EP0644790A1

EP0644790A1 - Bowls and process for their production.

Info

Publication number: EP0644790A1
Application number: EP93913108A
Authority: EP
Inventors: Vartan Berberian
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-06-10
Filing date: 1993-06-10
Publication date: 1995-03-29
Anticipated expiration: 2013-06-10
Also published as: ATE131736T1; DE69301093D1; US5556342A; FR2692159B1; FR2692159A1; CA2137569A1; WO1993025284A1; DE69301093T2; EP0644790B1; DK0644790T3; ES2081218T3

Abstract

PCT No. PCT/FR93/00552 Sec. 371 Date Feb. 21, 1995 Sec. 102(e) Date Feb. 21, 1995 PCT Filed Jun. 10, 1993 PCT Pub. No. WO93/25284 PCT Pub. Date Dec. 23, 1993Bowl for games such as petanque, including an outer surface (2) composed of a base surface (4) with prominent patterns (3, 103), regularly distributed on at least 90% of the total base surface (4). The total surface occupied by said patterns (3, 103) on the base surface (4) represents at least 30% of the latter (4). The patterns (3, 103) are bordered by substantially cylindrical surfaces (4), with their generatrices (6) being almost parallel, within a small angle, known as the offset angle (D1).

Description

BALL FOR BALL GAMES AND METHODS OF OBTAINING SUCH A BALL

The subject of the present invention is a ball for ball games, usable for ball games, in which in particular a ball is rolled on the ground, for example the Provençal ball, the Lyonnaise ball, the Italian ball and, more particularly, bowls ; it also relates to methods of obtaining such a ball.

It is known that, in the aforementioned ball games, the player searches for a ball which has as little rebound as possible when it strikes another ball and which, also, is little deviated when it touches the ground and when it follow as best as he can; he also wants it not to be deflected by roughness from the ground when it rolls on it, or braked when it rolls on the ground; the player also wishes that the ball can be well held in hand and be pleasant to the touch.

In the case of pétanque, the "pointer" who seeks to place his ball as close as possible to the "jack", wishes to control the trajectory of his ball and wishes that his ball is not deflected during impact with the ground, or by a roughness of the ground, when it rolls on the latter. The "shooter" wants his ball to move back as little as possible under the effect of the shock, when his ball hits the ball of an opponent, so as to do what is called "a square on the spot".

In the current practice of petanque, the "pointer" and the "shooter" use different hollow metal balls: the "pointer" uses relatively small diameter and hard balls, often provided on their surface with families of circular, parallel grooves or orthogonal, which make it possible to brake the ball when it rolls on the ground; the "shooter" generally employs balls of lower hardness, called "soft", and of larger diameter so as to reduce the phenomenon of rebound during the impact of his ball with another ball; however, in practice, it is difficult to obtain balls having a sufficiently low rebound, and giving satisfaction, because such balls have too low a hardness and are, after a short use, marked and deformed, which leads to their confer random behavior. It is therefore particularly interesting to seek to produce balls having a low rebound which can also be used by the "shooter" as well as by the "pointer", to the nearest diameter. The jack is generally made up of a solid ball made of boxwood or other or of a plastic material of the same density whose surface is smooth. During an impact with a ball, the "pig" tends to rebound and roll on the ground randomly because it is not braked.

To limit the rebound phenomenon of a hollow metallic pétanque ball, it has been proposed in FR-A-2 638 375 to machine, on the internal surface of the two hemispherical shells forming the ball after assembly, streaks constituting either a network of circles parallel to each other, that is to say two networks of circles orthogonal to the crossing points, in a similar manner to the parallels and to the terrestrial meridians. However, this embodiment does not limit the rebound sufficiently homogeneously. Indeed, the thickness of the wall being reduced at the level of the ridges, the rebound is limited when the impact takes place at this level. However, there remain areas where the thickness of the ball is not modified and there is no obstacle to the propagation of the shock wave in the material constituting the ball; the rebound therefore remains significant and the behavior of the ball at impact remains uncertain. Furthermore, it is known to have streaks on the outer surface of the ball to brake it and increase its grip on the ground. However, streaks arranged on the ball may allow the penetration of an asperity of the ground in said streak and, therefore, an unexpected deviation of the ball. In French patent applications 90 13030 filed on

October 22, 1990 and 90 16538 filed on December 31, 1990, the applicant proposed a ball, in particular a hollow metal ball, possibly having on its internal face hollow patterns and on its external face of hollow and / or raised patterns regularly distributed. This ball makes it possible to satisfactorily resolve the problem of rebound; it can be used by both the "pointer" and the "shooter" and it is pleasant to hold in hand. In addition, the rail effect due to the streaks disappears completely, thus avoiding any unpredictable deviation. However, the manufacture of this type of ball has certain drawbacks. Obtaining half-spheres from flanks preformed, possibly from plots, having recessed or raised patterns on their internal or external face is difficult to produce and, consequently, the manufacturing cost is high. In addition, the thinner areas of the ball are relatively weakened by the operation.

The present invention relates to a ball insensitive to the rail effect, the behavior of which is satisfactory with regard to the problem of rebound, which can be used, in the game of pétanque, both by the "pointer" and the "shooter", which is not fragile, taking into account the repeated shocks which it is brought to receive, and which is obtained by a manufacturing process at competitive cost price.

According to the present invention, a ball, for bowling games, in particular for pétanque, comprising on its external face, patterns in relief, relative to a base surface, regularly distributed over at least 90% of the whole of said surface. base, the surface occupied by all of the relief patterns on the base surface representing at least 30% of said base surface is characterized in that said relief patterns are bordered by substantially cylindrical surfaces whose generatrices are parallel, to a small angle, called the draft angle.

Thus, also according to the present invention, such a ball is produced by forging, stamping or foundry, hollow or relief patterns on the external and / or internal faces of preformed hemispheres, in directions substantially parallel, at the angles of skin close, to facilitate the release of the tools, therefore of the part.

Indeed, to facilitate the release of the parts, the surfaces bordering said patterns are practically cylindrical, in fact slightly conical due to the draft angle. According to a first embodiment of the invention, each relief pattern on the external face of the ball occupies from 0.01% to 0.5% of the base surface, the surface of all the relief patterns representing at least 70% of said external face, all the patterns comprising a culminating zone tangent internally to the same spherical envelope or forming part of said envelope, the radius of curvature of said culminating zone being between 1 mm and the diameter of said spherical envelope, and the culminating zones being situated above the base surface at a height of between 1% and 5% of the diameter of said spherical envelope.

The minimum distance, measured on the base surface, between two relief patterns is advantageously between 0% and 5% of the diameter of the spherical envelope. Thus, the base surfaces of two adjacent patterns can have a common line, be tangent or be spaced.

It is also possible to provide, to allow identification of the ball, to have, on the culminating zone of at least part of the relief patterns, small cavities in the form of a concave spherical cap; these cavities have, for example, a maximum diameter of 2 mm and a depth of 0.5 to 2 mm for a pattern whose culminating zone is a spherical cap having a diameter of 6 mm; these small cavities can be filled with colored resin.

According to a second embodiment of the invention, all the relief patterns are connected to each other, revealing recessed patterns separated from each other, at the base surface, said recessed patterns each occupying 0.01% to 0.5% of the base surface of the ball, the surface of all the hollow patterns representing from 10 to 70% of said external face.

It can advantageously be provided that the hollow patterns of the external surface of a ball according to the invention have a depth of between 0.5 and 4% of the external diameter of the ball. To differentiate the ball, it can be colored by copper plating, brass plating, zinc plating, chrome plating or the like; a subsequent polishing, carried out in manufacturing or due to the wear of the ball, of the external face of the ball leaves the color due to this treatment only in the hollows of the external face, the raw material of the ball n ' appearing, after polishing, only on the relief patterns. This gives a very aesthetic appearance to the ball, and of course, it is possible to distribute areas of different color on said external face, each hemisphere being able in particular to be of different color. It is also possible to color the hollows by depositing a colored plastic material, for example an epoxy resin, which does not sit flush with the external face. It has been found that, thanks to the presence of recessed or raised patterns arranged on the external surface of the ball, the handling of said ball is easier and more comfortable. In addition, the ball, when it rolls on the ground, is braked by the recessed or external relief patterns which cooperate with the roughness of the ground to slow down and stop the ball and thus promote the adhesion to the ground of said ball. In addition, the ball more easily keeps the desired direction because, unlike the continuous circular grooves of the prior art, the recessed or raised patterns do not define continuous lines, promoting the rail effect. In addition, during a rebound, the ball according to the invention is practically never abnormally deflected due to the regular distribution of the hollow or relief patterns and their small individual surface.

The ball may be full. This is more particularly the case of the "pig". In this case, it is preferably obtained by molding a plastic material having a density close to that of wood.

According to a preferred embodiment of the invention, the ball is hollow and has on its internal face hollow or raised patterns bordered by substantially cylindrical surfaces whose generatrices are parallel.

Preferably, each raised or hollow pattern of the internal face is projected, according to said parallel generatrices, at least partially but preferably integrally, on the area occupied on the external face respectively by a hollow or raised pattern. According to the preferred embodiment in which each pattern of the internal face is projected, along the parallel generatrices, entirely on the area occupied on the external surface by a pattern, the rebound is greatly limited and it is practically homogeneous. Indeed, in this case, the thickness of the wall is not very variable and it somehow undulates around an average spherical surface. Consequently, at the time of the impact of the ball on another ball or on the ground, there is, in addition to the radial deformation, a deformation in a plane tangent to the average surface which makes it possible to limit the elastic rebound. The thickness of the wall varies little, the limited elastic rebound varies little from one point of impact on the ball to another. Rebound limited elastic is therefore practically constant from one point to another of the ball.

The hollow or raised patterns represent, on the external or internal face of the ball, a geometric figure which preferably has symmetry with respect to at least one axis and which forms, for example, a square, a rectangle, a rhombus, an equilateral triangle, a hexagon, a circle, an ellipse, a cross or a star. The figures can however be non-symmetrical figures such as a non-equilateral triangle, a semicircle and, possibly, a symbol like those used on playing cards (clover, heart, spades, square).

The base surface is. preferably spherical, advantageously concentric with the spherical envelope.

According to another embodiment, the patterns on the external face of the ball have a trapezoidal shape and are distributed over the base surface along meridians and parallels of the ball, leaving spaces of constant width between each trapezoidal pattern. .

All the relief or hollow patterns preferably have the same shape and the same dimension on the same surface on the same ball, that is to say that the sections of the cylindrical surfaces by the external face of the ball are substantially equal. However, provision can be made for certain relief patterns to have a different shape and / or more particularly a dimension so as to allow the ball to be identified, and by grouping patterns, for example.

According to a preferred embodiment of the invention, the cylindrical surface which defines the patterns on the internal and / or external face of the ball has a cross section which decreases from the pole of the hemispheres constituting the ball up to their equatorial zone . In particular, in order to obtain patterns of the same surface on the external face of the ball, said patterns are bordered by substantially cylindrical surfaces whose outline is an ellipse, said ellipse comprising a major axis equal to the diameter of the circle at the top of the hemisphere and a small axis whose projection, along a generatrix of the cylindrical surface on the external face, is equal to the diameter of said circle at the top of the hemisphere. There are preferably the same number of patterns on the external face as on the internal face.

According to the invention, the external face, and possibly the internal face of the ball, has an area devoid of patterns, this area possibly representing up to 10% of the base surface. This zone is, most often, an annular zone situated between two planes parallel to the equatorial plane; this equatorial annular zone generally corresponds, when the ball is hollow, to the welding zone of the two hemispherical shells assembled to form the ball. This area can be used to display on the outside of the ball characteristic marks or designs such as logos, initials, numbers, weight, series or player's name.

Petanque balls are generally, in known manner, hollow metal balls having a weight of between 700 g and 800 g approximately, a diameter of between 70 mm and 80 mm, and a thickness of 5 mm to 7 mm. The hollow patterns of a ball according to the invention then generally have a depth of between 0.5 and 2 mm approximately. Petanque balls are most often made of carbon steel or stainless steel; balls intended for games on smooth or carefully prepared grounds can also be made of brass or aluminum bronze.

The presence of relief or hollow patterns on the outer face of the ball allows the ball to cling to the ground and allows the "pointer" to control the trajectory of his ball, especially when it has given effect to his ball.

It will also be noted that the relief patterns constitute, quite naturally, indicators of wear of the ball. In addition, the presence of hollows and bumps prevents the propagation of the shock wave on impact of the ball, which increases the resistance of the ball, and, in particular, limits the brittleness of the welds of the two half spheres and even allows the application of cold welds, simpler to use, such as special glues of the type sold under the ARALDITE brand.

The interior of the ball can in particular comprise a single hollow or hump, a distribution in honeycombs of hollows or bumps, or a partitioning in hollow or in relief. In order to reduce, if necessary, the unbalance of the ball, the poles and the equatorial zone may include bosses on the internal face of the hemispheres.

When the two hemispheres are assembled by welding, a bevel chamfer, provided at the equator, facilitates this operation. Preferably, to center the two hemispheres, an annular central groove is formed in the thickness of the wall of the two hemispheres located in the equatorial plane, so as to accommodate a single ring connecting the two hemispheres. This ring can have any section, square, circular, rectangular. The annular groove can be continuous, but also discontinuous and materialized by sectors, circumferentially aligned, formed in radial partitions dividing the inner face of the ball to define therein hollow patterns. To better understand the object of the invention, there will be described below, purely by way of non-limiting illustration, an embodiment shown in the accompanying drawing.

On this drawing :

- Figure 1 is a front view of a ball according to the invention; - Figure 2 is an enlarged partial view, in section, of the ball of Figure 1;

- Figure 3 is a top view of a ball according to another embodiment of the invention;

- Figure 4 is a bottom view of the internal face of a hemisphere according to another embodiment;

- Figure 5 is a partial sectional view along a diametrical plane of a variant ball;

- Figure 6 is a partial sectional view of another variant. Figures 1 and 2 show a hollow metal ball according to the invention, made of stainless steel and having a weight of 700 g; it is designated by 1 as a whole. It is pointed out that the sectional representation of FIG. 2 is a false diametrical section, the neighboring and successive patterns never being centered on the same meridian circle; Figure 2 has been represented thus to facilitate understanding. The ball 1 consists of two hemispherical shells la and lb assembled by welding in a plane equatorial, the weld zone there constituting an annular zone devoid of patterns, which represents 6% of the base surface of the ball.

Each hemispherical shell 1a and 1b is externally limited by a spherical external face 2, the diameter of which is the diameter of the ball and equal to 75 mm, which envelops patterns 3 which are in relief relative to a spherical surface 4 known as the base the diameter of which is less than that of the external face 2. These independent relief patterns 3 are regularly distributed over the base surface 4; the minimum distance I between two patterns on the base surface 2 is 1.5 mm; the height p of the relief pattern 3, above the base surface 4, is 2 mm; the diameter d of the upper circular pattern 11 is 6.5 mm; each pattern is bordered laterally by a cylindrical surface 5. Each hemispherical shell 1a and 1b is internally limited by a spherical internal face 7, concentric with the external face 2; the difference between the radius of the external face 2 and the radius of the internal face 7 defines the thickness e of the ball, here 7 mm. The internal face 7 envelops patterns 8, in hollow, which project, perpendicular to the equatorial plane, fully and in line with the area occupied by each relief pattern 3, on the base surface 4. Each pattern is bordered laterally by a cylindrical surface and the diameter of the circular cross section of the cylinder bordering the pattern 8 is 5 mm; the depth of the recessed pattern 8, measured in the same way as the height of the relief pattern 3, is equal to this height, namely 2 mm. The ball carries 240 patterns, in total, on its external face 2 and on its internal face 7.

In FIG. 2, it can be seen that the relief patterns 3 on the external face 2 and the recessed patterns 8 on the internal face 7 are bordered by cylindrical surfaces 5, 9, the generators 6 and 21 of which are parallel and perpendicular to the equatorial plane 12 of the hemisphere la, to a draft angle, O \ for the relief patterns 3, and D2 for the hollow patterns 8.

All the relief patterns 3 have the shape of a circle and the same diameter d on the external face 2 of the ball 1. This is obtained by intersecting the spherical surface of the external face 2 by surfaces cylindrical 5 of elliptical contour in cross section, the major axis of the ellipse being equal to d and the minor axis having, whatever the position of the pattern on the external spherical face 2, a projection, along the generatrices 6, equal to d on side 2; this is imaged by the arc of a circle 20 in FIG. 2.

The ball shown in top view in FIG. 3 is designated as a whole by 100: the elements which differ from the first embodiment are referenced using the same references as those given in FIGS. 1 and 2 but increased by 100. This ball includes relief patterns 103 of trapezoidal shape, which are distributed over the base surface 4 along parallels 14 and along meridians 13, but staggered between one parallel and the other. The space f separating each pattern 103 is of constant width.

FIG. 4 shows another embodiment of the internal face of a ball according to the invention; the inner face shown in Figure 4 shows recessed patterns 108, partitioned by radial partitions 109 connected at their ends by circular areas 110, 111; such an arrangement also ensures good attenuation of the shock wave upon impact. Figure 5 is a partial view, in section, of the weld zone, annular devoid of patterns, of the two hemispherical half-shells la and lb of a ball according to the invention; the two equatorial half-zones 15a and 15b are chamfered by a bevel defining a space 17 intended to receive welding during the welding of the two hemispheres. An annular central groove 18a, 18b is hollowed out in the wall of the two hemispheres, in the equatorial plane, so as to receive a ring 16, to facilitate the relative centering of the two hemispheres; in the example shown, the section of the ring 16 and the grooves 18a and 18b is rectangular; this section could be circular, the ring then being an O-ring; in a variant not shown, the annular groove is discontinuous and materialized by sectors formed in the radial partitions 109, the ring being of diameter less than or equal to that of the internal face of the ball as suggested by the dotted lines 160 in FIG. 4 It has been found that the presence of such a ring, made of a material different from that of which the ball is made, contributes advantageously at the breaking of the shock wave upon impact of the ball.

FIG. 6 shows, in partial section, a variant of a ball, the external face of which has bosses 203, similar to the bosses 3 or 103 of FIGS. 2 or 3, while the internal face also includes bosses 209 which may be identical to the bosses 203 or different; the bumps 209 are not in line with the bumps 203 but offset, as shown in FIG. 6.

All the variants described above have the same advantages. It is found that the holding in hand of such a ball is very pleasant and prevents any slipping at the time of the throw; the ball has a satisfactory behavior for a "pointer": it rolls without random deviation from the path desired by the player; the ball also has a satisfactory behavior for a "shooter": it hits a target ball without any noticeable random deviation in the rebound and said rebound is clearly reduced compared to the balls of the state of the art, which allows an easier realization of a "square on the spot" where the launched ball takes, without rebound, the place of the struck target ball.

Obviously, we could have replaced all the relief patterns 3, 103 with hollow patterns.

These balls were made from circular sides with a diameter of 120 mm, which represent the developed surface of a hemisphere. The sides are transformed into half-spheres by stamping, which makes it possible to obtain hollow or raised patterns on the internal and / or external face of the ball. We then weld the two half-spheres and we resume, in machining, the ball obtained to eliminate, in particular, the irregularities in the equatorial zone where the weld bead is, and, if desired, give a color effect to the ball. In the above, the two hemispheres have been welded to form a spherical ball; of course, the connection of the two hemispheres could be achieved by screwing one hemisphere onto the other.

Excellent results have also been obtained by making the half-spheres in foundries, in a single operation. As a variant, not shown, when the metal used to manufacture the ball has a density which allows it, the ball is full, and its external face is analogous to the external faces of the hollow balls previously described.

Claims

1 - Ball, for boules, in particular for pétanque, comprising, on its external face (2), raised patterns (3, 103) relative to a base surface (4), regularly distributed over at least 90 % of the whole of said base surface (4), the surface occupied by all of the relief patterns (3, 103) on the base surface (4) representing at least 30% of said base surface (4) , characterized in that said relief patterns (3, 103) are bordered by substantially cylindrical surfaces (4) whose generatrices (6) are parallel, to a small angle, called clearance angle, D \).

2 - Ball according to claim 1, characterized in that each relief pattern (3, 103) occupies from 0.01% to 0.5% of the base surface (4), the surface of all the patterns in relief (3, 103) representing at least 70% of the external face (2). 3 - Ball according to claim 1, characterized in that all the relief patterns (3, 103) are connected to each other, revealing hollow patterns separated from each other, at the base surface ( 4), said recessed patterns occupying from 0.01% to 0.5% of the base surface (4), the surface of all of the recessed patterns representing from 10 to 70% of said external face (2) .

4 - Ball according to one of claims 1 to 3, characterized in that said ball (1) is hollow and has, on its internal face (7), hollow or relief patterns (8, 108) bordered by substantially cylindrical surfaces (9) whose generatrices (5) are parallel, to a small angle, called the draft angle, (D2).

5 - Ball according to one of claims 1 to 4. characterized in that the patterns (3, 103, 8) on the internal face (7) and / or external (2) of the ball (1) have a section straight line which decreases from the pole (11), half-spheres (la, lb) constituting the ball (1), to the equatorial plane (12).

6 - Ball according to one of claims 1 to 5, characterized in that the sections of the surfaces (5) cylindrical by the external face (2) of the ball (1) are substantially equal.

7 - Ball according to one of claims 1 to 4, characterized in that the patterns (103) on the external face (2) of the ball (1) have a trapezoidal shape and are distributed over the base surface (4 ) next meridians (13) and parallels (14) of the ball (1), leaving spaces of constant width (f) between each pattern (103) of trapezoidal shape.

8 - Ball according to one of claims 4 to 7, characterized in that each raised or hollow pattern (8) of the internal face (7) projects, according to said parallel generatrices (5), at least partially, on the area occupied on the base surface (4) respectively by a recessed or raised pattern (3, 103).

9 - Ball according to one of claims 4 to 8, characterized in that the poles (11) and / or the equatorial zone (15a, 15b) comprises (s) bosses (15) on the internal face (7) .

10 - Ball according to one of claims 4 to 9, characterized in that the patterns (108) are partitioned by radial partitions 109 on the internal face (7) of the ball (1). 11 - Ball according to one of claims 4 to 10, characterized in that an annular central groove (18a, 18b) is formed in the thickness of the wall of the two hemispheres located in the equatorial plane and receives a centering ring (16).

12 - Method for obtaining a ball produced by the assembly of two hemispherical shells obtained by forging or stamping, characterized in that the ball is according to one of claims 1 to 11, the clearance angles D \, D2) facilitating the release of the tool.

13 - Process for obtaining a ball produced by the assembly of two hemispherical shells obtained in foundry, characterized in that the ball is according to one of claims 1 to 11, the clearance angles ÇD \, D2) facilitating the release of the tool.