Abstract: Apparatus for holding and supporting a string of connected drill pipe sections which are suspended in a bore hole and for assisting in separating one drill pipe section from the string when the string is being disassembled.

Abstract: A modular structural system utilizes a limited inventory of framework elements which in combination with a limited number of interstitial exterior and interior panels can be utilized to erect a variety of integral structures in which the framework elements bear substantially all loads. The same framework elements can be combined to form planar trusses and spans, domical space enclosing structures with integral foundations, and complex multi-level high rise structures. Polyhedral frameworks are assembled into arrays of interlinked triangulated segments for optimum stability.

Abstract: A kite having a prism-shaped three dimensional frame, spanned by aerodynamic surfaces on its two downward disposed faces. The top or upward disposed face is spanned by a novel aerodynamic surface called an air dam which operates to stabilize the flight of the kite while greatly increasing the lift. A tail consisting of struts spanned by an aerodynamic surface is also provided. The frame is built from a number of identical struts and identical connectors. Each aerodynamic surface consists of two unitary congruent sheets positioned facewise against each other and joined together along their edges. The struts are inserted between the sheets along the edges where the sheets are joined together. This simple basic structure facilitates assembly and reduces cost while providing a high strength-to-weight ratio and stable flying qualities. Combination kites may be assembled by joining several basic kites in various ways.

Abstract: A tetrahedral kite having a sail formed by a pair of sheets of rhombus shape that lie facewise against one another and are joined together along their edges. The middle of the rhombus-shaped sail is folded about an edge of the tetrahedral kite frame so that the sail portions one either side of the middle line cover one surface of the tetrahedron, the edges of the sail being held by struts of the kite frame that lie sandwiched between the two sheets of the sail along the edges thereof.

Abstract: A plurality of mathematically interrelated modular structures are disclosed which are based on a series of minimal surfaces bounded by skewed polygons. Some six basic modules are described which are capable of being interconnected in various combinations to form finite volume enclosing structures. Appropriately scaled, the modules could be used as structure toys, to create playground equipment or, for the construction of habitible structures. Utilizing these structural modules, it is possible to construct large assemblies having parallel planar structures within the enclosed space which could be considered floors and ceilings of multilevel structures.