Low profile switch

摘要

A low profile switch key has a base which slidingly supports a pushbutton. The pushbutton is slidingly engaged with a plunger body by a lost motion connection. The plunger body carries cams which control the flexing of contactors to make and break conductive connections with adjacent stationary contacts. A coil spring biases the pushbutton upwardly to its rest position. The sliding lost motion between the pushbutton and plunger body allows the pushbutton to slide by itself over an initial pretravel interval when it is pressed. At the end of the pretravel interval, the pushbutton strikes the plunger body and carries the body downward to complete the key stroke. The plunger body resists sliding movement and therefore provides a perceptible pressure point which indicates actuation of the switch. The stationary contacts and associated overlying cams are interlocked when the pushbutton is depressed to provide a relatively low switch profile with respect to the length of the key stroke.