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:
Aug. 21, 1990
Filed:
Oct. 21, 1988
Robert A Olsen, Janesville, WI (US);
Dana Corporation, Toledo, OH (US);
Abstract
A soft start electromagnetic coupling has a driven member and a driving member that are coupled together in response to a magnetic flux produced by a direct current flow through a winding on the clutch. When the members are coupled by an electromagnetic flux, they may slip relative to reach other during starting, when the load on the coupling changes or when the accessory driven by the coupling freezes or becomes jammed. Relative slippage of the members produces an alternating current component in the direct current flow that is detected to indicate the slippage. The presence of an alternating current component can be sensed through a rectifier or frequency filter. Preferably, the presence of a persistent alternating current component causes a switch to open, interrupting the flow of direct current to the coupling. Interruption of the current flow disengages the coupling and prevents damage to other accessories that may be driven by the same endless belt and to the belt that engages the driven member of the coupling.