US2242769A - Switch - Google Patents

Description

y 1941- c. J. WERNER 2,242,769

SWITCH Filed Feb. 17, 1938 2 Sheets-Sheet l xi 5 6 15mm CALVIN J. Wanna:

' ATTORNEY May 20, 1941. c. J. WERNER SWITCH Filed Feb. 17, 1938 2 Sheets-Sheet 2 INVENTOR CALVIN J. Wane! BY MM, v 64 ATTORNEY.

Patented May 20, 1941 SWITCH Calvin J. Werner, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporatlon of Delaware Application February 17, 1938, Serial No. 190,888

Claims. (Cl. 200-113) This invention relates to circuit controllers for controlling a plurality of circuits by means of a single operating member.

More particularly the present invention relates to the type of circuit controller disclosed in my Patent No. 2,135,371, issued Nov. 1, 1938, which is a division of my Patent No. 2,095,579 issued October 12, 1937. The circuit controller of my application and patent comprises two toggle switches provided for rapid separation and closing of contacts. Each of the toggle switches comprises a contact arm carrying a contact point movable between spaced members, a biasing spring for urging the contact arm toward one or the other of saidmembers and a movable toggle fulcrum which can be shifted relative to the action line of the spring to. change the bias of the spring. A movable member, common to both switches, carries the toggle fulcrums. This movable member is actuated by means including a temperature responsive element. The circuit controller provides for addusting the stop member in order that the spring bias of one spring is difl'erent from the spring bias of the other spring. In this way the two toggle switches are operated in a predetermined sequence.

The chief object of the present invention is to simplify the construction of the type of switch disclosed in my Patent No. 2,135,371 and thereby to reduce its cost of manufacture. The simplification of construction includes a simplification of the adjustment of the switch so that only one addustment is required for both toggle switches.

Further objects and advantages of the present invention will beapparent from the following description, reference being, had to the accompanyingdrawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is-a plan view of a switch embodying the present invention.

Fig. 2 is a side view thereof viewed in the di- 7 rection of the arrow 2 of Fig. 1.

ing other positions of the switch arms and stop members. 1

Figs. 8 and 9 are views of. the switch similar to Fig. 1 showing other positions of operation.

Fig. 10 is a perspective view of a leaf spring member which provides a contact arm and a contact biasing spring.

Referring now to Figs. 1, 2, 3 and 4, 20 desig nates a nonconducting base to which is riveted a Fig. 4 is a fragmentary sectional view on the 4 stationary metal frame 2| provided with a stiffening rib 22 which extends along the upper side of the frame 2| as viewed in Fig. 1, around the left hand end and entirely along the lower side. This rib 22 terminates in an ear 23 which is provided with a nonthreaded square hole for receiving a screw 24 having flats 25 which cooperate with the rectangular sides of the opening in the lug 23 to prevent turning of the screws 24 relative to said lug. The screw 24 receives a nut 26, the turning of which adjusts the screw 24 longitudinally relative to the hole in the lug 23. The frame 22 carries a pivot stud 30 which pivotally supports a movable frame 3| having an opening 32 larger at its right hand end than at its left hand end. The opening 32 at the right hand end is large enough to receive the head of stud 30 and the left hand end portion of the opening 32 is smaller than the head of the stud 30 so that that portion of the frame 3| which defines the left hand end of the opening 32 is received by that portion 33 of the stud 30 of smaller diameter than the head of stud 30. The frame 3| is retained in the groove 33 by the action of the means which moves the plate 3|.

The means for moving the plate 3| comprises two elements. One of these elements is the helical coil spring 34 anchored to a. spring eye 35 provided by the frame 3| and anchored to a nonconducting clip 36 which is supported by lug 31 extending from the flange 22 of the frame 2|.

The other means for moving the'plate 3| is a'wire 4|! secured at its left hand end to a lug 4| provided by the frame 3| and! at its right hand end to the screw 24. By turning the nut 26, the wire 40 can be placedunder tension which is opposed to the force exerted by the spring 34. The screw 24 is adjusted so that the wire 40 and the spring 34 will hold the frame 3| in a predetermined normal position as shown in Fig. 1. The length of the wire 40 is substantially equal to the distance measured" horizontally between the pivot stud 30 and the ear 23 to which the wire 40 is anchored. The material of the wire 40 has substantially the same coeflicient of expansion as the material of .the frame 2|. Therefore, the relation between the wire it and the frame 2t does not vary appreciably with changes in temperature of the sur rounding atmosphere. The wire fill is a thermal element responsive to variations in temperature due to the heating effects of an electric current passing through it. The circuit in which the wire 46 is located includes the frame it which is provided with a tapped hole 6 2 to which an electrical conductor may be secured. lihe pivot stud 36 carried by the frame 2i is insulated from the frame. To efifect this insulation the stud 3th is press-fitted into a non-conducting bushing d8 which is in turn press-fitted into a metal bushing 44 which is directly attached to the frame 36 as shown in the fragmentary sectional portion of 1 Fig. 2. Thus, the movable support 3% provides a portion of the circuit of the wire $6; This circuit continues through one of two toggle switches ac tuated by the plate iii and of which plate 3t is a common part.

The two toggle switches actuated by plate 3i will now be described. These switchesinclude similar leaf spring members designated in their entirety by numeral 56 and shown in perspective in Fig, 10. Each member 56 includes spaced spring arm portions which are in effect resilient contact arms. The arms 5? merge at the left end of the part with a hub or anchor portion 52 having a rectangular opening 53. The arms 5! merge at the right hand end of the part 50 with a pad or contact supporting portion 54 having an opening 55 through which the shank of the contact rivet passes. The pad 54 is provided with rectangular opening 56 which receives a contact stop member to be described later. Extending from the contact pad 54 and into the space between the contact arm portions 55, there is a portion 5i having s. notched end 58. The spring portion 5i constitutes a biasing spring for a. toggle switch. The notched end 58 of the spring 57 is received by a knife edge hearing or fulcrum as provided at the apex of a triangular notch 68 in the frame 3!. As shown in Fig. 3, the hub 52 of the two spring contact arms 5| is attached to the side edge of the frame 3! by providing the frame 32 with a lug 82 which is received by the rectangular opening 53 of the hub 52 and which is riveted over at 63. When the spring arm 5| is secured to the frame 3! in this manner, the spring portion 51 will be bowed as shown in Fig. 1 in order to urge the free end of the spring 5! in a clockwise direction. The spring pad 54 car ries a contact 64a which is urged against a stationary contact 65a secured to the insulating plate 20 to provide one of the switch terminals The circuit controller includes two toggle switches. The upper one as viewed in Fig. 1, has its parts indicated by certain numerals with the affix a and the lower switch has its parts referred to by numerals with the afiix b. I The construction of these toggle switches is identical. but the normal conditions of the two switches are different. The distance between the fulcrum a. and the contact arm 5 to is less than the distance between the fulcrum 60b and the contact arm Bib. Therefore, the action line of the bowed spring 51a makes with arm Bla an aculte'angle which is less than the acute angle between the action line of the bowed spring 51b and arm 5th. Therefore, thepomponent of force exerted by the spring 51a, which is effective to bias the contact Ma into engagement with the contact 6512, is less than the component of force of the spring 511; which is effective to bias the contact 6% into engagement with the contact b. This feature of construction is required for the purpose of eifecting the separation of contact parts 64a and 65a ahead of the separation of contact parts 6% and 85b.

The separation of the two pairs of switch contacts is effected by expansion of the wire 40 due to the heating effects of an electric current passing through it. As the wire 40 expands, the movable support 3i rotates clockwise by the spring 34 which tends to take up the slack. in the wire 40 as it expands. As the support 3| moves to the normal position as shown in 1 to the position shown in Fig. 8 the fulcrum 60a moves from the upper side of the contact 5m to the lower side. thereby causing the bias exerted by the bowed spring 570; upon the contact arm 5m to be reversed, whereupon the contact 64:: is shifted from engagement with the contact 65:: into engagementwith a stop screw it threaded through any suitable insulating collar in the car it integral with the frame it as shown in Fig. 8. The circuit of the wire it continues through the contacts 6% and 6522 which still remain in engagement as shown in Fig. 8. If further heating ,of the wire M takes place due to the application of an increased amount of electric current, the wire 46 will expand to permit further clockwise rotation of the frame 3! from the position shown in Fig. 8 to that shown in Fig. 9. During the movement of the frame 3| from the position shown in Fig. 8, the fulcrum 6% which previously has been located above the upper side of contact 5lb as shown in Figs. 1 and 8, will be moved to the lower side whereupon the bias of the bowed spring 51b will be reversed, thereby causing contact 64b to be separated from contact 6517.

As shown in Fig. 9, the movement of contact 84b away from contact 65b is limited by stop member which can best be described with reference to Figs. 5, 6 and 7 which shows the relation between the contact stop 80 and the contact pads 5G0. and 54b for three positions of the circuit controller, namely those positions shown in Figs. 1, Sand 9. The stop 80 is a metal stamping shaped so as to provide a. wider intermediate portion 8! and narrower end portions 82a and 82b which extend respectively. through the rectanguiar openings 56 of contact; pads 54a and 54b. The intermediate portion 8! is connected with the end portions 82a and 82b by shoulders 83:: and 83b which arespaced apart a predetermined amount, thereby limiting the distance to which the pad 54b of contact arm 5: can approach the pad 54a of contact 5la as shown in Fig. 7. The stop 80 therefore eliminates the need for a separate ear integral with the frame -2l 'to provide a stop' for the contact, 64b when it moves away from the contact 65b. Furthermore, the singl top screw I0 provides for adjustment he toggle switches. The position of screw, 10 etermines the amount of movement of the contact 64a away from the contact 650. Consequently, the amount of movement of contact 64b away from contact 65b is determined by the setting of the screw 10. The distance between shoulders 83a and 83b of stop 80 is such as to allow the contact spring arm 5!?) to move into the position shown in Fig. 9'in which position the distance between it and the fulcrum 60b is greater than the distance between fulcrum 60a and the contact spring arm Bla. Therefore, in Fig. 9, the bias exerted by spring 51b is greater than the bias exerted by SM. Therefore when the support 3i returns to normal position shown in Fig. 1, due to the decrease. in temperature in.

wire 40 which occurs atter the interruption of current flow through it, the bias exerted by spring 51a will be reversed before the bias exerted by spring 51b is reversed again. However, despite the fact that the bias of spring 51a is reversed again or restored to normal ahead of the re-reversal of bias of spring 51b, the contact a cannot move back into engagement with the contact 65a ahead of movement of contact 641) into engagement with the contact 65b. This is due to the fact that the stop member 80 will prevent return movement (downward movement as viewed in Fig. 7) of the spring pad 54a. ahead of downward movement of the spring pad 54b.

Therefore, the closing of the pairs of switch contacts takes place concurrently. Contact 540. may reengage contact 65a slightly ahead of the engagement of contact 54b with contact 65b, but this difference is so slight as to be negligible.

It is therefore apparent from the foregoing description of the construction and mode of operation of the present switch that the switch is of the same general type as the switch of my Patent No. 2,135,371 in that it comprises a support carrying two stationary contact stops, a plate pivoted upon the support at a point remote from the stationary contacts, contact arm members each carrying a contact engageable with a stationary contact, spring members each connected with a contact arm member near its contact, each contact arm member and its companion spring member being hingedly connected with the plate at spaced points, one being substantially nearer to the pivot than the other, and the action line of force of each spring member making a relatively small acute angle with the companion contact arm member and lying normally on the side of the arm member on which its companion stationary contact is located, the angle between one pair of arm and spring members being less than the angle between the other pair of arm and spring members, means for moving the plate, while the pairs of contacts remain in engagement, in a direction to shift the spring lines of action to the opposite sides of the arms in order to reverse the bias by the springs upon the arms whereby the movable contacts are moved away from said cooperating stationary contacts, the bias by the spring making the lesser acute angle with its contact arm being reversed ahead of the bias by the other spring, whereby one contact arm is moved ahead of the other, and other stops for limiting said movement of the contact arms away from the first mentioned contacts in order that restoration of the contact arms to normal position may be effected by reversal of movement of the plate.

The circuit controller of the present application differs from the switch of my application in that the contact controlling spring is a bowed leaf spring instead of being a helical coil spring and this contact biasing spring is integral with the contact itself which is of resilient material. This integral construction of contact arm and biasing spring results in simplicity and economy of manufacture.

In the switch of my Patent No. 2,135,371, there are two contact adjustments to be made. In the switch of the present application, there is but one contact adjustment. The relation between the switch arms is predetermined by the contact stop 80.

The switch of the present application may be connected in the circuit of a split phase A. C. motor in the manner shown in my Patent No.

2,095,579. The contacts a, it control the starting winding. When these contacts separate, the starting winding is disconnected, but the main winding remains connected through the contact 64b, 651). When these latter contacts open, the main winding is disconnected and the motor stops. Therefore, the switch functions to disconnect the starting winding after the engine has attained synchronous speed, and to interrupt the main winding circuit in order to protect the motor in case of overload.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An electric switch comprising a support carrying two stationary contact stops, a plate pivoted upon the support at a point remote from the stationary contact stops, contact arm members each carrying a contact engageable with a stationary contact stop, spring members each connected with a contact arm member near its contact, each contact arm member and its companion spring member being hingedly. connected with the plate at spaced points, one being substantially nearer to the pivot than the other, and the action line of force of each spring member making a relatively small acute angle with the companion contact arm member and lying normally on the side of the arm member on which its companion stationary contact stop is located, the angle between one pair of arm and spring members being less than the angle between the other pair of arm and spring members, means for moving the plate, while the pairs of contacts remain in engagement, in a direction to shift the spring lines of action to the opposite sides of the arms in order to reverse the bias by the springs upon the arms whereby the movable contacts are moved away from said contact stops, the bias by the spring making the lesser acute angle with its contact arm being reversed ahead of the bias by the other spring, whereby one contact arm is moved ahead of the other, a stop for limiting the movement of one of the contact arms away from its companion contact stop and a stop bar supported entirely by the two contact arms and having shoulders which limit the spacing of the contact arms when these arms are separated from their first mentioned contact stops.

2. An electric switch comprising a pivoted frame providing two fulcrums, two sets of relatively movable and stationary contacts, two resilient blade contact arms each carrying a stationary contact, each arm being secured to the pivoted frame; a biasing spring associated with each contact arm and hingedly engaging a i'ulcrum on the frame, the fulcrums normally being on the same side of their respective contact arms whereby both movable contacts will be biased toward contact closing position and whereby in response to movement of the common contact support, the bias of the two springs will be reversed in the same sense in order to separate the pairs of contacts, there being a single contact stop for engaging one of the movable contact arms to limit its separation movement from its companion stationary contact, and there being a stop bar supported entirely by the movable contact arms and having stop shoulders spaced apart so that separation of both pairs of contacts is limited through the stop bar by the engagement of one of the movable contact arms with the stop thermal means for actuating the frame in one direction and resilient means for operating the frame in the other direction.

3. An electric switch comprising a plurality of stationary contacts, a plurality of cooperating movable contacts each carried by a resilient arm provided with a biasing spring portion, a pivoted frame upon which said resilient means are secured, said frame also providing a fulcrum hingedly engaged by the biasing spring portion of each resilient arm, said fulcrums being so arranged relatively to each other that said arms are actuated simultaneously into contact engagement and sequentially'in the direction of contact breaking by their respective biasing spring portions in response to movement of said pivoted frame in one direction and the other respectively, thermal means for actuating said frame in the one direction; resilient means for actuating the frame in the other direction; a single stop engageable by the first moving arm from contact making position; a lost motion connection between the arms, providing a stop for the second arm moving from contact making position, said connection providing for the simultaneous movement of both arms into contact making position. 1

4. An electric switch comprising a plurality of stationary contacts, a plurality of cooperating movable contacts each carried by a resilient arm provided with a biasing spring portion, a pivoted frame upon which said resilient arms are secured, said frame also providing a fulcrum hingedly engaged by the biasing spring portion of each resilient arm, said fulcrums being so arranged relatively to each other that said arms are actuated simultaneously in one direction and sequentially in the other direction by their respective biasing spring portions in response to movement of said pivoted frame in one direction and the other respectively, thermal means for actuating said frame to eflfect sequential operations of the respective contact carrying arms;

resilient means for actuating the frame to effectsimultaneous operation of said arms; a single stop member for limiting the one arm in its movement in said other direction ahead of the other arm; and means supported between said arms,

limiting the movement of the second arm in said other direction and providing for concurrent movement of both arms in the said one direction.

5. An electric switch comprising in combination a movable frame; resilient means urging the frame in one direction; opposing thermal means adapted to actuate the frame in the opposite direction; stationary contacts; cooperating resilient contacts secured to the frame and provided with biasing means adapted to actuate the contacts in one direction as the frame reaches

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