Patent ID: 7257895

Claim:
An apparatus for cutting a workpiece ( 1 ), said apparatus adapted to engage said workpiece at four points of surface engagement thereof, said apparatus comprising a clamping mechanism ( 2 ) adapted to be fastened to said workpiece ( 1 ) rotatably therearound and said clamping mechanism ( 2 ) having attached thereto a tool unit ( 3 ), which is provided with adjustment means ( 4 ) for displacing said tool unit ( 3 ) relative to the clamping mechanism ( 2 ) towards or away from the workpiece ( 1 ), and said clamping mechanism ( 2 ) including a frame element ( 5 ) and first and second arms ( 6 , 7 ) extending therefrom, said arms ( 6 , 7 ) being articulated at one end to the frame element ( 5 ) of the clamping mechanism ( 2 ) and each arm ( 6 , 7 ) has its free end fitted with a bearing axle ( 31 , 32 ) respectively, which is provided each with one bearing wheel ( 15 , 16 ) respectively wherein each of said bearing wheels ( 15 , 16 ) provide one point of said four points of surface engagement, the clamping mechanism ( 2 ) having its frame element ( 5 ) provided in a rotatable and axially immobile fashion with a threaded shaft ( 20 ), whose first end has a right-handed thread provided with a first nut ( 21 ) and whose second end has a left-handed thread provided with a second nut ( 22 ), and said threaded shaft ( 20 ) being provided with a member ( 23 ) for rotating the threaded shaft ( 20 ), and the first arm ( 6 ) and the first nut ( 21 ) are attached to each other by means of a first suspension arm ( 24 ) and the second arm ( 7 ) and the second nut ( 22 ) are attached to each other by means of a second suspension arm ( 25 ), characterized in that the apparatus further comprises two second bearing axles ( 33 , 34 ), fitted adjustably relative to their mutual distance between the arms ( 6 , 7 ) respectively one attached to each suspension arm ( 24 , 25 ) and the frame element ( 5 ), each of said second bearing axles being provided with at least one bearing wheel ( 35 , 36 ) respectively wherein each of said wheels provides one point of said four points of surface engagement.