Patent GB-190226322-A (GB)
Title: New or Improved Cross Weave Mechanism for Power Looms for Weaving
Inventor: HOLLINGWORTH EDWARD
Filed: 1902-11-29
Granted: 1903-11-05
Abstract: 26,322. Hollingworth, E., [Hutchings, G. F., and Ryon, E. H.]. Nov. 29. Loom shedding-motions; dobbies; warp tension, regulating; shuttle-races.-Relates to cross-weave mechanism. When the shed is being formed, groups of warp threads are engaged by forked needles 21, Fig. 4, extending downwards in front of the reed, and carried over adjacent groups of threads and then downwards to form the bottom of the shed, while the remaining threads are raised to form the upper part thereof. The needles are carried by a vertically and longitudinally moving bar 20 mounted on the lay and operated, as the lay moves forwards and backwards, by a plain guide 48, Figs. 4 and 6, and a cam-surface 56, both of which are automatically adjusted according to the pattern by means of the levers shown and cams 41, 42, the axle of which is rotated intermittently from a suitable jack lever through ratchet gearing. The needle-bar is normally held in its raised position by a system of levers and a spring, and, when it is required to be lowered, the action of the spring levers is overcome by the jack lever of the pattern mechanism, the extent of the downward movement being limited by a cam secured to the frame. In the shedding operation, those threads which, are to be engaged by the needles and ultimately form the bottom of the shed, must first be raised and crossed over in the manner desired, before the threads which are to form the top of the shed are raised. A given heald may, therefore, be sometimes required to be raised at an earlier and sometimes at a later period in the formation of the shed, and for this purpose an additional knife-bar and set of hooked levers is attached to the dobby, and the heald has two independent sets of connections by which it may be raised. The additional knife-bar, however, is caused to reciprocate at twice the rate of the ordinary ones, so that, when the heald is raised by its means, the lift does not commence till a later period, but takes place quicker than in the former case. Fig. 13 represents a suitable form of dobby. The ordinary knife-bars 90, 91 work in connection with the hooks 95, which are supported by the forked ends of weighted levers 204 operated by the pattern chain. The auxiliary knife-bar 93 engages with the notched ends of levers 212, which slide on the upper hooks 95 and are pivoted to levers 211. which are connected by looped rods 216 to the heald and to the jack lever 218, the arrangement being such that the jack lever may be moved in the ordinary way to raise the heald without operating the lever 211, and the lever 211 may also be moved to raise the heald without operating the jack lever 218. The pattern chain may support the levers 204 at three different levels. When the lever 204 is in its lowest position, the hooks 95 are out of range of the knife-bars 90, 91, and the lever 212 only is operated by the knife-bar 93 ; in the intermediate position, both the knife hooks and the levers 212 are out of range of their respective knife-bars, while, when the lever 204 is in its highest position, the hooks 95 are engaged by their knife-bars while the lever 212 is free. Fig. 11 shows the mechanism for easing the tension on the yarn during the crossing-over operation. The threads are passed over a roller 135 on the end of a lever 134, 124, which is normally held in a position to apply tension to the yarn by reason of the engagement of the lower hooked end 125' of a spring-catch lever 125 with a bracket 117 on the frame. When the threads are being crossed, the catch lever 125 is disengaged by a connection 127 with a jack lever of the dobby, and the tension on the yarn is released, the upper hooked end 125<11> of the lever 125 being engaged by the vertically-reciprocating plate 118', which, on its downward movement, serves to set the parts in their original position. In a modification, two needle-bars are provided, which can be raised and lowered simultaneously ; or one can be held in the raised position while the other only is lowered into the shed. The needleholders are adjustable on the bars, and those on one of the bars may be slotted so as to act as guides for the other bar. A series of pins extend vertically through the lay, and are automatically raised at every pick to serve as a guide for the flying shuttle and as a protection to the forked needles.