Fig. 223.J.N.
(414) An important improvement in ring bobbins has been recently adopted by Messrs. Wilson Brothers, Limited. This is a mode of enamelling or coating them with a composition which is entirely impervious to damp. The plan is an American one, but a series of tests made by the author show that bobbins treated in this way can be subjected to the action of hot or cold water or oil without being in the least affected. It is a very usual practice in preparing yarns for weaving purposes to “condition” them—that is, to allow them to absorb a certain amount of moisture. This is often done while they are wound on the spool or bobbin, and the result is that the latter speedily lose their form and become out of balance. By coating them as described this evil is avoided, and yarn can be conditioned with impunity while on the bobbins.
(415) In order to ascertain the counts of yarn, a machine known as a “wrap reel” is employed. This consists of a small fly or swift similar in form to the swift employed in the reels described in the last chapter, but smaller. This is revolved by a sun and planet arrangement of wheels which is, in principle, like the differential motion described in Chapter [X]. A short hank of yarn—one lea or 120 yards—is wound on the wrap reel, the time when the exact length is wound being denoted by the sounding of a bell, when, as the winding is a manual operation, the machine can be stopped. The hank so formed is taken off the reel and weighed, and the weight of a full hank can thus be easily ascertained. By the aid of a table the counts of any of the short hanks wrapped can be easily ascertained. By means of a small machine, the strength of the yarn can be tested, the pull upon it being obtained by a weighted arm. An indicating apparatus is provided, by which the weight of the pull is registered.
(416) During the past few years one or two simple graduated indicators or scales have been introduced, by which the weight of a piece of cloth can be readily obtained. One of these, “Staub’s,” has been introduced into this country by Messrs. George Thomas and Co., and by its aid the counts of either the warp or weft in a piece of cloth can be readily ascertained. It differs in form from the scale shown in Fig. [224], but is based upon the same principles. In the form shown in Fig. [224]—which is Niess’ scale, and is controlled in England by Mr. Charles Lancaster—a light hinged arm is formed at one end with a hook, on which a length of 40 yards of yarn can be hung. This causes the arm to be depressed, and a pointer finger traverses the face of a graduated quadrant, a glance at which is sufficient to show the counts of yarn. These yarn balances are simple and reliable, and are being used in increasing numbers.
Fig. 224.
Fig. 225.
