US2503885A - Selector switch - Google Patents

Description

1l, Q E, NYGREN 2,503,885

SELECTOR SWITCH Filed April 10, 1948 3 Sheets-Sheet l 8% www A TWO/emi@ C. E. NYGREN SELECTOR SWITCH April 11, 195o 3 Sheets-Sheet 2 Filed April 1o, 1948 INVENTOR. CD1/,91152555 /I/V/EE/V April l1, 1950 c. E. NYGREN 2,503,885

SELECTOR SWITCH Filed April 10, 1948 3 Sheets-Sheet 3 IOZv INVENTOR. CHARLES E. NYGRE/y ABY A Tron/Vey Patented Apr. 11, 1950 SELECTOR SWITCH Charles E. Nygren, Milwaukee, Wis., assignor to Globe-Union Inc., Milwaukee, Wis., a corporation of Delaware Application April 10, 1948, Serial N0. 20,317

(Cl. ZOO-11) 3 Claims.

This invention relates to improvements in selector switches for multiple-circuit control, and particularly to indexing and position return mechanisms for such switches.

The present application is a continuation in part `of the application of Charles E. Nygren for improvements in a Selector switch, iiled August 29, 1947, Ser. No. 771,297, and abandoned April 24, 1948.

Switches of this type are shown and described in Patentsv Nos. 2,291,516 and 2,291,517, for "Selector switch, issued July 28, 1942, to Globe- Union Inc., the assignee of this application. The switches of these patents used a spring-biased detent engageable with indexing lugs for the in dexing mechanism `and a separate position return spring. While such switches operate satis iactorily, the detent and lugs rapidly wear which unduly shortens the useful life of the switch. Also, the incorporation of a spring for the detent, as well as a return spring, unnecessarily multiplies the number of parts and increases manufacturing cost of the switch.

It is therefore an object of this invention to provide a selector switch having an indexing mechanism which will withstand wear better than those now in use and which will also function as a position return.

Another object of the invention is to provide a. selector switch in which the interchange of a single part adapts the switch for indexing in every position or for indexing in some positions and spring returnable to an indexed position from other positions upon removal of manual force.

And a further object of the invention is to provide a simple, compact selector switch which may be mounted singly or in groups for effective and reliable operation of a large number of circuits over longer periods of time than was possible heretofore by switches of the present type.

These objects are obtained by providing a cam which rotates with the rotor of the switch and a cam follower roller carried by a spring-biased lever pivoted on the supporting plate of the switch. The cam may be formed in varying shapes as shown for the purpose of either indexing the rotor in each of a plurality of selected y positions or indexing it in some of the selected. positions and returning it from other of selected positions to an indexed position. The cam may be either internal or external in design. If the rotor is mounted for limited reciprocal rotation within angular limits of say 60 (such as is the case when the rotor is operated by a lever which projects radially through a slot in the base.) an internal cam is most adaptable. If the rotor has reciprocal rotation through angular movements of say 150 or more (such as is the case when the rotor is operated by a laterally projecting shaft) an external type of cam is most adaptable.

In either event, a single spring functions to perform the indexing as well as the position return action of the rotor. The cam follower roller and its lever may be incorporated within the narrow contines of the switch-supporting bracket and still provide suilicient bearing surface of a low frictional nature to withstand wear and thus lengthen the useful life of the switch.

The novel features, which areconsidered characteristic of the invention, are set forth with particularity in the appended claims. vention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, in which:

Fig. 1 is a top plan view of a switch embodying the present invention with some of the contacts omitted for sake of clarity in illustration;

Fig. 2 is a view in front elevation of the switch viewed in Fig. 1;

Fig. 3 is a sectional view taken on the line III- IU of Fig. 2;

Fig. 4 is a fragmentary front elevational view of the switch viewed in Fig. 1 with portions broken away for sake of clarity in illustration;

Fig. 5 is a top plan view of the hanger bracket, bell crank lever and cam follower roller comprising elements of the indexing and return position mechanism;

Fig. 6 is a view in front elevation of the mechanism viewed in Fig. 5;

Fig. 'T is a View in elevation of the bell crank lever shown in Figs. 5 and 6;

Fig. 8 is a view in elevation of the rotor lever incorporating one type of internal cam;

Figs. 9 and 10 are views in front elevation of rotor levers incorporating modified forms of internal cams;

Fig. 11 is a top plan View of another modication of a switch embodying the present inven tion;

Fig. 12 is a sectional view taken on the line XII- XII of Fig. 1l; and

Fig. 13 is a view in front elevation of a modified form of external cam.

Referring to the drawings by reference numerals, many of the elements of the modifications of the switch herein described are shown and described in detail in the aforementioned patents and reference is herein made to such patents for such detailed description. In general all modications of the switch include a stator 2l of insulating material, which carries iixed contacts 28 and 2S varying in number and location depending upon the nature of the circuit to be controlled, and a rotor 33 of insulating material rotatably mounted within the contines of the stator and carrying contact members 34 and 35 which slidably selectively engage with the xed contacts 28 and 29 upon rotation of the rotor.

In the modifications shown in Figs. 1 to 4, inclusive, the stator 21 is substantially half an ellipse because the rotor 33 is confined to angular movement within limits of approximately 60. In the modification of Figs. 11 and 12 the stator 21 is substantially a full ellipse as the rotor may have angular movement of 150 or more. Stators of the full ellipse type are shown and fully described in Patent No. 2,186,949, issued January 16, 1940, to K. C. Allison, et al., for Electric switch.

Referring now to the modification viewed in Figs. 1 to 10, inclusive, the stator and rotor are carried in a mounting l5 having a base i6 and an integral side plate I1. A supporting plate I3 staked to the base I6 completes the mounting. The side plate l1 has end ears 22 to which the stator 21 is secured and a central ear 23 which serves as one support for the rotor pivot 32. The other end of pivot 32 is supported in the supporting plate i8. An operating lever, including a body portion 35, a tang 31, and two wing portions 38, is rotatably mounted on the pivot 32 with the tang 31 extending through a slot in the base I5. Both the lever 35 and the rotor 33 are fixed on a common hub which rotates on the pivot 32. Thus the swinging of the lever by a handle 38 controls reciprocal rotation of the rotor 33.

The indexing of the rotor 33 in selected positions, and the return of the rotor from other positions to an indexed position, are controlled by a cam and a spring-biased cam rider. Various shapes of internal cams are shown in Figs. 8, 9 or 10. The cam shape shown in Figs. 2, 3, and 8 has curved surfaces 43 and 44 defining the end limits of cam travel and sloping surfaces 45 and 46 rising from a low point which defines' a central indexed position. A cam follower roller 52 rolls on the surfaces 45, 46. It is mounted on one end of a bell crank lever 58 pivoted at '5| on the supporting plate I8. A lateral ear 53 on the other end of the bell crank 5l) extends over the edge of the supporting plate I8 and is attached to one end of a helical spring 51, the other end of such spring being secured to an ear 58 on the supporting plate I8. Thus the switch mounting, spring, and bell crank lever are closely organized and compactly arranged within the limited space available. Withthis construction the switch may be manually moved to either of two end positions and manually held there, but as soon as the manual pressure is released the rotor will move to the central position under the action of the cam follower roller 52 pressing against the sloping surfaces 45 or 46. Movement of the rotor to either end position may be limited by engagement of the tang 31 with the ends of the slot or by the roller 52 engaging with the surfaces 43 or 44.

If it is desired to provide a switch in which the rotor is indexed and held in one end position and is returnable to center indexed position from the other end position upon removal of the manual' pressure, the internal cam is shaped as shown in Fig. 9. In such cam the curved surface 54 and the sloping surface 65 correspond to the curved surface 44 and sloping surface 46, respectively of the cam of Fig. 8. The low point between rise 61 and surface 65 defines the center indexing position, while the low point between sloping surface 63 and rise 61 defines may define a limit to such end position while rise 65 completes the internal cam. With the cam of Fig. 9 the cam roller 52 will roll over the rise 61 and index the rotor in either the center or left end position. However, to hold the rotor in the right end position, manual force is necessary to keep the roller 52 from riding down the cam surface 65 and forcing the rotor to center position. Thus the rotor has one position in which it may be positively indexed, a second position into which the rotor may be moved and manually held, and a central position to which the rotor automatically returns from such manually held position.

In the modification shown in Fig. 10, the cam has three low surfaces 1|, 12, and 15 which define three indexing positions. These low surfaces are separated by rises 15 and 11. 'Hence the rotor may be indexed and held in either one of three indexing positions. Manual pressure, however, is necessary to overcome the force of the spring and move the rotor out of one position to a point at which the roller 52 rides over either the rise 16 or 11 and to cause the rotor to move into an adjacent indexing position.

Referring now to the modification viewed in Figs. 1l to 13, inclusive, the stator and rotor unit are mounted on a supporting plate by means of laterally projecting bolts 8| carried by such plate. The stator 21 is spaced from the plate 80 by tubular spacers 82 on the Shanks of the bolts 8l. It is thus possible to mount a plurality 'of stator and rotor units in spaced relationship on the bolts 8|. However, for the purpose of this invention 'only one stator and rotor unit is shown. Av shaft 83 is rotatably carried in a bearing 84 fixed to the plate 80.` Opposed ats 85 are milled on the shaft 83 to non-rotatably hold the rotor and the cam body. It is .also desirable to mill a single flat 86 on the outer end "of the shaft 83 so that it may non-rotatably rec eive and hold an operating knob (not shown). In this modification, if there were no other restriction the rotor would have angular movement through 360. However, for practical purposes the angular movement of the rotor is limited as hereinafter described.

The indexing of the rotor in selected positions, and the return thereof from other non-indexing positions to indexed positions, are accomplished, as in the previous modification, by a cam and spring-biased cam follower roller, the construction of which is similar to that previously described. However, in this modification the cam body 81 is staked to the shaft 83 between the plate 80 and the rotor stator unit and there is no projection tang. The cam body because of greater angular movement has an external cam rather" than an internal cam. As in the previously described modification there is a cam follower roller 88 which rides on the external cam surfaces. However, this roller is mounted intermediate the ends of a lever 89, the inner end of which is pivoted at 9U to the plate 88. 'Ihe lever is spring-biased to urge the roller toward the cam by a spring 9i connected to the free end of the lever 89 and to an ear 92 projecting from the plate 89. Operative space for the spring 9| may be provided by cutting back a portion of the plate 89, as indicated at 93. As is shown in Fig. 11, the lever 89 is offset so that its free end lies substantially in the plane of the plate 80 while the central portion is spaced from such plate to provide for freedom of movement. 1

The form of the external cam shown in Fig. 12 has three low points 94, 95, and 96, which define three positions in which the rotor will be positively indexed. In addition, this cam has two sloping surfaces 91 and 98 which when acted upon by the cam follower 88 cause the came and the rotor to rotate from either of the two end extremes of travel to either the index positions 94 or 96 whenever manual holding force is removed from the shaft 8B. The two extremes of travel or end positions are determined by the abutment between a lug 99 formed from the plate B0 and either of the edge portions or |0| formed on the cam body 8l. A selector switch with such a cam can be manually moved to and manually held in either of the two extreme positions. Upon release of the manual force the rotor will snap back to an adjacent indexed position. As is the case with the cam of Fig. 10-, the rotor may be manually moved out of one indexed position to a point at which it will snap into an adjacent indexed position.

The cam shown in Fig. 13 has only one low point |02 and two sloping surfaces |03 and |04. This cam operates substantially identical with the cam of Fig. 8. When this cam is substituted for the cam of Fig. l2, the switch will always be movable to the central indexed position. It may be manually moved and forcibly held in either of two extreme positions, such extremes being determined by the relative angular positioning of abutting edges |00 and |0|. A selector switch provided with this cam operates in substantially the same manner as the selector switch provided with the cam of Fig. 8.

A common feature of all of the modifications is that a single spring associated with a single cam follower roller performs in conjunction with a cam of desired design both the function of indexing the switch rotor and spring-biasing the switch rotor so that it will automatically return from a non-indexed position to an indexed position upon the release of the manual force moving the rotor to non-indexed position. In all modifications the spring and lever for the cam follower roller are so structurally related to the mounting bracket or plate that a, minimum amount of space is required therefor. With the type of construction described, it is also possible to use hardened parts for the Wearing surfaces of both the cam and the cam follower roller and the friction therebetween may be kept to a minimum and the effective life of the switch increased.

Although only several embodiments of the invention are shown and described herein, it will be understood that this application is intended to cover such other changes or modifications as come within the spirit of the invention or scope of the following claims.

I claim:

1. A movable contact switch comprising a bracket with a mounting base portion and a support portion, a switch stator mounted on said support portion, a plurality of fixed contacts mounted on said stator in insulated relation, a supporting plate fixed on said base portion and extending substantially parallel to said support portion, a common hub rotatably mounted between said support portion and said supporting plate, a switch rotor fixed on said hub, a plurality of contacts mounted on the rotor in insulated relation,

a lever fixed on said hub and extending through 7 said base portion, said lever having an aperture with a plurality of cam surfaces, a bell crank lever pivoted on said supporting plate, a cam follower roller on one end of said bell crank lever engageable with said cam surfaces, and a, spring urging said bell crank lever to cause said roller to be in engagement with the cam surfaces, said cam surfaces and said roller acting to index said switch rotor and cause its movement over a desired range.

2. A selector switch comprising a mounting member, a stator of insulating material having fixed contacts and carried on said member, a rotor of insulating material associated with said stator and having contacts which selectively engage said fixed contacts, said rotor being rotatable with respect to said stator to a first extreme position, a central position and a second extreme position to establish different contacts, a bearing fixed t0 said member, a shaft member rotatably carried in said bearing and having a driving connection with said rotor, said shaft member being manually movable to bring said rotor into selected ones of said positions, and indexing mechanism for indexing and holding said rotor in said central position and said first extreme position and acting to return said rotor to said central position from said second extreme position upon removal of manual pressure holding said shaft member and rotor in said second extreme position, said mechanism including, a cam mounted on one of said members and having a rise between a low point delining said central position and a lovv point defining said first extreme position, Said cam also having a surface defining said second extreme position, a cam follower mounted on the other of said members, and spring means cooperable with said follower to return said rotor to said central position from said second extreme position upon removal of manual pressure holding said shaft and rotor in such second extreme position.

3. In a selector switch having a contact carrying stator and rotor relatively movable to a plurality of positions for establishing different contacts, means for indexing said stator and rotor in a first position and moving said stator and rotor out of a second position in which said stator and rotor are manually held, comprising a cam and cam follower relatively movable in synchronism with the relative movement of said stator and rotor, said cam having a low point in which said follower rests to index said stator and rotor in said first position, said cam having a sloping surface up which said cam follower rides as said stator and rotor are moved to said second position, abutment means to limit the relative movement of said cam and rotor when said stator and rotor reach said second position, and spring means for urging said cam follower into engagement with said cam with sufficient force to cause said cam follower to ride down said sloping surface upon removal of manual pressure holding said stator and rotor in said second position whereby a single spring operating through said cam and cam follower` functions to index said switch and move said switch out of a manually held position.

CHARLES E. NYGREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,291,516 Wolff July 28, 1942 2,411,013 Warnke Nov. 12, 1946 2,418,564 Wallace Apr. 8, 194'7 2,444,471 Samiran et al July 6, 1948

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