US1252560A - Electric switch. - Google Patents

Description

C. T. EVANS.

ELECTRIC SWITCH.

APPLICATION FILED DEC. I5. |914.

1 ,252,560. Patented J an. 8, 1918.

1-4 M LA n UNITED sTATEs PATENT oEEIcE.

CLARENCF T. EVANS, OF MILWAUKEE, WISCONSIN, ASSIGNOR T0 THE CUTLER? HAMMER MFG. CO., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WIS- CONSIN. L

Specieation of Letters Patent.

ELECTRIC swITcn.

Patented Jan. 8, 1918.

@pacman mea December 1s. 1914. serial no. 877,342.

To all whomj z't may concern.'

"Be it known that I, CLARENCE T. EVANS, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Electric Swltches, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, formmg a part of this specification.

This invention relates to electrlc switches.

One of the objects of the invention is to provide a reliable and improved switch mechanism for making and breaking c1rcuit with a snap action. 1

A further object is to provide an eiicient and improved pressure operated switch of simple construction and positive operatlon.

Other objects 'and advantages will appear hereinafter in connection with a description of the accompanying drawing which. illustrates a typical embodiment of the invention, and in which, y

Fi ure 1 is 'a plan view ofy an electric switc.

Fig. 2 is a side view thereof, and

Fig. 3 is a sectional view on line 3-3 of Fi l.

For purposes of illustration the invention is shown as embodied in a double pole pressure operated switch comprising, in general, a pivoted operating lever 1 and an operated lever 2 pivbted thereto and movable thereby and having associated means to effect its accelerated pivotal movement for making and breaking circuit between movable contacts 3 and stationary contacts 4. A pressure device A is arranged to control move-l ment of the operating lever. j

Referring more specifically to the drawing the operating lever 1 is shown as an elongated. casting havin a depending lug 5 adjacent its free extremity to which lug the operated contact lever 2 is pivotally conl nected, as at G. Said contact lever extends in alinement with the operatin -lever and toward the pivotal axis of the atter. The movable contacts 3 are mounted at the ends of a transversely extending arm 7 which is journaled on a spindle 8 at the extremity of the operated lever 2 to have slight rotative play, for a purpose 'hereinafter set forth. A ifurcated link 9 straddles the lug 5 of the operating lever and is pivotally connected with the operated lever intermediate the contact end and the pivotal axis of the same as at 10. Said link extends beyond the axis of the lever 2 and is connected at its free extremity by a pair of coil springs l1, with fixed lugs 12 adjacent the pivotal axis ot the link. rlhe free extremities of the operating and operated levers project slightly beyond the point of connection of said levers and affords stops to limit the play of the link9 about its axis. The extremity of the contact lever 2 also functions with the end of the link for a further purpose, as will appear hereinafter.

The parts of the switch mechanism are supported by a frame which, as shown, comprises a base part 13 and a art 14 having complementary recessed portions forming a pressure chamber 15. A diaphragm 16 is disposed withinsaid pressure chamber and is clamped betweenrthe two parts of the frame by suitable securing screws 17. A piston 18 rests upon the pressure diaphragm and projects centrally through the cover portion of the pressure chamber, while a main spring 19, confined between an adjustable cap 20 and the end of the piston 18, biases the latter inwardly. The frame 14 has an elongated extension 20 to which is attached a rectangular insulating base 21 carrying the stationary contacts 4 and terminal binding posts. The operating lever 1 has-a bifurcated extremity straddling the piston 18 and pivoted between upstanding integral lugs 22 on the frame. The'bifurcations of the operating lever are also pivotally connected to the pressure piston by a pin 23 so that movement of said piston in response to varying pressures in the chamber 15 imparts a. pivotal movement to the switch operating arm. In practice, a pin 24 is alsoy preferably secured to the extension 2O of the frame and extends through an opening 25 in the switch operating lever. vAt the free end of said pin a secondary spring 26 is confined between an adjustable collar27 and a collar 28 adapted to rest upon a xed shoulder 29 of the pin.

tended to terminals 3l on the base 21,-Aihaving Vassociated binding posts.

In Fi 2 the swltch mechanism 1s shown in close position, the pressure 1n the chamvber 15 being below the pressure of the main spring 19. In. this position the contacts 3 on the operated lever are pressed into engagement with the stationary contacts 4 by the ener of the coil sprlngs 11 acting through t e medium of the link 9. Moreover, the plressure of the contacts at opposite ends of t e arm 7 is equalized dueto the rotative mounting of said arm, as above mentioned. Assuming now the ressure in the chamber 15 to increase to t e. amount predetermined for actuating the switch, the operating lever 1 is rocked outwardly and vcarries therewith the pivoted end of the contact lever 2. However, during a major portion of this movement, that is until the axis of the link 9 crosses the plane of tension of the springs 11 and until said link is thereby snapped, the coil springs 1l continue to exert pressure through the medium of the link on the inner end o the operated lever and maintain the movable cont-acts in engagement with the stationary contacts. rIhe operated lever 2 is thus moved about the contacts as an axis and the latter are accordingly preferably provided with rounded surfaces, as shown. Moreover, a slight bodily movement is imparted to the operated lever` which effects a sliding engagement of the movable and stationary contacts so that the faces thereof remain bright. As above indicated, when the axis of the link 9 crosses the plane of tension of the springs 11, the free end of the link is snapped pivotally and imparts a hammer blow to the free extremity of the operated lever 2. Thus the energy of said springs is suddenly directed toward moving the inner end of the contact lever outwardly toward the operating lever and circuit is thereby broken with a snap action. As the pressure a ain falls in the chamber 15 the operating ever is moved inwardly until the axis of the link 9again crosses the plane of tension of the springs 11 so that the free end of the link is snapped pivotally against the extremity of the operating lever and the energy of the springs is again directed to move the inner end of the operated lever to close circuit with a snap action. Itis to be noted that in opening circuit the operating lever 1 engages the collar 28 and compresses the secondary spring 26 before the contact lever is'actuated, while, in closing, said operating lever moves away from said collar 28 and 1s relieved from pressure ofthe spring 26 before the contact lever 2 is actuated. Therefore, by adjusting the normal compression of said spring 26, the predetermined naaaaeo pressure -limit for opening the switch may be varied without affecting the pressure limit at which the mechanism is desi edto close circuit. Ad'ustment of the mam spring 19, however, a ords means for varyin equally 7o the opening and closing pressure limits of the switch.

By offsetting the axes 10 and 6 'of the link and operated lever, as shown, it is apparent that during operation of the switch said axes are never in alinement with the extremities -of the springs 11. Accordingly the energy of said springs is always directed toward maintaining the contact lever in one of its extreme pcsitions and wavering thereof, with attendent arcing'between the contacts and slow movement in making and breakin circuit, is eliminated. It is to be note further, that the mechanism iscompactly arranged and com rises relatively few arts. Moreover, assemblyI of these parts is acilitated since the operating lever 1, the operated lever 2, the link 9 and the springs 1.1 constitute a single unit which may be separatly assembled and associated with the other parts of the device by mere ivotal connection of the operating lever to t e piston and attachment of the springs 11 to the lugs 12 on the elongated extremity of the supporting frame. It will be further observed that the arrangement and operation of the parts described effects a very wide' break when circuit is ruptured, since the axis 6 of the contact lever is moved widely before snap pivotal movement thereof about said axis.

lVhat I claim as new and desire to secure by Letters Patent is v 1. In an electric switch, in combination, a pivoted operating member, a wntact memer pivoted thereto for bodily movement therewith, a pivoted member carried by said contact mem er, and resilient means acting 'on said latter member whereby the same upon movement of said operating member in opposite directions effects a delayed snap movement of said contact member in correspending directions relatively toV said operating member. i

2. In an electric switch, in combination, a

ivoted operating member, a contact memerpivoted thereto for bodily movement therewith, said contact member being movable between two extreme positions, a pivoted member carried by said contact member and resilient means acting on said latter member whereby the same maintains said contact member in either extreme position during a major portion of the travel of said operating member and thereafter effects accelerated movement of the same relatively to said operating member.

3. In an electric switch, in combination, a

ivoted operating member, a contact memer pivotedv thereto for bodily movement 139.

tact member` relatively. member, said link initlatmgsnap move. ment of sald contact member 1n one direc- Y therewith, a. pivoted link carried by said contact member movablef between the same and said operating member and resilient means acting on said link whereby the same uon ,movement of said operating member e ects a delayed snap movement of said conto said operating tion by imparting a hammer like blow thereto.

4. In an electric switch, in combination, a pivoted operating member, a contact memer plvoted thereto for bodily movement therewith, said contact member being movable relatively to said operating member between two extreme positions, a pivoted link carried by said Contact member and having its movement limited in opposite directions by said contact member and said operating-- member, and resilient means connecting the free end of said link to a stationary part whereby said link maintains said contact member in either extreme position during a major portion of the travel of said operat- ,ingvmember and thereafter moves with a snap action to actuate said contact member relatively to said operating member. f

5. In an electric switch, in combination, a

ivoted operating member, a contact memer pivoted thereto for bodily movement therewith, said contact member being movable relatively to said operatingmember between two extreme ositions, a link pivoted to said contact mem er and having its movement limited in opposite directions by said4 contact member and said operating member, a spring eonnectedto said link on one side of the axis thereof and to a fixed part on the opposite .side of the axis thereof whereby said link maintains said contact member in either extreme position during a major portion of the ytravel of said operating member and thereafter moves with a sna action to actuate said contact member re atively to said o eratin member.

f 6.v n an eectric switch, in combination,

an operating member, an operated member vpivotally connected thereto having associ-' ated contacts, a link pivotally connected to said latter member on one side of its axis a stationary part on the same side of said axis and resilient connecting. means between said part and said link on the other side of' the axis of said operated member.

7. In an electric switch, in combination, al

pivoted Contact member having a movable axis, a link pivoted to said member on one 1 side of its axis, a fixed part on the same side of the axis of said member, a coil spring stretched between said part and the free end of said link at a point on the other side of the axis of said contact member, the pivotal axis of said link being movable across the plane of tension of said spring to thereby iting the movement of the free end of said link, the pivotal axis of said link being movable across the plane of tension of said spring to thereby eiect snap pivotal movement of said link and snap pivotal movement of said member, and a pivotedoperating member for said contact member.

9. In an electric switch, in combination,

an operating member, a bodily movable operated member pivoted thereto, means including a link pivoted to said operated .member and a spring connecting said link with a'xed part for biasing said operated member in either extreme position, said link and spring extending across the pivotal axis of said operated member and they pivotal axis of said link being movable across -thc plane of tension of said spring.

10. In an electric switch, in combination, a pivoted operating lever,. a paralel Aoperated lever pivoted thereto for bodily movement therewith, said operated lever having a contact adjacent one end, a stationary contact to be engaged bg said rst mentioned contact and means iasing said operated lever to either of two extreme positions and eifecting snap movements thereof from one position to another.

11. In an electric switch,'in combination, a pivoted operating lever, an operated lever pivoted thereto in parallel relation therewith and bodily movable thereby, said operated lever having a contact adjacent one end, a stationary contact to be engaged by said first mentioned contact and means biasing said operated lever to either of two extreme positions and effecting snap movement thereof from either position to the other.

12. In an electric switch, in combination, a pivoted operatinglever, an operated lever pivoted thereto in parallel relation therewith and bodily movable thereby, said operoperated lever having a contact at one end,`

a link pivoted to said operated lever intermediate the contact end and the pivotal axis of the same, and a coil spring having a fixed end within the limits of travel of the 14. In a pressure operated switch, in come.

bination, a pivoted operating lever, an alined operated lever pivotally mounted thereon and bodily movable thereby, saidl operated lever having a contact at one end, a link pivoted to said operated lever intermediate the contact end and the pivotal axis of the same, and a coil vspring having a fixed end within the limits of travel of the pivotal axis of said link and having its other end connected to said link on the opposite side of the pivotal axis of said operated lever, the ends of said spring and the pivotal axis of said operated lever and said link being arranged out of alinement in all positions of said operating lever.

1 5. In a pressure operated switch, in combina'tion, a pivoted operating lever, an alined operated lever pivoted thereto and movable thereby, said latter lever having a contact at one end, means biasing said contact toward said operating lever in one position of the latter and away from the same in another position thereof, said means including a link pivotally connected to said operated lever intermediate the contact end and the axis of the same, said link extendin across the axis of said operated lever an `having limited play at its free end between member pivotally mounted thereon in parallel relation thereto for bodily movement thereby and means associated with said latter member for biasing the same in closed circuit position with a pressure increasing gradually and proportionately to therate of movement of said operating member during a partial travel thereof in one direction for biasing said operated member to open circuit position with a pressure diminishing. gradually and proportionately to the rate of movement of said operated member during a partial travel thereof in the opposite direction and for biasing said operated member to each opposite position with a pressure suddenly augmented proportional to the rate of movement of said operating member for said partial travel thereof in either direction.

In witness whereof, I have hereunto subscribed my name in the presence of two wit nesses.

L. A. "WATSON, i TEKLA Bas'r.

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