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:
Sep. 14, 1993
Filed:
Mar. 09, 1992
James A O'Brien, II, Burbank, CA (US);
Thomas Industries, Inc., Los Angeles, CA (US);
Abstract
A device for closing swinging doors of the type utilizing a rotating member to compress a spring during door opening to store energy in the spring to effect a closing of the door is provided with a driving connection to a d.c motor/generator effective to cause rotation of the motor during a closing movement of the door. The motor/generator acts as a generator during the closing with the generated electrical energy fed back to the motor/generator to retard rotation of the rotor, providing a brake on the closing movement of the door. The feedback circuitry includes a switch disabling or diminishing the braking during the final degrees of closing movement as well as a variable setting device allowing control of braking force.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile