Weight secured by expansion element in golf club shaft
OwnerJohn Johnsoninventor
Life of this patent
Estimating the term…
Abstract
A golf club counter-weighting system, viable for both original manufacture and after-marketing, features an expandable weight assembly that is easily installed at a designated location within a golf club shaft and expanded via a user tool so as to become reliably secured in place by frictional pressure against the surrounding shaft. In a primary embodiment, the weight assembly is made to be threadedly engagable by the opposite end of a dual-function user tool enabling the weight assembly, when unexpanded, to be conveniently moved axially for initial installation, relocation and/or removal.
Claims17
A golf club weighting system for adding a desired amount of swing weight at a designated axial location in a hollow shaft of a golf club equipped with a grip, the system being viable in original manufacture, in after-marketing and in user golf play, implemented by a weight assembly comprising:
- a cylindrical rigid weight element, located coaxially in the hollow shaft, having an outside diameter made smaller than the shaft's inside diameter so as to provide a designated inherent peripheral clearance therebetween;
- a cylindrical expansion element, located coaxially in the hollow shaft beneath said weight element and attached thereto, having an inherent unexpanded outside diameter made smaller than the shaft's inside diameter so as to provide a designated inherent peripheral clearance dimension therebetween whenever said expansion element remains unexpanded;
- and
- an expansion subsystem in said weight assembly, including a machine screw that is drivable by a user expansion tool to clamp said resilient expansion element against said weight element so as to causing axial compression in said expansion element that translates into radial expansion exerting compressive contact against the surrounding shaft, thus applying thereto a frictional force that that can be increased by the user until said weight assembly becomes positively and reliably secured in place by frictional pressure against the surrounding shaft, thus ensuring fully satisfactory golf play with a desired amount of swing-weight added at the designated axial location.
A method of adding swing weight to be frictionally secured in place at a designated location in a hollow shaft of a golf club, viable in original manufacture, in after-marketing and in user golf play, comprising the steps of:
- (a) attaching a location tool to a weight assembly comprising a weight element held together against an unexpanded resilient expansion element by a machine screw with a screw-head made drivable by an expansion tool;
- (b) deploying the location tool to insert the weight assembly to a designated location in the shaft;
- (c) detaching and withdrawing the location tool from the shaft;
- (d) inserting the expansion tool into the shaft and into driving engagement with the screw-head;
- (e) rotating the screw clockwise by the expansion tool to pressurize and expand the expansion element so as to apply increasing pressure force peripherally against the surrounding shaft until the weight assembly has been frictionally secured in place;
- and
- (f) withdrawing the expansion tool from the shaft.
A method of adding a weight assembly within a hollow shaft of a grip-equipped golf club at a designated location restricted to an uppermost portion of the shaft, secured in place by the combination of (1) an expansion element capable of frictionally engaging the shaft and (2) a cap portion atop the weight assembly, threadedly engaging the grip, viable in original manufacture, in after-marketing and in user golf play, comprising the steps of:
- (a) configuring the weight assembly including a cylindrical weight element, smaller in diameter than the shaft interior, combined with an overhead externally-threaded annular grip cap portion larger in diameter than the weight element, and an underlying resilient expansion element, deployable via a screw-head made accessible and engagable by a user expansion tool to be expanded radially so as to frictionally secure the weight assembly in place in the shaft;
- (b) configuring the grip with a top central grip opening sized and internally threaded to engage the cap portion;
- (c) inserting the weight assembly, unexpanded, through the grip [opening into the top of the shaft, until the cap portion is aligned for threaded attachment to the grip;
- (d) inserting a cap drive tool into engagement with a driving recess in the cap portion;
- (e) rotating the weight assembly, by the cap drive tool, to thread the cap portion fully into the grip thus placing the weight assembly in the designated uppermost location in the shaft;
- (f) removing the cap drive tool from the golf club;
- (g) inserting the expansion tool into engagement with the screw-head;
- (h) rotating the expansion tool and screw-head clockwise until the expansion element displaces the weight assembly axially in the shaft for purposes of installing, relocating and removing the weight assembly;
- and
- (i) removing the expansion tool from the golf club.
Dependencies are inferred from the claim text.