High vacuum gate valve having improved metal vacuum joint

A two part high vacuum gate valve construction comprising a control mechanism part and a valve body part,

• the control mechanism part including a linearly translatable control stem shaft, and a first generally rectangular high vacuum joint providing flange having a central opening through which the shaft freely passes, and a high vacuum joint providing geometry on the other major face thereof enabling said control mechanism part to be removably joined to and sealed with said valve body part, and displacement means for controllably displacing said shaft,
• the valve body part including
• a generally rectangular case secured at an upper end to a second generally rectangular high vacuum joint providing flange having a mirror image sealing geometry to said first high vacuum joint providing flange,
• two machined fluid flow flanges passing through openings defined through opposite sidewalls of said case and sealed thereto, at least one of the fluid flow flanges having an inside gate sealing surface machined prior to insertion through and sealing of the flange to the sidewall of the case, the fluid flow flanges defining central flow passages and including outer sealing means enabling formation of high vacuum joints with piping to which the valve may be operationally attached,
• two part, levered carriage means having a central transverse pivot joint and having endwall engagement means for causing said pivot joint to pivot toward said inside gate sealing surface of the one flow flange in response to continued actuation force supplied by said control stem shaft after an inside endwall of said case has been contacted,
• a valve gate having a sealing surface for engaging the inside gate sealing surface of the one flow flange when the carriage means is opposite the other flow flange and having a back surface with pivoted engagement means, the engagement means engaging the carriage means at the central transverse pivot joint,
• double jointed linkage assembly means having one link part pivotally fixed to said second flange and linked to said control stem shaft for double jointed arcuate movement as said shaft is moved along its locus of rectilinear limited displacement, and having a second link part linked to said first link part and to said carriage means, for levering actuation force supplied by the central stem shaft to the carriage means thereby to cause said gate to close and then seal.