Game racquet with separate head and handle portions for reducing vibration

Information

  • Patent Grant
  • 6500080
  • Patent Number
    6,500,080
  • Date Filed
    Friday, May 4, 2001
    23 years ago
  • Date Issued
    Tuesday, December 31, 2002
    21 years ago
Abstract
A game racquet includes separate head and handle portions which are separated by shock and/or vibration absorbing material. Both the head portion and the handle portion are bonded to the absorbing material and are thereby connected to each other.
Description




BACKGROUND




This invention relates to game racquets, and, more particularly, to a game racquet with separate head and handle portions which are separated by, and joined with, shock and/or absorbing material.




Game racquets such as tennis racquets, racquetball racquets, and squash racquets include a head portion and a handle portion. The head portion supports a string bed, and the player holds the racquet by the handle portion.




When the head portion strikes a ball, shock and vibration are transmitted from the head portion through the handle portion to the player's arm. Such shock and vibration can cause discomfort and can lead to physical problems such as tendinitis or tennis elbow.




Shock is caused by the impact of a ball on the strings. Shock on a typical tennis racquet might last about 3 milliseconds after ball impact.




Vibration is caused by shock and lasts longer. Vibration might last about 1000 milliseconds in a typical tennis racquet.




Many prior attempts have been made to reduce the transmission of shock and vibration to the player's arm. However, any direct connection between the head portion and the handle portion can provide an area through which shock and vibration can be transmitted. A conventional one-piece racquet acts as a conduit of vibration from the head to the handle.




U.S. Pat. No. 4,609,198 describes a racquet in which a tubular damping pad is positioned within the grip of the racquet.




SUMMARY OF THE INVENTION




The invention provides a game racquet with separate head and handle portions. The handle portion includes arms which extend along portions of the head, and the head and handle portions are separated by, and joined with, shock and/or vibration absorbing material such as urethane or rubber which reduces the transmission of shock and vibration from the head portion to the handle portion.




The head and handle portions are advantageously joined to the shock and/or vibration absorbing material by adhesive or an adhesive agent. If desired, an additional mechanical connection between the head and handle portions can be provided, for example, by strings which extend through string holes in both the head and the handle portions.




The shock and/or vibration absorbing material is advantageously urethane, natural rubber, butyl rubber, or synthetic rubber and has a Shore A hardness within the range of 0 to 90, more preferably within the range of 20 to 70, and most preferably within the range of 30 to 60. Other relatively soft polymeric materials could also be used.











DESCRIPTION OF THE DRAWING




The invention will be explained in conjunction with the attached drawing, in which





FIG. 1

is a front view of one embodiment of a game racquet which is formed in accordance with the invention;





FIG. 2

is a side view of the racquet of

FIG. 1

;





FIG. 3

is a front view of another embodiment of a racquet which is formed in accordance with the invention;





FIG. 4

is a side view of the racquet of

FIG. 3

;





FIG. 5

is a front view of the head portion of the racquet of

FIG. 3

;





FIG. 6

is a side view of the head portion of

FIG. 5

;





FIG. 7

is a front view of the handle portion of the racquet of

FIG. 3

;





FIG. 8

is a side view of the handle portion of

FIG. 7

;





FIG. 9

is a plan view of the strip of shock and/or vibration absorbing material which separates the head and handle portions of

FIGS. 5 and 7

;





FIG. 10

is a side view of the strip of

FIG. 9

;





FIG. 11

is a top view of a cap of shock and/or vibration absorbing material which separates the head and handle portions of

FIGS. 5 and 7

;





FIG. 12

is a side view of the cap of

FIG. 11

;





FIG. 13

is a side view of the cap of

FIG. 12

;





FIG. 14

is a front view of another embodiment of a game racquet which is formed in accordance with the invention;





FIG. 15

is a side view of the racquet of

FIG. 14

;





FIG. 16

is a front view of the head portion of the racquet of

FIG. 14

;





FIG. 17

is a side view of the head portion of

FIG. 16

;





FIG. 18

is a front view of the handle portion of the racquet of

FIG. 14

; and





FIG. 19

is a side view of the head portion of FIG.


18


.











DESCRIPTION OF SPECIFIC EMBODIMENTS




Referring to

FIGS. 1 and 2

, a tennis racquet


25


includes a head portion


26


and a handle portion


27


. The handle is aligned with a longitudinal centerline CL of the racquet. Although the invention will be explained with reference to a tennis racquet, it will be understood that the invention can be used with other game racquets such as racquetball racquets and squash racquets.




The head and handle portions can be formed from any conventional material for game racquets. For example, either or both of the head and handle portions could be made from thermoplastic or thermoset materials or a combination of thermoplastic and thermoset materials. The preferred material is a graphite and resin composite. The head and handle portions can be formed from the same or different materials.




The head portion includes a hoop


28


and a generally V-shaped throat portion


29


. The hoop includes a top portion


30


, side portions


31


and


32


, and a bottom or yoke portion


33


. The throat includes a pair of arms


34


and


35


which converge downwardly and inwardly from the sides of the hoop.




A string bed


36


is supported by the hoop


28


in the conventional manner. The string bed includes longitudinally extending main strings


37


and cross strings


38


.




The handle portion


27


includes a grip portion


40


which is wrapped with grip material and a throat portion which is formed from a pair of arms


41


and


42


which diverge outwardly and upwardly from the grip portion. Each arm includes an upper end


43


which is adjacent the juncture between the yoke


33


and the sides


31


and


32


of the hoop.




As will be explained in detail with respect to the embodiment illustrated in

FIG. 3

, material which absorbs shock and/or vibration is positioned between the head and handle portions and isolates the head and handle portions. Each of the head and handle portions is attached to the shock and/or vibration absorbing material, advantageously by adhesive or an adhesive agent, and the head and handle are thereby connected to each other.





FIGS. 3 and 4

illustrate another embodiment of a racquet


44


which is similar to the racquet


25


. The racquet


44


includes a head portion


45


and a handle portion


46


which extends along the centerline CL of the racquet. A bumper strip


47


can protect the top of the head portion if desired.




Referring to

FIGS. 5 and 6

, the head portion includes a hoop


48


and a V-shaped throat portion


49


. The throat portion includes a pair of arms


50


and


51


which extend downwardly from shoulders or undercuts


52


and


53


in the hoop


48


toward the longitudinal centerline CL. The lower ends of the arms are joined by a connecting portion


54


, and a tapered projection


55


extends downwardly from the connector


54


. Shoulders


56


extend laterally between the projecting


55


and the front and rear faces of the head portion.




Referring to

FIGS. 7 and 8

, the handle portion


46


includes a grip portion


62


and a throat portion which is formed from a pair of diverging arms


63


and


64


. Each arm includes an inside surface


65


and an angled upper end


66


which mates with one of the shoulders


52


or


53


. A socket


67


extends into the top of the grip portion between the arms


63


and


64


.





FIGS. 9 and 10

illustrate a panel or sheet


68


of material for absorbing shock and/or vibration which is positioned between the outer surfaces


57


of the throat portion and the inside surfaces


65


of the handle portion. The particular panel illustrated includes a flat end portion


69


which is provided with cutouts or recesses


70


and a pair of elongated parallel strips


71


which are joined by a crosspiece


72


. The strips are separated by recesses


73


and


74


. The recesses


70


,


73


, and


74


are intended primarily to reduce the weight of the panel


68


. However, the panel could be any shape and could be solid, i.e., without any openings or recesses. Alternatively, the shock and/or vibration absorbing material could be formed from a plurality of separate pieces.




The panel


68


can be formed from any material which provides shock absorbing and/or vibration dampening properties. Such materials include rubber, synthetic or butyl rubber, Kraton rubber, and urethane. One specific embodiment was made from soft chlorobutyl rubber which included filler and oils sufficient to provide a Shore A hardness of


33


.




The panel


68


preferably has a Shore A hardness within the range of 0 to 90, more preferably within the range of 20 to 70, and most preferably within the range of 30 to 60. Shore A hardness is measured in accordance with ASTM D-2240-00.





FIGS. 11-13

illustrate a cup


80


of shock absorbing material which is positioned between the projection


55


of the head portion and the socket


67


of the handle portion. The cup includes a sidewall.


81


which has the same dimensions as the socket


67


and a socket


82


which has the same dimensions as the projection


55


. Flanges


83


extend upwardly from two sides of the sidewall


81


, and flanges


84


extend laterally from the other sides of the sidewall


81


.




The cup


80


is attached to both the projection


55


and the socket


67


, preferably by adhesive or an adhesive agent which will not separate during normal use of the racquet. The preferred adhesive bonding agent is Loctite 496, which is a Cyanoasrylate Ester adhesive. The flanges


83


extend upwardly between the arms


50


and


51


of the head portion and the arms


63


and


64


of the handle portion. The flanges


84


extend between the top of the socket


67


in the handle portion and the shoulders


56


of the head portion. Similarly, a panel


68


is attached to the outer surface


57


of each of the throat arms


50


and


51


and to the inside surface


65


of each of the handle arms


63


and


64


. The strips are also preferably bonded by an adhesive, for example, Loctite 496.




The panels


68


and the cup


80


separate or isolate the head portion from the handle portion so that there is no direct contact between those parts. However, since each part is securely bonded to the panels


68


and the cup


80


, the parts are connected together by the panels and cup and will not separate during normal use of the racquet. The panels


68


and cup


80


significantly reduce the transmission of shock and vibration from the head portion to the handle portion.




If desired the projection


55


and socket


67


could be omitted. In that event the cap


80


can be replaced by a suitably shaped piece which prevents direct contact between the head and the handle.




A mechanical connection between the head portion and the handle portion can be provided by the racquet strings. Referring to

FIG. 5

, the head portion is provided with at least one string hole


85


which extends through the undercuts


52


and


53


of the throat arms


50


and


51


. A corresponding string hole


87


(

FIG. 8

) extends through the upper end of each of the handle arms


63


and


64


. The holes


85


and


87


are aligned when the head and handle portions are connected by the panels


66


and cup


80


. When the racquet is strung, one of the main strings


37


extends through the holes


85


and


89


on each side of the racquet and further secure the head and handle portions together. The strings extend through the middle recesses


70


in the panels


68


. Alternatively, the panels


68


could be shaped so that the strings do not pass through the panels.




The mechanical connection which is provided by the strings is located near the upper ends of the handle arms


63


and


64


. The lower ends of the handle arms are therefore free to move slightly relative to the lower ends of the throat arms


50


and


51


as the panels


68


and cup


80


are compressed by forces which are exerted on the racquet. Such relative movement assists in absorbing shock.




It is not necessary to have the racquet strings extend through the head and the handle. The head and handle could be connected solely by the adhesive bond to the vibration and/or shock absorbing material.





FIGS. 14-19

illustrate another embodiment of a racquet


90


which includes a head portion


91


and a handle portion


92


which extends along the centerline CL. the head portion


91


includes a hoop


93


which has a top portion


94


, side portions


95


and


96


, and a bottom or yoke portion


97


. A pair of short throat portions


98


and


99


extend downwardly from the yoke.




The side portion


95


includes a first outer edge


101


and a second recessed convex outer surface


102


which extends downwardly from about an undercut


103


at 4:00 o'clock to the end of the throat portion


98


. Similarly, the side portion


96


includes a first outer edge


104


and a recessed convex outer surface


105


which extends downwardly from an undercut


106


. Referring to

FIG. 17

, the recessed portions of the sides


95


and


96


taper inwardly at


107


so that the top and bottom edges


108


are offset toward the midplane MP from the top and bottom edges


110


and


111


of the remainder of the head.




The handle portion


92


includes a grip portion


114


and a throat formed by a pair of diverging arms


115


and


116


which extend away from the centerline CL. The arm


115


includes a lower portion


117


which has a concave inside surface


119


which mates with the convex outer surface


102


of the head. The arm


116


similarly includes a lower portion


120


and an upper portion


121


which has a concave inside surface


12


which mates with the convex surface


105


of the head.




A panel


124


of shock and/or vibration absorbing material is inserted between each of the arms


115


and


116


and the head and secured by a chemical or an adhesive bond. Each panel


124


is preferably similar to the panel


68


and is secured by Loctite 496 to both the head and handle portions. The panels isolate the head and handle portions.




A plurality of string holes


126


(

FIG. 17

) are provided in the recessed side portions


102


and


105


, and a plurality of string holes


127


(

FIG. 19

) are provided in the upper portions


118


and


120


of the arms of the handle portion. Strings which extend through the string holes


126


and


127


provide an additional mechanical attachment between the head and the handle.




If desired, the arms


115


and


116


of the handle portion can extend upwardly for a greater distance along the sides of the head portion. Also, the short throat portions


98


and


99


of the head can be omitted if desired. The head portion can be entirely hoop-shaped, and the arms of the handle portion can follow the contour of the hoop for any portion of the head which is desired. The handle portion can also extend along the centerline of the racquet up to the head portion so that the racquet does not have an open throat between the head and the handle.




While in the foregoing specification a detailed description of specific embodiments of the invention has been set forth for the purpose of illustration, it will be understood that many of the details hereingiven can be varied considerably by those skilled in the art without departing from the spirit and scope of the invention.



Claims
  • 1. A game racquet comprising:a head portion including a hoop and a throat portion outwardly extending from the hoop; a handle portion formed separately from the head portion; and shock and/or vibration absorbing material disposed between the hoop and the handle portion at at least one location, the hoop and the handle portion spaced apart by, and secured to, the absorbing material at the at least one location.
  • 2. The racquet of claim 1 in which the head portion and the handle portion are secured to the absorbing material by adhesive.
  • 3. The racquet of claim 1 in which the absorbing material separates the head portion and the handle portion and the head portion and the handle portion do not directly contact each other.
  • 4. The racquet of claim 1 in which the absorbing material has a Shore A hardness within the range of 0 to 90.
  • 5. The racquet of claim 4 in which the absorbing material is natural or synthetic rubber.
  • 6. The racquet of claim 4 in which the absorbing material is urethane.
  • 7. The racquet of claim 1 in which the absorbing material has a Shore A hardness within the range of 20 to 70.
  • 8. The racquet of claim 7 in which the absorbing material is natural or synthetic rubber.
  • 9. The racquet of claim 7 in which the absorbing material is urethane.
  • 10. The racquet of claim 1 in which the absorbing material has a Shore A hardness within the range of 30 to 60.
  • 11. The racquet of claim 10 in which the absorbing material is natural or synthetic rubber.
  • 12. The racquet of claim 10 in which the absorbing material is urethane.
  • 13. The racquet of claim 1 in which the head portion comprises a hoop having top, bottom, and opposite side portions and the handle portion includes a bottom grip portion and a pair of arms which extend upwardly from the grip portion and along the side portions of the hoop, said absorbing material being positioned between said arms and said side portions of the hoop.
  • 14. The game racquet of claim 1, wherein the at least one location comprises at least first and second spaced apart locations.
  • 15. The game racquet of claim 14, wherein the first and second spaced apart locations are positioned on the hoop at opposite sides of the throat portion.
  • 16. The racquet of claim 1, wherein the hoop and the handle portion each directly contact the absorbing material.
  • 17. The racquet of claim 1, wherein the absorbing material is formed of a material selected from the group consisting of natural rubber, synthetic rubber, butyl rubber, urethane, and combinations thereof.
  • 18. A game racquet comprising a head portion, a handle portion formed separately from the head portion, and shock and/or vibration absorbing material between the head portion and the handle portion, the head portion and the handle portion being secured to the absorbing material, the head portion supporting a plurality of strings, at least one of the strings extending through both the head portion and the handle portion to provide a mechanical connection between the head portion and the handle portion.
  • 19. The racquet of claim 18, wherein the hoop and the handle portion are secured to the absorbing material by adhesive.
  • 20. A game racquet comprising a head portion, a handle portion formed separately from the head portion, and shock and/or vibration absorbing material between the head portion and the handle portion, the head portion and the handle portion being secured to the absorbing material, the head portion including a hoop having top, bottom, and opposite side portions and a longitudinal centerline and a pair of throat portions which extend downwardly from the side portions toward the longitudinal centerline, the handle portion including a bottom grip portion and a pair of arms which extend upwardly from the grip portion away from the longitudinal centerline, said shock absorbing material being positioned between said throat portions and the arms.
  • 21. The racquet of claim 20 including a projection which extends downwardly from the throat portions of the head portion, and the handle portion has a socket between the arms, said downwardly extending projection extending into said socket and being separated from the handle portion by shock and/or absorbing material.
  • 22. The racquet of claim 21 in which the absorbing material which separates said projection and the handle portion is a cap which covers the projection.
  • 23. The racquet of claim 20 in which each of the side portions of the hoop is provided with at least one string hole and each of the arms of the handle portion is provided with at least one string hole and a string extending through at least one string hole of each side portion and each arm to provide a mechanical connection between the head portion and the handle portion.
  • 24. The racquet of claim 20 in which the absorbing material has a Shore A hardness within the range of 0 to 90.
  • 25. The racquet of claim 24 in which the absorbing material is natural or synthetic rubber.
  • 26. The racquet of claim 24 in which the absorbing material is urethane.
  • 27. The racquet of claim 20 in which the absorbing material has a Shore A hardness within the range of 20 to 70.
  • 28. The racquet of claim 27 in which the absorbing material is natural or synthetic rubber.
  • 29. The racquet of claim 27 in which the absorbing material is urethane.
  • 30. The racquet of claim 20 in which the absorbing material has a Shore A hardness within the range of 30 to 60.
  • 31. The racquet of claim 30 in which the absorbing material is natural or synthetic rubber.
  • 32. The racquet of claim 30 in which the absorbing material is urethane.
  • 33. A game racquet comprising a head portion, a handle portion formed separately from the head portion, and shock and/or vibration absorbing material between the head portion and the handle portion, the head portion and the handle portion being secured to the absorbing material, the head portion comprising a hoop having top, bottom, and opposite side portions, the handle portion including a bottom grip portion and a pair of arms which extend upwardly from the grip portion and along the side portions of the hoop, said absorbing material being positioned between said arms and said side portions of the hoop, the head portion supporting a plurality of strings, at least one of the strings extending through the head portion and one of the arms and at least done of the strings extending through the head portion and the other of the arms to provide a mechanical connection between the head portion and the handle portion.
  • 34. A game racquet comprising:a head portion including a hoop and a throat portion outwardly extending from the hoop; a handle portion formed separately from the head portion, the head and handle portions formed of substantially the same material; and shock and/or vibration absorbing material positioned between the head portion and the handle portion, the head portion and the handle portion being secured to the absorbing material, the absorbing material being positioned between the throat portion and the handle portion, and the absorbing material also being positioned between the hoop and the handle portion.
US Referenced Citations (8)
Number Name Date Kind
4139194 Fischer Feb 1979 A
4360202 Lo Nov 1982 A
4367871 Schiefer Jan 1983 A
4609198 Tarr Sep 1986 A
5071125 Shen Dec 1991 A
5178387 Kuebler Jan 1993 A
5236198 Haines et al. Aug 1993 A
5524884 Haines Jun 1996 A
Foreign Referenced Citations (3)
Number Date Country
3521621 Jan 1986 DE
2590802 Jun 1987 FR
2230458 Oct 1990 GB
Non-Patent Literature Citations (2)
Entry
“The ISIS System” from 1992 Catalog of Dunlop Slazenger Corporation.
“ISIS—Impact Shock Isolation System” from Dunlop 1994 Tennis Catalog.