US3511952A - Electrical switches - Google Patents

Description

' May 12, 1970 I WILKINSON 3,511,952

ELECTRICAL SWITCHES Filed April 11, 1968 )Oa l 16 Z5 Z4 INVE NTOR b BY 61W,

ATTORNEYS United States Patent 3,511,952 ELECTRICAL SWITCHES Norman Wilkinson, Fence, Burnley, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, Eng- US. Cl. 200--166 3 Claims ABSTRACT OF THE DISCLOSURE An electrical switch includes a relatively fixed body having a rotor supported thereon for angular movement between a plurality of angularly spaced positions, to open or close electrical contacts. An operating member is pivotally supported on the rotor for pivotal movement about an axis at right angles to the axis about which the rotor moves relative to the body, and further electrical contacts are provided, operable by said pivotal movement of the operating member relative to the rotor. There are further provided detent means acting between the body and the operating member for maintaining the operating member in either a position wherein said further contacts are open, wherein a position wherein said further contacts are closed, irrespective of the angular movements of the rotor relative to the body.

,. the kind specified, there are provided detent means acting between the body and said member for maintaining said member in either a position wherein said further contacts are open or in a position wherein said further contacts are closed, irrespective of said angular movements of the rotor.

One example of the invention is illustrated in the accompanying drawings wherein FIG. 1 is a diagrammatic representation of an electrical switch and FIG. 2 is a diagrammatic plan view of the switch shown in FIG. 1 I

with parts thereof omitted for clarity.

Referring to the drawings, the switch includes a hollow cylindrical body 10 which is moulded in synthetic resin and which has a rotor 12 also moulded in synthetic resin mounted for angular movement therein between a pair of extreme positions. Associated with the body 10 and the rotor 12 are a plurality of sets of electrical contacts (not shown). Detent means 11 act between the rotor 12 and the body 10, the detent means 11 serving to maintain the rotor 12 against accidental movement relative to the body 10, in any one of a plurality of operative positions wherein a respective set of contacts is closed to complete an external circuit.

Pivotally mounted on the rotor 12 for pivotal movement about an axis at right angles to the axis about which the rotor 12 moves, is a moulded synthetic resin pivot piece 13 having secured thereto an operating lever 14. The pivot piece 13 includes an integral hollow finger 15 which extends through a hole in the rotor 12 into the cavity 10a defined within the body 10. Disposed ICC centrally in the base of the body 10 is a depression 16 which is surrounded by a generally annular rib 17, and located in the bore of the finger 15 and urged towards the base of the body 11 by a spring 18 is a ball 19.

Positioned within the cavity 10a adjacent the rib 17 is a pair of normally open contacts 21, 22, the contact 21 being supported on a conductive leaf spring 23 which at its end remote from the contact 21 is secured to the body 10, while the contact 22 is mounted on a conductive plate 24 also secured to the body 10. The spring 23 and the plate 24 constitute terminals which are connected in use in an external circuit which is completed by pivoting the pivot piece 13 so that the finger 15 engages and moves the contact 21 into engagement with the contact 22.

When the pivot piece 13 is so positioned with respect to the rotor 12 that the finger 15 is at right angles to the base of the body 10 then the 'ball 19 will be urged by the spring 18 into the depression 16, thereby maintaining the finger 15 in a position spaced from the leaf spring 23, against accidental movement. In order to complete the external circuit controlled by the contacts 21, 22, the lever 14 is moved to pivot the pivot piece 13 so that the finger 15 thereof is moved towards the leaf spring 23. As the finger 15 moves towards the leaf spring 23, the ball 19 is forced to ride out of the depression 16 and over the rib 17. The arrangement is such that when the finger 15 engages and moves the leaf spring 23 so that the contacts 21, 22 are closed, the ball 19 will have cleared the rib 17 and will be urged by the spring 18 into engagernent with the base of the body 10 and the outer surface of the ring 17 remote from the depression 16. Thus the pivot piece 13 is now held in a position wherein the finger 15 closes the contacts 21, 22, since the finger 15 is engaged with the leaf spring 23 and the ball 19 is engaged with the outer surface of the rib 17. In order to open the contacts 21, 22 the lever 14 must be moved in the opposite direction to cause the ball 19 to ride over the rib 17, so that the leaf spring 23 moves the contact 21 out of engagement with the contact 22.

The surface of the finger 15 presented to the leaf spring 23 is curved and the radius of the curved surface is such that when the surface is engaged with the leaf spring 23 and the ball 19 is engaged with the outer surface of the rib 17, then the leaf spring 23 will be maintained, by the finger 15, in a position wherein the contacts 21, 22 are closed throughout the whole range of movement of the rotor 12 relative to the body 10.

The free end (not shown) of the lever 14 can be provided with a push button type switch which controls a further external circuit.

In a practical embodiment of the switch, the switch is secured to the steering column of a road vehicle with the lever 14 extending generally radially outwardly from the column, the axis about which the rotor 12 can move being parallel with the axis of the steering column. In such an embodiment the rotor 12 is movable into any one of three angular positions relative to the body 10. The rotor is used to control contacts associated with the windscreen wipers of the vehicle so that when the rotor 12 is in its first position relative to the body 11 the Windscreen wipers are switched off, and when the rotor is in its second and third positions the wipers are operated at slow and fast speeds respectively. The contacts 21, 22 are connected in the overdrive circuit of the vehicle so that when the contacts 21, 22 are open, the overdrive is disengaged, the lever 14 being moved to close the contacts 21, 22 in order to engage the overdrive, it being appreciated that, as described above, the contacts 21, 22 will be maintained closed until the lever is moved in the opposite direction. The push button switch of the lever 14 can be used to control a windscreen washer pump of the vehicle.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. An electrical switch including a body, a rotor supported on the body for angular movement relative to the body between a plurality of angularly spaced positions, a first set of electrical contacts operable by said angular movement of the rotor, an operating member, means pivotally mounting the operating member on the rotor, for pivotal movement about an axis at right angles to the axis about which the rotor is capable of movement relative to the body, a second set of electrical contacts operable by said pivotal movement of the operating member, and, detent means acting between the body and said operating member, said detent means being capable of maintaining said operating member in either a position wherein said second contacts are open, or in a position wherein said second contacts are closed, irrespective of said angular movements of the rotor.

2. A switch as claimed in claim 1 wherein said detent means comprises a spring loaded member carried by said operating member and a generally circular rib, of conical cross section, on said body, one of said positions of the operating member being defined by engagement of said spring loaded member in the depression defined within the confines of said rib, and the other of said positions being defined by engagement of said spring loaded member with the outer surface of said rib.

3. A switch as claimed in claim 2 wherein said second contacts are urged to a normally open or a normally closed position from which they are'moved by movement of the operating member to said other position, said operating member being urged, When in said other position, by said second contacts, in a direction to engage said spring loaded member with the outer surface of said rib.

References Cited UNITED STATES PATENTS 2,831,081 4/1958 Mason. 3,359,383 12/1967 Cryer.

HERMAN O. I ONES, Primary Examiner US. Cl. X.R. 20061.27

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