Metering device for pressure feed containers, especially for metallurgical purposes

Claim 1

IN COMBINATION: A GAS TIGHT CONTAINER ADAPTED TO RECEIVE PULVEROUS MATERIAL, A GAS PERMEABLE MEMBER IN THE CONTAINER SPACED UPWARDLY FROM THE CONTAINER BOTTOM AND DIVIDING THE CONTAINER INTO AN UPPER CHAMBER IN WHICH THE PULVEROUS MATERIAL IS RECEIVED TO REST ON SAID MEMBER AND A LOWER CHAMBER TO WHICH GAS UNDER PRESSURE IS SUPPLIED TO FLOW UPWARDLY THROUGH SAID MEMBER AND MAINTAIN SAID PULVEROUS MATERIAL IN A FREE FLOWING STATE, A DISCHARGE PIPE IN THE CONTAINER HAVING ITS OWER END AXIALLY SPACED FROM SAID MEMBER AND LEADING VERTICALLY UPWARDLY IN SAID CONTAINER AND PASSING TO THE OUTSIDE OF SAID CONTAINER AND ADAPTED FOR THE DISCHARGE OF GAS AND PULVEROUS MATERIAL FROM SAID CONTAINER, A CONTROL PIPE VERTICALLY MOVEABLE IN THE CONTAINER AND SURROUNDING SAID DISCHARGE PIPE IN RADIALLY SPACED RELATION TO ESTABLISH AN ANNULAR PASSAGE BETWEEN SAID PIPES LEADING BETWEEN THE UPPER END OF SAID CONTROL PIPE AND THE LOWER END OF SAID DISCHARGE PIPE, SAID CONTROL PIPE EXTENDING TO NEAR THE TOP OF THE CONTAINER AND HAVING ITS UPPER END OPEN TO CONTINUOUSLY EXPOSED TO THE INSIDE OF THE CONTAINER TO RECEIVE GAS FROM THE CONTAINER FROM THE SPACE THEREIN ABOVE THE UPPER LEVEL OF THE PULVEROUS MATERIAL IN THE CONTAINER, MEANS CARRIED BY SAID CONTROL PIPE ADAPTED WHEN THE CONTROL PIPE IS MOVED TO A FIRST UPPERMOST POSITION ONLY IN THE CONTAINER TO CLOSE OFF SAID PASSAGE WHILE LEAVING THE LOWER END OF SAID DISCHARGE PIPE OPEN, SAID CONTROL PIPE OPERATIVELY SEALING ENGAGING SAID MEMBER WHEN SAID CONTROL PIPE IS MOVED TO A SECOND LOWERMOST POSITION ONLY AND THEREBY CLOSING OFF THE SUPPLY OF PULVEROUS MATERIAL FROM THE CONTAINER TO THE LOWERR END OF SAID DISCHARGE PIPE WHILE MAINTAINING SAID PASSAGE TO THE LOWER END OF SAID DISCHARGE PIPE, AND CONTROL MEANS CONNECTED TO SAID CONTROL PIPE FOR MOVING SAID CONTROL PIPE BETWEEN ITS SAID FIRST AND SECOND POSITIONS AND INTO ANY OF A PLURALITY OF POSITIONS INTERMEDIATE SAID FIRST AND SECOND POSITIONS, SAID CONTROL MEANS INCLUDING ACTUATING MEANS DISPOSED OUTSIDE THE CONTAINER.