Ganged Push-Button Switch

The present invention relates to a ganged push-button switch which is particularly suited for such applications as automobiles and motorcycles.

According to the conventional ganged push-button switches as have been disclosed in, for example, U.S. Pat. Nos. 3,927,283, 3, 889,075 and 3,836,736, a plurality of push-button switches are mounted in parallel on a frame, and respective portions of an interlocking plate act upon the cams portions are provided for each of the plurality of push-button switches, so that when any one of the push-button switches is depressed, another push-button switch which had been locked is unlocked.

With such ganged push-button switches having only one interlocking plate, however, a push-button switch which should be kept locked is often unlocked if subjected to a strong impact. Therefore, the conventional ganged push-button switches leave much room for improvement when they are to be used in automobiles and motorcycles which are often subject to vibration.

The object of the present invention therefore is to provide a ganged push-button switch which will not operate erroneously even when subjected to vibration or impact.

Another object of the present invention is to provide a ganged push-button switch having two sets of interlocking mechanisms.

Further objects and advantages of the invention will become apparent from the description of the invention in conjunction with the accompanying drawings.

FIG. 1 is a side view of a ganged push-button switch according to the present invention;

FIG. 2 is a perspective view when the ganged push-button switch of the present invention is disassembled;

FIG. 3 is a perspective view illustrating, on an enlarged scale, cam portions employed for the ganged push-button switch of the present invention;

FIG. 4a is an upper view for illustrating, partly in cross section, the operation of the ganged push-button switch of the present invention, in which none of the push-button switches have been depressed; and

FIG. 4b is an upper view illustrating, partly in cross section, the state when one push-button switch is depressed.

The invention is illustrated below with reference to FIGS. 1 to 4.

Referring to FIG. 1, a push-button switch S consists of a casing 2 on which are studded fixed terminals 1, an operation rod 3, a return spring 4, a first interlocking plate 5, a second interlocking plate 8, and a metallic frame 7 for holding the push-button switches together. FIG. 2 illustrates the ganged push-button switch in a disassembled manner, from which the shapes of the first interlocking plate 5, a spring 6 associated with the first interlocking plate, the second interlocking plate 8, and a spring 9 related to the second interlocking plate, can be understood. FIG. 2 further clarifies relations in positions of first cam portions 3a to 3c and second cam portions 3d to 3f formed in the operation rod 3.

As will be evident from FIG. 3, the first cam portions 3a to 3c are formed in one side of the operation rod 3, which side is urged by the first interlocking plate 5 via the spring 6. The second cam portions 3d to 3f are formed in the upper surface of the operation rod 3 at right angles with the side surface, which upper surface is urged by the second interlocking plate 8 via the spring 9.

The ganged operation of the ganged push-button switch of the present invention is described below with reference to FIGS. 4a and 4b. First, if a push rod 3 is depressed, a projecting portion 3b on the first cam portion 3a forces the first interlocking cam plate 5 against the resilient force of the spring 6 and, at the same time, a ridge portion 3e on the second cam portion 3d forces the second interlocking cam plate 8 against the resilient force of the spring 9. As the operation rod 3 is moved further, an engaging portion 5a on the first interlocking plate 5 falls into an engaging recess 3c after passing over the projecting portion 3b of the first cam portion 3a, and an engaging portion 8a on the second interlocking plate 8 falls into an engaging valley 3f after passing over the ridge portion 3e of the second cam portion 3d. Thereafter, when the depressing force is discontinued, the first and second cam portions 3a, 3d of the operation rod 3 are engaged with the engaging portions 5a, 8a of the first and second interlocking plates 5, 8, and the operation rod 3 is locked by the two interlocking plates 5, 8.

Then, when another operation rod 3 is depressed, the first and second cam portions 3a, 3d of that operation rod force the first and second interlocking plates 5, 8 into their non-engaging position. The depressed operation rod is then locked owing to the same operation mentioned in the foregoing. Further, when this operation rod 3 is depressed causing the interlocking plates 5, 8 to be moved against the resilience of the respective springs, the operation rod 3 which had been depressed is unlocked from the interlocking plates 5, 8 and is returned to the initial state being urged by the return spring. Thus, the ganged operation of a plurality of operation rods 3 is effected.

In short, according to the present invention, the first and second cam portions 3a, 3d are formed in each of the operation rods 3 at positions at right angles to each other, wherein the first cam portion 3a is detachably engaged with the first interlocking plate 5 and the second cam portion 3d is detachably engaged with the second interlocking plate 8, so that each operation rod 3 is locked by the two interlocking plates 5, 8. Accordingly, the operation rod 3 can be reliably locked and is not unexpectedly unlocked by vibration or impact. Consequently, the ganged push-button switch of the present invention is suited for such applications as automobiles and motorcycles.