Striking implement with improved energy storage and vibration dampening properties

• US 6,625,848 B1
• Filed: 10/05/2000
• Issued: 09/30/2003
• Est. Priority Date: 10/12/1999
• Status: Expired due to Fees

• Current Assignee: Terry L. Schneider
• Original Assignee: Terry L. Schneider
• Inventors: Schneider, Terry L.
• Primary Examiner(s): Knight, Anthony
• Assistant Examiner(s): Hutton, Doug
• Application Number:
  US09/680,556
• Time in Patent Office: 1,090 Days
• Field of Search: 164/36, 81/22, 811/771, 814/89, 819/00, 745/43, 745/511, 473/289, 473/282, 473/287, 473/296, 473/316, 473/520, 473/564
• US Class Current: 16/436
• CPC Class Codes: A01B 1/02 Spades; Shovels hand-operated dredgers E02F3/02
• CPC Class Codes: A63B 2102/02 Tennis
• CPC Class Codes: A63B 2102/06 Squash
• CPC Class Codes: A63B 2102/18 Baseball, rounders or similar games
• CPC Class Codes: A63B 2102/24 Ice hockey
• CPC Class Codes: A63B 2102/32 Golf
• CPC Class Codes: A63B 2102/36 Croquet
• CPC Class Codes: A63B 2209/02 with reinforcing fibres, e.g. carbon, polyamide fibres
• CPC Class Codes: A63B 49/02 Frames
• CPC Class Codes: A63B 59/50 Substantially rod-shaped bats for hitting a ball in the air, e.g. for baseball
• CPC Class Codes: A63B 59/60 of mallet type, e.g. for croquet or polo
• CPC Class Codes: A63B 59/70 with bent or angled lower parts for hitting a ball on the ground, on an ice-covered surface, or in the air, e.g. for hockey or hurling
• CPC Class Codes: A63B 60/0081 Substantially flexible shafts; Hinged shafts
• CPC Class Codes: A63B 60/06 Handles
• CPC Class Codes: A63B 60/08 characterised by the material
• CPC Class Codes: A63B 60/10 with means for indicating correct holding positions A63B60/12 takes precedence
• CPC Class Codes: A63B 60/54 with means for damping vibrations
• CPC Class Codes: B25G 1/01 Shock-absorbing means B25G1/02 takes precedence

Abstract

Striking implements that have an improved ability to store and quickly release significant energy during flexure and at the same time have significant vibration damping capability to impart a desired “feel” to the user. A shape memory alloy element is inserted at a specific flex point along the length of the sports or utility striking implement to permit a desired degree of flexure, with an enhanced leverage effect, and to absorb undesired vibrational energy. Typical sports or utility striking implements utilizing the invention include, but are not limited to, golf clubs, hockey sticks, polo clubs, tennis rackets, racket ball rackets, baseball bats, pole vaults, rowing oars, picks, axes, hammers, and the like.

Claims

1. A striking implement having improved energy storage and release capability, and vibration dampening, and having a flex point location, the implement comprising a shaft extending from a first end adapted for being grasped by a human hand to a second end affixed to an impactor for striking an object, the implement comprising:

an element comprised of a shape memory alloy material located at the flex point, the element extending coaxially along a portion of the shaft and flexing when a user strikes an object with the implement, wherein the shape memory alloy material has super-elastic properties and undergoes martensitic phase transformation to absorb forces generated when the impactor is employed to strike the object; and

wherein the shape memory alloy element has an elongate shape with an upper end and a lower end, the upper end of the element extending to within a first portion of the shaft, and the lower end of the element extending to within a second portion of the shaft, with a gap of predetermined size between the portions of the shaft.

2. The implement of claim 1, wherein the striking implement is selected from the group consisting of golf clubs, baseball bats, polo clubs, tennis racquets, squash racquets, racquet ball racquets, ice hockey sticks, vaulting poles, picks, hammers, and axes.

3. The implement of claim 1, wherein the shape memory alloy element is in the form of a hollow substantially cylindrical tube.

4. The implement of claim 1, wherein the shape memory alloy element comprises a solid plug of the alloy.

5. The implement of claim 4, wherein the solid plug is in the form of a substantially solid cylinder-shaped plug.

6. The implement of claim 1, wherein the shape memory alloy element is dimensionally sized such that when stressed during flexure, a stress level of the element is proximate a threshold of a pseudo-elastic region of a stress-strain property curve of the element.

7. The implement of claim 1, wherein the shape memory alloy element is in an austenitic phase at a temperature at which the implement is used.

8. The implement of claim 1, wherein the shape memory alloy element is affixed to the ends of the shaft with a composition composing an organic polymer.

9. The implement of claim 8, wherein the composition comprises a composite of epoxy resin and aramid fibers.

10. The implement of claim 9, wherein the composition is in the form of a substantially conical shaped plug, a substantially conical shaped plug extending from each of the upper end of the lower shaft portion and lower end of the upper shaft portion toward a central region of the shape memory alloy element and at least partially surrounding the element.

11. The implement of claim 1, wherein an upper end of the shape memory alloy element is restrained within the first portion of the shaft by a collar extending between the element and an inner wall of the shaft.

12. The implement of claim 1, wherein one end of the shape memory alloy element is restrained inside one of the shaft portions by a collar extending from the element to a wall of the one shaft portion;

and an opposite end of the element is encased in a polymeric plug, the plug forming a bridge between ends of the first and second shaft portions.

13. The implement of claim 1, wherein an upper end of the element is restrained substantially immovable within the first shaft portion, and the lower end of the element is mounted substantially immovable within the second shaft portion.

14. The implement of claim 13, wherein an end of each of the first and second shaft portions, respectively, have affixed thereto a coupling, each coupling mounted to an end of the respective shaft portion, to a second end tapering inward to surround an outer surface of the shape memory alloy element proximate a center of the element, the second ends of the couplings spaced apart by a predetermined distance.

15. The implement of claim 1, wherein an upper end of the shape memory alloy element is contained within a wall of the first shaft portion and a lower end of the element is contained within a wall of the second shaft portion, a central portion of the element is not contained within walls of the shaft and the central portion flexes when the implement is used to strike an object.

16. The implement of claim 15, wherein the upper end of the shape memory alloy element is at least partially encased in a polymeric plug, the plug adhering to an inner wall of the first shaft portion.

17. The implement of claim 15, wherein the lower end of the shape memory alloy element is at least partially encased in a plug, the plug adhering to an inner wall of the second shaft portion.

18. The implement of claim 1, wherein the element comprises a bundle of wires.

19. A shaft of a striking implement comprising:

(a) a first shaft portion having a first end;

(b) a second shaft portion having a second end, the second end and the first end separated by a gap of predetermined size; and

(c) a shape memory alloy element spanning the predetermined gap and extending from the first shaft portion to the second shaft portion, wherein the shape memory alloy element has super-elastic properties and undergoes an austensitic to martensitic phase transformation under flexure to dampen vibrations generated when the striking implement is employed to strike an object.

20. The shaft of claim 19, wherein the shape memory alloy element is elongate, with a longitudinal axis aligned with a longitudinal axis of the shaft.

21. The shaft of claim 19, wherein the shape memory alloy element comprises a first end surrounded by a polymeric plug, the plug affixed to an inner wall of the first shaft portion.

22. The shaft of claim 21, wherein the polymeric plug is substantially cylindrical.

23. The shaft of claim 21, wherein the polymeric plug is frusto-conically shape.

24. The shaft of claim 19, wherein the shape memory alloy element has a first end contained within an inner surrounding wall of the first shaft portion, the first end restrained by a collar extending from the element to an inner wall of the first shaft portion.

25. The shaft of claim 24, wherein the shape memory alloy element comprises a second end, the second end at least partially encased in a polymeric plug, the plug adhered to an inner wall of the second shaft portion.

26. The shaft of claim 25, wherein the plug adheres to the inner wall of the first shaft portion, and spans the gap between the two shaft portions.

27. The shaft of claim 26, wherein a portion of the plug spanning the gap comprises a circumferential notch adjacent the gap between the first and second shaft portions.

28. The shaft of claim 19, wherein the shape memory alloy element comprises a second end, the second end at least partially encased in a polymeric plug, the plug adhered to an inner wall of the second shaft portion.

29. The shaft of claim 28, wherein the plug adheres to the inner wall of the first shaft portion, and spans the gap between the two shaft portions.

30. The shaft of claim 29, wherein a portion of the plug spanning the gap comprises a circumferential notch, the notch located in the gap between the first and second shaft portions.

31. The shaft of claim 19, further comprising:

a frusto-conical shaped first coupling mounted to the first end of the first shaft portion; and

a frusto-conical shaped second coupling mounted to the second end of the second shaft portion;

apexes of the couplings surrounding the shape memory alloy element.

32. The shaft of claim 31, wherein the first end of the element is restrained within the first shaft portion by a collar extending to an inner wall of the shaft.

33. The shaft of claim 19, wherein the shaft portion ends are tapered, the element extending coaxially with the shaft portions and held within tapered ends of the shafts.

34. The shaft of claim 33, wherein the tapered ends are adhered to the element.

35. The shaft of claim 33, wherein the tapered ends hold the element by friction.

36. A striking implement comprising a shaft, the shaft comprising:

(a) a first shaft portion having a longitudinal axis and a first end;

(b) a second shaft portion having a longitudinal axis and a second end;

(c) a shape memory alloy element intermediate the first and second shaft portions, the alloy having a longitudinal axis coincident with longitudinal axes of the first and second shaft portions, the element bridging a gap between ends of the shaft portions; and

(d) a stop, the stop limiting flexure of the element, when the implement strikes an object, to an amount less than would result in permanent deformation of the element, wherein the shape memory alloy element has super-elastic properties and undergoes an austensitic to martensitic phase transformation under flexure to dampen vibrations generated when the implement is employed to strike the object.

37. The implement of claim 36, wherein the shape memory element comprises a first end surrounded by a polymeric plug, the plug affixed to an inner wall of the first shaft portion.

38. The implement of claim 37, wherein the polymeric plug is substantially cylindrical in shape.

39. The implement of claim 37, wherein the polymeric plug is frusto-conical in shape.

40. The implement of claim 36, wherein the shape memory alloy element has a first end surrounded by an inner wall of the first shaft portion, the first end restrained by a collar extending from the element to an inner wall of the shaft portion.

41. The implement of claim 40, wherein the shape memory alloy element comprises a second end, the second end at least partially encased in a polymeric plug, the plug adhered to an inner wall of the second shaft portion.

42. The implement of claim 41, wherein a portion of the plug spans the gap and the plug comprises a circumferential notch adjacent the gap, between the first and second shaft portions.

43. The implement of claim 36, further comprising:

a frusto-conical shaped first coupling mounted to the first end of the first shaft portion; and

a frusto-conical shaped second coupling mounted to the second end of the second shaft portion;

apexes of the couplings surrounding the shape memory alloy element.