Patent ID: 7174758

Claim:
Device for measuring a roll gap ( 7 ) between work rolls ( 1 a ; 1 b ) of a cold or hot rolling stand for rolling out narrow or wide metal strip by means of roll gap sensors in the form of measuring probes, displacement sensors ( 6 ), electrohydraulic converters, magnetostrictive transducers ( 8 a ) whose signal can be transmitted as a roll gap set point to servovalves of a hydraulic oil control for piston-cylinder units that control the roll gap ( 7 ), wherein the position or displacement sensor ( 6 ) is installed close to the roll gap ( 7 ) in at least one bending cylinder ( 5 a ; 5 b ) for the work rolls ( 1 a , 1 b ) for indirect reference measurement of the roll gap via the positively or negatively acting bending cylinders ( 5 a ; 5 b ) to counteract lateral strip progression and wherein the position or displacement sensor ( 6 ) penetrates a cylinder liner ( 8 ), on whose end face a magnet ( 9 ) for a sensor rod ( 10 ) of the magnetostrictive transducer ( 8 a ) is mounted in a centric cavity ( 11 a ) of the piston ( 11 ) for the bending cylinder ( 5 ), and the sensor rod ( 10 ), which penetrates the piston rod ( 11 b ) of the bending cylinder ( 5 ), runs in an axial central bore ( 12 ) of the piston rod ( 11 b ), which ends at a vent hole ( 13 ).