COTTON-SPINNING 975 



raised from the fluted segment and ceases to revolve. From the calleuder rollers, the 

 combed cotton passes along the front plate or conductor, where it joins the slivers 

 from the other five heads of the machine, and with them passes through the drawing 

 head, and is then deposited in a can ready to be removed to the drawing frame. 



Such is a minute analysis of the movements of this complicated piece of mechanism. 

 Perhaps a clearer and more complete view of its operation may be gathered from a 

 summary statement. 



The lap of cotton having been placed on a pair of revolving lap rollers, the fleece, 

 or sheet of cotton, is conducted down an inclined guide to a fluted steel feeding roller, 

 which places the cotton between the open jaws of an iron nipper. The nipper is then 

 closed and made to approach the comb cylinder, where it holds the fibres in such a 

 position that the combs of the revolving cylinder pass between and remove from the 

 fibres all impurities and short or broken cotton, which are afterwards worked up into 

 yarns of a coarser quality. As soon as the combs have all passed through the first 

 portion of the fleece under treatment, the nipper recedes from the cylinder, and when 

 it has reached the. proper distance, opens its jaws, and allows the partially combed fibres 

 to be drawn out of the fleece, by means of a leather-covered roller. The drawing out 

 of these fibres brings their uncombed ends, which were before held in the nipper, 

 under the teeth of a fine top comb, thus completing the combing of each separate fibre. 

 Previous to the movement for drawing out fresh fibres from the uncombed fleece, the 

 detaching roller has made a partial revolution backwards, and taken with it the combed 

 cotton previously delivered, in order to piece to it the fibres just combed. The machine 

 is so arranged that the forward movement of the detaching roller brings out the 

 cotton in a continuous sliver to the front of the machine. 



Both the detailed and the summary statement just presented describe only one 

 ' head ' or section of the machine. There are, however, working simultaneously side 

 by side and identical in construction, six heads on one machine. Each of these 

 delivers a continuous sliver of combed cotton, and the whole six slivers are finally 

 combined into one, which is then ready for the next operation, viz., Drawing. 



When the cotton leaves the carding engine (or in the case of very fine yarn the 

 combing machine) it ought to be quite clean, having regard to the particular degree of 

 purity and brightness required in the kind of yarn it is proposed to spin. If the dirt 

 and other impurities have not been sufficiently got rid of at this stage, there is no 

 hope of their being extracted afterwards. What remains now to be done before the 

 actual spinning can take place is simply to equalise the sliver and complete the 

 straightening of the fibres. To a great extent this last operation has been already 

 accomplished by the carding engine ; but a slight examination of the fleece as it comes 

 from the doffer of the engine will show that the parallelism of the fibres is as yet in a 

 very imperfect state. This double object of equalising the sliver and making the 

 fibres quite parallel and straight, is effected by means of the Drawing Frame. Tho 

 former end is reached by frequent combination of the sliver, by doubling as it is termed 

 whilst the latter is accomplished by drawing out or attenuating the combined slivers. 

 Tho drawing operation, or draught, is indeed repeated in all the subsequent processes 

 also, and it will therefore be convenient to describe it once for all. 

 Let a and b, fig. 559, represent the section of two rollers lying 



over each other, which touch with a regulated pressure, and turn "59 f 



in contact upon their axes in the direction shown by the arrows. 

 These rollers will lay hold of the fleecy riband presented to them 

 at the point of contact, draw it through between them, and 

 deliver it quite unchanged. The length of the piece passed 

 through in a given time will be equal to the circumference of one 

 of the rollers multiplied by the number of its entire revolutions 

 in the same time. Now if the speed and circumference of the 

 three sets of rollers shown in the figure be the same, that is 

 to say, if their surfaces travel at the same rate, the riband will 

 be delivered from the last pair of rollers of exactly the same 

 thickness or ' counts ' as at its entrance at the first pair. But if the surface speed of c 

 and d be greater than that of a and b, then the former pair will deliver a greater 

 length of riband than the latter receives and transmits to it. The consequence can 

 be nothing else in these circumstances than a regulated drawing or elongation 

 of the riband in the interval betwixt a, b, and c, d, and a tendency of the fila- 

 ments as they glide over each other, to assume a straight parallel direction. In like 

 manner the drawing may be repeated by giving the rollers e,f, a greater surface 

 speed than that of the rollers c and d. This increase of velocity may bo produced, 

 either by enlarging the diameter, or by increasing the number of turns in the same 

 time, or finally by both methods conjoined. In general the rollers are so adjusted, 



