GB635172A - Improvements in or relating to machines for classifying tubes, rods and the like according to weight - Google Patents

Abstract

635,172. Weighing-apparatus. HEWSON, MANUFACTURING CO., Ltd., and OYSTON, W. R. Nov. 6, 1947, No. 29638. [Class 143] In apparatus for classifying glass tubes or similar stock, the individual tubes are weighed and their length measured, and the weighing means is compensated according to the length measurement so that classification is according to the weight per unit length. The apparatus shown has its weighing range manually preset according to the nominal cross-section of a batch of tubes to be classified. The batch is laid across fixed projecting arms 11, 12 and the individual tubes are picked up in turn by star-wheels 14, 15 and dropped, first on to, arms 18 projecting from a pair of oscillating levers 16, 16a where their lengths are measured and the balance beam adjusted accordingly, and then on to recesses 34 in a pair of weighing levers 32, 33. A rearward arm 37 of the weighing levers is connected by a cable 38 and strip 39 to the balance beam 40. The counterweight is a roller 43 which is carried by an arm 44 pivoted to a block 45 and adapted to travel a short distance along the beam as the beam lifts during weighing so as to establish a balance. The weighing levers thus move downwardly by an amount dependent upon the weight of each tube to bring them opposite the appropriate one of a series of superposed discharge shoots 22, Fig. 4. To compensate the weighing mechanism for tube length, the block 45 (Fig. 5) supporting the arm 44 of the counterweight'43 is carried in a frame 47, 48 traversible lengthwise of the beam under the control of a length measuring arm 77 carrying a pad 78 which is brought into contact with an end of the tube whilst on the arms 18. The counterweight roller 43 is thus moved along the beam to a position dependent on the tube length immediately prior to the weighing of a tube. A further adjustment of the roller 43 can be made manually for presetting the weighing range for which purpose the block 45 is slidable lengthwise of the frame 47, 48 and locked relatively thereto in five alternative positions by a finger catch 63. This adjustment is accompanied by an appropriate adjustment of the lever ratio between the length measuring arm 77 and the frame 47, 48 so that length compensation of the counterweight remains accurate in all five positions. The apparatus functions continuously under the action of a pair of motor-driven cams 27, 28. In operation, the cam 28 first moves the levers 16, 16a rearwardly sufficient for a ratchet arm (not shown) on the shaft 17 of the levers to turn the star-wheels 14, 15 clockwise (Fig. 4) to deposit a tube on to the arms 18 and against a fixed stop 100. At the same time, a follower 75 of cam 27 rocks a vertical shaft 68 clockwise (Fig. 2) to swing the length measuring arm 77 into contact with the tube end (the other end being held) in which position the arm is held, during weighing, by a pawl 82 brought up to a ratchet quadrant 81 on shaft 68 by the movement of the lever 16a. When the levers 16, 16a reach their rearmost position under the action of cam 28, their arms 18 release the tube which then drops on to the weighing levers 33 which lower it to the shoot 22 appropriate to its weight per unit length. Finally,.as the cams 27, 28 return to their initial positions, the levers 16, 16a move forwardly and eject the tube from the weighing levers and into the shoot 22. The pawl 82 is released by this movement of lever 16a so that the length measuring arm 77, the frame 47, 48 and the counterweight 43 return to their normal positions under spring action and ready to deal with the next tube as a further revolution of the cams commences. The apparatus may be fitted with indicating mechanism to show the actual weights per unit length.