Browse Prior Art Database

Leaf Spring Module

IP.com Disclosure Number: IPCOM000050145D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 3 page(s) / 46K

Publishing Venue

IBM

Related People

Olson, GD: AUTHOR

Abstract

A finger depression force on a keybutton to a pivot plate in a key module may be accomplished by a number of different techniques. The use of a leaf spring is illustrated in the figures.

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Leaf Spring Module

A finger depression force on a keybutton to a pivot plate in a key module may be accomplished by a number of different techniques. The use of a leaf spring is illustrated in the figures.

The leaf spring 10 may be molded as a part of the keybutton 12 and stem 14 as a single molding operation, leaving a thin strip of plastic material depending from the keybutton stem 14. This arrangement is illustrated most clearly in Fig.
1. When this arrangement is implemented into a keyboard using a pad card and pivot plate, similar in concept to the keyboard described in U.S. Patent 4,118,611, the spring 10 is deflected from its undeformed position to form a buckling bend, as illustrated in Fig. 2.

The end of the spring 10 engages stop 16 formed on the end of pivot plate
18. Thus, the bend of spring 10 is maintained once the keybutton stem 14, spring 10 and pivot plate 18 are assembled within the chimney 20 of the frame. Chimney 20 provides a guide and support for stem 14. Spring 10 is configured to have a length sufficient to engage the stop 16 and yet not fully engage the radius surface 22 of pivot plate 18 in the raised keybutton position. This tends to exert force from the end of spring 10 downwardly against the pivot plate 18 in the region of stop 16, thus insuring that the pivot plate is maintained in a raised condition with respect to the pad card 24.

The pivot plate 18 is provided with a fulcrum point 26 which engages the pad card at all times and acts as a defined pivot. When the keybutton 12 and stem 14 are depressed under the influence of thicker force, spring 10 will further deform as it is buckled and, as it does so, will cause the spring to conform to the radius 22 of pivot plate 18. As the spring fully engages the radius surface 22, the force point between...