« PreviousContinue »
yarn during reeling, the standard of tension being the weight of 1,000 yards of yarn of the various counts; the speed of reeling does not effect the degree of tension. The yarn to be reeled is passed through a guide eye A2, and round a conical drum. M covered with emery (see detail in upper portion of Figure 8), then again through the eye A2, and upwards to an eye mounted on a lever K which registers the amount of tension, then the thread is led downward and passed round the measuring drum, through two eyes W and Y and on to the reel. The degree of tension is governed by the position occupied by the yarn during its passage round the emery covered cone, and the amount of tension is recorded by the pointer at K shown on quadrant F2. This is a very ingenious and well-constructed machine, and suited to the requirements of accurate measuring; it is, however, rather costly, which will probably prevent its general adoption.
The plan adopted in the tests given in this paper was to pass the yarn amongst a number of glass rods, the number being determined by a series of measurements of the leas wrapped; the reel was rotated at as regular a speed as could be got by hand turning. As regards the determination of the exact length of material reeled, it was thought that if such a tension were put on the yarn that the lea when reeled would just enclose a template 4 yard long that a correct length would be ensured, and this is practically the plan adopted.
The device illustrated at Figure 9 is designed to measure and determine the length of yarn reeled by hanging the lea on a bar and suspending a weight on the lea by means of a hook which will show on a graduated scale any variation from 34 yard. The weight must be sufficient to straighten, but not to stretch the threads.
Weighing the Material. After the yarn has been measured it must be weighed and the count calculated. For accurate weighing nothing is better than a chemical balance and weights graded to grain. This plan, however, does not lend itself to the every day practice of a mill warehouse or office, hence a
YARN MEASURING DEVICE.
number of special balances have been designed to expedite this work.
Lea Quadrant.-Figure 10 shows a machine which is intended. to weigh and indicate on the quadrant the count from one to seven leas of cotton. If the machine is arranged for a small number of
leas, say three, then it is desirable when fine counts are being tested to take a double quantity of yarn, as the markings near the bottom of the scale are very close. This machine has its beam mounted on knife edges, the indicating line is very fine and is quite close to the face of the quadrant.
Knowles Balance.-Figure II is an illustration of the Knowles Yarn Assorting Balance. This is a more useful machine than the last, and can of course be used for other purposes than that for which it is primarily designed. Its most important feature is that it is a good balance. Behind the beam of the balance is placed an octagonal prism, on seven faces of which are engraved
are used, namely, a flat circular pan weight, and a rider weight, there are two weights for each face of the prism, and each is engraved with a letter corresponding to a letter on the face of the prism, and with a number representing the number of leas
being tested. The balance shown is arranged for testing one lea of yarn, but the weights are also arranged for other numbers of leas. The method of procedure is as follows: the reputed count being known the prism is turned until the face containing the count appears in front, one lea of yarn is placed in the right hand pan of the balance, and the properly lettered pan weight in the left hand pan, the rider weight bearing the same letter is now placed on the beam, and is moved along until it is opposite the reputed number of the yarn being weighed, a trial is made by raising the beam; if it fails to balance, the beam is lowered and the rider slid along to the right or left until the beam is eventually brought into equilibrium. The count may now be read off on the prism opposite an engraved line in the centre of the rider weight. This plan dispenses with all calculation and reference to tables. It is, of course, a machine which requires careful handling.
Brown & Sharpe's Balance. Figure 12 shows a view of a handy balance of another type and which is designed for weighing leas of yarn. It is made by Brown & Sharpe, the well known tool makers of Providence, R. I. The beam is graded to 20 grains with sub-divisions in grain. For general warehouse work it is a very satisfactory balance.
FIGURE 12.-BROWN & SHARPE YARN BALANCE.
Determination of Count.—When using balances that give only the weight and not the count, it is necessary to obtain the count either by calculation or by reference to tables specially prepared for the purpose.
This introduces the question as to the most suitable kind of weights to be used with an ordinary scale or balance. Some people still use the I oz., 1⁄2 oz., 4 oz. and dwt. and grain weights and this practice has been fostered by the use of one of the oldest and best known tables which gives the heavier weights in ozs. and dwts. Figure 13 shows a portion of this