Patent ID: 7082800

Claim:
A device for mounting and demounting a bearing unit of a back-up roll of a roll stand, the bearing unit being comprised of a chock with a roll pin bearing arranged in the chock, the device comprising a change-over device comprising coupling means for temporarily coupling the change-over device with the bearing unit, wherein the change-over device has means for generating an axial movement in the direction toward the back-up roll for pushing the bearing unit onto the roll pin and away from the back-up roll for pushing the bearing unit from the roll pin, the coupling means of the change-over device comprising only two sets of claws that include lever-like inner claws and lever-like outer claws, wherein the inner claws engage a pin end of the back-up roll and the outer claws engage the bearing unit, wherein the inner and outer claws are rotatable and are lockable by bayonet closures in the pin end and in the bearing unit, respectfully, wherein the pin end and an intermediate ring connected to an outer side of the bearing unit are cloverleaf-shaped with through grooves for the inner and outer claws, wherein, after rotating the change-over device into an engagement position, complementary locking projections of the pin end and of the intermediate ring, respectively, are provided for the claws, and wherein a pressure ring connected in front of the roll pin bearing is positioned opposite the outer claws.