초록 ▼

A rotary hammer with a pneumatic impact mechanism carries on a drive shaft, non-rotatably and non-displaceable axially relative thereto, a coupling element as well as, rotatably and displaceable axially relative thereto, a drive element. The drive element has a peripheral drive fin constituting a ca

A rotary hammer with a pneumatic impact mechanism carries on a drive shaft, non-rotatably and non-displaceable axially relative thereto, a coupling element as well as, rotatably and displaceable axially relative thereto, a drive element. The drive element has a peripheral drive fin constituting a cam/control curve which engages between two rollers. The rollers are mounted on the rear end of a piston of the pneumatic impact mechanism with their axes of rotation perpendicular to the longitudinal axis of the piston. The drive element can at choice be brought into engagement with the coupling element. A manually operable control member may be operated to maintain the drive element out of such engagement.

대표청구항 ▼

A rotary hammer, comprising: a housing; a piston reciprocally mounted in said housing for, in use, driving a beat piece; a rotatable drive element having a continuous fin around its circumference which cooperates with said piston so that as said drive element is rotated said piston moves back and fo

A rotary hammer, comprising: a housing; a piston reciprocally mounted in said housing for, in use, driving a beat piece; a rotatable drive element having a continuous fin around its circumference which cooperates with said piston so that as said drive element is rotated said piston moves back and forth in said housing; said piston being provided with a pair of rollers which are disposed to opposite sides of and drivingly engaged by said fin; said drive element being rotatably mounted on a drive shaft provided with a coupling element fast thereon, and said drive element being displaceable axially along said shaft for bringing said drive element into and out of driving engagement with said coupling element; a spring disposed between said coupling element and said drive elment and biasing them apart; a rotatable tool spindle mounted in said housing and axially displaceable therein by contact pressure between a workpiece and a tool mounted in said rotary hammer to urge said drive element into driving engagement with said coupling element; movement of said tool spindle being transmitted to said drive element by a separating disk; said disk having two spaced apart holes therein through which extend respectively said tool spindle and said drive shaft, said tool spindle and said drive shaft being rotatable in said holes; and one side of said disk being acted upon by said tool spindle via a first needle bearing and an opposite side of said disk acting upon said drive element via a second needle bearing.