the hubs 30 are so mounted about the opening 26 that its teeth 34 extend into the opening 26 for driving engagement with the tape drive spindle as clearly shown in fig3 to fix the clamp 10 in position on the tape cassette 20 shown in fig4 the clamp 10 is pushed into position over the chamfered edge 22 39 with the clip 16 bent inwards as shown in chain dotted lines in fig2 to enable the projection 18 to move over the inner wall of the opening 26 and the inner edge of the hub 30 the projections 18 then snap into position against the chamfered edge 24 39 of housing member 24 it will be understood that to hold the clips in position the ends of the projections 18 must be spaced a distance w 1 when the clips are entirely unstressed which is larger than the diameter d 1 of opening 26 and that the axial dimension of the tongues 16 is the same as the distance between the opposite surfaces of the cassette housing 20 so that the tipped ends of the projections 18 engage the chamfered edge 24 39 with the clamp being held in position unstressed the opposite sides of the tongues 16 at a point intermediate the member 12 and.