Hydraulically operated percussion mechanism

• Main Authors: BARTELS, ROBERT-JAN, PIOTROWSKI, HANS-DIETER
• Format: Patent
• Language: English; French; German
• Published: 11.10.1995
• Edition: 5
• Subjects: BORING; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; HAND TOOLS; MACHINE TOOLS; MANIPULATORS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PERCUSSIVE TOOLS; PERFORMING OPERATIONS; PORTABLE POWER-DRIVEN TOOLS; TRANSPORTING; TURNING

The object of the invention is to configure a percussion mechanism in such a way that the number of blows - and hence the return stroke and the individual impact energy of the percussion piston - is matched automatically to changing working conditions via an internal control system as a function of the contact pressure on the tool insertion end. For this purpose the invention proposes to hold a contact-pressure control element (31) at least temporarily in contact with the insertion end (12) under the action of a resetting arrangement (31a, 22) acting in the striking direction (arrow 18) and, via this contact-pressure control element, to connect a control conduit (35) either to a pressure conduit (22) or to a balanced return conduit (25). Via the control conduit, a switching element (30) can be actuated in such a way that the control device (4) alternately switching over the movement of the piston performs the reversing movement into the working-stroke position at an earlier or later point in time during the return stroke (arrow 19) of the percussion piston, thereby triggering the working stroke of the percussion piston in the striking direction.