GB988791A - Improvements in and relating to electrical length measuring and control apparatus - Google Patents

Abstract

988,791. Measurement of length. ENGLISH ELECTRIC CO. Ltd. April 28, 1961 [Feb. 10, 1960], No. 4770/60. Heading G1M. The length of a bar 10 leaving a rolling mill is measured by a set of equally spaced photoelectric cells 14 and a further set of equally spaced photo-electric cells 15, whose total separation is the same as that between adjacent cells 14. The cells give a "material absent", or "material present" signal which is fed to a unit 16. When at least one cell 15 produces a "material present" signal and at least one cell 14 produces a "material absent" signal the unit 16 calculates the length of the rod. A more accurate measurement may be made by using a roller 22 engaged by the leading portion of the bar 10 to send a signal to the unit 16 depending on the position of the end of the bar between the cells 15. A computer 17 is fed with the measured length from the unit 16 and also with required piece lengths from a unit 18. The computer selects and shows on an indicator 21 the piece lengths which will leave the minimum wastage and the bar is cut by an operator using a hot saw 13. The operator can reset the computer to produce a new programme after some pieces have been cut if he notices that the length of deformed tail on the bar is different from that expected. If the bar 10 is larger than the separation of the outer cells 14, 15 the computer shows on the indicator the required piece lengths in the order fed into a storage unit for the computer, and these are cut off until the bar 10 is of measurable length.