(375) The ring, the use of which gives its name to the system, is made of the form shown in the drawings, and varies in diameter from 1 inch to 5 or 6 inches, as required, 2 inches being a very common size. The diameter is, of course, determined by the counts being spun, the cop or spool produced being larger in proportion to the coarseness of the counts. A table of the ordinary sizes employed will be found at the end of this chapter. The important points in a ring are its perfect circularity, smoothness of surface, and hardness, three features which tax the energies of manufacturers to obtain at the prices paid for these articles, Formerly rings were produced out of iron of good quality, which was formed into a hoop and perfectly welded, but latterly steel has come largely into use, and it is the practice to obtain the blank without a joint. The rings are in some cases milled, and in others turned and bored to the required section, and are subsequently case-hardened. A large percentage of the soft rings fail in the case-hardening, and the production of a perfect article is only possible with a proportion of the blanks dealt with. In the great majority of cases the ring is made single—that is, with one bead only (Fig. 195)—but Messrs. Thomas Coulthard and Co., of Preston, produce a double ring, shown in Fig. 196, which can be reversed when needed. This firm provide a special holder for their ring, which is fitted on to the rail, and is also formed with a vertical arm or projection which knocks the fly off the traveller as the latter revolves. The fly is—as explained—the collection of loose fibres which are thrown off from the surface of the yarn in its passage to the spindle, and which if left adhering to the ring or traveller increases the drag and causes breakage. It may be repeated here that cleanliness is a most important feature, and requires constant attainment if spinning is to be conducted successfully. A special lubricant is provided for the ring and traveller, ordinary oils being useless.
(376) The travellers are, as previously mentioned, made of a =C= shape, but this is not invariable, and are of various weights to suit varying circumstances. There are two standards of weight used in manufacturing travellers in this country, one known as the Scotch and the other as the United States. The Scotch standard probably derived its name from the fact that it was originally, and still is, manufactured in Paisley, by Messrs. Eadie Brothers. The difference between the two lies in the size of the bow for fine numbers from 1/0 to 3/0—used in spinning 28’s counts yarn and finer. The smaller bow is used in the Scotch standard, and it enables a thicker steel to be used, giving greater strength to the traveller and preventing it being pulled off the ring so easily. Thus, in spinning 32’s, a number 2/0 to 3/0 Scotch standard can be used, whereas the number in United States standard would be 3/0 to 4/0. For fine yarns a light traveller is necessary, while for coarse counts or strong doubled yarn a proportionately heavier one is used. A good deal depends, however, on the quality of cotton used, good Sea Island, for instance, enabling yarn to be spun with a traveller three or four sizes heavier than that permissible with inferior cotton. The diameter of the ring used, the number of twists per inch, and the speed of the spindles are among the things which influence the choice of the traveller used. It may be said that, although definite rules are made as to the weight of traveller used for certain counts under fixed conditions, a careful overlooker can make a vast difference in the production by selecting the exact size of traveller best adapted to particular yarns.