US2668212A - Resettable switch - Google Patents

Description

1954 H. E. SCHLEICHER RESETTABLE SWITCH Filed Nov. 8, 1951 Wi i Patented Feb. 2, 1954 Sig-i161 toTh' Arrow-Hart & Hegenlali Electric Company, Hartford, Conn. a corporation of Gonnccticut Application November 8, 1951, S1'ittlN6. 255,364

11. Claims.

This invention relates to improvements in a manually operable circuit makingand breaking device'which is automatically operable for circuit interruption and is resettable manually. It' is an improvement upon my-P'atent 2,129,592; issued on Septemberli, 1938.

In that patent a single hairpin t'ype of compression spring was responsible for the snap action. Itwas a diflicult sort of spring to keep inservice over long periods under hard usage. The point oi engagement ofitsmoving end with the ac ztuating'. member was a troublesome point in the mecha'nism andthe spring had a tendency to wear there. Also the spring if overstressed for any reason or in continuous uselost its resillance,- it would provide a weakened and unsatisfactory spring action or might fail to operate.

Therefore an object of this invention is to provide" an improved spring arrangement which will overcome the difiiculties encountered with the prior spring arrangement and which can be ineorporated in the mechanism of my prior patent without substantial change therein so that old switches can readily be repaired and new switches can'be made using the old tools almost entirely.

Another object is to provide a differently functioning' switch arrangement while overcoming the aforesaid difficulties.

Other objects and advantages of: the invention willappear as it is described in connection with the accompanying drawing.

In the drawing I Fig. 1' is a sectional view showing in side elevation the interiorpart's of the circuit interrupting deviceembodying theinvention with the parts in closed circuit position;

Fig. 2 is a side elevation view of a circuit breaking device embodying the inve'ntion;

Fig. dis-a transversesectional view taken along line 33--of Fig. 1.

As in my Patent 2,129,592, the circuit making and breaking device is mounted upon a metal plate Ill. The mechanism is positioned between a pair of parallel plates-l2 and M which are secured to the base plate "land are secured together adjacent their top edges by a narrow plate- !6 parallel to thebase platel and provided with spaced apertures or slots within which slide the arms l8 and 20.

The device is operated byapairof push buttons 22 and 24 mounted uponthe'ends of the arms liland 20. respectively, the button 22 being pressed when it is desired to closethe circuit and the button 24 being pressed when it is desired either to: open thecircuit or to reset the device. The

2 lower or inner ends of these arms I8 and 20 are pivotally connected by'pins 25' and ZI'with opposite'en'ds of a link 26' which is pivoted at its'niidpoint upon a pivot 28. Also mounted upon the pivot 28 is the operating cam 36, one-half of which is substantially semi-circular while the other half tapers to a point.

For the purpose of operating the cam 30 asthe operating buttons are manipulated, a cam" operating member 32 having an irregular shape'is pivotally mounted upon the pivot pin 2l at'the One end of this cam" operating member 32 extends beyond the side" lower end of the arm 20';

edges of the parallel plates I2 and M; as indi' cated at 32!. The other end is divided by a central recess'into two parts, the upper part hav'- ing an inclined shoulder 3 23' for engagement by a pin st mounted upon the operating cam 3B; The lower part has a point 324' which normally will lie in the axis ofthe pin 28* upon which the cam in is mounted. In order to hold the pin 36 against the shoulder 323, duplicate coil tension springs 36 are provided each with one end hooked around the pin 3 and the other end hooked- These springs lie outside thearound the pin 2?. plates l2 and i l and engage ends of the pins 2! and which project through slots in said plates. on account of the action of these springs and the inclination of'the shoulder 323 the cam operating member tends to slip up or movein a clockwise direction (see Fig. 1). Such action is restrained by a latch-member 38* having an end portion stiengaged with the point 324 of the cam operating member when the device is set.

The latch 38 is pivotally mounted on a transverse pin 46 in the side plates l2 and I4. The end 38! of the latch member 38 is of hook shape, as illustrated, while the opposite end is of Y-shap'e'. The branch 3532 of the Y extends beyond the side edges of the parallel plates l2 and I l and has connected therewith one end of a coil tension spring :32 which urges the latch in'a clockwise direction. The other end of thecoil spring 42 is hooked over a lug it struck up out of the base plate it. The other branch 383' of theY extends toward the base plate Hi and is engaged with an arm l't l pressed'ou't from the center of a'latch tripping member 36 which is pivotally mounted upon a base plate 10'.

Automatic operation of the latch tripping member 56 is caused by a thermally responsive device 60 which moves a plate 63 clockwise and which in turn moves latch member 38 counterclockwise to disengage its upper end 3% from the point 32-ton the cam operating member. The

cam operating member is then free to move in a clockwise direction under the influence of the pressure of the pin 34 against the inclined shoulder 323. As soon as the pin 34 is disengaged from the shoulder 323, the pin may move into the recess of the cam operating member and the cam will thus be caused to pivot about the pin 28.

In order to reset the device after automatic operation, the reset button 24 must be depressed. This will cause the arm 20 and its pivot pin 21 and the cam operating member 32 to be simultaneously carried downwardly until the extension 32l engages the extension 382 of the latch. This engagement will cause a resetting of the parts.

A carrier 55 for the movable contacts is of U-shape with the legs 550i, 502 slidable over the outside faces of the plates l2 and [4. It carries an insulating block 5| and bridging contacts 53.

The carrier moves rectilinearly, guided by pins 53 and the projecting ends of pin 45 and also by a pin 54 extending transversely through the carrier legs and sliding in slots 555 in the side plates.

The motion of the cam 36 is translated into motion of the switch contacts by the following means.

Pivotally mounted on pin 54 between the side plates l0 and I2 is one end of a channel-shaped actuating member 52 for the contact carrier 50. The side plates 52 I, 522 of this channel member 52 lie between the planes of the cams 36. At the opposite end from the pin 54 a cam roller is mounted transversely in the actuators side plates 52!, 522. This roller engages the tapering surfaces of the cam point during the movement and in the various positions of the device.

To urge the roller 56 against the cam 35, duplicate coil tension springs 55 are located outside the plates l2 and I4. Their upper ends are looped over opposite outwardly-extending ends of the cam pin 34, and their lower ends looped over opposite ends of a transverse pin 53' which extends through the sides 52!, 522 of actuating member 52 below the roller 56. To permit lateral movement of the pin 51 as the actuator 52 moves, identical large openings 53 are formed in the frame plates l2, l4.

Circuit opening movement manually is caused by depressing the button 24 thereby causing the link 26 to rock clockwise. The downward movement of the pivot pin 21 will cause pivoting of the cam operating member 32 about its point 324 of engagement with the latch end 33!, carrying the shoulder 323 clockwise and allowing the springs 36 to pull the pin 34 and cam 30 in a clockwise direction. This causes the roller 56 to slide down the left inclined surface of the cam against the stress of the springs 55 until the roller 56 comes under the point of the cam, at which time the stress of the springs will cause the roller to slide up the right inclined surface of the cam 30, thus causing both the actuator 52 and the contact carrier 50 to move to the right with a snap motion into the open position in Fig. 2. The springs 36 thus provide means to indirectly transmit the motion of the manually operated link 26 to the operating cam 30 in circuit opening, in contrast to the direct positive transmission of the motion of the link to the cam by the cam operating member 32, during circuit closing.

In order to cause movement of the contacts to closed circuit position from off or the reset position, the circuit closing button 22 must be depressed thereby causing pivoting of the link 26 which will carry the cam operating member 32 upwardly together with the pivot pin 21 and the resetting arm 20. In moving to this position, the cam operating member 32 will pivot about its point of engagement with the latch 38. This movement will also (by reason of engagement of the shoulder 323 of the pin 324) cause counterclockwise movement of the cam 30. During this counter-clockwise movement, the roller 56 will move down the right-hand inclined face of the cam past the point 32 and will slide up the lefthand inclined face of the cam causing movement of the actuator 42 and the contact carrier 50 to the left.

It will be observed that the springs 55 which cause the snap action of the contact carrier are floatingly mounted in contrast to having one end anchored to a fixed support as heretofore. Thus in all the movements, both by manual and by automatic action, the springs 55 move bodily, their lower ends moving up and down with roller 56 and their upper ends moving sidewise with pin 34- Since pin 34 is mounted on the cam 30 and since the roller 56 acts directly on the cam 35, the entire force of the springs acts to cause movement of the cam past dead center. This is in contrast to prior devices wherein one end of the snapping spring or springs is anchored to a fixed part of the switch frame or base and the action of the spring is at only one point on the moving parts of the mechanism.

Moreover, in my new arrangement if one spring 55 breaks, the device will remain operative although the strength of its snap action will naturally be reduced.

It is obvious that my circuit interrupting mechanism is not limited to automatic operation by a thermal tripping device but may be operated as well by an electromagnet or other automatic tripping means.

Many variations within the scope of my invention will occur to those skilled in the art. Therefore I do not limit the invention to the specific form of the parts as illustrated and described.

I claim:

1. In a circuit controller, manually operable means, movable contact carrying means, operating mechanism including a floatingly mounted tension spring connected at one end to said movable contact carrying means for moving contact means to open and closed positions with a snap, means connected to the other end of said spring transmitting the motion of said manually operable means to said operating mechanism, means responsive to overload current acting upon said transmitting means to peroperation of said operating mechanism and to move the other end of said spring means independent of said manual means on overload.

2. In a circuit controller, a reciprocating contact carrier, operating cam means, manually movable means for operating said cam means, actuating means connecting said cam means and contact carrier, floatingly mounted spring means connected at one end to said cam means and at the other end to said actuating means, causing operation of said carrier with a snap motion, in combination with current responsive mechanism for causing operation of said cam means independent of said manually movable means.

3. A circuit controller as claimed in claim 2 having means pivotally mounting said cam means, the end of said spring means connected to said cam means moving from one side to the other of a line connecting the cam pivot and the point of connection of said spring means and actuating means during operation of said cam.

4. In a circuit controller, movable contact means, operating cam means, means including floatingly mounted spring -means between said contact means and operating cam means for causing said contact means to move with a snap in response to movement of said cam means, pivotally mounted manually operable means, means for transmitting the motion of said manually operable means to said cam means, said transmitting means including a member movable with said manually operable means and pivoting about the pivotal axis of said manually operable means during manual operation of the controller, said transmitting means also including spring means for causing said cam means to move in one direction in combination with current responsive mechanism for causing operation of said cam means by said spring means for automatic operation of the controller.

5. A circuit controller as claimed in claim 4 having means pivotally mounting said cam means, the end of said spring means which is connected to said cam means moving from one side to the other of a line connecting the cam pivot and the point of connection of said spring means and the contact-moving means during operation of said cam.

6. In a circuit controller, a movable contact carrier, operating cam means, actuating means for said carrier mounted on said carrier, floatingly mounted spring means connected at one end to said cam means and at the other end to said actuating means, resiliently engaging said cam means, manually operable means, means for transmitting the motion of said manually operable means to said cam means, said transmitting means including a member for positively moving said ca-m means in one direction and a resilient member for causing said cam means to move in the other direction as said manually operable means is moved in one direction or the other, in combination with current-responsive mechanism for causing operation of said cam means by said resilient member independent of said manually operable member.

7. In a circuit controller, movable contact means, actuating means mounted on said contact means, tension spring biasing means connected at one end to said actuating means and urging said contact means into one or another of two extreme positions, cam means for moving said actuating means, said spring means being connected at its other end to said cam means, manually operable means for operating said cam means, means transmitting the motion of said manually operable means to said cam means, said transmitting means including a rigid member for moving said cam means in one direction and a tension member for moving said cam means in the other direction, in combination with current responsive mechanism acting to free said rigid member and permit said tension member to automatically operate said controller.

8. In a circuit controller, manually operable means, movable contact means, operating mechanism for moving said contact means, spring means floatingly mounted between said movable contact means and said operating mechanism to cause contact movement with a snap, means transmitting the motion of said manually operable means to said operating mechanism, said transmitting means being constructed and arranged to provide for direct positive connection between said operating mechanism and said manually operable means when said manually operable means moves in one direction and a non-rigid positive continuously active connection between said operating mechanism and said manually operable means during the movement of said manually operable means in the other direction, means responsive to overload current acting upon said transmitting means to permit operation of said operating mechanism and to move the other end of said spring means independent of said manual means on overload.

9. In a circuit controller, movable contact means, actuating means moving with said contact means, spring means connected at one end to said actuating means and urging said contact means into one or another of two extreme positions, cam means for moving said actuating means, manually operable means for operating said cam means including a direct positive connection between said manually operable means and said cam means when said manually operable means moves in one direction and an indirect action whereas said manually operable means is operated in the other direction, said spring means being connected at its other end to said cam means, in combination with overload responsive means acting on connection to permit operation independent of said manual means on overload.

10. A circuit controller as claimed in claim 9 wherein the end of the spring means connected to said cam means moves over-center during the movement of said cam and actuating means.

11. In a circuit controller, manually movable link means, cam means movable in response to movements of said link means, cam operating means for transmitting movement of said link means to said cam means, latch means maintaining operative relation between said cam means and cam operating means, overload current responsive means for tripping said latch and permitting operation of said cam means independent of said link means in combination with movable contact means, resilient connecting means having one end connected to said cam means and the other end connected to said contact means for imparting movement to said con tact means as said cam means moves.

HAROLD E. SCHLEICI-IER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,129,592 Schleicher Sept. 6, 1938 2,150,012 Von Hoorn Mar. 7, 1939 2,320,437 Jennings June 1, 1943

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