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:
Jun. 11, 1991
Filed:
Sep. 26, 1990
Paul B Campbell, Roanoke, VA (US);
Ingersoll-Rand Company, Woodcliff Lake, NJ (US);
Abstract
A variable frequency control for a hydraulic percussion actuator includes a piston bore and a valve bore. A piston is axially disposed within the piston bore, while a valve is axially disposed within the valve bore. A first piston biasing member biases the piston in a first direction while a second piston biasing member, which overcomes the bias of the first piston biasing member to move the piston in a second direction. A first valve biasing pin biases the valve in a third direction while a second valve biasing pin overcomes the bias of the first valve biasing pin to move the valve in a fourth direction. A hydraulic valve actuator displaces the second valve biasing pin when the piston is extended in the second direction, and a piston actuator activates the second piston biasing pin when the valve is extended in the fourth direction. A valve response member controls the time required for the valve to be displaced in said fourth direction upon actuation of said valve actuating member.