| 摘要 |
A tire curing press with an improved loader includes a shaping or center mechanism which includes a vertically movable well on which is mounted the bottom bead or toe ring. The press includes a loader of improved design affording precision centering and accuracy which is driven for vertical movement by a ball screw and nut drive which positions the green tire concentric with the upper and lower mold sections and over the bottom bead ring. The loader then moves the green tire downwardly until the lower bead of the green tire reaches a predetermined point touching or fairly closely adjacent the elevated bead ring. Simultaneously, an adjustable pad on the loader contacts the tip of an extended rod of a vertically oriented synchronizer piston-cylinder assembly. Concurrently, a sensor is tripped to power the synchronizer piston downwardly and as such piston moves downwardly, the loader follows at a slightly higher speed causing the rotary motor of the ball screw drive to be retarded or stall, thus keeping the loader in contact with the tip of the rod of the synchronizer cylinder assembly. As the synchronizer piston is being powered down, fluid on the underside of such piston is being forced over to the top ports of a pair of bead lift cylinder assemblies causing them to bring the well and thus the lower bead ring down at the same speed as the loader is bringing the tire down. In this manner the green tire and lower bead ring are maintained in constant relationship until the bead ring is seated on the lower mold section. The point of bead ring seating provides a physical stop which in turn blocks the synchronizer piston and rod, and thus the loader from further downward travel. This synchronization is accomplished by making the blind end area of the piston of the synchronizing cylinder assembly twice the equal rod end areas of the pistons of the bead lift cylinders. |
