Browse Prior Art Database

Membrane Switch Keyboard Assembly

IP.com Disclosure Number: IPCOM000046075D
Original Publication Date: 1983-May-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Williams, GT: AUTHOR

Abstract

A keyboard assembly including key actuators is used in conjunction with an array of membrane switches to produce an electrical output indicating key actuation. The keyboard assembly is constructed with spacer members to eliminate pressure points on the membrane switch array.

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Membrane Switch Keyboard Assembly

A keyboard assembly including key actuators is used in conjunction with an array of membrane switches to produce an electrical output indicating key actuation. The keyboard assembly is constructed with spacer members to eliminate pressure points on the membrane switch array.

A three-layer membrane switch array 13 includes a lower layer 15 and an upper layer 17 having contacts thereon and a spacer layer 19 having apertures therein aligned with the contacts so that a downward force on layer 17 in an area approximate one of the apertures in the layer 19 effects switch closure. Since numerous switch points exist in a keyboard, it is important that the structure supporting the membrane switch array 13 does not load the membrane switch array 13 with pressure.

The membrane switch array 13 is supported on a curved base plate 21. The key actuators 22 are supported on a frame 23 having plural key chimneys 25 formed therein. The frame 23 and plate 21 are joined together by a stud 27 which extends downwardly through an aperture 29 in the plate 21. Stud 27 is thereafter hot upset against the plate 21. The frame 23 contains channel guides 31 which are shaped to contain the actuators 22. Boss member 35 is attached to the stud 27 to prevent the guides 31 from contacting the membrane switch array
13. The membrane switch array 13 has a hole 29 cut therein through which the stud 27 and the boss member 35 extend. Thus, the space between the frame 23...