GB744743A - Improvements in or relating to apparatus for the continuous measurement of objects of great length - Google Patents

Abstract

744,743. Measuring continuous lengths of materials. HENLEY'S TELEGRAPH WORKS CO., Ltd., W. T., BRICE, P. J., and MACDONALD, H. A. Sept. 11, 1952 [Sept. 11, 1951], No. 21414/51. Class 42 (2). Apparatus for the continuous measuring of an object of great length drawn or forced through the apparatus by an outside force comprises an endless belt having a straight portion, means for maintaining the object during passage in contact with the said straight portion, a measuring wheel embraced over a substantial arc by the belt, and booster means operatively connected with the belt and arranged to provide a driving force sufficient to overcome the internal running resistance of the apparatus to movement of the belt. As shown, a cable 28 to be measured is drawn by a reeling device between vertical guide rollers 38 and over a horizontal portion 20 of an endless belt 17. The cable drives belt 17 with which it is kept in contact over portion 20 by the pressure of grooved idler rollers 27 in a housing 26. The inner surface of belt 17 is provided with teeth 18 which engage sprocket wheels 15, 16, a toothed measuring wheel 22 driving a counting mechanism 24, and a toothed jockey wheel 23. The belt is supported along portion 20 by idler sprocket rollers 21. Located in advance of belt 17 is a booster wheel 29 against which cable 28 is pressed by a roller 34 on a weighted arm 35. Wheel 29 is connected to wheel 22 by a chain 33 and sprockets 31, 32 and has a slightly smaller diameter than wheel 22 so that it rotates with a peripheral speed about 99 per cent of that of wheel 22. Alternatively, wheel 29 may be of the same diameter as wheel 22 and be positively geared thereto so as to rotate with a slightly lower peripheral speed. Wheel 29 is slightly tapered so that by relative lateral adjustment between the wheel and the cable the effective diameter and peripheral speed of the wheel can be varied. Since belt 17, and hence also the periphery of wheel 22, move at the speed of the cable, there will be a slight slip between the cable and wheel 29; the cable thus exercises a driving effect on wheel 29 which is transmitted to wheel 22 and is such as to neutralize internal frictional losses of the measuring wheel and belt assembly and thereby minimize slip between the cable 28 and the belt 17. The braking effect of wheel 22 on the cable keeps the latter taut during measurement. In an alternative embodiment the measuring wheel is located at one end of the horizontal portion of the belt which is arranged to embrace the measuring wheel over an arc of about 180 degrees. The booster wheel 29 and its associated parts may be replaced by a constant-torque electric motor driving the measuring wheel, the torque provided by the motor being arranged to be such as to overcome the internal frictional resistance of the measuring wheel and belt assembly.