Abstract: 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.