This process of changing from the single to the double shed is accomplished by the use of a specially designed cam jack made in two sections, to which are attached two harness frames, in each of which one side of the strap is drawn. While weaving the plain part of the strap both sections of the cam jack operate in unison, running side by side from the same cam, but when the buttonhole is “called on” a device for spreading apart each pair of cam jacks is operated, and the two sheds are then formed. At the same time a lever movement changes the position of the lay, so that the two banks of shuttles take new positions and properly engage the two sheds.
Facilities are provided for governing the length of the straps and the position and length of the buttonholes. When the lower shuttle is not engaged in the buttonhole shed, the filling may run loosely beneath the goods, and require trimming off between the buttonholes. This trimming may be avoided by operating the center binder thread, putting the same in a skeleton harness and giving it an extended shedding so that this particular thread may be dropped below the main shed and allow the lower shuttle to engage it. By this process the thread is bound in the goods at every pick of the loom and does not need trimming.
The elastic back end, having a buttonhole in it, is also made on a special loom, which has a “rise and fall” movement of the lay. It has a chain fancy head with what is known as a Gem multiplier on it for regulating the length of the plain part, so that one repeat of the plain weave can be multiplied indefinitely and the buttonhole chain called on as desired.
In making up sections of elastic webs for various purposes, particularly when required to be attached to garments, it is often found that the joinings are bulky and unsightly on account of their thickness. A web is made on the special loom just described of such character that it does away with this objection. A section of plain web may be woven of any desired length, and then another section made in which the upper and lower cloth are woven separately for a given distance. After being taken from the loom this double section is cut in the middle, so that the non-elastic part may be used for attaching to the garment. When thus made the rubber and binder lie “dead” between the two cloths, and are trimmed off after the non-elastic part is cut in two.
Making Abdominal Belts
There is a growing demand for webs of various characters for surgical and orthopedic purposes. One of these which calls for special attention is a web used in the manufacture of abdominal belts. The width varies from about four inches, where it is used to support the back, to about six inches at the part which is used for the support of the abdomen.
Such a web is constructed in the regular manner employed on plain webs, except that it is woven in a deep front reed made to taper from top to bottom, from fine to coarse. This reed is arranged in a reed pocket attached to the lay bed, and is designed to slide up and down behind it. Underneath the lay is an adjustable screw mechanism, which is so operated that it can be made to remain stationary for a given length of time, and then gradually work up and down in a given period. This allows a web to be produced with a formation similar to that shown at Fig. 6.
The rubber cords lie close together while weaving the first narrow part, and gradually spread while operating at the wide part, returning to their original position for the other narrow end. If properly constructed the goods will lie perfectly flat at the narrow ends, and the opening up of the cords by the spreading of the reed dents at the wide center will give more freedom to the individual strands of rubber in this section, which will cause the goods to “belly” at this point. This rounding formation especially adapts them for the purposes for which they are intended. Various modifications of the taper web may be made in this manner, but the same general plan is applicable to all.