US 5,110,125 AGrant
Sport Racket
Issue Date:1992-05-05
•7 Claims
•2 Drawing Sheets
Abstract
A sport racket is provided wherein the thickness (e) of the cross section of the racket frame at the head and shafts is smaller than the thickness of the frame at the handle. This cross section has a constant perimeter, and has a maximum thickness (e) at the median side areas of the head of the racket.
Metadata
Assignee
- Skis Rossignol S. A.
Inventor
- Annie Blanc
Application Information
Application Number:US 6584403
Filing Date:1991-02-20
Priority Date:1988-04-26
Art Unit:334
Classifications
IPC:
A63B 4902
Field of Search:
27373 R;73 C;73 D;73 F;73 G
Patent Drawings (2 sheets)
Description
Brief Description of the Drawings
The invention shall be clearly understood and its advantages and additional characteristics disclosed in the following description of a non-restrictive example of an embodiment, with reference to the attached schematic drawing, wherein:
FIG. 1 is a perspective view of the racket;
FIG. 2 is a flat view of the racket, not including the strings;
FIG. 3 is a side view according to F in FIG. 2;
FIGS. 4, 5, 6 and 7, are cross sections of the frame seen respectively along 4--4, 5--5, 6--6, and 7--7 in FIG. 2, and
FIG. 8 is a detailed view with a cross section of a portion of the head of the racket, at the level of a cross string.
Detailed Description of the Invention
With reference to FIG. 1, the tennis racket is composed of a handle or grip 1 which is extended by two shafts 2, 3 that hold head 4, the lower part of which forms bridge 5. The head 4 itself holds strings 6, composed of main strings and cross strings, which form the striking surface.
With reference now to FIGS. 2 to 7, thickness e of the frame of the racket, more specifically that of shafts 2, 3 of head 4, is smaller than thickness E of handle 1. Moreover, cross section S (see FIGS. 4-7) of the frame varies along shafts 2, 3 and head 4, with the perimeter of the cross section S still remaining constant along the shafts and the head. Thickness e of the cross section S is at its maximum in the median area (respectively 7 and 8) of the two side parts of head 4. The cross section S in this area can be seen in FIG. 4. In the same median area 7, 8, width L of variable cross section S is at its minimum value, while ratio e/L is at its maximum value and is equal to 2.2 in this example, so that cross section S has a substantially elongated aspect in the direction of thickness e.
On the contrary, at shafts 2, 3, thickness e of cross section S is at its minimum value, while its width L is at its maximum value, as shown in FIG. 7: in these areas, cross section S has a substantially solid aspect, with ratio e/L being at its minimum value, equal to 1.53 in this example.
The cross section of the frame at crown 9 of the head is shown in FIG. 6. In this area, the aforementioned e/L value substantially constitutes the average of the value at the median side areas (FIG. 4) and at the shafts (FIG. 7): in this specific example, the ratio e/L at the crown of the frame is equal to 1.82.
Of course, the variations in cross section are progressive all along the frame. For example, FIG. 5 shows the cross section of the frame in areas 10 and 11, which make the transition between median side areas 7, 8 and crown area 9 on the one hand, and between the areas 7, 8 and shafts 2, 3 on the other hand.
Finally, in order to produce an effective arrangement of the strings of the frame, it was found advantageous not to provide the frame with an outside groove for the passage of the strings. The outside groove is replaced with a band 12 mounted around head 4, containing elongated sockets 13 to accommodate strings 14, as shown in FIG. 8.
Obviously, the invention is not limited to the example embodiment described above, and, on the contrary, can be executed in multiple equivalent forms. Of course, it applies to rackets for ball sports in the same family as tennis rackets, such as squash or badminton rackets. Generally speaking, the aforementioned ratio e/L is between 2 and 2.5 at the median side areas 7, 8, it is between 1.3 and 1.6 at shafts 2, 3, and is between 1.6 and 2 at crown 9.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and therefore such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation.
Claims
What is claimed is:
1. A sport racket made of composite material having as a base a fibrous reinforcement and a matrix composed of organic material, said racket comprising: a frame having two shafts connected to a head which holds strings to form a striking surface; wherein the cross-section of the frame varies along the shafts and head such that said cross-section has a maximum width (L.sub.1) and a minimum thickness (e.sub.1) along said shafts, a minimum width (L.sub.2) and a maximum thickness (e.sub.2) along median portions, and a width (L.sub.3) and a thickness (e.sub.3) at a crown portion of said head which are intermediate the cross-sections of said shafts and said median portions, the thickness (e.sub.1) of said shafts being smaller than the thickness of a handle of the racket; and wherein the cross-section maintains a constant perimeter along the shafts and the head.
2. A racket according to claim 1 wherein the frame has no outside groove for the passage of strings.
3. A racket according to claim 1 wherein the thickness (e.sub.1) of the frame is at its minimum in the areas of the shafts.
4. A racket according to claim 3 wherein at the crown of the frame, the ratio e.sub.3 /L.sub.3 between the thickness and the width of the cross section is substantially equal to the average of the ration taken at the median side areas of the head and at the shafts.
5. A racket according to claim 4 wherein the ratio e.sub.2 /L.sub.2 is between 2 and 2.5 at the median side areas, the ratio E.sub.1 /L.sub.1 is between 1.3 and 1.6 at the shafts, and the ratio e.sub.3 /L.sub.3 is between 1.6 and 2 at the crown.
6. A sport racket made of a composite material including a fibrous reinforcement and a resinous matrix, said racket comprising: an elongated handle portion having a pair of shafts divergently extending from an end thereof and a head extending from said shafts which holds strings to form a striking surface, said shafts and head comprising a frame; said head defining a first transition portion (11) closest to said shafts, a median portion (7, 8) adjacent said first transition portion, a second transition portion (10) adjacent said median portion (8) and a crown portion (9) farthest from said shafts, said frame having a varying cross-section from said shafts to said crown whereby the cross-section at said shafts has a maximum width (L.sub.1) and a minimum thickness (e.sub.1), the cross-section at said median portion has a minimum width (L.sub.2) and a maximum thickness (e.sub.2), the cross-section at said crown has a width (L.sub.3)and a thickness (e.sub.3) which are intermediate the cross-sections of said shaft and said median portion, and the cross-section of said transition portions varies gradually between said shafts and said median portion and between said median portion and said crown; each of said thicknesses of said frame being smaller than the thickness of said handle.
7. A racket according to claim 6 wherein the ratio e.sub.2 /L.sub.2 is between 2 and 2.5 at the median portions the ratio e.sub.1 /L.sub.1 is between 1.3 and 1.6 at the shafts, and the e.sub.3 /L.sub.3 is between 1.6 and 2 at the crown.