Hand-held electric machine tool comprising a dust collection container and a level indicator

Abstract

An electric hand-held power tool is described that has a machine housing ( 11 ) with an integral dust-ejection connection ( 15 ) and a dust collection container ( 16 ) attached thereto. To ensure, when working with the electric hand-held power tool, that the dust collection container ( 16 ) is emptied in time when full, a fill level indicator is provided that indicates, at the least, the maximum amount of dust allowed in the dust collection container ( 16 ). The fill level indicator ( 20 ) is preferably integrated in the machine housing ( 11 ) and includes a pressure sensor ( 21 ) that measures the pressure in the dust-ejection connections ( 15 ), and a display unt ( 22 ) that is actuated as a function of the pressure measured (FIG. 1 ).

1 . An electric hand-held power tool with a machine housing ( 11 ) with an integral dust-ejection connection ( 15 ) and a dust collection container ( 16 ) attached to the dust-ejection connection ( 15 ), characterized by a fill level indicator ( 20 ) that indicates, at the least, the maximum allowed dust load of the dust collection container ( 16 ).  
   
   
       2 . The electric hand-held power tool as recited in  claim 1 , wherein the fill level indicator ( 20 ) is integrated in the machine housing ( 11 ).  
   
   
       3 . The electric hand-held power tool as recited in  claim 2 , wherein the fill level indicator ( 20 ) includes a pressure sensor ( 21 ) that measures the pressure in the dust-ejection connection ( 15 ), the pressure sensor generating an output value that is proportional to the measured pressure, and including a display unit ( 22 ) controlled by the output value.  
   
   
       4 . The electric hand-held power tool as recited in  claim 3 , wherein the pressure sensor ( 21 ) is located in the machine housing ( 11 ) and detects the pressure in the dust-ejection connection ( 15 ) via a duct ( 24 ) in the machine housing ( 11 ) that leads into the dust-ejection connection ( 15 ).  
   
   
       5 . The electric hand-held power tool as recited in  claim 2 ,  
     wherein the display unit ( 22 ) is visible on the machine housing ( 11 ), being located preferably above a handle ( 17 ) formed on the machine housing ( 11 ).  
   
   
       6 . The electric hand-held power tool as recited in  claim 3 ,  
     wherein the pressure sensor ( 21 ) is an electromechanical pressure sensor, with which a pressure chamber ( 42 ) bounded by a diaphragm ( 32 ) or a displacement piston ( 41 ) is acted upon by the pressure in the dust-ejection connection ( 15 ) and which is preloaded via a spring ( 38 ) against the pressure in the pressure chamber ( 42 ), and a contact member of a break contact located in the circuit of an electrical display unit ( 22 ) is coupled to the diaphragm ( 32 ) or displacement piston ( 41 ), the contact member closing when the diaphragm ( 32 ) or displacement piston ( 41 ) is displaced to a specified extent.  
   
   
       7 . The electric hand-held power tool as recited in  claim 6 , wherein the maximum displacement of the diaphragm ( 32 ) or displacement piston ( 41 ) is adjusted such that, when the pressure in the pressure chamber ( 42 ) corresponds to the pressure that exists in the dust-ejection connection ( 15 ) when the dust collection container ( 16 ) is filled to the maximum level, the break contact closes.  
   
   
       8 . The electric hand-held power tool as recited in  claim 3 ,  
     wherein the pressure sensor ( 21 ) is a mechanical pressure sensor with a displacement piston ( 41 ) acted upon by the pressure in the dust-ejection connection ( 15 ), and the display unit ( 22 ) is a device that displays the displacement travel of the displacement piston ( 41 ) as the fill level amount in the dust collection container ( 16 ).  
   
   
       9 . The electric hand-held power tool as recited in  claim 3 ,  
     wherein the pressure sensor ( 21 ) is a piezoelectric pressure-measuring cell.  
   
   
       10 . The electric hand-held power tool as recited in  claim 1 ,  
     wherein a fan wheel ( 14 ) of a suction fan is located in the machine housing ( 11 ), the fan wheel ( 14 ) drawing in dust from the surface of a machined workpiece and blowing it into the dust collection container ( 16 ) via the dust-ejection connection ( 15 ).