Acetal Patents (Class 273/DIG11)
  • Patent number: 4872684
    Abstract: A golf putter has a substantially cylindrical club head made from a tough, resilient, non-metallic plastic material such as acetal polymer (e.g., Delrin or Celcon); has weight-receiving receptacles recessed in each of the heel and toe ends; and weight inserts within the weight-receiving receptacles. The diameter of the cylindrical club head, e.g., one and one-quarter inches, is smaller than the diameter of a ball to be played. A visual alignment mark extends circumferentially partially around the cylindrical body at a position equidistant between the heel and toe ends and thus, just toward the toe end from the position at which a conventional shaft is coupled to the club head.
    Type: Grant
    Filed: December 23, 1988
    Date of Patent: October 10, 1989
    Inventor: Stephanie A. Dippel
  • Patent number: 4786055
    Abstract: An improved sports racquet is provided having elements placed between the outer edge of the frame and the strings. The elements prevent the strings from touching the outer edge of the frame and rotate in response to a force applied in a direction generally perpendicular to the strings, thereby expanding the sweet spot, providing improved playability of the racquet, and significantly reducing the fibration that is transferred to the player's arm. The elements are preferably spherical in shape and may be comprised of various materials, including acetal, plastic and metal. The elements preferably rest in receptacles in the racquet frame, which may be integral with the frame or separate pieces, such as sleeves or grommets, that are connected to the frame. The receptacles are preferably designed to have a surface with substantially the same curvature as the bottom surface of the elements.
    Type: Grant
    Filed: June 19, 1986
    Date of Patent: November 22, 1988
    Inventor: James P. Darling
  • Patent number: 4747598
    Abstract: The invention relates to a frame for a games racket e.g. tennis, of the type made as a hollow injection moulding of reinforced thermoplastics material. The frame has attachments for stringing in the form of a series of discrete lugs moulded integrally with the walls of the hollow frame and so positioned that the racket strings in their desired positions do not pass to the outer periphery of the head. The discrete lugs may for example be around the inner periphery of the head of the frame and each contain an integrally-moulded circumferential bore for string passage. The frame may be made by injection moulding around a fusible core and the shape of the core required to give the desired lugs provides strong resistance to movement under the injecting pressures hence giving improved product uniformity.
    Type: Grant
    Filed: June 26, 1985
    Date of Patent: May 31, 1988
    Assignee: Dunlop Limited a British Company
    Inventor: Michael E. Curtis
  • Patent number: 4498667
    Abstract: A process for forming a rubber or vinyl coated baseball or softball is comprised of supporting a baseball or softball core within a mold cavity to position the exterior of the core uniformly equidistant from the mold cavity wall to provide a space between the core exterior and the cavity wall. A thermoplastic rubber or plasticized vinyl resin is injected into the mold cavity to flow into and fill the space between the core and the wall. The thermoplastic rubber or plasticized vinyl resin is allowed to solidify and a rubber or vinyl coated baseball or softball is removed from the mold.
    Type: Grant
    Filed: April 12, 1979
    Date of Patent: February 12, 1985
    Assignee: Home of Champions, S.A.
    Inventor: Julius Tomar
  • Patent number: 4211407
    Abstract: Baseballs and softballs are comprised of a spherical core and a two-piece cover. The core consists essentially of a single spherical mass of partially blown ethylene vinyl acetate copolymer having 12 percent to 30 percent by weight of polymerized vinyl acetate units therein. Foam is in the center of the core which gradually reduces in cell size radially outwardly to a skin having a density substantially equal to the density of said copolymer.
    Type: Grant
    Filed: September 18, 1978
    Date of Patent: July 8, 1980
    Assignee: Home of Champions
    Inventor: Julius Tomar