Abstract: A rigid caltrop structure is formed of two metallic members abutting each other and welded together, each of the members including all of a single triangular planar portion and parts of two other adjoining triangular planar portions, the pairs of adjacent corners of sides of the triangular portions forming penetration points so that when three of the penetration points rest on a horizontal surface and the fourth penetration point projects upward, a force applied to that fourth penetration point will not directly tend to shear the weld.

Abstract: A towel clip holds a towel in place on a chair back of an outdoor chair such as a beach chair or lounge chair. The clip includes a generally C-shaped semirigid clip member, a pair of side-by-side first clamping members of generally spherical shape on one end of the C, and a second pair of generally spherically shaped clamping members on the other end of the C. The first pair of the clamping members are arranged side by side and the second pair of clamping members are arranged front to rear so that the respective pair of clamping members extend along mutually orthogonal axes. The C-shaped clip is made from a plastic material having a recovery force that holds the spherically-shaped clamping members under slight tension normally so that one pair of clamping members interlocks within a narrow space between the other pair of clamping members and vice versa.