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Momentary Contact Latch Down Switch

IP.com Disclosure Number: IPCOM000049599D
Original Publication Date: 1982-Jun-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Krimm, DL: AUTHOR [+3]

Abstract

A momentary contact latch down switch is utilized allowing the shift lock keybutton of a membrane keyboard to remain locked down while removing pressure from the membrane contact once it has made initial contact. The pressure removal prevents the membrane member from having the tendency to creep under the constant stress imposed by the locked down keybutton actuator.

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Momentary Contact Latch Down Switch

A momentary contact latch down switch is utilized allowing the shift lock keybutton of a membrane keyboard to remain locked down while removing pressure from the membrane contact once it has made initial contact. The pressure removal prevents the membrane member from having the tendency to creep under the constant stress imposed by the locked down keybutton actuator.

With reference to Fig. 1, the depression of keybutton 11 compresses spring 13 causing spring 13 to press downward on actuator 15 and membrane 17, closing contacts 19 as depicted in Fig. 2. Further depression of keybutton 11 causes surface 2l of keybutton 11 to press on the periphery of washer 23, deflecting the plates 24 (Fig. 4) of washer 23 about the pivot circle 25 as depicted in Fig. 3. The pivoting of the washer 23 lifts actuator 15 from membrane 17, allowing contacts 19 to open. An external latch such as a ballpoint pen actuator latch (not shown) latches keybutton 11, holding it in its depressed position. Release of this latch mechanism allows the keybutton to return to its initial position and momentarily effects reclosing of contacts 19.

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