Transverse air-jets for high speed shedding in looms

With the demand for even higher speed weaving of narrow fabrics, one limitation has been found in the shedding mechanisms, which divide the threads to allow the weft to pass across. They also limit the facility with which pattern can be, introduced into the woven fabric. Because of the inertia of these mechanisms which are usually of the cam and follower type, to make them move faster, larger and larger forces are required. This gives rise to difficulties in constructing them and in driving them. Major increases in speed seem now to be unlikely. In July 1972, one of the leading British manufacturers of high speed narrow fabric looms asked the Engineering Design Centre at Loughborough University of Technology for a new higher speed shedding mechanism hopefully capable of 5000 pick per minute (nearly twice the existing speed). This thesis describes the devising of a shedding device patented in April 1974, based on a new idea entirely different from mechanisms used so far. The analysis and results of two sets of static and dynamic tests followed by recommendations for further improvements is included.