Shockley, Gilbert R. (Richmond, VA)
Hafer, Richard F. (Richmond, VA)

05/262126

06/04/1974

06/12/1972

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Reynolds Metals Company (Richmond, VA)

473/544

A63B49/00; A63B49/02; A63B49/12; A63B49/10; A63B51/00

273/73R,73C,73D,73E,73F,73H,73K

3545756	TENNIS RACKET WITH STRING SUPPORTS OF VARIABLE RESILIENCY	December 1970	Nash
3690658	TENNIS RACKET	September 1972	Howe
3702701		November 1972	Vaughn et al.

Pinkham, Richard C.

Apley, Richard J.

What is claimed is

1. A racquet construction comprising, a frame having an ovaloid head portion terminating in a pair of closely spaced parallel extensions, said head portion being defined by a pair of spaced metal portions having inside surfaces which face generally toward each other, and a beam having a peripheral outline which corresponds substantially to the outline of said metal portions and being attached therebetween, said beam being made of a single body of one particular resilient elastomeric material which provides the sole support for adjoining stringing extending thereacross, said beam holding said metal portions in substantially parallel relation and when viewed at any cross section along its length is attached at its opposite end portions only against said inside surfaces while being unsupported between said end portions, said beam having different controlled radial thicknesses at different locations about its periphery, said different controlled radial thicknesses serving to control the resiliency of said beam and hence providing precision control of the resilient character of said stringing.

2. A racquet construction comprising, a frame having an ovaloid head portion terminating in a pair of closely spaced parallel extensions, said head portion being defined by a pair of spaced metal portions having inside surfaces which face generally toward each other, and a beam having a peripheral outline which corresponds substantially to the outline of said metal portions and being attached therebetween, said beam being made of a single body of one particular resilient elastomeric material which provides the sole support for adjoining stringing extending thereacross, said beam holding said metal portions in substantially parallel relation and when viewed at any cross section along its length is attached at its opposite end portions only against said inside surfaces while being unsupported between said end portions, each of said pair of spaced metal portions having a roughly U-shaped cross-sectional configuration defined by a bight and a pair of parallel legs extending from said bight, said metal portions being arranged with their outwardly extending legs extending toward each other and receiving said beam in nested relation therewithin and said inside surfaces include the inside surfaces of said bight and parallel legs.

3. A racquet construction comprising, a frame having an approximately ovaloid head portion terminating in a pair of closely spaced parallel extensions, said head portion being defined by a pair of spaced metal portions having inside surfaces which face generally toward each other, said metal portions being held together by a single body of one particular resilient elastomeric material which extends thereacross and defines a supporting beam for stringing provided as a part of said racquet and when viewed at any cross section along its length said beam is attached at its opposite end portions only against said inside surfaces while being unsupported between said end portions, and support means in said elastomeric material providing the sole support for said stringing, said support means comprising a plurality of substantially coplanar openings extending through said elastomeric material with said openings being adapted to receive individual strands of said stringing therethrough to enable attaching said stringing solely against said elastomeric material, said metal portions each having a channel-like configuration.

4. A racquet construction comprising, a frame having an approximately ovaloid head portion terminating in a pair of closely spaced parallel extensions, said head portion being defined by a pair of spaced metal portions having inside surfaces which face generally toward each other, said metal portions being held together by a single body of one particular resilient elastomeric material which extends thereacross and defines a supporting beam for stringing provided as a part of said racquet and when viewed at any cross section along its length said beam is attached at its opposite end portions only against said inside surfaces while being unsupported between said end portions, and support means in said elastomeric material providing the sole support for said stringing, said support means comprising a plurality of substantially coplanar openings extending through said elastomeric material with said openings being adapted to receive individual strands of said stringing therethrough to enable attaching said stringing solely against said elastomeric material, said metal portions each having a roughly U-shaped cross-sectional configuration defined by a bight and a pair of parallel arms with said parallel arms having transverse extensions which extend toward each other and have terminal ends arranged in spaced relation to define a space therebetween, said bight, arms, and extensions having inside surfaces which define said first-named inside surfaces and are in intimate contact with the elastomeric material and said elastomeric material extending through said space having a thickness which is substantially less than the thickness of said frame.

5. A racquet construction as set forth in claim 4 in which said elastomeric material has an inner and an outer surface, said outer surface being recessed inwardly of an outer surface of said metal portions by a distance which is substantially greater than the thickness of said stringing.

BACKGROUND OF THE INVENTION

There are numerous types of racquets in current use which are used in playing games, such as badminton, tennis, and the like, and these racquets generally use wood or metal to define frames for their head portions.

It is well known that racquets made of wood tend to warp even though they are stored in special clamping devices, and are comparatively difficult to string. Racquets made of metallic materials, such as steel and aluminum, reduce some of the problems of wooden racquets; however, they may create other problems.

It has been found that an improved racquet may be made by a unique combination of metal and a suitable elastomeric material and by employing not only the teachings of the racquet art but also concepts disclosed in U.S. Pat. No. 3,204,324 to Nilsen and U.S. Pat. No. 3,624,885 to Holliday and Barker.

SUMMARY

This invention provides an improved racquet construction, and method of making same, which may be produced with economy and overcomes certain deficiencies of wooden and metal racquets proposed heretofore.

In particular, the racquet construction comprises a frame having an ovaloid head portion terminating in a pair of closely spaced parallel extensions with the head portion of the frame being defined by a pair of spaced metal portions. A beam made of a resilient elastomeric material is formed between the metal portions and holds such metal portions in substantially parallel relation. The beam provides the sole support for adjoining stringing extending thereacross and has a resiliency which cooperates with the resiliency of individual strands comprising the stringing enabling the entire area within said head portion to be used as an effective striking surface.

Other details, uses, and advantages of this invention will become apparent as the following description of the exemplary embodiments thereof presented in the accompanying drawings proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings show present exemplary embodiments of this invention, in which

FIG. 1 illustrates one exemplary embodiment of a tennis racquet made in accordance with this invention;

FIG. 2 is an enlarged fragmentary view taken on the line of 2--2 of FIG. 1;

FIG. 3 is a view with parts in cross section and parts broken away taken essentially on the line 3--3 of FIG. 2;

FIG. 4 is an enlarged view similar to FIG. 3 particularly illustrating, in an exaggerated manner, the action of the resilient elastomeric material comprising the ovaloid head portion of the tennis racquet upon striking a tennis ball;

FIG. 5 is a fragmentary cross-sectional view taken essentially on the line 5--5 of FIG. 1;

FIG. 6 is a perspective view illustrating a bridge member comprising the tennis racquet of FIG. 1;

FIG. 7 is a schematic perspective view with parts in cross section and parts broken away illustrating an elongated channel-like metallic structure which is used to define the frame of a racquet construction being filled with a resilient elastomeric material;

FIG. 8 is a schematic presentation illustrating forming of the structure of FIG. 7 once filled with elastomeric material to define a racquet frame construction having an ovaloid head portion and a pair of closely spaced parallel extensions;

FIG. 9 is a cross-sectional view illustrating an elongated channel-like metallic structure which has been filled with an elastomeric material in a similar manner as the elongated structure illustrated in FIG. 7 and which is adapted to be formed to define another exemplary embodiment of the racquet construction of this invention;

FIG. 10 is a cross-sectional view taken essentially on the line 10--10 of FIG. 9; and

FIG. 11 is a view with parts in cross section and parts broken away of the racquet construction made utilizing the elongated structure of FIG. 9;

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Reference is now made to FIG. 1 of the drawings which illustrates one exemplary embodiment of a racquet construction or racquet of this invention which is designated generally by the reference numeral 20 and is particularly adapted for use in playing games such as badminton, tennis, squash, or the like. The racquet 20, which for simplicity and ease of presentation will be described hereinafter as a tennis racquet, comprises a frame 21 having an approximately oval-shaped or ovaloid head portion 22 terminating in a pair of closely spaced parallel extensions 23 which are held in position by suitable fasteners 24. A gripping handle 25 is fixed to the lower end portions of the extensions 23 and such handle is preferably provided with a suitable covering. The handle 25 may be fixed in position using any suitable means known in the art.

As seen in particular in FIGS. 3 and 4 of the drawings, the ovaloid head portion 22 is defined by a pair of spaced metal portions 26 and a beam 30 having a peripheral outline which corresponds substantially to the outline of the metal portions bonded in position. The beam 30 is made of a resilient elastomeric material and provides the sole support for adjoining stringing 31 extending thereacross and defined by cooperating strands 32 which extend horizontally and vertically, in the showing of FIG. 1.

The stringing 31 defines a substantially planar striking surface for the tennis racquet 20 and the strands 32 comprising such stringing have a normal resilient character or resiliency. As indicated above, the beam 30 is made of a resilient elastomeric material and such beam has a resiliency which is determined by the cross-sectional configuration and dimensions of such beam as well as the properties of the elastomeric material used to make the beam. Thus, the beam is made with an inherent controlled resiliency which cooperates with the resiliency of the strands 32 of the stringing 31 to assure that substantially the entire area confined within the head portion 22 is usable as a striking surface which is free of dead spots, such dead spots being common in wooden and metal racquets proposed heretofore.

The unique action provided by the beam 30 is illustrated in an exaggerated manner in FIG. 4 of the drawings wherein it is seen that once the stringing 31 of racquet 20 forcefully strikes an associated ball, the strands 32 are stretched slightly in the usual manner; however, the resilient beam 30 is also deflected from its normal solid line position essentially to a dotted line position as illustrated at 33 in FIG. 4.

Each of the metal portions 26 comprising the exemplary racquet 20 has a roughly U-shaped cross-sectional configuration, see particularly FIG. 4, defined by a bight 34 and pair of arms 35 extending from opposite ends of said bight in substantially parallel relation. The arms 35 of each portion 26 have transverse extensions 36 which extend toward each other and have terminal ends arranged in spaced relation to define a space 37 therebetween. The bight 34, arms 35, and extensions 36 of each metal portion 26 have inside surfaces in intimate contact with the elastomeric material defining the associated inner portion of the beam 30 and the thickness of the elastomeric material and, hence, of the beam 30, indicated at 40 in FIG. 3, is substantially less than the thickness 41 of the head portion 22 of the frame 21.

As seen in FIGS. 1-3, the beam 30 has an inner surface 42 facing toward the center of the ovaloid head portion 22 and an outer surface 43 which is recessed inwardly of the metal portions 26 by a distance indicated at 44, see FIG. 4, which is substantially greater than the thickness of the strands 32 defining stringing 31 and as illustrated at 45. This construction assures that the stringing is protected against impact which often occurs in the course of play by striking the racquet against the surface of the tennis court or may occur by inadvertent striking of objects during normal handling of a tennis racquet.

The racquet 20 also has a bridge member or bridge 46 (see FIGS. 1, 5, and 6) which is fixed to the frame 21 using any suitable means such as a pair of rivets 47, for example. The bridge 46 cooperates with the approximately ovaloid head portion 22 to complete the head portion of the racquet 20 as an oval. The bridge 46 may be made of any suitable metallic or nonmetallic material and in this example such bridge is made of a resilient elastomeric material and the detailed construction thereof is such that it provides resiliency in a similar manner as the beam 30 which is supported between metal portions 26.

The beam 30 provides the sole support for adjoining stringing 31 and in this example such beam has suitable means therein enabling the stringing 31 to be attached in position. In particular, the beam 30 has a plurality of openings each designated by the reference numeral 50 and each opening 50 is adapted to receive an associated strand 32 of the stringing 31 therethrough with the openings 50 being arranged substantially in a common plane.

The bridge 46 also has a plurality of openings 51 extending therethrough and the openings 51 are also in a common plane. The bridge 46 is installed in position by its rivets 47 so that the openings 50 and 51 are in substantially the same plane P, see FIG. 2, whereby the stringing 31 comprising the striking surface is essentially in one plane with the exception of the normal weave provided in such stringing and as illustrated at 52 in FIG. 3. However, it will be appreciated that each pair of immediately adjacent openings 50 and 51 may be arranged symmetrically on opposite sides of the plane P whereby an imaginary line through each of such pair of openings would be bisected by the plane P.

The racquet 20 may be made using any suitable technique known in the art including the teachings of the patents previously mentioned in the background portion of this application. For example, an empty channel-like elongated structure designated by the reference numeral 53 and made of a metallic material is moved through a filling station 54 where a suitable elastomeric material (which for simplicity is designated by the same reference numeral 30 as the beam 30) is suitably provided from a conventional source 58 to a filling head 55 and ejected from a nozzle 56 thereof into an open channel 57 in the elongated structure 53 so that a filled structure, designated by the numeral 60, is defined. The filled structure is suitably cured and/or cooled in accordance with standard practice depending upon the elastomeric material 30 employed and the cured and cooled structure is also designated by the reference numeral 60.

The frame 21 is formed using structure 60 and using any suitable technique or machine known in the art, such as a conventional tube bending machine. For simplicity, an apparatus and method for forming the structure 60 is illustrated schematically in FIG. 8 and comprises a fixture 61 having a suitable template 62 detachably fixed thereon. The template 62 has a configuration such that once the structure 60 is bent or formed therearound using conventional devices to apply bending forces as indicated by arrows 63, the structure 60 is bent around the template 62 so that even with normal springback of such structure after forming, the basic outline of the frame 21 with its ovaloid head portion 22 is defined.

The member 53 is preferably made by extrusion process and, as will be apparent from FIG. 7 of the drawings, the elongated metallic structure 53 is comprised of metal portions 26 joined together as a single unit by an integral member 64 extending therebetween and structure 53 may have suitable weakening lines 65 provided on opposite sides of portion 64. The weakening lines 65 are defined by projections in the extrusion die used to make structure 53 and lines 65 enable portion 64 to be readily grasped with a suitable device and severed from the completed structure 60 which is comprised of structure 53. However, it is to be understood that the structure 53 need not necessarily have weakening lines 65 therein and in this latter instance member 64 is cut or severed from structure 53 using any suitable means. The coplanar spaced openings 50 are then provided in the beam 30 whereupon the bridge 46, with openings 51 previously formed therein; and handle 25 are attached in position and the racquet strung with stringing 31 to define the completed racquet 20.

In the above description it is stated that the structure 60 is bent before severing the strip 64 therefrom; however, the strip 64 (regardless of whether it has weakening lines on opposite sides thereof is preferably severed prior to the bending step illustrated in FIG. 8. Similarly, openings 50 may be provided in the beam 30 prior to forming the structure 60 about template 62 and after severing of the strip portion 64. In this latter instance, it will be appreciated that the openings or holes 50 will extend through the beam 30 at the required angles of inclination and with the required spacing so that once the structure 60 is bent about template 62 to define the frame 21, the openings are arranged at the desired positions assuring the strands 32 are precisely positioned relative to each other and to define the stringing 31 essentially as illustrated in FIG. 1.

Another exemplary embodiment of the racquet construction or racquet of this invention is illustrated in FIG. 11 of the drawings. The racquet illustrated in FIG. 11 is similar to the racquet 20; therefore, such racquet will be designated by the reference numeral 20A and representative parts thereof which are similar to corresponding parts of the racquet 20 will be designated in the drawings by the same reference numeral as in the racquet 20 (whether or not such parts are described hereinafter) followed by the letter designation A and not described again in detail. Only those component parts of the racquet 20A or members used to make such component parts which are different from corresponding parts of the racquet 20 will be designated by a new reference numeral also followed by an associated letter designation and described in detail.

The racquet 20A is comprised of a frame 21A having an ovaloid head portion 22A and parallel extensions 23A. The head portion 22A is defined by a pair of channel-like metal portions 26A which are held together as a single unit in a bonded manner and spaced in substantially parallel relation by a beam 30A made of a resilient elastomeric material and the beam 30A has an ovaloid configuration which corresponds to the head portion 22A, see FIGS. 10 and 11.

The beam 30A has different thicknesses at various locations along its ovaloid path and as illustrated at 70A, 71A and 72A and each pair of immediately adjacent thicknesses is joined by a smooth transition section therebetween. Thus, the resiliency of the beam 30A at various points therealong is controlled not only by the resilient character thereof but also by its different thicknesses. The thicknesses of beam 30A at different locations are controlled to assure precision control of the resilient character of the stringing 31A at each location taking into account that at locations where the longest strands 32A are employed the beam 30A should be stiffest and where the shortest strands 32A are employed the beam 30A should have maximum flexibility.

The frame 21A is preferably made from an elongated structure 73A illustrated in FIG. 9 which is a roughly U-shaped structure having metal portions 26A interconnected by a strip 74A along weakening lines 75A. The structure 73A is filled with elastomeric material 30A in a similar manner as illustrated in FIG. 7 for structure 60, stripped of its elongated strip 74A along its weakening lines 75A and then bent or formed as illustrated in FIG. 8. To provide different thicknesses for the beam 30A comprising the ovaloid head portion 22A, an easily removed expendable insert 76A may be placed in the elongated U-shaped structure prior to filling with elastomeric material 30A, see FIG. 9, so that once the strip 74A is removed the insert 76A is also readily removed to define the beam 30A having the configuration illustrated in FIG. 11.

However, it will be appreciated that instead of forming the configuration of the beam 30A using an insert 76A other techniques may be employed such as initially defining the beam portion of a uniform thickness therealong and then suitably machining the desired configuration therein. However, irrespective of the manner in which different thicknesses are provided at its different locations, the beam 30A may have openings 50A formed therein either in its straight condition or after forming its central portion to define an ovaloid shape in order to allow the stringing 31A to be suitably supported solely by the beam 30A in a similar manner as the supporting of stringing 31 by beam 30 in the racquet 20.

The extensions 23 and 23A may be filled with elastomeric material or such extensions need not necessarily be filled with such material. In addition, in the extensions 23 and 23A the metal strip 64 and 74A respectively may be either left in position or suitably severed. Further, in order to achieve precise balance of the overall racquet, the severing may be achieved over any desired length of the racquet extension stopping at any desired position along such extension from either end thereof.

Any suitable metallic material may be used to define the metal portions of the racquet 20 and 20A; however, such racquets are preferably made using metallic materials containing aluminum or aluminous materials and the elongated channel-like structures 53 and 73A are preferably made by extrusion process with the weakened lines of separation defining each severable strip being defined in the associated extrusion die.

Any suitable elastomeric material which is capable of providing the performance desired herein when used in cooperation with the type stringing normally provided with a racquet such as a tennis racquet may be used to define beams 30 and 30A. Various plastic materials such as polymers have been used for this purpose and it will be appreciated that natural and synthetic rubber compounds may also be used.

While present exemplary embodiments of this invention, and methods of practicing the same, have been illustrated and described, it will be recognized that this invention may be otherwise variously embodied and practiced within the scope of the following claims.