Information
-
Patent Grant
-
6307456
-
Patent Number
6,307,456
-
Date Filed
Friday, December 10, 199924 years ago
-
Date Issued
Tuesday, October 23, 200122 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
- Cantor Colburn LLP
- Horton; Carl B.
-
CPC
-
US Classifications
Field of Search
US
- 335 202
- 174 66
- 174 138 F
- 200 304
- 200 305
-
International Classifications
-
Abstract
An electrically-insulative terminal cover is arranged on the line end of a light industrial-rated circuit breaker to allow a close-fit arrangement between a plurality of such circuit breakers within a common enclosure. The terminal cover is in the form of a top piece and a perpendicular side piece. The top piece comprises a pair of notches for receiving a pair of electrical conductors connecting with a corresponding pair of circuit breaker electrical terminals. The side piece includes a pair of elongated notches adapted for receiving sides of a pair of adjacent circuit breakers. A center side piece between the elongated notches can be press-fit within a combined slot defined by slots in sides of a pair of abutting side walls of adjacent circuit breakers. The top piece provides electric isolation to a top of the electrical terminals while the side piece provides electric isolation to a front of the electrical terminals.
Description
BACKGROUND OF THE INVENTION
This invention relates to a terminal cover for a circuit breaker for preventing electrical crossover between adjoining circuit breaker terminals. In particular, this invention relates to a terminal cover for a light industrial rated circuit breaker that can be installed without the use of fasteners and which does not interfere with adjacent mounting of multiple breakers.
Industrial-rated circuit breakers in excess of 600 volt rating, such as described within U.S. Pat. No. 5,150,091 entitled “Bus Cover and Lug Cover for a Molded Case Circuit Breaker,” are often required to become positioned next to similar circuit breakers within a common enclosure. To prevent electrical crossover between adjoining circuit breaker terminals upon the occurrence of a short circuit over-current condition within adjoining circuit breakers, the circuit breakers must be separated by a sufficient distance for electrical over-surface clearance.
U.S. Pat. Nos. 5,084,689 and 5,049,846, both entitled “Compact Molded Case Circuit Breaker with Increased Ampere Rating,” describe the use of lug cover extensions to the line end of the circuit breakers to protect the line lugs from inter-phasal faults.
The aforementioned U.S. patents describe the use of screws and the like to fixedly attach the separate lug covers to the circuit breaker enclosures at an added expense in materials, time, and labor.
So-called “light industrial-rated circuit breakers,” up to 400 volt rating, are also used within common enclosures and are separated for over-surface clearance. Low costs are achieved by utilizing single pole circuit breakers attached together with a common handle tie for simultaneous ON-OFF operation. Because of the lower costs associated with such light industrial-rated circuit breakers, the added expenses of a lug cover was heretofore unwarranted. The space separation requirement limits the number of circuit breakers used within the enclosure with a resultant limitation in
SUMMARY OF THE INVENTION
Thus, there is a need for a lug or terminal cover to be used with light industrial-rated circuit breakers at a minimum increase in cost to allow several such circuit breakers to be used in adjacent relation within a common enclosure with minimal inter-circuit breaker spacial separation.
In an exemplary embodiment of the invention, an electrically-insulative terminal cover is arranged on the line end of a light industrial-rated circuit breaker to allow a close-fit arrangement between a plurality of such circuit breakers within a common enclosure. The terminal cover is preferably in the form of an integrally formed right-angled piece having a top piece and a perpendicular side piece. The top piece comprises a pair of notches for receiving a pair of electrical conductors connecting with a corresponding pair of circuit breaker electrical terminals. The side piece includes a pair of elongated notches adapted for receiving sides of a pair of adjacent circuit breakers. A center side piece between the elongated notches can be press-fit within a combined slot defined by slots in sides of a pair of abutting side walls of adjacent circuit breakers. The top piece provides electric isolation to a top of the electrical terminals while the side piece provides electric isolation to a front of the electrical terminals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a top perspective view of a circuit breaker terminal cover in accordance with the invention;
FIG. 2
is a front perspective view of the terminal cover of
FIG. 1
in isometric projection with a light industrial-rated circuit breaker prior to attachment therewith; and
FIG. 3
is a front perspective view of the terminal cover attached to the circuit breaker of FIG.
2
.
DETAILED DESCRIPTION OF THE INVENTION
The lug or terminal cover
10
is shown in
FIG. 1
to comprise a right angle piece
12
defining a top piece
14
and a side piece
16
perpendicularly extending down therefrom. The piece
12
comprises an electrically insulative material, and is preferably integrally molded in plastic to form a one piece cover. A first notch
18
and a second notch
20
are formed within the top piece
14
on opposite sides of the center top piece
22
and with first and second end top pieces
24
,
26
at the ends of the top piece
14
thereof. The open-ended notches
18
and
20
may extend from an outside edge of the top piece
14
to a rounded end within the top piece
14
as shown. The notches
18
and
20
are preferably parallel and of equivalent size, and are adapted to at least encompass the diameter of one line conductor extending from a circuit breaker.
A center side piece
28
is formed in the side piece
16
having a first elongated notch
46
on one side and a second elongated notch
48
on the opposite side with first and second end side pieces
30
,
36
formed on the ends of the side piece
16
. The elongated notches
46
and
48
may be open-ended and rounded as described above with respect to notches
18
and
20
. The side piece
16
further comprises a first side
32
on first end side piece
30
and a second side
38
on second end side piece
36
which are indented from sides
42
and
44
of side piece
16
. Preferably the width w
l
, of the side piece
16
is equivalent to the width w
t
, of the top piece
14
where the side piece
16
is adjacent the top piece
14
. Where the side piece
16
is indented, the width w
2
is less than the width w
1
. The resultant indents
34
and
40
preferably correspond in size to a thickness of an exterior wall of a circuit breaker for providing a snug fit with a circuit breaker as will be described.
The terminal cover
10
is shown in
FIG. 2
prior to attaching to the line end of a two pole circuit breaker
50
consisting of a pair of single pole circuit breakers
52
,
54
joined by rivets as indicated at
60
. The load terminals
56
,
58
are located at the bottom of the circuit breaker
50
with the line terminals
62
,
64
at the top of the circuit breaker
50
to indicate the positioning of the terminal cover
10
over the line terminals
62
,
64
. The single pole circuit breakers include a pair of operating handles
66
,
68
interconnected for common response by means of the handle tie
70
and are shown in the ON condition and a pair of line conductors
72
,
74
are connected with the line terminals
62
,
64
. The line conductors
72
,
74
extend through the notches
18
,
20
formed in the top piece
14
with the center top piece
22
intermediate the line conductors
72
,
74
and the end top pieces
24
,
26
capturing the line conductors
72
,
74
within the notches
18
,
20
, respectively.
When terminal cover
10
is attached to breakers
52
,
54
, center side piece
28
, intermediate the elongated notches
46
,
48
, is captured within the combined slots
80
,
82
formed by the slotted or grooved sides
76
,
78
of the single pole circuit breakers
52
,
54
. That is, the slot
80
on side
76
combines with slot
82
on side
78
to form a single slot in which center side piece
28
is preferably snugly captured therewithin to retain the terminal cover
10
on the circuit breaker
50
. Likewise, each notch
46
,
48
is adapted to accept a portion of sides
76
and
78
therewithin. Simultaneously, the sides
32
and
38
are preferably captured within interior sides
84
and
86
of single pole circuit breakers
52
and
54
, respectively.
The terminal cover
10
is shown in
FIG. 3
attached to the two pole circuit breaker
50
with the center side piece
28
of the side piece
16
captured within the slotted sides
76
,
78
of the single pole circuit breakers
52
,
54
. The line terminals
62
,
64
are shielded in the front by means of the end side pieces
30
,
36
and are shielded at the top by means of the end top pieces
24
,
26
and the center top piece
22
intermediate the line conductors
72
,
74
. Thus, the cover
10
may be simply attached to the breaker
50
using a press fit, eliminating the need for fasteners. Of course, a snap fit is also within the scope of this invention. The slotted or notched pieces
14
and
16
allow for easy installation/removal of the cover
10
without removing any wiring. When a pair of such “shielded” two pole circuit breakers
50
are arranged side-by-side within a common enclosure, the terminal covers on both of the shielded circuit breakers contribute to added protection against any arc occurrence within either of the shielded circuit breakers upon the occurrence of a short circuit condition within either of the adjacent circuit breakers. Furthermore, the width w
t
of the terminal cover
10
is preferably equivalent to the width w
c
, of the circuit breaker
50
. With the terminal cover
10
thus designed within the envelope of the circuit breaker
50
, adjacent mounting of multiple breakers is enabled.
A simple terminal lug cover has been shown for attachment to the line end of a two pole circuit breaker by insertion within a combined slot formed within the slotted ends of the component single pole circuit breakers without requiring any additional fasteners.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
Claims
- 1. A terminal cover for a pair of circuit breakers having line terminals, said terminal cover comprising:a substantially planar top piece lying within a first plane, the top piece having a free end and an opposing attached end; a substantially planar side piece lying within a second plane, the side piece having a free end and an opposing attached end, wherein the attached end of the top piece abuts with the attached end of the side piece and the first plane and the second plane intersect at a nonzero angle; a first notch and a second notch formed within said free end of said top piece, said first and second notches adapted for receiving a pair of electrical conductors connecting with a corresponding pair of circuit breaker electrical terminals; a enter top piece within said free end of said top piece and intermediate said notches; a pair of elongated notches formed within said free end of said side piece, said elongated notches adapted for receiving sides of a pair of adjacent circuit breakers; and a center side piece intermediate said elongated notches, said center side piece being adapted for reception in press-fit relation within a combined slot defined by slots in sides of a pair of adjacent circuit breakers; wherein the first and second notches are dimensionally larger than the pair of elongated notches.
- 2. The terminal cover of claim 1 including a pair of end side pieces within said side piece.
- 3. The terminal cover of claim 2 wherein the top piece has a width and the side piece comprises a first width equivalent to the width of the top piece and a second width, defined by a combined width of the pair of end side pieces, the center side piece, and the pair of elongated notches, which is less than the first width.
- 4. The terminal cover of claim 1 wherein said cover is electrically insulative.
- 5. The terminal cover of claim 4 wherein said cover comprises plastic.
- 6. The terminal cover of claim 1 wherein the first and second notches are symmetrically located within the top piece and the pair of elongated notches are symmetrically located within the side piece.
- 7. The terminal cover of claim 6 wherein the first and second notches are parallel to each other and the pair of elongated notches are parallel to each other.
- 8. The terminal cover of claim 1 wherein each of the first and second notches and the pair of elongated notches are open ended on one end and rounded on an opposite end thereof.
- 9. A multi-pole circuit breaker having electrically-isolated line terminals comprising:a first single pole circuit breaker having a first line terminal intermediate a pair of first side wall extensions for connecting with a first line conductor; a second single pole circuit breaker having a second line terminal intermediate a pair of second side wall extensions for connecting with a second line conductor, said first and second circuit breakers being attached to form a multi-pole circuit breaker whereby one of said first side wall extensions abuts one of said second side wall extensions to form an intermediate slot; a terminal cover having a top piece and a downwardly depending side piece; a pair of notches formed within said top piece, said notches adapted for receiving the first and second line conductors; a center top piece intermediate said notches, said center top piece providing electric isolation to a top of said first and second line terminals; a pair of elongated notches formed within said side piece, said elongated notches adapted for receiving side wall extensions of a pair of adjacent circuit breakers; and a center side piece intermediate said pair of elongated notches, said center side piece being adapted for reception in press-fit relation within said intermediate slot.
- 10. The multi-pole circuit breaker of claim 9 further comprising:a first operating handle extending from said first circuit breaker for turning said first circuit breaker between ON and OFF conditions; a second operating handle extending from said second circuit breaker for turning said second circuit breaker between ON and OFF conditions; and a handle tie connecting between first and second operating handles for moving said first and second operating handles in unison.
- 11. The multi-pole circuit breaker of claim 9 wherein the first single pole circuit breaker and the second single pole circuit breaker each have one non-abutting side wall extension, and wherein the side piece of the terminal cover comprises a first end side piece adjacent a first elongated notch and a second end side piece adjacent a second elongated notch, the side piece of the terminal cover further comprising a first indent adjacent the first end side piece and a second indent adjacent the second end side piece, wherein each indent is equivalent in width to a thickness of one non-abutting side wall extension.
- 12. The multi-pole circuit breaker of claim 9 wherein the top piece and the side piece of the terminal cover are perpendicular to each other.
- 13. The multi-pole circuit breaker of claim 9 wherein the side piece of the terminal cover comprises a pair of end side pieces, said end side pieces providing electric isolation to a front of the first and second line terminals.
- 14. The multi-pole circuit breaker of claim 9 wherein the intermediate slot is formed by a combination of a first groove and a second groove, the first groove and second groove located in the abutting first and second side wall extensions, respectively.
- 15. A terminal cover for a pair of circuit breakers having line terminals, said terminal cover comprising:a top piece, the top piece having a width; a side piece depending angularly from the top piece, the side piece including a pair of end side pieces, the side piece comprising a first width equivalent to the width of the top piece; a first notch and a second notch formed within said top piece, said first and second notches adapted for receiving a pair of electrical conductors connecting with a corresponding pair of circuit breaker electrical terminals; a center top piece within said top piece and intermediate said notches; a pair of elongated notches formed within said side piece, said elongated notches adapted for receiving sides of a pair of adjacent circuit breakers; and a center side piece intermediate said elongated notches, said center side piece being adapted for reception in press-fit relation within a combined slot defined by slots in sides of a pair of adjacent circuit breakers; wherein the side piece comprises a second width defined by a combined width of the pair of end side pieces, the center side piece, and the pair of elongated notches, the second width of the side piece being less than the first width of side piece.
- 16. The terminal cover of claim 15 wherein said cover is electrically insulative.
- 17. The terminal cover of claim 15 wherein the first and second notches are symmetrically located within the top piece and the pair of elongated notches are symmetrically located within the side piece.
- 18. The terminal cover of claim 15 wherein first and second notches are parallel to each other and the pair of elongated notches are parallel to each other.
- 19. The terminal cover of claim 15 wherein each of the first and second notches and the pair of elongated notches are open ended on one end and rounded on an opposite end thereof.
- 20. The terminal cover of claim 15 wherein the top piece and the side piece are perpendicular.
- 21. A terminal cover for a pair of circuit breakers having line terminals, said terminal cover comprising:a substantially planar top piece lying within a first plane, the top piece having a free end and an opposing attached end; a substantially planar side piece lying within a second plane, the side piece having a free end and an opposing attached end, wherein the attached end of the top piece abuts with the attached end of the side piece and the top piece and the side piece are perpendicular; a first notch and a second notch formed within said free end of said top piece, said first and second notches adapted for receiving a pair of electrical conductors connecting with a corresponding pair of circuit breaker electrical terminals; a center top piece within said free end of said top piece and intermediate said notches; a pair of elongated notches formed within said free end of said side piece, said elongated notches adapted for receiving sides of a pair of adjacent circuit breakers; and a center side piece intermediate said elongated notches, said center side piece being adapted for reception in press-fit relation within a combined slot defined by slots in sides of a pair of adjacent circuit breakers.
US Referenced Citations (6)