Note: Descriptions are shown in the official language in which they were submitted.
~07~8 41PR-1976
The present invention relates to circuit breakers
o the industrial type which are equipped with motor operators
to afford the capability of operating the circuit breakers
from a remote control center either manually upon actuation
of a control switch or automatically in coordination with the
operations of other circuit breakers. ~otor operated industrial
circuit breakers thus have particular application as, for
example, process control switches of high current carrying
capacity and have the inherent benefit of also providing
automatic overload and short circuit protection. The typical
industrial circuit breaker of the molded case variety utilizes
a spring powered operating mechanism for articulating its
movable contacts into and out of engaging relation with its
fixed contacts. The motor operator is thus utilized to charge
the breaker operating mechanism spring, and once charged, the
energy stored therein is released to abruptly drive the breaker
movable contacts to their closed position. Illustrative of
prior art motor operated circuit breakers of this character
is the disclosure in the commonly assigned U.S. Patent No.
3,559,121, Powell et al, issued January 26, 1971.
It is accordingly a general object of the present
invention to provide an improved motor operated, industrial
molded case circuit breaker.
An additional object is to provide a circuit
breaker of the above character, wherein the motor operator
is compact and economical in design, and reliable in operation.
Yet another object of the invention is to provide
a circuit breaker of the above character which is selectively
operable either by the motor operator or manually, as desired.
3a A further object is to provide a circuit breaker
of the above character which is equipped with indicating means
for reliabl~ identifying the breaker condition.
.: . . .
. ~
.
41PR-1976
~076~
Other objects of the invention will in part be obvious
and in part appear hereinafter.
In accordance with the present invention, there is
provided a circuit breaker which is adapted for either manual
or motor driven operation, as desired. Motor driven
operation is achieved by the incorporation of a power unit
comprising a motor selectively drivingly coupled to the circuit
breaker operating mechanism and operating to charge the mechanism
spring incident to closing the breaker contacts. Upon
completion of a charging function, a closing solenoid is
energized to effect release of the stored energy, which powers
the breaker contacts to their closed position. Control elements
sensitive to the condition of the operating mechanism and
; the position of the breaker movable contacts function to
appropriately condition switching logic in the motor and closing
solenoid circuit for sequencing the charging and closing
functions in a reliable manner. The control elements further
function to selectively position indicator means effective to
visually identify the various breaker conditions.
Manual operation of the circuit breaker is effected
in the same manner, except that the motor is decoupled from
the breaker operating mechanism and a manual operating handle
is coupled thereto for charging the mechanism spring. An
interlock switch disables the motor circuit during a manual
charging function. The control elements function as in the
powered charging function to appropriately position the indica-
tor means. Once the operating mechanism is charged manually,
contact closure can be effected via the closing solenoid or
by manipulation of a button to release the stored energy.
As an important feature of the present invention, the
motor is a permanent magnet D.C. motor which offers the
distinct advantage of being readily susceptible to precise
.,. : .
41PR-19 76
dynamic brakiny. As a consequence, a motor of this type
can be abruptly braked to a stop at the conclusion of a
charging function with the power unit parts in their appropriate
starting positions poised for a subsequent charging function.
The invention accordingly comprises the features
of construction, combination of elements, and arrangement of
parts which will be exemplified in the detailed description
hereinafter set forth, and the scope of the invention will
be indicated in the claims.
For a fuller understanding of the nature and objects
of the invention, reference should be had to the following
detailed description taken in connection with the accompanying
drawings, in which:
FIGURE 1 is an isometric view of a circuit breaker
constructed according to an embodiment of the present invention;
FIGURE 2 is a side elevational view of the circuit
breaker of FIGURE l;
FIGU.RE 3 is a plan view, partially broken away, of
a power unit incorporated in the circuit breaker of FIGURE l;
FIGURE 4 is a side elevational view, partially in
section, depicting the drive portion of the power unit of
FIGURE 3;
FIGURE 5 is a fragmentary plan view of a portion of
: the power unit of FIGURE 3 depicting the positions of various
parts substantially at the midpoint of a powered breaker
mechanism charging cycle;
FIGURE 6 is a fragmentary plan view of a portion of
the power unit of FIGURE 3 showing the positions of the various
parts substantially at the midpoint of a manual charging cycle;
FIGURE 7 is a vertical sectional view of a portion
of the power unit of FIGURE 3 illustrating the positions of
the parts assumed for powered charging of the breaker operating
41PR-1976
10766'~
mechanism;
FIGURE 8 is a vertical sectional view of the same
portion of the power unit depicted in FIGURE 7, with the various
parts positioned to accommodate manual charging of the breaker
operating mechanism;
FIGURE 9 is an exploded perspective view illustrating
the manner of coupling the parts depicted in FIGU~ES 7 and 3
to the breaker operating mechanism;
FIGURE 10 is a fragmentary side elevational view
illustrating the operation of a hook in latching the breaker
movable contacts in their open circuit positions during a
breaker mechanism charging cycle;
FIGURE 11 is an enlarged, fragmentary elevational
view of a portion of FIC.URE 10;
FIGU~E 12 is a side elevational view of a circuit
breaker closing mechanism for articulating the hook of FIGURE
10;
FIGURE 13 is a fragmentary side elevational view
showing the parts of the closing mechanism of FIGURE 12 in
their armed positions assumed at the conclusion of a breaker
mechanism charging cycle;
FIGURE 14 is a fragmentary plan view illustrating
the manner of actuation of certain switches seen in FIGURES 3
and 12 which are utilized in the electrical control of the
operation of the power unit;
FIGURE 15 is a side elevational view of an indicator
mechanism operating to sense the various positions of breaker
operating mechanism parts and operating accordingly to control
an indicator display and the conditions of various switches
3a utilized in the power unit electrical control circuitry;
FIGURES16 through 19 are a series of fragmentary
side elevational vie~s illustrating the positio~ of the various
parts seen in FIGURE 15 at various points in the breaker charging
41P~-lg76
1076~i;~
and closing cycles;
FIGURE 20 iS a schematic diagram of the electrical
control circuit for the power unit; and
FIGURE 21 is a fragmentary, side elevational view
of an anti-pumping mechanism incorporated in the circuit
breaker of FIGURE 1.
Corresponding reference numerals refer to like
parts throughout the several views of the drawings.
Referring to FIGURES 1 and 2, the circuit breaker
of the present invention, generally indicated at 20, consists
of three subassemblies, namely, a circuit breaker assembly
22, a power unit assembly 24, and a cover assembly 26, all
secured together in stacked relation. The circuit breaker
assembly 22 includes the basic operating components of a
circuit breaker which preferably is of t'ne construction shown
in the commonly assigned Jencks and Castonguay Canadian
application, Serial No. 263,791, filed October 20, 1976. The
power unit assembly 24 includes a motor operator, to be
described below, for providing powered operation of the
circuit breaker assembly 22 from its open circuit or OFF
condition to its closed circuit or ON condition. A terminal
strip 28, mounted to the circuit breaker 20, facilitates
electrical connection to a control device (not shown) for the
purpose of affording remote operation of the circuit breaker
by way of the power unit assembly 24, The cover assembly 26
includes an operating handle 30 which may be used to operate
the circuit breaker 20 manually instead of via power unit 24.
As will be seen, to effectuate the operating handle 30 for
manual circuit breaker operation, a button 31 is depressed
to disengage the power unit 24 from circuit breaker assembly
22 and engage the handle with the circuit breaker operating
mecllanism. The cover assembly also includes a window 32
1076~8 4lPR-1976
through which a position indicator, to be described, is
visible to identify whether the contacts of the circuit
breaker assembly 22 are open or closed and when the circuit
breaker operating mechanism is charged preparatory to contact
closure. Manual controls for operating the circuit breaker
include an OFF button 34 and an O~l button 36. The OFF button
is depressed to trip the circuit breaker assembly 22 from its
O`l~ condition to its OFF condition, while the O~ button is
depressed to turn the circuit breaker ON once the breaker
operating mechanism is charged either via the power unit
assembly 24 or the manual handle 30.
The power unit assembly 24, best seen in FIGURE 3,
includes an electric motor 40 which, according to one feature
of the invention, is a permanent magnet, D.C. motor. The
output shaft 4~a of this motor is drivingly connected via a
coupling 42 to the input shaft 44 of a gear box, generally
indicated at 46. Input shaft 44, journaled by the gear box
housing 47, carries a worm 48 which engages a worm gear 50
mounted on a shaft 51, also journaled by the gear box housing.
Shaft 51 also carries a worm 52 which engages a worm gear 54
mounted on an output shaft 55 journaled by the gear box housing
47. As best seen in FIGURE 4, a crank arm 56 is keyed to the
lower end portion of output shaft 55 protruding through the
underside of gear box housing 47. An elongated link 57 is
pivotally connected at one end by a pin 58 to the free end of
crank arm 56 and is pivotally connected at its other end by a
pin 59 to a drive plate 60 (FIGURES 3-5). Comparing FIGURES 3
and 5, it is seen that for each full rotation in the counter-
clockwise direction of gear box output shaft 55, drive plate
6~ is first rotated approximately 120 in the counterclockwise
direction and then rotated back in the clockwise direction
120 to its initial, home position. As will be seen, motor 40
-- 6 --
41PR-1976
107~
is energized to drive the gear box output shaft through a
full turn in the counterclockwise direction to oscillate
drive plate 60 through a 120 arc pursuant to charging the
operating mechanism within the circuit breaker assembly 22.
Turning to FIGU~ES 7 through 9, drive plate 6~ sits
stop a hub 62 and is secured for rotation relative thereto by
a collar 64. The hub is mounted for rotation in an opening
66a in the floor 66 of the power unit assembly housing. This
rotatable hub is captured in floor opening 66a by a second
drive plate 68 fastened to its lower butt end. As best seen
in FIGURE 9, the second drive plate 68 carries a depending
pin 7Q which operates in a laterally elongated slot 72a
formed in a circuit breaker operating mechanism slide 72.
This operating slide, which corresponds to the operating
slide disclosed in the above-noted Canadian application,
is reciprocated fore and aft to charge the breaker mechanism
preparatory to closure of the breaker contacts.
As best seen in FIGURES 7 and 8, drive plate 60 is
provided with a central clearance opening 60a through which
2Q is received a vertical operating shaft 74. The lower terminal
portion 74a of this shaft is journalled in a central bore 62a
formed in hub 62. Drive plate 60 is, in turn, selectively
drivingly connected to shaft 74 by a coupling element 76
affixed to the shouldered portion 74b of the shaft located
below the drive plate. This coupling element is formed having
an upwardly extending one end, providing short tab 76a which
is normally received in a slot 60b in drive plate 60 (FIGURE 7).
The other end of coupling element 76 carries a longer, upturned
tab 76b which is engaged for counterclockwise rotation hy a
3Q shoulder 60c formed in drive plate 60, as best seen in FIGURES
3, 5 and 6. A compression spring 78, incorporated in hub 62,
acts against the underside of drive coupling 76 to normally bias
iO~6~ 41PR-1976
shaft 74 to an elevated position such that coupling member
tab 76a is engaged in drive plate slot 60b (FIGURE 7). Under
these circumstances, it is seen that counterclockwise rotation
of drive plate 60 via motor 40 and gear box 46 is communicated
to operating shaft 74 by way of coupling element 76. That is,
coupling element tab 76a is engaged in the closed ended slot
60b, while its tab 76b is engaged by shoulder 60c of the drive
plate to communicate counterclockwise rotation of the drive
plate to the operating shaft. At the conclusion of the 120
counterclockwise rotation of the drive plate, its return to
home position in the clockwise direction induces clockwise
rotation of the operating shaft by virtue of the engagement
of coupling element tab 76a in drive plate slot 60b. Coupling
element tabs 76a are accommodated in diametrically opposed slots
62b (FIGURES 3 and 5-8) formed in the upper portion of hub
62, such that, regardless of vertical position, clockwise and
counterclockwise rotation of operating shaft 74 is faithfully
coupled to the hub, and the operating slide 72 (FIGURE 9) is
thus reciprocated fore and aft to charge the circuit breaker
operating mechanism.
Continuing with reference to FIGURES 7 and 8, manual
operating handle 30 includes a hub portion 30a which is received
in a clearance opening 79a provided in ~e front wall 79 of
the cover assembly housing. The manual operating handle is
captured in place by a drive plate 80 secured to the butt end
of handle hub 30a. The upper terminal portion 74c of operating
shaft 74 projects through a hex-shaped central opening 80a in
drive plate 80 (FIGURE 9) to be normally accommodated in a
central recess 30b formed in handle hub 3Qa. Button 31 is
received in a cavity 30c formed in handle 30 and includes a
stem 31a which extends through a bore 30d into hub recess 30b
for abutting engagement with the upper end of operating shaft 74.
1~76~ 4lPR-1976
A compression spring 82 disposed in handle cavity 3~c normally
biases button 31 to its elevated position.
To effectuate the handle 3Q for manual operation of
the circuit breaker operating mechanism, button 31 is depressed,
as seen in FIGURE 8, to shift operating shaft 74 bodily downward
to a depressed position such as to position its upper terminal
portion 74c, which is hex-shaped, in rotatably driven engagement
with drive plate 80. With shaft 74 in this depressed position,
coupling element tab 76a drops out of drive plate slot 60b to
thus decouple the drive plate 60 from the shaft during counter-
clockwise rotation of the latter by manual operating handle 30.
It will also be noted that once coupling element tab 76a moves
out of registry with drive plate slot 60b, the upper end of
this tab bears against the underside of the drive plate
(FIGURE 6) to maintain the shaft 74 in its depressed position
against the bias of compression spring 78 for the major portion
of the cranking movement of the rotary operating handle 30 in
charging the breaker operating mechanism. Since coupling
element tab 76b has a greater vertical extent that tab 76a, de-
pression of the operating shaft 74 does not drop this tab below
the level of drive plate 60. However, during counterclockwise
rotation of shaft 74, this tab 76b simply swings away from the
stationary drive plate shoulder 60b (FIGURE 6). The vertical
elongation of tab 76b is utilized at the conclusion of the
return, clockwise rotation of the operating handle 30, since
this tab swings back into engagement with drive plate shoulder
60b to establish the home positions for both the shaft and
handle. Upon arrival at their home positions, coupling element
tab 76a moves into registry with drive plate slot 60b, and
compression spring 78 then becomes effective to bodily shift
shaft 74 to its elevated position and automatically decouple
operating handle 30. A handle return spring 83 serves to
.- - . , ~. . .
~ ~ .
.
1 0 ~ 41PR-1976
insure that the handle fully returns to its home position.
A pre-shaped plate 84, seen in FIGURES 3-9, is
affixed to operating shaf~ 74 and is angularly positioned to
maintain depressed the actuator of a switch 86 throughout
the entire 120 rotational movement of the operating shaft
74 while in its elevated position. As will be seen from FIGURE
20, switch 86 is included in the control circuit for power
unit assembly 24 to enable the control circuit as long as its
actuator is depressed by plate 84 (FIGURE 7). However, when
shaft 74 is depressed to decouple power unit drive plate 60 and,
in turn, couple the manual operating handle 30 to the shaft,
plate 84 releases switch 86 (FIGURE 8), and its contacts open
to completely disable the control circuit.
As seen in FIGURE 10, the circuit breaker assembly
22 includes for each breaker pole a movable contact assembly,
generally indicated at lOQ, consisting of plural movable main
contacts lOOa individually mounted at the ends of contact
arm~ lOOb which are, in turn, pivotally mounted at their
other ends to a hinge pin lOOc. An elongated arm lOOd, also
hinged to pin lOOc, carries a movable arcing contact lOOe.
The movable main contacts lOOa and the movable arcing contact
lQOe engage stationary main contacts 102a and a stationary
arcing contact 102b when the contact assembly is pivoted to
a closed circuit position shown in phantom. Each movable
contact assembly includes a U-shaped bracket 104, also hinged
on lOOc, for coupling the contact arms lOOb and lOOd together
for movement in unison between open circuit and closed circuit
positions. The brackets 104 of the plural contact assemblies
laO are ganged together by a cross-bar 106, such that the
contact arms in all breaker poles move in concert.
An elongated hook 108, seen in FIGURE 10, is pivotally
mounted intermediate its ends by a screw 109 secured to a
bracket llQ. The lower end of this hook carries a latch
-- 10 --
10'7~ 41P~-1976
shoulder 108a for latching engagement with a pin 111 mounted
by one of the contact assemblies 100 while in its open
circuit, solid line position (FIGURE 11). As will be seen,
hook 108 is utilized to latch the movable contact assemblies
in their open circuit position while the breaker operating
mechanism is being charged either by tne power unit 24 or
rotary operating handle 30. Once the breaker operating mechanism
is fully charged, hook 108 is pivoted to its broken line
position, thereby disengaging latch shoulder 108a from pin 111
and the energy stored in the breaker operating mechanism is
thus released to abruptly pivot the movable contact assemblies
to their closed circuit position.
As seen in FIGURES 3 and 12, bracket 110 mounts an
elongated, horizontally oriented pin 112 which serves to
pivotally mount a U-shaped closing lever 114. A torsion spring
116, carried on pin 112, acts against bracket 110 to bias lever
114 for pivotal movement in the clockwise direction seen in
FIGURE 12. A roller 118 mounted adjacent the upper end of the
closing lever operates in a notch 108b (FIGURE 10) formed in
the upper end of hook 108. Closing lever 114 is held in its
cocked, counterclockwise most position of FIGURE 12 against
the urgence of its torsion spring 116 by a latch lever 120, best
seen in FIGURE 3. This latch lever is pivotally mounted
intermediate its ends on a pin 122 supported by bracket 110.
A torsion spring 124 urges the latch lever in the counter-
clockwise direction so as to position a shoulder 120a carried
adjacent one end in latching engagement with closing lever 114,
thus maintaining the latter in its cocket position.
From FIGURE 10, it is seen that with the closing
lever in its cocked position, hook 108 assumes its phantom
position with its latch shoulder 108d removed from engagement
with pin 111 carried by one of the contact assemblies 100.
.. . . . . .
4lPR-1976
~07~
Upon initial rotation of the operating shaft 74 pursuant to
charging the circuit breaker operating mechanism via either
power unit 24 or rotary operating handle 30, the leading edge
84a of an upturned mounting flange 84b by which plate 84 is
secured to the operating shaft, engages the other end 12Ob of
latch lever 120 to pivot the latch lever in the clockwise
direction (FIGURE 5), thereby releasing closing lever 114 from
its cocked position. This closing lever thus pivots in the
clockwise dlrection from the position seen in FIGURE 12 to the
position shown in FIGURE 13 and hook 108 is pivoted to its
solid line position seen in FIGURE 10, bringing its shoulder
108a into latching engagement with pin 111 of the contact assembly
100. The movable contacts are thus held by hoo~ 108 in their
open circuit positions while the breaker operating mechanism
is being charged.
Once the breaker operating mechanism is fully charged,
hook 108 is pivoted back to its broken line position of FIGURE
10 by either a closing solenoid, generally indicated at 126
(FIGURES 3 and 12) or ON button 36 (FIGURES 1 and 12) to release
the movable contact assemblies 100 for movement to their
closed circuit position. As seen in FIGURES 3, 12 and 13,
closing solenoid 126 includes a plunger 126a which carries
at its outer end a pin 126b. Closing lever 114 carries a
finger llAa positioned to engage pin 126b and pull closing
solenoid plunger 126a out to its retracted positon as the
closing lever is released from its cocked position by latch
lever 120 (FIGURE 13). After the breaker operating mechanism
has been charged, closing solenoid 126 may then be energized,
and its plunger 126a is pulled in, causing closing lever 114
to be pivoted back to its cocked position. Hook 108 is
consequently pivoted to its broken line position of FIGURE 10,
releasing the movable contact assemblies for closure.
- 12 -
1076~ 4lPR-1976
For manual closing of the circuit breaker contacts,
the ON button 36 is accommodated in a well 36a mounted by front
wall 79 of covered assembly 26 at a location above a laterally
turned flange portion 114c of an arm 114d carried by closing
lever 114 (FIGURES 3, 12 and 13). It is thus seen that
depression of ON button 36 against the bias of its return
spring 36b engages flange portion 114c to pivot the closing
lever back to its cocked position with the consequent release
of the contact assemblies 100 for closure. From FIGURE 3 it is
lQ seen that return of the closing lever to its cocked position,
either by closing solenoid 126 or ON button 36, is sustained
by latch lever 120 which is pivoted by its torsion spring 124
to bring latch shoulder 120a into engagement with the hook
actuator lever.
The pin 122, which mounts latch lever 120 as seen in
FIGURES 3 and 12, also pivotally mounts a switch actuator 130
(FIGURE 14). This switch actuator is normally biased in the
clockwise direction by torsion spring 124. An arm 130a of this
switch actuator is engaged by the end of a screw 132 adjustably
2Q threaded through an upwardly turned flange 60d carried by drive
plate 60. Arm 130a, in turn, engages the actuators 134a, 136a
of a pair of side-by-side switches 134, 136 (FIGURE 12). While
the drive plate is in its home position, the end of screw 132
engages arm 130a to pivot switch actuator 130 in the counter-
clockwise direction against the bias of spring 124, such as to
hold the respective actuators 134a and 136a of switches 134
and 136 depressed. Once drive plate 6Q moves away from its
home position during c~arging of the breaker operating mechanism
by power unit 24, the end of screw 132 releases arm 130a, and
switch actuator 130 is pivoted by its spring 124 in the
clockwise direction, releasing the switch actuators. When drive
plate 60 is returned to its home position at the conclusion of
- 13 -
41PR-1976
an operating mechanism charging cycle, the switch actuator 130
is reengaged by the end of screw 132, and the actuators of
switches 134 and 136 are again depressed. The functions
of these switches will be described below in connection with
the circuit diagram of the power unit control circuit.
To identify the condition of the circuit breaker 20,
an indicator mechanism, generally indicated at 140 in FIGURE
15, is provided. This indicator mechanism includes a display
panel 142 having different display segments which are
individually viewable through window 32 (FIGURE 1) provided in
the front wall of cover assembly housing. As seen in FIGURES
16 through 19, one display segment of the display panel bears
the indicia "OFF" which, when viewable through window 32,
identifiers that the breaker contacts are in their open circuit
conditions. A second display segment of display panel 142
bears the indicia "CHG" which, when viewable through window 32,
identifies that the breaker operating mechanism is fully
charged, but the breaker contacts are latched in their open
circuit position by hook 108. The third display segment of
panel 142 bears the indicia "ON" which, when viewable through
window 32, identifies that the breaker contacts are closed.
Display panel 142 is carried by an indicator arm 144
pivotally mounted on a pin 146 which is supported by a
depending portion 110a of bracket 110 (FIGURE 12). Also
pivotally mounted on pin 146 is a first control lever 148 and
a second control lever 150. Control lever 148 is provided with
a laterally turned tab 148a, while indicator arm 144 is
provided with a laterally turned tab 144a; these tabs serving
as anchor points for the ends of a tension spring 152. This
spring serves to bias indicator arm 144 in a counterclockwise
direction such that a second tab 144b turned from indicator arm
144 abuts control lever tab 148a while these elements are in
- 14 -
.. . . . . . .
41PR-1976
107~
their positions illustrated in FIGURES 15 and 16.
A torsion spring 154, mounted on pivot pin 146, has
one end engaging a tab 148b struck from control lever 148 such
that this control lever is biased in the clockwise direction
with an edge portion 148c thereof abutting a stop 66a provided
by the floor 66 of the power unit housing. The other end of
torsion spring 154 acts against a laterally turned tab 150a
carried by the second control lever 150, so as to bias this
plate in the counterclockwise direction which, in the positions
shown in FIGURES 15 and 16, ~rings an edge portion 150b of
this plate into engagement with a pin 156 carried at the upper
end of a lever 158. This latter lever is pivotally mounted on
a shaft 160a on which is keyed a cradle 160 included as part
of the breaker operating mechanism disclosed in the above
identified Canadian application. The lower end of lever 158 is
forked to provide a deep, bottom opening notch 158a in which is
received the other end of pin 111 carried by one of the movable
contact assemblies 100 (FIGURE 10). Thus, lever 158 is
responsive to the position of the movable contact assemblies
such that it assumed its solid line position shown in FIGURE 15
when the contact assemblies are in their open circuit position
and its broken line position when the contact assemblies are
in their closed circuit position. With lever 158 at its
solid line position, roller 156 at its upper end is in position
to hold control lever 150 in its most clockwise position
against the urgence of spring 154. On the other hand, when
the contacts close, lever 158 is pivoted to its broken line
position of FIGURE 15, and control lever 150 is freed to move
in the counterclockwise direction until a tab 150c extending
3Q: from the upper corner of this lever engages the upper surface
of stop 66a, as seen in FIGURE 19.
Control lever 148 is acted upon by an arm 164 pinned to
- 15 -
- . . .. . .
4lPR-1976
iO7~
cradle shaft 160a. As seen from the above-noted Canadian
application, as the breaker operating mechanism is being charged,
the cradle is swung around from its tripped position, seen
in solid line in FIGURE 15, to a phantom position where it can
be latchably engaged by a primary latch 165. Arm 164 follows
this movement of cradle 160, and in so doing, engages a laterally
turned tab 148d of control lever 148, pivoting this lever in
the counterclockwise direction from its position shown in
FIGURE 15 to its position shown in FIGURE 17. As long as
cradle 160 is latchably engaged by primary latch 166, arm 164
holds control lever in its most counterclockwise position of
FIGURE 17.
From the description thus far it is seen that control
lever 148 is responsive to the position of cradle 160 of the
circuit breaker operating mechanism, while control lever 150 is
responsive to the position of the movable contact assemblies
100. As will be seen from FIGURES 16 through 19, these control
levers function in conjunction with a prop lever 170, best seen
in FIGURE 3, to control the angular position of indicator arm
144 such as to register the appropriate display segment of
display panel 142 with window 32. Referring jointly to FIGURES
3 and 15, lever 170 is pivotally mounted on a pin 172 and is
normally biased by a torsion spring 174 acting against a fixed
stop 176 to bias the prop lever in the clockwise direction.
Lever 170 is provided with an angularly turned free end portion
170a which projects into a position of engagement with the
trailing edge 84c of upturned mounting flange 34b for plate 84.
With plate 84 in its home position seen in FIGURE 3, prop lever
170 is held by trailing edge 84c in its most counterclockwise
position against the bias of spring 174. In this position, the
lower left hand corner 170b of this lever is swung to the right
in non-interfering relation with the portion of indicator arm
- 16 -
iO 7 6 6~ 41PR-1976
144 below its upper offset portion 144c to which display panel
142 is joined. However, during a charging operation, rotation
of plate 84 with operating shaft 74 causes its trailing edge
84c to gradually release the prop lever as it progresses along
an arcuate cam surface 170c of the prop lever. As a con-
sequence, spring 174 ultimately moves prop lever 170 to its
most clockwise position defined by pin 176 engaged in the
enlarged opening 170d in the prop lever. In this most clockwise
position, the corner 170b of prop lever is moved to the left
into the path of counterclockwise movement of indicator arm 144.
As cradle 16Q is being reset to its latch position
(phantom position in FIGURE 15) during a charging cycle, arm
164 fast to the cradle shaft 160a, is swung in the cloc]cwise
direction into engagement with tab 148d of control lever 148.
During the concluding resetting movement of the cradle, arm
164 pivots control plate 148 to its most counterclockwise
position shown in FIGURE 17. Spring 152 connected between
control lever 148 and indicator arm 144 is tensioned such as
to bias indicator arm 144 for counterclockwise rotation a~out
2Q its pivot pin 146. However, until the charging cycle is fully
completed, prop lever 174 is in its most clockwise position,
and thus its corner 170b obstructs movement of the indicator
arm by tension spring 152. However, at the conclusion of
the charging cycle, the trailing edge 84c of plate 84 is in
its position seen in FIGURE 3 to cam prop lever 170 back to
its most counterclockwise position, clearing the corner 170b
from obstructing the movement of indicator arm 144. Thus, as
seen in FIGURE 18, indicator arm 144 is free to move under
the urgence of spring 152 to a position where its tab 144b
engages a laterally turned tab 150d carried by control lever
150 which has yet to move. This limited pivotal movement of
indicator arm 144 is effective to shift the display segment of
- 17 -
4lPR-1976
107~i~Z~
display panel 142 bearing the indicia "CHG" into registry with
window 32.
Upon disengagement of the hook 108 ~rom contact
assembly pin 111, either by closing solenoid 126 or depression
of O~ button 36, the movable contacts spring to their closed
circuit position, and lever 158 is shifted to its broken line
position seen in FIGURE 15. Roller 156 carried by this lever
is no longer in pcsition to hold control lever 150 in its most
clockwise position, and thus it is pivoted by its spring 154 to
its most counterclockwise position seen in FIGURE 18 with tab
150c engaging stop 66a. Indicator arm 144 is thus released
for an additional increment of counterclockwise pivotal movement
under the urgence of spring 152 until the edge of the indicator
arm engages a shoulder 170f formed in prop lever 170 (FIGURE 3).
In this most counterclockwise angular orientation of the
indicator arm, the display segment of display panel 142 bearing
the indicia "ON" is registered with window 32.
It will be appreciated that upon tripping of the
circuit breaker, cradle 160 abruptly swings around to its
tripped position, carrying with it arm 164. Control lever
148 is thus released, and spring 154 pivots it around to its
most clockwise position with edge 148c engaging stop 66a. During
this clockwise movement of control lever 148, its tab 148a
engages tab 144b to pick up the indicator arm for clockwise
movement terminated by the engagement of its edge portion 144d
with stop 66a. With the release of cradle 160, the breaker
operating mechanism proceeds to open the breaker contacts.
Lever 158 follows this opening movement in swinging to its
solid line position seen in FIGURE 15. The pin 156 carried
at its upper end engages edge 150b to cam control lever 150
around in the clockwise direction to its ~lid line position
seen in FIGURE 15.
- 18 -
iO7~ 41PR-1976
In addition to controlling the angular position of
indicator arm 144, control levers 14~ and 150 are provided
with actuating tips 148e and 150e, respectively, which are
effective to control the conditions of a pair of side-by-side
switches 180 and 182 (see also FIGURE 3). It is seen from
FIGURE 15, that while the control levers 148 and 150 are in
their most clockwise positions assumed while the circuit
breaker is in its OFF condition, their switch actuating tips
148d and 150d are in disengaging relation with their
respective switches 180 and 182. When control lever 148 is
shifted to its most counterclockwise position by arm 164,
its tip 148e actuates switch 180 to signal to the power unit
control circuit logic that cradle 160 is in its latched
position. Similarly, when control lever 150 is shifted
to its most counterclockwise position by spring 154 upon
release by pin 156 carried by lever 158, its tip 150e
actuates switch 182, signaling the power unit control
circuit logic that the breaker contacts are closed.
~ simplified schematic diagram of the power unit
electrical control circuit is seen in FIGURE 20. It will be
appreciated that, in practice, the circuit will include
additional electrical components to provide appropriate arc
suppression, transient suppression and voltage flyback
suppression. The control circuit is shown energized from
a D.C. source however, in many installations, the control
circuit will be energized from an A.C. source, and in this
event, appropriate rectification is provided. Referring now
to the circuit diagram, the positive side of the D.C. source
is applied to terminal 200, while the negative side is
applied to terminal 202. Terminal 200 is connected through
the normally closed switches 86 and 182 the closed contacts
180a, 180b of switch 180 to terminal 204. A terminal 206
is connected through the operating coil 208 of a relay,
-- 19 --
.
41PR-1976
1~7~
generally indicated at 210, a resistor Rl, and a
Zener diode Dl to negative terminal 202. Terminals 204 and
206 are shunted by the normally open switch 136. Contact
180c of switch 180 is connected through the normally closed
switch 134 to a terminal 212, while a terminal 214 is
connected through the closing solenoid coil 126 to negative
terminal 202. Terminals 200, 202, 204, 206, 212 and 214
are provided on terminal board 28 of FIGURE 1. Positive
supply terminal 200 is also connected to normally open contact
210a or relay 210. The movable contact 210b of this relay
is connected to one side of the permanent magnet D.C. motor
40, while the other side of this motor is connected to the
negative supply terminal 202. Relay contact 210b normally
engages relay contact 210c which is connected through a braking
resistor R2 to the other side of motor 40.
The operation of the electrical control circuit of
FIGURE 20 will now be described. To initiate a charging
function by motor 40, terminals 204 and 206 are shorted
together, as functionally indicated at 205. It is seen that
2Q current can thus flow through the normally closed switches
182 and 86, the closed contacts 180a and 180b of switch 180,
relay coil 208, resistor Rl and Zener diode Dl to the
negative supply terminal 202. Resistors Rl and Zener diode
Dl are selected so as to provide the desired pickup and drop
out characteristics for relay 210. Energization of relay
coil 208 causes its movable contact 21Qb to break with
contact 210c and make with contact 210a. As a result, a
D.C. energization circuit for motor 40 is completed between
terminals 20a and 202. Referring to FIGURE 3, motor 40
begins charging the breaker operating mechanism by rotating
drive plate 60 which is coupled to operating shaft 74. As
the drive plate moves away from its home position in the
- 20 - -
.
41PR-1976
1~,6~
counterclockwise direction, the end of adjusting screw 132
releases switch actuator lever 130 which, in turn, releases
switches 134 and 136. Referring back to the wiring diagram,
it is seen that switch 136 closes to provide a current path
shunting terminals 204 and 206. Thus, the short 205 applied
to initiate a charging function can be removed, as the now
closed switch 136 seals in the energization circuit for
relay coil 208. This continued energization of the relay coil
seals in its contacts 210a and 210b to insure continued
energization of the motor 40 for the complete charging cycle.
Upon completion of 120 of counterclockwise
rotation of drive plate 60, operating shaft 74 will have
been driven through a like increment of counterclockwise
rotation. Slide 72 will have thus completed its forward stroke
and cradle 160 will have arrived at its position of latching
engagement with primary latch 166. As a consequence, arm
164 , keyed to cradle shaft 160a, will have been rotated in
the clockwise direction as seen in FIGURE 15 to pivot control
lever 148 in the clockwise direction such that its tip 148e
2Q actuates switch 180. Referring back to the wiring diagram,
it is seen that upon actuating of switch 180, its contact
180a is shifted from engagement with contact 180b to
engagement with contact 180c. Upon the arrival of drive
plate 60 back to its home position to complete the charging
cycle, the end of adjusting screw re-engages switch actuator
130 which, in turn, re-engages switches 134 and 136. Switch
134 thus returns to its normally closed condition, while
switch 136 is returned to its normally open position breaking
the energization circuit for relay coil 208. As this relay
3Q drops out, its movable contact 210b disengages from contact
210a and engages its contact 210c to connect the braking
resistor R2 in shunt with motor 40. The energization circuit
- 21 -
41PR-1976
1076~
for the motor is broken and the braking resistor is
effective to abruptly brake the motor to a stop, leaving
the drive plate 60 precisely in its home position. Rotation
of the adjusting screw ]32 provides for fine adjustment
of the angular orientation of the drive plate home position.
At the conclusion of the charging cycle, it is seen
from the wiring diagram that switches 86 and 182 remain
closed, while switch 134 is reclosed and switch 136 is re-
opened. Switch 180 has assumed its condition wherein movable
contact 180a is engaging contact 180c. These switch
conditions serve to prevent a re-initiation of the charging
cycle, a needless act since the mechanism is already charged,
and to arm the energization circuit for closing solenoid 126.
To close the breaker contacts by energization of
the closing solenoid, terminals 212 and 214 are shorted
together, as functionally indicated at 213, to connect the
closing solenoid coil 126 directly across the D.C. supply
terminals 200, 202. Hook 108 is disengaged from the contact
carrier assembly, and the breaker contacts close (FIGURE 10).
Movement of lever 158 to its broken line position seen in
FIGURE 15, causes pin 156 to release control lever 15Q. This
control lever is thus freed for counterclockwise rotation by
its spring 154 bringing its tip 150e into actuating engagement
with switch 182. Switch 182 opens to disable the control
circuit from accommodating either a charging function or a
contact closing function. The circuit is then completely
inoperative until such time as the breaker contacts are
reopened.
The normally closed switch 86 in the control
circuit functions, as previously noted, as an interlock to
completely disable the control circuit in the event the
operating mechanism is being charged manually. As seen from
- 22 -
4lPR-1976
iO7f~
FIGURES 7 and 8, when button 31 is depressed to shift operating
shaft 74 downward and couple the rotary handle 30 to the
operating shaft, plate 84 releases switch 86 which opens to
prevent inadvertent energization of motor 40. Once a manual
charging cycle is completed, compression spring 78 returns
operating shaft 74 to its elevated position, and plate 84 re-
actuates switch 86 6O its closed condition. Consequently,
even though the circuit breaker operating mechanism was manually
charged, the control circuit of FIGURE 20 will accommodate
closure of the circuit breaker via energization of closing
solenoid 126. Alternatively, closure of the breaker
contacts can be effected by manual depression of ON button 36.
As an additional feature of the present invention,
switch 182 is also utilized to serve an anti-pumping
function. If for some reason, the breaker latch 166 is held
in its non-latching position, such as by a breaker lockout
accessory, the initiation of a charging cycle is useless since
the cradle will simply return to its unlatched position at
the conclusion of the charging cycle. In certain automated
system applications, failure of the cradle to be latched at
the conclusion of a charging cycle will simply signal a
re-initiation of another charging cycle. To prevent this
needless pumping of the breaker operating mechanism, a lever
220 is mounted on a pin 222 with one end 220a situated to
engage switch 182, as seen in FIGURE 21. The other end
220b of this lever also seen in FIGURE 3, is disposed to
engage a tandem OFF button 223 which is reciprocatingly
mounted by the power unit housing floor 66 in registry under
the OFF button 34 reciprocatingly mounted by the cover
assembly front wall 79. Thusr manual depression of button
34 causes its depending stem 34a to depress button 223, whose
lower end engages and pivots latch 166 to its non-latching
- 23 -
4lPR-1976
107~
osition. A light spring 224 biases the lever in the clockwise
direction, such that the lever end 220b biases tandem OFF
button 223 downward to sustain its engagement with latch 166.
Thus lever 220 senses the vertical position of button 223
which is indicative of the position of latch 166. If the
breaker latch is held in its non-latching position, tandem
OFF button 223 will assume a depressed position under the bias
of lever spring 224 independently of OFF button 34. Lever
22n will, in sensing this depressed position of button 223,
assume its most clockwise position, bringing its end 220a into
actuating engagement with switch 182. This switch thus
opens to inhibit initiation of a charging cycle, as seen in
FIGUP~E 20. It is thus seen that as long as the breaker
latch is held in its non-latching position, switch 182 is
engaged and held in its open position, thereby accomplishing
its anti-pumping function. It is understood that when the
breaker latch 166 is released, its spring (not shown) over-
powers lever spring 224 in returning the latch to its latching
position. Lever 220 is returned to its most counterclockwise
position and switch 182 is released for closure toenable a
charging cycle.
Referring jointly to FIGU~ES 3 and 12, a safety
interlock lever 230 is pivotally mounted intermediate its
ends by a pin 232 supported by bracket 110 (FIGURE 12). A
strong spring 234 normally biases this lever such that its
end 230a engages and depresses tandem OFF button 223
(FIGURE 3), thereby tripping the breaker if it is closed
and holding the breaker latch in its non-latching position
to prevent subsequent reclosure of the breaker. The other
end 230b of this lever is engaged and depressed by the
cover assembly housing, when in place, to hold the lever
end 230a in disengaged relation with tandem OFF button 223.
- 24 -
4lPR-1976
107~
This button may then assume its elevated position, thus
removinq its disablement breaker latch 166. It is thus
seen that as long as the cover assembly 26 is in place,
circuit breaker 20 can be operated in normal fashion via
the handle 30 or the power unit 24. However, upon removal
of the cover assembly 26, lever 23~ is released and its
spring pivots this lever into depressing engagement with the
tandem OFF button 223 to automatically trip the breaker if
the breaker is still in its ON condition. Continued
depression of button 223 by lever 230 as long as the cover
assembly is displaced, prevents o~eration of the breaker.
It will thus be seen that the objects set forth
above, among those made apparent in the preceding description,
are efficiently attained ar.d, since certain changes may be
made in the above construction without departing from the
scope o, the invention, it is intended that all matter
contained in the above description or shown in the accompanying
drawings shall be interpreted as illustrative and not in a
limiting sense.
- 25 -
