The present invention relates to a pipe feeding machine in which the frame is equipped with plural conveying devices, plural lifting plates, plural pipe diameter limiting devices, a group loading device and an independent loading device; wherein the conveying device comprises a conveying belt, and the group and independent loading devices comprise a pusher plate and a positioning plate; when the lifting plate with the pipes is raised to the plane of the conveying belt and the pipes are conveyed between the pusher plate and positioning plate, which is able to further transport a single pipe to the center of the chuck assembly for processing, which replaces the conventional feeding belt to avoid the collision during the lifting and conveying of the pipes, and to improve the efficiency and yield of pipe production.

The present invention relates to a pipe feeding machine in which the frame is equipped with plural conveying devices, plural lifting plates, plural pipe diameter limiting devices, a group loading device and an independent loading device; wherein the conveying device comprises a conveying belt, and the group and independent loading devices comprise a pusher plate and a positioning plate; when the lifting plate with the pipes is raised to the plane of the conveying belt and the pipes are conveyed between the pusher plate and positioning plate, which is able to further transport a single pipe to the center of the chuck assembly for processing, which replaces the conventional feeding belt to avoid the collision during the lifting and conveying of the pipes, and to improve the efficiency and yield of pipe production.

A cam mechanism includes a base, a roller gear, and a camshaft. The roller gear and the camshaft are rotatably supported by the base. The roller gear has a turret and a plurality of cam followers mounted on the circumference of the turret. The camshaft has a shaft portion and a tapered rib having a first tapered rib and a second tapered rib. The first and second tapered ribs are each engaged with the cam followers. The first and second tapered ribs are configured to rotate relative to each other around a rotation axis of the shaft portion during adjustment of preload at which the first and second tapered ribs are pressed against the cam followers. After the adjustment of the preload, the second tapered rib is fixed to the shaft portion, and the first and second tapered ribs are prevented from rotating relatively.