US2230721A - Electric switch - Google Patents

Description

Feb. 4, 1941. I 1 KlMBALL 2,23@,721

ELECTRIC SWITCH Filed Feb. 9, 1957 2 Sheets-Sheet l Inventor: Donald G. Kim all,

His Attorney.

Feb. 4, 1941. AL 2,230,721

ELECTRIC SWITCH Filed Feb. 9, 1937 2 sheets sheet 2 Inventor:

Donald GJJKi ball, y W 6. .v His Attorney.

Patented Feb. 4; 1941 UNITED STATES PATENT OFFICE ELECTRIC SWITCH Donald G. Kimball, Stratford, Conn., assignor to General Electric Company, a corporation of New York Application February 9, 1937, Serial No. 124,855

17 Claims. (01. 200-6) My invention relates to electric switches and I9. Tracks 33 and 34 are each provided with more particularly to electric switches of the end notches 35 and 36 and a central notch 31. multi-position tumbler type. Located on the bottom of tracks 33 and 34 are An object of my invention is to provide an projections 38. For movement of the roller, 21

electric switch of the multi-position, tumbler from one of the notches to another, an operating type in which it is impossible to move the switch handle 39 is pro d and j u a led in the arms from one operative position to another without 20 and 2| by means of a pivot pin 40. Operatstopping the switch in an intermediate position. ing handle 39 is provided at its lower end with Another object of my invention is to provide cam surfaces 4| which engage 1er'21 adj cen an improved electric switch of simple construci-ts ends. When the switch is in its inoperative 10 tion which may be manufactured and assembled P s t as Shown in the roller 1 is 10- at a, relatively low cost, cated in the' central notches 31 of tracks 33 What I consider to be novel and my invention a d 3 and t e operating an e 9 s in a verwill be better understood by reference to the folical position. To en the movable contact lowing specification and appended claims when H W th the Stationary contact l2 the cam l1 considered in connection with th accompanying must be rotated in a counterclockwise direction drawings in which Fig. 1 is a perspective view whi h i mpli h y m ving t p r n of the assembled switch; Fig. '2 is a side sectional a d e 39 t t right o the Position indicated view; Fig. 3 is a side view of the operating mechin Fi 2. p n th m v me f e p r ti anism; Fi 4 is an exploded perspective view handle to t right, 101161 27 is moved down- 20 of the operating mechanism; Fig. 5 is a side Wardly in S s 5 a 26 Opp y e (1 view of the switch with a push button control; Spring 23 until it s ou Of engagement With e Fig. 6 is an exploded view in perspective f the notches 31. Further movement of the operating push bu tton assembly; Fig; 7 is ectional iew handle to the right permits the roller 21 under of a modified form of t h; i s is an the action of coil spring 28 to move to the left 25 ploded i w in perspective of th switch of i '7, into notches 35. To return the switch from the and Fig. 9 is a top view of the switch of Fig. '7. operative position in 2 o the in p r iv Referring to the drawings, Fig. 1, In indiposition in Fig. 1, the operating handle is moved at a b of insulating material t which is to the left. The initial movement of operating 0 secured a plurality of stationary contacts two handle a t indicated in y means of which r m t by 151 numerals n and of the cam surface 4| moves the roller 21 down- [2. For cooperation with the stationary con- Werdly in slots 25 a d 26 against t o p s ti tacts l l and I 2 two movable contacts l3 and of sprin 28 until the roller en ges e b tt m 14 are id carried by prings 5 and [5 4 of tracks 33 and 34. Further movement of oper- 35 respectively For moving the movabh t t ating handle 39 carries the roller 21 out of notch 35 I3 and I4 selectively into engagement with sta- 35 along t bottom of tracks 33 and 34 until ltionary contacts H and 2 cam n is rovjded further movement of the roller 21 is prevented Cam 1 is Secured to the end of haft as t by projections 38 in the bottom of tracks 33 and indicated in Fig. 4. Shaft la is journalled in p ratin h dle r l v r 39 must t be 40 supporting structure 19. Supportin tru t released and the roller moves into notch 31 under 40 I9 is of U-shape having two upstanding arm the action of coil spring 28. To move the switch 20 and 2L Between arms go and 2| a rocker to the operative position with movable contact 22 is provided and secured to shaft I8. Rocker in s ntw Stationary Contact the 22 is also f and has two arms 23 d cam 11 must be rotated in a clockwise direction 24 in the top of which are located elongated and the ope handle moved the left- 45 slots 25 and 26 in which a roller 21 is adapted s e p ra ha s. moved to the left the to be located. Roller 2-1 is held against the top roller 2'! is moved out of notches 3! and into of slots 25 and 26 by means of a coil spring notches 36. By the provision of projection 38 28 which is positioned by means of a retainer in the bottom of track 34 it is impossibleto move pin 29 provided with a tongue 30, slidably posithe switch from one operative position as from 50 tioned in a slot 3| of shaft {8. The top of the position indicated in Fig. 2 to the otherretainer pin 29 is sea-ted in an annular recess 32 operative position without releasing the operatin the center of roller 21. Roller 21 is adapted ing handle and permitting the switch to remain to ride in tracks 33 and 34 provided in the arms in the inoperative position for a sufficient period 1156 20 and 2! respectively of supporting structure of time to again move the operating handle to 1 failure of the motor.

the other operating position. The elapse of time necessitated by the release of the operating han-' die and 'the temporary positioning of the switch in the inoperative position is enough to insure that any are drawn upon the separation of the contacts will be extinguished before another set of cooperating contacts are engaged. It has been found that when a circuit is broken which is supplied by alternating current if the arc is extinguished at all, it will be extinguished within a few cycles of the alternating current voltage. In some switches it is possible to move the switch from one operative position to another within a period of time less than that necessary to extinguish the are drawn. When the switch in one position connects a conductor to one side of a three-wire 220 volt supply circuit and the other side of the conductor is connected to the neutral point the switching movement from one operative position to another may impress on the 110 volt are before it is extinguished a voltage of 220 volts. This frequently results in a disruptive are which seriously damages the switch, if not completely destroying it. Thus, by the provision of a stop assuring a sufficient lapse of time to permit the extinguishing of the arc drawn on the opening of an electric circuit the possibility of establishing a disruptive are by moving the switch directly from one operative position to another is prevented.

In Fig. 5, a modified form of switch is shown in which a push button control is substituted for the toggle operating handle of the switch of Fig. l. A U-shaped operating lever 32 is provided pivoted in the supporting structure it by means of a pivot pin 43. Operating lever 12 is provided with cam surfaces M corresponding to the cam surfaces Gil of operating handle 39. Push buttons 15 and at are loosely mounted on projections fill and 68 respectively of operating lever 42. To secure the assembly together a retainer it] is provided and secured in position by means of pivot pin #13 passing through openings 59 provided in the sides of retainer 49. The operation of the switch of Fig. 5 is identical to the operation of the switch illustrated in Fig. 1 except that the movement of the switch is initiated by pressure on either push button 45 or 46 depending upon whether it'is desired to move the cam I! in a counterclockwise or clockwise direction.

In Figs, '7, 8 and 9 a modified form of switch is illustrated which is adapted particularly for use as a motor reversing switch. In a motor reversing switch it' is particularly desirable to permit the motor to slow down before it is energized to cause it to rotate in the opposite direction. Ob-

viously, if the connections were changed instantaneously to reverse the motor before it had time to slow down at all, considerable strain would be placed on the conductors, bearings, and other parts of the motor. By utilizing a switch that insures a delay in changing the connections to re verse the direction of rotation of the motor, a reduction of strain on the motor is accomplished which may also prevent an early breakdown or In Figs. 7, 8 and 9, the operating mechanism is the same as the'operating mechanism illustrated in Figs. 3 and 4 and the same reference characters are used. in place of the cam Ill, as shown in Figs. 1, 2 and 5, for 7 operating the movable contacts, the movable contacts 50 and. 5E are secured directly to opposite ends of the shaft I8. Contacts 5E9 and 51] are insulated from shaft I B by means of discs 52 and 53 respectively which are provided with shoulders 54 and 55 on which the contacts are mounted;

For mounting the switch a supporting strap 56 isprovided with threaded openings 51 and. 58 adapted to receive screws for securing the switch in position. The stationary contacts 59 and 60 are mounted on two identical halves BI and 62 forming a housing of insulating material. The two halves 6i and 52 of the housing are secured together by means of integral ears 53 and 64 which extend into slots 85 and 5B of supporting strap 55 and integral ears til which extend from the bottoms of halves iii and 62 and enter openings lit in a bottom strap 69 which is secured to supporting structure 09 by means of screws iii. In the assembly of the switch the operating mechanism is first assembled with the supporting strap 56 surrounding the supporting structure is.

' ing discs 52 and are mounted on the ends of shaft 88. The stationary contacts 59 and all are mounted on the two halves 6i and The two halves are then placed in position around the operating mechanism (19 with the ears and 64 extending into slots and 56 in the supporting strap The movable contacts are prevented from sliding on of the ends of the shaft M3 by means of projections 70 and 772 of the two halves fill and as best indicated in Fig. 7. The two halves ti and 62 are then rigidly secured in position by meansof strap which is placed in position with the ears fill located in the slots To establish the circuit connections to cause the motor to rotate in one direction, the operating handle is moved to the left. If it is desired then to reverse the direction of rotation of the motor the operating handle is moved to the right. As explained in connection with Figs. 1 to 4, the

lit

Kill

to the right without first stopping in a vertical position. In this position the circuit connections are broken and so the motor begins .to slow up before the switch can be operated to establish the circuit connections for the reverse rotation. If it were desired to use this switch to establish connections for rotating the motor at different speeds any desired number of circuit connections could be accomplished simply by providing the desired number of notches in the track 34. Also, the direct changing of connections without a pause could be prevented by providing any number of projections 38 in the proper locations.

From the foregoing it may be 'seen that a switch operating mechanism is provided which may be used for a multi position switch with means for preventing movement from one position to another without a pause in an intermediate position. Also, the switch is provided with a minimum number of simple parts which may be manufactured and assembled with facility and at a relatively low cost.

What I claim as new and desire to secure by Letters Patent of-the United States, is:

1. An electric switch comprisinga stationary contact, a movable contact, a supporting structure, a shaft journalled in said supporting structure, means carried by said shaft for moving said movable contact into engagement with said stationary contact, a rocker connected to said shaft, a roller carried by said rocker and adapted to engage a track in said supporting structure, a lever pivoted in said supporting structure and engaging said roller, and a projection in said track adapted to stop the roller in one position before movement to another position.

2. An electric switch comprising stationary contacts, movable contacts, a. supporting structure, a. shaft journalled in said supporting structure, means carried by said shaft for selectively moving said movable contacts into engagement with said stationary contacts, a rocker connected to said shaft, a roller carried by said rocker and in engagement witha track in said supporting structure, a lever pivoted on said supporting structure and engaging said roller, and means to stop the movement of said roller along said track in one position.

3. An electric switch comprising stationary contacts, movable contacts, a supporting structure, a shaft journalled in said supporting structure, means carried by said shaft for selectively moving said movable contacts into engagement with said stationary contacts, a rocker connected to said shaft, a roller carried by said rocker in an elongated slot, a spring biasing said roller to the outer end of said slot, a track in said supporting structure having a plurality of notches and a projection, a lever pivoted in said supporting structure and having projections engaging said roller to move it along said track whereby the projection in said track prevents the movement of said roller from one notch to another without stopping in an intermediate notch.

4. An electric switch comprising stationary contacts, movable contacts, a supporting structure, a shaft journalled in said supporting structure, means carried by said shaft for moving said movable contacts selectively into engagement with said stationary contacts, a rocker connected to said shaft, a roller engaging said rocker and a lever pivoted on said supporting structure and adapted to move said roller along a track having a plurality of notches and a projection, whereby said rocker may be moved from one operative position to another and stopped in an intermediate position by the projection on said track.

5. An electric switch comprising a supporting structure, a shaft journalled in said supporting structure, movable contacts carried on said shaft, a rocker connected to said shaft, a notched track having a projection opposite one notch, a roller carried by said rocker and adapted to engage said track, a spring biasing said roller to one side of said track, a lever pivotally connected to said supporting structure and engaging said roller, a supporting strap engaging said supporting structure, a two-part housing of insulating material enclosing said switch and carrying stationary contacts positioned to be engaged by said movable contacts, and a bottom strap cooperating with said supporting strap to secure said twopart housing in position.

6. An electric switch comprising a two-part housing of insulating material, stationary contacts carried by said housing, movable contacts positioned to selectively engage said stationary contacts, an operating mechanism connected to said movable contacts and adapted to move said movable contacts from one operating position to another, a supporting strap connected to said operating mechanism, and a bottom strap connected to said operating mechanism, said supporting strap and said bottom strap having openings receiving integral ears from said housing to secure the two parts of said housing together.

7. An electric switch comprising a. U-shaped supporting structure, a shaft journalled-in said supporting structure, movable'contacts carried by said shaft, a, U-shaped rocker having elongated slots near the ends of the arms, notched tracks having a projection opposite one notch provided in the two arms of said supporting structure, a roller carried in elongated slots of said rocker and engaging the tracks in the supporting structure, a spring biasing said roller to the top of the slots in said rocker, a lever pivoted in the arms of the U-shaped supporting structure and having cam shaped surfaces engaging said roller whereby movement of said switch is stopped at the notch with the projection opposite it upon movement from either side of said notch.

8. An electric switch comprising a supporting structure, a, shaft journalled in said supporting structure, movable contacts carried by said shaft, a rocker connected to said shaft, a track provided in said supporting structure and having a plurality of notches on one side and a projection opposite one notch on the other side, a roller carried by said rocker and engaging said track, an operating handle pivotally secured to said supporting structure and having a cam shaped projection engaging said roller, said camshaped surface holding said roller against the side of the track opposite from said notch in movement from one position to another whereby said roller may not be moved past said'projection without stopping in the notch opposite from said projection.

9. An electric switch comprising a supporting structure, a shaft journalled in said supporting structure, movable contacts carried by said shaft, a rocker connected to said shaft, a track provided in said supporting structure, a roller carried by said rocker and engaging said track, a lever pivoted in said supporting structure and having cam shaped surfaces engaging said roller, push buttons loosely fitting side projections of said lever, a retainer secured to said supporting structure and surrounding said push buttons whereby pressure on one of said push buttons will move said roller along said track from one operative position to another.

10. In an electric switch, a switch element having a plurality of operative positions and an intermediate inoperative position, a plurality of fixed and movable contacts, means operated by said switch element for engaging a movable contact with a respective fixed contact when said element is moved to an operative position and for disengaging said contacts when said element is moved to said inoperative position, and means including a notched track to lock said switch element momentarily at said intermediate inoperative position to prevent said switch element from being moved from one of said operative positions to another without stopping at said intermediate position.

11. In an electric switch, fixed and movable contact means, a switch element having a pluality of postions of rest including an intermediate position, means interconnecting said switch element and said movable contact means for controlling a circuit through said contact means when said element is moved to any one of said positions of rest, and means independent of current flow in the switch and actuated in response to movement of said switch element positively to prevent said switch element from being moved from any one of said positions of rest to another without stopping at said intermediate position.

12. In an electric switch, fixed and movable switch contacts, means to move said movable contact into more than two positions of rest, handle means for operating the :switch and means actuated by movement of said handle including stationary and movable members cooperating to prevent said movable contact upon moving from any one position toward an adjacent position from moving through said adjacent position without remaining therein when said handle means is moved substantially in an eifort to move said movable contact through said adjacent position without stopping, the cooperation of said stationary and movable members being independent of current flow in the switch.

13. In an electric switch, fixed and movable switch contacts, means to move said movable contact into more than two positions of rest, handle means for operating the switch; and means, including cooperating members at least one of which is movable and engageable by a part of said movable contact moving means, efiective upon operation of the handle to halt said movable contact in a position of rest adjacent its starting position when said handle means is moved substantially in an efiort to move said movable contacts from any one position of rest through a position adjacent the starting position without stopping therein, the operation of said cooperating members being independent of current flow in the switch.

14. In an electric switch, fixed and movable switch contacts, means to move said movable contacts into more than two positions of rest, handle, means for operating the switch, and means including a member movable in response to movement of said handle means upon operation of the switch to halt said movable contact in the position of rest adjacent its starting position when said handle means is moved substantially in aneffort to move said movable contact from any one position of rest through a position adjacent the starting position without stopping therein.

15. In an electric switch, fixed and movable switch contacts, means to move said movable contact into more than two positions of rest, handle means for operating the switch, fixed stop means and means movable in response to movement of said handle means upon operation of the switch and cooperating with said stop means to halt said movable contact in the position of rest adjacent its starting position when said handle is moved in an effort to move said movable contact from any one of said positions of rest through said adjacent position without stopping.

16. In an electric switch, fixed and movable switch contacts, means to move said movable contact into more than two positions of rest, handle means for operating the switch, a projection, and means movable in response to actuation of said handle means upon operation of the switch and cooperating with said projection to halt said movable contact in a position of rest adjacent its starting position when said handle is moved in an efiort to move said movable contact from any one of said positions of rest through said adjacent position without stopping.

17. In an electric switch, fixed and movable contacts, means to move said movable contact into more than two positions of rest, handle means for operating the switch, and means normally permitting movement of a portion of said movable-contact-moving means in a predetermined path and responsive to movement of the handle to restrict said path and halt said movable contact in a position of rest adjacent its starting position upon movement from any one of said positions of rest.

DONALD G. KIMBALL.

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