PRODUCTION OF SLUBBING AND ROVING FRAMES IN LBS. PER WORKING WEEK OF 56 HOURS.
| Hank Roving. | Speed of Spindles. Revolutions Per Minute. | Twist per Inch. | Production. | Maker’s Name. |
|---|---|---|---|---|
| ·50 | 600 | ·85 | 114 | John Mason. |
| ·50 | 600 | ·85 | 116 | Crighton and Sons. |
| ·50 | 700 | ·84 | 115 | Howard and Bullough. |
| 1·00 | 700 | 1·20 | 56 | John Mason. |
| 1·00 | 700 | 1·20 | 56 | Crighton and Sons. |
| 1·00 | 700 | 1·20 | 59 | Howard and Bullough. |
| 3·00 | 1000 | 2·08 | 17 | John Mason. |
| 3·00 | 1000 | 2·08 | 16 | Crighton and Sons. |
| 3·00 | 1100 | 2·07 | 16·53 | Howard and Bullough. |
| 6·00 | 1400 | 2·94 | 7·25 | John Mason. |
| 6·00 | 1300 | 2·94 | 7·20 | Crighton and Sons. |
| 6·00 | 1100 | 2·92 | 6·25 | Howard and Bullough. |
Note.—The velocity of the spindles and amount of twist introduced will largely influence the productions as given above, which are only illustrative of the capacity of these machines.
CHAPTER XI.
THE MULE.
(264) The last process in the production of yarn is that in which the rovings, obtained in the manner described, are elongated and twisted into a thread. To many persons this is known as “spinning,” although strictly speaking, that phrase is applicable to the whole range of treatment by which cotton is converted into yarn. Using the term, however, in its narrower sense, spinning may be either an intermittent or continuous operation, that is, the rovings can be twisted for a portion of the time only during which the machine is working, or for the whole of that period. Although the latter system is the most ancient, for the last century the former has been more generally pursued. It is, therefore, advisable to describe first the machine by which it is carried out.
(265) This is known as the “mule,” and owing to the practical automaticity of its mechanism, as the “self-acting” mule or “self actor.” 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. In order to understand the description which follows, it will be advisable to define the stages or periods which succeed each other and form the entire process.
(266) In order to facilitate the grasp of the subject by the reader, it will be better to describe first and briefly the essential or primary parts of the machine. These are shown in Fig. [148], which is a purely diagrammatic representation. The roving bobbins A are fitted on a skewer and placed in the frame or creel arranged at the back of the machine, being held in an almost vertical position. The roving R is guided as shown to the nip of triple lines of drawing rollers B B B. From the rollers the roving passes to the tip or point of a steel spindle H, sustained by an upper bearing or bolster O, and a footstep N. These are fixed in wooden rails which form part of a box or frame I, known as the “carriage.” The carriage is fitted at convenient distances along its length, with cross brackets, in each end of which bearings are formed for the axes of the pulleys or runners P. These rest upon the edges of oblong iron bars or “slips” Q, which are securely fastened to the floor of the room. The spindle receives a rapid rotary motion, being driven by a band M, carried tightly round a small V grooved pulley or “warve” fixed on the spindle, and a light roller K extending longitudinally of the carriage, and fastened on a shaft T. The roller—or more correctly the “tin roller”—K is suitably driven, and, it will be easily understood that the direction and velocity of H will depend upon those of K. In its passage to the spindle the roving is taken under a small guide wire D—known as the “faller wire” or shortly the winding “faller”—fastened on the outer end of a curved arm or “sickle” secured on the shaft F—known as the “faller shaft.” The roving also passes over a second wire C—called the “counter faller”—which is fixed in a similarly shaped arm fastened on the “counter faller shaft” E. By the oscillation of the shafts E F, the winding faller and counter faller are elevated or depressed, thus enabling the finished yarn to be wound into the spool or “cop” G, which is made of the shape shown. The above form the essential portions of a mule and their respective functions can now be explained.
(267) The rollers B perform the same office as those used in the drawing and roving machines, namely, the attenuation and delivery of the roving. Each of the three lines revolve at different velocities, that of the front line being the superior one, with the result that roving which, as was shown, has been already considerably reduced in diameter is still further attenuated prior to being twisted.
(268) The roving is wrapped round the spindle two or three times in commencing operations, being sometimes rendered adhesive by paste, and sometimes wrapped on a paper tube placed on the spindle. Being thus held at one end by the spindle, and at the other by the nip of the front rollers, the rotation of the former will necessarily further twist the partially twisted roving. On the degree of twist—that is the number of turns per inch—depends the amount of roving delivered by the rollers in a given time, as explained in paragraph 234.