Powder dispensing apparatus

Claim 1

IN APPARATUS FOR DISPENSING POWDERED MATERIALS FROM A HOPPER IN A STREAM OF CARRIER GAS, THE COMBINATION OF A POWDER HOPPER, A MIXING CHAMBER DIFINED BY A TOP WALL, SIDE WALLS, AND A DOWNWARDLY CONVERGENT BOTTOM WALL WITH A CENTRAL OUTLET OPENING, SAID TOP WALL HAVING A CENTRAL OPENING THEREIN IN COMMUNICATION WITH THE BOTTOM OPENING OF THE HOPPER AND ALSO HAVING AN INTERNAL ANNULAR MANIFOLD CHAMBER THEREIN, A BELL VALVE IN SAID MIXING CHAMBER, SAID BELL VALVE HAVING AN UPWARDLYPRESENTED AND UPWARDLY-CONVERGENT SURFACE, MEANS SLIDABLY MOUNTING SAID BELL VALVE FOR ADJUSTMENT OF SAID VALVE RELATIVE TO THE OPENING IN THE TOP WALL OF THE MIXING CHAMBER FOR CONTROLLING THE RATE OF POWDER FLOW THROUGH SAID OPENING, AND CONDUIT MEANS FOR SUPPLYING CARRIER GAS TO THE MANIFOLD CHAMBER WITHIN THE TOP WALL OF THE MIXING CHAMBER, SAID TOP WALL HAVING A RING OF DOWNWARDLY-INCLINED JET ORIFICES THEREIN DIRECTED AT SAID BELL VALVE, WHICH OPERATE TO INJECT CARRIER GAS FROM THE MANIFOLD CHAMBER TO SWEEP DOWNWARDLY OVER THE UPWARDLY-PRESENTED SURFACE OF THE BELL VALVE, AND AT LEAST ONE ADDITIONAL JET ORIFICE WHICH OPERATES TO INJECT CARRIER GAS THROUGH SAID BELL VALVE.