Hammering device and a method for operating a hammering device

Abstract

Disclosed is a hammering device ( 1 ) comprising a hammer ( 2 ) connected to a winch ( 3 ) by means of cable means ( 4 ), wherein the rotation of the winch ( 3 ) is driven by one or more hydraulic motors ( 5 ), and wherein the hammering device ( 1 ) further comprises position detection means ( 6 ) for detecting a position of the hammer ( 2 ). Furthermore, a method for operating a hammering device ( 1 ) is disclosed.

1 . A hammering device comprising
 a hammer connected to a winch by means of cable means,   wherein the rotation of said winch is driven by one or more hydraulic motors, and   wherein said hammering device further comprises position detection means for detecting a position of said hammer.   
     
     
         2 . A hammering device according to  claim 1 , wherein said hammering device further comprises winch rotation braking means. 
     
     
         3 . A hammering device according to  claim 1 , wherein said hammering device further comprises control means for activating said winch rotation braking means in accordance with an input from said position detection means. 
     
     
         4 . A hammering device according to  claim 3 , wherein said control means comprises reset means for resetting said position detection means when said hammer reached impact. 
     
     
         5 . A hammering device according to  claim 1 , wherein said hammering device comprises direct short circuit flow path means for optionally creating a direct short circuit flow path between an input port and an output port of said hydraulic motor. 
     
     
         6 . A hammering device according to  claim 2 , wherein said winch rotation braking means comprises short circuit flow path blocking means for blocking a flow through said short circuit flow path. 
     
     
         7 . A hammering device according to  claim 5 , wherein said direct short circuit flow path means comprises overpressure relieve means. 
     
     
         8 . A hammering device according to  claim 7 , wherein said overpressure relieve means is arranged to relieve the pressure in said direct short circuit flow path if said pressure exceeds 700 Bar, preferably if said pressure exceeds 500 Bar and most preferred if said pressure exceeds 300 Bar. 
     
     
         9 . A hammering device according to  claim 5 , wherein said direct short circuit flow path means comprises refilling means for increasing the pressure in said direct short circuit flow path. 
     
     
         10 . A hammering device according to  claim 1 , wherein said winch is driven by more than one hydraulic motor. 
     
     
         11 . A hammering device according to  claim 10 , wherein at least one of said more than one hydraulic motor comprises freewheeling means. 
     
     
         12 . A hammering device according to  claim 10 , wherein said freewheeling means comprises means for connecting an output port of said hydraulic motor to tank means. 
     
     
         13 . A method for operating a hammering device, said method comprising the steps of:
 lifting a hammer of said hammering device to a predetermined initial position by means of winch means driven by at least one hydraulic motor,   dropping said hammer by creating a direct short circuit flow path between an input port and an output port of said hydraulic motor, and   breaking or reducing a flow through said direct short circuit flow path before said hammer reaches impact.   
     
     
         14 . A method according to  claim 13 , wherein said method further comprises the step of detecting a position of said hammer at least during said drop. 
     
     
         15 . A method according to  claim 14 , wherein said flow through said direct short circuit flow path if broken or reduced in response to said detected position of said hammer. 
     
     
         16 . A method according to  claim 15 , wherein said breaking or reducing said flow through said direct short circuit flow path is initiated in response to the latest impact position of said hammer. 
     
     
         17 . A method according to  claim 13 , wherein said predetermined initial position is selected manually by an operator. 
     
     
         18 . A method according to  claim 13 , wherein said hammering device is a hammering device according to  claim 1 .