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. 03, 1984
Filed:
Nov. 23, 1981
David F Dodgen, Boca Raton, FL (US);
Ludwig R Siegl, Highland Beach, FL (US);
International Business Machines, Armonk, NY (US);
Abstract
A real time tachometer is realized in an electromechanical device having a moving member, for example a disk, of nonmagnetic electrically conductive material driven by a suitable moving device, for example a rotating shaft, the velocity of which is to be determined. An assembly of at least one permanent magnet and at least one Hall effect device is arranged for inducing eddy currents in the moving member or rotating disk and measuring them for indicating the relative velocity. The placement and electric interconnection of the Hall effect devices measure the magnetic field provided by the magnet and in an alternate embodiment incorporate compensation for runout and adverse deflection with a rotating disk.