Fig. 13.J.N.
(49) However the cylinder is constructed it is sustained by bearings secured to the framing of the machine. Beneath it a grating or grid is fixed, similar in construction to those previously described. The bars are in all cases shaped so as to present a sharp angle to the cotton as it is thrown forward by the cylinder. A dirt chamber is, as usual, formed below the grid. The cotton is fed by a lattice and feed rollers. The latter are formed in the ordinary way, with a number of circumferential V grooves, crossed by a series of similar longitudinal grooves, so as to form a large number of teeth, which securely hold the material as it is fed. As the cylinder revolves 1,000 times per minute, the teeth strike the cotton and disentangle the fibres, throwing them with considerable force against the grid.
(50) Although the Porcupine opener can be used separately and the cotton discharged into the room, it is more usually employed in connection with some other type of opener, or with a scutching machine. Formerly it was a common practice to use this machine separately, in which case it was fitted with two cylinders one behind the other. Now it is mostly employed as a feeder to another machine, and the combination gives very effective cleaning.
(51) Such an arrangement is shown in Fig. [13], which is a special one of Messrs. Platt Bros. and Co. The lattice feed F is placed alongside the mixing bins, and is provided with a large collecting roller, behind which are a series of pedals, described in the next chapter, and two pairs of breaker cylinders. By these the cotton is fed regularly and broken up into small pieces, or partially opened before being passed forward to the opener cylinder. The Porcupine feed rollers G deliver the cotton, in the case illustrated, into the air tubes D, and thence over a patent dust trunk K, where much of the dirt is deposited, and which is afterwards described.
Fig. 14.
(52) The opener, as made by Messrs. Platt Brothers and Co., Limited, is shown in perspective in Fig. [14]. The cotton enters the opener chamber by the tube, as described, and is at once acted on by the cylinder, which revolves horizontally. The cylinder is surrounded by grids, against which the cotton is thrown, and through which the dirt is ejected. The forward movement of the cotton is induced by the exhaustion of the air, produced by means of a pair of fans, placed one at each side of the machine and adjoining the exit orifice from the cylinder chamber. Power of lateral adjustment is given to these fans, so that they may be set in towards the centre of the machine to a greater or less extent. In this way the stream of cotton, as it issues from the cylinder, is directed on to the cages as required, and a very even lap or sheet is thus obtained. It is obvious that the guiding power of the air current is the right thing to rely upon, and, by the arrangement described, ample regulation of it is obtained. A lap which is even in thickness is absolutely essential to good work, and the arrangement of fans in the way described ensures this being obtained. The author recently saw the first lap made on a machine of this type in a large Oldham spinning mill, and the regularity of the thickness and evenness of the selvedge was very noticeable. The machine as shown in Fig. [14] is a combined one.
(53) The Crighton Opener is a machine the distinctive feature of which is the employment of a vertical conical beater. A sectional elevation of the machine as made by Messrs. Crighton and Sons is shown in Fig. [15]. The beater consists of a number of cast-iron discs D securely keyed upon a vertical shaft, which is sustained at its lower end by a bearing E in the frame F, and at its upper end by the bearing A. On the discs are fastened steel blades, and it will be noticed that their diameter increases from 18in. to 33in. Surrounding the beater is a casing B, in which are a number of longitudinal slots, the inner surface of the grids being in most cases made of the shape shown in section in Fig. [16]. A recent improvement by Messrs. Crighton and Sons is shown in Figs. [17], [18], and [19].
