Motor driven drilling hammer

Abstract

The invention concerns a motor-driven drilling hammer with percussion and rotary drive, and a drill sleeve ( 14 ) which is disposed in a housing and is drivingly connected to a tool or a chuck for receiving the tool. In order to improve vibration damping, the drilling hammer is designed such that the drill sleeve ( 14 ) is connected on its outer periphery ( 30 ) to a spring means ( 32 ) of an elastomeric material ( 34 ) which has a wall thickness of 1 to 10 mm, and wherein the spring means ( 32 ) holds a damping mass ( 36 ) which can be deflected relative to the drill sleeve ( 14 ) in the peripheral direction and in the longitudinal direction ( 20 ) of the drill sleeve ( 14 ) due to the elasticity of the spring means ( 32 ), thereby effecting damping and reduction of vibration.

1 . A motor-driven drilling hammer for driving a tool or a chuck receiving a tool, the drilling hammer comprising: 
 a housing;    a percussion and rotary drive disposed in said housing;    a drill sleeve disposed in said housing and cooperating with said percussion and rotary drive and with the tool or the chuck for receiving the tool;    a spring means having an elastomeric material with a wall thickness of 1 to 10 mm, said spring means connected to an outer periphery of said drill sleeve; and    a damping mass held by said spring means for deflection of said damping mass relative to said drill sleeve in a peripheral and longitudinal direction of said drill sleeve due to an elasticity of said spring means, thereby effecting damping and reduction of vibrations.    
   
   
       2 . The drilling hammer of  claim 1 , wherein said elastomeric material continuously surrounds said drill sleeve in said peripheral direction and is substantially cylindrical.  
   
   
       3 . The drilling hammer of  claim 1 , wherein said elastomeric material is segmented.  
   
   
       4 . The drilling hammer of  claim 1 , wherein said elastomeric material has perforations, recesses or openings in a radial, tangential, or axial direction.  
   
   
       5 . The drilling hammer of  claim 1 , wherein said elastomeric material has a wall thickness of 4 to 8 mm.  
   
   
       6 . The drilling hammer of  claim 1 , wherein said elastomeric material has an axial extension in said longitudinal direction of said drill sleeve of 5 to 20 mm.  
   
   
       7 . The drilling hammer of  claim 1 , wherein said damping mass is substantially cylindrical.  
   
   
       8 . The drilling hammer of  claim 1 , wherein said damping mass has an axial extension in said longitudinal direction of said drill sleeve of 5 to 20 mm.  
   
   
       9 . The drilling hammer of  claim 1 , wherein said damping mass has an axial extension in said longitudinal direction of said drill sleeve, which is 3 to 8 times a wall thickness thereof.  
   
   
       10 . The drilling hammer of  claim 1 , wherein said damping mass and said spring means are designed to damp vibrations of between 30 and 100 Hz or, for small drilling hammers, between 70 to 80 Hz.