Joseph Nasmith

“ In brief, the essential consideration is a commercial one, and that machine is the best, and is used most skilfully, which effectually opens the matted cotton and shakes out the largest body of impurities with the least loss of fibre, either from its being driven out with the dirt or by breakage or rupture. Economy and efficiency are the watchwords of a good spinner, and nowhere is this combination more desirable than in the early stages of the manufacture. ”

“ It is without exception the most interesting of the whole series of machines used in cotton manufacture, combining an intricate sequence of mechanical movements with great ingenuity. As a further consideration will show, one piece or part of the mechanism used performs work widely diverse in its character at different periods, and it is this fact which renders the mule so difficult a machine to understand. The time occupied in completing the cycle of operations which constitute mule spinning is so small that the action of the various parts must be very rapid and certain. ”

“ The solidity of English machinery has been sometimes scoffed at by Continental and American rivals, but it would be difficult to find any which runs at higher velocities with greater steadiness and less repairs. It cannot be too often insisted on that the rigidity which arises from mere weight is by no means an unimportant quality. Of course, there are limits to this as to every other principle, but generally it is a true one. Of quite as much importance is the rigidity which comes from sound construction; and in this respect modern spinning machinery is remarkable. ”

“ The regularity of the pulsations of a scutcher beater is a matter requiring consideration. It is a subject not always thought of, but it has a great influence upon the resultant lap. The cotton—as will be hereafter shown—is struck from a roller or pedal, and is thrust into the range of action of the beater blades at a defined and regular rate. As it is desirable to beat it into small tufts before flinging it on to the grids, and as the cotton is liable to damage if the pieces struck off are too large, it follows that the oftener the blades strike the better. ”

“ The cotton fibre is a hollow tube of cellular construction, and is of an oval or flattened cylindrical shape. Ripe or fully matured fibres of the best cotton are convoluted or spirally twisted on their axis, and the edge of such a fibre presents a corrugated appearance. The regularity of the convolutions, or twists, is greatest in the highest class of cotton, and reaches its lowest point in the poorer grades. One important effect of such a formation is that each fibre naturally tends to coil round its neighbour, and thus lends itself to spinning. ”

“ Indian cotton is coarser, harsher, and not so clean as other varieties, and requires greater care in its manufacture. Summing up, the desirable points in cotton are the length and regular convolute form of the fibre, together with its freedom from mechanical and chemical impurities. The object of the earlier mechanical processes through which cotton passes is to remove all the impurities, lay the fibres regularly and in equal numbers alongside each other, without breaking or rupturing them, and without destroying their natural tendency to twist round each other. ”

“ In theory it is quite true that the periphery of a cylinder revolving, say, 180 times per minute, will tend to follow a path which is not an absolutely true circle. Further, the vibration set up in working, and the constant tendency from centrifugal action for the cylinder to roll forward, have a certain bearing on the subject. For these reasons there are some persons who contend that during the grinding of the cylinder teeth the cylinder should be run at its normal velocity, and the emery grinding roller be driven at a surface speed approximating to that of the cylinder. ”

“ In forming a cop, the diameter on which the yarn is wound is constantly changing, and the largest diameter is only a little smaller than the internal diameter of the ring, while the smallest will be about 3⁄16 of an inch. Now, it will be easily understood that the drag exercised by the yarn on the traveller will be greater when it is being wound on the larger diameter than when on the smaller, it being remembered that the spindle is always revolving at a regular rate, and consequently taking up more yarn per revolution on the body of the cop than on the spindle. ”

“ The whole of the worker and clearer rollers are covered by a case, as are also the doffer and licker-in. The emission of fly into the room is thus prevented, and its production materially diminished by the reduction of the disturbance of the air set up by the rapid rotation of the cylinder. The roller and clearer machine is often made with two cylinders, being then known as a “double” card. The cotton, after passing all the rollers placed above one cylinder, is transferred to the second by means of a small drum, similar in construction to a doffer, and known as a “tummer.” ”

“ Again, the pitch of the wire teeth upon the various flats can widely vary. Those at the feed end may be, and often are, much coarser than those at the delivery end, a proportionate gradation of pitch occurring throughout the whole series. It will be at once seen that the conditions prevailing in a revolving flat machine are entirely contrary to this practice. In that machine the setting of all the flats is devised so as to make them equidistant from the cylinder centre, and every flat must of necessity be covered with wire clothing of the same counts. ”

“ THE RING SPINNING MACHINE. (366) The term Ring Spinning is applied to that process by which yarn is spun by means of a machine in which a spindle, revolving in the centre of an annular ring, is used. The ring is formed with a flange or bead over which a C shaped clip or “traveller” is sprung, being drawn round the ring by the yarn during the revolution of the spindle. It is from the use of such a “ring” that the system has been named. The difference between mule and ring spinning is mainly that between continuous and intermittent work. ”

“ The lattice feed apron consists of a number of narrow strips of wood fixed to two endless bands passing round rollers at each end of a longitudinal frame fixed to the machine. By suitably driving one or both of the rollers a continuous motion is obtained, and the wood strips being each free from the other no difficulty is experienced in forming an endless apron or feed table. The cotton is placed upon the table in large pieces or lumps, just as these are taken from the bale, and they are carried forward until they come into contact with the first pair of rollers. ”

“ Everyone is aware of the tendency of a rapidly revolving body, such as a humming top a little out of balance, to assume such a position that its axis is out of the perpendicular while its revolution is going on with absolute steadiness. The high rate of speed which is attained with ring spindles, running up to 11,000 revolutions per minute, produced as might be expected, a certain amount of vibration which it is desirable to avoid. ”

“ On the other hand, the function of the counter faller being merely to maintain the tension of the yarn during winding and backing-off, it is necessary that it should be free, so as to bear constantly against the underside of the threads without exercising an undue strain. The pressure thus exerted should be a little in excess of the downward pull of the whole of the threads which are being spun in the machine, but not so much in excess as to prevent the counter faller yielding a little if from any cause an extra pull is put upon the threads. ”