US1996030A - Electric switch - Google Patents

Description

March. 26,. 1935. R Popp 1,996,030

ELECTRIC SWITCH Filed Nov. 10, 1933 Patented Mar. 26, 1935 PATENT OFFICE ELECTRIC SWITCH Rudolf Popp, Valparaiso, Ind.,` assignor to McGill Manufacturing Company, Valparaiso, Ind., a `corporation of `Indiana Application November 10, 1933, Serial No. 697,422

11 Claims.

My invention relates to yelectrical switches. vIt

relates more in particular to a relatively small size switch adapted particularly for controlling light circuits as', for example, in homes and offlces.

The principal object of the invention is the provision of an improved switch.`

Another object is the provision of a switch havl ing a small number of simple parts and capable ofeasy assembly.

Another object is the provision of an inexpensive switch which will have a long life.

Another object is the provision of improved means for connecting conductors to the switch.

Another object is ,the provision of an improved switch combination so arranged that the possi-I bility of short circuiting any portions thereof is substantially entirely obviated. f

Other specific objects and the details of the invention will appear from the following description taken with the accompanying drawing,

wherein v Fig. 1` is a perspective view of the improved switch of my invention;

Fig. 2 is an elevational'view showing a feature which permits easy attachment of conductors;

Fig. 3 is an elevational view with thel cover removed, the view looking along the line-B of Fig. 5;

Fig. 4 is a longitudinal staggered sectional view taken along the line 4-4 of Fig/5;

Fig. 5 is a staggered sectional viewk taken in general in a longitudinal direction along the line 5-5 of Fig. 3;

Fig. 6 is a transverse sectional view partly in elevation taken along the line 6-6 of Fig. 4;

Fig. 'l is a view of the housing of the switch which also functions` as a frame;

Fig. 8 is a perspective view showing the bridging contact members which perform their functions as will be shown; A

Fig. 9 is a large perspectiveview of the portion of the switch actuator: and

Fig. 10 is a perspective view of one of ther-sta# tionary contacts. f I' The switch comprises a frame 11, preferably molded from a suitable insulating material such `as a rubber compound or a condensation product. This frame also acts as a housing and Withua cover 12, the nature of which will be described more in detail as the description progresses, houses the entire switch apparatus. .y A generally cup-shaped recess 13 is provided and a center post 14 projects axially thereof and is integral with the frame or housing l1. Astem 16 is also formed y integral andis threaded to provide for mounting.

The switch includes a pair `of stationary contacts 17 shaped as shown in Fig. l() and secured in place by screws 18. The heads 17a of the sta- 5 tionary contact members rest in shallow wells v provided in the frame at either side of the cupshaped aperture therein. vvA slot forms a communication between these shallow well portions,

' and the cup portion and the stem portion 17h 10 lieV along'and within this slot so as Vtofhold the arcuate contact portions 17o in the lower part of` thecup portion but against the side wall thereof.

The bridging contact member 19 is shown in Fig.

8'. It lsforrned upv of a single piece of phosphor 15 bronze spring material and includes a pair of `contacting blades 19a and a center ring structure 19h which acts as a pawl, as will be shown. This bridging contact member is seated down over the center post 14 and rests in the bottom of 20 the cup-shaped `opening with the contacting blades 19a in line with the portions 17o of the stationary contact members.

I also provide a member 21 (Fig. 9) for actuating the bridging contact member. For short, I 25 term this member an actuator. It is cored to be threaded down overthe center post 14 and its bottom portion is provided with a number of longitudinally projecting ratchet teeth 22 adapted to co-operate, in a manner to be described, with 30 the upturned portion of the pawl member 19h of the bridging contact member. A coil spring 23 is disposed loosely within the actuatorvr and around the post 14. One end thereof is turned inwardly and projects into a slot 14a running 35 longitudinally of the center postand the other end is turned outwardly and engages in a recess 24 in the actuator. As will be noted clearly from Fig. 9, a lip 26 projects out over the recess 24 so as to extend over the projecting end of the spring 40 (see also Fig. 3).

For rotating the actuator, I provide a swivel ball type ofchain 2'7 which extends through the hollow stem 16 around a portion of the actuator, as shown in Fig'. 3, and engages in aslot or recess 45 28 formed longitudinally in the side wall of the actuator. Near this slot or recess 28. the outside surface of the actuator is finishedV with a series of grooves and ridges alternately arranged so as to permit the` successive swivel balls of the chain 50 to have more friction and so avoid direct pull on the end ball of the chain which is held in the "recess 28. In this manner, although the actuator `is comparatively small and `has acomparafv tively thinv sidewall, ample strength is obtained 5 Projecting laterally from the actuator, I pro? vide a stop 31 which engages a. shoulder 32'formed outside the edge of the cup-shaped portionkof the frame. Looking at Fig. 3, the'movement of the actuator from the position there shown'is ina clockwise direction. Accordingly, a portion of the frame is cut away to providea ledge 33 and* a correspondingopen space sufiicent to pass the stop 32. This makes it impossible to assemble the actuator in the frame or housing except-in the position shown in Fig. 3, because at other portions around the periphery of the cup-shaped portion the stop 32 cannot be accommodated.' At

the opposite end of this open space, another, shoulder is formed to limit the movement of' the actuator in response to pulling Vthechain;

Below the ledge w33 on one side of the frame and throughout the length of the' cup-shaped portion at the opposite side of the frame, four.'

ratchet tooth-like recesses 34 provide a final shape as'shownin Fig. 4. ',I'he result isa camlikeseries of surfaces over which theblades of the bridging contact membery move, whereby spring tension is built up in these bladesas they rotate and they drop vsharply off the .shoulders provided between successive cam surfaces. This produces a quick making and breaking of contact, that is to say, a snap makeand break action. These shoulders or steps between successive cam surfaces also have a ratchet action in `that the" bladesof the bridging contact member function as pawls to prevent the bridging contact member as a vwhole from being rotated in a counter-clock` wise direction when the actuator isreturned by its spring. n Y.

The terminal wells in which the screws 1,8k are housed are connected by a pairof slots 36 running through the frame. These are to pass conductors which, as shown, are connected to the,y

stationary contacts by'means of the screws 18. 'I'he cover 12 is secured in place byl an eyeletl type of rivet 37 which extends through the center post 14 and through the back of the housing or frame.

exposes theconductorattaching screws 18 read-Y ily without exposing any other portion of the switch. 'I'he cover is slightly recessed at 41-41 s to provide ample space for removing or loosening the screws when the cover is in the position of- Y ing therein, a pair of terminal wells inthe hous- Fig. 2.

It will be noted that the switch isv of exceedingly simple construction and has a very small number of parts. The housingor framel portion and the actuator are` both arrangedA to bemolded readily from' suitable insulatingl material. The stationary contacts and the bridging contact member arev readily formed' by stamping operations. .l l l In assembling the switch, the stationary contacts are dropped into position and secured with the screws 18. The bridging contact member is then grasped with a suitable jig to hold the spring 28 of the actuator.

blades slightly compressed, and dropped down into position at the bottom of the cup-shaped recess 13 and around thecenter post 14. The spring is then dropped into position in the actuator, with the downwardly projecting end engaging in the recess 24. 'I'he spring d actuator together are then threaded down o post with the inner projecting endof vthe spring engaging in the slot on the`lcenter post. vBefore the actuator is dropped d own a suillcient distance to engage the bridging `contact member, it is ror the center tated partially until the stop 31 on the actuator is 'in line4 with the shoulder 32 formed on the lframe or housing. :'At this position, it is forced vin the remaining distance and will then occupy the position shown in Fig. 3. y 'I'he pull chain is then` dropped through the stem 16, pulled out a suiiicient distance to circle the actuator, and the end bail of the chain inserted in the slot or recess Y Then chain isthen pulled taut, afterv which the cover is applied in position and rivetedV snugly against `the body. r

In operating theswitch, it is impossible for any kind' of' a short crcuitlto occur lor for thechain to be caught in Aany way. Sometimes in. switches4 of this character, if the chain is allowed to snap back, it will become lodged in against the contacts and cause a short circuit. rClearlythis is impossible with the construction which lI employ.

The manner in which the conductors areat-l tached and themanner inf which the switch functions during normal operation has been made clearin the body ofthe description.l

I have described my inventionV in detail andhave speciiicdetails shown but the scopeA thereof is defined by the appended claims.; 5 What I claim as new and desireto lprotect by Letters Patent of the United States is:

` 1. In a switch,` a housing bodily integrally formed of insulating material and having a generally cup-shaped openingr therein, a pair lof terminal wells in thevhousing spaced .at the,y side of the opening, a pair of stationary contacts, each having a portion supported in the ywells and each having another portion lying withina. slot at the edge of the opening and lying along .the lower side wall thereof,` a bridging contact member disposed in theopening, Vmeans for partially rotating the bridging contact member to alternately bridge and disconnect said stationary contacts, conductor attaching means engaging the stationary terminals and disposed in the wells, and a cover for'the housing opening pivotally supported on the housing and movable for. rend-- ering said conductor. attaching means accessible without uncovering the bridging contact member or operating means therefor.v l 2.` In a switch, a housing formed of insulating material and having-a generally cup-shaped openl bridging contact member disposed inthe opening,

means for partially rotating the bridging contact member to Valternately bridge and discon.

nect f said stationary contacts, conductor attaching screws disposed in said wells and engaging the stationaryV contacts, and a` coverpivotally secured to the housing at the center thereof and spaced from each other, a bridging contact, anv

actuator for the bridging contact, a peripheral slot on the actuator parallel' with the axis therev of, a plurality of peripheral corrugations adjacent the slot and parallel thereto, a swivel'ball type 'pull chain having a terminal pawl disposed in the slot and successive balls engaging in said corrugations, the chain extending partially around the actuator, and a spring urging .said actuator a direction opposite to the direction of rotation thereof in response to puling of the chain. 4

4. In a switch, a housing body integrally formed of insulating material and having a generally cup-shaped opening therein, a center post integrally forming part of the body and disposed in the opening, a pair of stationary contacts` carried at the side oi" the opening, a bridging contact member disposed at the bottom of the opening and surrounding the center post, an actuator journaled onthe opening and having portions adapted to successively engage a portion of the bridging contact member, Aa spring having one end secured to the post and the opposite end secured to the actuator, and a pull chain secured to the actuator and partially extending around the same whereby to rotate the actuator and bridging contact member against the action of said spring.

5. In a switch, a housing formed of insulating material and having a generally cup-shaped openfing therein, a center post formed of insulating material and having a longitudinally extending peripheral slot therein, stationary contacts at the side of the opening, a bridging contact member journaled around the post, an actuator extending around the post but spaced therefrom, a coil spring disposed between the post and actuator and having one end engaged in a slot in the actuator and the opposite end engaged in said slot in the post, a plurality of equally spaced projections on the actuator adapted to successively engage -Y a. portion of the bridging contact member, and

a pull chain engaging the actuator to rotate the same against the tension of said spring, said portion of the bridging contact member functioning as a spring pawl to permit return movement of the actuator by the spring without moving the bridging contact member.

l `6. In a switch, a housing body integrally formed of insulating material with a generally' cupshaped opening therein, a plurality of cam surfaces on the side walls of the opening interconnected by shoulders, all of which face in the same direction, stationary contacts lying along oppositely facing cam surfaces, a bridging Vcontact member `centrally disposed in the opening and' having a pair of spring blades engaging opposite cam surfaces, an upwardly extending spring projection integral with the bridging contact member, an actuator disposed in the opening and having a plurality of ratchet teeth adapted to successively engage the spring projection of the bridging contact member, and means for reciprocating the actuator through a radius equal to the length of the ratchet tooth and cam surfaces, ro-

tation of the actuator in one direction serving to rotate the bridging contact member, while on rotation in the opposite direction a bridging contact member is disengaged yand the blades thereof serve as pawls by engaging against the shoulders of the cam surfaces.

7. In a switch, a housing lformed of material and having a generally cup-shaped opening therein, a center post projecting from the housing into the opening, a pair of terminal wells formed i/n' the housing at the sides of the opening, stationary contacts having portions .secured in the wells and other portions extending along slots in the housing at the side of the opening with portions lying along the insidewall voi the opening, an integral bridging contact meminsulating l ber extendingL around the post with the blades adapted to engage stationary contacts to. bridge the same, and anv upwardly extending spring-like projection, an actuator jouiynaled on the post but spaced therefrom, a spring havingy oneend engaging in a slot inthe post and another end ,eng

gaging in a slot in the actuator, a pull chain having an end ball engaging in a slot in the actuator and partly extending around the actuator, and ratchet like teeth carried by the actuator and adapted to successively engage the spring' like' yprojection on the bridging contact member when the actuator is rotated.

8. In a switch, a housing formed of insulating material and having va, generally cup-shaped opening therein, a center post projecting from the housing into the opening, a pair of terminal Wells formed in the housing at the sides of the opening, stationary contacts having portions secured in the wells and other portions extending along slots in the housing at the side of the opening with portions lying along the inside wall of the opening, an integral bridging contact member extending around the post with the blades adapted to engage stationary contacts to bridge the same, and an upwardly extending spring-like projection, an actuator journaled on the post but spaced therefrom, a spring having one end engaging in a slot in the post and another end engaging in a slot in the actuator, a pull chain having an end ball engaging in a slot in the actuator and partly extending around the actuator, ratchet like teeth carried by the actuator and adapted to successively engage the spring-like projection on the bridging contact member when the actuator is rotated, an outward projection on the actuator, and shoulders on the housing for engaging the projection to limit the movement of the actuator in both directions, said projection engageable only between said shoulders whereby the actuator can be assembled in the housing only with a predetermined tension on the spring.

9. In a switch, a housing formed of insulating material and having a generally cup-shaped opening therein, a center post projecting from the housing into the opening, a pair of terminal wells formed in the housing at the sides oflsthe opening, stationary contacts having portions secured in the wells and other portions extending along slots in the housing at the side of the opening with portions lying along the inside wall of the opening, an integral bridging contact member extending around the post with the blades adapted to engage stationary contacts to bridge the same, and an upwardly extending spring-like projec- ,tion, an actuator journaled on thepost but spaced therefrom, a spring having one end engaging in a slot in the post and another end engaging in a slot in the actuator, a pull chain having an end pawl engaging in a slot in the actuator and partly extending around the actuator, ratchet like l the cover to the housing, and releasable engaging means between thecover and housing whereby said cover may be rotated to expose said` terminal wells and channels without uncovering the remaining portion of the switch mechanism.

10. In a switch, a'housing, switch mechanism in the housing, a terminal screw carried by the housing, a cover for the housing normally covering said terminal screw and switch mechanism, and a single swivel connection through a central portion of said cover, whereby said cover may be rotated to expose said screw without exposing said switch mechanism.

11, In a switch, a housing having a cup-shaped opening therein, switch mechanism mounted in the opening, a pair of terminal screws in the housing diametrically oppositely disposed relative to the switch mechanism in the opening, a flat cover of insulation material for the housing and covering said switch mechanism and terminal screws, said cover plate Ibeing centrally pivoted and rotatable to expose the terminal screws without exposing the switch mechanism.

RUDOLF POPP.

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