Position of Rolls
Fig. 4 will explain the position of the various rolls in relation to the breast beam. It will also show the peculiar formation of the shuttles used for this type of weaving, both pointing to one common center, made necessary by the character of the two sheds. The bow of the upper shuttle must be tipped downwards, and the lower bank must be tipped upwards, so as to reduce the friction of the shuttles all possible when they are passing through the sheds.
The round edge or covering for the outside rubber threads is drawn in the harness on the upper shed, and while being woven this cloth is pulled around the rubbers by the tension of the filling which is carried in the lower shuttle. This tension is greater than that carried in the upper shuttle, and so asserts itself by pulling the edge cloth around the outside rubber until it meets the back cloth weave. The upper and lower fillings are connected by what are known as tie threads. These threads are drawn in the harness at each side of the body warp, next to the edge, and are part of the binder warp. They are operated from the binder harness, but are only allowed to travel through the lower shed as far as the center of the web, instead of going all through both sheds, as do the balance of the binder warp. This movement is accomplished by the use of long looped harness eyes, which only carry these particular threads through the one shed.
Fig. 1.—Effective Combination of Weaves In a Fine Web
Figs. 2 and 3.—Sunken Effects
Fig. 1A.—Harness and Chain Draft for Fig. 1
Fig. 4.—Position of Rolls in Relation to Breast Beam for Cross Shot Weaving
The binder movement, extending through the two sheds, is formed by a longer sweep from extra throw cams, or by the use of extended cam jacks, or by a combination of both. The balance of these goods may be regulated both by the warp and the filling, and any tendency towards curling may be corrected by changing the weight of stock used on either.