| 摘要 |
The plunger mechanism is for use in moving a plunger into or out of a mould cavity and has a piston movable in a cylinder with a piston rod projecting from the piston. A plunger can be mounted on the piston rod. A passage passes through the piston and the piston rod and communicates with a chamber in the plunger or with the mould cavity. A tube which can be connected to a source of air under pressure or to a vacuum source passes through the cylinder and enters the passage. The gap between the passage and the tube is sealed by an inwardly-contracting ring with an overlapping joint which makes sealing contact around the tube. A ring of resilient material may encircle the inwardly-contracting ring to seal the gap between the inwardly-contracting ring and the wall of a recess in which it is mounted. |
