High-vacuum valve with retractable valve plate to eliminate abrasion

A high-vacuum valve comprising

• a valve body having a flow channel;
• a composite valve plate disposed within said valve body and movable in a direction transverse to said flow channel between a closed position traversing said flow channel to prevent flow therethrough and an open position sufficiently clearing said flow channel to permit flow therethrough, said composite valve plate comprising:
• a seal plate;
• a support block;
• a resilient connector having a first end affixed to one of said seal plate and said support block and a second end terminating in a chamber in the other of said seal plate and said support block, said resilient connector arranged such that when relaxed said resilient connector exerts an expanding force urging said seal plate and said support block apart;
• sealing means disposed between said second end of said resilient connector and inner walls of said chamber;
• and
• a passageway arranged to supply pressurized fluid to one side of said sealing means to thereby impose across said sealing means a pressure differential that compresses said resilient connector in opposition to said expanding force and thereby urges said seal plate and said support block toward each other;
• and
• means for supplying pressurized fluid to said passageway and for releasing pressurized fluid therefrom upon command.