United States Patent Cryer [54] ELECTRICAL SWITCHES [72] Inventor: Edward Cryer, Higham, near Burnley,

England [73] Assignee: Joseph Lucas (Industries) Limited, Birmingham, England 22 Filed: June 10, 1970 21 Appl.No.: 45,001

[30] Foreign Application Priority Data June 17, 1969 Great Britain ..30,534/69 [52] U.S. Cl ..200/6 BB, 200/67 G [5 1] Int. Cl. ..HOlh 13/28 [58] Field oiSearch ..200/139 A, 688, 6C, 68A

[56] References Cited UNITED STATES PATENTS 3,305,630 2/1967 Duffield et al ..,...200/67 F 3,322,914 SH 967 Puccini ...200/67 F 2,678,416 5/1954 Shewmon ..200/6 C [451 June 13, 1972 FOREIGN PATENTS OR APPLICATIONS 489,713 6/1954 ltaly ..200/68 Primary Eraminer-Dzivid Smith, Jr. Attorney-Holman & Stern [57] ABSTRACT An electrical switch includes a body, a conductive support member carried by the body, a pair of electrically interconnecting conductive leaf springs carried by said support member and extending in opposite directions therefrom and fixed contacts carried by the body and engageable by the leaf spring. An operating member is pivotally mounted on the body and engageable with the leaf spring to move the leaf spring relative to the fixed contacts, and the switch has a first stable position in which a plunger holds one of the leaf springs stressed, a second stable position, reached by moving the operating member in one angular direction, in which the plunger moves out of engagement with the leaf spring so that the leaf spring is unstressed, and a third unstable position reached by moving the operating member in the opposite angular direction in which the leaf spring is again unstressed.

1 Claim, 3 Drawing Figures PATENTEnJumlsn 3,670,115

SHEETBUF 2 INVENTOR AfidRNEYs ELECTRICAL SWITCHES This invention relates to electrical switches.

A switch according to the invention includes a body, a conductive support member carried by the body, a pair of electrically interconnected conductive leaf springs carried by said support member and extending in opposite directions therefrom, fixed contacts carried by the body and engageable by said leaf springs, and an operating member pivotally mounted on the body and engageable with said leaf springs to move said leaf springs relative to said fixed contacts.

In another aspect, a switch according to the invention comprises a body, an electrically conductive leaf spring connected to one terminal on the body and movable from a first position which the leaf spring assumes under its own resilience to a position in which the leaf spring is stressed, the leaf spring serving in one of its positions to complete a circuit between said one terminal and a further terminal on the body, and an operating member pivotally mounted on porating a plunger which is resiliently urged towards the leaf spring, the switch having a first stable position in which the plunger holds the leaf spring stressed, a second stable position,

- reached by moving the operating member in one angular direction, in which the plunger moves out of engagement with the leaf spring so that the leaf spring assumes said first position, the switch having athird, unstable position, reached by moving the operating member in the opposite angular direction from the first stable position, movement of the operating member in said opposite angular directioncausing the plunger to move up a ramp surface on the body so that the plunger is disengaged from the leaf spring, which assumes said first position, the operating member returning to said first stable position when it is released under the action of the resilient means acting on the plunger.

An example of the invention is illustrated in the accompanying drawings, in which:

FIGS. 1 and 2 respectively are diagrammatic sectional plan and side views of an electrical switch; and

FIG. 3 is an enlarged view similar to FIG. 1 but with the switch in a different position.

Referring to the drawing the switch includes a hollow moulded synthetic resin body having a base 11, side walls and'an end wall 12. Extending upwardly from the base 11 is a pin 9 serving to support a rotor 8 for angular movement. The rotor 8 has an operating lever 7 secured thereto, and the hollow body is closed by a plate 6 through which the rotor extends. Integrally formed with the rotor 8 is a hollow spigot 13 which extends towards the wall 12. Slidably mounted in the the body and incorspigot 13 is an insulating plunger 14 which is urged by a spring 5, housed within the spigot 13, towards the wall 12. Mounted on the inner surface of the wall 12 is a U-shaped conductive support member 15 which is electrically connected to a blade terminal 20 on the exterior of the body. The free ends of the limbs of the support member 15 are formed with slots and engaged with the support member 15 is a conductive spring strip 17. The strip 17 is engaged in the slots and the edges of the slots are deformed to grip the strip 17 and so retain it in position. Between the limbs of the member 15 the strip 17 is bent to define a V-shaped portion 18 with its apex adjacent the wall 12, the end portions of the strip 17 extending from the limbs of the member 15 in opposite directions to define a pair of conductive leaf springs 19, 21. At its free end the leaf spring 19 carries a downwardly directed contact 22, while the free end of the leaf spring 21 carries an upwardly directed contact 23 and a downwardly presented contact 24. Secured to the body immediately above the free end of the leaf springl9 is a fixed contact 25 which is engaged by the contact 22 in the rest position of the leaf spring 19. Adjacent the free end of the leaf spring 21, the body carries a pair of fixed contacts 26, 27 which are spaced apart'in a vertical direction, the contact 26 being engaged by the contact 23 in the rest position of the leaf spring 21, and the contact 27 being engageable by the contact 24 upon flexure of the leaf spring 21 towards the wall 12. Moreover, adjacent the strip 26 the body is formed with an inwardly directed flange 28 which presents a ramp surface 29 to the lunger 14.

e contacts 25, 26, 27 are electrically connected to respective external terminals of the switch, and the operation of the switch is as follows. In the ofi position shown in FIG. 3, the plunger 14 rests in a stable position at the bottom of the ramp surface 29, with the contact 24 engaging the contact 27 and the contact 22 engaging the contact 25. Clockwise movement from this position moves the operating member to a position seen in FIG. 1 in which the spigot 13 extends generally at right angles to the wall 12, and the plunger 14 is engaged in the V-shaped portion 18 of the strip 17. In this position the contact 23 is engaged with the contact 26.

- Further movement of the operating member relative to the body in a clockwise direction causes the plunger 14 to ride out of the portion 18 of the strip 17 and onto the leaf spring 19, thereby flexing the leaf spring 19 towards the base 12 and disengaging the contacts 22 and 25. The contacts 23, 26 remain engaged. These three positions are stable, but by pivoting the operating member in a counter clockwise direction from the position shown in FIG. 3, the plunger 14 is caused to engage the ramp surface 29, and rides up the ramp surface as permitted by compression of the spring 5, thereby permitting the leaf spring 21 to return to its rest position wherein the contact 23 engages the contact 26, and the switch is in the same electrical position as in FIG. 2. When the operating member is released while the plunger 14 is engaged with the ramp surface 29, the various parts return to the position shown in FIG. 3.

In one example of the use of the switch described above the switch is utilized to control the operation of a two speed windscreen wiper motor. In the off position shown in FIG. 3, the motor is short-circuited as soon as the wipers reach their parking position. In the first operative position shown in FIG. 2 the motor is operated at its slow speed, and in the second operative position the motor is operated at its fast speed. One or more wipes of the screen are readily attainable by moving the switch to its unstable operative position against the action of the spring 5. Where the motor has a parking switch, momentary operation of the switch in this way will give a single wipe.

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 conductive support member carried by the body, a pair of electrically interconnected conductive leaf springs carried by said support member and extending in opposite directions therefrom, fixed contacts carried by the body and engageable by said leaf springs, an operating member pivotally mounted on the body and incorporating a spring loaded plunger engageable with said leaf springs to move said leaf springs relative to said fixed contacts, said leaf springs being integral with one another, and said switch incorporating detent means defining a first switch position in which said plunger engages a V-shaped portion defined by said leaf springs, neither leaf spring being stressed in this first switch position, the operating member being movable in one angular direction from said first switch position to a second stable switch position in which one of the leaf springs is stressed, and said operating member being movable in the opposite angular direction from said first switch position to a third switch position in which said other leaf spring is stressed, said switch incorporating a ramp surface which is engaged by said plunger when said switch is moved beyond said third switch position, said ramp surface moving said plunger out of engagement with the leaf springs to define a fourth unstable switch position.