Hand machine tool with a hammer mechanism

Abstract

A hand machine tool is equipped with a hammer mechanism, which has a hammer ( 1 ) that moves axially back and forth in a guide tube ( 2 ); a spring mechanism ( 4 ) is provided, which exerts a force on the hammer ( 1 ) and can set the hammer ( 1 ) into a movement toward a tool ( 3 ) that can be inserted into the hand machine tool. The hammer mechanism produces a very high individual hammering energy at a relatively low hammering frequency by virtue of the fact that after each impact, the hammer ( 1 ) is set into a motion counter to the force of the spring mechanism ( 4 ) in order to stress this spring mechanism and after the stressing of the spring mechanism ( 4 ), the hammer ( 1 ) is abruptly released again so that it flies toward the tool ( 3 ).

1 . A hand machine tool—preferably a hammer drill and/or slide hammer—equipped with a hammer mechanism, which has a hammer ( 1 ) that moves axially back and forth in a guide tube ( 2 ); a spring mechanism ( 4 ,  15 ,  16 ) is provided, which exerts a force on the hammer ( 1 ) and can set the hammer ( 1 ) into a movement toward a tool ( 3 ) that can be inserted into the hand machine tool, wherein means ( 8 ,  10 ,  13 ,  14 ) are provided, which set the hammer ( 1 ) into a motion counter to the force of the spring mechanism ( 4 ,  15 ,  16 ) after each impact in order to stress this spring mechanism and, after the stressing of the spring mechanism ( 4 ,  15 ,  16 ), these means ( 8 ,  10 ,  13 ,  14 ) abruptly release the hammer ( 1 ) again so that, driven by the spring mechanism ( 4 ,  15 ,  16 ), it flies toward the tool ( 3 ).  
   
   
       2 . The hand machine tool as recited in  claim 1 , 
 wherein the means ( 8 ,  10 ,  13 ,  14 ) are comprised of a drive mechanism that produces a frictional engagement with the hammer ( 1 ) after an impact has been imparted, moves it counter to the force of the spring mechanism ( 4 ,  15 ,  16 ), and then releases the frictional engagement again as soon as the hammer ( 1 ) has reached a certain position in its movement counter to the force of the spring mechanism ( 4 ,  15 ,  16 ).    
   
   
       3 . The hand machine tool as recited in  claim 1 , 
 wherein the spring mechanism ( 4 ,  15 ,  16 ) is comprised of a pressure reservoir ( 4 ), which is filled with a compressible medium and is situated in the guide tube ( 2 ) on the side of the hammer ( 1 ) oriented away from the tool ( 3 ).    
   
   
       4 . The hand machine tool as recited in  claim 3 , 
 wherein a pump ( 7 ) is able to supply compressible medium to the pressure reservoir ( 4 ).    
   
   
       5 . The hand machine tool as recited in  claim 1 , 
 wherein the spring mechanism ( 14 ,  15 ) is comprised of one or more compression springs ( 15 ) and/or tension springs ( 16 ), which is/are supported against the hammer ( 1 ) on the one hand and against a shoulder ( 5 ,  17 ) that is stationary in the movement direction of the hammer ( 1 ) on the other hand.