U.S. patent number 3,681,545 [Application Number 05/075,182] was granted by the patent office on 1972-08-01 for drawout switchgear.
This patent grant is currently assigned to Westinghouse Electric Corporation. Invention is credited to Albert R. Cellerini, John Majcher, Charles R. Paton.
United States Patent |
3,681,545 |
Cellerini , et al. |
August 1, 1972 |
DRAWOUT SWITCHGEAR
Abstract
Improved drawout switchgear comprises interlocking means
automatically operable to lock the movable assembly in the
connected position with interlock defeating means operable to
maintain the interlock means in a defeated position while an
operator operates a levering mechanism to lever the movable
assembly from the connected position to a disconnected position.
The interlock means is connected to maintain the trip structure of
the drawout circuit breaker in a tripped condition when the
interlock means is in the defeated or non-interlocking position.
Improved secondary contact means is provided for connecting and
disconnecting control circuits of the switchgear.
Inventors: |
Cellerini; Albert R. (Beaver,
PA), Majcher; John (New Brighton, PA), Paton; Charles
R. (New Brighton, PA) |
Assignee: |
Westinghouse Electric
Corporation (Pittsburgh, PA)
|
Family
ID: |
22124092 |
Appl.
No.: |
05/075,182 |
Filed: |
September 24, 1970 |
Current U.S.
Class: |
200/50.21;
200/254; 200/50.27 |
Current CPC
Class: |
H02B
11/133 (20130101); H01H 9/20 (20130101) |
Current International
Class: |
H02B
11/133 (20060101); H01H 9/20 (20060101); H02B
11/00 (20060101); H01h 009/20 () |
Field of
Search: |
;200/5AA,166E,166D
;339/65,66R,66M |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Ginsburg; M.
Claims
1. Drawout switchgear comprising a stationary assembly and a
movable assembly, said stationary assembly comprising stationary
main terminal means, said movable assembly comprising movable main
terminal means, track means supporting said movable assembly on
said stationary assembly for movement between a first position
wherein said movable main terminal means is connected to said
stationary main terminal means and a second position wherein said
movable main terminal means is disconnected from said stationary
main terminal means,
a levering structure on said stationary and movable assemblies,
said levering structure being manually operable to move said
movable assembly on said track means between said first and second
positions,
interlock means comprising an interlock member movably supported on
said movable assembly, said interlock member being automatically
movable to an interlocking position when said movable assembly is
moved to said first position to lock said movable assembly in said
first position, said interlock member being manually movable to a
non-interlocking position, an interlock defeating member on said
stationary assembly for cooperation with said interlock member,
said interlock defeating member being manually movable to an
interlock defeating position, with said movable assembly in said
first position and said interlock member in said interlocking
position said interlock member being manually movable to the
non-interlocking position and while said interlock member is held
in the non-interlocking position said interlock defeating member
being manually movable to the interlock defeating position to
engage said interlock member and maintain said interlock member in
the non-interlocking position upon release of said interlock member
whereby said interlock member will be maintained in the
non-interlocking position without being manually held in the
non-interlocking position as an operator manually operates said
levering structure to move said movable assembly on said track
means from
2. Drawout switchgear according to claim 1, said stationary
assembly comprising a plate member having a slot therein, said
interlock member on said movable assembly comprising a lock part
and spring biasing means biasing said interlock member toward the
interlocking position, when said movable assembly reaches said
first position said spring biasing means biasing said interlock
member to bias said lock part into locking
3. Drawout switchgear according to claim 2, pivot support means
pivotally supporting said interlock member intermediate the ends of
said interlock member, said lock part being disposed on a first
side of said pivot support means, and said interlock member being
manually engageable on the second side of said pivot support means
opposite said first side and being manually movable about said
pivot support means to the non-interlocking
4. Drawout switchgear according to claim 3, and said interlock
defeating member being pivotally mounted on said stationary
assembly and manually pivotally movable to a position in
interengagement with said interlock member to maintain said
interlock member in the non-interlocking position to enable
movement of said movable assembly from said first position by
5. Drawout switchgear according to claim 4, said levering structure
comprising a pair of levers supported in a spaced relationship on
said stationary assembly and connected for simultaneous movement
about a fixed pivot, said levering structure comprising a crank arm
connected to move said pair of levers, and said movable assembly
comprising a pair of projecting parts engageable by said pair of
levers such that said pair of levers operating against said
projecting parts will drive said movable assembly between said
first and second positions upon operation of said
6. Drawout switchgear according to claim 4, said levering structure
comprising a pair of levers supported on said stationary assembly
in a spaced relationship and connected for simultaneous pivotal
movement, said levering structure comprising a pair of projecting
parts on said movable assembly cooperable with said pair of levers,
and said levering structure comprising a screw type operator on
said stationary assembly rotatable to pivot said pair of levers to
thereby drive said projecting parts to lever
7. Drawout switchgear according to claim 1, said movable assembly
comprising a circuit breaker, said circuit breaker comprising a
pair of contacts and trip means operable to a tripped position to
effect automatic opening of said contacts and to maintain said
contacts in the open position while said trip means is in the
tripped position, and trip actuating means operatively connecting
said interlock member with said trip means such that said trip
means will be in the tripped position when
8. Drawout switchgear comprising a stationary assembly and a
movable assembly, said stationary assembly comprising stationary
main terminal means, said movable assembly comprising movable main
terminal means, track means supporting said movable assembly on
said stationary assembly for movement between a first position
wherein said movable main terminal means is connected to said
stationary main terminal means and a second position wherein said
movable main terminal means is dis-connected from said stationary
main terminal means, a levering structure on said stationary and
movable assemblies manually operable to move said movable assembly
on said track means between said first and said second positions,
interlock means comprising an interlock member movably supported on
said movable assembly and automatically movable to an interlocking
position when said movable assembly is moved to the connected
position to lock said movable assembly in said connected position,
said interlock member being manually movable to a non-interlocking
position to permit movement of said movable assembly from said
first position to said second position,
said switchgear comprising a circuit breaker, said circuit breaker
comprising a pair of contacts and an operating mechanism operable
to open and close said contacts, said circuit breaker comprising a
trip member movable to a tripping position to effect automatic
opening of said contacts, trip actuating means on said movable
assembly, said trip actuating means comprising an elongated member
operatively connected to said interlock member and supported for
generally rectilinear movement, said trip actuating means
comprising an intermediate member, pivot support means pivotally
supporting said intermediate member intermediate the ends of said
intermediate member, means operatively connecting said intermediate
member to said elongated rectilinearly movable member on one side
of said pivot support means, said trip actuating means comprising
actuating means connected to said intermediate member on the other
side of said pivot support means, and upon movement of said
interlock member to said non-interlocking position said elongated
member moving rectilinearly to drive said intermediate member about
said pivot support means to thereby drive said actuating means to a
tripped position during which movement said actuating means
operates said trip member to said tripping
9. Drawout switchgear according to claim 8, said interlock member
being pivotally supported intermediate the ends thereof on said
movable assembly, and lost-motion connecting means connecting said
interlock
10. Drawout switchgear comprising a stationary assembly and a
movable assembly, secondary contact means comprising a stationary
secondary contact structure on said stationary assembly and a
movable secondary contact structure on said movable assembly,
said stationary secondary contact structure comprising a pair of
generally flat stationary insulating boards and support means
supporting said stationary insulating boards in a spaced
relationship, a plurality of pairs of stationary contacts supported
on the opposite sides of said stationary insulating boards,
said movable secondary contact structure comprising a pair of
generally flat movable insulating boards and support means
supporting said movable insulating boards in a spaced relationship,
a plurality of pairs of movable contacts supported on opposite
sides of said movable insulating boards, said support means
comprising a plurality of separate generally U-shaped insulating
supports between said movable insulating boards in a spaced
relationship, upon movement of said movable secondary contact
structure from a disconnected position to a test position each of
said pairs of movable contacts engaging the outer sides of a
separate pair of said stationary contacts and said U-shaped
insulating supports moving between adjacent stationary contacts to
guide said movable contacts into aligned engagement with said
stationary contacts.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention:
Drawout-type switchgear.
2. Description of the Prior Art:
In the patent to Cellerini et al., U.S. Pat. No. 3,343,042 issued
Sept. 19, 1967, there is disclosed drawout switchgear comprising a
movable assembly having a pair of pivotally mounted interlock
members thereon, which interlock members cooperate with slots in a
pair of plate members of the stationary assembly to lock the
movable assembly in the connected position. This invention is an
improvement over the drawout switchgear disclosed in the
above-mentioned Cellerini et al patent in that a pair of interlock
defeating members are pivotally mounted on the stationary assembly
and movable to interlock-defeating positions wherein the interlock
defeating members prop the interlock members away from the slots so
that an operator will have a free hand to operate the levering
mechanism in order to withdraw the movable assembly from the
connected position to a disconnected position.
In the above-mentioned Cellerini et al U.S. Pat. No. 3,343,042, a
trip-actuating assembly, separate from the interlock members, is
provided for operating the circuit breaker to the tripped position
as the circuit breaker is moved from the connected to the
disconnected position and as the circuit breaker is moved toward
the connected position. This invention is an improvement over the
structure disclosed in the Cellerini et al. U.S. Pat. No. 3,343,042
in that an improved trip actuating means is connected to one of the
interlock members to provide that when the one interlock member is
in a non-interlocking position on the stationary assembly the
circuit breaker will be in the tripped condition.
The drawout switchgear of this invention also comprises improved
secondary contact means for connecting and disconnecting control
parts of the switchgear in a circuit.
SUMMARY OF THE INVENTION
Improved drawout switchgear comprises a stationary assembly and a
movable circuit-breaker assembly with track means supporting the
movable assembly on the stationary assembly for movement between a
connected and disconnected position. A levering assembly on the
stationary and movable assembly is manually operable to move the
movable assembly on the track means. A pair of separable interlock
members are pivotally mounted on the movable assembly and spring
biased to move into slots in a pair of side plates of the
stationary assembly when the circuit breaker is in the connected
position to lock the circuit breaker in the connected position. The
interlock members are individually manually movable to
non-interlocking positions, and a pair of interlock-defeating
members on the stationary assembly are individually movable to
defeating positions to maintain the interlock members in
non-interlocking positions to thereby provide that the operator
will have a free hand to manually operate the levering device in
order to move the movable assembly from the connected to a
disconnected or test position. Trip actuating means is connected to
at least one of the interlock members and actuated upon movement of
the one interlock member to the non-interlocking position to trip
the circuit breaker and maintain the circuit breaker in a tripped
condition so long as the interlock member is in the
non-interlocking position. Improved simplified secondary contact
means is provided for connecting and disconnecting control parts of
the switchgear in a circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a switchboard or control center
comprising six compartments housing drawout switchgear constructed
in accordance with principles of this invention;
FIG. 2 is a front view, with parts broken away, of drawout
switchgear housed in one of the compartments of the control center
seen in FIG. 1;
FIG. 3 is a side view of the drawout switchgear seen in FIG. 2;
FIG. 4 is a front view, with parts broken away, of the stationary
assembly of the switchgear seen in FIG. 2;
FIG. 5 is a side view of the assembly illustrated in FIG. 4;
FIG. 6 is a front view of the movable assembly of the drawout
switchgear seen in FIG. 2;
FIG. 7 is a side view of the movable assembly seen in FIG. 6;
FIG. 8 is a front view, with parts broken away, of the carrier
structure of the movable assembly seen in FIG. 6;
FIG. 9 is a side view of the carrier structure seen in FIG. 8;
FIG. 10 is a top plan view of the movable secondary contact
structure seen in FIG. 7;
FIG. 11 is an end view, with parts broken away, of the movable
secondary contact structure seen in FIG. 10;
FIG. 12 is a top plan view of the stationary secondary contact
structure as seen in FIG. 3;
FIG. 13 is a secondary view taken along the line XIII--XIII of FIG.
12;
FIG. 14 is a sectional view of one of the pairs of main disconnect
contacts seen in FIG. 3;
FIG. 15 is a side view similar to FIG. 5 illustrating a modified
form of the invention; and
FIG. 16 is a plan view of the stationary assembly illustrated in
FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, there is shown, in FIG. 1, a control
center or switchboard 5 comprising a cabinet structure 7 having six
compartments therein each of which compartments is provided with a
front opening that is covered by means of an openable door 9. Each
of the doors 9 is provided with a suitable opening therein for
receiving the operating handle of an enclosed circuit breaker when
the door is in the closed position. Within at least one of the
compartments of the switchboard 5 there is housed drawout
switchgear 11 (FIGS. 2 and 3) constructed in accordance with the
principles of this invention.
The drawout switchgear 11 comprises a stationary assembly 13 (FIGS.
2-5) and a movable assembly 15 (FIGS. 2, 3, 6 and 7).
The stationary assembly 13 (FIGS. 4 and 5) comprises a back support
plate structure 17 and a pair of side support plates 19 fixedly
secured to the back support plate structure 17. A pair of tracks 21
(FIG. 4) are fixedly secured to the inner sides of the side plates
19. Each of the side plates 19 is provided with an elongated
opening 23 (FIG. 5) therein. Each of the side plates 19 is also
provided with three slots 25, 27 and 29 in the upper portion
thereof. A levering structure 31 is also supported on the side
plates 19. The levering structure 31 comprises a pair of levers 33
connected together by means of an elongated rod 35 (FIG. 4) and
supported for movement about the axis of the rod 35 on the side
plates 19. The rod 35 extends through suitable openings in the side
plates 19 to support the rod 35 for pivotal movement. Each of the
levers 33 is provided with a slot 37 at the upper end thereof. A
handle arm 39 is fixedly secured to the one lever 33 to enable
manual operation of the levering structure 31. Upon movement of the
handle 39 the levers 33 move unitarily about the axis of the rod
35. The stationary assembly 13 also comprises a pair of interlock
defeating members 41 (FIG. 5). Each of the interlock defeating
members 41 is mounted for pivotal movement on the associated side
plate 19 by means of a separate pin 43, and a separate stop pin 45
is provided on each of the plates 19 to limit movement of the
associated interlock defeating member 41 in one direction. Each of
the interlock defeating members 41 is provided with a depression 47
at the upper end thereof for cooperating within an interlock member
in a manner to be hereinafter described.
The stationary assembly 13 also comprises six stationary main
terminal structure 51 (FIG. 14) and a secondary stationary contact
structure 53 (FIGS. 12 and 13). Each of the stationary main
terminal structures 51 comprises and insulating support member 55
supported on the support structure 17 by means of four bolts 57
only two of which are seen in FIG. 14. A front conductor 59 is
connected to a rear conductor 61 and both are mounted on the
insulating support 55 by means of bolts 63. Each of the conductors
61 is provided with openings 65 therein for receiving bolts which
enable connection of the conductor 61 with a bus bar in the
switchboard.
The stationary secondary contact assembly 53 (FIGS. 12 and 13)
comprises a pair of stiff flat insulating support boards 71 held in
a spaced relationship by means of an elongated insulating spacer
support bar 73 and a second elongated insulating support bar 75. A
plurality of pairs of elongated contacts 77 are supported on the
outer sides of the insulating support boards 71 with each pair of
contacts 77 being secured to the insulating support boards 71 by
means of a pair of nylon screws 79 which are threaded into tapped
openings in the spacer bar 73. Each of the contacts 77 is provided
with a contact part 81 and a terminal part 83. The terminal parts
83 of the contacts 77 are provided to receive conducting wires to
enable connection of the contacts 77 in an electric circuit. The
support bar 75, which is secured between the insulating support 71
by means of securing means 85, limits movement of the support
members 71 toward each other. The stationary secondary contact
assembly 53 is supported on the back wall support structure 13
(FIG. 3) by means of suitable securing means which secures the
support bar 75 to the back wall structure 13.
The movable assembly 15 (FIGS. 6 and 7) comprises a movable
supporting frame assembly 89 (FIGS. 8 and 9) with a molded-case
type circuit breaker 91 and a static trip device 93 (FIGS. 6 and 7)
supported thereon. The movable frame assembly 89 comprises a
generally U-shaped supporting frame 95 (FIGS. 8 and 9) with a
support plate 97 secured thereto. A molded-case type multi-pole
circuit breaker 91 is fixedly mounted on the support plate 97. The
circuit breaker 91 is of the type described in the patent to Howard
A. Wagner, Patent No. 3,530,414. The circuit breaker 91 comprises
an insulating housing 101 (FIG. 6) having an opening in the front
thereof with an insulating handle 103 protruding through the
opening to permit manual operation of the circuit breaker. An
insulating trip bar 105 is supported for pivotal movement about a
pivot 107 (FIG. 7) and movable in a counterclockwise (FIG. 7)
direction to trip the circuit breaker in a manner well known in the
art and described, for example in the above-mentioned U.S. Pat. No.
3,530,414.
A pair of elongated slide members 109 fit in the tracks 21 (FIG. 4)
to support the movable assembly 15 for sliding movement on the
tracks 21 of the stationary assembly. A pair of projections 113 are
fixedly secured on opposite sides of the supporting frame 95. The
projections 113 move in the slots 23 (FIG. 5) of the side plates 19
of the stationary assembly and they cooperate with the lever arms
33 in a manner to be hereinafter described. A pair of interlock
members 115 are supported on the opposite side plates of the
supporting frame 95. Each of the interlock members 115 is pivotally
supported on the associated side plates for movement about a pivot
pin 117 (FIG. 9) that is intermediate the ends of the interlock
member 115. Each of the interlock members 115 is provided with a
pin 119 (FIGS. 8 and 9) which protrudes through an opening 121 in
the associated side plate of the frame 95 (FIG. 9), and a separate
tension spring 123 is connected to each of the pins 119 to bias the
associated interlock member 115 in a clockwise (FIG. 9) direction.
A separate interlock pin 127 is provided on each of the interlock
members 115 for locking the movable assembly 15 in predetermined
positions on the stationary assembly 13 in a manner to be
hereinafter described.
The movable assembly 15 comprises trip-actuating means 133. The
trip-actuating means 133 comprises an elongated member 135 having a
pair of slots 137 (FIG. 9) therein which loosely receive rivets 138
that extend through the slots 137 and are secured to the one side
of the supporting frame 95. The slots 137 enable rectilinear
vertical movement of the member 135. The member 135 is provided
with a slot 141 therein which receives a pin 143 that is fixedly
secured to the one interlock member 115. The member 135 is provided
with a bent over portion at the lower end thereof which has opening
therein for receiving one end of an intermediate member 145 (FIGS.
2 and 6) which is pivotally mounted intermediate the ends thereof,
by means of a member 147, on a support bracket 149 that is secured
to the housing of the circuit breaker 91. The intermediate member
145 extends through an opening in a generally L-shaped member 151
(FIGS. 2, 6 and 7) which is also supported on the support bracket
149. The member 151 is secured to a plunger 155 that extends inside
of the circuit breaker housing. A spring 159 is mounted on the
plunger 155, and supported between a stationary part 160 and a
spring support 160' that is secured to the plunger 155, to bias the
plunger 155 and parts connected thereto downward to the
non-tripping position seen in FIGS. 2, 6 and 7. The members 151,
155 serve as actuating means for actuating the trip bar 105 upon
operation of the one interlock member 115. Upon counterclockwise
movement of the one interlock member 115 about the pivot 117 (FIG.
7) the pin 143 (FIG. 9) on the interlock member 115 will engage the
elongated member 135 at the bottom of the slot 141 to move the
elongated member 135 downward (FIGS. 2, 6 and 7). Upon downward
movement of the elongated member 135, this member will pivot the
intermediate member 145 in a counterclockwise (FIGS. 2 and 6)
direction about the pivot 147. Counterclockwise movement of the
intermediate member 145 will move the actuating means 151, 155
upward (FIGS. 2, 6 and 7) against the bias of the spring 159 during
which movement the plunger 155 will move the trip bar 105 in a
counterclockwise (FIG. 7) direction about the pivot 107 to a
tripped position to trip the circuit breaker 91 in a manner
described in the above-mentioned U.S. Pat. No. 3,530,414. As long
as the interlock member 115 is held in the tripped position the
trip bar 105 will be held in the tripping position and the circuit
breaker will be maintained in the tripped condition. Upon release
of the one interlock member 115, the associated spring 123 will
bias the interlock member 115 back to the position seen in FIGS. 6
and 7, and the spring 159 will bias the plunger 155, the
intermediate member 145 and elongated rod member 135 back to the
initial or non-tripping position seen in FIGS. 2, 6 and 7.
The circuit breaker 91 is a three-pole circuit breaker. There are a
pair of movable main terminals 161 for each pole of the circuit
breaker to enable connection of the circuit breaker in an electric
circuit. As can be seen in FIG. 14, each of the main terminals 161
comprises a generally U-shaped conductor 163, that is connected to
the circuit breaker, and a pair of clip-on type contact structures
165 connected to the legs of the conductor 163 for plug type
connection with the stab conductor 59 of the associated stationary
main terminal structure 51.
The movable assembly 15 also comprises a movable secondary contact
structure 171 (FIGS. 10 and 11). The movable secondary structure
171 comprises a pair of flat insulating boards 173 that are
connected together by a U-shaped channel member 175 and held in a
spaced relationship by means of three generally U-shaped insulating
support members 177. A plurality of pairs of resilient contacts 179
are secured to the opposite sides of the insulating supports 173
with each of the contacts 179 comprising a terminal part 181 at one
end thereof and a contact part 183 at the opposite end thereof. The
contacts 179 are bent over to provide a space between the contacts
183 that is less than the space between the contacts 77 (FIG. 13)
so that upon movement of the movable assembly into the connected
position the resilience of the contacts 179 will provide contact
pressure between the movable secondary contact portions 183 and the
stationary secondary contacts 77. As can be understood with
reference to FIGS. 10-13, when the movable assembly is moved to the
test position each pair of contacts 183 will resiliently engage the
associated pair of contacts 81, and each of the U-shaped insulating
support members 177 will straddle the stationary insulating support
boards 71 moving between adjacent pairs of the elongated stationary
contacts 77 to guide the movable secondary contact structure 71
into alignment with the stationary secondary contact structure
53.
The internal mechanism of the circuit breaker 91 is of the type
described in the above-mentioned U.S. Pat. No. 3,530,414. Under
overload current conditions the trip bar 105 (FIGS. 6 and 7) is
operated to the tripped position by means of an electromagnetic
trip actuator that is actuated by means of the static trip device
93 in the manner described in the above-mentioned U.S. Pat. No.
3,530,414. The static trip device 93 is operated by means of an
overload sensed by any one of three transformers or current
monitors 191. There are two upper current monitors 191 (one on each
of the two outside poles) and one lower current monitor on the
center pole.
Referring to FIG. 3, the movable assembly 15 is shown in the fully
connected position with relation to the stationary assembly 13. In
this position, the movable secondary contact structure 171 is in
engagement with the stationary secondary contact structure 53 and
the movable main terminal structures 161 are in engagement with the
stationary main terminal structures 51. The movable assembly 15 is
held or locked in the connected position seen in FIG. 3 by means of
the pins 127 on the interlock members 115 of the movable assembly
15 which are engaged in the notches 25 of the stationary assembly
13. In order to withdraw the movable assembly 15 from the connected
position, the interlock members 115 must first be moved to the
non-interlocking position. In order to defeat the interlock an
operator will depress one of the interlock members 115 moving the
one interlock member 115 in a counterclockwise direction about the
pivot 117 and, with the other hand pivot the interlock defeating
member 41 in a clockwise (FIG. 3) direction to move the depression
47 under the pin 127. The operator may then release the one
interlock member 115 and the interlock defeating member 41 engaging
the pin 127 will hold or prop the interlock member 115 in the
non-interlocking position. The operator may then similarly move the
other interlocking member 115 to the non-interlocking position and
move the other interlock defeating member 41 to the defeating
position under the pin 127 to hold or prop the other interlock
member 115 in the non-interlocking position. With the interlocking
members 115 in the non-interlocking position, the operator will
then crank the handle 31 in a counterclockwise (FIG. 3) direction
during which movement the lever members 31, of the stationary
assembly, operating against the projections 113 of the movable
assembly will move the movable assembly 15 in a rectilinear
direction to the left as seen in FIG. 3. As the movable assembly 15
moves to the left, the pins 127 of the interlocking members 115
will ride on the top surfaces of the side plates 19 and the
interlock defeating members 41 will fall back to the
non-interlocking position seen in FIG. 3. Movement to the left by
operation of the levering device 31 will be arrested when the pins
127 of the interlocking members 115 fall in the notches 27 of the
side plates 19. In this position, the movable main terminals 161
will be disconnected or disengaged from the movable main terminals
51 and the movable secondary contact structure 171 will still be in
engagement with the stationary secondary contact structure 53 so
that the control circuits of the circuit breaker can be operated
under test conditions. In order to further withdraw the movable
assembly 15 from the test position that the assembly is in when the
pins 127 of the interlocking members 115 are in the notches 27, an
operator with both hands will pivot the interlocking members 115 to
the non-interlocking position and manually pull the circuit breaker
outward which movement is relatively easy since there is no
frictional engagement between the main movable terminals 161 and
the main stationary terminals 51. The movable assembly will be
stopped in the completely disconnected position when the pins 127
drop into the slots 29. In the completely disconnected position,
the movable secondary contact structure 171 is disconnected from
the stationary secondary contact structure 53.
The movable assembly 15 is movable from the completely disconnected
position, wherein the pins 127 are in the slots 29, by an operator
who will depress the ends of the interlocking members 115 while
pushing in on the movable assembly 15. If the operator releases the
interlocking members 115 after he has started the movable assembly
moving inward, the pins 127 will ride on the top of the plates 19
until they drop into the notches 27 to stop movement of the movable
assembly 15 in the test position wherein the movable main terminals
161 are disconnected from the stationary main terminals 51 and the
movable secondary contact structure 171 is connected to the
stationary secondary contact structure 53. The operator can move
the movable assembly 15 from the test position by defeating the
interlock members 115, holding them downward, and pushing in until
the pin members 127 ride on the top surfaces of the plates 19 which
movement will move the projections 113 into the slots 37 in the
levers 33. Thereafter the operator can operate the handle 39 in a
clockwise direction to lever the movable assembly 15 into the
completely connected position seen in FIG. 3. As was hereinbefore
set forth, at any time the interlock member 115 on the left (FIG.
2) is in the non-interlocking position the trip actuating structure
133 will be in the tripping position holding the trip bar 105 in
the tripped position to trip the circuit breaker if the circuit
breaker was not previously tripped and to maintain the circuit
breaker in a tripped condition. It can be understood that for some
applications only one interlock member 115 and one interlock
defeating member 41 can be provided with the trip actuating means
133 being operatively connected to the one interlock member
115.
Another embodiment of the invention is illustrated in FIGS. 15 and
16. Referring to FIGS. 15 and 16, a stationary assembly 213 is
shown therein which is identical to the stationary assembly 13
hereinbefore described except for the levering mechanism 231 which
will be hereinafter described. Certain parts are left out of the
FIGS. 15 and 16 for the purpose of clarity. The levering mechanism
231 comprises a lever arm 233 which is welded or otherwise fixedly
secured to a lever 235. The lever arm 233 and lever 235 are fixedly
supported on a shaft 237 that extends across the unit and that is
supported on the side plates for movement about an axis normal to
the plane of the paper as seen in FIG. 15. Another lever 235 is
secured to the opposite end of the shaft 237. Each of the levers
235 is provided with a slot 239 at the upper end thereof for
cooperating with the associated projection 113 (FIG. 2) of the
movable assembly in the same manner as was hereinbefore described.
As can be understood with reference to FIG. 16, an additional lever
arm 241 is welded to the lever arm 233 to provide a pair of spaced
lever arms with each of the spaced lever arms having an elongated
slot 245 therein. A drive rod 249, having a threaded part 251
intermediate the ends thereof, is supported on an internally
threaded support 253 that is welded to one of the side plates of
the assembly. The rod 249 threadedly engages the support 253 so
that upon rotation of the rod 249 the rod will be moved axially on
the support. The rod 249 is formed with a hexagonal end part 255
for receiving a tool 257, indicated by broken lines in FIG. 15,
that may be placed onto the hexagonal part 255 and rotated to
rotate the rod 249. A rigid metal boss 259, having a pair of
reduced-diameter pin parts 261 at the opposite sides thereof, is
supported between the lever arms 233, 241 with the pins 261
extending through the slots 245 in the lever arms 233, 241. The rod
249 is provided with a reduced diameter end portion 265 that
extends through an opening in the boss 259. A pair of washers 267
are supported on the end portion 265 on opposite sides of the boss
259, and a pair of pins 271 extend through openings in the end
portion 265 to hold the washers in place. When it is desired to
operate the levering device 231, a tool 257 is applied to the
hexagonal part 255 and the rod 249 is rotated moving axially to
move the boss 259 axially. During this movement the projections 261
move in the slots 245 to drive the lever arms 233, 241 and levers
235. The levers 235 cooperate with the projections 113 (FIG. 2) of
the movable assembly to move the movable assembly in the same
manner as was hereinbefore set forth. The interlock defeating
members 41 of the stationary assembly cooperate with the
interlocking members 115 (FIG. 3) of the movable assembly in the
same manner as was hereinbefore described.
From the foregoing, it can be understood that there is provided by
this invention, improved drawout switchgear comprising interlock
means automatically operable to lock the movable assembly in a
fully connected position and defeatable to enable withdrawal of the
movable assembly, with interlock defeating means manually operable
to a defeating position to hold the interlock means in a
non-interlocking position while an operator operates a lever
mechanism to lever the movable assembly from the fully connected
position to a position wherein the main terminals are disconnected.
Trip actuating means is connected to the interlock means to trip
the circuit breaker upon movement of the interlock means to the
non-interlocking position and to maintain the circuit breaker in a
tripped condition so long as the interlock means is in the
non-interlocking position. Improved secondary contact means is
provided for connecting and disconnecting the control parts of the
drawout switchgear in a circuit. The secondary contact means
comprises a stationary secondary contact structure and a movable
secondary contact structure comprises a pair of flat insulating
boards supported in a spaced relationship and a plurality of pairs
of stationary contacts on the opposite or outer sides of the
insulating support boards. The secondary movable contact structure
comprises a pair of flat insulating support boards with generally
U-shaped insulating spacing means supporting the insulating support
boards in a spaced relationship and a plurality of pairs of movable
secondary contacts on the opposite sides of the insulating support
boards. During a closing operation of the secondary contact
structures, each of the U-shaped insulating spacers on the movable
secondary contact structure straddles the outer sides of the
insulating boards of the stationary secondary contact structure and
the legs of the U-shaped insulating spacers move between adjacent
stationary contacts of the stationary secondary contact structure
to guide the contacts of the movable secondary contact structure
into alignment with the contacts of the stationary secondary
contact structure.
* * * * *