US1495849A - Electric switch - Google Patents

Description

C.' H. HODGKINS May 27 ELECTRIC SWITCH Filed Feb. 4'. 192] 8 M mar h kw a WITNESSES:

'ATTORNEY Patented May 27, 1924.

CHARLES H. H QDGKIN'S; PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE nnncrnrc & yams, e

Application filed February .4, 1921. Serial n. 442,370.

5T0 all it mm.-

Be it known that I, CHARLES H. Hoos- KINS, a subjectof the King of Great Britain,-

- and a resident of Pittsburgh, in the county vof Allegheny and State of Pemisylvania,

have invented a "new and useful Improvement in Electric Switches, of which the following is a specification.

My invention relates to electric switches 1 and particularly to those of the snap type;

' One of the objects of my invention s to provide a switchof the character describedwherein quickness and accuracy of movement are secured by the use of a number of parts.

- Another of theobjects of my invention is to provide aoswitch-actuating mechanism of such construction as'to insure against suspension of movement of the tensioned members when" the line dividing the opposite angles of-pressure reached, in order to lessen the tendency of the contact members to spark and tothereby conserve their life and efficiency. 4' 1 I accomplish the. foregoingiobjects' by means oftwo members pivoted eccentrically to each other, one of them having lost-motion engagement with/a movable contact;-

member and each supporting one of the ends of a tension spring in suchmanner'that, when the actuating member is'moved a distance sufiicient to carry't he spring across the centerline of one of the pivots, the direction of tension on the other -member; or striker arm, will; be shifted, and, by

the movable-contact member, it will strike the movable contact member a hammer blow during its movement to the reverse position, under the action of the spring, and will carry the movable contact member to open or to closed position, as the case maybe.

, My invention -is illustrated in the accom panying drawings as mounted in a switch box of any desired type.

1 Figural is a front elevational view of the "switch box, a portion of the cover being broken away to show the relation of the switch parts when in closed position;

' Fig. 2 is a similar view showing the parts in open position, and

Fig. 3 is a side elevational view of theparts in open position.

The switch is illustrated as mounted on r a base 3 thatv is supportedin a box 4 and 5 reason of its lost-motion connection with T mannrncrunms comrm, A CORPORATION or-r NNsYL- nnnornic swrroH. I v

includes a rocker arm 5 pi-voted-on'the base 3, at 6, a striker arm' 7, a movable contact .member 9 and a stationary contact member .the switch through engagement with the" one or the other of the projections 15 and 7. 16 of the rocker member 5. A' spring 17 is provided-for returnin the handle to. normal position after eac actuation ofthe. rocker mcmben'.

v When the parts 'are'in the position illus 7.-

trated in Fig. '1, the spring 13' exerts, a force tending to maintain the movable contact member 9 firm engagement with the stationary. member 12, by reason of the engagement of the lug 19 of the Striker arm' 8 r *7 with the arm 10 of the movable contactmember. If the handle 14 be now moved, in a counter-clockwise direction, into engagement with thelug 16 tocarry the spring =13 past the center line of the .pivot fi, the 8:

angle of tension exerted on the member 5 is shifted. and the movement of such memher is completed, independently'of the-handle'l l, and the spring passes the centenlline of the pivot 8 also, thusshifting theidirec- 9( tion of tension on-the striker. arm audQ-Icaus. ing it to snap, in a clockwise direction, to the position' in which 'it is illustrated in Fig.2.

7 During the travel of the striker arm to reverse position, its lug 20 will be brought into engagement with the arm 10 0f the movablecontact member, striking such arm a hammer blow and making a-quick break of the engagement between the contact menibers 9 and-.12 to open the'circuit through the terminals 21 and 22. stop members 25 and 26 are provided to limitfthe movement of the bar" 11 and the lever. arm 5.

An important feature off-the iuvention'resides in the provision ofmeans for overcoming the tendency in snap switches of the i ordinary type to are when the. spring ployed reaches the-dividing line of the opposite angles of pressure. At that point, there is ordinarily no pressure exerted on the movable contact member, and arcing takes place,

especially if the spring is at the neutral. point.

By means of my device, the movable contact member is constantly under the tension of the spring 13 until after the spring is carried past the center line of the pivot 6. When the spring has passed that point, the member is free to be moved by the spring. independently of the handle 14. The spring, by reason of its tension, moves .past the center line of the pivot 8 and snaps tionary contact member 12 and a stud 27v serve as stop members when the movable parts ar'efin the positionshown in Fig. 1.

If desired, the bar 11 may be dispensed with and the pivot 8 supported at a fixed point. and the arm be eitherpivotally supported or it may be merely flexible, without any substantial variation in the method of operation.

It will be apparent that the invention might be applied to a variety of switches. For instance, it could be as conveniently emin connection with multi-pole switches wherein the movable contact memher. at each actuation thereof, would close a circuit through any one of a plurality of stationary contact devices. as desired.

Various other modifications will he readily apparent to those familiar with the art. and the scope of my invention is limited only as defined in the claims appended hereto.

I I claim as my invention 1. An electric switch comprising, in combination. a movable contact member, a pivoted striker arm having lost-motion connec:

. tion with the movable contact member. a

vbination, a

messes a rocker arm pivoted eccentrically of the striker arm, a yielding member secured, at its opposite ends, to the rocker arm and the striker arm, respectively, and a lost motion means for moving the rocker arm to change the direction of force exerted by the yielding member upon the striker arm and thereby cause an actuation of the movable contact member, such actuation including a blow due to the said lost-motion connection.

3. An electric switch comprising. 'in commovable contact member. a striker arm having a lost-niotion connection with the movable contact member, said lostmotion connection being adapted to be taken up before movement is imparted to the movable contact member, a tensioning device normally i'naintaining the striker arm in one of its extreme positions. and a member having .lost motion connection with the striker arm for shifting the direction of tension exerted thereon to cause a snap movement thereof to reverse position. 7

4. An electric switch comprising, in combination. a movable contact. member. a pivoted striker arm having a lost-motion connection with the. movable contact. member. a

rocker arm pivoted cccentricallyot' the striker arm, a yielding member secured to the rocker arm and the striker arm, respectively, a handle for moving the rocker arm to shift the direction of force exerted on the striker arm by the yielding member, and a lost-motion connection between the handle and the rocker arm whereby the rockerv arm is free to snap to its opposite position when the spring has been moved past the center line of the points of pivotal support. 5. An electric switch comprising, in combination, a movable contact member. a striker arm having a lost-motion connection with the movable contact member. a tension member for normally holding. the. striker arm in one of its extreme positions, and a member having lost motion connection with i the striker arm for shifting the tensioning device to cause the striker arm to move to its opposite position.

6. An electric switch comprising. in combination. a movable contact member, a pivoted striker arm having a lost-motion connection with the movable contact member, a pivoted arm, and a tensioning device having one of its ends connected to the striker arm and its other end connected to the said pivoted arm in such position that. upon movementof the pivoted arm. the line of force exerted by the tensioning device crosses the point of pivotal support for such arm before said line of force crosses the point of pivotal support of the striker arm pivot.

7. The combination, in an'electrio switch, of a movable contact member, a pivoted striker member therefor, a, pivoted arm, a tensional connection between the arm and the striker member, and means whereby,

upon movement of the said arm, the line of tensional force is carried across the point of pivotal support for the arm before it is carried past the pivot of the-striker member.

' 8. The combination, in an electric switch, of a movable contact member, a striker member, a movable armya tensioning device normally exerting tension on the striker member and the arm to maintain them in one of their extreme positions, means for shifting the direction of force exerted on the arm and the actuating member, and means whereby the line of force during such change of direction passes the point of sup port of the movable arm in advance of its passage across the supporting point of the striker member.

9. In combination, in an electric switch, a

- stationary contact member, a. movable contact member, an operating lever, a tensional connection between the movable contact member and the operating lever for normally maintaining them in their extreme positions of movement, and means for maintaining the movable contact member in tensional engagement with the stationary contact member when the operating lever is free from the normal influence of the tension member.

10. In combination, in an electric switch,

- 'a mov'able contact memberfan operating lever, a tensional member adapted to normally yieldingly maintain the said lever and the movable contact member in their extreme positions of movement, and means whereby the movable contact member 'is'mai-ntained under the normal influence of the tensional member during such timethat the operating lever is not undersaid normal influence. 11. A switch comprising, in combination, a movable contact member and an operating lever both mounted on a fixed pivot, a

striker arm pivoted on the movable contact member at a point removed vfrom the said fixed pivot, a lost-motion connection between the outer end of the striker arm and the movable contact member, and means for exerting tension between the operating lever and the striker arm, the parts being so po-- sitione'd that tension isdirected against the ivotal'support on the movable contact memher during the time that the striker arm is moving from one point of lost-motion engagement to its other point of lost-motion engagement. I

12. An electric switch comprising, in combination, a pivotally supported contact-member, an operating lever for said member, a striker arm, means for exerting tension between the operating lever and the movable c0 contact member, and means whereby,-during movement of the operating lever in one direction, the movable contact member is maintained under efi'ective tension until the striker arm has been broughtinto operation 66 to impart movement to the movable contact member.

13. An electric switch comprising, incom blnation, a movable contact member, a 1 striker arm for imparting movement there- 70 to, and common means for actuating the striker arm and for malntaming effective tension on the movable contactmember during the time that the striker arm is being actuated.

- 14. A switch comprising a pair of relatively movable contact members and means for suddenly actuating'one of-said contact members into and out of engagement with.

the other'contact member and for biasing so said one contact member to its closed positionuntil the instant of actuation therefrom, said means comprising a spring and a member ivotally connected 'tosaid one'contact the other contact member and for biasing said one contact member to its closed position until the instant of actuation therefrom, said means comprising a spring, a plu vrality of movable supporting members therefor, one of'said supporting members having a pivotal connection and. a lost-motion connection to said contact member. 16. An electric switch comprising, in combination, a pivotally supported contact memher, an operating lever for said member, a ma striker arm, and means for exerting tension between the operating member and the mov able contact member and for causing the striker arm to im artmovement to the movable contact mem er in advance. of the pas sage of the li e of tensional force across the 1 point of piv tal support'for' the movable.

contact member. v

In testimony whereof, I have hereunto subscribed my name this 27th day of anul CHARLES HPHODGKINS.

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