Puller

A puller comprising:

• a collar comprising slots and pivotal connectors located corresponding to the slots;
• claws pivotally connected to the pivotal connectors, wherein each of the claws comprises a protuberance movable in a corresponding one of the slots;
• a synchronizer comprising a receiving portion for receiving the protuberances, wherein the synchronizer is movable in the collar between an opening position and a closing position, wherein the synchronizer opens the claws by the protuberances in the opening position, wherein the synchronizer closes the claws by the protuberances in the closing position;
• an abutting assembly inserted in and engaged with the collar for causing the synchronizer to move, wherein the abutting assembly comprises a cylinder inserted in and connected to the collar, a piston tube extensible from the cylinder, and a threaded rod extensible from the piston tube for abutting an axle;
• and
• a restraint assembly comprising a cap covers the cylinder and inserted in the synchronizer and a restraint abuts against the cap and movable engaged with the threaded rod,
• wherein a hydraulic pressure in the cylinder is increased, causing the piston tube to be extended from the cylinder, the restraint assembly to drive the synchronizer opens the claws;
• the hydraulic pressure in the cylinder is reduced, causing the piston tube to be retracted into the cylinder, the synchronizer closes the claws so that the claws are engaged with an annular element;
• and the restraint is moved away from the cap, the threaded rod abuts against the axle, the hydraulic pressure in the cylinder increases, the piston tube and the threaded rod extend from the cylinder, and the axle is pushed by the threaded rod and separated from the annular element.