Institut Cerac Sa

Karl G Ragnmark

Carl S Hartwig

A hand-held electrically powered hammer tool with a rotor-type electromotor (17) and a hammer mechanism (14) arranged in a machine housing (13). The hammer mechanism (14) includes a drive shaft (24) with an excentric crank pin (35) thereon for a piston rod (43) connected to a drive piston (40) reciprocably movable in a cylinder (42) for driving a hammer piston (41) towards a working tool (16) via an air cushion (44) between the two pistons. The drive shaft for the hammer mechanism (14) is also the rotor shaft of the electromotor (17) so that the hammer mechanism and the motor are driven by the same speed. The electromagnetically active parts (23,49) of the rotor (18) are located outside of and surround the corresponding parts (21, 22) of the electromotor stator (19) thus enabling the rotor also to be a flywheel and a fanwheel.

Growing community of inventors

Kalmar, Sweden

Karl G Ragnmark