EP1199091A1 - Roller skate frame and process for making such a frame - Google Patents

Abstract

The frame (1), having a rectangular inverted U-shaped crosssection with one or more thrust surfaces (3, 4) to receive the sole of a boot, and one or more side flanges (2), is made from a cut-out sheet metal shape, stamped to form curved reinforcing ribs (8) in the flange(s), and then folded. The flanges have fixing holes (6) for blade, wheels or rollers, and the frame can be made from a number of components joined by screws, rivets or welding.

Description

The present invention relates to a frame for a sliding sport item of skate type with casters, ice skate and a method of manufacturing such a chassis.

Such elements must ensure the connection between the sliding member (s) proper, namely ice skate blade or wheels, casters, and the user's foot.

The chassis therefore generally consist of a bearing surface capable of receiving the athlete's shoe and one or two lateral flanges intended to receive the wheels, castors or the skate blade.

They must also have significant mechanical strength characteristics while being as light as possible so as not to cause excessive efforts on the part of the sportsman.

• une résistance mécanique et stabilité accrue, notamment pour les patins de vitesse mais également pour le patins dits de "Free ride", "Free style" ou hockey,
• une certaine flexibilité, notamment dans certaines zones du patin pour permettre une adaptation de la forme du patin à la trajectoire effectuée, notamment dans les courbes à grande vitesse,
• des formes variées et originales pour répondre aux exigences naissantes et changeantes de la mode,
• un coût de fabrication le plus bas possible.

Furthermore, the increasing technicality of these sliding sports articles, in particular in the case of inline skates, further increases the contradictory requirements which the skate frames must satisfy, namely:

• increased mechanical strength and stability, especially for speed skates but also for so-called "Free ride", "Free style" or hockey skates,
• a certain flexibility, in particular in certain areas of the skate to allow adaptation of the shape of the skate to the trajectory carried out, in particular in high-speed curves,
• varied and original shapes to meet the emerging and changing requirements of fashion,
• the lowest possible manufacturing cost.

The chassis manufacturing techniques currently known do not allow meet all these requirements, while maintaining a reasonable manufacturing cost.

Indeed, the oldest manufacturing technique consists in manufacturing such chassis with from a folded sheet, U-shaped, as shown for example in DE 10 33 569.

Such a manufacturing principle, admittedly inexpensive, does not however make it possible to obtain very varied forms, neither chassis of great mechanical resistance except to increase in a way important the thickness of the sheet and therefore its weight.

• coûts des moules,
• choix limité de matériaux pouvant être moulés,
• faibles caractéristiques de résistance mécanique de ces matériaux de moulage, même lorsqu'il s'agit de matériaux métalliques,
• précision insuffisante du moulage obligeant à des reprises d'usinage notamment en ce qui concerne l'alignement des trous de fixation des roues ou de la lame du patin pour un châssis à deux flasques.

Another commonly used technique consists in making the frames by molding from synthetic or even metallic material. Molding offers the advantage of allowing quite varied shapes, but also has many disadvantages:

• mold costs,
• limited choice of materials that can be molded,
• low mechanical strength characteristics of these molding materials, even in the case of metallic materials,
• Insufficient precision of the molding, which requires machining to be repeated, in particular as regards the alignment of the fixing holes of the wheels or of the skate blade for a chassis with two flanges.

We also know frames made of composite fibers. Such chassis can actually be made in almost all possible forms but they are of a extremely expensive manufacturing and difficult to industrialize. Furthermore, such chassis are certainly extremely rigid but lack flexibility and are therefore fragile and not very "Comfortable".

Finally, it has been proposed by US 5,388,846 to produce a frame for ice skating or casters from a metal profiled bar whose cross section corresponds to the desired general section for the chassis, the final shape of the chassis being obtained after machining with material removal.

Such a manufacturing process is still very expensive here, due to the machining time. required and the amount of material to be removed. It also does not allow great freedom in terms of shape or profile of the chassis.

The object of the present invention is to remedy these drawbacks and to provide a chassis improved for a sliding sports article and a method of manufacturing such a chassis which allows to solve the various problems stated above and which allows in particular to reconcile characteristics of mechanical strength, adaptability, flexibility of realization, lightness and low manufacturing cost.

This object is achieved by providing a chassis according to claims 4 to 13

• découper dans un flanc de métal une forme correspondant sensiblement à la forme développée d'au moins une partie du châssis,
• réaliser au moins une nervure de rigidification par emboutissage dans ladite partie du châssis.

This object is also achieved in the manufacturing process according to claims 1 to 3, in particular by the fact that it comprises the steps consisting in:

• cut a shape from a metal side roughly corresponding to the developed shape of at least part of the chassis,
• make at least one stiffening rib by stamping in said part of the chassis.

Indeed, the fact of stiffening the frame using ribs by stamping allows, by weight equal compared to a chassis simply obtained by folding, a significant increase in characteristics of rigidity and resistance to deformation due on the one hand to the presence of such ribs but also due to the localized work hardening of material obtained at the level said ribs related to the method of obtaining by stamping.

Depending on the desired result, it can be expected that each rib extends substantially over the entire length of the chassis flange, or only over a limited central area of each flange, or at the ends of each flange.

• la figure 1 est une vue de côté d'un châssis selon un premier mode de réalisation,
• la figure 2 est une vue en coupe selon II-II de la figure 1,
• la figure 3 est une vue en coupe selon III-III de la figure 1,
• la figure 4 est une vue de côté d'un châssis selon un second mode de réalisation,
• la figure 5 est une vue en coupe selon V-V de la figure 4,
• la figure 6 est une vue en coupe selon VI-VI de la figure 4,
• la figure 7 est une vue de côté d'un châssis selon un troisième mode de réalisation,
• la figure 8 est une vue en coupe selon VIII-VIII de la figure 7,
• la figure 9 est une vue en coupe selon IX-IX de la figure 7,
• la figure 10 est une vue en coupe selon X-X de la figure 7,
• la figure 11 est une vue de côté d'un chassis selon un quatrième mode de réalisation,
• la figure 12 est une vue en coupe selon XII-XII de la figure 11,
• la figure 13 est une vue similaire à la figure 12 illustrant encore un autre mode de réalisation.

In any case, the invention will be better understood and other characteristics thereof will be highlighted with the aid of the description which follows with reference to the appended schematic drawing representing, by way of nonlimiting examples, several forms of chassis production, and in which:

• FIG. 1 is a side view of a chassis according to a first embodiment,
• FIG. 2 is a sectional view along II-II of FIG. 1,
• FIG. 3 is a sectional view along III-III of FIG. 1,
• FIG. 4 is a side view of a chassis according to a second embodiment,
• FIG. 5 is a sectional view along VV of FIG. 4,
• FIG. 6 is a sectional view along VI-VI of FIG. 4,
• FIG. 7 is a side view of a chassis according to a third embodiment,
• FIG. 8 is a sectional view along VIII-VIII of FIG. 7,
• FIG. 9 is a sectional view along IX-IX of FIG. 7,
• FIG. 10 is a sectional view along XX of FIG. 7,
• FIG. 11 is a side view of a chassis according to a fourth embodiment,
• FIG. 12 is a sectional view along XII-XII of FIG. 11,
• Figure 13 is a view similar to Figure 12 illustrating yet another embodiment.

As shown in Figures 1 to 3, the chassis according to the invention is made from a sheet metal and is generally in the form of two lateral flanges 2 connected one to the other by two platforms 3, 4, giving the whole a cross section substantially U-shaped.

Each of the platforms 3, 4 constitutes a bearing surface capable of receiving the shoe of the sportsman, the latter (not shown in the drawing) being fixed by any means known in self and in particular glue, rivets, screws, etc., but which can also be fixed so removable by means of non-permanent connection.

It will also be noted that the platforms 3, 4 are distinct and separate from each other by a cutout 5, and located at different levels in height, the platform 4 being more low than platform 3, to take account of the natural position, heel slightly raised, of a sportsman.

Each flange 2 has an elongated shape and slightly curved in an arc of a circle in the longitudinal direction.

Holes 6 are provided at the lower end of each flange for fixing the casters or as the case may be, a skate blade.

Each hole 6 is made in a cylindrical boss 7 which can be obtained by stamping. The holes 6 located in correspondence in the two flanges 2 are coaxial.

Each flange 2 also has a stamped rib 8 extending substantially over the entire length of said flange 2, above the fixing holes 6 and of generally arched appearance.

As shown more particularly in Figures 2 and 3, each rib 8 has a substantially constant thickness corresponding to that of the sheet metal constituting the flanges 2 and each of the platforms 3, 4, and has a hollow shape, curved outwards, this hollow shape and constant thickness being characteristic of a shape obtained by stamping.

Each rib 8 also preferably follows the contour of the flanges 1, 2, on which it is stamped and therefore has in this case an elongated shape and also slightly curved in the longitudinal direction.

Such a stamped rib 8 gives the flange on which it is made a significant increase in moment of inertia and resistance to deformation as well in longitudinal direction than vertical, this increase being linked not only to the presence of each rib 8 and its shape but also the hardening of the material at level of the rib during the stamping operation.

Such a concept of construction and manufacturing practically makes it possible to divide by two the thickness and therefore the weight of the sheet metal plate used to make the chassis relative to a folded, molded or profiled chassis, while retaining or even increasing the characteristics mechanical.

By this process, an extremely light, resistant and inexpensive chassis is therefore obtained.

Advantageously, the frame will be made from a laminated sheet whose fibers are are oriented in the longitudinal direction of the chassis. Such a characteristic allows also to increase the resistance qualities of the chassis in the longitudinal direction, especially compared to an injected or cast alloy chassis in which there is no fiber formation.

Furthermore, it is possible to modify / modulate the moment of inertia of the chassis by the forecast of cuts such as 5, 9, appropriate.

In the present case, the cutout 9, of oval shape and disposed centrally below the rib 8, makes it possible to reduce the bending stiffness of each flange 2 in the central zone of the chassis and, in combination with the cutout 5 also centrally arranged, allows also to reduce the bending stiffness of the entire chassis in this area.

• tout d'abord le flanc est prédécoupé à une forme correspondant à la forme développée du châssis avec une surface augmentée au niveau de la zone de chaque nervure pour tenir compte du phénomène de retrait de matière au moment de l'emboutissage,
• au cours de cette première opération, toutes les découpes telles que 5 et 9 sont également réalisées,
• ensuite les deux nervures 8 des deux flasques 1,2 sont réalisées par emboutissage,
• puis les trous 6 sont réalisés par filage et sont éventuellement taraudés, après une opération préalable de matriçage des bossages 7,
• et enfin la tôle est pliée en U.

Such a chassis can be obtained very simply and in a single piece from a metal sidewall by the following succession of steps:

• first of all, the flank is precut to a shape corresponding to the developed shape of the frame with an increased surface at the level of the zone of each rib to take account of the phenomenon of shrinkage of material at the time of stamping,
• during this first operation, all the cuts such as 5 and 9 are also made,
• then the two ribs 8 of the two flanges 1,2 are produced by stamping,
• then the holes 6 are produced by spinning and are optionally tapped, after a prior operation of stamping the bosses 7,
• and finally the sheet is folded into a U.

Of course, the sequence of operations described above is only applicable if the chassis is made in one piece from the same metal side.

It can also be obtained in several parts assembled by any means known in such as screws, rivets, welds, ... etc.

More specifically, each chassis can consist of two section flanges general cross in the shape of "L" and connected together by the small branch of each "L".

Compared to an aluminum alloy chassis obtained by injection molding, such manufacturing technique by stamping, and possibly stamping, bending, is much more precise, does not require a subsequent machining operation and provides a choice of more important material and with more interesting characteristics. Indeed, the number materials available for injection or molding is very limited and these materials are generally brittle and do not give rise to the formation of fibers.

In addition, since molding and injection techniques are not precise enough, rework always long and costly machining would be necessary to achieve for example the fixing holes of the sliding member (s).

It will also be noted that the geometric qualities of a stamped chassis are clearly superior to those of a plastic chassis, for which we are confronted by the fact significant shrinkage of the material, twisting phenomena and hole alignment wheel fixing requiring resumption of machining operations.

• matière plastique   15 secondes
• aluminium profilé + usiné   180 secondes
• aluminium coulé   85 secondes
• aluminium embouti   6 secondes

As an indication, the times required to produce a chassis in the various techniques can be evaluated as follows:

• plastic 15 seconds
• profiled aluminum + machined 180 seconds
• cast aluminum 85 seconds
• stamped aluminum 6 seconds

There is therefore a triple gain in time and cost of manufacture, characteristics of the material and lightness, produced using the stamping technique according to the invention.

Another extremely advantageous feature of the stamping technique is in that the design possibilities are greater than those of the profile aluminum which does not allow any relief or shape on the sides of the profile necessarily plans.

Furthermore, the method and the construction of the chassis according to the invention offer great advantages. possibilities to vary the moment of inertia of the chassis along the longitudinal axis of this, by predicting the ribbing, cutouts or even flank heights, in order to obtain a deformation of the chassis and an optimum behavior of the skate depending on the type desired practice.

Thus, the chassis described with reference to FIGS. 1 to 3 offers almost uniform rigidity over its entire length while the other two examples of chassis shown in Figures 4 to 6 and 7 to 10 allow to obtain different behaviors.

The chassis 10 shown in FIGS. 4 to 6 comprises, like the chassis 1, two flanges side 12 but a single platform 13 extending over its entire length.

The chassis 10 also has a shape clearly curved in an arc.

Each flange 12 has at each end a cutout 15 and a narrowing perimeter 14, giving it a certain flexibility and a low moment of inertia in these areas.

On the other hand, each flange 12 is provided in its median zone with two ribs stamped 18.19 superimposed.

Such a chassis therefore has very high rigidity in the center, in the region of the ribs. 18, 19, and relatively flexible ends.

The chassis 20 shown in FIGS. 7 to 10 comprises, like the chassis 10, two flanges side 22 and a single platform 13 extending over its entire length.

• à son extrémité arrière, deux nervures superposées 28, 29,
• dans sa zone centrale une découpe 25 ainsi qu'un rétrécissement périmétrique 24,
• à son extrémité avant, une seule nervure 27.

It also has an arc shape. Each flange 12 has:

• at its rear end, two superimposed ribs 28, 29,
• in its central zone a cutout 25 as well as a perimeter narrowing 24,
• at its front end, a single rib 27.

Such a chassis will therefore be very rigid at the rear, very flexible at the center and moderately rigid. in the front.

Figures 11 to 13 illustrate yet other embodiments of a chassis.

In the case of FIGS. 11 and 12, each lateral flange 32 of the chassis 30 is stamped on its entire surface and therefore constitutes a wide and single rib 38 slightly curved towards outside.

Such a chassis therefore has characteristics of torsional and flexural rigidity particularly uniform over its entire length, the only more flexible areas being defined at the front and rear by notches 34.

Finally, FIG. 13 illustrates yet another example of cross stamping of the flanges sides 42 of a chassis 40, in which each flange is pressed for the first time towards the outside, then a second time inwards, thus defining two external "ribs" 48 and an inner midrib 49.

Of course, a simple stamping of each inner rib 49 is also possible.

Of course, the present invention is not limited to the exemplary embodiments shown above. It can be applied to any chassis for sporting goods which must meet the same requirements.

Claims (13)

Method for manufacturing an aluminum frame for a sliding sports article and of the type comprising at least one bearing surface (3, 4, 13, 23) capable of receiving a shoe and at least one lateral flange (2, 12 , 22) comprising fixing means (6, 16, 26) of the sliding member (s), characterized in that it comprises the steps consisting in: cut a metal side shape substantially corresponding to the developed shape of at least one part (2, 12, 22) of the frame to produce at least one rib (8, 9, 18, 19, 28, 29) for stiffening by stamping in said part of the chassis. Manufacturing method according to claim 1, characterized in that it consists in cutting the total developed shape of the chassis and in obtaining the final shape after bending into a U after the stamping operation. Manufacturing method according to claim 1, characterized in that the chassis consists of several parts assembled by screws, rivets or welding. Chassis for sliding article comprising at least one bearing surface (3, 4, 13, 23) capable of receiving a shoe and at least one lateral flange (2, 12, 22) comprising fixing means (6, 16, 26) of the sliding member (s), characterized in that said at least one flange (2, 12, 22) is made of aluminum and in that said flange comprises at least one rib (8, 9, 18, 19, 28 , 29) of stiffening produced by stamping Chassis according to claim 4, characterized in that said at least one rib (8, 9, 18, 19, 28, 29) extends substantially in the longitudinal direction of said at least one flange and is produced above the fixing means ( 6, 16, 26) of the sliding member (s). Chassis according to one of claims 4 or 5, characterized in that said at least one rib (8, 9, 18, 19, 28, 29) has a substantially arcuate shape. Chassis according to one of claims 4 to 6, characterized in that said at least one rib (8) extends substantially over the entire length of said at least one flange of the chassis. Chassis according to one of claims 4 to 6, characterized in that at least one cutout (9) is associated with said at least one rib (8). Chassis according to one of claims 4 to 6, characterized in that said at least one rib (18, 19) extends only over a limited central area of said at least one flange. Chassis according to one of claims 4 to 6, characterized in that said at least one rib (28, 29) extends at the ends of said at least one flange. Chassis according to claim 4, characterized in that said at least one rib (38) extends substantially over the entire surface of said at least one lateral flange (32). Chassis according to any one of Claims 4 to 11, characterized in that each rib extends towards the interior of the chassis. Chassis according to any one of Claims 4 to 12, characterized in that each rib extends towards the outside of the chassis.

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