Abstract: An arrangement for forming sheds in a weaving machine having a plurality of operatively mounted heald shafts forming a heald shaft system. A drive shaft is rotatably mounted in the weaving machine and a plurality of eccentrics are non-rotatably mounted on the drive shaft one behind the other. A bearing is mounted on each eccentric; a rim member is mounted on each bearing and a sleeve is mounted on the rim member. One tie rod is pivotally connected to the rim member and another tie rod is threadably connected to the sleeve. The tie rods are connected via suitable linkages to the heald shaft. When the drive shaft rotates the heald shaft is reciprocated by the action of the eccentrics on the bearing and rim member.