Method and apparatus for determining at any given moment what length of a continuous strip of material has passed a given point

摘要

PICT:1060971/C1/1 In the production of a continuous ribbon of glass on which one or more operations such as fault-detecting, scoring, breaking and labelling are to be carried out, there is provided apparatus for determining at any given moment what length of a moving strip of glass has passed a given stationary point of reference. This apparatus comprises a continuous measuring device, e.g. a wheel rolling on the strip of glass 1 and a calibrating device being intermittently compared with the information supplied by the continuous measuring device and the error found by this comparison is used to adjust the continuous measuring device. This is effected by feeding to a bevel gear 25, forming part of the transmission between a wheel 12 and an indicator 21, an angular correction for correcting the cumulative errors and by applying a speed correction for adjusting the transmission ratio of said transmission. The calibrating device may record equidistant marks on the strip, the distance between the marks corresponding to the length of a reference base fixed relative to a working position. Alternatively (see Fig. 1, not shown) a succession of lengths may be recorded on the strip by means of a moving member 7 intermittently locked with the strip.