Control keyboard switch with cantilevered contact and diode matrix array |
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| 申请号 | US3731015D | 申请日 | 1971-05-18 | 公开(公告)号 | US3731015A | 公开(公告)日 | 1973-05-01 |
| 申请人 | UNIVERSAL TECHNOLOGY; | 发明人 | BRADY J; | ||||
| 摘要 | A low profile keyboard unit including an etched circuit board and a plurality of keyboard switches mounted on one surface thereof. Individual switches include housings configured to carry in self-contained fashion up to ten diodes plus a resistor, the leads from these elements being passed through holes in the board and flow soldered at the back side of the board. | ||||||
| 权利要求 | 1. A keyboard unit comprising in combination: a circuit board including a plurality of generally parallel conductive tracks at least one of which is connectable to a source of input potential, a plurality of conductively plated holes formed through said board and connected to said tracks, and a series of output terminals connected to said tracks; a plurality of keyboard switches mounted on said board over said holes, each of said switches including an individual housing, a fixed conductive plate therein, a movable contact, actuating means for moving said movable contact into engagement with said fixed conductive plate, and space for carrying similarly shaped switching diodes; and a plurality of diodes, at least one diode being mounted in each keyboard switch, each diode having a pair of leads one of which protrudes from said housing, passes directly through a hole in the circuit board and is joined to the hole boundary to form an electrical connection to one of said conductive tracks and the other of which is connected to the fixed conductive plate of the keyboard switch in which it is mounted, whereby signals may be established at the output terminals upon operation of the actuating means in accordance with the arrangement and number of diodes in said keyboard switch. 2. Apparatus in accordance with claim 1 wherein said conductive tracks and the overlying switches are arranged in a plurality of parallel rows. 3. Apparatus in accordance with claim 1, wherein said conductive tracks are present on both sides of said board, and at least some of the tracks on opposite sides of said board are electrically connected to one another through said conductively surfaced holes. 4. Apparatus in accordance with claim 3 wherein at least 10 of said tracks underlie each switch, whereby direct connection to at least an equal number of said switching diodes is enabled. 5. Apparatus in accordance with claim 4 wherein each diode in a keyboard switch is connected to a different underlying track. 6. Apparatus in accordance with claim 1 wherein: the movable contact is supported in cantilevered fashion in its housing, said movable contact being positioned approximately in parallel spaced relationship to said fixed conductive plate; and the actuating means comprises plunger means movable into said housing in a direction transverse to the plane of said movable contact, said plunger meanS being adapted upon said movement to bear upon said movable contact and displace the cantilevered portion thereof into contact with said fixed conductive plate to close the keyboard switch. 7. Apparatus in accordance with claim 6 wherein said movable contact comprises a generally flattened member having a base portion and a pair of branch portions extending from said base portion and in turn branching into multiple contact fingers, said movable contact being supported in said housing at said base portion, said branch portions being cantilevered over said fixed conductive plate. 8. Apparatus in accordance with claim 7 wherein the base portion, the branch portions and contact fingers surround and define an opening in said movable contact. 9. Apparatus in accordance with claim 8 wherein said plunger means bears on said contact fingers to displace them into contact with said fixed conductive plate. 10. Apparatus in accordance with claim 2 wherein the base portion, the branch portions and the finger portions of said movable contact surround and define an opening in said contact, an opening being present in said fixed conductive plate, and a plunger support passage being present in said housing, and wherein said plunger includes a foot portion adapted to pass through said openings and into said passage of said housing and a laterally extending pad portion which presses against said fingers of said movable contact to effect said displacement thereof as said pad contacts said movable contact. 11. Apparatus in accordance with claim 10, wherein said foot is of generally cylindrical shape, said depressed portion thereon comprising a flat on said cylinder, the said tactile ball resting against the shoulder defined between said flat and the remaining portion of said cylinder when said plunger is in an undepressed condition. 12. Apparatus in accordance with claim 10, wherein said plunger support passage includes a keyway extending longitudinally therein and said plunger foot includes a longitudinal slot for engaging said keyway and steadying the lateral movement of said plunger, whereby to reduce wobble at said key top. 13. Apparatus in accordance with claim 6, further including a key top interconnected with said plunger means to effect said displacement thereof upon operator pressure. 14. Apparatus in accordance with claim 7, further including a return spring compressible by said displacement of said plunger means to provide a restoring force for returning said plunger to its original position. 15. Apparatus in accordance with claim 6, wherein said housing is formed with a transverse platform for supporting said contact plate, said platform being stepped upwardly at an end thereof to define a narrow support ledge for the base portion of said contact leaf. 16. Apparatus in accordance with claim 6 wherein the source of input potential is connected to the movable contact. 17. Apparatus in accordance with claim 6 wherein: said movable contact comprises a member having a base portion, a branch portion extending from said base portion, and multiple contact fingers connected to said branch portion and cantilevered over said fixed conductive plate; and said plunger means bears on said contact fingers to displace them into contact with said fixed conductive plate. 18. Apparatus in accordance with claim 6, wherein said plunger means carries a depressed portion on a face thereof parallel to the direction of said displacement, and wherein said switch further includes a tactile ball and a tactile spring nested in said housing for biasing said ball against said plunger face, said spring and ball being nested at a position such that when the plunger is in an undepressed position the tactile ball rests in said depressed portion and thereby provides a resistive force to displacement of said plunger, sufficient force upon said plunger acting to move said plunger and displace said ball outwardly from said depressed portion whereby to suddenly reduce the said resistivE force and provide tactile indication to the operator of movement of said plunger. |
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