GB1391029A - Arrangement for measuring the gap of a pair of rolls for a roll stand - Google Patents

Abstract

1391029 Rolling mills VEREINIGTE FLUGTECHNISCHE WERKE-FOKKER GmbH 18 May 1973 [20 May 1972] 23869/73 Heading B3M [Also in Division G1] The gap between two rolls of a rolling mill is measured by providing each roll with a projecting ring on one end, the ring co-operating with an inductive, capacitive, optical or electromechanical sensor to give a position signal. An inductive series 13 is shown in Fig. 2, and comprises an E core 14 carrying two coils L 1 , L 2 and positioned adjacent the ring 11 on the end of roll 10. The sensor is mounted movably on a housing 12, Fig. 3, attached to a fixed frame, and the further sensor 13<SP>1</SP> is likweise mounted to co-operate with the second roll. The housings 12, 12<SP>1</SP> contain electric stepping motors, Figs. 4a, 4b (not shown), geared to the sensors so that the latter can be moved along the vertical axis of Fig. 3. The four coils of the two sensors are connected to an oscillator 20, Fig. 6, via a transformer 21<SP>1</SP>; any displacement of the roll rings from the E cores results in the coils L 1 and L 2 becoming of different inductance which is detected at phase dependent rectifiers 25, 25<SP>1</SP> which give D.C. signals A, B representing the positions of each ring relative to its sensor. The apparatus is initially calibrated by bringing the rolls into contact without a workpiece. The stepping motors then move the sensors until the signals A and B are zero. The signal A-B is then fed to a roll gap controller and one or other of the sensors is moved by its motor through a distance equal to the desired gap, and the controller causes the corresponding roll to move a similar distance. The gap is now set and is maintained in subsequent use.