Note: Descriptions are shown in the official language in which they were submitted.
5754
This invention relates to an electrical circuit breaker
in which the contacts open during overload with a snap action
and when manually operated by the circuit breaker handle are
both opened and closed with a snap action. More particularly,
the invention is directed to a simplified more compact and
improved circuit breaker of this type incorporating an over-
load current coil and armature tripping mechanism.
A snap action circuit breaker is disclosed in assignee's
U S. Patent No. 3,806,848. In this device a toggle mechanism
0 i5 trippea by the attraction of an armature to an electro-
magnet when the current through the electromagnet coil exceeds
a predetermined value. Coupled to the movable contact of the
circuit breaker is an over center spring so that upon tripping,
the contacts open with a positive snap action to minimize
contact-arcing.
The over center spring also acts on the movable contact
when the contacts of the circuit brea~er are opened or closed
-~ by way of the toggle handle. ~his snap action opening and
closing of the circuit breaker contacts during manual operation
has the advantage that it makes it impossible for anyone to
"tease" the contacts in such a way as to damage the circuit
breaker. - -
The present invention is directed to a snap action circuit
bxeaker of this general type hut one which is of simplified,
more compact construction, is more attractive in appearance,
and one which may be utilized with a variety of different
handle cons~ructions. The circuit breaker of the present in-
vention is particularly constructed to be small and more pleas-
ing in appearance so that it may be used in more visible locations
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such as on instrument panels and the like, and since it
opens and closes during manual operation with a snap action,
it may be manually operated much in the manner of a conven-
tional electrical switch. It is designed to combine aspects
of conventional electrical switch operation with electromag-
netic type of current protection.
~his is brought about by utiliziny a novel, one piece
frame construction for the operating mechanism in combination
with a single basic symmetrical case and linkage assembly
compatible with a variety o~ operating handles. The sym-
metrical construction provides a pleasing appearance as does
the availability of various operating handles. Additionally,
different handle constructions may give different manual
motions to the linkage mechanism such as conv~ntional two
position on-off or a push to open, push to close actuated
operation.
It is therefore, an object of the present invention
to provide an improved snap action circuit breaker.
In accordance with a broad aspect, the invention
relates to a circuit breaker, comprising an insulated
housing; an overcurrent sensor located in said housing,
a stationary contact in said housing; a latch meahanism
engageable by said overcurrent sensor and adapted to be
tripped by said sensor in response to a sensed overcurrent;
a movable carried coupled to said latch mechanism and
movable between closed and open positions into and out of
contact with said stationary contact in response to move-
ment of said carrier; and an overcenter spring coupled to
said movable contact for opening and closing said contacts
with a snap action; said breaker being characterized by:
a frame located in said insulated housing and having a
unitary structure, including:
a central strap having an outwardly ~ent tab at
one end for msunting said overcurrent sensor, and a pair
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- of substantially aligned side plates integral with and
extending from oposite lateral sides of said strap, said
side plates having first aligned openings for receiving
spring mounting means for securing said overcurrent spring
to said frameand second aligned openings for receiving said
movable carrier for pivotal movement of said carrier between
said first and second positions.
These and further objects and advan~ages of the invention
will be more apparent u~on reference to the following specifi-
cation, claims and appended drawings wherein
Figure l is a side elevation of a circuit ~reaker
constructed in accordance with the present invention and
~; incorporating a toggle type handle.
Figure 2 is a view showing principal portions of the
internal operating mechanism of the circuit breaker of Figure 1
with the contacts in the manual open position.
Figure 3 is an end view showing the structure of
Figure 2.
Figure 4 is a view similar to Figure 2 showing the
circuit breaker contacts in the manually closed position.
Figure 5 is a view similar to Figures 2 and 4 showing
the circuit breaker mechanism when the contacts are in the
tripped open position.
Figure 6 is a perspective view of the over center
spring assembly for the movable contact which produces the
snap action.
Figure 7 is a perspective view of the latch mechanism
of the circuit breaker.
Figure 8 is a side view of the cam link forming a
portion of the latch mechanism of Figure 7.
Figure 9 is an edge view of the cam link of Figure 8.
Figure lO is a side view of the housing link forming
the othex collapsible link of the mechanism of Figure 7.
Figure ll is a slde edge view of the housing link of
Figure 10.
Figure 12 is a view of the housing link taken from the
side opposite to that of Figu~e lO.
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~ 5754
Figure 13 is a top edge view of the housing link of
Figures 10 through 12.
Figure 14 is a side view of the handle link forming a
part of the mechanism of Figures 2 through 5.
Figure 15 is an end view of the handle link of-Figure
14.
Figure 16 is a side view of the one piece frame forming
a major component of the mechanism illustrated in Figures 2
through 5.
o Figure 17 is a side edge view of the frame of Figure 16.
Figure 18 is a top edge view of the fxame.
Figure 19 is a si~e view of the armature illustrated in
Figures 2 through 5.
Figure 20 is a front view o the armature of Figure 19.
Figure 21 is a partial top view of the armature.
Figure 22 is a view of the armature from the other side
relative to ~igure 19.
Figure 23 is a ~ront view with a portion in section of the
circuit breaker of Figure 1 showi~g the manual ~oggle construc-
~0 tion,
Figure 24 is a partial cross section at right angles to
the view of Figure 23, again ~howing the toggle handle operating
- mechanism.
~igure 25 i5 an exploded view of ~he toggle handle embodi-
~5 ment o~ the present invention illustrating how some of the parts
it together.
Figure 26 is a front elevation ~f the lower portion of the
circuit breaker case incorporating the circuit breaker terminal.
Figure 27 is an end view of the lower case section of
~30 Figure 26~
Figure 28 is a partial front elevation of a modiiied circuit
breaker case constructed in accordance with the present invention
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and inc~rporating a rocker type handle.
Figure 29 is a partial cross section through the modified
construction of Figure 28 showing the manner of connecting the
rocker handle to the handle link.
Figure 30 is a partial cross section taken ~long lines
30-30 of Figure 29.
Figure 31 is a front plan view of a lamp bracket forming
a part of the structure of Figures 29 and 30.
Figure 3~ is an end view of the lamp bracket of Figure 31.
~igure 33 is a top plan view of the lamp bracket of
Figure 31.
Figure 34 is a partial cross section showing a step in
the process of attaching the rockex handle to the circuit breaker.
case.
~igure 35 is a view similar to Figure 34 showing the rocker
handle mounted in the case and engaging a handle link.
Figure 36 is a front eleYation of a further modified
embodiment in accordance with the present invention showing a
push button type handle for the circuit breaker.
Figure 37 is a front elevation with a par~ in section show-
ing the handle link in the "on" position.
Figure 38 is a view similar to F}gure 37 showing the handle
link in the "off" position.
Figure 39 is a front elevation of the push button type
handle of the embodiment of Figure 36.
Figure 4D is a bottom plan view of the handle of Figure 39.
Figure 41 is a front view of the handle illustrating the
engagement of the actuator blade of the handle with a handle link.
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,
Figure 42 is a front elevation of the spring support for
the spring forming a part of the handle illustrated in Fi~ures
39 through 41.
~ igure 43 is a ~ottom plan view of the spring support of
Figure 42.
Fi~ure 43A is a cross section taken along the line 43A-43A
of Figure 43.
Figure 44 is an enlarged front view of the actuator blade
~hown as part of the assembl~ in ~igure 41.
Figure 45 is an enlarged side view of the actuator blade
of Figure 44.
Figure 46 is a cross section through the center of the
push button of the embodiment of ~igure 36.
~: Figure 47 is a bottom plan view of the push button of
Figure 46.
Figure 48 is a diagrammatic view illustrating a step in
the assembly of the push button with the circuit breaker case
and,
-~ Figure 49 is an exploded view showing th~ electrical lamp
connections for the lamp carried in the push ~utton of the
embodiment of Figure 36.
Referring to the drawings~the novel circuit breaker of
the present invention is generally indicated at 10 in Figure 1.
- The circuit breaker comprises a ease 12 of molded electrically
insulated plastic which is formed of an upper or outer case
section 14 which is open at its lower end to receive a lower
portion or lower case section 16. Lower section 16 carries
a pair of electrically conductive terminals 18 and ?0 and has
two projections on each side,=uch as the projections 22 and 24,
which are receiv~d in corresponding slots 26 and 28 in upper
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casing section 14. The upper section has two grooves on each
side such as the grooves 30 and32 to impart more flexibility
to the upper section so that the lower section may be slipped
into it until the projections 22 and 24 snap into the slots
26 and 28. Upper case section 14 includes a boss 32 from which
extends a toggle type circuit breaker handle 34.
Figure 2 is a side view showing the lower case half 16 ana
the circuit breaker trip mechanism generally indicated at 36
and illustrated in Figure 2 in the manually open position.
~igure 3 is a cross section of the mechanism of Figure 2 taken
at right angles to it., Figure 4 is a view similar to Figure 2
with the ¢ontacts in the manually closed posit;on and Figure 5
is a similar view of ~he mechanism when the contacts have been
tripped open by an over current. The construction is of the
lS same general type as that disclosed in assignee's U.S. Patent
3,U06,g48 but is signi~icantly improved to provide a more
compact and symmetrical operating mechanism construction.
Referring to Figure 2, the mechanism 36 comprises a one
piece frame 38 (shown in detail in Figures 16 through 18) upon
which is mounted an over current trip coil 40. The coil is
.csnnec~ed to a terminal 18 by way of an electrical lead 42 and
surrounds a delay fube 44 terminating in a pole piece 46 which
is positioned adjacent one end of an arma~ure 48 pivoted about
a pin 50 secured to the frame 38.
Also pivoted to the frame by a pin 52, is a handle link 54
pivoted by a pin 56 at its lower end to a cam link 58. The cam
link 58 connects to a second pivotal link by a pin 60 which second
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35~S4~ i
pivotal link is generally referred to as a housing link and is
indicated at 62. ~rmature 48 at its other end on one side,
carries an enlarged portion 64 which forms a counterweight
for the end near the pole piece 46 and on its other side, carries
a curved projection 66 adapted to engage and rota~e a sear 68
which p~rmits the cam link 58 and housing link 62 to collapse
xelative to each other under the influence of a blade spring.
Contact terminal 20 is connected with a stationary contact
70 which completes a circuit through the tWo terminals 18 and 20
o by way of a movable contact 72 mounted on and carried by a blade
74. 81ade 74 is acted on by an over center spring 76 to have
a snap opening and snap closing operation, the other end of the
spring being wrapped around a pin 78 secured to the frame. The
other end ~f blade 74, as more fully described below, is pivoted
.5 to a ~lade carrier 80, which is pivoted by a pin 82 to the lower
end of housing link 62. The two links, namely, the cam link 58
and the housing link 62 with the cooperating sear 68 are generally
referred to as the latch mechanism. The electrical circuit is
completed from the movable contact 72 by way of ~he blade and
blade carrier, a braided wire 8 4 and a lead 8 6 to the other si~e
o~ the coilO
~igure 4 shows ~he mechanism moved to the contacts "closed"
~ position with the handle link 54 having its upper end moved in
;~ a clockwise direction from the position illustrated in Figure 2.~25 This link acts through the latch mechanism previously described
to bring movable contact 72 into engagement with stationary
contact 70 to complete the circuit between te~minals 18 and 20.
Handle link 54 is rotated by a handle, as more fully described
belo~, acting on hand~e link pin 88.
,
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5754 1 )
Figure 5 shows the circuit breaker in the tripped open
position. The latch mechanism has been collapsed by engagement
of the end 66 of the armature with the sear trip bar 68. ~ver
center sprin~ 76 has caused.the contac.t 72 to move away from
contact 70. Figure 5 illustrates the latch mechanism in the
"trip free" position, that is, the cor.tacts have opened due
to an overload while the handle link i5 manually xestrained
in the closed position illustrated, which it assumed in-~igure 4.
The armature has returned under the influence of an armature
spring (not shown) to a position spaced from the pole piece 46.
By manually moving the handle link 54 from the position illus-
trated in Fig. 5 to the position illustrated in Figure 2, the
unit becomes completely reset and ready fox operation if the
fault has been removed.
Figure 6 is an enlaryed perspective view of the over
current contact blade assembly. Blade carrier 80 has a turned
~ over end 90 with a tapered groove 92 receiving a ~nife edge at
: 94 ~f the blade 74 so tha~ blade 74 pivots in groove 92. Turned
over end 90 is an integral part of and extends downwardly from
a flat top plate 802. A pair of upturned tabs 804 and 806
are formed from the opposite end portion of top plate 802. A
pair of side plates 808 and 810 extend do~nwardly from opposite
sides of the top plate 802. A pair of pivot mounting tabs
~only tab 812 being shown in Fig. 6~ are formed from the
forward bottom parts o side plates 808 and 810~ Spring 76
has one end 96 wrapped around the pin 78 and its other end
received throu~h an aperture in the blade 74. The operation
of the blade and blade car~ier is essentially the same as in
U,S, Patent 3,806,848 and will not ~e descri~ed in urther
detail.
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~3S7S4 ( '
Figure 7 is a perspective view of the collap~ible latch
mechanism. It comprises the cam link 58 and the housing link 62.
pivoted to each other by a pin 60. When the end 66 of the
armature, as illustrated in Figure 2, hits the trip bar,
commonly called the striker bar 68, it moves this bar causing
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~ ~L3~;75~ ,
a sear pin 98, mounted in the two sides of housing link 62,
to rotate. Sear pin 98 has a central portion cut away to form
a-se~.i-circular cross section and when it is rotated it releases
the cam link and permits it to rotate in the direction of the
arrow 100 about pin 60 relative to the housing link 62 produc-
ing mechanism collapse.
Figure 8 is a side view and Figure 9 is a front edge YieW
of the cam link 58. It is pxovided with upper and lower aper-
tures 102 and 104 adapted to receive respectiv~ pivot pins,
with a first cam surface 108 adapted to bear against the sear
pin 98 before it is rotated and a second cam surface 106 which
along with the identical surface of the opposite side of the
cam link, engages the slot in the sear pin 98. This prevents
excessive lateral movement of the sear pin and thereby keeps it
captive in the housing link, both in the latched position and when
the cam link is rotated in a counterclockwise direc~ion indicated
by the arrow 100 in Figure 7.
Figure 10 is a side view and Figure 11 is a front view
of the housing link 62 forming a part of the toggle mechanism of
Figure 7~ Figure 12 is a view of the housing lin~ 62 from the
opposite side and Figure 12 is a bottom plan view~ It comprises
a pair of parallel spaced plates llQ and 112 joined by a pair of -
integral straps 114 and 116 and with respective upper apertures 118
and 120 and respective l~wer apertures 122 and 124 for appropriate
pivot pins. Formed in the parallel projections 126 and 128 are
the apertures 120 and 132 for receiving the sear pin. Tab 134
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~13~7~
acts as a stop for striker bar 68 in Figure 7.
Fi~ure 14 is a side ~iew of the handle link 54 and Figure 15
is an edge view. The handle link ~gain comprises what is sub-
stantially a pair of parallel plates 136 and 138 with respective
upper pivot apertures 140 and 142 and lower respective pivot
apertures 144 and 146. The two plates are joined by a central
portion 148 in Figure 15 and with a laterally extending boss
150 having a central aperture 152 adapted to receive a pivot
pin which secures the handle link to the frame as indicated,
.0 $or example, at 52 in Figure 2.
Figure 16 is a side view of the one piece frame as it is
shown in Figure 2. Figure 17 is an edge view and Figure 18 is
a top plan view of the one piece frame. Again, the frame com-
prises essentially, a pair of parallel plates 154 and 156 joined
.5 by a central strap 158 having a projection 160 at its upper end
ana an outwardly bent tab 162 at its lower end, which tab supports
the coil 40 in Figure 2. This tab is apertured at 164 to receive
the lower end of the delay tube 44 in Figure 2. The two plates,
154 and 156 of the frame have corresponding apertures 166 and
168 adapted to receive the pivot pin 50 of Figure 2 which pivots
, the armature to the frame. ~bove these are further correspond-
: ing apertures 170 and 172 which receive the pivot pin 52 of
Figure 2 about which the handle link 54 rotates or pivots. An
outward projection on plate 38 indicated at 174 in Figures 16
and 18 is provided with an aperture 176 adapted to rotatably
.~ receive an inertia wheel of the type illustrated particularly
in Figures 10 and 11 of assignee's U.S. patent 3,497,838. This
inertia wheel is operated by the counterweight portion 64 of the
armature through a slot and pin coupling of the type disclosed
in that patent. The inertia wheel construction is optional in
~3S75~
the circuit breaker of the present invention and i5 normally
only incorporated in those devices used in situations where
nuisance tripping is a serious problem. The lower end of
each plate 154 and 156 is notched as indicated at 178 in
Figure 16 to engage a projection on the molded circuit breaker
case such as that indicated at 180 in Figure 2 to properly
position and align the frame in the case.
The forward face o~ each side plate 154 and 156 is
provided with a part circular opening or no~ch 157 to receive
tab 812 of the carrier 80 to permit pivotal movement of the
carrier 80 against frame side plates 154 and 156. The rear
face of each side plate 154 and 156 is provided with a part
circulæ opening or notch 159 to receive the overcenter spring
support pin 78. As seen in Fig. 16, the center of opening 157
is located below that of opening 159 to permit proper snap action
~pening and closing of contacts 70 and 72.
Figure 19 is a side ~iew of the armature generally
indicated at 180. Figure 20 is a front view of the entire
armature, Figure 21 is a partial ~op plan view and Figure 22
is a view from the other side showing the other leg of the
armature, while the position of the armature in Figure 19
corresponds to the position illustrated, for example, in
Figure 2. The latch tripping leg extends downwardly and
terminates in a curved end 182 and this leg is provided with
a pivot aperture 184. The other leg of the armature forming
the counterweight 64 has a corre~ponding pivot aperture 186
and includes an eIongated slot 18B near its lower end adapted
to engage a pin on an inertial wheel to form an inertial delay
coupling o~ the type ~hown in assi~nee's patent 3,497,838 as
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previously described. In the device of ~his invention, the slot
188 is formed in that portion of the armature removed as far as
possible from the pivot aperture 186. This makes it possible
to form the frame 38 out of a single piece of relatively inexpen-
~ive magnetic material, such as steel. This permits the inertial
wheel to operate in the manner described in the above patent to
provide an inertial tripping delay to the armature which is in
addition to the tripping delay provided by the delay tube 44.
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~3575~ ~
Figure 23 is a view similar to Figure l with parts in section,
illustrating how the toggle handle 34 is connected to the handle
link pin 88. Figure 24 is a partial cross section through the
circuit breaker 10 of Figure 23 taken at right angles to the
view in the previous figure. The assembly technique is somewhat
similar to that illustrated in Figures 1 through 3 of assigneels
U.S. Patent 3,749,873. Similar to that arrangement, the boss
32 of the molded case, is provided with a pair of cooperating
circular projections 190 and 192, which snap in to corresponding
recesses 194 and 196 in the sides of toggle handle 34. ~hese
recesses are continuous with grooves 198 at 200. The pins sn~p
into the recesses by snapping by the projections 202 and 204
on each side, best seen for example, in the exploded view of
Figure 25, which have sufficient resiliency to open slightly
to permit passage of t~e corresponding round projection and then
closes sufficiently to hold the handle relative to the case~
The toggle handle ~4 carries a central por~ion in the form
of an actuator 206 which has a slot 208 in its lower end which
slides over and engages the handle link pin 8B carried by the
handle link 5~. In order to insert the toggle handle, the
mecha~ism, during assembly,is placed in the manually open position
illustrated in Figure 2 with the handle link 88 in the position
illustra~ed in Figure 2~ which is also the position in which it .
. is sho~m in Figures 23 through 25. The toggle handle 34 is then
tilted in a slightly clockwise direction as illustrated in
Figure 25 and inserted into the boss 32 with the molded plastic
material of the case having sufficient resiliency such that the
projections 190 and 192 slide up the grooves and into the recesses
19~ and l9~ as the slot 208 of the actuator slides over the handle
link pin at 88. Once the handle has been inserted in this manner,
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it is very difficult to remove and for all practical purp~ses,
is permanently attached to the upper portion 14 of the circuit
breaker case by rocking it back and forth between right and left
positions. ~he toggle mechanism may be manually actuated to
move between the contact open position of Figure 2 and the contact
closed position of Figure 4.
Figures 26 and 27 show the details of the lower molded case
section 16. ~his is illustrated in Figure 26 as having a central
protrusion 210 which has been omitted from the previously described
figures for the sake of clarity. ~t also shows projeCtiOnS 212
and 214 adapted to be received in corresponding slots in the
upper case section 14 and which projections correspond on the
other side of th~ lower case section 16 to the pxojections 22 and
24 previously described. Each one of the sides 216 and 218 is
provided with a corresponding set of three arc chute slots 220
in Figure 26 and 222 in Figure 25 adjacent the contact terminal
2D and remote from that portion o~ the case receiving the coil
terminal 18. ~agnetic metallic arc baffle el~ments are simply
slipped into the case through grooves 220 and 222 and are retained
in position by thé upper or outer case section 14 when molded
circuit br~aker case sections 14 and 16 are slipped together.
~igure 28 shows a modified case construction and this embodi~
ment i generally designated at 220. The upper case section 222,
comprises a pair of resilient mounting "wings" of the type shown
in assignee's U.S. Patent 3,749,873, preferably serrated at 228
and 230 t9 provide roughened outer surfaces which assist in
mounting it to an instrument panel along with the integral rim
232. This embodiment is charactexized principally by the fact
that it inc~rporates a rocker handle 234.
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1~3S'75~ '
Referring to Figure 29, the circuit breaker 220 has a
rocker handle which, as previously described, is received by
a pair of circular projections formed integral with the inside
of the breaker housing as indicated ~y dash lines at 236 and
23~ in Figure 30. These are received in cooperating circular
recesses in the handle 23~ and communicate with grooves on each
side such as the groove 240 in Figure 29. The handle structure
is essentially the same as in assignee's U.S. Patent 3,749,873.
At its lower end, it is provided with a slot 24~ which engages
and drives the pin 88 of the handle link 54. Beneath the - -
rocker handle 234 is a lamp 244 mounted on a lamp bracket or
holder generally indicated at 246. The lamp is connected by leads
248 and 250 to lower case center terminals 252 and 254 which
pass through suitable apertures in the lswer case central pro-
jèction 210. As best seen in Figure 30, the two sides of the .
frame 38 support the lamp bracket 246 on which, in turn, is
mounted the lamp 240. ~his is retained in the-hollow space
portion 256 in the underside of rocker handle 234.
Figure 31 is an enlarged view of the lamp brac~et 246,
Figure 32 is an end view of the lamp bracket and Figure 33 is
a top plan view of it. The bracket comprises a pair of bow
~haped ~upport arms 248 and 250 each with central slots, 252 and
254, by m2ans of which the bracket is secured to the pin 52.
These support arms are formed integral with a pair of cross ~ars
256 and 258 which, in turn, support an elongated, shallow substan-
tially U-~haped m~mber ~60 having a central recess curved in the
shape of a portion of a circle, as illustrated at 262 to conform
with and support the underside of the lamp 240. A member 260 is
provided with reenforcing ribs 264 and 266 and a pair of holes 268
and 270. In normal pxactice, the lamp just sits in the shallow
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3~i754 1~
semicircular groove 262 but, if desired, it may actually be
attached to as well as supported ~y the bracket through
the use of a small amount ~f epoxy adhesive.
Figures 34 and 35 illustrate how the rocker handle 234 is
inserted into the circuit breaker housing. The handle is first
inserted in a rightward and downward direction, as illustrated
by the arrow 272 in Figure 34 so that the circular projection _
238 slides into and along groove 240 and the corresponding pro-
jection on the other side of the outer case 22Z slides along its
L0 similar corresponding groove. In order to get the projection
into the corresponding rocker handle recesses, such as the
recess 274 in Figure 34, the rocker handle is then moved more
vertically downwardly and to the left as indicated by the arrow
276 in Figure 34, so that the projection 238 snaps past the lips
278 and 280 and groove, or slot, 246 slips over the handle linX
at 88 As before, this is done with the mechanism of the
circuit breaker set in the manually open contact position sf
Figure 2.
Figure 36 shows a further modi~ied embodiment qenerally
indicated at 282, in which like parts again bear like reference
numerals. This circuit breaker embodiment has an upper case 222
similar to the embodiment sh~wn in Figuxe 28 but is characterized
by a push button type handle 284. In this embodiment, the
cixcuit breaker operation is push to open, push to close and this
action is illustrated in Figures 37 and 38, the former illustrating
the circuit breaXer mechanism in the manually "on" position with
the contacts closed, while Figure 38 shows the "off" position or
manual contacts opPn position of Figure 2. Handle 284 is provided
with an actuator, a portion of which is illustrated at 28~ in
~igures 37 and 38 and ~h mechanism is provided with a modified
handle link 288 having a pair ~f semicircular grooves or
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ll~S7S0y
recesses 290 and 292- Wh~n the device is in the position
illustrated in Figure 37, downward pressure on the button 2~4
causes the actuator to enter gr~ove 290 rotating the handle
link 288 in a counterclockwise direction into the position
illustrated i.n Figure 38. A second depression of the button
284 when the device is in the position illustrated in Figure 38,
causes the actuator 286 to enter the recess 292, rotating the
handle link 288 in a clockwise direction about a pivot pin 52
back into the çlosed or on position of Figure 37. Successive
aepressions of the push button handle similarly cause the handle
link to rotate back and forth by alternate entr~nce of the
actuator 286 into the respective grooves 290 and 292.
Figure 39 is a front view to an enlarged scale with
portions in dash lines showing the push to open, push to close
handle 284 of Figures 37 and 38. ~igure 40 is a bottom plan
. view of the push button handle 284 and Figure 41 is a front ~iew
similar to Figure 39 with a portion in section showing the dis-
tortion of the actuator spring during operation.
Referring to Figures 39 and 40, the push button handle
284 $imilar to the rocker handle previously described, has a
hollow interior 294 which receives a lamp indicatea by dash lines
at 296 in Figure 39. This lamp is connected by electrical leads
298 and 300 to electrically conductive spring g~ide pins 302 and
304. Carried ~y the push ~utton,there is an actuator spring
:25 support 306 which carries an elongated coiled actuator spring
308. The spring is retained by the support at each end and is
free to deflect in the midale as indicated in Figure 41 It is
engaged by actuator blade 286 which comprises at its upper end,
a pivot 310 having ~ts ends xotatably reaeived in apertures
312 and 314 ~Figure 40) in the side walls 316 and 318 of the push
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< ~ 575~ ~ (
button. This pivot is connected by a centerpiece 319 to a
l~wer pin or actuator blade 320 which engages in the respective
grooves 290 and 292 of the handle link as illustrated in Figure 41.
Extending from the centerpiece 319 are a pair of wings 322 ana
324 whose upper edges or shoulders engage and deflect the center
portion of spring 30~ as the shoulder of wing 324 is shown doing
in Figure 41. It is understood that-when the actuator 286 pi~ots
; in the opposite direction with the actuator blade.or pin 329 re-
ceived in the slot 290, the shoulder of ~he ~ther wing, 322
similarly engages and deflects a corresponding central portion
of spring 308. Also forming a part of the handle 2g4 and formed
integral with it are the four ribs, 326J 328, 330 and 332, which
are involved in the joining of the handle to the circuit breaker
case as more fully describea below~
Figure 42 is a central cross section through the spring
support 306 of Figure 40, Figure 43 is a bottom plan view ~f the
spring support and Figure 43A is a cross.sec~ion.taken along line.
43A-43A of Figure 43. The spring support 306 is shown as having
a pair of proje~tio~s 334 and 336 at one end engaging one end wall
338 of the pushbutton in Figure 40 and a similar pair of projections
340 and 342 engaging the other end wall 344~ The cente~ of the
support 306 has a rectangular aperture at 346 to permit upward de-
flection of the center portion of the spring as illustrated in Figure
41. The ends of the spring are rPceived in semicircular cross
2~ section cutaways 348 and 350 communicating with the central aper-
ture 346. One cutaway 350, is shown in Figure 43A and it is under-
stood that the other cutaway 348 is ~ mirror image of cutaway 350
Figuré 44 is a front view and Figure 45 is a side view
of the actuator Z86. As can be seen in Figure 45, the top pivot
310 is, in fact, made of two separate pivot portions 352 and 354.
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Figure 46 is a central transverse cross sect;on through the
handle 284 and Figur~ 47 is a bottom plan-view of the handle by
itself cor~esponding to the plan view of Figure 40. The push-
~utton is preferabl~ made of a suitable plastic such as a clear
lexan type 141 and is preferably roughened or knurled on its
inside surface as indicated at 356 in Figures 46 and 47. ~ach
end of the handle is provided with a pair of recesses such as
the recesses 358 and 360 in the end 338 for receiving the cQr-
responding.projections 334 and 336 of the spring support illus-
trated in Figure 43. The other edge wall 344 is similarly pro-
vided with recesses 362 and 364 for receiving the projections
340 and 342 of the spring support 306 of Figure 43. These
recesses act to limit the upward movement of the spring support
relative to the interior of the push button. The end walls
also contain apertures 365 and 368 for receiving th~ spring pins
302 and 304 of Figure 39.
Figure 48 is a diagrammatic view showing the manner o~
originally inserting the button into the top of the case. ~he
case top is apertured as at 370 and the lower portion of the button
including the ribs, such as those illustrated at 328 a~d 332 in
Figure 48, are squeezea together as the button is pushed down-
wardly in the direction o the arrow 372 in Figure 48. The
plastic of the handle and the plastic of the case are both
sufficiently resilient that the button can be pushed in till
the tops of the ribs, such ~s those illustrated at 374 and 376
in Figure 48 snap outwardly underneath the ledges or inner rim
portions 378 and 380 of $he case to limit t~e outward ~ovement
of the handle and to prevent it from being removed once it has
been inserted into the upper section of the circuit breaker case.
~357~
Figure 49 is an exploded view illustrating the complete
acsembly of the pu5hbutton embodiment of the circu t breaker
case. The assembly is accomplished in two principal steps,
namely, the lower case section with the mechanism mounted on
it is first snapped into place through the lower end of outer
case section 222. Once this has been done with the mechanism
in the proper position, i.e., on the handle link positioned in
the manually contacts open location, the handle is then inserted
into the upper end of the outer case section 22~ with the
actuator mechanism of the handle properly engaging the handle
link. This sequence of assembly holds true for all embodiments.
In Figure 49, the push button handle 284 is properly aligned
by receipt of the ribs in corresponding grooves on the inside
surface of the case such as the grooves illustrated at 382 and
384. ~ectrical connec~ion to'the lamp in this embodiment is by
way of the handle spri~g 386 and 388 whose uppex ends receive the
spring guide pins 302 and 304. Springs 386 and 388 urge the
handle in the upward direction with the upper edges of the'
ribs engaging the upper end of the corresponding slots or
grooves such as those jus~'mentioned at 382 and 384. In addition,
'' the springs and pins provide an electrical circuit which is
completed by way of a pair of wire connectors 390 ana 392 which
engage the bottom ends o~ handle springs 386 and 388 tCoil com-
pression springs) and also electrically connecting to the leads
,
394 and 396 much in the manner of the rocker handle embodiment
previously described which ultimately lead to the lamp terminals
352 and 354~
It is apparent fram the above that the present invention
provides an improved snap action circuit breaker mechanism which
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may be very compactly constructed with a symmetrical arrang~-
ment and a variety of handle mechanisms utilizing the same
basic structure. This makes it possible for the circuit
breaker to be used in ~isible locations such as on an instru-
ment panel, much in the manner of a conventional switch. The
attractive and symmetrical appearance of the various circuit
breaker handles is consistent with modern instrument panel
design and the manual snap action makes it impossible ts
~tease" the circuit breaker and is consistent with the
on-off operation of most conventional switches. In this way,
the device of this invention provides the advantages of a
s~mple switch but adds to that , overcurrent protection in the
form of an overcurrent sensing coil and collapsible mechanism
By incorporating the delay tube construction and inertial delay,
nuisance tripping is, for all practical purposes, eliminated
and the device may be used as a switch and relied upon for i~s
operation in the manner of a conventional switch but with the
added feature of electrical circuit protection.
The invention may be embodied in other specific forms
without departing from the spirit or essential charact~ristics
thereof. The pxesent embodiments are therefore to be considered
in all respects as illustrative and not restrictive, the scope
of the invention being indicated by the appended claims rather
than by the oregoing description, and all changes which come
within the meaning and range of e~uivalency of the clai~s are
therefore intended to be embraced therein.
What is claimed and desired to be secured by United States
Letters Patent is:
