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. 24, 2012
Filed:
Mar. 24, 2010
Karl Harvey Lundahl, Stanchfield, MN (US);
Karl Harvey Lundahl, Stanchfield, MN (US);
Industrial Spring Company, Coon Rapids, MN (US);
Abstract
A spring assembly is provided for an upward acting door that travels on a travel path while opening. The assembly includes a shaft, a torsion spring and a second spring. The torsion spring is connected to the shaft and provides a lifting force for the door throughout the travel path. The second spring is connected to the shaft and provides a lifting force for the door during only a portion of the travel path. In another aspect, a spring assembly is provided for an upward acting door that travels on a travel path while closing. The torsion spring is connected to the shaft and provides a weight supporting force for the door throughout the travel path. The second spring is connected to the shaft and provides a weight supporting force for the door during only a portion of the travel path.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile