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:
Apr. 24, 1990
Filed:
Oct. 25, 1988
Applicant:
Inventor:
Norman G Gratke, Elm Grove, WI (US);
Assignee:
W. H. Brady Co., Milwaukee, WI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03M / ;
U.S. Cl.
CPC ...
341 22 ; 341 33 ; 200 / ; 200600 ; 200292 ;
Abstract
A decodable alphanumeric membrane switchcore (12, 12a, 12b,100) of at least 36 key cells (55,122) including spaced circuits (16,17;105,115) having row and column traces (20-34, 40-47,51;106,116) and key cell elements (37,38,49;80;107,117) printed with ink having a resisitivity of at least about 10 ohms per square per 0.001' of ink thickness and having at least one path defined by a row trace, column trace and a key cell that has a resistance greater than 10,000 ohms.