EP 0088705 B1 19851211 - DOWN-THE-HOLE PNEUMATIC HAMMER
Title (en)
DOWN-THE-HOLE PNEUMATIC HAMMER
Publication
Application
Priority
FR 8204077 A 19820311
Abstract (en)
[origin: EP0088705A1] 1. Down-the-hole pneumatic drilling hammer, which comprises a tubular body (1) supplied with compressed air and carrying a drilling bit (3) and in which a ramming piston (21) is made to perform a reciprocating movement inside an internal sleeve (7) forming a casing by means of a mechanism for distributing compressed air alternately above and below the ramming piston in such a way that it cyclically strikes the bit and rises again, characterised in that the hammer has two separate sources (16, 18) of compressed air, a high-pressure one and a low-pressure one respectively, the distribution mechanism ensuring alternately the supply of high-pressure air to the upper chamber (51) above the piston (21) so as to project the latter towards the bit, while the lower chamber (50) allows the air to escape, and the supply of low-pressure air to the lower chamber (50) so as to cause the piston (21) to rise again, while the upper chamber (51) allows the air to escape.
IPC 1-7
IPC 8 full level
E21B 4/14 (2006.01); E21B 21/12 (2006.01); E21B 21/14 (2006.01)
CPC (source: EP)
E21B 4/14 (2013.01); E21B 21/12 (2013.01); E21B 21/14 (2013.01)
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI LU NL SE
DOCDB simple family (publication)
EP 0088705 A1 19830914; EP 0088705 B1 19851211; AT E16954 T1 19851215; DE 3361460 D1 19860123; FR 2523202 A1 19830916; FR 2523202 B1 19840413
DOCDB simple family (application)
EP 83400495 A 19830311; AT 83400495 T 19830311; DE 3361460 T 19830311; FR 8204077 A 19820311