GB1273130A - Method and device for producing rubber profiles - Google Patents

Abstract

1,273,130. Controlling extrudate take-up speed. G. M. EGGER. 6 June, 1970, No. 27488/70. Heading B5A. [Also in Division G3] A solid or sponge rubber profile is extruded from a nozzle and conducted through a bath of heating liquid for vulcanization thereof which is provided with vacuum means 11 for removing gases, the liquid having a specific gravity in the order of that of rubber. At the exit of the treating vessel, the vulcanized profile passes over rollers to a unit for washing, drying, applying powder to the profile, and for winding it on to take-up reels. Automatic control is provided for continuous co-ordination of the extrusion speed and the exit speed whereby the cross-section of the profile is kept constant, and profiles of different size are produced by adjusting the speed-ratio. In one arrangement, the two speeds are detected by respective D.C. tachometer generators whose signals are compared in an amplifier which supplies the field winding of a motor driving an exit roller. The signal derived from the tachometer generator which is driven by the exit roller is generally reduced by a potentiometer before application to the ampliefier so that the exit speed is greater than the extrusion speed, Fig. 3 (not shown). In another embodiment, the tachometer generators 25, 26 are of the three-phase type connected to a phase indicator 27 which turns in a direction determined by the faster generator. Finger 28 engages contact 29 or 29<SP>1</SP> associated with field windings 22, 22<SP>1</SP> of motor 20. The latter drives the exit roller 17, and is coupled to the tachometer generator 26 through variable gear 33.