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:
Dec. 03, 1991
Filed:
Feb. 08, 1991
Rand H Hulsing, II, Redmond, WA (US);
Sundstrad Data Control, Inc., Redmond, WA (US);
Abstract
A torque motor for rotatably driving a rate sensor (10, 100) which includes a permanent magnet (30) that is magnetically coupled to an upper rotor (18, 106) and a lower rotor (44, 110). At three sites, the upper rotor includes an upper tab (60), which is centered between two electromagnetic coils (56, 58). Similarly, at each site, the lower rotor includes two lower tabs (62) that extend adjacent opposite faces of the electromagnetic coils. With no electrical current flowing through the electromagnetic coils, flexures (46) that connect the upper and lower rotors to a base (12) provide a spring bias force sufficient to maintain the upper tab centered in a slot (66) and thus, equidistant between each of the two lower tabs. As the electric current flows through the electromagnetic coils, distribution of the magnetic flux produced by the permanent magnet changes so that the upper tab is attracted toward one of the electromagnetic coils and repelled from the other. At the same time, the lower tabs are respectively repelled from and attracted toward the opposite faces of the electromagnetic coils. Thus, the upper and lower rotors dither back and forth in opposite directions about a central axis of rotation (78) each time the electromagnetic coil polarity changes because of a change in the direction of electrical current flow through the electromagnetic coils.