Browse Prior Art Database

Low Cost Keyboard Actuator

IP.com Disclosure Number: IPCOM000050490D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 59K

Publishing Venue

IBM

Related People

Dials, EN: AUTHOR [+2]

Abstract

A low cost keyboard actuator includes a single molded plastic part having all keylevers and keybuttons molded thereon, a comb-like leaf spring member located under the keylevers for providing tactile response and key return, and a cam and cam spring member to provide tactile response.

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Low Cost Keyboard Actuator

A low cost keyboard actuator includes a single molded plastic part having all keylevers and keybuttons molded thereon, a comb-like leaf spring member located under the keylevers for providing tactile response and key return, and a cam and cam spring member to provide tactile response.

With reference to Figs. 1-3, a single molded plastic part 11 includes plural keylevers 13 having keybuttons 14 molded thereto. Downward depression of a keybutton 14 causes the plastic keylever 13 to deflect in an area 15 near the grounded cross-member portion 17 of the plastic part 11. A comb-like leaf spring, having spring fingers 19, is attached to the underside of the cross member 17. The individual leaf springs 19 contact corresponding actuator surfaces 21 molded on the underside of each keylever 13. Downward movement of the keylever 13 thus causes its associated spring 19 to deflect downwardly. The spring 19 provides a force resisting the downward key movement. As the keybutton 14 moves downward, end portion 23 of the spring 19 contacts the circuit card 25 located on the frame 27. The circuit card may contain membrane switch actuators or ohmic contacts which are closed by the action of the end portion 23 of the spring 19 thereagainst.

Downward motion of the key stem 13 is also resisted by the cam spring 33 and cam 31 which extends across the width of the keyboard so as to contact the end 35 of each keylever 13 as it moves downward. With reference to Fig. 4, as the keylever 13 moves from its upper position to its lower position,...