Patent Publication Number: US-7594861-B2

Title: Direct flex

Description:
BRIEF SUMMARY OF THE INVENTION 
   The current invention is installed within a hollow shaft golf club and acts on the shaft without using the shaft as part of its own structure. By design it engages the shaft at three points beginning with the handle and a second point and then a lower region of the shaft on one side only. The club shaft is allowed to flex away from the distal end of the insert but engages the spring action and rigidity of the insert as any force attempts to flex the shaft toward the distal contact point. The forces given major consideration are the inertia of the club shaft end and head as a golfer begins a downward swing toward the ball which tends to bend the shaft and head away from the swing, the forces at impact and the brief time of actual contact with the golf ball. Inserts with differing rigidity and the index able retainer allow customization of the affects of the insert. The insert may be installed in the handle end of the shaft without permanent modification of the shaft. Different materials and conditions of materials which affect modulus of elasticity and variations of profiles of the insert may be implemented in keeping with the three contact point design. Embodiments which give lighter spring action may be shaped to give a preload affect upon insertion into the club shaft to further vary to possible adjustability. Those skilled in the art can envision several arrangements to mount the proximal end of the insert in the open end of the club shaft opposite the head. It would also be apparent to those skilled in the art to provide an indexing means relative to the turning bar or the stop ring to the shaft in order for the user to have a position reference for adjusting the radial position of the tension rod. 
   The preferred embodiment as shown in the drawings is a tension rod  9  with two bends mounted in a turning bar  7 . Turning bar  7  has a central aperture to receive tension rod  9 , a turning slot (depression)  12 . Stop ring  5  has an outer profile that matches the internal profile of the open end opposite the head of the subject golf club shaft  3 . An outer lip  6  helps retain the stop ring at the top of club shaft  3 , index marks  10  for a radial position reference to turning bar  7  and inside lip (stop ledge aperture)  8  to help retain turning bar  7  from falling inside club shaft  3 . Stop ring  5  is mounted inside club shaft  3 &#39;s handle end opposite the head by a stop ring securing means and turning bar  7  with tension rod  9  is placed inside it to hold its position as referenced by indicator mark  11  and index marks  10  for adjustment. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       FIG. 1 . shows a hollow shaft golf club. 
       FIG. 2 . shows a cross section view of the handle end of the club shaft. 
       FIG. 3 . shows a cross section view of the middle area of the club shaft. 
       FIG. 4 . shows a cross section view of the lower area of the club shaft. 
       FIG. 5 . shows a top view of the handle end of the club shaft. 
       FIG. 6 . shows a side view of the turning bar. 
       FIG. 7 . shows a side view of the stop ring. 
       FIG. 8 . shows a side view of the tension rod. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 . shows golf club  1  including head  2 , shaft  3  and handle  4 . Cross sections  2 ,  3  and  4  are indicated. 
     FIG. 2 . shows a cross section view of the handle end of golf club  1 . Stop ring  5  is mounted inside club shaft  3  and rests on outer lip  6  and engages club shaft  3 . Turning bar  7  is installed in stop ring  5  and rests on inside lip  8  and engages stop ring  5 . Tension rod  9  is fixedly engaged in the center of turning bar  7  and extends downward in club shaft  3 . Stop ring  5  outer lip  6  locates stop ring  5  at the top of club shaft  3 . 
     FIG. 3 . shows a cross section view of club shaft  3  below handle  4  where tension rod  9  engages shaft  3 . 
     FIG. 4 . shows a cross section view of club shaft  3  where the distal end of tension rod  9  engages shaft  3 . 
     FIG. 5 . shows top view of golf club  1  with stop ring  5  and turning bar  7  installed. Club shaft  3  is obscured by the outer lip  6  of stop ring  5  however club handle  4  is shown. Turning bar  7  is mounted in stop ring  5 . tension rod  9  is fixedly mounted in turning bar  7 . Stop ring  5  also has index marks  10  used to indicate its position relative to indicator mark  11  on turning bar  7 . The top view of tension rod  9  is shown in conjunction with turning slot  12 . 
     FIG. 6 . shows a side view of turning bar  7 . 
     FIG. 7 . shows a side view of stop ring  5  with external lip  6 . 
     FIG. 8 . shows tension rod  9  which has a curvealinear shape so that it engages the turning bar in the center of club shaft  3  and two other locations. 
   The disclosed preferred embodiment is illustrative and not intended to limit those skilled in the art as they can envision alternate embodiments which give equal function. 
   U.S. Pat. No. 6,241,623 issued to Laibangyang in 2001 discloses a golf club shaft flex modifying system which basically consists of a variable tensioned centrally mounted wire with anchors at each end of the shaft. The apparent novelty of 623 is that it enables the player to readily adjust the tension while playing. Also present are a plurality of wire supports spaced in the shaft to help maintain the wire&#39;s centricity during any flexure. Increasing the tension on the central wire tends to exert a compressive force on the shaft section between the anchors thereby modifying the characteristics of the shafts reaction to force exerted by the swing and impact with the golf ball. Again, unlike the present invention 623 modifies the flex characteristics of the shaft at all radial angles and requires a distal anchor that may not be readily removable. 
   U.S. Pat. No. 6,394,909 also issued to Laibangyang in 2002 discloses a golf club shaft flex modifying system which is very similar to 623. 909 further discloses and claims a tensioned wire and an embodiment includes the central tensioned wire of flat cross section accommodated by the anchor ends. This embodiment further includes wire supports with a slot shaped bore. 623 and 909 both utilize the shaft itself a structural members of the flexure modifying system. 
   The current invention acts on the shaft without using the shaft as part of its own structure. Due to its generally three contact point shape it engages the lower end of the shaft on one side only. The distal end of the shaft would be allowed to flex away from the insert but engage the rigidity of the insert as any force attempted to flex the shaft toward the distal contact point. The forces given major consideration here are the inertia of the distal end of the shaft and head as a golfer begins a swing which tends to bend the shaft and head away from the swing and the forces at the moment of impact with the golf ball. Inserts with differing rigidity and an index able retainer allow customization of the affects of the insert. The insert may be installed in the proximal handle end of the shaft without modification of the shaft which may be returned to its prior condition.