Hopper structure

Claim 1

A BOTTOM OUTLET STRUCTURE FOR SELECTIVELY DISCHARGING FINELY-DIVIDED MATERIAL EITHER BY GRAVITY OR PNEUMATICALLY AND ADAPTED TO BE SECURED BENEATH THE BOTTOM OUTLET OF A HOPPER STRUCTURE COMPRISING, A GATE SLIDABLE IN OPPOSITE DIRECTIONS BETWEEN OPEN AND CLOSED POSITIONS RELATIVE TO THE BOTTOM OUTLET, A HOUSING INCLUDING A SUPPORTING FRAME BENEATH THE GATE ON WHICH THE GATE IS SUPPORTED FOR SLIDING MOVEMENT, A BOTTOM COVER BENEATH THE GATE FORMING WITH THE FRAME AND GATE AN ENCLOSED SPACE IN CLOSED POSITION OF THE GATE INTO WHICH MATERIAL FLOWS UPON OPENING OF THE GATE, A PNEUMATIC DISCHARGE CONDUIT COMMUNICATING WITH THE ENCLOSED SPACE BENEATH THE GATE FOR REMOVING PNEUMATICALLY THE FINELY-DIVIDED MATERIAL FROM THE AREA BETWEEN THE GATE AND COVER, SAID BOTTOM COVER CARRYING AN UPPER GAS PERMEABLE MEMBER SPACED FROM THE COVER TO FORM A PLENUM CHAMBER THEREBETWEEN WHEREBY AIR MAY FLOW FROM THE PLENUM CHAMBER THROUGH THE GAS PERMEABLE MEMBER TO AERATE THE FINELY-DIVIDED MATERIAL ADJACENT THE UPPER SURFACE OF THE GAS PERMEABLE MEMBER, AND MEANS FORMING A CONNECTION BETWEEN SAID HOUSING AND SAID COVER FOR WHOLLY SUPPORTING SAID COVER FROM SAID HOUSING, SAID MEANS BEING RELEASABLE TO PERMIT MOVEMENT OF SAID BOTTOM COVER FROM BENEATH THE GRAVITY GATE FOR ALLOWING A GRAVITY DISCHARGE OF MATERIAL UPON OPENING OF THE GATE.