| AVS 56th International Symposium & Exhibition | |
| Vacuum Technology | Tuesday Sessions |
| Session VT-TuP |
| Session: | Vacuum Technology Posters and Student-Built Vacuum Systems Poster Competition |
| Presenter: | E. Trillwood, CEO Electron Beam Engineering |
| Correspondent: | Click to Email |
The novel device uses a piston and a cylinder, both with seals to penetrate the wall of a high vacuum processing chamber. The piston is hollowed out for a portion of its length and the component to be processed in the chamber is placed in this cavity, or breach. The piston, as it moves into the chamber, passes over a pre pumping station which is fitted with a two stage mechanical pump to pre evacuate the breach. Since the volume closely fits the component the evacuation time is usually one second or less. When the component enters the chamber "volume sharing" occurs and the resulting pressure rise is very small and rapid as the chamber high vacuum pumps the differential pressure between the breach and the chamber.
The seals are placed in such a manner as to isolate the atmosphere, the pre pumping and the chamber vacuums from each other at all times in the cycle.
On completion of the process the piston is withdrawn from the chamber and the breach returned to atmosphere.
Apart from the speed of operation the system has the advantage of being self valving and if a second breach or dummy piston is added to the opposite side of the chamber the forces on the piston due to atmospheric pressure are equalized and the force required to transfer the piston is greatly reduced.
This system has been used successfully in production Electron Beam Welding but has many other potential uses where ease and speed of loading and unloading relatively small parts into a vacuum chamber is requied.