Patents by Inventor Duane Charles John

Duane Charles John has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080146372
    Abstract: The present invention is an improved putter that assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The shaft is attached to the clubhead such that it can swivel from a practice configuration to a play configuration. The putter also comprises a hosel with an attached alignment cap having lobes which matingly engage a series of recesses on the clubhead to secure the clubhead to the shaft. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for either a right or left-handed stroke.
    Type: Application
    Filed: February 19, 2008
    Publication date: June 19, 2008
    Inventor: Duane Charles John
  • Patent number: 7374500
    Abstract: The present invention is an improved putter that assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The shaft is attached to the clubhead such that it can swivel from a practice configuration to a play configuration. The putter also comprises a hosel with an attached alignment cap has lobes which matingly engage a series of recesses on the clubhead to secure the clubhead to the shaft. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for either a right or left-handed stroke.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: May 20, 2008
    Inventor: Duane Charles John Engdahl
  • Patent number: 7041004
    Abstract: The present invention is an improved putter that combines several features to provide a balanced putter, which assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The shaft is attached to the clubhead such that it can swivel from a practice configuration to a play configuration. The clubhead has tapered top and bottom surfaces such that the angle of the shaft relative to the sole of the putter is no more than 80 degrees. The clubhead has a playing surface on one face that is parabolic and can be flat in the extreme. The clubhead has a practice surface on the other face that is curved, preferably elliptical, to assist the golfer in learning the proper stroke. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for either a right- or left-handed stroke.
    Type: Grant
    Filed: August 16, 2004
    Date of Patent: May 9, 2006
    Inventor: Duane Charles John Engdahl
  • Patent number: 6776727
    Abstract: Several features are combined to provide a balanced putter, which assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The clubhead is substantially symmetric around the shaft and has tapered top and bottom surfaces such that the angle of the shaft relative to the sole of the putter is no more than 80 degrees. The shaft is attached at the center of the clubhead, and the clubhead and shaft are arranged so that the center of gravity of the clubhead strikes the center of the golf ball. The clubhead has a playing surface on one face that is parabolic and can be flat in the extreme. The clubhead has a practice surface on the other face that is curved, preferably elliptical, to assist the golfer in learning the proper stroke. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for a right- or left-handed stroke.
    Type: Grant
    Filed: January 23, 2003
    Date of Patent: August 17, 2004
    Inventor: Duane Charles John Engdahl
  • Publication number: 20040147332
    Abstract: Several features are combined to provide a balanced putter, which assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The clubhead is substantially symmetric around the shaft and has tapered top and bottom surfaces such that the angle of the shaft relative to the sole of the putter is no more than 80 degrees. The shaft is attached at the center of the clubhead, and the clubhead and shaft are arranged so that the center of gravity of the clubhead strikes the center of the golf ball. The clubhead has a playing surface on one face that is parabolic and can be flat in the extreme. The clubhead has a practice surface on the other face that is curved, preferably elliptical, to assist the golfer in learning the proper stroke. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for a right- or left-handed stroke.
    Type: Application
    Filed: January 23, 2003
    Publication date: July 29, 2004
    Inventor: Duane Charles John Engdahl