US1158427A

US1158427A - Electric switch.

Info

Publication number: US1158427A
Application number: US86882814A
Authority: US
Inventors: Frederic Barr
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-10-27
Filing date: 1914-10-27
Publication date: 1915-11-02
Anticipated expiration: 1932-11-02

Description

F. BARRC ELECTRIC SWITCH. APPLICATION FILED OCT. 27. 1914.

Patented Nov. 2, 1915.

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IIFBEDJERIC 1B 1. m 11:

PAT lflll or new roan, n. Y.

morale swrron. I

To all whom it may concern:

Be it known that- I, FREDERIQ BARR, a citizen of the United, States of America, and residing at New York, .in the county of Kings and State of New York, have invented new and useful Improvements in Electric Switches, of which the following is a specification.

The objects of my invention are to provide in simple and practical form an electric switch of high current-carrying capacity and having a quick-make and quickbreak action.

The invention relates particularly to switches of the so-called pull fer lever type and one of the special objects of the invention is to provide a switch of this character in which it shall be impossible to retard action of the switch, as heretofore, by

objectsare attained by operating the movable member of the switch by a switchthrowing spring which is first shifted 1n 8. way to put it under the proper tension and is then, when tensioned, automatically cou pled in switch-throwing engagement with the movable switch member and further by automatically releasing the throwing spring from its tensioning means when said tensioned spring is thus engaged with the switch member.

Other features and details of construction will appear as the specification proceeds.

Figure 1, is avertical sectional view of a pull switch socket embodying the invention. F ig..2, is a side elevation of the same, with the screw shell removed. Fig. 3, is ahorizontal sectional view taken substantially on the plane of the line 33 in Fig. 1, and showing the switch parts as they appear when just operated and before the ull on the chain has been released. Fig. 4, 1s a drop perspective view of the parts which go to make up this form of the switch, with the exception of the upper member of the base. Fig. 5, is a detail sectional view illustrating one of the relatively stationary switch contacts and the Specification of Letters Patent.

arc-interrupting shoulder at the upper end thereof. Fig. 6, is a detail plan view of the anchorage for the spring which returns the spring-throwing lever. Fig. 7, is a plan view of the invention as adapted to a wall switch of the type disclosed in my patent #1,097,207. Fig. 8, is a plan view showing the invention embodied in a lever type switch. Fig. 9, is a view of a modification wherein the spring-tensioning lever is omitted and the pull chain is, attached directly to the switch lever.

Referring now to the drawing more in detail, 11 designates the switch base, constructed usually of porcelain or like insulating material and provided in this particular instance with a pair of upwardly inclined ratchet teeth 12, and with seats or recesses 13, alternating with such ratchet teeth. In the lamp socket type of switch shown in the first four views the switch base is made in two parts, the upper part 11, acting as a cover or protection for the switch mechanism, but the base may if desired, be made in one part, as is common in the art.

Seated in the recesses 13 are the relatively stationary switch contacts 14 and 15. These contacts are of novel construction in that they have a flat base or anchorage portion 16 from one end of which there rises an inclined spring contact-making portion 17, the upper end of which, when unrestrained, normally projects slightly above the planeof an arc-interrupting shoulder 18. This arc-interrupting shoulder, as indicated in the detail view, Fig. 5, is located closely adjacent the upper end of the inclined contact so as to form substantially a continuation of the same and it is shown as inclined to accord with the incline of the contact when such contact is pressed down into the plane of the Patented Nov. 2, 1915.

Application filed October 27, 19%. Serial No. 868,828.

which here takes the formof an insulating disk 20 journaled on the central upstanding spindle 21 and carrying on its underside the contact plate 22 which is provided with oppositely disposed downwardly, inclined spring contact arms 23, ridingon the stationary contacts and insulating ratchet teeth of the base. The switch plate is shown connected with its insulating carrier disk by providing it with-an-angular opening 24:

screwed onto the upper end of the spindle.

At its lower or free end the switch-throwing spring has a one-way driving connection with, the movable switch member in the direction of rotation of said switch member. This one-way drivi g connection is provided in the present nstance-by interposing a switch lever 32 between the throwing spring and the movable switch lever and providing this switch lever withpawls or teeth 33 engaging with shoulders provided by corresponding ratchet teeth 34 on top of the movable switch member. The switch lever is pivotally engaged on the splndle,

being for that purpose usually provided with a central sleeve portion loosely fitting the spindle, and its ratchet teeth face forwardly so as to have driv ng engagement with the movable switch member in the direction of its rotation. The throwing spring is shown connected with this ratchet'lever by hooking its lower end asat .37 to engage a lug 38 struck up from the lever. The

lever to rotate it and the movable switch member which it drives in the forward or circuit changing direction.

The ratchet teeth on the top of the movable switch member are usually provided as shown, by setting a plate 39 carrying the ratchet teeth into the top of the insulating carrier disk.

From the foregoing it will be evident that upon a retractive or backward movement of the switch lever theswitch-throwing spring will be tensioned but no movement will be imparted to the. movable switch member. When in this tensioning movement the switch lever moves back a distance equal to one ratchet tooth, the lever drops down into engagement with a fresh ratchet tooth on the switch member and the then-tensioned spring is thus coupled in switch-throwing engagement with the movable switch member.. Upon release of the switch lever the spring will then act to throw the switch member with a quick snap action. The forward throw of the switch lever is limited by a stop {10, carried in the first form illustrated, by the upper block of the base. a

In the switch-throwing action just de scribed, the contact arms 23 of the switch member are snapped either from the insulating ratchet teeth. onto the stationary switch contacts or from the stationary con tacts onto the insulating ratchet teeth and the circuit is thus snapped closed or snapped open, depending upon the original condition of the switch. Since the stationary spring contacts normally project slightly above the plane of the arc-interrupting shoulders 18 at the ends thereof (Fig. 5), the switch arms23 in riding off the insulating ratchet teeth, will have to engage said contacts before they can touch the arc-interrupting shoulders and it will be impossible moreover for such shoulders to hold the switch arms away from the contacts. The formation of any imperfect contacts is thus prevented at these points. This upstanding feature of the stationary spring contacts also causes them to brake or check the forward movement of the movable switch member and hence to prevent over-throwing of the switch. The spring contacts yield somewhat under the pressure of the movable switch member until they lie'substantially in the plane of the arc-interrupting insulating shoulders. When the switch is thrown into the circuit off position the switch arms 23 are snapped from engagement withthe spring contacts, up over the inclines of the arc-interrupting shoulders and drop from said shoulders down upon the foot of the insulating ratchet teeth. These shoulders thus act as insulating barriers interposed at the instant of breaking circuit to positively interrupt and cut ofi' any are that might other- 4 wise have a tendency to form. spring thus has a bearing against the switch To prevent delaying or retarding of the action of the switch-throwing spring, I have provided means for automatically taking the control out of the hands of the operator once the throwing spring has been properly tensioned. Such means here takesthe form of a lever 43 pivoted on the" spindle above the switch lever and having a one-way connection with the switch lever for imparting a spring-tensioning movement thereto. This connection may be in the form of one or a number of downwardly struck pawls 44 on the tensioning lever facing in a direction opposite that of the switch movement and arranged to engage shoulders provided by a corresponding number of seats 45 in the switch lever. Disengagement of this pawl and ratchet connection between the springtensioning lever and switch lever is automatically eifected when the spring-is tensioned by supporting the tensioning lever so that LWWAW? it cannot follow the switch lever when that lever drops down at the time of its engagement with a fresh ratchet tooth on the switch member. The tensioning lever is therefore here provided with a supporting extension 46 adapted to'ride-upon a trackway 47 on the switch base, substantially at the instant of the engagement of the switch lever with the new ratchet tooth on the movable switch member. This trackway may be inclined upwardly somewhat, as indicated, to impart a slight lifting movement to the tensloning lever and to therefore insure a positive disengagement of the switch lever from the tensioning lever. The trackway for supporting the tensioning lever may be integral with the base but- I prefer to employ for the purpose a spring metal strip indicated at 41 in Figs. 2 and 4 which extends up at a slight incline and is secured in place by a screw 42.

The spring-tensioning lever is preferably made with a hub portion48 pivotally engaging over the switch-throwing spring and the central body portion of the lever is usually domed or bossed up, as indicated at 49 to accommodate and cover the connection between the throwing spring and the switch the tensioning lever on the spindle without removing the outstanding anchorage lug, the lever is usually formed with a radial slot 50 large enough to pass over the lug. The tensioning lever is returned back into driving engagement with the switch lever by a spring 52 having its lower endhooked into the radial slot 50 in the tensioning lever and its upper end anchored to the spindle. This spring can be relatively light since its purpose is merely to swing the tensioning lever back into holding engagement with the switch lever and it is usually loosely coiled so as not to obstruct the lifting movement of the lever in riding up the incline of the trackway.

The anchorage for the returning spring 52 in the first form of the invention is of novel construction "in that it comprises a flanged bushing 53 fitting within the upper end of the spring so as to form a bearing therefor and slotted in one side at 54 so as to slip down over the anchorage lug 29. This bushing is usually placed on the spindle, over the nut 30, which may be round to fit within the bushing and it may be held in place by a nut 55 applied to the end of the spindle. The flange 58. of the bushing is provided with a notch or notches 56 to take the upper end of the returning spring. The anchorage lug 29 when engaged in the slot 54 will hold the bushing against turning when the spring is thus engaged therewith. In addition to the slot 54, the bushing is preferably formed with one or more notches 57 in the inner periphery of its flange 58 to form a seat or seats for the anchorage lug 29. This permits of the bushing being slipped onto the spindle down over the anchorage lug '29, then turned to give the re;'. turning spring 52 the requisite tension whereupon the bushing may be allowed to rise with one of" the seats 57 therein engaging with the' lug 29 as indicated in Fig. 6. The bushing is thus non-rotatably secured upon the spindle and the nut 55 is in this case unnecessary.

The socket. switch illustrated in the first five figures is shown as controlled by a pull chain 60, which, in these views is attached to the spring-tensioning lever. The method of attaching the chain to the lever is novel, the lever being provided with a dependent extension 61 at its forward edge, in back of which the end ball of the chain is engaged and the flat top portion of the lever having an opening 62 the size of the-end ball and a communicating slot 63 extending forward and downward into the extension 61. The chain is thus engaged with the lever by simply inserting the end ball in the top opening 62 and allowing it to drop down in back of the downward extension. When the levers are in their normal position of rest against the stop 40, the switch lever 32 overlies the end ball and so prevents the chain becoming ing back idly over the teeth on the switch member. At the end of a movement sufiicient to place the throwing spring under proper switch-throwing tension. the switch lever has traveled far enough back for its teeth to drop down into engagement with a new set of teeth on the switch member. At the time the switch lever, and hence the tensioned spring, is thus automatically coupled in fresh engagement with the switch member, the tensioning lever is supported by its trackway and so cannot follow the switch lever as that lever drops to engage the new ratchet teeth. The switch lever in coupling itself to the movable switch member, thus in effect drops from beneath the tensioning lever and this drop is sufiicient to uncouple the connection between the tensioning lever and switch lever. The switch lever being now freed from the tensioning lever and coupled to the movable switch member, is thrown suddenly by the throwing spring, thereby making 1% or breaking the circuit as the case may be,

' on the chain is released the returning spring -52 returns the tensioning lever back into holding engagement with the switch lever. The stop 40 for the switch lever maybe utilized here also to limit the return movement of the spring-tensioning lever. The active movement of the tensioning lever is limited by a stop 65, which may like the stop 40 also be carried by the upper-member of the switch base. When the trackway is a metal strip, the automatic uncoupling of the switch lever and tensioning lever is assisted by the spring force of the strip. This metal strip may be adjusted by bending to properly cooperate with the other switch parts.

The circuit through the first form of switch disclosed may be traced as follows: from circuit terminal 67 down through the screw 68,- which assists in holding the two parts of thebase together, to the plate'69 which overlies the stationary switch contact 14, across the movable switch contact plate 22 to the other stationary contact 15 which is connected by screw 70 with center lamp contact 71. The other side of the line is from circuit terminal 72 down through screw 73, which also helps hold the two parts of the base together, to the plate 74 beneath the flange 75 of the screw shell contact 76. It will be noted that the contact 14 is held in place by a screw 77passed up through the base into engagement with the plate 69 overlying said contact. The screw 70 holding the other contact 15, engages in a nut 78 overlying the said contact.

The form of the invention illustrated in Fig. 7 is substantially like that described, the only material distinction being that the switch base '80, is in this instance, made angular in shape to fit within the boX or casing of a wall switch of the type shown in my Patent #1,097,207. In this form also the switch-throwing spring 27 and the returning spring52 are bothengaged with a single anchorage lug 81 on the spindle. One of the relatively stationary switch contacts appears at 82 in directengagement with an overlying circuit terminal 83 and the other switch contact is similarly engaged with the other circuit terminal 84.

In Fig. 8 the invention is shown applied to a lever type of switch of my own invention, .the control being had in this instance by means of a lever instead of a pull chain. The spring-tensioning lever 90 is accordingly provided with a handle extension 91 which projects out through the side of the casing (not shown) of the switch and by means. of which the said lever may be shifted tension the spring. The circuit terminals are designated 92 and 93 and these are directly connected with the relatively stationary switch contacts, the same as in the form shown inFig. 7 The switch-throwing and returning springs are in this instance also both engaged with a single anchorage, a notched nut 94, on the spindle. In other respects this switch is similar to the one first described.

Fig. 9 illustrates a way, in which the switch may be controlled directly by the switch lever and without using a springtensioning lever. In this case the pull chain 99 is attached directly to the switch lever 100. This switch lever is acted upon by the switch-throwing spring and has the oneway driving connection with the movable swltch member, as previously described. Consequently a pull on the chain tensions the spring and causes the spring, when tensioned, to be automatically coupled to the movable switch member and the release of the chain permits the spring to snap the movable switch member into the next position for a quick make or break as the case may be.

, My invention provides a switch of but few and simple parts having a quick-make and quick-break action and therefore capable of carrying a considerable current load. The arc-interrupting construction at the switch contacts in addition to preventing the formation' of arcs, prevents heating and burning of the contact parts. The control may be had by means of a' pull chain, a lever, or other form of handle as will be apparent to those skilled in the art and it will be understood that other modifications such as come within the scope of the invention may be resorted to. It will be further understood that the terms employed herein are terms of description rather than of limitation, except so far as may be required by the prior art.

What I claim is 1. In an electric switch, the combination of a movable switch member, a switchthrowing spring free of said switch member during tensioning movement of the spring, means for tensioning said switchthrowing spring and means for automatically coupling said spring, when tensioned, in switch-throwing engagement with the movable switch member.

2. In an electric switch, the combination of a movable switch member, a switch throwing spring free of said switch member during tensioning movement of the spring, means for tensioning said switchthrowing spring, means for automatically coupling said spring, when tensioned, in switch-throwing engagement with the movable switch member and means for auto- 'matically releasing the tensioned spring manta? 3. In an electric switch, a movable switch member, a switch-throwing spring fast at one end and having its opposite end free for a tensioning movement, means for imparting a tensioning movement to the free end of the spring and means for automatically coupling the spring at the end of its tensioning movement in driving engagement with the switch member.

4. In an electric switch, a movable switch member, a switch-throwing spring fast at one end and having its opposite end free for a tensioning movement, means for imparting a tensioning movement to the free end of the spring, means for automatically coupling the spring at the end of its ten- I sioning movement in driving engagement with the switch member andmeans for automatically releasing the spring when coupled with the switch member from the tensioning means aforesaid.

5. In an electric switch, a switch member rotatable in one direction, a switch-throwing spring capable of movement in the opposite direction for tensioning the same, means for imparting a tensioning movement to said spring and means for automatically coupling the spring when in tensioned position in switch-throwing engagement with the rotatable switch member.

6. In an electric switch, a switch member rotatable in one direction, a switch-throwing spring capable of movement in the op: posite direction for tensioning the same, means for imparting a tensioning movement to said spring, means for automatically coupling the spring when in tensioned position in switch-throwing engagement with the rotatable switch member and means for automatically disconnecting the switchthrowing spring from the tensioning means at the end of the tensioning movement,

thereof.-

7. In an electric switch, a movable switch member, a switch-throwing spring, means for tensioning said spring, means for automatically coupling said spring, when tensioned, in switch-throwing engagement with the movable switch member, means for automatically disconnecting. the tensioned spring from the tensioning means and means for automatically reengaging the tensioning means with the spring in readiness for the succeeding switch operation.

8. In an electric switch, a switch member rotatable in one direction, a switch-throwing spring exerting tension to propel the switch member in the direction of its rotation and a switch lever interposed between its rotation and the throwing spring engaging the said lever to propel it in the direction of the switch movement.

9. In an electric switch, a switch member rotatable in one direction, an oscillating switch lever having a driving connection with the switch member in the direction of its rotation and movable independently of the switch member in the reverse direction, a switch-throwing spring bearing against the switch lever in the direction of rotation of the switch member and a movable springtensioning member having a driving connection with the switch lever in the reverse direction aforesaid whereby the switchthrowing spring will be tensioned by the movement of said tensioning. member in a direction. reverse to the movement of the switch member.

10. In an electric switch, a switch member rotatable in one direction, an oscillating switch lever having a driving connection with the switch member in the direction of its rotation and movable independently of the switch member in the reverse direction, a switch-throwing spring bearing against the switch lever in the direction of. rotation of the switch member, a -movable springtensioning member having a driving connection with the switch lever in the reverse direction aforesaid whereby the switchthrowing spring will be tensioned by the movement of said tensioning member in a direction reverse to the movement of the switch member and means for automatically disengaging the driving connection between lever operative in the reverse direction from the movement of the switch member, and means for automatically uncoupling the pawl, and ratchet connection between the tensioning member and switch lever when said switch lever is shifted by the tensioning member far enough in the reverse di rection to efi'ect a fresh engagement of the pawl and ratchet connection between the switch lever and switch member.

12. In an electric switch, a switch member rotatable in a forward direction only, an oscillating switch lever having, a pawl and ratchet connection with the switch member operative in' the movement of said lever in the, forward direction, a switch-throwing spring bearing against the switch lever in the forward direction aforesaid, an oscillating spring-tensioning member having a pawl and ratchet connection with the switchlever operative in a direction reverse to that of the switch member, means for disengaging the pawl and ratchet connection between the tensioning member and switch lever in such reverse movement of the tensioning member, a .spring for returning said tensioning member in the. forward direction and stops limiting the forward movement of the oscillating switch lever and springtensioning member.

13. In an electric switch, a rotatable switch member having ratchet teeth on its 1 upper face, an oscillating switch lever rest-- ing on the switch member and provided with ratchet teeth to engage those on the ,switch member and operative for rotating 7 the switch member in a forward direction,

a switch-throwing spring bearing against said switch lever in the direction of such forward rotation, an oscillating spring-tensioning member resting upon the switch lever and having a pawl and ratchet. connection therewith operative in a direction re- I the switch member to cause disengagement verse to that of the switch member, a spring bearin on the tensioning member to nor mally hold the pawl and ratchet connection between said tensioning member and switch lever engaged and means'for supporting the oscillating tensioning member at the end of the reverse movement thereof to thereby permit the switch lever when dropping to engage with a new set of ratchet teeth on of the pawl and ratchet connectionbetween the tensioning member and said lever.

14. In an electric switch, a switch member rotatable in a forward direction only, an oscillating'switch lever having a drivin engagement with the switch member 0 y in the direction of its rotation, a switch-throwing spring bearing against the switch lever in the direction of the switch rotation, an oscillating spring-tensioning lever having a driving engagement with the switch lever only in the reverse direction from the switch movement for thereby tensioning the switch-throwing spring, means for disconnecting the switch lever and tensioning lever at the end of the springtensioning movement of said tensioning lever to there by permit the spring through the switch lever to throw the switch member and means 'the lever and a pull chain havin right angle to said top portion, the said top dependent extension at the forward edge .thereof, the said top portion having an opening therein large enough to receive the end ball of a pull chain and a narrow slot extending forwardly therefrom and down into the dependent extension of the lever, a pull chain having the end ball thereof entered through said opening and droppeddown behind the extension aforesaid, a stop limiting the movement of the lever, a spring for returning the lever against said stop and t a member disposed beneath the opening in the lever in its position of rest against the stop totherebyprevent withdrawal of the.

end ball of the chain through said opening. 17. In an electric switch, an insulating base, a relatively stationary switch contact mounted on said base and having an upwardly-inclined spring contact portion, an arc-interrupting insulating shoulder at the upper end of said inclined contact portion and forming substantially a continuation thereof, the said spring contact projecting when unrestrained above the plane of the said, shoulder and free to yield under pressure downwardly into the plane of said arcinterrupting shoulder and a relatively movable spring-pressed switch contact bearing onsaid relatively stationary switch contact.

18. In an electric switch, a switch base provided with oppositely disposed upwardly inclined insulating ratchet teeth and with contact seats alternatin with said ratchet teeth, upwardly incline switch contacts mounted in the said seats,- arc-interrupting insulating shoulders at the upper ends of said inclined contacts substantially in the plane of the upper ends of said contacts, projecting beyond the contacts and forming substantially continuations of the said inclined contacts and a rotatable spring-pressed switch contact arranged to bear on the inclined contacts and insulating ratchet teeth and to traverse the insulating shoulders in passing from the contacts onto the insulating ratchet teeth.

19. In an electric switch, a switch base, a spindle mounted thereon, a switch member journaled on said spindle, a relatively strong close-coiled switch-throwing spring i x pvt on said spindle, means for connecting said switch-throwing spring with the switch member, 'a lever pivoted on the switch spindle having connection with the switchthrowing spring for tensioning the same journaled on said spindle, a switch-throwing spring coiled about the spindle and anchored to the spindle at one end, means for connecting the opposite end of said spring with the switch member, a spring tensioning lever pivoted on the spindle, a bushing non-rotatably engaged on the spin dle and surrounding the switch-throwing spring and a spring connected with said bushing at one end and with the tensioning lever at its opposite end.

21. lln an electric switch, a switch base, a spindle mounted thereon, a switch member journaled on said spindle, an outstanding anchorage 111 on the spindle, a switchthrowing spring coiled about the spindle and engaging said anchorage lug at one end, means for connecting the opposite end of said spring with the switch member, a lever pivoted on the spindle and having connection with the switch-throwing spring for tensioning the same, a bushing engaged on the spindle and slotted to receive the out standing anchorage lugand a spring connected with said bushing at one end and with the tensioning lever at its opposite end.

22. ln'an electric switch, a switch -base, a spindle mounted thereon, a switch member jo'urnaled on said spindle, an outstanding anchorage lug on the spindle, a switchthrowing spring coiled aboutthe spindle and engaging said anchorage lug at one end, means for connecting the opposite end of said spring withthe switch member, a lever pivoted on thespindle and having, connection with the switch-throwing spring for tensioning the same, said lever having a central sleeve portion fitting over the switch-throwing spring and slotted radially .to pass over the anchdrage lug on the spindle and a spring anchored to the spindle at one end and engaging the tensioning lever at its opposite end.

23. lln an electric switch, a switch base, a spindle mounted thereon, a switch member journaled on said spindle, a switch lever pivoted on the spindle and having a oneway driving connection with the switch member, a switch-throwing spring surrounding the spindle, anchored at one end to the spindle and connected with the switch lever at its opposite end, a spring-tensioning lever pivoted on the spindle with itscen tral portion resting on the switch lever and crowned up to accommodate the connection between the switch-throwing spring and switch lever and a spring anchored to the spindle at one end and connected with the tensioning lever at its opposite end.

24. lln an electric switch,a switch base, a spindle on the base, a switch contact pivoted on the spindle, a switch lever pivoted on the spindle above said contact and having a one-way driving connection therewith, a switch-throwing spring encircling the spindle abovesaid lever, anchored to the spindle at its upper end and connected with the lever at its lower end, a spring-tensioning lever resting on the switch lever and covering the connection between the throwing spring and switch lever, said tensioning lever having a central upstanding cylindrical portion surrounding the throwing spring to thereby form a bearing for the said lever and a. returning spring for said tensioning lever surrounding the .upstanding cylindrical portion. of said lever at its lower end and connected with the spindle at its upper end .25. lln an electric switch, a switch base, a

spindle on the base, a switch contact pivoted ing the connection between the throwing.

spring and switch level, said tensioning lever having a central upstanding cylindrical portion surrounding the throwing spring.

to thereby form a bearing for the said lever, a returning spring for said tensioning lever surrounding the upstanding cylindrical portion of said lever at its lower end and a 'end of said returning spring and secured to the spindle over the throwing spring to thereby provide a bearing for the upper end of the returning spring.

26. In an electric switch, a switch base, a spindle on the base, an-outstanding lug on said spindle, a lever pivoted on the spindle, a spring coiled about the spindle and having its lower end engaged with the said lever and a flanged bushing connected with the upper end of the spring, slotted to pass down over the outstanding lug and provided with a seat in its inner periphery to receive the said lug. I

27. In an electric switch, a switch base, a spindle mounted thereon, a rotatable switch contact .journalcd on said spindle, a switch lever pivoted on the spindle and having a one-way driving connection with the mov-- rotation, a switch throwing spring engaging thereof to assist in uncoupling the one-way said switch lever, a spring tensioning lever connection between the spring-tensioning having a one-way driving connection .with lever and the switch lever.

the switch lever in a direction opposite to FREDERIO BARR. that of the switch movement and an in- Witnesses: clined spring strip engaged by the tension- Ron'r. S. ALLYN, ing lever in the spring-tensioning movement E. BRADFORD: