Abstract: A novel structural member, such as a tennis racket frame, having an unusually high strength to weight ratio is provided comprising an expanded foamed plastic core integrally bonded to a shell comprising at least one layer of resin-coated unidirectionally oriented graphite fibers, the shell completely encasing the core at any transverse cross section of the structural member, said core comprising from about 25 to about 75 volume percent of a low density cellular filler material, such as chopped cork, and from zero to about 60 weight percent of a high density weight control material, such as barium sulfate.

Abstract: A novel structural member, such as a golf club shaft or other tapered tubular member, having an unusually high resistance to torsional deflection for given desired longitudinal deflections along with high strength and a center of gravity more favoring the tip-end is provided by a resin-bonded graphite fiber structure in which the fiber orientations in each layer of the multi-layer, composite structure are varied along the length of the shaft and in desired orientation relationships between layers to achieve the unique combination of properties.This structural member is prepared by helically placing fiber yarns such as graphite onto a resin-coated, tapered steel mandrel by winding a series of high modulus graphite yarns in series of layers and progressively varying the rotational speed of the rings carrying the spools of the graphite fiber yarns in each layer as the mandrel is fed at a constant speed.

Abstract: A novel structural member, such as a tennis racket frame, having an unusually high strength to weight ratio is provided comprising an expanded foamed plastic core integrally bonded to a shell comprising at least one layer of resin-coated unidirectionally oriented graphite fibers, the shell completely encasing the core at any transverse cross section of the structural member, with a seamless sleeve made of a thin, flexible cellulosic film between the core and the shell.The structural member is prepared by arranging within a mold cavity an outer shell comprising at least one sheet of resin-coated unidirectionally oriented graphite fibers and a core comprising a foamable resin composition while the core is maintained within a seamless sleeve made of a thin, flexible cellulosic film, sealing the mold cavity and activating the foamable resin composition to cause expansion and generate pressure within the mold cavity and thereby provide intimate bonding of the core to the shell.

Abstract: A novel structural member, such as a tennis racket frame, having an unusually high strength to weight ratio is provided comprising an expanded foamed plastic core integrally bonded to a shell comprising at least one layer of resin-coated unidirectionally oriented graphite fibers, the shell completely encasing the core at any transverse cross section of the structural member, said core comprising from about 25 to about 75 volume percent of a low density cellular filler material, such as chopped cork, and from zero to about 60 weight percent of a high density weight control material, such as barium sulfate.

Abstract: A tennis racket assembly comprising a long structural member, a short structural member and two yoke pieces at the junction of said members. The long member extends from the grip end of the handle, up one side the handle, around the major portion of the ellipsoid head and down the other side of the handle to the grip end. The short member extends across the throat of the racket and completes the ellipsoid shape of the head, joining the long member at two junctions.Each yoke piece has the external shape of the letter "Y" and has at least two branch portions and a trunk portion. The trunk portion of each yoke piece is wrapped around a portion of the long member between the junction and the head of the racket, one branch portion of each yoke piece overlies a surface at one end of the short member, and the other end of each yoke piece overlies an opposite surface at said end of said short member.

Abstract: A novel structural member, such as a tennis racket frame, having an unusually high strength to weight ratio is provided comprising an expanded foamed plastic core integrally bonded to a shell comprising at least one layer of resin coated unidirectionally oriented graphite fibers, the shell completely encasing the core at any transverse cross section of the structural member.The structural member is prepared by arranging within a mold cavity an outer shell comprising at least one sheet of resin coated unidirectionally oriented graphite fibers and a core comprising a foamable resin composition, sealing the mold cavity and activating the foamable resin composition to cause expansion and generate pressure within the mold cavity and thereby provide intimate bonding of the core to the shell.