reference to Related Applications
The subject matter of this invention is related to U.S. application Serial No.
08/864,104 (96-PDC-547) entitled "Circuit Interrupter with Covered Accessory Case,
Adjustable Under Voltage Relay, Self-Retaining Collar and One-Piece Rail
Attachment", filed May 28, 1997 by Malingowski, et al., and assigned to the present
assignee.
Background of the Invention
Field of the Invention
Subject matter of this invention is related to circuit interrupters generally and
more particularly to wire retainer collars.
Description of the Prior Art
Reference is made to U.S. Patent 5,206,789 entitled "Terminal Assembly for A
Circuit Breaker and Similar Apparatus" issued to Barbry on April 27, 1993. The
present invention is an improvement over the teachings of the '789 patent. Electrical
circuit breakers are well know. It is necessary to interconnect external electrical line
and load terminals to the circuit breaker terminals. One way of doing this is by
utilizing a collar arrangement, which provides a solderless way of interconnecting the
external load and line conductors with the main terminals of the circuit breaker.
Basically the collar arrangement consist of electrically conductive material having a
periphery which captures or encloses an overlapping arrangement of the internal
terminal of the circuit breaker and the external line or load conductor as the case
may by. A set screw arrangement is then provided in a threaded opening in the
collar for turning down on the adjacent overlapping conductor and terminal for
holding them in place. One problem with the prior art collar is the tendency for it to
separate at its peripheral joint as the set screw is turned down onto the overlapping
terminal and conductor. Obviously this is undesirable. It would be desirable,
therefor, if a collar for a circuit breaker could be provided which did not easily
separate when the set screw utilized therein was turned down upon the internal
terminal an external conductor which the collar interconnects.
Summary of the Inventions
In accordance with the invention a circuit breaker system including a collar
for interconnecting an electrical conductor with a terminal is taught. The collar
includes a ribbon of inter-joined material for forming a periphery around the
electrical conductor and terminal for securing them together. The first end of the
ribbon has a male interlocking shape in a first plane. A second end of the ribbon
has a complementary female shape in the same plane for accepting the male
interlocking shape. The male interlocking shape and the complementary female
shape cooperate to hold the first and second ends together in the first plane. The
second end of the conductor has a male protrusion in the first plane and has a
complementary female opening for accepting the protrusion in the first plane. The
male protrusion and the complementary opening when joined resist rotational
movement of the second end of the ribbon in the first plane when the periphery is
put in a state of tension.
Brief Description of the Drawings
For a better understanding of the invention, reference may be had to the
preferred embodiment thereof shown in the accompanying drawings in which:
Figure 1 shows an orthogonal view of a prior art load or line terminal collar
for a circuit breaker;
Figure 2 shows an orthogonal view of the collar of Figure 1 disposed upon a
line or load conductor;
Figure 3 shows a different prior art collar then the one shown in Figures 1
and 2;
Figure 4 shows a terminal collar of the kind embodied in the present
invention; and
Figure 5 shows a side elevation partially broken away of a molded case
circuit breaker utilizing the collar arrangement of Figure 4 on both the load and line
terminals. A jismKA^
Detailed Description of the|Drawinqs
Referring now to Figures 1 and 2, a self-retaining prior art collar 400 for a
load or line conductor for a circuit breaker is depicted. The collar 400 is disposed,
as shown in Figure 2, on a line conductor 71 of a circuit interrupter 10. The collar
400 comprises a formed strip of rectangular cross-section, electrically conductive
material, such as copper, folded over four times at 406, 408, 410 and 412 to form a
hollow rectangular sleeve. One end, 414 of the rectangular member includes a
portion of peninsular material 418 bent over at 416 which is fitted or dove-tailed into
fit with an opening 420 of similar shape in the side of the wall defined by the
corners 406 to 408. In a like manner a rectangular protrusion 422 depends
outwardly from the horizontal section of the bent over material emanating from fold
over 406 towards the right. This latter rectangular portion is interlocked with a key
member or opening 424 in the fold region 412. This secure arrangement allows for
a relatively strong collar member formed from a single unitary piece. There is
provided at the top, a threaded opening 426 into which a threaded member (not
shown) may be axially disposed for downward movement into the central enclosure
428 of the collar member 400 for compressing wires or conductors which may be
inserted therein. The collar shown in Figure 1 includes two side mounted
protrusions or trapping members 430A and 430B which transversely protrude into
the central opening 428. There is also included a sprung raised portion 436
peninsularly arranged in the middle of cutout 438. The raised portion 436 is
adapted for fitting into a hole, as will be described later, in the line conductor 71 of
the circuit interrupter 10.
Referring now to Figure 2, the collar 400 is shown in a self-retained
disposition on the line conductor 71. The line conductor 71 fits between the lower
portion 440 of the dowel- like protrusions 430A and 430B which trap the
rectangular cross-section of the line conductor 71 therebetween and between the
inside bottom 446 of the collar 400. The protrusion 436 protrudes upwardly into
the hole 71A in the line terminal 71 thus longitudinally fixing the relationship
between the collar 440 and the conductor 71. The entrapping protrusions 430A
and 430B prevent the vertical movement of the collar 440 relative to the conductor
71 as viewed in Figure 2. Lateral movement is prevented by the location of the
sidewalls shown, for example, at 450 and 452 in Figure 2.
Referring now to Figure 3, another prior art embodiment of a terminal collar
500 is depicted. Terminal collar 500 is made of a continuous ribbon of electrically
conducted material formed into four sides 502, 504, 506 and 508. A line terminal
510 of the circuit breaker is disposed against the inside of the bottom 508 of the
collar and held in place there by nibs 512. A threaded hole 514 is provided on the
top 504 of the collar 500. In the side 502 there is provided a joint 520 which joins
one end of the ribbon of conductive material with the other end of the ribbon of
conductive material. One of the joint members comprises an inverted male T-
shaped portion, composed of a downwardly projecting vertical bar 526 terminated
in a horizontal projecting bar 528. There is also provided in the other end of the
conductive material of the collar 500 a complementary female T-shaped opening
524. Female T-shape 524 comprises a horizontal open space 532 corresponding
to the horizontal bar 528 and a vertical female space 533 corresponding to the
male vertical bar 526. During construction the male T-shaped interlock 522 is fit
periphery into the complementary female shape 524 to form an interlocked joint
520. As a set screw or similar device is threaded downwardly in the direction 536
in the threaded hole 514 to forcefully compress an external conductor (not shown)
downwardly against the top of the line terminal 510 in the central region 537 of the
collar 500, a force 538 of reaction is generated in the opposite direction tending to
separate the joint 520. If the force 536 and its' reactive force 538 is greater then
the metallurgical strength of the joint 520, the joint members comprising the
enclosed parts 544 of the complementary T-shape 524 will begin to rotate
outwardly in opposite directions 546 under the influence of the upward movement
of the T-surface 540 of the male member 522. The narrow regions 544 defining
the female horizontal shape 532 are the weakest parts of the joint 520 and have a
tendency to bend outwardly in the direction 546 and to perhaps even shear off
depending upon the relative strength of the force 538. The separation of the joint
520 depicted in the prior art collar of Figure 3 is of course undesirable. It would be
desirable to provide a collar having the advantages shown in the collar of Figure 3,
but which nevertheless did not separate or disintegrate at the joint 520 as the force
536 is applied to hold the overlapping line terminal 510 and conductors in the
central region 537 thereof.
Referring now is Figure 4, an improved collar embodying the teachings of
the present invention is depicted. In the description described with respect to
Figure 4 those parts of the collar which are similar to those parts shown in Figure 3
are represented by the same reference symbol having an additional identifying
prime (') associated therewith. In this embodiment of the invention there are
number of differences between the collar 500' of Figure 4 and collar 500 of the
prior art Figure 3. One difference lies in the fact that the nibs 512' are constructed
differently, They are punched-in portions of the sidewalls 506' and 502'. In the
embodiment of Figure 4 the line or load conductor 510 is not shown in order that a
protruding, seating blister or bump 560 in the bottom wall 508' may be depicted.
The line conductor 510, if inserted, would be inserted into the central opening 537'
underneath the protruding nibs 512' and the upper side of the bottom portion 508'
of the collar 500' until a complementary hole in the line terminal (not shown)
captures and is seated by the bump 560. Another significant difference may be
found in the female slots 550 provided in the upper portion of the sidewall 502'
adjacent to the vertical bar 526' of the inverted male T 522'. In this embodiment of
the invention, as a set screw or similar device (not shown) is threaded downwardly
in the direction 536 in the manner described previously with respect to Figure 3,
rather than the external portions of the female complementary T-shape 524
rotating outwardly in the direction 546 as with apparatus of Figure 3, the presence
of the female slots 550 working in conjunction with complementary male tabs 552
at the region 556 prevents or minimizes rotation of the outer portions of the lower
side 502' in the direction 546. The joint 520' as constructed is therefore even
stronger than the joint 520 of Figure 3 and appreciable resists destruction of the
joint as a result of the reactive force in the direction 538 due to the turning of a set
screw or downwardly in the direction 536.
Referring now to Figure 5, a circuit interrupter 10, partially cut away to show
the arrangement of a pair of line and load terminal collars 500' for connection with
a line terminal 510 and a load terminal 510A is depicted. The terminal 510 is
disposed on the inside of the collar against the bottom thereof and is maintained
therein by the presence of the nubs 512'. In each case a joint 520' similar to that
shown in Figure 4 is provided. In the embodiment of Figure 5, the joint 520' for the
collar 500' on the left is shown facing outwardly. The same joint is obscured from
view in the collar 500' on the right. As the set screw 602 is turned downwardly
against a conductor inserted into the collar against the upper portion of the load or
line conductor 510 or 510A, the joint 520' is sufficiently strong to reduce destruction
or deterioration thereof under the influence of the force provided by the set screw
602. In order to operate the circuit breaker 10, a handle 604 is provided to open
and close the separable main contacts disposed within the circuit breaker in a
disposition of continuity with the line and load terminals 510 and 510A.
WE CLAIM!
1. A collar (500') for interconnecting one electrical
conductor with another electrical conductor and which comprises
interjoined material (520') forming a periphery around said two
electrical conductors for securing them together, said
interjoined material (520') being interlocked in a first plane
and said collar (500') being adapted to be penetrated in a plane
perpendicular to said first plane for forcing said electrical
conductors against the inside of said collar, said forcing
(536,538) tending to separate said interjoined material (520') at
said interlock by rotating portions (544) of said interlock
(520') in said plane away from each other, said interlock having
a protrusion (552) in said plane which abuts against a portion
(556) of said interlock to resist said rotation (546) of said
portions (544) of said interlock in said plane away from each
other.
2. A collar as claimed in claim 1 and for interconnecting an
electrical conductor with the terminal (510) of an electrical
device, said collar comprising a ribbon (502', 504*, 506', 508')
of interjoined material (520") for forming a periphery around
said electrical conductor and said terminal for securing them
together, a first end of said ribbon having a male interlocking
shape (522') in a first plane, a second end of said ribbon having
a complementary female shape (524') in said first plane for
accepting said male interlocking shape (522*), said male
interlocking shape and said complementary female shape
cooperating to hold said first and second ends together in said
first plane, said second end also having a male protrusion (552)
in said first plane, said first end also having a complementary
female opening (550) for accepting said male protrusion (552) in
said first plane, said male protrusion and said complementary
opening when joined resisting rotational movement (546) of
portions (544) of said second end of said ribbon in said first
plane.
3. A collar as claimed in claim 1 or 2 wherein said collar
(500') is adapted to be penetrated by securing means (602).
4. A collar as claimed in claim 3, wherein the securing
means is a screw means (602) and the protrusion is an ear (550).
5. A collar as claimed in claim 1, 2, 3 or 4 wherein the
interjoined material is electrically conducting.
6. An electrical circuit interrupter (10) comprising
separable main contacts disposed within an insulating case, one
of said separable main contacts being interconnected with a
terminal (510A, 510') which, in turn, is interconnected with an
electrical conductor by means of a collar as claimed in any of
claims 1 to 5.
7. A collar as claimed in claim 1 and substantially as
described herein with particular reference to Figure 4 of the
accompanying drawings.
8. An electrical circuit interrupter as claimed in claim 6
and substantially as described herein with particular reference
to Figure 5 of the accompanying drawings.

A circuit breaker system having load and line terminals
interconnectable with load and line conductors by way of a solderless collar has a
central opening which encloses an overlapping portion of the internal load or line
terminals and the associated load or line conductors. The collar has a set screw in
the top thereof which is turned down on the overlapping terminal and conductor
until a secure connection is made. The collar has a joint, which may be affected by
the setscrew action associated with securing the external conductor with the
internal terminal. The joint is T-shaped and is provided with vertical tabs on one
portion thereof to prevent the weakest portion of the joint from rotating outwardly
under the affects of the securing action and thus jeopardizing the strength of the
joint.