Control apparatus for plastic blending machinery
First Claim
1. Apparatus for controlling the flow of fluent material from a material supply to a receiver, said apparatus comprising a generally vertical delivery tube having a discharge orifice at its lower end;
- a valve underlying said orifice and being of such area as to provide support for said material at its angle of repose and to close said orifice;
means mounting said valve for substantially vertical movements toward and away from said orifice, said valve being movable from a fully open position in which a clearance exists between said orifice and material supported at its angle of repose on said valve through which material may flow into said receiver and a closed position in which said orifice is closed;
sensing means coupled to said receiver for sensing an increase in the quantity of material in said receiver; and
operating means coupled to said sensing means operable in response to the sensing of a predetermined increase in the quantity of material in said receiver to move said valve from said fully open position to an intermeidate open positoin between said fully open position and said closed position and reduce said clearance, thereby reducing the rate of flow of material through said clearance to said receiver, said operating means also being operable in response to the sensing of a further predetermined increase in the quantity of material in said receiver to move said valve from said intermediate position to said closed position.
6 Assignments
0 Petitions
Accused Products
Abstract
Apparatus for controlling the discharge of fluent, particulate plastic material from a supply to a blending hopper comprises a delivery tube having a discharge orifice at its lower end that may be closed by a circular valve which seats against the delivery tube to close and seal the orifice. The valve is movable from its closed position to a fully open position in which a relatively large clearance exists between the discharge orifice and a body of material supported at its angle of repose on the valve. Material thus is able to cascade through the clearance to a receiving hopper whose weight is monitored by one or more load cells coupled to a microprocessor. When the weight of the receiving hopper increases to a selected value due to the delivery of material thereto, the valve is moved from its fully open position to a partially open position in which the aforementioned clearance is reduced substantially, thereby materially slowing the rate of discharge of material from the supply. When a predetermined quantity of material has been delivered to the receiving hopper, the valve is returned to is fully closed position, thereby terminating the discharge of material. The delivery tube has a chamber therein adjacent the discharge orifice that is devoid of material as long as material flows through the discharge orifice, and in which material supported atop the valve may be accommodated when the valve moves to its closed position.
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Citations
18 Claims
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1. Apparatus for controlling the flow of fluent material from a material supply to a receiver, said apparatus comprising a generally vertical delivery tube having a discharge orifice at its lower end;
- a valve underlying said orifice and being of such area as to provide support for said material at its angle of repose and to close said orifice;
means mounting said valve for substantially vertical movements toward and away from said orifice, said valve being movable from a fully open position in which a clearance exists between said orifice and material supported at its angle of repose on said valve through which material may flow into said receiver and a closed position in which said orifice is closed;
sensing means coupled to said receiver for sensing an increase in the quantity of material in said receiver; and
operating means coupled to said sensing means operable in response to the sensing of a predetermined increase in the quantity of material in said receiver to move said valve from said fully open position to an intermeidate open positoin between said fully open position and said closed position and reduce said clearance, thereby reducing the rate of flow of material through said clearance to said receiver, said operating means also being operable in response to the sensing of a further predetermined increase in the quantity of material in said receiver to move said valve from said intermediate position to said closed position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
- a valve underlying said orifice and being of such area as to provide support for said material at its angle of repose and to close said orifice;
- 17. Apparatus for controlling the flow of fluent, particulate material through a vertical tube having a discharge orifice at its lower end, said apparatus comprising a valve having a surface adapted to support material thereon at its angle of repose and to seat against said tube and close said discharge orifice and thereby prevent material from flowing therethrough, means for moving said valve upwardly to its closed position from an open position in which said valve surface is spaced below said discharge orifice, and a spout within said tube through which material flows into said tube, said spout having an outlet spaced inwardly from said tube and forming with the latter an annular chamber devoid of material when said valve is in said open position, said annular chamber being of sufficient capacity to accommodate material supported on said valve surface by permitting said material to expand into said annular chamber when said valve is moved from its open position to its closed position, thereby facilitating closing of said valve and preventing jamming or packing of said material in said discharge orifice.
Specification