Diaphragm pushbutton switch array for keyboards |
|||||||
| 申请号 | US3707609D | 申请日 | 1971-10-27 | 公开(公告)号 | US3707609A | 公开(公告)日 | 1972-12-26 |
| 申请人 | TEXAS INSTRUMENTS INC; | 发明人 | DAPOT MARTIN H; BOULANGER HENRY J; | ||||
| 摘要 | A system employing a keyboard comprises a base mounting an array of key bodies each adapted to reciprocably move to cause actuation of electrical circuits. A diaphragm is employed as an electrical conductor moving into and out of engagement with underlying contacts upon actuation and deactuation of the key body. Bounding problems have been minimized while maintaining tactile feedback by locating a spring member between the key and its respective diaphragm providing increased motion differential and by providing elongate guiding surfaces which eliminate skew movement of the key. Several forms of keys and key mountings are shown embodying the elongated guideway including an elongated hub molded in the bezel plate and receiving a close fitting rod portion of the key, a separate tubular guide and close fitting plunger, and a key having tabs extending laterally therefrom, the tabs slidably received in grooves formed in the base. Another embodiment particularly useful where two or more circuits are to be actuated from the same key employs a second spring to maintain the diaphragm away from the underlying contacts until the key is depressed thereby precluding undesirable back circuits without the use of blocking diodes or the like. | ||||||
| 权利要求 | 1. Keyboard apparatus comprising: a circuit board; a plurality of sets of contacts mounted on the circuit board; a diaphragm retainer plate placed on the circuit board and having a plurality of diaphragm receiving apertures therein, the apertures aligned with respective sets of contacts; an electrically conductive diaphragm located in each diaphragm receiving aperture; a bezel plate placed on the diaphragm retainer plate, the bezel plate having a plurality of spring receiving apertures aligned with the central portion of respective diaphragms; an elongated generally cylindrical plunger guide for and aligned with each diaphragm and contact set, each guide having an axially extending bore and having an outwardly radially extending annular flange on a distal end thereof; a locking plate having a plurality of plunger guide receiving apertures therein, the guides telescopically received in respective plunger guide receiving apertures with the respective flanges locked between the bezel plate and the locking plate; an elongated generally cylindrical plunger having two ends slidably received in each guide bore, a spring seat formed in one end of the plunger; a spring member received in the spring seat of the plunger and extending therefrom through respective spring receiving apertures in the bezel plate and contacting respective diaphragms; and a key head mounted on the other end of respective plungers. 2. Apparatus according to claim 1 in which the ratio of the length of the sliding surfaces of the guide and plunger to the diameter of the plunger is approximately 2 1/2 or greater to 3. Apparatus according to claim 2 in which the clearance between the guide and the plunger is between approximately 0.003 and 0.011 inches. 4. Apparatus according to claim 3 in which the clearance is nominally 0.007 inches. 5. Apparatus according to claim 1 in which the guide bore is provided with at least one axially extending keyway extending from the end having the radial flange, and the plunger has at least one axially extending key which closely fits in the keyway, the junction between the keyway and the key serving to limit outward movement and preclude rotation of the plunger. |
||||||
| 说明书全文 | |||||||
QQ群二维码
意见反馈
意见反馈