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:
May. 04, 1976
Filed:
Mar. 11, 1974
Applicant:
Inventors:
Ralph D Brower, Longmont, CO (US);
Neil L Robinson, Boulder, CO (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; E05F / ;
U.S. Cl.
CPC ...
360122 ; 5128 / ;
Abstract
A head is moved toward and rotated against an abrasive while its resistance is monitored by a four-lead bridge. Prior to final manufacture, the head includes a highly conductive segment which surrounds the active head element on three sides and is electrically connected to it at one point. The segment is ground away during manufacture. Two leads from the head are connected to two slip rings, and each slip ring has two pairs of brushes, each wire from the bridge going to a different brush pair. Head movement toward the abrasive is terminated when a predetermined head resistance is detected by the bridge.