US2588793A - Rotary selector switch - Google Patents

Description

March 11, 1952 BARRY 2,588,793

ROTARY SELECTOR SWITCH Filed July 28, 1950 2 SHEETS-SHEET l INVENTOR ATTORNEYS March 11, 1952 RY 2,588,793

ROTARY SELECTOR SWITCH Filed July 28, 1950 2 SHEETS-SHEET 2 IN VENTOR ATTORNEYJ Patented Mar. 11, 1952 ROTARY SELECTOR SWITCH Leon G. Barry, Whippany, N. J., assignor to United States Instrument Corporation, Summit, N. J., a corporation of New Jersey Application July 28, 1950, Serial No. 176,465

7 Claims 3 This invention relates to rotary selector switches, and more particularly to a switch which is very small in size yet is capable of transferring a multiplicity of circuits between two or more positions.

The general object of the invention is the pro vision of a novel switch deck assembly for in' corporation in a multiple deck rotary switch of the character described, which switch deck comprises a stator having a plurality of fixed contact members associated therewith, and a rotor having a plurality of bridging contacts mounted thereon, the respective fixed and bridging contacts being secured and maintained in position by novel, simple and inexpensive means which facilitate the speedy and inexpensive assembly of the device into an integrated unit or package, any desired number of such units being then assembled on a shaft, together with an indexing mechanism, to complete a switch assembly for the control of the desired number of circuits.

A further object is the provision, in a switch deck unit of the character described, of a stator of molded insulating material, for example synthetic plastic material, having a plurality of upstanding projections disposed in circular arrangement, together with an equal number of fixed contact members each comprising a tubular portion adapted to encircle one of said upstanding projections, and a straight portion projecting radially outwardly of the molded stator for the connection ofa conductor thereto. Another object is the provision in a switch deck unit of the character described of a rotor of molded insulating material, such as a synthetic plastic material,

provided with a plurality of upstanding projections disposed in circular arrangement, together with bridging contact members of conductive metal encircling each of said upstanding projections, together with resilient means for urging said contact members outwardly into engagement with the fixed contacts of the stator.

A further object is the provision, in a switch deck unit of the character described in the preceding paragraphs, of a cover member permanently secured to the rotor after the bridging contacts are in place and therefore serving to maintain them permanently in position, and a cover member permanently secured to the stator after the stator contacts and rotor are assembled therewith, and serving to maintain the stator contacts and the rotor, which has already been permanently sealed as aforesaid, in position with regard to the stator, thus completing the aforesaid integrated unit.

Other and further objects, features and advantages will be apparent from the description which follows, read in connection with the accompanying drawings in which Figure 1 is a front elevation of a multi-deck switch, including operating knob, the several decks of which are constructed in accordance with the invention;

Figure 2 is a side elevation of the switch of Fig- Figure 3 is a front elevation of a switch deck unit with cover broken away;

Figure 4 is a sectional view on line 4-4 of Figure 3;

Figure 5 is a front elevation of a rotor according to the invention;

Figure 6 is a side Figure 5;

Figure 7 is a sectional view on line Figure 3;

Figure 8 is a sectional view on line Figure 3;

Figure 9 is a sectional view on line Figure 3;

Figure 10 is a perspective view of a bridging or rotor contact;

Figure 11 is a perspective view of a fixed or stator contact; and

Figure 12 is a perspective view of a bifurcated leaf spring for urging the bridgin contacts outwardly.

In order to facilitate an understanding of the invention, reference is made to the embodiment thereof shown in the accompanying drawings and detailed descriptive language is employed. It will nevertheless be understood that no limitation of the invention is thereby intended and that various changes and alterations are contemplated such as would ordinarily occur to one skilled in the art to which the invention relates.

Referring to Figures 1 and 2, a complete switch assembly employing switch deck units according to the present invention comprises any desired number of switch decks l0 mounted on shaft H on which are also mounted an indexing mechanism I 2 and an operating knob l3. The indexing mechanism may be of any suitable type, but it is preferred to employ a mechanism such as described and claimed in my ccpending application Serial No. 174,879, filed July 20, 1950, which was issued as Patent No. 2,579,169 on December 18, 1951. The several switch decks and the indexing mechanism are secured together by means of bolts l4 and nuts I5, and the entire assembly may conveniently be mounted in a panel 16 by elevation of the rotor of means of threaded bushing I1, nut l8 and washer l8, the panel being clamped between the latter and the hub portion H) of the indexing mechanism.

Referring now to Figures 3 and 4, the switch deck unit comprises generally a stator 20 and rotor 2| which are preferably molded of insulating material such as a synthetic plastic material, for example, of molded nylon. The stator 29 is formed with a central circular aperture into which fits the hub portion 22 of the rotor 2|, the latter being telescoped into the stator 20 as seen in Figure 4. The rotor is formed with a central squared aperture 23 therethrough for reception of a squared portion of the shaft The first switch deck l behind the indexing mechanism |2 is insulated therefrom by means of a phenolic or other separator plate 25.

The stator 20 is formed to provide a circular series of upstanding, preferably cylindrical projections 29 corresponding to the number of fixed contact members which it is desired to employ in the switch deck unit and each projection 26 is provided with a contact member 21, preferably of resilient metal, formed to provide a tubular portion 28 which encircles the cylindrical projection 26 and a straight portion 29 which extends radially outwardly from the tubular portion. The straight portion 29, in the illustrated embodiment, comprises two prongs consisting in the respective ends of the metal strip of which the contact member consists, which ends lie parallel and adjacent each other, the tubular portion 28 of the contact member being formed of the material in the central portion of said strip. Preferably, the straight portion 29 is perforated as at 39 (Figure 4) to facilitate the soldering of a conductor thereto.

The stator is also provided with upstanding projections 3| extending inwardly from the periphery of the stator and terminating in a narrow pointed portion extending between adjacent fixed contacts and serving to increase the length of the leakage or creepage path between adjacent contacts. The straight portions 29 of the respective contacts extend outwardly through slots between adjacent edges of adjacent projections 3| and, due to the spring action of the resilient material of which they are made, frictionally engage the respective edges of said slots.

The stator is also formed to provide four anguraly spaced projections or bosses 32 the radially inner portions of which correspond in shape to the radially inner portions of the projections 3!, and the radially outer portions of which are provided with through apertures 33 to receive the bolts I4. The bosses 32 are formed to provide short upwardly extending sleeve portions 34 (Figure 8) for a purpose to be later described.

The rotor 2| as best seen in Figure 5, is circular in outline and is formed with a hub 35 which extends to substantially the same height as the projections 3| and contact members 21 of the stator. Four arms 36 extend radially outward from the hub 35 and provide therebetween the substantially semi-circular coves 31,

the respective arms 36 being notched on either side, as at 35', at pointsnear their outer ends, to receive the respective ends of bifurcated leaf springs 39 (Figure 12).

Lying within each cove 3'! of the rotor is an upstanding generally oval projection 39 pro 'vided substantially centrally of its upper surface with a small cylindrical boss 40. The projec-- tions 39 carry the bridging contact sets 4|, each contact set comprising two rings 4|, 4|" (Figure 10) of conductive metal. The rotor contacts as well as the stator contacts are preferably provided with laminated silver coatings to improve their conductivity, and to reduce wear and erosion. Each of the rings 4|, 4|" is separately urged radially outwardly by one of the bifurcations of the leaf spring 38, which is retained between the innermost point of the bridging contact set 4| and the notches 36' formed in the respective sides of the arms 36.

After the bridging contacts 4| together with the leaf springs 33 are assembled on the rotor, a ring or cover 42 of phenolic material or other insulating material is assembled to the rotor by means of the bosses 49 formed on the tops of projections 39, the bosses extending through corresponding apertures in the cover 42 and being headed over by any suitable means,

secured together, and the rotor cannot become displaced from the stator, nor can any of the fixed or rigid contact members, or leaf springs 38, become dislodged. The cover 43 is preferably provided with punched, inwardly extending shallow bosses 44 (Figure 4) which project into the outer ends of the tubular portions 28 of the fixed contacts thus cooperating with the projections 26 in firmly anchoring the fixed or stator contact members. The switch deck thus becomes an integrated unit and may be manufactured, sold, transported and installed as such, without danger that any disarrangernent of the parts may take place.

From the foregoing description it will be apparent that the present invention provides a simple, inexpensive, easily assembled and foolproof switch deck unit for rotary switches, as well as one that is especially efficient, due to the self-cleaning action of the rotary contacts 4|, and the firm yet yielding engagement between the bridging contacts and fixed contacts, secured by virtue of the leaf springs 38. The whole device may be made to occupy very little space, a switch deck such as that illustrated in the drawings, and provided with twelve fixed contacts, having an overall diameter of approximately one inch. Such a switch, naturally, conserves a great deal of panel space in installations in which a multiplicity of switches are necessary.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A rotary switch unit comprising a stator and a rotor, said stator being formed of molded plastic and being provided with a plurality of upstanding projections arranged in a circle, and a contact member associated with each said projection and having a tubular portion encircling said projection and a straight portion projecting radially outwardly of said stator, said rotor being concentric with and of smaller diameter than said stator, and being formed of molded plastic and generally circular in outline, and being provided with a plurality of upstanding projections spaced about its periphery, a bridging contact mounted on each said rotor projection and having an outer dimension at least equal to the distance between two adjacent stator contacts, spring means urging said bridging contacts outwardly to engage said stator contacts, means permanently secured to said rotor for holding said bridging contacts in position, and cover means permanently secured to said stator for holding said stator contacts and said rotor in position, the whole constituting a permanently integrated unit.

2. The combination of claim 1, said stator being formed with a plurality of peripherally disposed upstanding projections alternating with said stator contact members and increasing the leakage path therebetween.

3. The combination of claim 2, said peripher: ally disposed projections being closely spaced to provide narrow slots therebetween, said straight portions of said stator contacts projecting outwardly through said slots.

4. The combination of claim 3, each said stator contact having two substantially parallel straight portions projecting through said slot and being formed of resilient metal, said straight portions being urged apart by spring action to engage the edges of said slot.

5. The combination of claim 1, said last means having a plurality of circularly arranged downwardly projecting bosses engaging within said tubular portions of said stator contact members.

6. The combination of claim 1, each said bridging contact comprising two generally oval rings adapted to fit over one of said rotor projections in superposed relation.

7. The combination of claim 6, means comprising a bifurcated mounted behind each said bridging contact, one of said bifurcations engaging each of said rings and urging the same radially outwardly.

saidspring leaf spring LEON G. BARRY.

REFERENCES CITED UNITED STATES PATENTS me Date Number Na Smith Sept. 11, 1945

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