| 摘要 |
A reciprocating double lift dobby operating an open shed has a pair of drive members 1, 2 which reciprocate at half the loom frequency and 180 degrees out of phase, one above and the other below a series of shafts 3 which are connected one to each of the loom harnesses and each of which is movable by either drive member between a pair of stationary positions, corresponding to the base positions of the open shed, when required to do so by the weave pattern. One of the stationary positions is defined by a fixed member 5 engaging a stop 15 on the shaft 3, and the other is defined by a catch 8 which engages a lug 18 on the shaft. In each loom cycle, each shaft 3 will either remain in one or other of the stationary positions or will be moved from one to the other depending on the positions adopted by linked selection levers 9, 10, 20 which are controlled by the weave pattern. If a shaft 3 is required to move, the levers 9, 10 will cause a catch 6, 7 on the first of the two drive members 1, 2 which arrives at the current stationary position of the shaft to engage a lug 16, 17 on the shaft and move the shaft to the other stationary position on the next stroke of the drive member, the lever 20 engaging or releasing the catch 8 as necessary. If a shaft 3 is not required to move, the levers 9, 10 do not act on the catches 6, 7 and the drive members 1,2 do not disturb the shaft from its stationary position.
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