Abstract: A hinge apparatus is disclosed, in which at least two flexible strips (1-3) are articulated, each via two articulation grooves (7, 8), to two parts (5, 6) that are movable relative to one another and are substantially cylindrical in embodiment, in such a manner that upon a relative movement of the two parts with respect to one another out of one stable position into the other stable position, the flexible strips are located in a substantially radial plane of the two parts (FIG. 3a).

Abstract: A resilient golf swing practice base having a preferred swing path; an upper surface with ribbing aligned parallel to the swing path to provide a visual guide for the path; a bottom surface with ribbing aligned transverse to the path to engage the ground and inhibit movement when the base is struck along the preferred path, the bottom and top ribbing together providing the resiliency, the bottom ribbing being of graduated height to produce a convex profile to the upper surface along the preferred path. The shoulders of an aperture positioned in the base at the maximum elevation in the convex profile support the golf ball.

Abstract: A snap-hinge in which two hinge members are hinged together about a first hinge line. A resilient connecting link is joined at one end integrally to one of the hinge members at a second hinge line and is hinged at the other end to the other hinge member at a third hinge line. The connecting link is capable either of compression or .[.of expansion.]. .Iadd.deformation .Iaddend.as between its two ends, and tends to maintain the hinge members in a given angular relationship, and to return the hinge members to that relationship if they depart from it.