US3184559A

US3184559A - Multi-contact rotary electric switch with resiliently biased conductive pins

Info

Publication number: US3184559A
Application number: US20004/60A
Authority: US
Inventors: Oxley Robert Frederick
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-06-07
Filing date: 1960-06-07
Publication date: 1965-05-18
Anticipated expiration: 1982-05-18
Also published as: GB952854A

Description

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May 18, 1965 yf., y L ji United States Patent O MULTI-CONTACT ROTARY ELECTRIC SWITCH WITH RESILIENTLY BIASED CNDUCTIVE PINS Robert Frederick Oxley, Priory Park, Ulverston, England Filed .lune 5, 1961, Ser. No. 114,849

Claims priority, application Great Britain, June 7, 1960,

1 Claim. (Cl. 200-11) This invention relates to rotary switches. Such switches may be used for many purposes for selectively completing a number of different circuits.

It is an object of the invention to provide a rotary switch of simple construction and one which enables many different connections to be easily made from outside of the switch. It is another object of the invention to provide a rotary switch which can be of small size.

According to the present invention a rotary switch comprises a sleeve having a wall, one or more series of radially disposed conductive pins arranged on a circumference and extending through said wall, a switching member mounted for rotation within said sleeve about the axis of said sleeve, and conducting means mounted on said switching member for selective engagement with at least one pin or with at least one pin from each of said series. The sleeve may be polygonal but is preferably cylindrical.

Preferably each of the pins is resiliently secured in a hole in the sleeve. One way in which this can be achieved is for each pin to extend through a resilient insulating bushing secured in a hole in the sleeve.

One example of the invention and a modification thereof will now be described with reference to the accompanying drawing, in which:

FIGURE 1 is a longitudinal section of the rotary switch;

FIGURE 2 is an end view of the rotary switch in the direction indicated by the arrow II shown in FIGURE l;

FIGURE 3 is a cross section on the line lll-III in FIGURE l; and

FIGURE 4 is a cross-section similar to FIGURE 3 of a rotary switch of the same general construction as that shown in FIGURES 1 to 3 but in which the pins are secured in the sleeve in a different manner.

As illustrated in FIGURES l, 2 and 3, the rotary switch comprises a body having two

cylindrical portions

11 and 12 spaced by a hexagonal portion 13. The smaller diameter cylindrical portion 11 is screwthreaded and the rotary switch may be secured in a panel by entering this portion through a hole in the panel and tightening a nut on 'the screwthread. A sealing ring 14 is provided to ensure hermetic sealing between the hexagonal portion 13 and the panel.

The body 10 carries a coaxial spindle 15 to the outer end 16 of which a knob may be attached for rotating the spindle. At its inner end the spindle carries an index plate 17 which rotates with the spindle. The index plate 17 has twelve evenly spaced apertures 18 arranged around a circle and these apertures may be engaged by a pair of balls 19 which are carried in axial drillings 20 in the body 10. The balls 19 are biased towards the index plate and into the apertures 1S by springs 21 contained in the drillings 20 and the thrust on the spindle produced by the springs is taken by a nylon washer 22 between a ange 23 on the spindle and a shoulder 24 in the body 10. The spindle 15 is also provided with two circumferential grooves 25 which accommodate sealing rings 26 which seal the bore in the body 10.

Secured to the larger diameter cylindrical portion 12 of the body 10 is a rigid sleeve 30 the open end of which is closed by a block 31 of polytetrailuoroethylene 3,l84,559 Patented May 18, 1965 (P.T.F.E.). The sleeve is provided with four circumferential rings of evenly spaced apertures, the apertures also being arranged in axial rows. Each aperture contains a bored bushing of P.T.F.E. and comprises a cylindrical portion 51 of the same diameter as the apertures and a flange 52. The cylindrical portion passes through the aperture from the inside of the sleeve 30 and the flange rests against the inside of the sleeve. Into each bushing is passed from the inside a pin 57 of metal, for example silver-plated brass, and of circular cross section. Each pin has a central portion 53 of slightly greater diameter than the bore in the bushing 50 and an outer end portion 54 of approximately the same diameter as the central portion. At the inner end of the central portion 53 there is a wedge-shaped tlange 55 while between the central portion 53 and the outer end portion 54 there is a similar but slightly larger wedge-shaped ange 56. The pin 57 is pushed into the bore of the bushing from inside the cylinder until the inner enlargement 55 lies partly within the flange 52 of the bushing and in this position the wedge-shaped flange 56 between the central portion and the end portion of the pin will lie within the cylindrical portion 51 of the bushing on the outside of the sleeve 39 and will expand the bushing so that the bushing cannot be withdrawn into the cylinder. Fittings of this description are described and claimed in United States Patent No. 2,911,460 to Robert Frederick Oxley, dated November 3, 1959,

For the sake of simplicity, only two bushings S0 and associated pins 57 have been shown in FIGURE 3 but it is to be understood that there are, in fact, twelve such pins and bushings in the series shown in FIGURE 3. Each of the other three rings of apertures in the sleeve 39 likewise accommodates a series of twelve associated pins and bushings.

The lower end (as viewed in the drawing) of the spindle 15 carries a switching member 32 which consists of a generally cylindrical block of P TFE. and which rotates with the spindle. Extending through the switching member are four diametrical drillings 33 whose axes are respectively in the planes of the series of pins and bushings. Adjacent end of adjacent pairs of drillings 33 accommodate the ball-shaped ends 34 of dumb-bell shaped conducting members 35. Each end 34 is biased radially outwards by means of a spring 36 which is contained Within the respective diametrical drilling 33. Each diametrical drilling 33 thus contains two springs 36 which are separated from one another by an insulating block 37.

The switching member 32 is provided with three radial flanges 40, 41 and 42 which engage the ilanges of the adjacent rings of bushings and help to locate the switching member.

Suitable external connections are made to the projecting end portions 54 of the pins 57. It will be seen that in any rotational position of the switching member 32 in which the balls 19 engage in apertures in the index plate 1'7 four pairs of pins 57 will be interconnected but ot' course it is not necessary for external connections to be made to all the pins and accordingly a large number of combinations of circuits can be selected by the rotary switch described.

The rotary switch illustrated in FIGURES l to 3 may be modified by forming the sleeve 30 from resilient insulating material such as P.T.F.E. and dispensing with the bushings 50. In such a modified embodiment which is illustrated in FIGURE 4, the pins are pressed directly into the sleeve 30 which retains the pins by virtue of its own resiliency.

Many modifications of the constructions illustrated may be made. For example only one or more than two conducting members 35 may be provided for interconnecting pins from adjacent series and the conducting members may take many different forms.

What I claim as my invention and desire to secure by Letters Patent is:

A sealed miniature rotary switch comprising a housing including an open-ended cylindrical side wall member and end Walls closing the open ends of said side wall member to form a closed cylindrical chamber, one of said end walls having means for securing said housing to a supporting panel, said side wall member having a plurality of apertures of circular section extending through it, the apertures being arranged in at least two spaced series, each said series comprising at least twelve apertures, the longitudinal axes of the apertures of each series lying in a common plane perpendicular to the longitudinal axis of said cylindrical side wall member and being radial with respect to the longitudinal axis of said cylindrical side wall member, each aperture containing a bushing, each said bushing having a base, a head portion too large to pass through the aperture and engaging the inner wall surface of said cylindrical side wall member around the aperture and a reduced portion which extends through the aperture and part of which projects outwardly beyond the outer wall surface of said cylindrical side wall member, each said bore having an elongated electrically conductive pin extending through it, each pin having a head portion engaging the head portion oi the respective bushing, a circumferential enlargement lying within said part of the reduced portion of the respective bushing which projects beyond the outer wall surface of i said cylindrical side wall mc'nber and expanding the said part to prevent radially inward movement of the respective bushing through the aperture in which it lies, and a terminal portion which extends radially outwardly beyond the radially outer end of the respective bushing; and a rotor including a rotary shaft mounted for rotation in the end wall of the housing having said securing means, sealing means sealing between said shaft and said end wall, a cylindrical rotor of insulating material rigidly secured to said rotary shaft within said closed cylindrical chamber, said closed cylindrical chamber and said rotary shaft and said rotor being coaxial, axially cxtending grooves in the outer cylindrical surface of said rotor, an elongated conductive member in each of said groove, and spring means urging said conductive members radially outwards of the rotor into selective contact with the heads of said pins.

References Cited by the Examiner UNITED STATES PATENTS 2,418,616 4/ 47 Batcheller 20D-6 2,599,314 6/52 Bobb 20C- 166 2,774,812 12/56 Clark 174-153 2,911,460 1l/59 Oxley 174--153 FOREIGN PATENTS 600,344 4/48 Great Britain. 827,984 2/60 Great Britain.

BERNARD A. GILHEANY, Pri/'nary Examiner.

MAX L. LEVY, Examiner.