Sealing closure for asphalt mix storage bin outlet

Claim 1

A sealing closure for a bottom outlet in a bin for storage of asphalt paving mix, said closure comprising: A. an annular rim member on the bin, surrounding said outlet, said rim member having coplanar downwardly facing radially inner and radially outer bottom surfaces extending therearound that are separated from one another by a downwardly opening groove extending around the rim member; B. a gate member having a flat top surface engageable with said bottom surfaces on the rim member; C. mounting means supporting the gate member with its top surface substantially parallel to the plane of said bottom surfaces on the rim member and for motion of the gate member in opposite closing and opening directions substantially parallel to its top surface, toward and from an open position in which the gate member is at one side of said outlet; D. actuating means for moving the gate member in said directions; E. cooperating motion translating means on the mounting means and on the gate member for imparting to the gate member an upward component of motion during a final portion of movement of the gate member in its closing direction, to bring the gate member to a closed position in which it extends across the outlet and in which its top surface is urged towards firm engagement with said bottom surfaces on the rim member; and F. means for forcing grease under pressure into said groove, at spaced locations around the groove, so that when the gate member is in its closed position the groove can distribute such grease all around the outlet and into any space between the top surface of the gate member and said bottom surfaces on the rim member, where the grease provides a seal around the outlet.