ES2729338T3 - Shovel, in particular, paddle shovel structure - Google Patents

Abstract

Shovel that includes, on the one hand, a core (5) coated on each of its faces parallel to the striking surfaces of the blade by at least one reinforcing layer (9a, 9b) and, on the other hand, a tubular element (6) forming the perimeter of the blade, said tubular element being constituted by a composite braid in which an inflatable sheath is inserted, characterized in that at least one additional reinforcing element (8) is positioned between the peripheral surface (5c ) of the core (5) and the tubular element (6).

Description

DESCRIPTION

Shovel, in particular, paddle shovel structure

The invention relates to a shovel, which allows a ball to be struck and which has no string. In particular, it is intended for the paddle game.

The Paddle is a ball game that is played with a shovel without strings, whose hitting area is solid or almost solid, since it can include some transverse holes transversely of the blade head. The paddle game is played on a ground separated by a net and surrounded by walls, the ball must bounce on the ground and can also bounce on the walls.

The paddle shovel is made up of three parts, which are the head, the heart and the handle. The head corresponds to the hitting area of the ball, the handle corresponds to the part that the player holds with the hand and the heart is the area that joins the head to the shovel handle.

In general, the paddle blades comprise a core coated on each of its two striking faces in the striking or head area of the blade by a reinforcement generally made of composite material. On the other hand, a generally hollow tube surrounds the head of the blade and the two ends of this tube meet at the level of the handle, as described in Spanish document ES 2395 181. This hollow tube directly surrounds the perimeter of the core of the shovel. This tube takes its hollow shape during the molding of the blade and, in particular, thanks to an inflation operation of this tube. This hollow tube has an outer surface that forms the perimeter of the blade head that reproduces the shape of the mold used during molding. On the other hand, its inner surface in contact with the perimeter of the blade core is not always regular and can present deformations or bends, which frequently induces defects and damages the resistance of the blade.

Also, to remedy these drawbacks, the purpose of the invention is to propose a particular internal blade structure that allows to obtain a well formed tube or tubular element. Another purpose of the invention allows to increase the resistance of the blade.

More precisely, the invention is about a blade that includes, on the one hand, a core coated on each of its faces parallel to the striking surfaces of the blade by at least one reinforcing layer and, on the other hand, a tubular element that forms the perimeter of the blade, said tubular element being constituted by a composite braid in which an inflatable sheath is inserted.

In accordance with the invention, this blade is characterized in that at least one additional reinforcing element is positioned between the peripheral surface of the core and the tubular element.

In other words, the peripheral surface of the core or the perimeter of the core that is intended to give the blade its thickness, is directly or indirectly covered, partially or totally, by an additional reinforcing layer, called an additional reinforcing element, on the one that comes to rest on its inner surface a tubular element that forms the perimeter of the blade head and which can also extend to the handle of the blade.

In other words, an additional reinforcing element is interposed between the inner wall of the tubular element and the core, preventing the sinking of the core during the expansion of the tubular element.

According to advantageous, but not mandatory, aspects of the invention, the blade according to the invention can incorporate one or more of the following characteristics.

The additional reinforcing element is preferably stiffer than the core material.

The additional reinforcing element may consist of a band in contact with the peripheral surface of the core or perimeter of the core.

This band may include parallel edges and may have a width substantially corresponding to the thickness of the core.

The additional reinforcing element may only partially cover the peripheral surface of the core. In other words, the length of the band that forms the additional reinforcement element is less than the perimeter of the core. On the other hand, the additional reinforcing element can completely cover the peripheral surface of the core.

The blade may also include a second tubular element at the level of its heart that rests on a part of the additional reinforcing element.

The blade can have two additional reinforcement elements superimposed or even a larger number if necessary.

An elastomeric element may be superimposed on the additional reinforcement element or on one of the additional reinforcement elements.

The additional element may also include some emptyings. In particular, these emptyings may be small through holes of various shapes and small dimensions, of the order of a few millimeters. The blade according to the invention can have a core formed by several superimposed layers and / or it can have a core formed by several parts fitted together.

The blade according to the invention can also have a structure in which the reinforcing layers and the tubular element are covered by a protective layer.

The blade according to the invention generally has a tubular element that is a hollow tube.

During the manufacture of the blade according to the invention, the blade comprising, on the one hand, a core coated on each of its faces that form striking surfaces by at least one reinforcing layer and, on the other hand, a tubular element that the perimeter of the blade forms, an additional reinforcing element is positioned on the blade mold on the peripheral surface of the core, the core having previously been positioned on the mold. Then, around this additional reinforcing element, a composite braid is positioned in which an inflatable sheath is inserted, such as during the inflation and molding operation, the composite braid forms a hollow tube whose inner wall is directly or indirectly supported against the additional reinforcing element to correctly form the tubular element.

During the manufacture of the blade, the additional reinforcing element is trimmed in the form of a band. This band trimming can be carried out either prior to molding, or during the molding phase of the different elements constituting the blade.

The invention will be described below, with reference to the accompanying drawings, given by way of example only, not limitation, in which:

- Figure 1 is a top view of the blade according to the invention.

- Figure 2 is an exploded perspective view of the different constituent elements of the blade according to a first embodiment of the invention.

- Figure 3 is an incomplete sectional view taken in the main symmetry plane of the blade according to the first embodiment of the invention, the lower and upper reinforcement elements not being, as well as the lower and upper protection layers represented.

- Figure 4 is a partial section according to A-A of the blade according to the first embodiment of the invention. - Figure 5 is an exploded perspective view of the different constituent elements of the blade according to a second embodiment of the invention.

- Figure 6 is a partial section according to A-A of the blade according to the second embodiment of the invention. - Figure 7 is a perspective view of two internal elements to the blade according to a variant embodiment. - Figure 8 is a perspective view of two internal elements to the blade according to another variant embodiment. As illustrated in Figure 1, the paddle paddle is composed of a head 1 or sieve that constitutes the hitting area of the ball, a handle 2 intended for the player to grab by hand and a heart 3 that it joins the head 1 to the handle 2. This zone of heart 3 has an emptying 4. It could be considered that this zone 3 presented several emptyings and, for example, three emptyings 4a, 4b, 4c, as illustrated in figures 2 and 5 or even no emptying: the zone of the heart 3 would, then, in this case, be completely solid. In general, the head of a paddle blade has some through holes not shown, to avoid resistance to friction in the air and make the blade more manageable.

A first embodiment of the invention is illustrated in Figures 2 to 4. The structure of the blade head 1 is constituted by a central core 5 coated on its two lower flat faces 5b and upper 5a respectively by two layers of materials compounds 9b and 9a. These layers are themselves covered respectively by two protective layers 10b and 10a that form the striking surfaces. In other words, the lower 5b and upper faces 5a of the core 5 are located in planes parallel to the striking planes of the shovel. The protective layers 10a and 10b can be constituted either by layers of plastic material, transparent or not, positioned in the mold before molding or also incorporated after molding the blade by gluing, either by additional layers of paint or varnish applied after the molding of the blade, directly on the layers of compound 9a and 9b. These layers are, in general, of a fine thickness of the order of the millimeter and even less than 1 mm. These protective layers and these composite layers extend, in the illustrated embodiment mold, in the area of the heart 3 of the blade and, likewise, on the handle 2 of the blade.

The layers of composite materials 9a, 9b may consist of one or more elements, juxtaposed and / or superimposed. The composite materials used can be based on glass fibers, Carbon fibers, Aramid fibers or also natural fibers, used alone or in combination. The fibers can be unidirectional, but in an advantageous embodiment, the fibers are crossed and oriented, generally at 0 and 90 degrees with respect to the longitudinal axis of the handle 2. These fibers are impregnated with resin, such as epoxy resin. During molding, the resin ensures the bonding of all the constituent elements of the blade to each other.

The core 5 of the blade is composed of a layer of generally thermoplastic polymer foam, such as, for example, a Vinyl Acetalo or eVa ethylene foam. These foams are of low density and of low hardness, preferably between 10 and 30 Shore A. A foam of this type is flexible and deformable and, therefore, has a low stiffness, being Young's modulus of a foam of this type. type, for example, less than 500 MPa. This core, substantially oval in a plane parallel to the striking surfaces, gives the blade a sandwich structure separating the layers of composite materials 9a and 9b from the thickness of the core 5. The thickness of this core 5 is, in general , large, between 10 and 50 mm, preferably between 35 and 40 mm.

It will not leave the scope of the invention if the core is constituted by several parts that fit into each other and / or if this core is constituted by several superimposed layers.

The perimeter of the core 5 is constituted by the peripheral surface 5c of the core 5. This peripheral surface 5c of the core 5 is covered by several elements detailed below that form and reinforce the perimeter of the blade.

In fact, the peripheral surface 5c of the core is at least partially covered by a reinforcement band 8 or additional reinforcement element 8, then by a tubular element 6 which covers the outer face of this reinforcement band 8. This tubular element 6 it forms the perimeter of the blade head and also extends to the level of the handle 2 by two rectilinear portions 6e and 6d.

The additional reinforcing element 8 is constituted by a much stiffer material than the foam constituting the core 5, as, for example, by Aluminum, by a compound based on fiberglass or Carbon fibers or also by a plastic material Rigid ABS type, preferably loaded with fiberglass, more rigid than EVA. Young's modulus of the material of the additional reinforcing element will be, for example, greater than 3,000 MPa, preferably greater than 8,000 MPa and even more than 10,000 MPa. In fact, the greater the stiffness of the additional reinforcement element 8, the more regular and well formed will be the section of the tube 6 and, in particular, the inner surface 6b of the tube 6. The thickness of this additional reinforcement element 8 is thin , of the order of the millimeter, for example, between 0.2 and 1.5 mm so as not to significantly increase the weight of the blade.

This additional reinforcing element 8 is positioned at least on the front part of the head 1 of the blade and, likewise, preferably extends over the lateral edges of the blade to the level of the heart 3 of the blade, as illustrated in the Figure 3. In another embodiment, this additional reinforcing element 8 can completely turn around the core 5. In particular, in the case where the blade has a second tubular element 7 in the area of the heart 3 and eventually extends by the handle 2, as illustrated in figure 3, this could allow this second tubular element 7 of the blade to find support on the face in front of the peripheral reinforcement 8. In a preferred mode, this additional reinforcing element 8 is a band directly in contact with the core.

This additional reinforcing element 8 is positioned between the peripheral surface 5c of the core 5 and the inner wall 6b of the tubular element 6. The tubular element 6 or tube 6 is constituted by a braid of composite materials based on glass oriented fibers and / or of Carbon and / or possibly of resin impregnated Aramid in which an inflatable sheath is inserted which, during the molding of the blade takes the form of a tube due to the effect of inflation of this sheath. As illustrated in Figure 4, this tube 6 is hollow and its section has an arcuate area 6a that takes the shape of the blade mold on its outer face turned outward from the blade and a substantially rectilinear area 6b on its face inside turned towards the center of the sieve of the blade that adopts the outer shape of the peripheral surface 5c of the core 5. This substantially rectilinear area of the tube 6 is obtained by the fact that the tube 6 takes support on the band 8 which is the rigid enough not to undergo deformations when pressure is exerted on the walls of the tube 6 during inflation during molding. This reinforcement band 8 therefore allows to obtain a tube 6 that has a regular internal wall or inner wall 6b, without undulation and without folds. In fact, when the tube 6 rests directly against the peripheral surface 5c of the core 5, as usual in the paddle blades of the prior art, the inner wall 6b of the tubular element 6 is not formed correctly during inflation and molding and It has defects that result in one or several undulations or folds due to the crushing of the peripheral surface of the core 5, the core constituent material 5 being too flexible and deformable. These prior art blades present, then, a often, areas of fragility and poor resistance to the level of the perimeter of the blade. These manufacturing defects also create appearance defects that appear on the perimeter of the blade. To avoid these disadvantages, the invention therefore proposes to position at least one additional reinforcing element 8 between the peripheral surface 5c of the core 5 and the tubular element 6.

Due to this fact, during the inflation phase during the molding of the blade, the tube 6 rests against the rigid wall of the mold to form its outer or outer wall 6a and against the additional reinforcing element 8 to form its inner wall or interior 6b.

As illustrated in Figure 2, the additional reinforcing element 8 is a band that preferably has a width substantially corresponding to the thickness of the core. The sides of this band then become adjacent to the lower and upper reinforcements 9a and 9b located in planes parallel to the striking planes. In a variant embodiment, the peripheral reinforcement 8 could be formed by an extension of one or both of the lower and upper reinforcements that would be curved to adopt the perimeter of the core.

In another variant, likewise, the reinforcing band 8 could be of slightly smaller or greater thickness, in order to provide a sufficient bearing surface to form the inner face 6b of the tube 6. In the case where the width of this band is greater than the width of the core, a part of this band could cover more or less partially, the lower or upper surfaces 5b and the core 5a.

This band 8 preferably has lower and upper edges, 8i and 8s parallel and rectilinear, but it may also be convenient to have edges carved by notches of little depth.

As already indicated above, the tubular element 6 has two ends 6d and 6e that form a part of the handle. The inner part of the handle is completed by a second tubular element 7 or additional tube 7 that constitutes a part of the heart of the blade to stiffen this part of the blade. However, the frame of the invention will not leave if the blade does not have this additional tube 7. This additional tube 7 enters its upper part in contact with the lower part of the core. Also, in an advantageous embodiment, it is interesting that the additional reinforcement element 8 is extended to the level of the lower part of the core to allow the additional tube 7 to rest against the additional reinforcement element 8 during its inflation and during molding to obtain a hollow tube 7 formed correctly in the area of the heart, without having deformed the core 5 of the blade during molding.

Figures 5 and 6 present a second embodiment in which it is considered to superimpose on the additional reinforcement element 8 a second additional reinforcement element 8a with the main purpose of increasing the rigidity of the interface constituted herein by the two elements 8 and 8a and positioned between the perimeter of the core 5 and the inner face 6b of the tube 6. In this way, the inner face 6b of the tube rests on an even stiffer surface than in the first embodiment and this face is, Then, even better formed. This second additional reinforcing element 8a may be a band of a length similar to the length of the band formed by the element 8 or may be of a shorter length and be positioned superimposed on the element 8 in a particular area where the tube conformation 6 is more delicate.

Figure 7 is a variant embodiment showing a band 8b constituted by an elastomeric element designed to dampen the blade during ball hitting. This band 8b is superimposed on the additional reinforcement element 8 and comes into contact with the inner face 6b of the tube 6. This elastomeric element 8b may have a length similar to the band 8 or possibly shorter. In this case, the tubular element 6 does not rest directly on the additional reinforcement element 8 in some areas, but this does not impair the good formation of the section of the tube 6, since the tubular element 6 finds, however, a rigid support of the side of the core 5, which still prevents the core 5 from deforming in the course of molding.

Figure 8 is another variant embodiment in which one of the two additional reinforcement elements 8 and 8c can have recesses 8d intended to lighten this additional reinforcement element. The number of recesses 8d, as well as the size of the recesses 8d will be chosen such that these recesses do not alter the conformation of the inner wall 6b of the tube 6. These recesses can be without exit or, on the contrary, totally through. The shape of the hollows or holes can be diverse, round or oval or polygonal. The distribution of these emptyings on the band may be a particular reason, distributed regularly or not.

As regards the manufacturing process of the blade, it is as follows.

At the bottom of the mold they are positioned successively

- the lower protection layer 10b,

- the lower reinforcement layer or layers 9b,

- core 5.

Then, around this core 5 they are positioned successively

- the additional reinforcement element (s) 8,

- the composite braid 6 in which an inflatable sheath is inserted,

- the composite braid 7 in which an inflatable sheath is also inserted.

Then, also above core 5, they are positioned successively

- the upper reinforcement layer or layers 9a,

- the upper protection layer 10a.

And, finally, the assembly is covered by the cover of the mold that goes into support against the bottom of the mold. After closing the mold, the molding of the blade is carried out by application of known pressure and temperature parameters combined with an operation of inflation of the covers inserted inside the composite braids 6 and 7 to obtain the hollow tubes 6 and 7 During this molding and inflation operation, the inner wall of the hollow tube 6 rests against the additional reinforcement element 8 which, due to its sufficient rigidity, does not crush and does not deform, which allows the tube hollow is formed correctly, without presenting areas of poor resistance to breakage.

It will not go beyond the scope of the invention if the blade does not have a composite braid 7 that forms the tube 7. Without this element, the manufacturing process is then slightly simplified, since the molding has a lesser element.

The additional reinforcing element 8 that surrounds the perimeter of the core 5 can be arranged around the core 5 during the molding, with or without gluing means or it can also be positioned around the core before molding, by gluing or by superinjection on the perimeter of the core 5 in the area of the perimeter of the core 5 in question.

The invention has the advantage that it solves manufacturing problems and, in particular, that it solves the problems encountered to correctly form the peripheral tube and, in particular, its inner wall closest to the core, which is a substantial constituent element of the structure of a paddle shovel. The invention presents a simple, economical solution and without the addition of excessive weight. In addition, depending on the dimensions, according to the materials used for the additional reinforcement, as well as the number of additional reinforcements, it is possible to intervene on the behavior of the blade during the striking of the ball, as well as on the resistance of this blade.

Claims (16)

1. Shovel that includes, on the one hand, a core (5) coated on each of its faces parallel to the striking surfaces of the blade by at least one reinforcing layer (9a, 9b) and, on the other hand, a tubular element (6) that forms the perimeter of the blade, said tubular element being constituted by a composite braid in which an inflatable sheath is inserted, characterized in that at least one additional reinforcing element (8) is positioned between the peripheral surface (5c) of the core (5) and the tubular element (6). 2. Shovel according to claim 1, characterized in that the additional reinforcing element (8) is more rigid than the core material (5). 3. Shovel according to claim 1 or 2, characterized in that the additional reinforcing element (8) is a band in contact with the peripheral surface (5c) of the core (5). 4. Shovel according to claim 3, characterized in that the reinforcement band (8) includes parallel edges and that the width of this reinforcement band (8) substantially corresponds to the thickness of the core. 5. Shovel according to claim 1, characterized in that the additional reinforcing element (8) only partially covers the peripheral surface (5c) of the core (5). 6. Shovel according to claim 1, characterized in that the additional reinforcing element (8) completely covers the peripheral surface (5c) of the core (5). 7. Shovel according to one of the preceding claims, characterized in that it includes a second tubular element (7) at the level of its heart (3) that rests on a part of the additional reinforcing element (8). 8. Shovel according to claim 1, characterized in that it includes two additional reinforcement elements superimposed (8, 8a). 9. Shovel according to claim 1, characterized in that an elastomeric element (8b) is superimposed on the additional reinforcing element (8). 10. Shovel according to claim 1, characterized in that the additional element (8, 8b, 8c) has hollows (8d). 11. Shovel according to one of the preceding claims, characterized in that the core (5) is formed by several superimposed layers and / or is formed by several parts fitted together. 12. Shovel according to one of the preceding claims, characterized in that the core (5) is formed by several parts fitted together. 13. Shovel according to one of the preceding claims, characterized in that the reinforcing layers (9a, 9b) and the tubular element (6) are covered by a protective layer (10a, 10b). 14. Shovel according to one of the preceding claims, characterized in that the tubular element (6) is a hollow tube. 15. Method of manufacturing a blade comprising, on the one hand, a core (5) coated on each of its faces that form striking surfaces by at least one reinforcing layer (9a, 9b) and, on the other hand, a tubular element (6) that forms the perimeter of the blade characterized in that an additional reinforcing element (8) is positioned on the mold of the blade on the peripheral surface (5c) of the core (5), the core having been positioned ( 5) previously in the mold, then, around this additional reinforcing element (8), a composite braid is positioned in which an inflatable sheath is inserted, such as during the inflation and molding operation, the composite braid forms a hollow tube whose inner wall (6b) leans directly or indirectly against the additional reinforcing element (8) to correctly form the tubular element (6). 16. Method of manufacturing a blade according to claim 15, characterized in that the additional reinforcing element (8) is cut in the form of a band.