High vacuum gate valve having improved metal vacuum joint

Abstract

A two part high vacuum gate valve construction includes a control mechanism part having a limited displacement stem passing through a first generally rectangular high vacuum flange and a valve body part including a generally rectangular case, a second generally rectangular high vacuum joint providing flange having a mirror image sealing geometry to the first high vacuum 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; a two part, levered carriage having a central transverse pivot joint and having an endwall engagement mechanims for causing the pivot joint to pivot toward the inside gate sealing surface of the one flow flange in response to continued actuation force supplied by the 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 the gate being pivotally attached to the carriage at the central transverse pivot joint, a double jointed linkage assembly having one link part pivotally fixed to the second flange and linked to the control stem shaft for double jointed arcuate movement as the shaft is moved along its locus of rectilinear limited displacement, and having a second link part linked to the first link part and to the carriage means, for levering actuation force supplied by the central stem shaft to the carriage thereby to cause the gate to close and then to seal.