EP 0827813 A3 20000412 - Hydraulically actuated mechanism with automatic stroke change

Title (en)

Hydraulically actuated mechanism with automatic stroke change

Title (de)

Fluidbetriebenes Schlagwerk mit automatischer Hubumschaltung

Title (fr)

Dispositif hydraulique à percussion avec inversion automatique de la course du piston

Publication

EP 0827813 A3 20000412 (DE)

Application

EP 97114714 A 19970826

Priority

DE 19636659 A 19960910

Abstract (en)

[origin: EP0827813A2] The hammer mechanism (1) has a striking piston (3) moving alternately through working strokes and return strokes under the influence of a control valve (5). The control unit is itself influenced by a servo valve (14) with a returning device (17, 17a) which can be in locked position or open position, depending on the setting of the striking piston. When the piston limit setting in the direction of the working stroke (3e) is exceeded, the control valve is changed to the return stroke setting. During the return stroke immediately following, a short stroke line (18) pressurises the control valve in advance into the working stroke position so that the piston only makes a short stroke.

IPC 1-7

B25D 9/14

IPC 8 full level

B25D 9/14 (2006.01); E21B 1/26 (2006.01); E21C 37/24 (2006.01)

CPC (source: EP US)

B25D 9/14 (2013.01 - EP US)

Citation (search report)

[AD] DE 3443542 A1 19860605 - KRUPP GMBH [DE]
[A] EP 0688636 A1 19951227 - BRETEC OY [FI]
[A] US 4281587 A 19810804 - GARCIA-CRESPO JOSE T
[A] EP 0587079 A2 19940316 - KLEMM GUENTER [DE]
[A] PATENT ABSTRACTS OF JAPAN vol. 1998, no. 08 30 June 1998 (1998-06-30)

Designated contracting state (EPC)

AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

DOCDB simple family (publication)

EP 0827813 A2 19980311; EP 0827813 A3 20000412; EP 0827813 B1 20030319; AT E234707 T1 20030415; DE 19636659 A1 19980312; DE 19636659 C2 20001123; DE 59709545 D1 20030424; ES 2189907 T3 20030716; US 5860481 A 19990119

DOCDB simple family (application)

EP 97114714 A 19970826; AT 97114714 T 19970826; DE 19636659 A 19960910; DE 59709545 T 19970826; ES 97114714 T 19970826; US 92111397 A 19970829