Joining cart and spinning machines

The present invention provides a direction between the plurality of spinning units (2) on the rail (41a) and a lower rail (41b) moves the yarn splicing cart (3), comprising: abutting the upper rail and the upper guide (41a) roller pair (350), the upper guide roller pair (350) a handover bracket and the upper rail (41a) comes into an abutting position and away from the upper rail (41a) away from the position (360), mounting the switching bracket ( 360), moving along the track (41a, 41b) the housing (300). The guide roller pair (350) by switching the position of the switching bracket (360) on the side, so that splicing cart (3) with respect to the detachable rail (41a, 41b) becomes easy. Capable of splicing cart (3) in any position of loading and unloading, the end portion does not need the like on a rail (41a) is provided splicing cart (3) with detachable space.