Sheet plastic article polishing apparatus

Claim 1

Apparatus for polishing the back-to-back surfaces of relatively flat plastic sheet-like articles having a relatively thin cross-section dimension between said back-to-back surfaces, said apparatus comprising: first and second rotatable endless belts, each belt having an inside surface and an outside surface, said first and second belts being arranged relative to each other such that substantial portions of their outside surfaces are in contacting face-to-face relationship, said outside surfaces of each belt having a high gloss, mirror-like finish, each belt being made of flexible metallic material which is adapted for retaining heat at a relatively high temperature for a controllable period of time; a first pair of longitudinally spaced-apart rolls mounted within said first belt and in contact with said inside surface thereof, one roll of said first pair of rolls being adapted for being rotatably driven so as to rotate said first belt and thereby rotatably drive the other roll of said first pair of rolls, said other roll of said first pair of rolls having an enclosed chamber therein; a second pair of longitudinally spaced-apart rolls mounted within said second belt and in contact with said inside surface thereof, one roll of said second pair of rolls being adapted for being rotatably driven so as to rotate said second belt and thereby rotatably drive the other roll of said second pair of rolls, said other roll of said second pair of rolls having an enclosed chamber therein, said one rolls, of said first and second pair of rolls being situated adjacent each other and said other rolls of said first and second pair of rolls being situated adjacent each other; first means for rotatably driving said one rolls of said first and second pairs of rolls whereby said first and second endless belts as well as said other rolls of said first and second pairs of rolls are rotated synchronously so that said contacting face-to-face outside surfaces of said first and second belts move at substantially the same linear speeds in the same direction, said same direction being iN a direction from said adjacent other rolls toward said adjacent one rolls; second means for delivering a heated fluid to said enclosed chambers of said other rolls of said first and second pair of rolls so as to enable transfer of heat from said fluid and other rolls to said first and second endless belts thereby elevating the temperatures of said belts to a relatively high temperature; first and second squeeze rollers situated within said first and second endless belts, respectively, and adjacent said other rolls of said first and second pair of rolls, said first and second squeeze rollers being in pressure contact with the inside surfaces of said belts so as to force the outside surfaces of said belts into face-to-face contacting relationship; a stationary arcuate member situated within said first endless belt and contacting the inside surface of said first endless belt so as to force the face-to-face contacting outside surfaces of said first and second belts to follow an arcuate path as said first and second belts move in the aforesaid same direction; and, third means adapted for retaining a heat quenching liquid, said third means being located with respect to said arcuate member and said face-to-face contacting outside surfaces of said belts such that said belts move in an arcuate path through said third means and are contacted by the heat quenching liquid.