Patent GB-637899-A (GB)
Title: Improvements in automatic looms for weaving
IPC: D03D45/20
Filed: 1948-02-27
Abstract: 637,899. Automatic cop changing in looms. SHIMWELL, D. W. Feb. 27, 1948, No. 6028. [Classes 142 (i), 142 (ii) and 142 (iii)] In the mechanism described in Specification 632,245 (in which the shuttle crosses the loom empty after the remnant of a cop has been extracted from it), the hook which extracts the cop remnant pulls a cable n, Fig. 1, attached to a striker c pivoted on the weft fork hammer b<SP>2</SP>; on the forward stroke of the hammer, the striker pushes a link e to raise a dog o into the path of a striker p on the slay, causing insertion of a fresh cop into the shuttle at the next beat-up. As the hammer reaches its fully forward position, a stop r encounters the breast beam h, thereby depressing the striker c, which snaps out of the forked end of the link e, whereupon the link is lifted above the level of the striker by a spring f. Fig. 6 shows mechanism for delaying the insertion of a fresh cop until the shuttle has crossed the loom empty six times (for instance, when weaving a six-leaf twill). In this case, the link e is carried by a lever 28, mounted loosely on a shaft 30, and the connection k (Fig. 1) to the dog o is taken from a lever 41 (Fig. 6) mounted loosely on the shaft 30 side by side with the lever 28. On the first forward stroke of the weft hammer after the cable n has raised the striker c, the striker engages the link e, thereby pushing the lever 28 forward, whereupon a catch 36 (pivoted to the lever) drops in front of a fixed platform 37 to prevent the lever from moving back again. An arm 40, pivoted to the lever 41 and previously supported by the catch 36, can then fall until a catch 42 carried by it rests on top of a block 37a; on the second forward strike of the weft hammer, a pin 44 on the hammer encounters a shoulder 46 on the arm 40 and pushes it forward so that the catch 42 drops into a notch 43. When the weft fork hammer moves backwards, the arm 40 can then drop still further, so that on the third forward movement of the hammer the pin 44 meets the end 40a of the arm 40, pushing it so far forward that the lever 41 raises the dog o as in Fig. 1. This mechanism can be adapted for plain weaving by coupling the levers 28, 41 together so that the lever 41 is operated on the first forward stroke of the weft fork hammer. For weaving a four-leaf twill, in which case the shuttle makes four traverses empty, similar mechanism is used, but the arm 40 has no shoulder 46 or catch 42, and its end 40a is engaged by the pin 44 on the second forward stroke of the weft fork hammer. Take-up motion. While the shuttle is crossing the loom empty, the take-up is interrupted by a connection (from the scissors shown in the prior Specification) which lifts the holding pawl from the ratchet wheel on the take-up roller; the pawl is then held out of action by a catch, which is released by a connection from the cop inserter when this operates. Weft fork motion. Stoppage of the loom by the weft fork while the shuttle is crossing the loom empty is impossible on the first forward stroke of the weft hammer, since a shoulder b<SP>2</SP> provided for operating the weft fork, is integral with the striker c and is therefore below the lever of the weft fork tail when the striker c is raised. In the mechanism shown in Fig. 6, operation of the weft fork after the shoulder b<SP>2</SP> has returned to its normal position is prevented by. an arm 47 attached to the lever 28 which, due to the forward movement of the lever, holds the tail of the weft form above the shoulder b<SP>2</SP>.