During weaving, a shed or opening is formed between the top and bottom warp yarns as they cross and recross through a center axis. The top and bottom yarns or "warps" are supported by harness members which control their action and the harness members are suitably connected to treadle levers which are raised and lowered in accordance with the motion of harness cams which the treadle levers or treadles are in contact with.
As the top and bottom warp yarns open to form the shed, inserted therebetween is a weft or filling yarn or "pick" sometimes referred to as the "pick of filling". This pick is urged tightly into the fell of the fabric (where the top and bottom warps meet) by the action of a loom reed. As the reed begins urging the pick into the fell the warps of yarn begin crossing and contacts the pick prior to its reaching the fell and final beat-up or compactment by the reed. Consequently, the scissoring or "squeezing" action which is applied by the crossing warps to the pick sometimes prevents the pick from being compacted or completely nudged into the fell. This incomplete beat-up of the pick can oftentimes result in a fabric having a shaded appearance due to the pick of filling, which is often lighter yarn than the warp yarns, showing through, or blossoming to the surface of the fabric, because the crossing warps which pinch or squeeze the pick of filling yarn prior to beat-up tend to pull the pick up and down between the warp yarns and it rises to the surface of the fabric. The shading effect is generally more noticeable on one side of the fabric due to the pick being released on one side prior to the release by the pick insertion mechanism on the opposite side.
In addition to shading problems, conventional harness control assemblies contribute to other problems during the weaving process such as pick insertion tape breakage, wear of various harness parts, low loom weaving efficiency and poor quality of fabrics woven, and the fabrics thus produced often have to be disposed of as "seconds".
With this background in mind, the present invention was conceived and one of its objectives is to provide a loom mechanism which delays the harness crossing approximately 40.degree. during the weaving cycle beyond the timing normally found in a 360.degree. weaving cycle.
It is another objective of the present invention to provide a loom mechanism which will allow the harness to cross at approximately 320.degree. of the weaving cycle.
It is another objective of the present invention to provide a loom mechanism which will reduce the pick insertion tape breakage.
It is yet another objective of the present invention to provide a loom mechanism which will reduce the wear and breakage of the various harness parts and will provide longer usage life.
It is still another objective of the present invention to provide a loom mechanism which will improve the efficiency of the loom and reduce the yardage of "seconds".