Information
-
Patent Grant
-
6207919
-
Patent Number
6,207,919
-
Date Filed
Tuesday, December 7, 199924 years ago
-
Date Issued
Tuesday, March 27, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 218 7
- 218 12
- 218 13
- 218 14
- 218 67
- 218 84
- 218 78
- 218 89
-
International Classifications
-
Abstract
A load break interrupter includes a case, an arc-suppressing tube mounted on and projecting outwardly from the case, a shunt circuit rod slidably supported in the tube with the rod and tube having electrical contacts mounted thereto and convertible between make and break conditions upon sliding of the rod into and from the tube, and a shunt circuit break actuating mechanism disposed in the case and coupled with a leading end of the rod extending into the case such that upon tripping of the actuating mechanism from a shunt circuit-defining position to a shunt circuit-breaking position the rod is pulled partially into the case from the tube thereby breaking the shunt circuit through the rod and between the electrical contacts such that any arcing that occurs upon breaking of the shunt circuit is confined and suppressed inside the tube. The interrupter also includes a reset spring coupled between the case and actuating mechanism and adapted to return the actuating mechanism to the shunt circuit-defining position after each tripping thereof. The case is split diagonally and has a housing to which the arc-suppressing tube is attached and a cover adapted to attach to and form a closed interior chamber with the housing in which the actuating mechanism is disposed. The housing and cover have elements which extend into the interior chamber and cooperate together to mount and retain the actuating mechanism and reset spring and to guide movement of the shunt circuit rod. The tube includes an outer protective sleeve and an inner quench liner mechanically interlocked with the outer sleeve and a vented muffler assembly is mounted on a terminal end of the tube.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
The following copending applications assigned to the same assignee as this application disclose related subject matter:
(1) Ser. No. 09/454,575, filed Dec. 7, 1999, entitled “Load Break Interrupter Having Diagonally Split Case With Component Mounting Elements” by Brad W. Davis.
(2) Ser. No. 09/454,574, filed Dec. 7, 1999, entitled “Load Break Interrupter Having Arc-Suppressing Tube With Mechanically Interlocked Inner Quench Liner” by Brad W. Davis.
(3) Ser. No. 09/454,573, filed Dec. 7, 1999, entitled “Load Break Interrupter Having Vented Muffler Assembly On Arc-Suppressing Tube” by Brad W. Davis.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a load break interrupter for suppressing arcing during opening of a blade-type disconnect switch and, more particularly, is concerned with such an interrupter having a shunt circuit break actuating mechanism.
2. Description of the Prior Art
In the use of high voltage electrical transmission and distribution equipment, it is common practice to provide manually operable blade-type switches which can be opened as needed to break the flow of current in order that linemen can work on such equipment. These switches employ a pivotally movable blade-like contact electrically connected between a pair of fixed switch terminal contacts. When the movable contact of the switch is swung open by means of a conventional hot-line tool or the like, the circuit between the fixed terminal contacts is broken and the flow of current is interrupted. The fixed and movable contacts are in proximal relationship during opening and closing of the movable contact and the swinging movement of the movable contact away from the fixed contacts is slow relative to the current flow.
Because transmission and distribution lines carrying high voltages on the order of 15,000 volts or more will produce arcing which is damaging to the blade-type switch as the movable contact is swung away from the fixed contacts, it is also common practice to employ load break interrupters with such blade-type switches. One load break interrupter marketed under the trademark DuoGap by Hubbell Power Systems, Inc. of Centralia, Mo., a subsidiary of Hubbell Incorporated, is designed to overcome the problems associated with arcing across switch contacts. The Hubbell DuoGap interrupter is illustrated and described in detail in U.S. Pat. No. 4,013,852 to Roberts et al. The Hubbell DuoGap interrupter basically includes a case, an arc-suppressing tube supported on the housing, a reciprocal shunt circuit rod slidably supported in the tube, electrical contacts spaced apart from one another on the rod and tube, and a spring-loaded trip mechanism disposed in the housing and coupled with the rod. Actuation of the trip mechanism pushes the rod through and relative to the tube to break an electrical shunt circuit between the electrical contacts on the rod and on the tube after the movable contact of the blade-type switch has separated from the fixed contacts thereof. Any arcing between the spaced apart electrical contacts on the interrupter rod and tube is confined to and suppressed inside the tube due to the presence of arc-suppressing material therein. The interrupter also includes a mechanism for resetting the interrupter to re-establish the shunt circuit through the interrupter after each actuation thereof.
The above-described Hubbell interrupter has performed highly satisfactorily over a prolonged period of commercial use. However, as with any successful product, the need arises from time to time to make improvements which will enhance its overall manufacture and operation.
SUMMARY OF THE INVENTION
The present invention provides a load break interrupter incorporating improved features that satisfies the aforementioned need. These features are a diagonally split case having component mounting elements, a shunt circuit break actuating mechanism, an arc-suppressing tube having a mechanically interlocked inner quench liner, and a vented muffler assembly on the arc-suppressing tube. One of these features, the shunt circuit break actuating mechanism, constitutes the present invention of this application. This feature along with the other features constituting the inventions of the applications cross-referenced above increase reliability of the interrupter and simplify the manner of assembly and reduce the cost of the interrupter.
Accordingly, the present invention is directed to a load break interrupter which comprises: (a) a case defining an interior chamber; (b) an arc-suppressing tube supported on and extending outwardly from the case; (c) a shunt circuit rod slidably supported in the tube for making and breaking a shunt circuit upon sliding of the rod into and from the tube; (d) a shunt circuit break actuating mechanism disposed in the interior chamber of the case and coupled with the rod such that tripping of the actuating mechanism from a shunt circuit-defining position to a shunt circuit-breaking position pulls the rod at least partially into the case from the tube thereby breaking the shunt circuit such that any arcing that occurs upon breaking of the shunt circuit is confined and suppressed inside the tube; and (e) a reset spring coupled between the case and shunt circuit break actuating mechanism and being adapted to return the actuating mechanism to the shunt circuit-defining position from the shunt circuit-breaking position such that the actuating mechanism pushes the rod from the case back into the tube thereby remaking the shunt circuit.
These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following detailed description, reference will be made to the attached drawings in which:
FIG. 1
is a plan view of a load break interrupter having the improvements constituting the present invention and the inventions of the applications cross-referenced above, with an external lever shown mounted on a housing of a case of the interrupter and adapted to be pivoted by a switch blade or contact of an external blade-type switch as described in the background hereinbefore.
FIG. 2
is a side elevational view of the interrupter as seen along line
2
—
2
of FIG.
1
.
FIG. 3
is another plan view of the interrupter similar to that shown in
FIG. 1
now showing the external lever mounted on a cover of the case of the interrupter.
FIG. 4
is a side elevational view of the interrupter as seen along line
4
—
4
of FIG.
3
.
FIG. 5
is a plan view similar to that of
FIG. 1
but with the cover of the case removed showing a shunt circuit break actuating mechanism disposed within the housing of the case.
FIG. 6
is a longitudinal sectional view of the interrupter taken along line
6
—
6
of FIG.
5
.
FIG. 7
is a plan view similar to that of
FIG. 5
but with the actuating mechanism removed from the housing of the case.
FIG. 8
is an end view of the housing of the case as seen along line
8
—
8
of FIG.
7
.
FIG. 9
is a fragmentary cross-sectional view taken along line
9
—
9
of
FIG. 7
showing a spring anchor post formed on the housing about which is hooked an end of a reset spring employed by the interrupter.
FIG. 10
is a fragmentary cross-sectional view taken along line
10
—
10
of
FIG. 7
showing a collar formed on the housing defining a hole for receiving and mounting a rotatable shaft of the actuating mechanism.
FIG. 11
is an enlarged plan view of the cover of the interrupter case.
FIG. 12
is a cross-sectional view of the cover taken along line
12
—
12
of FIG.
11
.
FIG. 13
is an enlarged side elevational view of a latch of the interrupter actuating mechanism.
FIG. 14
is an end elevational view of the latch as seen along line
14
—
14
of FIG.
13
.
FIG. 15
is an enlarged side elevational view of a drive assembly of the interrupter actuating mechanism.
FIG. 16
is an end elevational view of the drive assembly as seen along line
16
—
16
of FIG.
15
.
FIG. 17
is an enlarged plan view of a latch backup spring of the interrupter actuating mechanism.
FIG. 18
is a side elevational view of the latch backup spring as seen along line
18
—
18
of FIG.
17
.
FIG. 19
is an enlarged plan view of a lever of the interrupter actuating mechanism.
FIG. 20
is a side elevational view of the lever as seen along line
20
—
20
of FIG.
19
.
FIG. 21
is a longitudinal sectional view of a drive shaft of the drive assembly of FIG.
15
.
FIG. 22
is an end elevational view of the drive shaft as seen along line
22
—
22
of FIG.
21
.
FIG. 23
is an opposite end elevational view of the drive shaft as seen along line
23
—
23
of FIG.
21
.
FIG. 24
is an enlarged side elevational view of a shunt circuit rod of the interrupter.
FIG. 25
is an end elevational view as seen along line
25
—
25
of
FIG. 24
showing a connector on a shunt cable attached to a leading end of the shunt circuit rod.
FIG. 26
is an enlarged end elevational view of an arc quench liner of the arc suppressing tube of the interrupter.
FIG. 27
is a longitudinal sectional view of the liner taken along line
27
—
27
of FIG.
26
.
FIG. 28
is a plan view the same as that of
FIG. 5
, showing the interrupter in its relaxed shunt-circuit defining position, the external lever being shown in a rest position before being engaged by a movable switch blade contact of a blade-type switch.
FIG. 29
is a longitudinal sectional view taken along line
29
—
29
of FIG.
28
.
FIG. 30
is a cross-sectional view taken along line
30
—
30
of FIG.
28
.
FIG. 31
is a plan view similar to that of
FIG. 28
, now showing the interrupter in its loaded shunt-circuit defining position prior to tripping of the actuating mechanism of the interrupter, the external lever being shown in a partially displaced position after being engaged and moved relative to the interrupter by the movement of the movable switch blade contact of the blade-type switch out of electrical connection with the fixed contacts of the switch.
FIG. 32
is a longitudinal sectional view taken along line
32
—
32
of FIG.
31
.
FIG. 33
is a cross-sectional view taken along line
33
—
33
of FIG.
31
.
FIG. 34
is a plan view similar to that of
FIG. 32
, now showing the interrupter in its actuated shunt circuit-breaking position after tripping of the actuating mechanism of the interrupter, the external lever being shown in a fully displaced position after the shunt circuit rod has been pulled into the case from the arc-suppressing tube.
FIG. 35
is a longitudinal sectional view taken along line
35
—
35
of FIG.
34
.
FIG. 36
is a cross-sectional view taken along line
36
—
36
of FIG.
34
.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings. Also in the following description, it is to be understood that such terms as “forward”, “rearward”, “left”, “right”, “upwardly”, “downwardly”, and the like are words of convenience and are not to be construed as limiting terms.
Load Break Interrupter—In General
Referring to the drawings and particularly to
FIGS. 1
to
6
, there is illustrated a load break interrupter, generally designated
10
, incorporating several improved features. These improved features are a diagonally split case with component mounting elements, a shunt circuit break actuating mechanism, an arc-suppressing tube having a mechanically interlocked inner quench liner, and a vented muffler assembly on the arc-suppressing tube. Only one of these features, the shunt circuit break actuating mechanism, is the subject of the present invention. However, all such features are described hereinafter to facilitate an overall understanding of the interrupter
10
.
The load break interrupter
10
basically includes a case
12
, an arc-suppressing tube
14
, a shunt circuit rod
16
, a shunt circuit break actuating mechanism
18
and a reset element
20
. The tube
14
is mounted on and projects outwardly from the case
12
. The shunt circuit rod
16
is slidably supported in the tube
14
with the tube
14
and rod
16
having respective electrical contacts
22
,
24
attached thereto and convertible between make and break conditions upon sliding of the rod
16
into and from the tube
14
. The shunt circuit break actuating mechanism
18
is disposed in the case
12
and coupled with a leading end
16
A of the rod
16
which extends into the case
12
such that upon tripping the actuating mechanism
18
from a shunt circuit-defining position (
FIG. 28
) to a shunt circuit-breaking position (
FIG. 34
) the rod
16
is pulled partially into the case
12
from the tube
14
thereby breaking a shunt circuit through the rod
16
and between the electrical contacts
22
,
24
on the tube
14
and rod
16
with any arcing that occurs upon breaking the shunt circuit at the contacts
22
,
24
being confined and suppressed inside the tube
14
. The reset element
20
coupled between the case
12
and the actuating mechanism
18
is adapted to return the actuating mechanism
18
to the shunt circuit-defining position (
FIG. 28
) after each tripping thereof to the shunt circuit-breaking position (FIG.
34
).
Diagonally Split Case With Component Mounting Elements
Referring to
FIGS. 1
to
12
, the case
12
of the interrupter
10
is split diagonally and includes a housing
26
to which the arc-suppressing tube
14
is attached and a cover
28
adapted to attach to and forms a closed interior chamber
30
with the housing
26
in which the shunt circuit break actuating mechanism
18
is disposed. The housing
26
has a generally flat main wall
32
and a side wall
34
integrally attached to, projecting transversely outwardly from, and encompassing the periphery of the main wall
32
. The side wall
34
of the housing
26
has a first end portion
34
A located adjacent to and preferably integrally connected to the tube
14
and an opposite second end portion
34
B located remote from the tube
14
. As can be seen in
FIG. 2
, the first end portion
34
A is greater in height from the main wall than the second end portion
34
B such that opposite side portions
34
C extending between and interconnecting the first and second end portions
34
A,
34
B taper from the first end portion
34
A to the second end portion
34
B.
The cover
28
has a generally flat main wall
36
and a side wall
38
integrally attached to, projecting transversely outwardly from, and encompassing the periphery of the main wall
36
. The side wall
38
of the cover
28
has a first end portion
38
A located adjacent to the tube
14
and the first end portion
34
A of the housing
26
and an opposite second end portion
38
B located remote from the tube
14
and adjacent to the second end portion
34
B of the housing
26
. As can be seen in
FIG. 2
, the first end portion
38
A of the cover side wall
38
is smaller in height from the main wall
36
thereof than the second end portion
38
B thereof such that opposite side portions
38
C of the cover
38
extending between and interconnecting the first and second end portions
38
A,
38
B taper from the second end portion
38
B to the first end portion
38
A. Furthermore, the first end portion
38
A of the side wall
38
of the cover
28
is smaller in height than the first end portion
34
A of the side wall
34
of the housing
26
whereas the second end portion
38
B of the side wall
38
of the cover
28
is larger in height than the second end portion
34
B of the side wall
34
of the housing
26
.
The actuating mechanism
18
is disposed in the interior chamber
30
of the case
12
formed by the housing
26
and cover
28
. The housing
26
and cover
28
have respective elements formed thereon and extending into the interior chamber
30
which cooperate together to mount and retain the components of the actuating mechanism
18
and the reset element
20
and to guide movement of the shunt circuit rod
16
into and from the interior chamber
30
of the case
12
. As best seen in
FIG. 7
, the elements formed on the main wall
32
of the housing
26
which mount the components of the actuating mechanism
18
include an annular collar
40
extending in opposite directions from the main wall
32
of the housing
26
and defining a hole
42
therethrough, posts
44
spaced in one direction from the annular collar
40
, and a first boss
46
disposed between and spaced from the annular collar
40
and the posts
44
. The element formed on the main wall
32
of the housing
26
which mounts the reset element
20
is a second boss
48
spaced in the opposite direction from the annular collar
40
. As best seen in
FIG. 7
, the elements formed on the main wall
36
of the cover
28
which retain the components of the actuating mechanism
18
mounted on their respective housing elements are an annular bearing
50
aligned with and disposed adjacent to the annular collar
40
on the housing
26
, a first protuberance
52
aligned with and disposed adjacent to the posts
44
on the housing
26
, and a second protuberance
54
aligned with the reset element
20
and disposed adjacent to but offset from the second boss
48
on the housing
26
. The elements formed on the main walls
32
,
36
of the housing
26
and cover
28
which guide movement of the rod
16
are two pairs of laterally-spaced apart generally parallel rails
56
,
58
aligned with and extending toward one another. The pair of rails
56
on the main wall
32
of the housing
26
at their first ends
56
A are interconnected by an arcuate-shaped bight
60
disposed adjacent to the first end portion
34
A of the side wall
34
of the housing
26
. The pair of rails
56
at their second ends
56
B together with the second end portion
34
B of the side wall
34
of the housing
26
form a pocket
62
disposed adjacent to the second end portion
34
B of the side wall
34
of the housing
26
. A resilient impact bumper
63
(see
FIG. 6
) is disposed in the pocket
62
at the second ends
56
B of the rails for receiving the impact of the leading end
16
A of the rod
16
when pulled into the case
12
by tripping of the actuating mechanism
18
.
The pair of rails
58
on the main wall
36
of the cover
28
at their first ends
58
A are interconnected by an arcuate bight
64
disposed adjacent to the first end portion
38
A of the side wall
38
of the cover
28
. The pair of rails
58
at their second ends
58
B are spaced apart from one another and disposed adjacent to the second end portion
38
B of the side wall
38
of the cover
28
.
The outer edges of the side walls
34
,
38
of the housing
26
and cover
28
define respective annular rims
34
D,
38
D where they mate with one another. The housing
26
has a plurality of bosses
66
spaced apart from one another and formed on and protruding outwardly from its annular rim
34
D. The cover
28
has a like plurality of lugs
68
spaced apart from one another and formed on and protruding outwardly from its annular rim
38
D and aligned over the bosses
66
of the housing
26
when the cover
28
is mated on the housing
26
. A plurality of fasteners
70
, such as screws, are inserted through openings
72
in the cover lugs
68
and threaded into holes
74
in the housing bosses
66
to securely attach the cover
28
to the housing
26
. Also, an annular gasket
76
is provided between the mated rims
34
D,
38
D so as to provide a seal therebetween.
The housing
26
and cover
28
of the case
12
, including the above-described respective elements thereof, and the tube
14
are preferably made of a suitable plastic material and fabricated by a suitable conventional injection molding process. The housing
26
and tube
14
are molded as a single unit and the cover
28
is molded as a separate unit removably securable to the housing
26
by means of the fasteners
70
as described above.
Shunt Circuit Break Actuating Mechanism
Referring to
FIGS. 5
to
24
, the shunt circuit break actuating mechanism
18
of the interrupter
10
includes a drive shaft
78
, a trip lever
80
, an elongated link
82
, a power spring
84
, a latch
86
and a latch backup spring
88
. The drive shaft
78
is rotatably supported between the annular collar
40
on the housing
26
and the annular bearing
50
on the cover
28
with an end
78
A of the drive shaft
78
extending through the hole
42
where the external lever L is fixedly attached to the shaft
78
. The trip lever
80
is fixedly attached on the drive shaft
78
and has first and second ends
80
A,
80
B extending in opposite directions therefrom. A shunt cable
89
is attached to and extends between the trip lever
80
and the leading end
16
A of the rod
16
so as to provide the portion of the shunt circuit extending between the external lever L and the rod
16
. The elongated link
82
at a first end
82
A is rotatable journalled on the drive shaft
78
between the annular bearing
50
and trip lever
80
and at an opposite second end
82
B has a slot
90
where it is slidably coupled to the leading end
16
A of the shunt circuit rod
16
by a pin
92
. The power spring
84
extends between and resiliently yieldably interconnects the first end
80
A of the trip lever
80
and an intermediate location on the link
82
through an aperture
94
spaced from its first and second ends
82
A,
82
B. The latch
86
is pivotally mounted to the housing
26
by the first boss
46
thereon and disposed adjacent to the first end
82
A of the link
82
where a pin
96
spaced a short distance from the first end
82
A protrudes from the link
82
and extends into a notch
98
formed in a side of the latch
86
. The latch backup spring
88
is mounted at one end between the posts
44
formed on the housing
26
and retained in such mounted position by the first protuberance
52
formed on the cover
28
extending toward the posts
44
. The latch backup spring
88
can be a leaf spring which engages the latch
86
on a side thereof opposite from the notch
98
in the latch
86
which receives the pin
96
protruding from the side of the link
82
adjacent to the latch
86
. The latch backup spring
88
biases the latch
86
toward the pin
96
such that the link
82
is retained by the latch
86
in the relaxed shunt circuit defining position of the actuating mechanism
18
, as seen in FIG.
28
.
The drive shaft
78
and trip lever
80
therewith are rotated counterclockwise from the relaxed shunt circuit defining position shown in
FIG. 28
by counterclockwise movement of the external lever L and in response thereto the power spring
84
is expanded until the drive shaft
78
and trip lever
80
therewith reach a loaded shunt circuit defining position of the actuating mechanism
18
, as seen in FIG.
31
. As the drive shaft
78
and trip lever
80
therewith rotate past the loaded shunt circuit defining position of
FIG. 31
with continued rotation of the external lever L, the second end
80
B of the trip lever
80
engages a free end
86
A of the latch
86
located adjacent to the notch
98
and lifts the latch
86
away from the pin
96
releasing the link
82
and thereby tripping the actuation mechanism
18
allowing it to move abruptly to its shunt circuit breaking position, as seen in FIG.
34
. The released link
82
is now free to rotate abruptly in response to a force imposed thereon by the expanded power spring
84
. Due to the imposed force of the expanded power spring
84
, the link
82
abruptly rotates about the drive shaft
78
and pulls the shunt circuit rod
16
into the interior chamber
30
of the case
12
partially from the tube
14
breaking the shunt circuit.
The reset spring
20
at one end
20
A is hooked about the second boss
48
formed on the housing
26
and at an opposite end
20
B is hooked to the second end
80
B of the trip lever
80
on the drive shaft
78
. As the trip lever
80
is rotated counterclockwise with the drive shaft
78
in response to the external lever L, the reset spring
20
expands and imposes a return force on the trip lever
80
. Then, once the external switch blade (not shown) is completely open and the actuating mechanism
18
has tripped as described above, in response to the external lever L disengaging from the external switch blade the expanded reset spring
20
causes reverse or clockwise rotation of the drive shaft
78
and trip lever
80
and link
82
therewith which brings the pin
96
on the link
82
into engagement with the latch
86
, lifting the latch
86
against its backup spring
88
until the pin
96
is again received in the notch
98
in the latch
86
. At this point the actuating mechanism
18
has returned to its relaxed shunt circuit defining position wherein the contacts
22
,
24
on the tube
14
and shunt circuit rod
16
are again in electrical contact with one another. The pin
96
engages and holds the latch
86
and thereby the link
82
at the initial untripped condition wherein the rod
16
is withdrawn from the interior chamber
30
of the case
12
into the tube
14
.
FIGS. 28
to
36
show the respective positions of the actuating mechanism
18
and the shunt circuit rod
16
of the interrupter
10
at three successive stages of its operation.
FIGS. 28
to
30
show a first stage of operation wherein the actuating mechanism
18
is in the relaxed shunt-circuit defining position and the rod
16
is substantially fully disposed in the tube
14
with their contacts
22
,
24
electrically contacting one another in response to the external lever L connected to the actuating mechanism
18
being disposed in a rest position before being engaged by an external switch blade (not shown) upon movement of the latter in a known manner by a linesman in the process of breaking an electrical connection of a known blade-type switch as discussed in the background hereinabove.
FIGS. 31
to
33
show a second stage of operation wherein the actuating mechanism
18
has moved into the loaded shunt-circuit defining position with the rod
16
still fully in the tube
14
and the contacts
22
,
24
of the tube
14
and rod
16
still electrically connected with one another, prior to the actuating mechanism
18
and rod
16
being tripped as described above, in response to the external lever L assuming a partially displaced position due to being engaged and moved by the external switch blade as the latter is moved and breaks electrical connection with the fixed contacts of the blade-type switch so that line current is then fully transferred through the shunt circuit of the interrupter
10
before the electrical connection is broken through the blade-type switch. And
FIGS. 34
to
36
show a third stage of operation wherein the actuating mechanism
18
is moved into the shunt circuit-breaking position, the rod
16
partially pulled from the tube
14
, and the contacts
22
,
24
of the tube
14
and rod
16
disconnected from one another after tripping of the actuating mechanism
18
as described above, in response to the external lever L assuming a fully displaced position due to being further moved by the external switch blade.
Mechanically Interlocked Inner Quench Liner
Referring to
FIGS. 6
,
26
and
27
, the arc-suppressing tube
14
includes an outer protective sleeve
100
and an inner quench liner
102
mechanically interlocked with the outer sleeve
100
. The outer sleeve
100
includes a pair of annular ridges
104
spaced apart from one another and defined on an interior annular surface
100
A of the sleeve
100
so as to project radially inwardly therefrom. The inner liner
102
includes a pair of annular grooves
106
spaced apart from one another, disposed adjacent to opposite ends of the liner
102
and defined in an exterior annular surface
102
A of the liner
102
so as to project radially inwardly therefrom and receive in an interlocking fashion the annular ridges
104
on the sleeve
100
. The inner liner
102
preferably is molded into the outer sleeve
100
and is made of acetal material.
The shunt circuit rod
16
which extends through the tube
14
includes an elongated plunger portion
108
disposed through and inwardly spaced from the liner
102
when the rod
16
is substantially fully withdrawn into the tube
14
and an arc quenching trailing end portion
110
connected to one end of the plunger portion
108
. The trailing end portion
110
is substantially shorter in length than the plunger portion
108
and preferably is made of acetal. The rod
16
has the annular electrical contact
24
surrounding and attached on the plunger portion
108
adjacent to the trailing end portion
110
. The tube
14
has the electrical contact
22
supported therein adjacent to the one end
102
B of the liner
102
and surrounding and electrically contacting the electrical contact
24
on the rod
16
when the rod
16
is substantially fully withdrawn into (or disposed within) the tube
14
.
Vented Muffler Assembly
Referring again to
FIGS. 1
to
6
, the interrupter
10
further includes a vented muffler assembly
112
mounted on a terminal end
14
A of the arc-suppressing tube
14
. The muffler assembly
112
includes a tubular body
114
having opposite inner and outer ends
114
A,
114
B and a central cavity
116
extending between the opposite ends
114
A,
114
B. The tubular body
114
is adapted to slidably fit at its inner end
114
A over the terminal end
14
A of the tube
14
and to be secured thereto by means of screws
118
.
The muffler assembly
112
further includes an end cap
120
and complementary exterior threads
122
on the outer end
114
B of the tubular body
114
and interior threads
124
on the end cap
120
for removably securing the end cap
120
on the outer end
114
B of the tubular body
114
. A disc
126
made of stainless steel material is disposed between the end cap
120
and the outer end
114
B of the tubular body
114
for shielding the end cap
120
from contact with the arc generated gases in the tube
14
.
The muffler assembly
112
still further includes an annular wall
128
and an annular ring
130
attached on the annular wall
128
. The annular wall
128
is disposed inside the tubular body
124
, extending transversely to the tubular body
114
and partially across the central cavity
116
thereof. The annular wall
128
defines an opening
132
through it. The annular ring
130
is spaced from the end cap
120
and attached on the annular wall
128
, surrounding the opening
132
therein and spaced inwardly from the tubular body
114
. The tubular body
114
has spaced side openings
134
defined therein outwardly from the annular ring
130
such that a path for escape of gases from the tube
14
into the muffler assembly
112
proceeds through the cavity
116
of the tubular body
114
, through the opening
132
of the annular wall
128
, past the annular ring
130
and then radially outwardly through the cavity
116
of the tubular body
114
to the side openings
134
therein. Finally, the muffler assembly
112
includes a roll
136
of porous mesh disposed in the cavity
116
between the annular wall
128
and the end cap
120
and surrounding the annular ring
130
such that the escape path of gases also goes through the roll
136
of porous mesh. The porous mesh
136
is preferably a stainless steel material and in the form of a continuous coiled roll. Preferably, the coiled mesh roll
136
is formed by wrapping a length of continuous mesh material onto a non-circular (hex) shaft (not shown) in forming a coiled roll. Since the mesh material retains a spring action due to its memory, when the coiled roll
136
is slide into the muffler
112
, it springs radially outwardly against the inner diameter of the tubular body
114
resulting in a slight separation of the layers of mesh material so as to provide a desired gas flow rate through the porous mesh roll
136
. The muffler assembly
112
having the foregoing construction creates a back pressure providing the proper balance of gas pressure between the muffler cavity
116
and the interior chamber
30
and enhances the life of the inner liner
102
of the tube
14
. The side openings
134
on the tubular body
114
while allowing passage of vented gases substantially prevents entry of water into the tube
14
via the muffler assembly
112
.
It is thought that the present invention and its advantages will be understood from the foregoing description and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely preferred or exemplary embodiment thereof.
Claims
- 1. A load break interrupter, comprising:(a) a case defining an interior chamber; (b) an arc-suppressing tube supported on and extending outwardly from said case; (c) a shunt circuit rod slidably supported in said tube for making and breaking a shunt circuit upon sliding of said rod into and from said tube; (d) a shunt circuit break actuating mechanism disposed in said interior chamber of said case and coupled with a leading end of said rod such that tripping of said actuating mechanism from a shunt circuit-defining position to a shunt circuit-breaking position pulls said rod at least partially into said case from said tube thereby breaking the shunt circuit such that any arcing that occurs upon breaking of said shunt circuit is confined and suppressed inside said tube, said shunt circuit break actuating mechanism including (i) a drive shaft rotatably supported in said interior chamber between opposite sides of said case, p2 (ii) a trip lever fixedly attached on said drive shaft and having opposite first and second ends extending in opposite directions therefrom, (iii) a link at one end rotatable journalled on said drive shaft and at an opposite end being slidably coupled to a leading end of said shunt circuit rod, said link including a pin protruding therefrom adjacent to said one end of said link, and (iv) a power spring extending between and resiliently yieldably interconnecting said first end of said trip lever and an intermediate location on said link spaced from said first and second ends thereof; and (e) a reset spring coupled between said case and shunt circuit break actuating mechanism and being adapted to return said actuating mechanism to said shunt circuit-defining position from said shunt circuit-breaking position such that said actuating mechanism pushes said rod from said case back into said tube thereby remaking the shunt circuit.
- 2. The interrupter as recited in claim 1, wherein said drive shaft has an end which can protrude from said case at either of said opposite sides thereof so as to attach an external lever thereon.
- 3. The interrupter as recited in claim 1, wherein said shunt circuit breaking actuating mechanism further includes a shunt cable attached to and extending between said trip lever and said leading end of said rod.
- 4. The interrupter as recited in claim 1, wherein said shunt circuit break actuating mechanism further includes a latch pivotally mounted to said casing and disposed adjacent to said one end of said link, said latch having a notch defined in a first side thereof receiving said pin protruding from said link.
- 5. The interrupter as recited in claim 4, wherein said shunt circuit break actuating mechanism further includes means engaging said latch on a second side thereof opposite from said notch and biasing said latch toward said pin such that said link and therewith said shunt circuit rod are retained in said shunt circuit defining position of said actuating mechanism even as the drive shaft rotates and expands said power spring.
- 6. The interrupter as recited in claim 5, wherein said second end of said trip lever, as said drive shaft and trip lever therewith are rotated, is adapted to engage said latch and lift said latch off said pin releasing said link and thereby trip said actuation mechanism to move to said shunt circuit breaking position, said released link now free to rotate in response to a force imposed thereon by said expanded power spring and pull said shunt circuit rod at least partially into said interior chamber of said case breaking the shunt circuit.
- 7. The interrupter as recited in claim 6, wherein as said released link rotates pulling said shunt circuit rod said reset spring expands and imposes a return force on said trip lever causing reverse rotation of said drive shaft and said link therewith until said pin on said link is returned into engagement with said latch and lifts said latch against said backup spring until said pin is again received in said notch in said latch and said actuating mechanism is returned to and retained at said shunt circuit defining position with said pin engaging and holding said latch and thereby said link at an initial untripped position and said shunt circuit rod withdrawn into said tube.
- 8. The interrupter as recited in claim 1, wherein said shunt circuit rod and said tube have contact means thereon convertible between make and break conditions upon sliding of said rod into and from said tube by said actuating mechanism.
- 9. The interrupter as recited in claim 1, wherein said case includes a matable housing and cover with respective elements formed thereon which extend into said interior chamber and cooperate together so as to mount components of said shunt circuit break actuating mechanism.
- 10. The interrupter as recited in claim 1, wherein said case includes a matable housing and cover with respective guide elements formed thereon which extend into said interior chamber, are aligned with said tube and cooperate together so as to guide movement of said shunt circuit rod in said interior chamber.
- 11. The interrupter as recited in claim 10, wherein said casing further includes a resilient impact bumper disposed in said interior chamber between said housing and cover at an end of said guide elements located remote from said tube.
- 12. The interrupter as recited in claim 10, wherein said guide elements are two laterally-spaced apart rails formed on each of said cover and housing, said two rails on said cover being aligned with and extending toward said two rails on said housing.
- 13. The interrupter as recited in claim 12, wherein said casing further includes a resilient impact bumper disposed in said interior chamber between said housing and cover at an end of said rails located remote from said tube.
US Referenced Citations (13)