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. 23, 1991
Filed:
Aug. 25, 1989
Jeffrey W Hamner, Allen, TX (US);
Ingersoll-Rand Company, Woodcliff Lake, NJ (US);
Abstract
A drill feed control system for controlling the force exerted on a drill string having substantial weight. A feed cylinder, which has a first end and a second end, is connected to the drill string. Fluid is pumped from a reservoir to displace the feed cylinder. A first conduit is connected to the first end while a second conduit is attached to the second end. A variable displacement pump displaces fluid from the reservoir, within the first conduit, to the first end of the feed cylinder. A feed pressure control regulates the pressure of the variable displacement pump. An overcenter valve, which is connected to the second conduit, restricts the fluid exiting the second conduit. A relief valve controls the flow of fluid to a pilot conduit which extends between the first conduit and the overcenter valve. An orifice or check valve to release the pressure is connected to the pilot conduit such the the pressure in the pressure conduit will respond to a pressure increase or decrease in the first conduit. The pressure in the pilot conduit and the second conduit interact to open the overcenter valve.