Control of Yarn
Up to this point the yarn guides and carriers have been mentioned only incidentally so we will now take them up in more detail. Where there is only one thread and guide on a machine it is a very simple matter to control it but in the modern full automatic machines, where there are several threads and guides, and they must be arranged so that any one on a single lock machine, or any two on a double lock, may be selected at will, it becomes more of a problem. There is another point that must be taken into consideration in connection with this. That is, in the automatic machines the carriage must travel the full length of the machine but much of the fabric made on these machines does not take the whole width. Therefore if the yarn carrier was carried the full length with the locks there would be at the end of each course a considerable length of yarn, reaching from the edge of the fabric to the yarn carrier, which it would be very difficult, if not impossible, to draw back through the yarn guide. There must be no slack yarn between the edge of the fabric and the yarn guide when starting to knit across on a course.
To obviate these difficulties the yarn carriers are attached to blocks which in turn are mounted on ways or bars which reach the full length of the machine and may be seen in Fig. 46, and are indicated by the figures 1, 2, 3 and 4 in white. This has been explained in part before, together with the manner of operating the carriers with plungers, but I wish to call the reader’s attention to it again as it has a direct connection with what follows.
To prevent the yarn carrier from following the locks to the end of their travel, and thereby accumulating yarn between the guide and the edge of the fabric, there is a stop placed at each end of the fabric to stop the carrier at the proper point. One of these stops may be seen in Fig. 49, at Q. This may be placed in any desired spot and is held in place by a pin which engages in one of the holes in the way or bar, which holes may be plainly seen.
This stop consists of a base or block which slides on to the way on the dovetail principle. On the top edge of this base there is a thin strip about 4 inches long by about one-half inch wide, which is beveled down from the top to the bottom edge on both ends. When the carriage with the yarn carrier approaches this stop the carrier comes just under this top strip and the point of the strip comes just under the end of the plunger X, Fig. 48, also Fig. 52, which as explained before moves the yarn carrier. As the carriage moves farther along, the plunger slides up the incline or bevel of the strip and is raised out of engagement with the shoulder on the yarn carrier block, and the carrier stops while the carriage completes the length of its travel.
Upon the return of the carriage the plunger will slide over the strip on the stop, drop into the opening of the yarn carrier block, and engage the opposite shoulder and take the yarn carrier back with it on the return course, where it will be released on the other side in the same manner as just explained.