coupling members 31 and 30 has a respective central axis a and b which extends parallel to the edges where the web of the u joins the legs thereof the central axes a b of the slots 40 of the respective socket 42 of the female coupling members 31 and 30 are arranged at an angle of 80 u00b0 100 u00b0 with respect to one another this arrangement means that for the coupling and releasing of two magazines two motions have to take place the motions of the two magazines 10 and 10 39 are shown in fig3 with arrows 1 2 for performing the coupling operation and with arrows i and ii for performing the disconnection release thereof thus for performing the coupling operation first the two upper coupling parts 31 33 39 of the respective magazines 10 and 10 39 are to be joined to one another by means of a longitudinal displacement of the magazines with respect to one another and thereafter the two lower coupling parts 30 and 32 39 are joined together by means of a relative rotary motion of the magazines 10 10 39 about the upper coupling parts 31 and 33 39 for separating releasing the two magazines from one another the magazine 10 39 which is closer to the viewer in fig3 is first rotated with respect to the magazine 10 in the direction of the arrow ii and then shifted parallel to the arrow i relative to the magazine 10 reverting once again to fig1 and 2 and also referring to fig4 each magazine is provided with ribs 34 35 36 and 37 which.