A fastening device, comprising:
- a first fastening member having a plurality of teeth;
- a second fastening member having a plurality of sockets, each socket having a recess sized and shaped to receive and engage with one of the plurality of teeth;
- the plurality of teeth and sockets being sequentially engagable in tooth and socket pairs, in an engagement direction parallel to a first axis (X) which is orthogonal to second (Z) and third (Y) orthogonal axes;
- each tooth and socket pair being adapted for engagement by relative rotation of the associated tooth and socket;
- each tooth having a first surface and having a second surface spaced from the first surface in the engagement direction and fixed relative to the first surface;
- each recess being defined at least in part by a first wall of the socket and a second wall of the socket, the second wall of the socket being spaced from the first wall in the engagement direction and being fixed relative to the first wall;
- each tooth and socket pair having an engaged position wherein the associated tooth is received within the recess of the associated socket;
- in the engaged position the associated tooth and socket cooperating to prevent relative movement of the associated tooth and socket parallel to the first axis (X) and third axis (Y);
- upon engagement of a tooth and socket pair, the first and second surfaces of the associated tooth closely abut the respective first and second walls of the associated recess and prevent relative movement of the associated tooth and socket parallel to the first axis (X), and a portion of the first wall of the socket closely abutting the first surface of the associated tooth is disposed between the associated tooth and a portion of the first fastening member in a direction parallel to the third axis (Y) and prevents relative separation of the associated tooth and socket parallel to the third axis (Y);
- upon engagement of a first tooth and socket pair, relative movement of a tooth and socket of a second tooth and socket pair sequential to the first tooth and socket pair in the engagement direction being thereby substantially limited to relative rotational movement about a first pivot axis parallel to the second axis (Z), and the tooth and socket of the second tooth and socket pair being adapted for engagement by relative pivoting movement about the first pivot axis;
- upon subsequent engagement of the second tooth and socket pair, relative movement of a tooth and socket of a third tooth and socket pair sequential to the second tooth and socket pair in the engagement direction being thereby substantially limited to relative rotation about a second pivot axis parallel to the second axis (Z), and the tooth and socket of the third tooth and socket pair being adapted for engagement by relative pivoting movement about the second pivot axis, and subsequent engagement of the third tooth and socket pair being operable to substantially prevent relative rotation of the tooth and socket of the second tooth and socket pair about the first pivot axis;
- the first surface of each tooth has a profile as viewed parallel to the second axis (Z), and at least a portion of the profile of the first surface is concave and has a center of curvature on an associated tooth center of curvature;
- upon engagement of the first tooth and socket pair, the tooth center of curvature of the tooth of the second tooth and socket pair is substantially disposed on the first pivot axis;
- the first wall of the recess of each socket has a profile as viewed parallel to the second axis (Z), and at least a portion of the profile of the first wall is convex complementary to the first surface and has a center of curvature on a socket center of curvature;
- and
- in the engaged position of each tooth and socket pair, the tooth center of curvature of the associated tooth and the socket center of curvature of the associated socket are substantially located at the same point.