US3810620A - Sports racket - Google Patents

Abstract

A frame for a sports racket comprising a pair of adhesively united metallic stampings and a handle for same. Each stamping is made from a metallic blank initially shaped similarly to the outline of the finished frame. Each blank is stamped to form a channel around its periphery. The channels in the respective blanks being so sized that when the blanks are assembled the outer legs of the channels overlap one another. The handle may be a molded rigid structural plastic foam.

Description

United States Patent 1191 Decker, III et al. I

[ SPORTS RACKET [76] Inventors: Charles R. Decker, III, 455 N. 5th

St., Warsaw, Ill-62319; Gregory K. Harris, Rural Rt. 2, Mooar, Keokuk, Iowa 52632 [22] Filed: Dec. 28, 1971 211 Appl. No.: 213,040

[52] US. C13. 273/73 H, 273/73 C, 273/73 J, v

273/D1G. 2, 273/D1G. 4, 273/D1G. 8, 273/DIG. 12 [51] Int. Cl A63b 49/12 [53] Field of Search... 173/73 R, 73 C, 73 D, 73 H, 173/73 .1

[56] References Cited UNITED STATES PATENTS 1,255,841 2/1918 Adams 273/73 H UX 1,587,919 6/1926 Morrison 1 273/73 H 1,750,644 3/1930 Norton 1 1 273/73 J 1,750,727 3/1930 N0rton..... 273/73 H 1.9l9,072 7/1933 Munday 273/73 H 3,083,968 4/1963 Takahashi 273/73 R ADHESIVE LAYER, e.g. aluminum 1451 May 14, 1974 4/1963 Lacoste 273/73 H FOREIGN PATENTS OR APPLICATIONS 14,247 10/1884 Great Britain 273/73 11 107,660 7/1917 Great Britain..... 252,133

7/1970 U.S.S.R 273/73 C PrimaryjExaminerRichard C. Pinkham Assistant Examiner-Richard J. Apley Attorney, Agent, or Firm-Austin P. Dodge; Robert A. Ostmann 1 ABSTRACT A frame for a sports racket comprising'a pair of adhesively united metallic stampings and a handle for same. Each stamping is made from a metallic blank initially shaped similarly to the outline of the finished frame. Each blank is stamped to form a channel around'its periphery. The channels in the respective blanks being so sized that when the blanks are assembled the outer legs of the channels overlap one an other. The handle may be a molded rigid structural plastic foam.

6 Claims, 10 Drawing Figures ADHESIVE LAY ER, e.g. aluminum filled epoxy PATENTEBIAY 14 m4 SNKU 10? 2 METAL BLANK, e.g. aluminum or steel FIG]- SHEET 2 BF 2 PATENTEBIAY 14 m4 6. A 3 ....1 l vs -v IFIG] FIGS FIG.5

RIGID STRUCTURAL PLASTIC FOAM, e.g. polypropylene, polystyrene, polyethylene or polyurethane 29 FIGS 1 SPORTS RACKET BACKGROUND OF THE INVENTION Metal framed tennis rackets have found widespread acceptance in recent years. Such rackets generally have included a metal frame having two handle or shank extensions made in one piece with a rim which encircles a major part of the head of the racket. The usual practice is to complete the encirclement of the racket head in the region of the throat by means of an insert which extends between the shank extensions of the frame. The lower ends of the centermost vertical strings and the ends of the lowermost horizontal strings are connected with this insert. The prior art show various forms of inserts and various schemes by which they may be secured to the frame. The Morrison US. Pat. No. 1,587,919 shows a racket in which two stamped channel form halves of the frame are secured together by deforming the metal. Thus the entire headencircling rim and the shank of each half is made of one piece of metal.

THE INVENTION This flat blank is then shaped by a stamping operation to provide a channel which extends from the base of the shank along its edge, the edge of the throat section and around the outer periphery of the head and back along the other edge ofthe throat section and the other edge of the shank to its base. The central opening will be enlarged somewhat during the formation of the channel, some of the metal being drawn into the channel. After stamping the central opening is finished to the final dimensions of the desired strung portion. The overwide rim in the blank serves not only to provide metal to be drawn into the channel, but also acts to keep the radial rims flat. The two stampings which make up a racket frame are of slightly different size so that the outermost legs of the channels may overlap and fit one another face to face over a substantial area. The abutting faces of the channel legs and of the radial rims are adhesively secured to one another. The planes ofthe adhesive joints are at right angles to one another. The resulting frame is a rigid subassembly and when provided with a handle and strings provides an excellent sports racket.

The handle may be wooden or metallic, but preferably takes the form of rigid structural plastic foam molded in place on the shank and the lower part of the racket head.

The preferred embodiment of the invention will be described having reference to the accompanying drawings in which:

- FIG. 1 is a plan view of the initial blank;

FIG. 2 is a plan view of completed frame comprising two stamped halves in face to face engagement;

FIG. 3 is a sectional view on the line 3-3 of FIG. 2;

' FIG. 4 is a sectional view on the line 4-4 of FIG. 2;

FIG. 5 is a plan view of a completed racket; FIG. 6 is a sectional view on the line 6-6 of FIG. 5;

FIG. 7 is a sectional view on the line 7-7 ofFIG. 5;

FIG. 8 is a sectional view onlirie 8-8 of FIG. 5; FIG. 9 is a sectional view on line 99 of FIG. 5; and

FIG. 10 is a sectional view on line 10l0 of FIG. 5.

The racket is fabricated from sheet metal such as aluminum or aluminum alloy. Work hardening aluminum alloys such as SAE No. 5154 and 5052 are suitable 'when the racket is to be used by the average player;

Metals other than aluminum, e.g. steel may also be used. A flat metal blank 21 see FIG. 1 is cut from the sheet (not shown). While cutting the blank, aelliptical opening 23 having its periphery at 22 is formed in the blank. The blank 21 is then stamped to. formthe member 24; see FIG. 2. This member 24 has a channel 25 which runs around the outer periphery ofthe head portion and along the edges of the throat 26 andshank 27. During stamping the peripheral edge 22 is drawn outward by the metal being drawn into the channel 25.

The opening 23 is initially somewhat undersized and the rim 29 is finished to its final dimensions after the stamping operation. During cutting of the blank a cutout 31 is formed at the throat26.

Two members 24 and 24'-- (see FIGS. 3 and 4) are connected face to face so that channels 25 and 25 en'- close the tubular space 28. The flat rims 29 and 29 which extend inward from the channels 25 and 25' are engaged face to face with their inner margins coinci- -dent as shown in FIG. 4. In the region ofthe shank 27 of the thus formed frame the two sets of channels 25 and 25' are connected by flat webs 32 and 32'. The legs of each channel are. of unequal lengths. The shorter leg 20 (20') is connected to the outer periphery of rim 29 (29'). The member 24' is slightly smaller than member 24 so that the longer legs 33 and 33 of the channels 25 and 25' respectively overlap one another and are in face to face engagement. The interface between legs 33, 33' and the one between rims 29, 29' are at right angles to one another. The strings of the racket will be coplanar with the rims 29, 29. An adhesive layer is provided in each of the interfaces between the legs 33 and 33', between the rims 29 and 29' and between the webs 32 and 32. This adhesive holds the two halves of the frame in assembled relation.

The frame comprising the adhesively interconnected may be united by the same adhesive as was used to unite the frame halves, or by rivets. This subassembly is then placed in a mold and a mass 36 of rigidstructural plastic foam formed around the handle, shank, throat and a part of the head of the frame. This foam may be polypropylene, polystyrene, polyethylene or polyurethane. Polypropylene is applicants preference.

The adhesive used to unite the metallic parts is an aluminum filled epoxy adhesive. A satisfactory adhesive of this type is available from the 3Ms Company and'is identified as 22l4 Hi Flex. This epoxy-basedaluminum-filled adhesive is a heat-curing structural ad'- hesive and is said to have increased flexibility. Other aligned holes in these rims, hold these rim faces tightly together. Thus'while use of two adhesive joints is preferred a single adhesive joint between may be used,

though the frames useful life may be impaired.

The rigid structural plastic foam may have any desired density. The presently preferred foam has a density, when made of polypropylene, of about 35 pounds per cubic foot. The extent to which the molded foam extends along the periphery of the head can be controlled and is selected to give the desired balance to the racket. Handles made of other materials may be used. For example wooden grips may be secured to the shank by rivets.

The frame shown in FIG. 2 may be formed with a longer shank which could be formed to provide a handle if desired. While this is practical, there is an increase in the waste left during the cutting of the initial blank. The illustrated head and shank to be provided with a handle is the preferred, because it is believed that a completed racket can be made from it more economically than the above described alternate form.

It will be obvious that rackets for use in various sports may be made utilizing the invention and no limitation to a racket useful in a particular game is intended. The drawings are intended only as a means of illustrating the invention. They are not intended to show any particular type of sports racket.

We claim: 1. A frame for a stringed sports racket comprising:

a. a pair of interengaging members; b. each member comprising l. a planar rim encircling an opening, shaped in accordance with any desired strung surface, said portion extending outward therefrom,

2. a continuous channel extending along the edges of said portion and around the outer periphery of said rim,

3. said channel having legs of unequal length which are perpendicular to the plane of said rim, the shorter leg interconnecting said outer periphery and the bottom of the channel,

c. the pair of interengaging members defining a frame having,

I. a double thickness web made up of said planar rims and said portions in face to face engagement, and

2. a hollow tubular part extending along the edges, I

of said portions and around the outer peripheries of said rims and made up of said channels whose longer legs overlap one another, the overlapping portions being in face to face engagement,

d. adhesive means uniting said interengaging mem- 7 said tubular extension.

6. The combination defined in claim 1 in which said adhesive means includes layers of adhesive between said overlapping portions of said longer legs and between said planar rims.

Claims (9)

1. A frame for a stringed sports racket comprising: a. a pair of interengaging members; b. each member comprising 1. a planar rim encircling an opening, shaped in accordance with any desired strung surface, said rim having an integral, coplanar throat and shank portion extending outward therefrom, 2. a continuous channel extending along the edges of said portion and around the outer periphery of said rim, 3. said channel having legs of unequal length which are perpendicular to the plane of said rim, the shorter leg interconnecting said outer periphery and the bottom of the channel, c. the pair of interengaging members defining a frame having, 1. a double thickness web made up of said planar rims and said portions in face to face engagement, and 2. a hollow tubular part extending along the edges of said portions and around the outer peripheries of said rims and made up of said channels whose longer legs overlap one another, the overlapping portions being in face to face engagement, d. adhesive means uniting said interengaging members.

2. a continuous channel extending along the edges of said portion and around the outer periphery of said rim,

2. a hollow tubular part extending along the edges of said portions and around the outer peripheries of said rims and made up of said channels whose longer legs overlap one another, the overlapping portions being in face to face engagement, d. adhesive means uniting said interengaging members.

2. The frame defined in claim 1; and a handle connected to said interengaged shank portions.

3. The racket defined in claim 2 in which said handle comprises molded rigid structural plastic foam.

3. said channel having legs of unequal length which are perpendicular to the plane of said rim, the shorter leg interconnecting said outer periphery and the bottom of the channel, c. the pair of interengaging members defining a frame having,

4. The racket defined in claim 2 in which said handle comprises a tubular extension connected to said shank portions and rigid structural plastic foam molded about said tubular extension.

5. The combination defined in claim 4 in which said foam also is molded about portions of said tubular part and said rims adjacent said throat and shank portions.

6. The combination defined in claim 1 in which said adhesive means includes layers of adhesive between said overlapping portions of said longer legs and between said planar rims.

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