Apparatus for controlling resistance to extrusion of a rod-like body through a die

DETAILED DESCRIPTION I claim: 1.
In an apparatus for the extrusion of a cohesive, continuous, rod-like coal-containing body wherein an extruder screw is disposed within extruder barrel construction, which in turn is connected to feed and discharge structures spaced from each other, said feed structure being means for feeding a mixture containing powdered coal and a binder into said barrel construction and said discharge structure being die means for receiving and shaping the mixture forcibly discharged from said barrel construction, means being provided adjacent said barrel construction for heating at least a portion thereof, means positioned downstream of said die means for severing the emerging rod-like body into smaller portions and means connected to said screw for driving said screw, the improvement comprising: a.
said die means being open-ended and of substantially constant cylindrical configuration internally, the wall of said die means having a plurality of spaced apart movable portions thereof adapted for inward displacement to selectively change the degree of discontinuity of the inner surface of said wall for contact with the mixture in transit therethrough, and b.
means engaging each of said movable wall portions for controllably varying the force with which said movable wall portions may be displaced inwardly, said force varying means including means for the automatic actuation thereof as a function of the force exerted by the means for driving the extruder screw.
2.
The improvement of claim 1 wherein the movable wall portions are pivotally connected to the wall of the die means.
3.
The improved apparatus of claim 1 wherein an electric motor is employed to drive the extruder screw and the force varying means comprise hydraulically-actuated biasing means contacting the movable wall portions, means electrically connected to said motor for sensing the current draw thereof, hydraulic fluid supply means in flow communication with said biasing means in a hyraulic circuit and means electrically connected to said sensing means and connected in said hydraulic circuit for varying the pressure of the hydraulic fluid in said hydraulic circuit