threads are wound on the warp beam shaft 4 between the warp beam disks 5 the loom further contains a drive unit 6 for the warp beam 2 drive unit 6 in turn contains a drive motor 7 and a gear 9 affixed to the motor shaft 8 so as to rotate with the shaft the gear 9 meshes with a gear 10 that can be mounted on an attachment 11 of the warp beam shaft 4 in a manner discussed below and which can be affixed by a clamping element 12 gear 10 is held in place by a displacement mechanism 14 and can be moved in the direction of the axis 13 of the warp beam 2 onto the attachment 11 of the warp beam shaft 4 the displacement mechanism 14 includes a holder 15 affixed by screws to the gear 10 in a zone away from the gear 10 the holder 15 includes an undercut clearance 16 in which is mounted with comparatively large play a thickened head 17 of an actuator bar 18 the actuator bar 18 is fitted with a gear rack engaged by a gear 19 which can be rotated by a lever 20 or a crank in the situation shown in fig1 gear 10 is supported by gear 9 and further by means of the holder 15 by head 17 of the actuator bar 18 although those skilled in the art will appreciate that other or additional support means may be provided to support gear 10 in this situation gear.