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. 04, 1989
Filed:
Jun. 02, 1988
James C Liu, Fu-Sheng Tsun, Hsin-Shen Hsiang, Taichung Hsien, TW;
Other;
Abstract
A door-closer has an air cylinder in which a piston rod and a piston body are provided to define first and second sealed chambers. The piston body is sleeved movably on the piston rod and has a tapered bore which is communicated with the second chamber. A closable passage is formed through the piston and communicated with the first and second chambers. A spring-biased seal is disposed in the second chamber and biased to close the closable passage. A regulatable passage is formed through the piston body and communicated with the tapered bore and the first chamber. The piston rod has a shoulder which is movable axially within the tapered bore by rotating the cylinder relative to the piston rod for regulating the air flow between the first and second chambers through the regulatable passage. The spring-biased seal is movable to open the closable passage when the piston body moves in response to the opening of the door. When the door is opened, compressed air flows from the first chamber to the second chamber through the regulatable passage and the closable passage. When the opened door is released, compressed air flows from the second chamber to the first chamber through the regulatable passage.