Abstract: An improved racquet stringing machine having a new table featuring a built-in glide bar groove, an improved string clamp, a new tip riser having integrated, threaded height adjustment, an adjustable throat riser carried by an internal sliding bar having improved position lock, and machine height adjustment by a foot operated mechanism.

Abstract: Racquetball racquet having a frame forming a head and a handle characterized by a side profile comprising two intersecting arcs having different radii of curvature and intersecting at a point of intersection which is in the region of but above the throat of the racquet. These two arcs define two oppositely tapered frame segments. The first frame segment extends from the tip of the racquet, where the frame height is at a maximum, to the point of intersection, where the frame height is at a minimum. The second frame segment extends from the handle, at or below the throat, to the point of intersection. The arc defining the first segment is of much larger radius of curvature than the arc defining the second segment. This affords a maximum frame cross-sectional area at the tip and a smaller frame cross-sectional area in a flex zone which includes the point of intersection.

Abstract: A toggle action string clamp for a racquet stringing machine comprises two vise members movable along positioning glide bars attached to the stringing machine, which can be locked to the bars and to the strings of a racquet positioned in the machine. An angular link member connects a bottom vise member to a clamp-locking handle, with the top vise member being located therebetween. Locking is achieved by forcing the bottom U-shaped portion of the handle against a locking pin contained in the top vise member, thereyby urging the two vise members together. The clamp is provided with a wedge block mechanism capable of adjusting the effective distance between the bottom of the U-shaped portion and the bottom vise member, thus controlling the clearance between the vise members and, therefore, the clamping force.

Abstract: The present invention comprises a graphite composite racquet frame having a particular structure that provides internal and external shock absorption. The internal shock absorption is provided by a core material having high impact strength such as an aromatic aramid. External shock absorption is provided by a fiber reinforced plastic wrapping. The shock absorption elements allow graphite fibers to be used for construction of racquets which are commonly subject to a great deal of physical abuse such as racquetball racquets.

Abstract: The improved racquet has a strung surface which is larger in area than the strung surface of a conventional racquet, and in which the strung area is both longer in length and width than the strung area of a conventional racquet. However, the overall weight and balance of a conventional racquetball racquet which have proven necessary for good playing characteristics for all such racquets have been maintained. The racquet has synergistically combined the weight of the racquet, the center of mass of the racquet, the stiffness of the frame, and the response characteristics to create a racquet of sufficient durability with a larger "sweet spot" to facilitate the playing of the sport and to increase the level of skill, particularly of the novice and intermediate players.

Abstract: A molded composite racquet is provided, wherein the frame of the entire racquet is prepared using the combination of continuous graphite fibers longitudinal within the shape of the frame, wrapped in a bias arrangement with layers of fiberglass, that combination being covered by a protective resinous outerlayer. The presence of the graphite fiber in a unidirectional orientation around the hoop of the racquet in the plane of the strings increases the resistance against compression with minimal affect on the flexibility, bending or torsion, of the racquet. The concentric and bias orientation of the fiberglass layer supplies sturdiness to increase the resistance to torsion and bending stress. The molded composite racquet achieves a controlled impulse duration during impact with a game ball which provides greater control during impact and less shock to the user of the racquet during the recreation.

Abstract: A steel tubular frame design for racquetball racquets, has a varying cross-sectional structure. This structure gives strength in the lower portion of the racquet so as to reduce the torsional and flexional movements of the frame in that area and has a different cross-sectional area in the upper portion of the racquet where flexibility is needed, providing this flexibility in a continuous one-piece racquet. The invention is characterized by a four-sided peanut-shaped steel tube that has convex corners and two concave sides on the long sides. The convexity and concavity varying at different points throughout the racquet. The racquet frame is of a quadraform/wishbone configuration and is throatless.

Abstract: A racket stringing machine utilizing an improved retaining standard for securing a racket to be strung in a fixed position. The retaining standard includes a vise portion and a clamp portion. The clamp portion has an attached rod that fits into a hole in the vise. The clamp portion serves to maintain the racket to be strung in a fixed position on the vise. The vise also includes a slot into which a dog is inserted. The dog bears against the clamp rod and fixes it in a particular location. A handle having a cam portion is also provided. The cam portion of the handle engages the dog so as to allow selective engagement with the clamp rod. Additionally, frame retainers of different sizes and shapes are provided that allow rackets of various configurations to be strung with the same stringing machine.

Abstract: The improved racquetball racquet has a strung surface which is larger in area than the strung surface of a conventional racquet, and in which the strung area is both longer in length and width than the strung area of a conventional racquet. However, the overall weight and balance of a conventional racquetball racquet which have proven necessary for good playing characteristics for all such racquets have been maintained. The racquet has synergistically combined the weight of the racquet, the center of mass of the racquet, the stiffness of the frame, and the response characteristics to create a racquet of sufficient durability with a larger "sweet spot" to facilitate the playing of the sport and to increase the level of skill, particularly of the novice and intermediate players.

Abstract: A racquetball racquet having a metal frame is disclosed, wherein increased stiffness in the metal frame is provided by a grooved contact between the inner surfaces of the frame comprising the outer perimeter of the racquet and a throat piece, completing the reinforced enclosure within which the strings are arranged. This grooved contact of the throat piece with the metal frame further resists the stress and strain of contact between the racquet and the racquetball, such that the entire surface of the strings behaves in a uniform and predictable fashion.

Abstract: This invention is directed toward making hollow racquet ball balls. This is accomplished by molding a mass of vulcanizable elastic material to hollow semi-spherical form and heating the bulk of the material substantially fully to vulcanize it while simultaneously cooling a portion around the full edge so it is only partially vulcanized at the edge area thereof. Then two of such semi-spherical forms have the edges thereof abutted under some pressure to force the uncured edges together, and heat is then applied to the uncured edges of each half to fully vulcanize them and bind them together to form a unitary seamless ball thereform.Apparatus for forming the balls includes mold means defining a hollow semi-spherical cavity with a cooling chamber being provided at the open edge of the cavity that defines an edge of the formed hollow half sphere whereby a cooling medium can be circulated at the edge to prevent vulcanization thereof while the remaining part of the hollow half sphere is heated and vulcanized.

Abstract: The improved racquetball racquet has a strung surface which is larger in area than the strung surface of a conventional racquet, and in which the strung area is both longer in length and width than the strung area of a conventional racquet. However, the overall weight and balance of a conventional racquet which has proven necessary for good playing characteristics for all such racquets have been maintained. The racquet has synergistically combined the weight of the racquet, the center of mass of the racquet, the stiffness of the frame, and the response characteristics to create a racquet of sufficient durability with a larger "sweet spot" to facilitate the playing of the sport and to increase the level of skill, particularly of the novice and intermediate players. The racquet has an overall length of 181/2 inches to 221/2 inches and a .Iadd.frame and strung surface .Iaddend.width of .[.12.]. .Iadd.91/2 .Iaddend.inches to .[.143/4.]. .Iadd.111/2 .Iaddend.

Abstract: The improved racquet has a strung surface which is larger in area than the strung surface of a conventional racquet, and in which the strung area is both longer in length and width than the strung area of a conventional racquet. However, the overall weight and balance of a conventional racquetball racquet which have proven necessary for good playing characteristics for all such racquets have been maintained. The racquet has synergistically combined the weight of the racquet, the center of mass of the racquet, the stiffness of the frame, and the response characteristics to create a racquet of sufficient durability with a larger "sweet spot" to facilitate the playing of the sport and to increase the level of skill, particularly of the novice and intermediate players. The racquet has an overall length of .[.181/2.]. .Iadd.19 .Iaddend.