| 摘要 |
A plunger mechanism for use in forming a gob of molten glass into a parison comprises a cylinder (30), a piston (32) movable in the cylinder upon the introduction of hydraulic fluid, a piston rod (34), means (40) for mounting a plunger on the piston rod, a servo-mechanism (58) to control the flow of fluid, a position or velocity feedback device (60), and control means (70) responsive to the feedback device operable to control the servo-mechanism so that the plunger moves with a predetermined position against time curve. |
