of the central section of the machine referring now also to fig2 and 3 each spinning station 12 includes a spinning unit 16 a yarn delivery roll assembly 18 and a yarn take up assembly 20 during normal operation of a spinning station 12 sliver not shown conducted to its spinning unit 16 is spun into yarn 22 which passes first downwardly from unit 16 to delivery roll assembly 18 and then passes upwardly to take up assembly 20 where it is wound upon a rotating bobbin to form a yarn package as is well known to those skilled in the art spinning stations 12 must be serviced in various respects the rotor or spinning chamber component not shown of each spinning unit 16 must be periodically cleaned if the yarn 22 at a station 12 should break a so called 34 piecing 34 operation must be performed to restore the station to production additionally when the desired amount of yarn has been wound upon the bobbin at a station 12 an empty bobbin must be substituted for the full one it has heretofore been proposed to provide in association with open end spinning machines mobile servicing apparatuses that move about the machines to the various spinning stations thereof and that automatically perform all or desired ones of the aforesaid servicing functions such a mobile apparatus is designated in its entirety in fig1 3 of the drawings by the numeral 24 the servicing components of apparatus 24 are not shown in the drawings since they do not form part of the present invention and may be of any type suitable for the automatic.