Patent ID: 6932111
Filing Date: 2005-08-23
Classification: F16K,Y10T

Abstract:
1. A gate valve apparatus comprising: a valve body having a rectilinear exhaust flow path formed therein to extend from a chamber port to a pump port; and a main valve provided in said valve body, said main valve including a main valve element and a main valve seat, said main valve element being movable within a travel space in a direction parallel to an axis of said exhaust flow path, so that when said main valve element is in a sealing position, a main valve seal for said main valve element contacts said main valve seat to block communication through said exhaust flow path, and when it is in a non-sealing position, said main valve element is separated from said main valve seat by a predetermined distance and moved in a direction perpendicular to the axis of said exhaust flow path so as to be accommodated in an accommodating chamber; wherein said main valve seal is provided on an abutting surface of said main valve element, and an annular projection is provided on an inner wall surface of said accommodating chamber, so that when it is in the non-sealing position, said main valve element is moved toward the inner wall surface of said accommodating chamber to bring an outer peripheral portion of said main valve element into contact with said annular projection, whereby said main valve seal is shielded from radicals and plasma in exhaust gas by said main valve element, said annular projection and the inner wall surface of said accommodating chamber.