Method of and apparatus for controlling material flow

An apparatus for controlling material flow which includes a housing in which is formed a passage through which the material passes, and at least one door which is located in the passage, said door, when in a closed position, presenting a first surface subject to oncoming material flow through the passage, a control device connected to said door for moving said door, said door being movable by said control device to regulate the rate of material flow through the passage, said door being movable by the material flow, when the rate of material flow through the passage reaches a predetermined level, into a blocking position at which the said first surface is presented to outgoing material flow from the passage and at which the door at least substantially reduces the rate of material flow through the passage, wherein the control device includes a handle which is engaged with the door, the apparatus including means for disengaging the handle from the door when the door moves to a predetermined position.

An apparatus for controlling material flow, comprising a housing defining a flow passage having upper and lower walls and side walls on each side, said upper wall having a dome-shaped wall portion spaced from said inlet, a door in said housing having an axle pivotally supporting said door for rotation about a substantially horizontally axis and having an outer circumferentially extending wall spaced from said dome-shaped portion in all positions of its pivotal movement and having a first end which rest on said lower wall in a closed position in which it has an opposite second end spaced only slightly from said dome-shaped wall, said opposite second end resting on said lower wall in an opened position leaving a larger spacing of said first end from said upper wall, and entraining means carried on the interior of said door positined to entrain material and to bias said door in both an opened and closed position.