CA1064983A - Method for making a tennis, badminton or similar racket net, net obtained by this method and racket comprising this net - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A method is disclosed for making a tennis, badminton or similar racket net. A board being provided with projecting nails, a thread or catgut is placed on the board along the sinuous contour of the cross-strings of a net and another thread or catgut is ?ced along the sinuous contour of the uprights of a net, using the nails as aids for defining said contours. Loops are formed at the connection between two successive cross-strings or uprights and the thus formed net is thereafter disengaged from the board.

Description

~L~649~3 This invention relates to a method for making a tennis, badminton or similar racket net, a net obtained using this method and a racket provided with this net.
Making racket strings is a relatively long and delicate operation which requires a specialist and is costly. Failure to observe the specifications of the string network may result in deformation of the racket frame.
The invention relates to a stringing method free of these drawbacks.
Whereas up to now the stringing of a racket was carried out using several lengths of catgut or similar material from each one of which, through threading in holes present in the frame, one or more cross-strings and one or more uprights were provided and whereas precautions must be taken in order lS to maintain under stress that part of the string network effected and als~ in order to prevent the deformation of the frame, according to the invention, on the contrary, the net or string network is produced without the mediation of khe racket frame, using a board or similar component on which are ~astened nails or catches in position~ such that by causing a len~th of catgut or khread to pa~s around said nails, said catgut or t~read takes up a position along a sinuous path in conormity with that of the cross-strings of a string network and by causing another length of catgut or thread to pass around them, said catguk or thread takes up a position along the sinuous contour corresponding to ~2--1~6D~983 the uprights of a string network.
The production o a net is thereore an operation which is distinct from the stringing of a racket. The latter is then carried GUt starting ~rom a net prepared in advance and simply comprises the stressing of a net inside a frame~
Furthermore, loops are formed at the connections between two successive cross-strings and between two successive uprights and ~hese Loops, after having been threaded into crossing passages present in a racket frame, contribute to the stressing of the string network.

The loops crossing the frame are maintained by a thread or peripheral cable to the frame which is threaded into said loops and subsequently stressed, maintain occurring by means of a strap or staple receiving the loop and bearing against the khread or cable.

The invention provides or the application of said straps or staples into that part of the racket frame which is opposite the handle in order to protect said frame from wear due to friction on the ground.
In a modification, the e~tremities of the cro~-strings or upright~ are assembled to each other by threading a string ex1;remity into the loop o~ an adjacent ~tring and the strings closest to the handle are extended along tails inside the latter, pulling on said tails contributing to the stressing of the ~tring network. Discs set into place before the assembly in that part of the frame opposite the handle provide then for protection from wear or deteriorations.

~6~g83 In one or the other of the embodiments, the periphery of the frame is undulated, so that maintaining under stress of each string is elastic as a result of the fact that the part of the cable or thread is interposed between two successive undulatlons like a bric3ge.
Uprights of the net extend along tails which are designed to penetrate inside a hollow racket handle and pulling on these tails contributes to the stressing of the string network.
The handle of the racket comprises,. on the one hand, means adapted to cooperate with the tails in order to provide for the stressing of the corresponding uprights and, on the other hand, for the stressing of the peripheral cable of the frame or the string tails adjacent to the handle.
In accordance with an aspect o~ the present invention there is provided a tennis, badminton, or similar racket comprising: a handle; a frame containing a plurality of holes, and having a convex shape in the areas between said holes; a net containing peripheral closed loops which extend through the holes in the frame: a cable located along the periphery of the frame, and in a threaded relation with said closed loops; and a means Eor applying tension to said cable so that the closed loops are pu].led out at the portionS of the c~ble over.lyiny the holes approaches the level defined by the apices of adjacent convex areas of the frame.
The following description given as an example, refers to the appended drawings, in which:
figure 1 is a plan view of a device for making a net during a p~oduction phase;

~06D~983 figure 2 is a view similar to that of figure 1 but for another phase;
figure 3 is a v.iew of a loop Eigure 4 is a schematic view of the arrangement of the loops of a net;
figure 5 is a view of part of a racket according to the invention partially broken away;
figure 6 is a view to a similar scale of a net:
figure 7 is a cross-sectional view along 7-7 of figure 5, to a larger scale - 4a -.ii~

~ \

~;491~3 figure 8 i5 a view of a string loop according to a particular embodiment;
figure 9 is a longitudinal sectional view along line 9-9 of figure 5 to a larger scale;
figure 10 is a longitudinal sectional view of a racket handle;
figure 11 is a view similar to that of figure 10 but along a perpendicular section;
: figure 12 is a view of a loop;
figure 13 is a sectional view of part of a racket for a modification;
figure 14 is a sectional view o part o a racket throùgh the m~an plane of the ~rame;
figure 15 is a view of a strap;
igure 16 is a sectional view along line 16-16 of figure 15 : figure 17 is a view of a strap, but perpendicularly to the view shown in figure 15 figure 18 is another view o a stxap;
figure lg is a view similar to that o figure 17, but ~or a modi~lcation;
figure 20 is a view similar to that o figure 13 but for another~embodiment;
igure 21 i~ a sectional view o part of a racket according to another embodimentr along the mean plane of the frame figure 22 is a view of a tightener;

~C~6q~ 83 figure 23 is an end view o~ said tightener;
figure 24 is a view similar to that of figure 22, but at 9o to the latter;
figure 25 is a perspective view of ~he tightener;
figure 26 is a view of a loop of central uprights;
figure 27 is a view to a larger scale of a part of figure 21 showing the hooking of the loops onto the tightener figure 28 is a sectional view along a plane perpendlcular to the mean plane of the ~rame at the latter's connection : with the handle;
figure 29 is a sectional view of a handle;
figure 30 is a sectional view along line 30-30 of figure 29 figure 31 is a sectional view along 31-31 of figure 29;
figure 32 is an end view o the handle through its back end;
: figure 33 is a perspective view of a stressing toolî
figure 34 is a view of part of a fram~ according to a particular embodiment.
On a board P, for ~xampla, made of wood (figure 1), are arr~nged a certain number of nails in places which will appear clearly from the following : a first strand of catgut or synthetic thread, for example, made of nylon, is fastened onto a nail CMl and the thread or cat~ut is stressed along a first upright Ml by causing it to pass around a nail C'Ml, and then a nail C'Ml 2 so as to form branches b'l and b'2 11D6~983 on either side of nail C'Ml 2' and then a nail C'M2 in order to form a second upright M2 parallel to upright Ml and distant from the latter by the usual ~istance between two neighbouring uprights of a net. The catgut or thread is then caused to pass around a nail CM2 and then a nail CM2 3 on either side of which it forms the branches of a v, respectively b2 and b3, and then a nail CM3 in order to form an upright M3, etc up to upright M5.
~Upright M5 is extended along a strand M'5 the length of which is somewhat less than that of a racket handle passing around a peg D5 6 the diameter o which is equal to the space between two uprights, and strand M'6 extends by upright M6, etc From peg D13 1~ leaves strand M'14 which extends by upright Ml~. Upright M15 is not extended by a strand so that it connects with upright M16 through two V-shaped branches b'l5 and b'l6. Upright M17 passes around nail C'M17 and then nail C'ML7 18 and beyond nail C'M18 the thread extends by uprighk M18 which passes around nail CMl~ whcre lt is fastened.
The cross-strings are similarly formed on the same board P:
from a nail CTL (figure 2) close to which is fa~tened the ex~remity of a thread or catgut comprising the cross-strings, the thread or catgut passes successively on nails C'Tl, C'Tl 2 C'T2 and con~inues through cross-string T2, the branches d' and d'2 on either side o nail C'Tl 2 being shaped as a V.
At each encounter of the thread or catgut of the cross-strings with the thread or catgut of the uprights, an overlapping occurs, so that, for example, cross-string Tl passes above 1~64983 the first upright which it encounters, which is upright M15 and then below the following upright which is uprighk M14, etc.~ as is usual in a string network. The connection between cross-string T3 and cross-string T4 is effected by passing around nails C'T3, C'T3 4, C'T4 with formation of branches d'3 and d'4 and so on.
Cross-string T20 connects with cross-string T21 by passing CT20~ CT20,21' CT21- The ~xtremity of the thread or catgut is fastened close to nail C'T21.
rrhe branches of the V's on either side of a same nail, p , b 1' b 2; b2, b3, etc., d'l, d'2; d2, d ; d' d' etc. are enclosed in a casing, or example, F'l 2 ~or the branches d'l, d'2, which thus ensure the formation oE a small loop BTl 2 (figure 3). A ca~ing or sleeve, F or F', i9 made of a retractable material; after the Eormation oE a loop and threading, an increase in temperature provides for contraction and thus for the integralization with the thread or catgut which it surrounds.
The various loops o~ the string network are arranged as shown in the diagram oE igure 4: Erom leEt to right and above, loop BTl 2 is ~ollowed by loop BMl, the notation meaning that it forms the end oE upright Ml; loop BMl is followed by loop BT3 4 which means that the loop belongs to the cross-strings T3 and T~ and then by loop BT5 6~ etc ~ter loop Brrl9 20~ is found loop BT21 and then loop BM3 4-The following loops have been designated B' in order to indicate that they are at the end of strands designed to extend ~6~3 on the inside o~ the handle. Thus, in succession, are found loop B~M5 6' loop B'~ ~, loop B'Mg 10' loop B Mll 12' looP B M13, 14 The following loop is a loop which connects directly to two uprights : it is loop BM15 16 which can be seen in the lower part. Then, from right to left, in succession, are p M17,18, loops BT20 21~ loops BTl~ 19' etc-~ BT
BT ~ BM , BT2 3~ BM16 17 up ~o loop BTl loops for the uprights, ~rom bottom to top, in succession 14,15 12,13~ Mlo,ll~ BM8 9 ~ BM6 7~ BM4 , BM
A cord~is then rolled around the string parts which would ac~uire obliqueness when put under stress as explained hereinafter, as a result o the connection between the adjacent cross-strings and adjacent uprights along converging part~.

The sides of the ~uares surrounded by such a cord have been marXed off on the drawing (figure S).
~7 The cord/is impregnated with a thermosetting resin, for example, an epoxy resin so that after curing, the non-d~formability of the rectangle, one side of which is surrounded by the cord, i9 thus ensured.
The net which has tails consisting of strands M' can be given separately to the racket manuEacturer or repairman.
It is ready to be assembled to a racXet frame.
Shown in fi~gure 6 to a smaller scale, is a net which is di~tinct from t~at described above only by the act that it comprises our central tails, Ql' Q2' Q3' Q4 two uprights and ending with small loops bl, b2, b3, b4, _g _ ~0~;49~3 as well as two lateral tails Q5, Q6' each also extending two uprights and ending with loops b5 and b6, which are longer than loops bl to b4. The length of loops b is determined by the length of the respective sleeves g which is greater for sleeves gl to g4 than for sleeves g5 to g6.
A net with peripheral loops B and with tails ending with loops b can also be obtained by molding of a fiber loaded resin.
A peripheral loop B is defined by a ring or disc 80 enclosing the two strands from which the loop originates (figure 7).
In the modification shown in figure 8, loop B is defined by a ligature 81 and is wrapped in a sleeve 82.
A net as shown in figure 4 or figure 6 may be assembled with a racket frame made of wood, metal or reinforced plastic p~ material. Frame 101 (igures S, 7~ ~ or 9) has a U-shaped cross-section with two branches 102 and 103 the base of which ga provides crossings 104 between the internal ace 99 of the base and the external face 105. The latter has undulations so that on either side of a hole in a crossing 104, the distance of the external face lOS to the i.n~ernal ace 99 fiL~st increases and then decreases until the next hole (figure 9~
~s far as stringing of the frame is concerned, loops B
are simply threaded into holes 104 at corresponding positions of the frame 101. Loops B project with respect to the external surface 105 and in the loops is threaded a thread or cable 110.

1~6~9~33 Said cable has its ends housed in a tubular handle 111 of khe racket (igures 10 and 11) and each one o them is formed by a loop, respectively 112 and 113, ligatured as shown in 114 (figure 12). Loops 112 and 113 are arranged around grooves 115 and 116 of a first spool 117 housed inside handle 111.
Spool 117 has a threading crossing 118 and the latter co-operates with a thread in a rod 119 which is coaxial with the handle and which ends with a head 120 comprising slit 121 providing for rotation with a screw-driver. Head 120 is housed in a cavity 122 located on a stopper 123 shaped as a disc whic~ seals the end o the handle. Said stopper extends through a tube 124 threaded on the outside and with which co-operates a threading 125 of a tubular nut 126 which extends through a tail 127. A second spool 128 whic~ is threaded inko loops B' is integral with tail 127.
Slab 129 of stopper 123 is knurled and, through rotation of said stopper, it is possible to increase or decrease the stress of strands M' extending the uprights. Through rotation o E head 120 using a coin, the stress on cable 110 i5 increased or decreased. When the stress o E said cable incr~ases, loops B are pulled towards the out~ide and this occurs as a result o ..he convexitie~ formed by the undulations of the e~ternal surace 105 of base 98 and on which bears cable 110 on either side o the loop. Each cord is thus astened to its ends on elastic bridges ormed by the cable portions between two successive convexities. The stress o E the string network can thus be set at will.

106~ 3 Cable 110 bears against the internal faces 131 and 132 of legs 133 and 134 for the connection of handle 111 to frame 101 .
Strands M' cross the cross-piece 135 through holes 136 present in the latter~
In the modification shown in figure 13, a loop 141 projects sufficiently with respect to the external surface 105 of the base 99 of frame 101 in order for sleeve 142 to be engaged therein~ Loop 143 projecting with respect to sleeve 142 is useful in turn for the engagement of an adjacent sleeve 144, etc Loop 145 of sleeve 146 which is the closest to cross-piec~
; ~3~
~'~,` 13~ is useful for stressing the cords as a whole.
Stressing of the strands inside the handle can also occur through twisting.
The strands inside the handle are made to follow a sinuous path so as to increase their length and thus their twisting possibilities.
In the embodiment shown in figure 14, the cro~sing~ 20L
are provided by cross-piece~ 202 interposed between two parallel 1anges 203 which are part o~ tho xame ~a~ket.
loop 205 is engaged between faces 206 and 207 which are provided by a slit 208 cut into the body 209 of a strap or staple 210 (figures 15 to 19) shaped as a pellet. Said strap has a milling 211 limiting branches 212 and 213 and having a convex bottom 214, the median milling plane 211 being perpendicular to the median plane of slit 208. The stressing 9~3 of a peripheral thread or cable 215 housed in the milling 211 applies said cable against the periphery of the cross-pieces 202 and furthermore ensures khe stressing of cords 216 which form loops 205. Cable 215 which bears on rounded parts of ~ 5 cross-pieces 202 thus ensures an elastic hooking of cords : 216 favoring the performance of -the racket during the game.
A coating can be provided on the surface of the staple defining the milling 211 as shown in figure 19.
In the embodiment shown in figures 15 to l9, the strap projects with respect to slab 217 of the frame and thus prevents the latter's contact with the ground when the racket is used to pick up a ball. Wear of the frame is thus avoided.
In the embodiment shown in 218 in figure 14, the strap is truncated on its body 209 so that face 219 resulting from the truncated character is recessed with respect to slab 217. Such a strap is used in those parts of the racket which are not opposite the handle and thus do not risk being worn out through contact with the ground.
In khe embodiment shown in figure 20, protection of the racket frame is obtained by threading a disc 222 towards the ~n~ o~ loop 205, the disc being, when the net is under stress, as shown on the left part of figures 13, between two cross-pieces 202l and 2022 of the frame, projecting with respect to slah 217 o~ the latter and thus ensuring its protective role from wear.
The disc is also shown in i~s position before stressing of the various tails, also in its position before threading .

~L0649~3 of the adjacent loop into the loop surrounded by the disc, ~inally in its position beEore its engagement at the end of the loop.
In the embodiment shown in ~igure 21, frame 230 of the racket comprises two flanges 231 made integral with each other ~hrough cross-pieces. cross-pieces 2321, 2322 and 2323, 2324, in the lateral parts of the frame opposite khe handle, are solid ana comprise a circular section. Cross-pieces 233 in the central part of the frame opposite the handle have a U-shaped section.
The~ also have a U-shaped section on the median lateral parts of the frame as shown in 234. On the opening parts of the frame 235, connecting with the handle, solid cross-pieces are found having a circular section 237 along an internal row and solid cross-pie¢es 23~ along an external row which also have a circular section but smaller than that of cross-pieces 237.
In this embod~ment, also, net 239 is autonomous, prepared in advance and provided with its straps which are also o~ two types, i.e., straps 210 designed to ~tress the net, when mounting it onto the rame through the action oE a banding thread or cable 2~1 and which, in addition, ?rotect the frame by avoiding the contact o slab 242 of the latter with the ground, and straps 218 which pla~ the same roles e7ccept that which has jU5t: been mentioned~
Net 239, in this e~odiment, con~ists of horizontal cross-strings (in the case in which the handle of the racket is placed vertically) 243, of oblique cross-strings 244 and of oblique uprights 245 and 246~ The configuration o E the cross-strings is thus of the zigzag type and the same is - true of the configuration of the uprights.
The e~tremities of the cord or similar component comprising the cross-strings are shown in 247 and 248 and the extremities of the cord comprising the uprights are shown in 249 and 250.
The stressing o~ the net occurs through a tightener 251 (~igures 22 to 25) which is advantageously made of a light alloy comprising, on either side of a central core 252 limited by two parallel faces 253 and 254, small tongues 255 and 256, defining with said core, housings 257 and 258 ending in convex bottoms 259 and 260.
On either side of body 261 are two ears 262 and 263 the mean parallel planes of which are perpendicular to the mean planes of the small tongues 255 and 256. ~he ears 262 and 263 provide with body 261 housings 264 and 26S the botkoms o~
which are shown in 266 and 267.
2û The uprights 2451 and 2~61 which are closest to axis 271 o khe racket and one 8 ido oE the latker ar~ connec~ed along a ioop 272 (~igure 26) limited by a tightening ring 273. Loop 272 is protected by a sleeve 274. Loop 272 is engaged in the housing 265 and its apex 27 5 (figure 27) comes into contact with bottom 267. Similarly, the loop which ends the symmetrical uprights with respect to axis 271, i.e., upri~hfts 2452 and 2462, is engaged in the housing 264 and its apex is in contact with bottom 266.

)649~3 `

The uprights which follow uprights 2451 and 2461, i.e., 2453 and 2463, form a loop 2763. The latter is threaded around a core 252 and its apex 277 comes into contact with slab 278 of said core. The symmetrical loop 279 is also engaged around said core and its apex 2~0 comes into contact with the opposite slab 281 of core 252.
The thread or cable 241 ends with a loop 282, which is engaged around core 252, beyond the first two loops and its apex 283 is in contact with slab 278. The other end of the thread or cable 241 forms a loop 2~4 the apex of which 285 is in contact with slab 281 of core 252.
The body 261 of tightener 251 has, opposite core 252, a platform 291 bordered by rims 292 and 293~ It is with this platorm that apices 294 and 295 of loops 296 and 297 are in contact ~orming the extremity of slings 298 and 299 (fig. 28) housed inside the handle 236.
The other extremities of the slings also form loops 301 and 302 and said loops are engaged in grooves 303 and 304 (figure 29) having a semi-~ircular configuration, present in a head 305 (~igures 30 to 32) having a generally xectarlgular shape and housed in the compartment 306 inside the handle with a corxe~ponding cro~s-s~ction.
Head 305 is integral with an externally threaded tube 307 which co-operates with the internal threading 30~ o~ a tube 309 which ends at its opposite extr~mity with a base 310 sealing body 311 of the racket handle. Base 310 comprises a 6~9~33 hexagon or similar shape 312 for its putting into rotation, for example, through the projecting part 313, having a conjuyated shape, of an actuating circular tool 314 (igure 33).
A disc 315 is interposed between the base 310 and the body 311 of the racket handle.
When base 310 is turned in a suitable direction, the tube 307 is pulled towards said base, head 305 opposing the rotation of said tube. The slings 298 and 299 exert their action on the tightener 251 and simultaneously, the peripheral cable lo 241 and the central uprights 245, 246 of the racket net are placed under stress. ~t the moment the stress is exerted, small tongues 255 and 256 of the tightener oppose the disengagement of the loops in which core 252 is engaged.
As cable 241, which bears against the frame cross-pieces, is placed under stress, the bridges formed by said cables between the two adjacent cross-pieces are stretched, which resalts in the stressing o the cords overlapping the strap on which the action o said bridye is exerted. As a result, khere occurs, in conjugation with the action e~erted directly onto the central uprights, a uniorm stressin~ o al}
com~onent cords of the net and at a value whiah i~ suitable for the ball game.
In the embodlment shown in figure g~, frame 330 has a window 331 through which a xeference mark 332 is visible carried by tightener 251. At the moment of stressing, said reference mark moves in ront oE the graduations of a scale ~ ~06~9a~3 333. It is thus possible to be informed at any moment as to the degree of stress of the string network and to make adjustments in accordance with the wishes of the player.

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Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A tennis, badminton, or similar racket comprising:
a. a handle;
b. a frame containing a plurality of holes, and having a convex shape in the areas between said holes;
c. a net containing peripheral closed loops which extend through the holes in the frame;
d. a cable located along the periphery of the frame, and in a threaded relation with said closed loops;
and e. a means for applying tension to said cable so that the closed loops are pulled out at the portions of the cable overlying the holes approaches the level defined by the apices of adjacent convex areas of the frame.

2. The racket according to claim 1, in which a means for applying tension directly to at least some of the closed loops is provided.

3. The racket according to claim 1, in which a groove is provided around the periphery of the frame for receiving the cable.

4. The racket according to claim 1, in which the means for applying tension in the handle is located at the end of the handle opposite the frame.

5. The racket according to claim 1, in which the frame is constituted by two symmetrical flanges, and where crosspieces between said flanges define the convex shapes in the areas between the holes in the frame.

6. The racket according to claim 1, in which the net comprises:

a. cross-strings formed by the sinuous threading of a thread-like material;
b. upright strings formed by the sinuous threading of a thread-like material, and interwoven with the cross-strings;
c. tie means connecting each successive pair of uprights and cross-strings, respectively, thereby defining closed loops along the periphery of the net, and d. at least one cord interwoven with the uprights and cross-strings near the closed loops in order to maintain a parallel relationship between each pair of successive uprights and each pair of cross-strings, respectively.

7. The racket according to claim 6, in which the tie means is a sleeve.

8. The racket according to claim 6, in which the tie means is a ligature.

9. The racket according to claim 6, in which at least one of the closed loops defined by the uprights and the associated tie means is larger than the closed loops defined by the cross-strings and their associated tie means.

10. A racket according to claim 1, wherein the tightening action of the cable on the closed loops is exerted through straps overlapping the cable and overlapped by the loops.