Patent ID: 7237567

Claim:
A vacuum valve comprising: a body having a cavity at an interior thereof, said body having a bottom provided with a first air hole and two vertical sides provided with two second air holes; a cylinder positioned on said body, said cylinder being provided with a piston having a piston rod, said piston rod having a lower end which extends downwardly into said body; a protruded seat connected with said lower end by a connection rod; a gate plate mounted on a bottom of said protruded seat and provided with two pulleys, one at each end of said gate plate, said gate plate being adapted to close said first air hole of said body; two sliding slots formed on two opposite inner sides of said cavity of said body; said two pulleys each being slidably fitted in a respective one of said sliding slots; and a sealing plate adapted to be mounted on said body to close one of said first and second air holes as required.