Investment mixer

Claim 1

VACUUM INVESTING APPARTUS, COMPIRISING: A BOWL ADAPTED TO HOLD A QUANTITY OF INVESTMENT MATERIAL TO BE MIXED AND OPEN AT ONE END; CLOSURE MEANS FOR SAID ONE OPEN END INCLUDING INVESTMENT DISCHARGE MEANS AND MEANS FOR CONNECTING TO A VACUUM LINE TO MAINTAIN THE INTERIOR OF THE APPARATUS UNDER A PARTIAL VACUUM; A FLASH POSITONED BY ENGAGEMENT WITH THE CLOSURE MEANS TO RECEIVE INVESTMENT MATERIAL FROM SAID DISCHARGE MEANS WHEN THE APPARATUS IS INVERTED; A FIXED INCOMPRESSIBLE SLEEVE PASSING THROUGH THE BOWL WALL AT A POSITION LOCATED AT THEBOTTOM OF THE BOWL WHEN MIXING IS CARRIED ON, SAID SLEEVE EXTENDING UPWARDLY INTO THE BOWL TO A LOCATION NEAR THE AVERAGE SURFACE LEVEL OF INVESTMENT MATERIAL IN THE BOWL DURING MIXING; A GENERALLY UPRIGHT RIGID SHAFT ROTATABLY MOUNTED IN THE SLEEVE AND PROJECTING BEYOND THE SLEEVE AT EACH END THEREOF, SAID SHAFT BEING ADAPTED AT ITS LOWER END FOR CONNECTION TO MEANS FOR ROTATING THE SHAFT; STIRRING ARM MEANS ON THE SHAFT AT THE UPPER END THEREOF; SAID SLEEVE AND SAID SHAFT HAVING COOPERATING MEANS PROVIDING A PAIR OF ENGAGING THRUST BEARING SURFACES LOCATED AT THE LOWER END OF THE SLEEVE OUTSIDE THE BOWL, SAID SURFACES RESISTING DISPLACEMENT OF THE SHAFT UPWARDLY RELATIVE TO THE BOWL BY FORCES DIRECTED AXIALLY THEREOF AND INWARDLY OF THE BOWL; AND FLUID SEALING MEANS BETWEEN THE SHAFT AND THE SLEEVE.