Patent · US Expired

Hydraulic rock drill system

US3995700A · kind A · utility

15Cited by
8References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 14, 1975
Grant dateDec 7, 1976
Priority date
Expiry dateOct 14, 1995

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S173/04
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

In a hydraulic percussion rock drill the operation of the working fluid distributing valve is controlled to effect a variation in percussive blow energy and blow frequency by varying the piston hammer stroke. Actuation of the distributing valve is controlled by a remote controlled hydraulically actuated pressure control valve interposed in a fluid passage which conducts hydraulic fluid from the hammer bore to actuate the distributing valve. Substantially infinite variation of hammer impact blow energy between high and low limits provides for selecting the maximum penetration rate of the drill for any type of rock conditions. The hydraulic rock drill is connected to a source of hydraulic fluid supplied to the drill at substantially constant fluid power by a variable displacement constant power hydraulic pump.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.