Abstract: A keyboard switch having a membrane contact point sheet and a push button key for pressing down a contact point portion of the membrane contact point sheet, further includes a housing including a base portion and a casing portion, a key top which is slidably supported in the casting portion and has a contact point pressing portion projecting toward the base portion in an area extending outside a periphery of the casing portion, and a biasing member for biasing the key top toward a home position. The membrane contact point sheet is disposed on the base portion of the housing so that the contact point portion is confronted with the contact point pressing portion, and is formed in a three-layered structure, including an upper contact point sheet, a spacer, and a lower contact point sheet. The contact point portion has a window hole provided in the spacer.

Abstract: A push-button switch comprises a fixed electrode; a movable electrode disposed opposite to the fixed electrode; a key housing having a tubular spring retainer, and an annular guide wall surrounding the tubular spring retainer and having a stopping flange, a coil spring received in the tubular spring retainer, and a key for operating the movable electrode through the coil spring. The coil spring has a large coil section, a middle extension coil section, and a small compression coil section having a projecting part. The tubular spring retainer is provided with a protrusion on the inner circumference thereof. When the key is depressed to close the switch, the projecting part of the coil spring is forced to move down over the protrusion in a snap motion, and the projecting part is forced to move up over the protrusion by the contractive force of the middle extension coil section and the recoiling force of the small compression coil section of the coil spring when the key is released.