Abstract: A snap fastener stud (S) for accommodating receivers (R) of varying thickness has a generally pear-shaped head with latching and retaining seats (38 and 40) therebeneath on opposite sides of the stud with the retaining seat having a radius of curvature (t) substantially greater than the radius of curvature (r) of the confronting surface of the receiver (R). In a modification the stud is capable of receiving a plurality of receivers (R.sub.1 and R.sub.3). The receivers may be formed with an annulus (72) which is separate from the portions (86 and 88) which are crimped to the fabric (F). The stud (S) has ribs (116) for preventing rotation on a surface on which the stud is mounted and a saddle shaped adapter (110) enables mounting of the stud on a cylindrical support (TF).

Abstract: A multi-ratio drive utilizing a chain link or a belt segment specifically designed to engage a sprocket having a plurality of cylindrical pins radially spaced from one another in a circular array. The chain links or belt segments are connected to one another to form a flexible tensile member. The chain embodiment is formed of a plurality of link plates each having a first and second end pivotably attached to one another and extending along a chain axis. Each link is provided with two teeth projecting transversally from the chain axis and each having a concave drive face having a radii substantially equal to that of the sprocket pins to be engaged thereby.