support a drive shaft and pivot pins on which oscillating members are moveably pivoted by a drawing system to the heddle frames of the weaving machine application_number US 64164896 A description referring now to the drawings and firstly to fig1 and 2 reference 1 designates the beam or housing which constitutes simultaneously the support frame and the casing of the weaving system this beam 1 presents an upwardly open u section which is defined by a flat bottom 2 two longitudinal side walls 3 and two transverse end partitions or walls 4 the end walls ensure a perfectly tight closure so that the beam 1 can contain a quantity of oil referenced 5 in fig2 without leakage at one of the ends of beam 1 the two side walls 3 include two upstanding lateral cheeks 6 although in the embodiment illustrated the cheeks 6 are directly secured to the side walls 3 they may equally well be constituted by two plates added by welding or bolting on the side walls in wall 3 and in cheeks 6 are made four pairs of openings referenced 7 8 9 and 10 respectively it being observed that the two openings of each pair are aligned transversely on one and the other wall or cheek the pair of openings 7 receive roller bearings not shown which support the drive shaft 11 for driving the rods 12 actuating a rotary dobby the pair of openings 8 receive the ends of a fixed pin 13 on which all the oscillating members 14 pivot in each of the pairs of openings 9 and 10 are retained the ends of fixed pins 15 which form common pivots for assemblies of return.