Variable length shaft
A variable length golf club shaft is disclosed herein. The variable length shaft includes a hollow lower shaft with a plurality of holes, a hollow upper shaft with at least one protrusion extending from an inner surface that is sized to fit within the plurality of holes, and an unlocking bar. The shaft length can be adjusted by sliding the upper shaft over the lower shaft and using the unlocking bar to release the protrusion from the holes to allow overall shaft length adjustments. in another embodiment, the variable length shaft includes a hollow lower shaft, a hollow upper shaft, an engaging insert, and a locking bar.
1. A variable length shaft comprising:
a hollow upper shaft comprising a wall having a plurality of holes;
a hollow lower shaft comprising a wall having a plurality of holes;
a hollow engaging insert comprising an expanding portion having at least one protrusion sized to fit within one or more of the plurality of holes on each of the upper shaft and lower shaft;
a grip; and
a locking bar,
wherein the engaging insert is disposed within the upper shaft,
wherein the upper shaft is sized to slidably receive the lower shaft,
wherein a portion of the lower shaft is disposed between a portion of the upper shaft and a portion of the engaging insert, and
wherein inserting the locking bar into the engaging insert causes the expanding portion to expand, the at least one protrusion to engage with at least one of the plurality of the holes on each of the upper shaft and the lower shaft, and the portion of the tower shaft to press against the portion of the upper shaft.
2. The variable length shaft of claim 1 , wherein each of the upper shaft and the lower shaft comprises a longitudinal axis, and the plurality of holes on each of the upper shaft and the lower shaft are arranged along the longitudinal axes of the upper shaft and the lower shaft.
3. The variable length shaft of claim 1 , wherein the plurality of holes on the lower shaft comprises at least ten holes each on at least two opposing sides of the lower shaft wall, and wherein the plurality of holes on the upper shaft comprises at least three holes each on at least two opposing sides of the upper shaft wall.
4. The variable length shaft of claim 1 , wherein the engaging insert comprises two prongs, wherein each of the prongs comprises at least one protrusion, and wherein the prongs are pulled toward each other by an expandable band.
5. The variable length shaft of claim 4 , wherein inserting the locking bar into the engaging insert stretches the expandable band and pushes the prongs away from each other.
6. The variable length shaft of claim 4 , wherein the expandable hand is composed of a material selected from rubber and urethane.
7. The variable length shaft of claim 1 , wherein each of the upper shaft, lower shaft, engaging insert, and locking bar is composed of a composite material.
8. The variable length shaft of claim 1 , wherein the grip is affixed to an external surface of the upper shaft.
9. The variable length shaft of claim 1 , further comprising a weighted cap, wherein the upper shaft comprises an opening at an upper end and an opening at a lower end, wherein the opening at the lower end receives the lower shaft, and wherein the opening at the upper end receives the weighted cap.
10. The variable length shaft of claim 1 , wherein sliding the upper shaft along the tower shaft adjusts an overall length of the variable length shaft, and wherein the variable length shaft allows for overall length adjustment in the range of 3 inches.
11. The variable length shaft of claim 1 , wherein the upper shaft comprises a slit along a longitudinal axis to accommodate sliding along the lower shaft, and wherein the lower shaft comprises a locating clip that mates with the slit and prevents the upper shaft from twisting when it slides along the lower shaft.
12. The variable length shaft of claim 1 , wherein the lower shaft piece comprises an exterior surface having at least one length marking.
13. The variable length shaft of claim 1 , wherein the engaging insert is fixed within the upper shaft with an adhesive.
14. The variable length shaft of claim 1 , wherein the engaging insert comprises a locking and wherein the locking pin fixes the engaging insert within the upper shaft.
15. The variable length shaft of claim 14 , wherein the locking pin protrudes from an upper shelf portion of the engaging insert.
16. The variable length shaft of claim 15 , wherein the upper shelf portion rests against an open upper end of the upper shaft, and wherein the locking pin engages a locking hole located proximate the open upper end.
17. The variable length shaft of claim 1 , wherein the locking bar is a hollow tube.
18. The variable length shaft of claim 17 , wherein the locking bar comprises an upper opening and internal threads located proximate the upper opening.
19. The variable length shaft of claim 18 , further comprising a tool, wherein the tool comprises external threads sized to mate with the internal threads, and wherein the external threads removably connect the tool to the locking bar.
20. The variable length shaft of claim 19 , wherein the tool comprises a handle.