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. 16, 1996
Filed:
Aug. 11, 1994
Craig L Lucas, Princeton, IL (US);
Schlage Lock Company, San Francisco, CA (US);
Abstract
A method for making a hydraulic door closer includes the steps of molding material to form an elongated single-piece housing having a longitudinal cylindrical bore extending from a first open end thereof to a closed second end, a transverse intersecting bore, and mounting feet; installing a spring within the cylindrical bore at the closed end of the housing; installing a piston within the cylindrical bore in contact with the spring, the piston having a toothed rack thereon and an opening in each end to permit passage of fluid therethrough; installing a pinion gear in the transverse intersecting bore in meshed engagement with the toothed rack; installing an endplug with a port in the first end of the longitudinal cylindrical bore; and inserting a valve device through the port, for controlling flow of fluid through the piston, and for thereby controlling closing speed of the door. The single-piece housing as well as other components may be molded from metal or polymeric materials. Polymeric materials are preferred for their flexibility, lubricity, and moldability.