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:
Jul. 28, 1992
Filed:
Jan. 28, 1991
George D Larson, Minneapolis, MN (US);
Reell Precision Manufacturing, St. Paul, MN (US);
Abstract
A self-braking electromagnetic wrap spring clutch having a wrap spring control ring and a brake control armature plate at separate locations within a common magnetic circuit. The self-braking electromagnetic clutch includes: a shaft, a driving hub rotatable on said shaft and carrying a wrap spring and a control ring, a driven hub attached to said shaft, a shoulder assembly directly axially adjacent to said control ring extending radially from and rotatable with the driven hub and having ferromagnetic radially inner and outer annular segments separated by a binder having a sufficiently low magnetic permeance in relation to the inner and outer segments to create a magnetic permeance discontinuity therebetween, an armature plate adjacent to the shoulder assembly and being axially slidable toward and a way from the shoulder assembly, a non-rotatable friction plate axially adjacent to the armature plate, biasing means for biasing the armature plate into frictional contact with the friction plate, and non-rotatable magnetic circuit body means for directing magnetic flux simultaneously between the control ring and the shoulder assembly and between the armature plate and the shoulder assembly.