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:
Oct. 26, 1982
Filed:
Jun. 23, 1980
Esa Karru, Tampere, FI;
Pekka Salmi, Tampere, FI;
Hannu Paasonen, Nokia, FI;
Aimo Helin, Tampere, FI;
Oy Tampella AB, , FI;
Abstract
A hydraulic drilling apparatus, especially a rock drill comprising a body, a cylinder in the body and a percussion piston reciprocating in the cylinder. A tool is connected to the body and a motor is provided for rotating the tool. A control valve is also provided for the percussion power. A control valve is also provided for regulating the motor speed. Both of these control valves are operated independently by one lever. A hydraulically operated flushing valve is also provided. A hydraulic pump and hydraulic channels coact to form a percussion circuit and a rotation circuit is parallelly coupled with the percussion circuit in relation to the hydraulic pump. A flushing valve circuit is controlled by the percussion circuit and a circuit for the free circulation of the hydraulic pump which is parallelly coupled with the percussion circuit in relation to the hydraulic pump. The circuits are connected to the hydraulic pump. The control valves are disposed in the body of the percussion apparatus with one of these valves being in the rotation circuit for controlling the flow rate which valve is a pressure-compensated flow control valve with a throttling control.