Patent ID: 7014547

Claim:
A portable grinding machine ( 10 ), comprising: an elongated housing ( 12 , 14 ) and an output shaft ( 16 ) accommodated in the housing for receiving a disk-shaped rotary clamping tool, wherein the output shaft is encompassed by a substantially cylindrical clamping collar ( 30 ), on which a shell-like protective cover ( 20 ) is secured in a tensile manner against rotation and axial displacement, wherein said protective cover serves to encompass the clamping tool and, by means of a ring-shaped tensioning belt ( 28 ), is attached to the clamping collar ( 30 ), wherein the tensioning belt ( 28 ) has sharp-edged projections ( 32 ) projecting to the clamping collar, which upon clamping, bore into the clamping collar ( 30 ) and are held tightly in a form-locking manner onto the clamping collar, wherein the tensioning belt is made from sheet metal and the projections are pressed tongues ( 32 ) with at least one sharp tip or edge, wherein the at least one sharp edge or tip is arranged counter to a preferred direction of rotation of the protective cover ( 20 ) to enter the clamping collar at an incline, so that the protective cover ( 20 ) only is rotatable in the preferred direction against a direction of rotation of a grinding wheel.