AN APPLIANCE FOR THE WITHDRAWAL OF EXTRUDED MATERIAL ISSUING FROM EXTRUSION PRESSES

摘要

1,208,321. Extruder haul-off or withdrawal devices. SCHLOEMANN A.G. 30 Jan., 1968 [15 Feb., 1967], No. 4690/68. Heading B5A. [Also in Division B3] A withdrawing device C, D for the extruded product W leaving an extrusion press P has a speed regulating circuit K, Fig. 2, and a pull regulating circuit L which are brought into operation alternately by a change-over switch G. An extrusion gripper D is mounted on a carriage C driven through a cable 28, pulley 19, coupling 18, Fig. 2, and gearing 17 by an hydraulic driving motor 3. This is supplied by a variable delivery pump 10 driven by a motor 9 and whose output is controlled by a piston 8 supplied with control liquid through a regulating valve 5 by a control pump 7 driven by motor 6. A filling pump 12 is provided for the hydraulic circuit together with safety valves 11, 16, 16a. Carriage motor 3 drives a tacho-generator 4 whose output is compared in a bridge circuit K with a desired speed value set by a potentiometer 1. The output voltage of the bridge circuit is fed through contacts g 1 and f to a plunger coil 2 controlling the regulating valve 5 and hence the output of the pump 10. The hydraulic supply pressure to motor 3, which is a measure of the withdrawal pull, is detected by a gauge 22 and potentiometer 23 and is compared in a bridge circuit L with a desired pull value set by potentiometer 24. The output of this bridge circuit is alternately fed to coil 2 through contacts g 2 . Contacts g 1 and g 2 are switched alternately by a switch G controlled by a timer E which is started automatically and the contact f is closed by the leading end of the extruded product W interrupting a light beam between source A and a photo-cell B.