Variable length extrusion die

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 operatively associated with said screw for driving said screw, the improvement comprising: (a) said die means being of substantially constant cylindrical configuration internally with the downstream end thereof remaining open throughout the extrusion operation and (b) means for controllably infinitely varying within a preselected range the extent of internal surface area of said die means available for contact with the consolidating coal-containing mixture, said die means retaining a substantially cylindrical configuration and said varying means being connected to an element in the group of elements consisting of said die means and said extruder screw whereby relative movement between said die means and said extruder screw is provided.