Printed circuit board testing means

A circuit board test fixture which comprises:

• a housing;
• a pair of generally opposed and parallel platen members carried therein with at least one of said platen members movably mounted in said housing with peripheral flange means and an integral central boss carried by said member, said central boss received within a coextensive, central cavity formed by the facing interior wall of said housing and spaced apart from the bottom of said central cavity to define a central chamber therein;
• guide rail means on opposite sides of the movable platen member and connected by guide pins at opposite ends thereof between said movable platen member and housing to maintain said platen members in parallel alignment during movement of said movable platen member;
• means for supporting a circuit board against one of said platen members;
• means for supporting on the other of said platen members pressured contact units juxtaposed towards said circuit board;
• fluid-sealed expansion means within said chamber;
• and
• means communicting with said fluid-sealed means exteriorly of said chamber for sending pressured fluid into said sealed expansion means to impart relative movement to said platen members and direct said contact units against circuitry of said circuit board.