Apparatus for sub-zero treatment of metals

Claim 1

A LID FOR SEALING THE TOP OF A VACUUM COOLING CHAMBER, AND A LID POSITIONING ASSEMBLY, SAID LID BEING CONSTITUTED BY A MAIN LID PORTION ADAPTED FOR ENGAGEMENT WITH THE TOP OF SAID CHAMBER AND BEING CONFIGURATED TO HAVE A PORT THEREIN, A CAP DISPOSED ABOVE SAID PORT AND BEING ADAPTED FOR VERTICAL MOVEMENT INTO AND OUT OF SEALED ENGAGEMENT WITH SAID PORT, AND A LIP SECURED TO SAID MAIN LID PORTION AND DISPOSED TO ENGAGE SAID CAP UPON UPWARD VERTICAL MOVEMENT, THEREOF, SAID LID POSITIONING ASSEMBLY COMPRISING AN ARM EXTENDING HORIZONTALLY OVER SAID LID, A LIFTING MEMBER IN COOPERATIVE ENGAGEMENT WITH SAID CAP, MEANS CARRIED BY SAID ARM FOR RECIPROCALLY MOVING SAID LIFTING MEMBER VERTICALLY, WHEREBY UPON UPWARD MOVEMENT OF SAID MEMBER SAID CAP IS INITIALLY DISENGAGED FROM SAID PORT RELEASING THE VACCUM WITHIN SAID CHAMBER, AND UPON FURTHER MOVEMENT OF SAID LIFTING MEMBER, THE CAP IS BROUGHT INTO ENGAGEMENT WITH SAID LIP, WHEREUPON STILL FURTHER MOVEMENT OF THE LIFTING MEMBER RESULTS IN THE MAIN LID PORTION BEING RAISED.