The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 1995
Filed:
Dec. 17, 1993
Kazunori Yamada, Tokyo, JP;
SMK Co., Ltd., Tokyo, JP;
Abstract
A key stem of a keyboard switch includes an outer slide and an inner slide. When a key top is struck, the outer slide slides inside of an outer guide, and the inner slide slides inside an inner guide. A first moment point is developed between the outer slide and the outer guide, while a second moment point is developed between the inner slide and the inner guide. A taper at the bottom of the outer slide prevents the second moment point being developed in that location. The reduced horizontal distance between the two moment points helps prevent binding of the key when an actuating force is applied off the axis of the key top. A relationship is disclosed for avoiding sticking or binding in which the horizontal distance between the two moment points, times a coefficient of friction, is less than the vertical distance between the planes of the two moment points.