Patent GB-858668-A (GB)
Title: Apparatus for regulating the contact pressure of pressure rolls in impregnating machines
IPC: C14C15/00
Filed: 1957-03-20
Abstract: <PICT:0858668/IV (c)/1> <PICT:0858668/IV (c)/2> <PICT:0858668/IV (c)/3> <PICT:0858668/IV (c)/4> An impregnating machine comprises driving means to feed material which is to be impregnated at a pre-selected variable speed, a pair of pressure rolls associated with means to regulate the contact pressure between the rolls and means operable to actuate the pressure regulating means such that pressure on the material passing therebetween is commensurate with the speed of the material.  As shown in Fig. 1 material W to be treated which may for example be a paper or textile web may be fed from a beam 1 over roll 2 so as to pass between pressure rolls 3, 3a before entering a drying chamber 5 and being wound up on roll 7. Conveyer rolls 6 may be driven by a transmission system comprising a variable gear 8 and motor 9 as also may be the pressure rolls 3, 3a.  The transmission system may consist of two pairs of coned half pulleys 8a, 8b around which a V-belt 8c passes.  A shaft 10 having two oppositely threaded portions is rotatable by an adjusting motor 31, the threaded portions of the shaft causing the halves of the upper pulley to be either brought closer together or moved apart from one another.  Connected to the speed adjusting shaft 10 is a regulating gear 11 comprising two conical rollers with an interposed friction disc, the transmission ratio of the gear being adjustable by a hand wheel 12.  The driven shaft may transmit its movement-to a rotary field transmitter 13, which is connected to a receiver 16 through leads 14, 15.  The p  electrical transmission system consisting of the rotary field transmitter 13 and receiver 16 is analogous to a three-phase motor driven by a three-phase generator.  When transmitter 13 is stationary no voltage is transmitted through the lines 14 to receiver 16.  When motor 31 is switched on for adjusting the gear 8, the rotary field transmitter 13 receives through gear 11 a rotary movement which produces an electrical rotary or three-phase current.  Owing to this 3-phase current in lines 14 the receiver 16 is adjusted like a motor.  The adjusting movement continues exactly as long as transmitter 13 is driven.  Transmitter and receiver are absolutely synchronised and even small changes in position at the armature of the transmitter cause correspondingly small changes in position at the armature of receiver 16.  Rotary field receiver 16 is disposed on a device 17 for adjusting the contact pressure between rolls 3, 3a.  When the axis of the rotary field receiver 16 is turned, it transmits its rotary movement through a worm 18 (see Fig. 4) to a toothed quadrant 19, which is connected to an indicator 20 (see Figs. 2, 3) and a contact carrier 20a for normal drive conditions.  Switch 21, co-operating with cam disc 22 which is fastened to axis 23 of indicator 24, is moved and adjustment shown by means of indicator 25.  If the speed of material W is varied, the variation is transmitted through gear 8, shaft 10 and gear 11 through leads 14, 15 to indicator 20. Switch 21 is displaced and in co-operation with a reversing relay (not shown) and pressure adjusting motor 30 another working pressure is produced which corresponds to the different speed.