US2487534A - Manual reset sequential trip switch mechanism - Google Patents

Description

Nov. 89 H949 J. A. 25,4@79534 MANUL RESET SEQUENTAL TRIP SWITCH MECHNISM Filed July s, w48

W Fi .2, 9 4 C@ a0 HQE.

Patented Nov. 8, 1949 MANUAL RESET SEQUENTIAL TRIP SWITCH MECHANISM John A. Favre, Drexel Hill, Pa., assignor to General Electric Company, ra corporation of New York Application July 8, 1948, Serial N0. 37,636

(Cl. 20D-116) Claims.

The invention relates to manual resetsequential'trip switch mechanisms, particularly of the type having thermal overload sequential tripping meansand a common .reset member controlling a pair of switches.

One kof the objects is to provide an improved mechanism of the above type for enabling a man- `ually operable trip-free thermal overload circuit ybreaker z-such, for example, as disclosed in my vPatent 2,435,432110 pre-trip a warning signal switch when a partial overload approaches the .switch separately or jointly with the second switch in case it alsohas beentripped.

:Another object is to provide a manually reset thermal overload circuit breaker with an improved form of warning signal switch mechanism that can be tripped before the circuit break- Aer is vtripped'and can be reset either by moving the circuit breaker manual reset member inthe `direction required to ,reset 'the circuit breaker or :by moving the manual operating member in the opposite direction when the circuit .breaker is closed.-

Another object is'toprovide for adjustably calibrating the amount of overload required to .pretrip the warning signal switch without varying "or interfering with the calibration of the overloadtripping value of the circuit breaker.

Further objects and advantages oi the invention will appear in the following description of the accompanying drawings showing a preferred form'of the invention and its scope is pointed out in the appended claims.

In the drawing Fig. 1 is a side view of a manual trip-'free thermal overload circuit breaker provided with -the improved pre-trip signalrswitch and having some V of the parts'broken away in order more clearly to show the details of construction. Fig. 2 is a partial top view and Fig. 3 is .an'end view of the switch'mechanism shown in Fig. 1. Fig. 4 is a partial side View of the switch mechanismshown in Fig. 1 indicatingl the relative positions of the rparts when Vthe signal switch is tripped .before the 'circuit breaker is .movable `circuit breaker contacts ftion in which the adjustable trip plate 30 formed in the molded base I3. :'springf3l has one end connected to the manual 2 tripped while Fig. 5 shows the relative position of the parts when the signal switch is separately reset with the circuit breaker still untripped. Figure 6 shows thesignal switch nal lamp.

As shown in Fig. l the circuit breaker manual reset and trip-free operating mechanism is of the same construction as described and claimed in my Patent 2,435,432. In this vconstruction a pair of IU are slidably carried in .alignment in a movable frame II formed of molded insulating material and having a pivot mounting pin I2 anchored in the molded base I3. The current is conducted to each contactl I0 by a separate iiexible connector I4. The cooperating stationary circuit breaker contacts I5 are secured to the base I3 by rivets I6 which also serve to mount in conducting relation therewith one end lof the thermalcurrent responsive connected to a sigrbimetal operating elements Il that carry the adjustable operating finger I8 at the free end thereof. Upon heating of the thermal element I1 by the current through thecontacts I0 I 5, the 1inger I8 is carried into operating engagement with the projection `I9 of the circuit breaker trip element 20 that is pivotally mounted on the molded base I3 by means of the pivot pin 2|. The spring 22 serves to bias the trip member 20 into posi- 23 engages with the latch 24 of the overcenter spring tripfree operating mechanism indicated generally by the reference character 25. This mechanism is provided with a manual operating member 28 of U -shape and having its two spaced-apart tapering legs 29 pivotally mounted in V-shaped pockets The overcenter operating member 28 as shown and the other end .connected tothe central pivot 32 of the toggle 33 having one end thereof connected to the molded circuit breaker contact carrying frame II by pin AV3II and the other end thereof connected to a collapsible lever 35 by means of the pin 36. The collapsible lever 35 is pivotally mounted on the base I3 by means of the pivot pin 38 and is held rigidly in place by means of the compound lever 'latch mechanism 40 that is maintained in a rigid condition when the latch latchplate 23.

Thusl as described more in detail in my prior patent, as long as the circuit breaker latch 24 is not tripped by operation of the thermal current responsive element I'I, the manual control member 28 Amay be'moved to the circuit closing positionvin which it is shown in Fig. l so as to carry 24 engages with the spring 3l over center to the left of pin 33 and thereby straighten toggle 33 to engage the movable circuit breaker contact I with the stationary contact I5. Likewise when manual control member 28 is moved to the circuit opening position, spring 3| is carried to the right-hand side of pin 35 and hence becomes effective to collapse the toggle 33 and thereby effect disengagement of the movable circuit breaker contact I from the stationary contact I5.

In case an overload current passes through the circuit breaker contacts III-I5 and heats the bimetal element I`I sufficiently to raise nger I8 and thus tilt trip member 2|! about pivot 2I to release the adjustable Calibrating plate 23 from the latch 24, then the collapsible latch mechanism 4D becomes effective to free the reset lever for movement under the bias of spring 3I about its pivot 38 to carry the toggle pivot 36 to the left of spring 3| and thereby permit the spring to collapse the toggle 33 and disengage the movable circuit breaker contact I0 from the stationary contact I5. When the bimetal element I1 has cooled suiciently to permit the trip member 2E! t0 return to its normal latching position as shown in Fig. 1, then the circuit breaker latch 24 may be reset by moving manual control member 28 to the right towards its circuit opening position. This will cause member 28 to engage with the upper end 35 of reset member 35 and thereby rep turn the reset member 35 to the position in which it is shown in Fig. 1 and at the same time operate the compound latch mechanism 43 to cause latch 24 to reengage with the calibration plate 23 of the trip member 20. Thereupon the overcenter spring 3I and toggle 33 again become eective to close the circuit breaker when the manual control member 28 is returned to the circuit closing position in which it is shown in Fig. 1.

In accordance with the present invention, the` pre-trip signal switch indicated generally by the reference character 45 is combined with the thermal overload circuit breaker mechanism so that the signal switch 45 is tripped by operation of the tripping member 2li when the overload approaches the value to which the circuit breaker is calibrated to trip and can be reset by operation of the manual control member 28 in opposite directions with the circuit breaker tripped and untripped. In the improved form shown the signal switch 45 is provided with a U-shaped frame 46 having the oppositely bent ends 46 of the legs thereof secured to the circuit breaker molded base I3 by means of hollow rivets 41 as shown more clearly in Figs. 2 and 3. The frame 45 carries a stationary contact member 48 suitably secured thereto by the terminal bolt 49 and insulated therefrom by the grommet 56 and strip 5E of suitable insulating material. The cooperating movable signal switch member or bar 5I is welded to and hence carried by a sliding actuating member 52 that extends through the elongated adjusting slot 53 formed in the top part of the.

frame 4S and also through a free running guide slot in the cross member 54 that extends between the legs of the frame 46. A biasing spring 55 is interconnected at an angle between the signal actuating member 52 and the cross member 54 so as to bias the lower end of the sliding member 52 into accurate latching engagement with the calibrating plate 23 of the circuit breaker trip member 20 to be released thereby before the circuit breaker latch 24 is released when the trip member 20 is moved by the thermal element I1. In order to adjust the value of partial overload required to trip the actuating member 52, the upper end thereof is arranged to slide in the rectangular notch 58' formed in an adjusting plate 59 that is adjustably secured to the top 46 of the frame 46 by means of the holding-down screw 60. Thus upon loosening screw ISI) and suitably adjusting plate 59, the lower end of the sliding actuating member 52 may be moved laterally more or less adjacent to the edge of the trip plate `23 so as to vary the amount of movement of the trip member 2B required to trip the signal actuating member 52 before the circuit breaker is tripped. Upon the resulting engagement of the movable signal switch member 5I with the stationary switch member 48 as shown in Fig. 4 a circuit to a signal lamp or other suitable warning device can be closed with the circuit extending through the frame 45 of the signal switch which may be grounded as shown in Fig. 6.

In order to reset the actuating member 52 into engagement with the adjustable trip calibration plate 33 of the circuit breaker trip member 20 with the circuit breaker both tripped and untripped, a reversably removable reset in the form of a double opposing cam member `B2 is provided and connected to be operated by movement of the manual control member 28 in opposite directions. The opposing cam member 62 is carried at the end of a connecting link 63 that slides in a slot 54 so as to engage either side of the cam member 62 with the contact bar 5I and thereby raise the bar 5I to reengage the lower end of the sliding actuating member 52 with the trip plate 23. The connecting link 63 is provided with an arcuate lost-motion slot 65 for receiving a pin 66 that is carried by the manual control member '28. This provides a lost-motion operating connection between the manual control member 28 and the opposing cam member 62 that can be taken up in either direction. The connecting link 63 also is provided with a bent ear 68 having an opening therein for receiving the hairpin loop end 69 of the tightly-coiled stiff spring IIl having the other end thereof secured to the cross member 54. Thus the link 63 in conjunction with the stiff spring 'I0 forms a resilient stop for engaging the pin 66 that is carried by the manual control member 28 against the left-hand end of the lostmoton slot -65 so as to limit the motion of the manual control member 28 to the circuit closing position in which it is shown in Fig. l. However, when the stiff spring 1I! of the resilient stop is flexed by movement of the manual control member 28 to the left to a position indicated by the dot-dash lines, then the connecting link 63 will since the lost motion is taken up move the opposing cam member E52 so as to engage the righthand side thereof with the movable contact bar 5I as indicated in Fig. 5 and thereby reset the sliding actuating member 52 into engagement with the trip plate 23 with the circuit breaker in the untripped position as shown in Fig. 1.

In case the circuit breaker latch 24 has been tripped after the signal actuating member 52 has tripped then the manual control member or handle 23 must be moved in the direction of the circuit opening position in which it is shown in Fig. 4 in order to reset the latch '24. When the latch 24 is released, and the breaker opens, the carrier 35 rotates counterclockwise a limited distance. The spring bias on the handle 28 is thus shifted causing the latter to move in a clockwise or opening direction until it strikes the projection 35 about midway and stops, thus indicating the breaker has tripped. To reset the the link 63 to carry the left-hand side of the opposing cam member `62 into engagement with the movable contact bar l and thereby raise the sliding actuating member 52 to reset the lower end thereof into engagement with the trip plate 23. yIn this way the warning signal switch is reset jointly with the resetting of the circuit breaker latch 24.

What I claim as Vnew and desire to secure by Letters Patent of the 'United States is:

r1. In a sequential trip switch mechanism, a movable trip member, means for moving said member, a pair of switches provided with separate latch `elements `biased into latching engagement with the trip member to be sequentially released thereby to trip one or both of said switches dependent upon the extent of movement of the trip member in one direction, and a reset member having connections including a reversely movable double cam for jointly vresetting said latching elements upon movement of the reset member Vin one direction .and .separately resetting the .latch element ofsaidLone-'switch upon movement of the reset member in the opposite direction.

2. In a sequential trip switch mechanism, a movable trip member, means for moving said member, a pair of switches provided with separate latch elements biased into latching engagement with the trip member to be sequentially released thereby to trip one or both of said switches dependent upon the extent of movement of the trip member in one direction, separate means for adjusting the extent of movement of said trip member requiredA to trip each of said latch elements, and a reset member having connections including a reversely movable double cam for jointly resetting said latching elements upon movement of the reset member in one direction and separately resetting the latch element of said one switch upon movement of the reset member in the opposite direction.

3. In a sequential trip switch mechanism, a movable trip member, thermal overload means for moving said member to a variable extent in one direction, a pair of switches provided with saparate latch elements biased into latching` engagement with the trip member to be sequentially released thereby to trip one or both of said switches dependent upon the extent of movement of the trip member in said one direction, and a manual reset member movable in opposite directions and having a lost motion connection for resetting the latch element of said one switch upon movement of the reset member in each direction and separate connections for resetting the latch element of the other of said switches upon movement of the reset member in one direction.

4. In a condition responsive sequential trip switch mechanism, a reversely movable trip member biased to move in one direction, condition responsive means for moving said member in the reverse direction upon corresponding variation of a condition, a pair of switches provided with separate latch elements biased into latching engagement with the trip member to be sequentially released thereby to trip one or both of said switches dependent upon the extent of movement of the trip member in the reverse direction, and

'a' manual reset member having a .lost 'motion connection including an opposing cam member 'for resettingthe latch element of said one switch upon movement of the reset member in each direction andseparate connections for resetting the latch element of the other of said lswitches upon movement 'of the reset member in one direction.

5. In a circuit breaker mechanism having a a thermal overload trip member and a reset member movable from the reset position to close :the breaker, a resilient stop limiting the movement of the reset member to the breaker closing position, a partial overload signal switch having a latch biased into latching engagement with said trip member to be pre-trippedthereby before the Ibreaker is tripped, and means for resetting said latch while the breaker is closed including a reset member having a lost-motion connection with said control member'taken up upon movement of -the control member lto ilex said stop.

6. In a circuit breaker mechanism having a .thermal overload trip member and a manual operating member movable between breaker opening and closing positions, a resilient stop limiting the movement .of the control member `to the breaker closing position, a partial overload signal switch having a latch biased into latching engagement with said trip member to be pre-tripped `thereby before the breaker is tripped, and means for resetting said latch while the breaker is closed or opened including a reversely movable reset member having a lost-motion connection with said operating member taken up both upon movement of the member to flex said stop and to the breaker opening position.

7. In a circuit breaker mechanism having a thermal overload trip member, a latch released thereby to trip the breaker, a manual operating member having breaker opening and closing positions and provided with means for resetting said latch in the breaker opening position, a resilient stop limiting the movement of the operating member to the breaker closing position, a partial overload signal switch having a latch biased into latching engagement with said trip member to be pre-tripped thereby before the circuit breaker latch is tripped, and means for resetting said signal switch latch while the breaker is closed or opened including a reversely movable opposing cam reset member having a lost-motion connection with said operating member taken up both upon movement of the member to` flex said stop and to the breaker opening position.

8. In a circuit breaker having a combined manual and automatic operating mechanism provided with a manual control member movable in one direction for opening and in the opposite direction for closing the breaker and with thermal overload means having a tripping member movable thereby to the circuit breaker tripping position, an auxiliary actuating member having means for biasing said member into engagement with the circuit breaker tripping member to be released thereby before the tripping member reaches the circuit breaker tripping position, a signal device operated by said biased actuating member upon release thereof, and lost motion reset connections extending between said actuating member and said manual control member for resetting the actuating member into engagement with the tripping member upon moveI ment of the manual control member in said one direction with the breaker open and in the opposite direction with the breaker closed.

9. n a circuit'breaker having an operating mechanism provided with a pivotally mounted control member manually movable in opposite directions for respectively opening and closing the breaker and thermal current responsive means having a circuit breaker pivoted tripping member movable thereby to the circuit breaker tripping position, a biased actuating member slidably mounted for engagement with the pivoted tripping member to be released thereby before said member reaches the circuit breaker tripping position, an auxiliary switch operated by said biased actuating member upon release thereof, a link having a lost motion connection with said pivotally mounted manual control member and an opposing cam member operated by said link for resetting the slidably mounted actuating member into engagement with the pivoted tripping member upon movement of the manual control pivoted member in opposite directions with the breaker respectively opened and closed.

10. In a sequential trip switch mechanism, a movable trip member having thermal current responsive operating means, a pair of switches provided with separate latch elements biased into latching engagement with the trip member to be sequentially released thereby to trip one or both of said switches dependent upon the extent of movement of the trip member in one direction, one of said switches having a trip-free overcenter spring operating mechanism provided with a manual-operating member reversely movable between two positions for opening and closing said one switch when the latch element thereof is in latching engagement with the trip member and provided with means for resetting said latch element upongmovement of said operating member to the circuit opening position thereof, a resilient stop limiting the movement of the manual operating member to the switch closing position, and said manual operating member having lost motion connections including an opposing cam member for resetting the latch element of the other of said switches upon movement of said operating member to the switch opening position thereof and separately resetting said latch element upon movement of said operating member to flex said resilient stop.

JOHN A. FAVRE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,169,586 Leonard Aug. 15, 1939 2,356,055 Hodnette et al Aug. 15, 1944

Images