Patent ID: 6174484
Filing Date: 2001-01-16
Classification: B29C,B29L

Abstract:
A compression molding apparatus, comprising:a mold made of a first material having a first coefficient of thermal expansion;a plug made of a second material having a second coefficient of thermal expansion different from said first coefficient of thermal expansion of said first material of said mold, one of said mold and plug having a cavity into which the other of said mold and plug is placed such that the one is disposed relative to the other along a central longitudinal axis so to provide a gap between said mold and plug having a first volume for holding a body of a third material different from the first and second materials at least partially filling said gap when said mold and plug are at a first temperature and for molding the body into a molded product when said mold and plug are subjected to a second temperature that causes one of said first and second materials of said mold and plug to change in size more than the other and thereby change said gap to a second volume different from said first volume and compress the body between said mold and plug into the molded product, wherein the change in the volume of the gap is caused essentially only by the change in temperature; anda plurality of pins circumferentially spaced apart and extending in a transverse direction relative to said central longitudinal axis so as to fixture said mold to said plug such that said mold and plug are allowed to undergo relative expansion and contraction toward and away from one another by said pins extending through and across a portion of said gap between said mold and plug at the locations of said pins when said mold and plug are at said first temperature and permitting the size of said gap at said locations of said pins to change as said mold and plug are changed from said first temperature to said second temperature.