Matsushita Electric Works, Ltd.

Yasunari Takedomi

Ryoji Ito

Takao Morimoto

Hidetaka Mori

A see-saw switch capable of closing the contacts at a high initial contact pressure. The switch includes a housing provided with a fixed contact, and a lever provided with a movable contact at one longitudinal end thereof. The lever is pivotally supported to the housing for pivotal movement about a pivot axis between a contact closing position and a contact opening position. A plunger is slidably supported to the housing for linear movement along an axial direction of the plunger, and has an actuator which is held in slidable contact with said lever for translating the linear movement of the plunger into the pivotal movement of the lever so that, when the plunger moves in a forward direction, the actuator causes the lever to pivot about the pivot axis into the closed position. A restrictor is provided to keep the lever engaged with the plunger in order to restrict the lever from pivoting from the open position to the closed position until the actuator proceeds in the forward direction past a critical point which is offset from the pivot axis by a certain distance towards the movable contact along the lever. Thus, the lever operates to close the contacts only after the actuator past the critical point where it applies a sufficient force to the lever so as to impart the substantial initial contacting pressure between the contacts.

See-saw switch

A miniature pushbutton switch capable of being made compact as well as being given a sufficient contacting pressure for reliable switch operation. The switch comprises a housing with first and second contacts, and an electrically conductive torsion coil spring composed of a coil portion and a pair of first and second arms integrally extending therefrom. The coil spring is assembled in the housing with the first arm constantly engaged electrically with the first contact and with the second contact in engageable relation with the second contact. A pushbutton is supported by the housing to be movable between an inoperative position and an operative position respectively of breaking and making the electrical connection between the second arm and the second contact. The first and second arms extend in opposite directions from the coil portion. The pushbutton is held in direct engagement with the coil portion to displace it when the pushbutton is pushed to the operative position, whereby the second arms is caused to resiliently deform to make or break the electrical connection with the second contact. As the coil portion is displaced by a force applied from the pushbutton, the second arm as well as the first arm are resiliently deformed to thereby develop sufficient contacting pressures even at the beginning of engaging the second arm with the second contact. Consequently, the switch can be easily designed to have sufficient contacting pressures for reliable switch operation, even with the use of the coil spring of reduced axial length.

Miniature pushbutton switch with coil spring contact

A sealed electric switch comprises a molded switch housing and a separately formed cover which fits on the switch housing wiht an annular seal member interposed between mating peripheral surfaces of the switch housing and the cover. An annular seal member is injection-molded from an elastic material on the mating peripheral surface of the switch housing between separable molding dies with the switch housing held therebetween. The annular seal member is integrally formed with an additional segment which extends in a separating direction of the molding dies and joins at its end to the annular seal member so as to reinforce it against a separation force applied thereto at the time of separating the molding dies.

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Hisai, Japan

Yasunari Takedomi