Apparatus for the manufacture of hollow plastic articles

Claim 1

APPARATUS FOT THE MANFACTURE OF A HOLLOW ARTIC FROM THERMOPLASTIC SHEET MATERIAL COMPSIRING A PAIR OF OPPOSED FORMING TOOLS EACH FROMED WITH AT LEAST ONE CAVITYY OPPOSED TO A CORRESPONDING CAVITY IN THE OTHER FORMING TOOL, MEANS ASSOCIATED WITH THE FORMING TOOLS FOR MOVING THEM INTO AND OUT OF ACCURATELY-POSITIONED CONTACT WITH ONE ANOTHER, SO THAT THE OPPOSED CAVITIES IN ASSOCIATION CONSITUTE A COMPLETELY ENCLOSED HOLLOW ARTICLE-FORMING CAVITY OR CAVITIES, A P OUT OF A POSITION WHEREIN IT IS LOCATED BETWEEN THE FORMING TOOLS WHEN THE FORMING TOOLS ARE OUT OF CONTACT WITH ONE ANOTHER, MEANS FOR MOVING SAID PLATEN INTO AND OUT OF SAID POSITIONS, THE PLATEN HAVING OPPOSITE SURFACES FOR ENGAING THERMOPLASTIC SHEETS FROM WHICH THE ARTICLE IS TO BE FORMED, A HEATER HAVING A HEATING SURFACE AND MOVABLE INTO AND OUT OF A POSITION WITH SAID HEATING SURFACE OPPSITE ONE OF SAID OPPOSITE SURFACES OF SAID PLATEN, A SECOND HEATER HAVING A HEATING SURFACE AND MOVABLE INTO AND OUT OF A POSITION WITH ITS HEATING SURFACE OPPOSITE THE OTHER OF SAID OPPOSITE SURFACES OF SAID PLATEN, MEANS FOR MOVING SAID HEATERS INTO AND OUT OF SAID POSITIONS, AND MEANS COMPRISIN G AT LEAST ONE FLUID CONDUCTOR TO PROVIDE A PRESSURE DIFFERENTIAL ON OPPOSITE SIDES OF SHEETS IN ENGAGEMENT WITH THE PLATEN TO CAUSE THE SHEETS TO BE MOVED INTO FORMING CONTACT WITH THE CAVITIES.