Abstract: A seamless hollow rubber core for a tennis ball is formed within a spherical cavity of a mold, wherein the spherical cavity has a diameter commensurate with the outside diameter of the core. A spherical surface is formed from a material which has a melting temperature above the curing temperature of the rubber compound used for the core. The spherical surface is dimensioned commensurately with the inside diameter of a core. The spherical surface is then mounted within the mold concentrically with the spherical cavity. Unsured rubber core preforms are placed about the spherical surface in intimate contact with the spherical cavity. The core performs are then heated to a curing temperature. During the curing process, the preforms meld to form the seamless core. The core just formed is then heated to the melting temperature of the material of the spherical surface so that the spherical surface melts thereby leaving molten within the core.

Abstract: A method of making tennis balls by a single core part and fabric piece bonding step is disclosed wherein an assembly of core parts, including a pair of hemispheric core halves, and fabric cover pieces, including a pair of figure eight fabric dumbbells, are assembled to one another to a subassembly of core parts held together by a dried but uncured first curable cement, the fabric pieces are held about the core subassembly by a second dried but uncured cement and a third curable cement is provided between the fabric pieces to form the exterior ball seam. The assembly of core and cover parts and pieces thus held together by the tackiness of dried but uncured cements is then placed within a snugly fitting mold and cured in the presence of heat to bond the core parts to one another, the fabric cover pieces to the core and the fabric piece edges to one another to a completed ball.

Abstract: An improved method of making a fabric covered tennis ball is disclosed wherein a pair of molded semi-hemispheric elastomeric material core halves are joined together by a thermosetting adhesive means, the joining of the core halves taking place in the presence of atmospheric pressure. Heat and pressure are applied externally to the core halves to cure and set the adhesive, and in a preferred embodiment to localize areas, particularly where the adhesive resides between the core halves. An integrally molded air valve is provided in a side wall of one of the core halves to facilitate the introduction of additional air pressure into the core after its having been bonded in assembled condition. A tennis ball fabric covering is provided about and adhesively secured to the core covering the air valve, the fabric being air permeable to allow introduction of additional amounts of air into the completed tennis ball to facilitate production of a desired ball bounce characteristic for the tennis ball.

Abstract: A normally closed duckbill valve for controlling the direction of fluid flow in a fluid-conducting conduit and a method of manufacturing the valve are provided. The valve is formed of elastomeric material and comprises a generally cylindrical body member provided with an axial fluid passageway having an inlet end and an outlet end provided with an outlet slit, and progressively narrowing in cross-section from the inlet end to the outlet end to define a pair of opposed sealing lips at the outlet slit. Means for normally urging the sealing lips into a closed position are provided and comprise widened lip margins disposed at opposite ends of the outlet slit. The valve is formed by molding the elastomeric material into the preferred shape and then providing the widened lip margins with a closing bias by causing a greater amount of shrinkage in the lip margins, relative to the remaining portions of the sealing lips, during curing of the molded material from an elevated curing temperature to room temperature.

Abstract: A pump mechanism primarily designed for use in sealing and pressurizing a container for tennis balls and the like. An alternate embodiment is adaptable for use in pressurizing items such as game balls and air-inflated shock absorbers and forks as used on motorcycles. The pump has a cylinder with a one-way valve at the outlet end. A piston is provided for moving longitudinally in and out of the cylinder to provide the pumping action. The piston is hollow and contains a second, spring-biased piston therein. The side wall of the piston contains a relief channel or hole at a pre-set distance from the bottom thereof. As the pressure in the pump increases, the piston within the piston is forced back against the increasing bias of the spring. When the biased piston moves sufficiently to expose the outlet channel or hole, the pressure limit of the pump is reached as any additional pressure is vented therefrom.

Abstract: An improved tennis ball having an integrally molded valve in the sidewalls thereof for assuring constant pressure within the ball and, therefore, constant playing characteristics. The valve is characterized by being of unitary construction and having a normally open and a normally closed portion. The valve is constructed of a tapered deformable elastomeric material such that the normally closed portion seals the ball against low initial internal pressures sufficiently to allow the internal pressure within the ball to deform the normally opened portion into wedged engagement with the passageway through the wall of the ball containing the valve. As thus configured, increased internal pressure wedges the normally opened portion increasingly tightly into the passageway to provide a tight seal which is resistant to opening upon impact of the ball. The normally opened portion is provided with knife edges and a polished surface on the interior to provide leak-free sealing.

Abstract: An improved check valve is disclosed primarily for use in game balls such as tennis balls, racquet balls, footballs, basketballs, and the like. The valve is adapted for molding into the shell of the game ball upon initial manufacture or for insertion therein as part of a valve insert subsequent to manufacture. The valve is characterized by being of unitary construction and having a normally open and a normally closed portion. The valve is constructed of a tapered deformable elastomeric material such that the normally closed portion seals the ball against low initial internal pressures sufficiently to allow the internal pressure within the ball to deform the normally open portion into wedged engagement with the passageway through the wall of the ball. As thus configured, increased internal pressure wedges the normally open portion increasingly tightly into the passageway to provide a tight seal which is resistant to opening upon impact of the ball.

Abstract: An inflatable game ball having an outer shell of rubber or rubber-like elastomer, enclosing a hollow interior space, with an internal self-sealing check valve extending through the shell. The check valve is molded of soft rubber and has a pair of thin flanges or lips, arranged side-by-side, with one or more openings that are opened up to allow air to pass freely into the ball when the air pressure on the outside of the valve is greater than the pressure inside the ball. A hand pump is provided, which has a nozzle that inserts into the outside opening of the check valve, and operating the pump causes air to be pumped into the ball to inflate the latter to the desired pressure. The thin flanges of the check valve are closed tightly against one another by the air pressure within the ball, thereby sealing the valve opening to prevent escape of the air.