U.S. patent number 3,600,540 [Application Number 04/874,648] was granted by the patent office on 1971-08-17 for motor-operated spring-closing circuit breaker.
This patent grant is currently assigned to Westinghouse Electric Corporation. Invention is credited to Fred Bould.
United States Patent |
3,600,540 |
Bould |
August 17, 1971 |
MOTOR-OPERATED SPRING-CLOSING CIRCUIT BREAKER
Abstract
A circuit breaker comprises spring closing means and a motor
drive structure for charging the spring-closing means with improved
means supporting the motor drive structure in a cooperating
relationship with the spring closing means.
Inventors: |
Bould; Fred (Pittsburgh,
PA) |
Assignee: |
Westinghouse Electric
Corporation (Pittsburgh, PA)
|
Family
ID: |
25364247 |
Appl.
No.: |
04/874,648 |
Filed: |
November 6, 1969 |
Current U.S.
Class: |
200/400;
200/50.35 |
Current CPC
Class: |
H01H
3/3005 (20130101); H01H 3/30 (20130101); H01H
2003/3063 (20130101) |
Current International
Class: |
H01H
3/00 (20060101); H01H 3/30 (20060101); H01h
003/00 () |
Field of
Search: |
;335/68,76
;200/153.23,153 ;74/2,575 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hirshfield; Milton O.
Assistant Examiner: Weldon; Ulysses
Claims
I claim as my invention:
1. A circuit breaker comprising a support structure, a circuit
breaker mechanism supported on said support structure, said support
structure comprising a baseplate and a pair of spaced generally
parallel sideplates connected to said baseplate, a pair of spaced
generally parallel center plates connected to said baseplate within
the dimension between said sideplates and supported in a generally
parallel relationship with respect to said sideplates, said circuit
breaker mechanism comprising a closing spring means and a motor
drive structure operable to charge said closing spring means, said
closing spring means comprising a crankshaft supported for rotation
on said center plates and a pair of closing springs connected to
said crankshaft, a ratchet wheel connected to said crankshaft, a
reciprocating pawl structure mounted on said crankshaft for
movement relative to said crankshaft, said motor drive structure
comprising a main body motor part and a rotatable output shaft
structure extending from said main body motor part, said rotatable
output shaft structure comprising an end part and an intermediate
part, said intermediate part being intermediate said end part and
said main body motor part, support means supporting said motor
drive structure on said support structure, said support means
comprising a first support and a second support, said first support
fixedly supporting said main body motor part on one of said
sideplates, said second support comprising a bearing support
supported on one of said center plates and receiving said end part
of said output shaft structure therein, said bearing support
supporting said end part of said output shaft structure against
radial movement with said end part rotating on said bearing support
during operation of motor drive structure, and upon energization of
said motor drive structure said output shaft rotating and said
intermediate part operating against said reciprocating pawl
structure to advance said ratchet wheel to thereby rotate said
crankshaft to charge said closing spring means.
2. A circuit breaker according to claim 1, said intermediate part
comprising an operating arm movable upon rotation of said output
shaft through a first part of a 360.degree. revolution of said
output shaft structure to move said reciprocating pawl structure
against a tooth of said ratchet wheel to advance said ratchet
wheel, and spring means operating to return said reciprocating pawl
structure to position said reciprocating pawl structure adjacent
another tooth of said ratchet wheel during the second part of said
360.degree. revolution of said output shaft structure.
3. A circuit breaker according to claim 1, and said intermediate
part of said output shaft structure comprising a roller arm part
operable against said reciprocating pawl structure upon rotation of
said output shaft structure.
4. A circuit breaker according to claim 3, and said second support
comprising a ball bearing support supporting said end part against
radial movement during operation of said motor drive structure.
5. A circuit breaker according to claim, said circuit breaker being
a multipole circuit breaker, said circuit breaker mechanism
comprising an elongated jackshaft common to all of the poles of
said circuit breaker, each of said poles comprising a stationary
contact and a movable contact, means operatively connecting each of
said movable contacts with said jackshaft, means supporting said
jackshaft on said sideplates and said center plates for movement
about the elongated axis thereof, a closing cam on said crankshaft
between said center plates, link means operatively connecting said
closing cam with said jackshaft, said motor drive structure being
operable to operate said reciprocating pawl structure to rotate
said crankshaft from a spring discharged position to a spring
charged position to charge said closing spring means, latch means
for latching said crankshaft in the spring charged position, upon
release of said latch means said closing spring means rotating said
crankshaft and said closing cam operating through said link means
and said jackshaft to move said movable contacts to the closed
position.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
The applications of Fred Bould et al., Ser. No. 770,296 filed Oct.
24, 1968, and of Fred Bould, Ser. No. 836,313 filed June 25, 1969
are related to the present application in a manner that will be
hereinafter set forth under the description of the prior art.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Motor-operated spring-closing circuit breaker.
2. Description of the Prior Art
In the above-mentioned application of Fred Bould et al., Ser. No.
770,296, there is disclosed a spring-closing mechanism for closing
a circuit breaker, with manual means for charging the
spring-closing mechanism. In the above-mentioned application of
Fred Bould, Ser. No. 836,313 there is disclosed a motor-operated
spring-closing circuit breaker. The present invention is an
improvement over both of the above-mentioned applications in that
the present invention provides an improved motor-operated
spring-closing circuit breaker with improved means supporting the
motor drive structure in a cooperating relationship with the
spring-closing means. The improved supporting or mounting means
provides a precise location of the motor roller arm preventing
undesirable deflections of the roller arm under load conditions and
keeping the loads on the motor housing within safe limits. The
mounting is such as to facilitate assembly and removal of the motor
drive structure and a standard drill-type motor body can be
utilized in the combination.
SUMMARY OF THE INVENTION
A circuit breaker comprises spring-closing means and a motor drive
structure for charging the spring-closing means, with improved
means supporting the motor drive structure for operating the
spring-closing means. The circuit breaker comprises a metallic
housing structure comprising a baseplate and a pair of spaced
generally parallel sideplates connected to the baseplate with a
pair of spaced generally parallel center plates connected to the
base plate within the widthwise dimension of the sideplates. The
center plates support a crankshaft that is rotatable about an axis
to charge a pair of closing springs, and a ratchet is connected to
the crankshaft. The sideplates and center plates support a
jackshaft that is movable to operate the movable contacts of the
breaker. A reciprocating pawl structure is supported to advance the
ratchet to thereby charge the closing springs. The motor drive
structure comprises a main body motor part and a rotatable output
shaft structure extending from and supported on the main body motor
part. The main body motor part is supported on one of the breaker
sideplates and the nose or end part of the output shaft structure
is supported on a bearing support that is supported on one of the
center plates. Upon energization of the motor and rotation of the
output shaft structure, a cam part or roller arm on the output
shaft structure between the nose and the main body motor part
rotates and operates against the reciprocating pawl structure to
advance the ratchet wheel to thereby charge the closing springs. By
supporting both the main body part and the end part of the motor
drive structure, the roller arm is maintained in the operative
position under operating loads and the loads on the body of the
motor are kept within safe limits. A standard drill-type motor,
including an aluminum motor housing, can be utilized in the
combination. The motor drive structure is readily assembled in
available space between one of the sideplates and one of the center
plates of the breaker support structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end view, with parts broken away and with certain
parts left out for the purpose of clarity, of a circuit breaker
constructed in accordance with principles of this invention;
FIG. 2 is a sectional view taken generally along the line II-II of
FIG. 1;
FIG. 3 is a partial sectional view taken generally along the line
III-III of FIG. 1 with the crankshaft and closing spring being
shown in side elevation; and
FIG. 4 is a partial sectional view, with parts broken away and with
parts left out for the purpose of clarity, looking down on the
motor drive structure and reciprocating pawl structure to
illustrate the support of the motor drive structure on the one
center plate and one sideplate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown in FIGS. 1 and 2 a
three-pole circuit breaker 5 comprising a support structure or
housing structure 7 and a circuit breaker structure 9 supported on
the housing structure 7. The housing structure 7 comprises a
metallic baseplate 11, a pair of spaced metallic side plates 13
fixedly secured to flanges of the base plate 11, a pair of metallic
center plates 17 fixedly mounted on the base plate 11 and a
backwall structure indicated generally at 19.
The circuit breaker structure 9 is a three-pole structure
comprising a stationary contact 21 (FIG. 2) and a movable contact
23 for each pole unit. Each of the movable contacts 23 is supported
on a conducting contact arm 25 that is pivotally supported on a
terminal conductor 27 by means of a pivotal support means 29. In
each pole unit, a separate insulating connecting member 31 is
pivotally connected at one end thereof to the contact arm 25 and at
the other end thereof to a lever 33 that is welded to a common
jackshaft 35 that extends across all of the poles of the circuit
breaker. There is a separate lever 33 for each pole unit welded to
the common jackshaft 35. Only one of the contact structures is
shown in FIG. 1. The contact structures for the center pole and for
the left-hand (FIG. 1) pole are left out of the drawing in FIG. 1
merely for the purpose of clarity. It can be understood that the
contact structures for all three-pole units are the same as the one
contact structure shown in FIGS. 1 and 2.
The jackshaft 35 is supported for pivotal movement, about the
elongated axis thereof, on the sideplates 13 and center plates 17.
The connecting member 31, levers 33 and jackshaft 35 are part of a
stored-energy spring-closing mechanism 39 that is operable to close
the contacts 23, 21. The mechanism 39 comprises a link 41 that is
pivotally connected, at one end thereof, to the lever 33 of the
center pole by means of a pin 43. The link 41 is pivotally
connected at the other end thereof, to a link 45 by means of a knee
pivot pin 47. A roller member 49, that serves as a cam follower, is
mounted on the pin 47 to cooperate with a closing cam 51. The link
45 is pivotally connected at the other end thereof to a latch
member 53 by means of a pin 55. The latch member 53 is mounted for
pivotal movement about a fixed pivot pin 57 that is supported on
the left-hand (FIG. 1) center plate 17. A tension spring 59 is
connected to the pin 55 to reset the linkage following a tripping
operation of the circuit breaker. The latch member 53 engages the
periphery of a trip shaft 63 in proximity to a cutout portion of
the shaft 63, which cutout portion is provided so that when the
trip shaft 63 is rotated in a counterclockwise direction the latch
member 53 will be free to move in the cutout portion to the tripped
position. The trip shaft 63 is supported for pivotal movement about
the elongated axis thereof between one of the center plates 17 and
one of the sideplates 13.
A roller latch 67 (FIG. 2) is rotatably supported on and between
the twin plates of the closing cam 51. The closing cam 51 is
fixedly secured to a crankshaft 71 that is rotatably supported on
suitable bearings that are secured to the center plates 17. A pair
of crank arms 73 are fixedly mounted on the crankshaft 71 at the
opposite ends of the crankshaft 71. A ratchet member 75 is fixedly
mounted on the crankshaft 71. A reciprocating pawl structure 78
(FIGS. 1 and 3) is supported on the crankshaft 71 for pivotal
reciprocating movement relative to the crankshaft 71 to cooperate
with the ratchet 75. A separate tension spring 79 is operatively
connected at the end of each of the crank arms 73 by means of a
pivot pin 80. Each of the springs 79 is connected to a spring
support 81 that is pivotally connected to the associated arm 73 by
means of the associated pivot pin 80. Each of the tension springs
79 is connected, at the other end thereof, to a rod 82 that is
secured to the center plate 17. A manual operating mechanism,
indicated generally at 83 (FIG. 1), is provided for manually
charging the closing springs 79. A latch member 85 (FIG. 2) is
pivotally mounted on a pin 87 and biased in a clockwise (FIG. 2)
direction to the latching position wherein the latch 85 engages the
roller 67 to latch the closing cam 51 and crank shaft 71 to prevent
counterclockwise movement of the closing cam 51 and crank shaft
71.
The circuit breaker is shown in FIG. 2 in the contact open position
with the stored energy closing springs 79 in the charged condition.
As is shown in FIG. 2, the spring support pins 80 of the tension
springs 79 are below a line between the center of the spring
support rod 82 and the center or axis of the crank or shaft 71 so
that the charged tension springs 79 are operating to bias the
crankshaft 71 in a counterclockwise direction. Counterclockwise
movement of the crankshaft 71 is prevented by the engagement of the
latch member 85 with the latch roller 67 that is mounted on the
closing cam 51. The latch member 85 is operated to the unlatching
position to close the circuit breaker in a manner described in the
above-mentioned application of Fred Bould et al., Ser. No. 770,296.
When it is desired to close the breaker, the latch 85 is pivoted in
a counterclockwise (FIG. 2) direction to thereby release the roller
67. When the roller 67 is released, the closing cam 51 and the
crank shaft 71 are free to rotate in a counterclockwise direction,
and the closing springs 79, operating on the crank arms 73, operate
to rotate the crank shaft 71 in a counterclockwise direction as the
springs 79 discharge. During this movement, the closing cam 51 will
force the roller 49, and the link 41, to the closed position.
During this closing movement of the link 41, of the lever 33 (FIG.
2) of the center pole unit is forced in a counterclockwise
direction to rotate the jackshaft e5 counterclockwise to
simultaneously move the three contact arms 25 in a clockwise
direction about the pivots 29 to the closed position. In the closed
position, the engagement of the closing cam 51 with the roller 49
serves to prop the link member 41 in the closed position to thereby
maintain the jackshaft 35 and contacts 23 in the closed
position.
With the contacts in the closed position and the closing spring
discharged, the circuit breaker may be automatically tripped open,
in response to an overload above a predetermined value in any of
the pole units, by operation of the trip shaft 63 in a manner
described in the patent application of Nagar J. Patel, Ser. No.
770,236, filed Oct. 24, 1968. During the tripping operation, the
trip shaft 63 is rotated in a counterclockwise (FIG. 2) direction.
When the trip shaft 63 is rotated counterclockwise, the trip shaft
moves to permit the latch member 53 to move in the cutout portion
of the trip shaft 63 thereby permitting the latch member 53 to move
in a counterclockwise direction about the pivot 57 to the tripped
position. The compressed contact springs 93 (FIG. 2) and an opening
spring 99 (FIG. 1) then operate to move the contact arms 25 toward
the open position which movement occurs because the pivot 55 is
free to move so that the link 45 can move to the tripped position
with the toggle 45, 41 collapsing to permit the lever 33 and jack
shaft 35 to move in a clockwise direction to the tripped open
position. Thus, movement of the trip shaft 63 to the tripped
position permits the members 41, 45, 53 to move to the tripped
position wherein the roller 49 and link 41 no longer restrain the
lever 33 in the closed position, and the springs 93, 99 operate to
move the jackshaft 35 and the three contact arms 25 to the tripped
open position.
With the circuit breaker in the tripped open position, the breaker
is reset and the closing springs 79 are charged by operation of the
motordrive structure 101 in a manner to be hereinafter more
specifically described. In order to reset the circuit breaker and
charge the closing springs 79, the crankshaft 71 is rotated through
an angle of more than 180.degree. of the spring charged operating
position seen in FIG. 2. As the crankshaft 71 moves to the position
seen in FIG. 2, the roller 49 rides off of the peak of the cam 51
into the depression seen in FIG. 2. When the roller 49 is free to
move into the depression of the cam 51, the spring 59 (FIG. 1)
biases the latch 53 clockwise (FIG. 2) to move the latch 53 to the
reset position pulling links 45, 41 and the roller 49 to the reset
position wherein the roller 49 is positioned in the depression of
the cam 51 (FIG. 2). When the latch 53 moves out of the notch of
the trip shaft 63, suitable spring means operates to rotate the
trip shaft 63 clockwise to the latching position wherein the
periphery of the trip shaft 63 again latches the latch member 53 to
latch the parts in the reset position seen in FIG. 2. As the
crankshaft 71 moves more than 180.degree. to the position seen in
FIG. 2, the springs 79, which are moved overcenter, take over to
bias the crankshaft 71 in a counterclockwise (FIG. 2) direction,
and the roller 67 engages the latch 85 to latch the crankshaft 71
in the charged position seen in FIG. 2, and the circuit breaker is
prepared for another closing operation.
When the circuit breaker is in the contact closed position with the
stored energy closing springs 97 discharged the spring closed means
is operated to the charged position by operation of the motor drive
structure 101 (FIGS. 1, 3 and 4) to rotate the crankshaft 71
through an angle of slightly more than 180.degree. (approximately
184.degree.) to charge the springs 79 during which movement the
roller 49 rides on a fixed radius of the cam 51 to a position just
short of the peak of the cam surface of the cam member 51. This
charging movement of the cam 51 is more specifically described in
the above-mentioned application Ser. No. 770,296.
With the parts in the contact closed spring charged position, the
following sequence of operations can occur.
Upon the occurrence of an overload above a predetermined value, the
trip means indicated generally at 95 (FIG. 1) is automatically
operated to rotate the trip shaft 63 to release the latch member 53
and permit the toggle 41, 45 to effect an opening operation in the
same manner as was hereinbefore described. With the toggle 41, 45
collapsed, the spring 59 operates to draw the roller 49 into the
depression of the cam 51 resetting the linkages 53, 41, 45 and the
trip shaft 63 is moved by spring means into the latching reset
position seen in FIG. 2. The parts at the end of this tripping
operation will be in the position seen in FIG. 2 wherein the
mechanism is reset and relatched, and wherein the roller member 49
is in the depression of the cam 51 so that the parts are prepared
for a closing operation. When the closing springs 79 are charged an
operator can immediately operate the closing latch 85 (FIG. 2) to
release the roller 67 whereupon the circuit breaker is operated to
the closed position in the same manner as was hereinbefore
described. With the parts in the closed position, if an overload
above the predetermined value occurs the trip mans 95 will be
automatically operated to rotate the trip shaft 63 to the tripped
position to effect a tripping operation in the same manner as
mentioned before described. With the parts in the tripped position
and the closing springs 79 discharged, another charging operation
of the closing springs 79 will be required in order to provide
another closing operation. Thus, when the circuit breaker is in the
contact closed spring charged position, the circuit breaker can be
tripped and then closed and then tripped again in rapid
sequence.
The reciprocating pawl structure 78 (FIG. 3) comprises a
reciprocating member 105 that comprises a pair of spaced twin
plates, that straddle the ratchet wheel 75, and a bight portion 107
connecting the twin plates. The reciprocating member 105 is mounted
on the crank shaft 71 for movement relative to the crank shaft 71
about the axis of the crank shaft 71. A driving pawl 109 is
pivotally mounted on the reciprocating member 105 between the twin
plates of the member 105 by means of a pin 113, and a torsion
spring 115 biases the pawl 109 in a counterclockwise direction
about the pin 113 into engagement with the ratchet wheel 75. A
tension spring member 117 biases the reciprocating member 105 in a
clockwise direction about the crankshaft 71. A holding pawl 121 is
pivotally mounted on one of the center plates 17 by means of a pin
123 and biased in a counterclockwise direction, by means of a
torsion spring 125, into engagement with the ratchet wheel 75.
The motor drive structure 101 comprises a main body motor part 131
and an output shaft structure 133 supported on the main body motor
part 131. The output shaft structure 133 comprises an end part or
nose part 135 and a roller arm 137 intermediate the end part 135
and the main body motor part 131. A roller member 139 is rotatably
mounted on a pin 141 that is supported on the roller arm 137. The
main body motor part 131 comprises a motor housing 148 and an
electric motor structure supported within the motor housing 148. A
standard aluminum housing drill-type motor has been successfully
used in the combination with the back handle of the motor removed
and with the two screws 149, that formerly secured back handle of
the drill-type motor to the motor housing 148, being used to secure
the motor housing 148 to the one sideplate 13. The screws 149
support the motor drive structure 101 on the sideplate 13, and an
additional bearing support 151 is supported on one of the center
plates to provide additional support for the end part 135 of the
output shaft structure 133 to prevent undesirable deflection of the
output shaft structure under operating load conditions and to keep
the loads on the motor housing within safe limits. With the
improved mounting means of this invention a standard aluminum
housing drill-type motor can be utilized in the combination with
the roller arm being positively located and with the overall
support means keeping the loads on the motor housing within safe
limits.
As can be understood with reference to FIG. 4, the bearing support
151 is a roller bearing comprising a race 153 fixedly supported in
an opening on the one center plate 17, a journal 155 that receives
the end part 135 of the output shaft structure 133 and a plurality
of ball bearings 157 disposed around the journal between the
journal and race to permit the journal and end part 135 to freely
rotate relative to the race 153 and plate 17 while supporting the
end part 135 against radial movement.
As can be seen in FIG. 3, the closing springs 79 are in the charged
position with the closing latch 85 (FIG. 2) engaging the roller 67
of the cam 51 to latch the crankshaft 71 release of the latch 85,
the springs 79 discharge rotating the crankshaft 71 approximately
180.degree. to close the circuit breaker in a manner hereinbefore
described. Upon discharge of the closing springs 79 suitable limit
switch means is actuated in a well-known manner by the breaker
mechanism to energize the motor drive structure 101. Upon
energization of the motor drive structure 101, the output shaft
structure 133 is rotated in a clockwise (FIG. 3) direction about
the axis thereof. Upon clockwise (FIG. 3) rotation of the output
shaft structure 133 the roller arm 137 is rotated and during each
revolution of the output shaft structure 133 the roller 139,
operating against the bight part 107 of the reciprocating pawl
structure 78 moves the reciprocating pawl structure 78 in a
counterclockwise direction during which movement the driving pawl
of 109 operates against one of the teeth of the ratchet 75 to
advance the ratchet 75 and crankshaft 71. As the roller arm 137
moves 180.degree. from the position seen in FIG. 3, the
reciprocating pawl structure 78 will advance the ratchet 75 and
crankshaft 71 in a counterclockwise direction, and as the roller
arm 137 moves the remaining 180.degree. of a 360.degree.
revolution, the spring 117 will return the reciprocating pawl
structure 78 to the position seen in FIG. 3 with the holding pawl
121 holding the ratchet 75 and crankshaft 71 in the advanced
position. Thus, as the output shaft structure 133 rotates, the
ratchet 75 is advanced by the driving pawl 109 and alternately held
by the holding pawl 121 until the crankshaft 71 moves more than
180.degree. to an overcenter position wherein the charged closing
springs 79 again bias the crankshaft 71 in a counterclockwise
direction with the ratchet 75 and crankshaft 71 becoming latched
from closing movement by the latch member 85 (FIG. 2) which engages
the roller 67 on the cam 51 that is fixed to the crankshaft 71.
When the closing springs 79 reach the fully charged position, the
driving pawl 109 is adjacent a missing tooth portion 154 (FIG. 3)
of the ratchet 75 so that continued rotation of the motor will not
operate against the teeth of the ratchet 75, and the motor can be
brought to a stopped condition without damaging the parts and
without putting undue forces on the parts. The motor 101 is
automatically deenergized by suitable limit switch means in a
manner well known in the art.
* * * * *