Fig. 162.J.N.
(314) It is, of course, highly essential that all the three releasing motions shall be accurately “timed,” so as not to take place either before or after the proper moment. Accordingly, ample means of adjustment are provided, both on the rod X by the regulation of the stops X1 and X2; on the connecting rod M coupling the levers Z and T; and also on the holding-out rod. In this way it is possible to secure that simultaneous movement of the three parts, which is so essential for effective working. It is obvious that the backing-off friction and holding-out catch must be released before the taking-in friction gears, but the interval between these is so slight that they occur practically simultaneously.
(315) The taking-in friction being in gear, the rotation of the loose pulley is, by the train of wheels shown, communicated to the “scroll” shaft, on which the taking-in scrolls are fixed. These have bands attached to and wrapped round them when the carriage is at the roller beam. As the carriage runs out, the bands, which are fastened to it, are drawn off the scrolls, the scroll shaft being then free to revolve. The engagement of the taking-in friction reverses this process and winds on the bands, thus drawing up the carriage. It will be observed that the scrolls vary in diameter, being about 9 inches in the largest part, and about 3 inches in the smallest. The reason of this construction is to give a varying traverse to the carriage, so as to start it easily, and bring it up to the back stops gently. The scrolls are designed so that, so long as they are revolving, they exercise a pull upon the carriage which is steady and constant. In this way, over-running is avoided, but to prevent any possibility of it a scroll L1, shown in a detached position in Fig. [153], is fixed on L at an angle of 180 degrees to the others, the point of attachment of its rope being diametrically opposite that on the other scrolls. Thus when the bands on the drawing out scrolls are unwound, that on the “check scroll” is wound and vice versa. The purpose of this scroll is, as its name indicates, to check any tendency to over-running, which it effectually does. In all mules above a certain length, it is desirable to provide some means whereby the carriage shall be drawn in evenly throughout its length, and shall not be in danger of twisting or warping. The scroll shaft, it will be noticed, only extends across the headstock, so that the bands can only exercise any pull on the square, and if no other points of attachment were made, the carriage would at its extremities lag behind the centre. A considerable amount of friction would be thus caused, and the spindles at the end of the carriage would not take up the full length of yarn. It was shown that the back shaft is, during winding, disengaged, so that it is only necessary to establish a connection between it and the scroll shaft, to enable the carriage to be drawn in at several points throughout its length, instead of at one only. Accordingly, the scroll shaft is extended, and an extra scroll shown in Fig. [154] at the right hand side is fitted, from which a band is taken to a drum upon the back shaft. Thus the back shaft is converted into a taking-in shaft, and during that operation revolves of necessity at a variable speed given to it by the scrolls. In this way the carriage is kept parallel to the roller beam throughout its course, and comes up to the back stops along its entire length at one time.
(316) The arrangements for taking-in having thus been described, it now becomes necessary to describe the operation of winding. Before doing so, it will be better to deal with the problem to be solved, and it will aid in understanding it if the construction and method of building the cop be described. For this purpose a reference to the diagrams given in Figs. [163] and [164], page 207, is necessary. The cop is built, as before explained, upon the blade or taper part of the spindle, and, when finished, is of the shape shown in Fig. [163], viz., a cylinder with conical ends. The central part of the cop, E G K F, is cylindrical, and at the top and bottom of this part are two cones. The lower cone, A E B C F D, forms what is known as the “cop bottom,” and the upper one, G H I K, the “nose,” although the latter term is more often and strictly applied to the extreme apex at the points H I. As previously stated, the yarn may be wound either upon the bare spindle, upon a short paper tube, as indicated by the thick line inside the cop bottom, or upon a similar tube the whole length of the cop. The use of paper tubes of this character is preferable, especially in cases where the cop is likely to be much handled, as it prevents it from being crushed in, and enables the introduction of a skewer for subsequent winding without there being any danger of the cop being pierced or “stabbed,” this being a fruitful source of waste.
(317) In commencing to wind, the yarn is wrapped on the lower part of the spindle in close coils or spirals for a length of a little more than an inch. The whole of one stretch is wrapped upon this space, and when the next stretch requires winding, it is laid upon the previous layer, and so on until the double cone A E B C F D is produced. The length of the traverse of the winding faller wire, or the length of each layer vertically, is called the “chase” of the cop or faller. From this point the yarn is wound in successive layers, beginning always at a higher point, until the final traverse is obtained by which the winding is conducted upon the surface or nose represented by the letters G H I K. It was stated in paragraph 311 that the winding faller wire, when the winding faller is locked, is in a position a little below the point H I. As soon as the carriage begins to run in, the vertical movement of the winding faller locking lever begins, and is so arranged that the first movement of the wire is a rapid downward one. The effect is that the yarn is laid on the nose of the cop in coarsely-pitched descending spirals, as shown in Fig. [164], these extending downwards until the winding faller wire reaches a point opposite the base of the upper cone, in this case shown in Fig. [163] at K. From this point a slower ascent of the winding faller wire is made, so that the yarn is laid in the more finely pitched spirals shown, until the nose of the cop is reached. By this time the carriage has arrived at the roller beam, and the whole of the 63 inches of yarn has been wound.
(318) When the first layer of yarn is wound, and the winding faller is assuming its position to wrap on the second, the initial point of its traverse is a little raised. In this way the yarn is gradually wound in layers, which are represented by the angular lines springing from the lines A E and D F towards the spindles. During this period the enlargement of the diameter of the cop bottom is proceeding until at the points E F the full diameter of the cop is reached. As soon as this occurs the initial point of each layer is gradually raised, and the length of the traverse is slowly diminished as the completion of building is approached, until at the termination of a cop the angle of the layers is shown by the lines G H and I K. There are thus two adjustments shown to be necessary—first, the starting point of each traverse of the winding faller requires altering; and second, its extent also needs regulation.
(319) These two objects are attained by the regulation of the copping rail P, as shown in Fig. [161]. The ends of this rail rest upon inclined “copping” plates Y X, which are fastened together by the rod W, and which receive, as will afterwards be described, an inward movement during the building of the cop. It was shown that the locking of the faller lever and its vertical movement leads to a corresponding movement of the faller. If, for instance, the faller locking lever fell an inch, the winding faller sector would be oscillated and the faller wire drawn upwards. The rate of the ascent of the latter is absolutely relative to the period of the descent of the locking lever. Referring now to Fig. [165], which is a small diagrammatic sketch of the copping rail and its supports, suppose the line G H to represent the top of former, O P the latter, and L the bowl at the foot of the locking lever, if L, starting from the left hand position, be supposed to travel in the direction of the arrow V, it will be seen that it will fall to the extent indicated by the space Y Z. If, on the other hand, the slides O P are moved into the position shown by the dotted lines, the rail G H will also fall into that indicated in a similar manner. The result is that if L now makes the same traverse as before it will rise a little as indicated by the space W X. The effect on the winding faller would be that in the first case it would be raised, and in the second it would be depressed to an extent corresponding to the depression of the locking lever. The extent to which this elevation or depression is made depends upon the vertical traverse of the locking lever, and the ratio of the distance of the point of junction of the sector C with the faller shaft and that of the faller wire from the same rod. If, for instance, this proportion was 1:2, an elevation of the locking lever half an inch would result in a depression of the faller an inch. It is therefore necessary, during the inward run of the carriage, to provide for the inclination of the carriage to such an extent as to secure the requisite traverse of the faller wire. As the amount of such traverse varies during the building of the cop, it follows that the inclination of the copping rail must be varied correspondingly.
Fig. 165.J.N.