EP0367684A2 - Method and apparatus for waxing skis - Google Patents

Abstract

According to the invention, a thermoplastic coating material in solid form is continuously conveyed into a heating and spreading block (1), the material being progressively softened in the block and conveyed in liquid form under the block in order successively to be distributed, flattened and spread on the runner (12) of the ski, then expelled under pressure by a transverse scraper (14) which is integral with the spreading block (1). The scraper (14) is a steel bar of rectangular cross-section, the lower edge (16) of which extends slightly below the lower surface (8) of the spreading block (1). The extension of the lower edge, the inclination of its front surface, the speed of displacement and the pressing force are chosen in an appropriate manner. …<IMAGE>…

Description

The present invention relates to a method and a device for molding by scanning ski soles made of thermoplastic material.

The development of thermoplastic resins as a coating constituting the sole or sliding surface of skis has led to the development of machines for carrying out repair or renovation operations on these ski soles, in order to restore a surface condition free of roughness or cracks and restore the original mechanical characteristics to these coatings.

Such processes and devices for molding ski soles are already known, described for example in patent FR-A-2 391 054. In such a known method, a thermoplastic filler material is continuously fed in a solid form. heating body shaped as a display shoe, the filler material being gradually softened in the heating body and conveyed in liquid form under the shoe to be crushed and spread on the ski sole during the sweeping or longitudinal translation movement skating on the ski. The device for implementing this process comprises means for supplying thermoplastic filler material, a heating body with a display shoe shaped to receive the filler material in solid form, for heating and softening it gradually, to bring it in liquid form under a distribution and spreading structure intended to be pressed against the ski sole and to be driven in longitudinal translation on said ski sole in a preferential direction of propagation. The skate has a projection for preheating the ski sole upstream of the distribution structure.

The material constituting the ski soles is generally a polyethylene. To produce an overmolding having sufficient bonding properties on the preexisting sole, polyethylene in solid form, strip, wire or granule is generally used as thermoplastic filler material.

For some time, to increase the sliding qualities of skis, manufacturers have developed gliding soles in very high molecular weight polyethylene. Such ski soles are obtained by sintering, and formed by slicing. The sliding qualities thus obtained are superior to those produced with polyethylene of lower molecular weight, such as polyethylenes hot molded at a temperature above the softening point.

It can be seen that, when such a very high molecular weight polyethylene sole is molded using a known overmolding device, which covers said sole with a film of molten polyethylene, a large part of the advantages are lost. of the initial sole made of very high molecular weight polyethylene, and in particular it loses its superior sliding power. The known devices lead in fact to completely cover the preexisting sole with a film of molten polyethylene, a film which is then reduced by planing and sanding.

Attempts have been made to reduce the adverse effects of overmolding by reducing the final surface area of the melt-deposited polyethylene. The Applicant has thus attempted to reduce this surface by subsequent machining of the overmolded sole until the flat parts of very high molecular weight polyethylene appear, leaving the molten polyethylene only in the hollow areas which justified overmolding. This attempt has however shown that the result obtained is disappointing, because we do not find the sliding qualities of the initial sole.

Such a method also leads to a significant loss of material, since the known methods and devices for overmolding require depositing a layer of thermoplastic material of sufficient thickness, and most of this thickness must then be removed.

The object of the present invention is in particular to produce a molding of the ski sole by sweeping, making it possible to conserve the sliding qualities of the material constituting the original sole as much as possible, while avoiding recharging the flat parts of the soles with thermoplastic material. ski, and by sufficiently recharging the hollow parts of the soles. The difficulty is in particular to sufficiently recharge the hollow parts of the soles, in order to avoid obtaining hollow parts again after removal of the overmolding material on cooling.

The present invention also aims to reduce as much as possible the heating time of the very high molecular weight polyethylene forming the initial sole to be molded. The reduction of the heating time implies an increase in the speed of translation of the overmolding device relative to the ski sole, speed which tends to reduce the time required for overmolding and therefore to increase the production rate.

A first attempt may consist in increasing the heating power of the resistors housed in the display pad, in order to increase its temperature and to increase the heating rate of the plastic filler material and of the sole to be molded. It turned out, however, that such an attempt leads to failure, because it makes it possible to slightly increase the scanning speed, but the layer of polyethylene deposited acting as thermal mattress still keeps the heat on the ski sole for too long. . A more appreciable increase in the power and the heating temperature leads to the deterioration of the filler material, and the production of fumes, in particular during the downtimes between two overmolding operations.

In addition, the aims sought by the invention must not lead to a reduction in the quality of the overmolding obtained, or the distribution of the material deposited on the sole.

Another object of the invention is to provide a semi-automatic overmolding device, ensuring by itself the relative transfer of the ski and the overmolding device; according to the invention, it is sought to reduce the size of the device, and in particular to design such a device having a size significantly less than the length of the ski. This requires new means ensuring the maintenance of the ski and its transfer at a regular speed in the device.

To achieve the desired effects as well as others, in a molding head, the thermoplastic filler material is successively heated in heating channels, introduced into a transverse distribution groove formed on the underside of the skate structure. display, crushed and spread on the ski sole by a display surface, and, at the end of the display area under the display shoe, the thermoplastic filler material still in viscous form is immediately removed under pressure by a transverse scraper. The process of hunting under pressure should not be confused with a simple scraping. During this operation, the pressure probably causes a slight expulsion of filler material downstream of the scraper through the recesses of the surface to be overmolded, and the filler material relaxes when it passes from the viscous and compressed state to the solid state. This results in an excess thickness of filler polyethylene in the hollow surface areas requiring repair. This effect would not be obtained with a traditional scraping.

Preferably, the transverse scraper consists of a blade brought substantially to the temperature of the display shoe; the scraper is integral with said display shoe.

The blade advantageously consists of a substantially straight transverse lower edge separating an anterior face and a posterior face.

During the sweeping movement, the transverse scraper can advantageously be held in sliding contact with the lower edges of the ski, the thermoplastic filler material ensuring sufficient lubrication to promote sliding between the scraper and the ski edges without excessive wear of the scraper and edges.

The overmolding head according to the present invention substantially takes up the structure of the devices described in patent FR-A-2 391 054, and further comprises, downstream of the distribution zone, a transverse scraper shaped to scrape the filler material still in liquid form on the ski sole.

The transverse scraper is preferably a blade made of heat conducting material and subjected to the action of heating means bringing it to a temperature at least equal to the softening temperature of the filler material.

It is advantageously possible to use a blade in the form of a steel bar of rectangular section, integral with the display shoe, and thus driven in translation and heated by the display shoe. One of the edges of the steel bar forms the sharp lower edge which protrudes below the distribution and display surface of the shoe.

It has been found that the result can be markedly improved, on the one hand by appreciably increasing the speed of translation, but also by simultaneously adjusting several of the shape parameters of the heating and display pad appropriately.

For this, according to an advantageous embodiment, the projecting edge of the scraper protrudes below the distribution and spreading surface of the skate at a height of between two and four tenths of a millimeter. Also, the front face of the scraper forms, with the distribution and spreading surface of the shoe, an angle between one hundred and five and one hundred and thirty five degrees, advantageously one hundred and twenty degrees approximately.

Tests have shown that sufficient pressure must be applied by the pad on the thermoplastic filler material in the area between the pad and the sole to be molded. To apply such pressure, which must be controlled, it is advantageous to associate the skate with a fixed chassis structure comprising means for supporting the skate and the ski to be overmolded, means for driving the skate and the ski in relative longitudinal translation, and means for holding the pad against a ski sole against a determined force during the longitudinal translational movement. The bearing force applied to the shoe is advantageously between two hundred and five hundred Newton, the translation speed being advantageously between 3 and 4 meters per minute.

According to an advantageous embodiment, the overmolding head is mounted oscillating on a transverse axis fixed to a pressing arm connected to the frame, while the ski support is mobile and driven in longitudinal translation. The ski support comprises a movable and removable straddle comprising a rectilinear beam associated with wedges and with means for holding the ski. The external surface of the rectilinear beam forms a bearing surface, opposite to the surface to be machined of the ski, on which rolls a driving roller with transverse rotation shaft urged by a motor and mounted on the frame. Pressing means produce an appropriate pressure to keep the overmolding head in abutment against the ski. The rotation shaft of the roller is advantageously arranged along the mean vertical transverse plane of the overmolding head. Thus, the roller and the compression force of the molding head are opposite with respect to the assembly formed by the ski and the straddle, and located in the same vertical transverse plane.

Preferably, the straddle bearing surface includes notches cooperating with corresponding notches formed on the surface of the driving roller.

• - la figure 1 représente une vue schématique en perspective d'une tête de surmoulage selon la présente invention, en fonctionnement sur une semelle de ski à surmouler ;
• - la figure 2 est une vue de côté en coupe longitudinale d'une tête de surmoulage selon la présente invention ;
• - la figure 3 est une vue de face, en coupe partielle, d'un dispositif de surmoulage selon la présente invention comprenant une tête de surmoulage et des moyens de maintien du ski ;
• - la figure 4 est une coupe longitudinale d'un enjambeur support de ski selon la présente invention ;
• - la figure 5 est une coupe transversale selon le plan C-C de la figure 4 ;
• - la figure 6 représente, en vue de face, le détail des moyens de liaison entre l'enjambeur et la spatule d'un ski ;
• - la figure 7 représente ces mêmes moyens de liaison en vue en bout ; et
• - la figure 8 représente, en vue de face, le détail de réalisation des moyens de liaison entre le talon de ski et l'enjambeur.

Other objects, characteristics and advantages of the present invention will emerge from the following description of a particular embodiment, given in relation to the attached figures, among which:

• - Figure 1 shows a schematic perspective view of a molding head according to the present invention, in operation on a ski sole to be molded;
• - Figure 2 is a side view in longitudinal section of an overmolding head according to the present invention;
• - Figure 3 is a front view, in partial section, of an overmolding device according to the present invention comprising an overmolding head and means for holding the ski;
• - Figure 4 is a longitudinal section of a ski support straddle according to the present invention;
• - Figure 5 is a cross section along the plane CC of Figure 4;
• - Figure 6 shows, in front view, the detail of the connecting means between the straddle and the tip of a ski;
• - Figure 7 shows these same connecting means in end view; and
• - Figure 8 shows, in front view, the detail of the connection means between the ski heel and the straddle.

The overmolding head according to the present invention, shown diagrammatically in FIGS. 1 and 2, essentially comprises a heating body, generally referenced 1, made of thermally conductive metal, in which are housed heating cartridges such as cartridges 2 and 3 containing a distribution of electrical resistances. The heating cartridges 2 and 3 are distributed in the heating body to ensure an appropriate distribution of temperature in the heating body. The central part of the heating body, during operation, is brought to a temperature between 320 and 340 ° C, advantageously about 330 ° C. The heating body 1 is traversed right through by extrusion conduits such as the conduit 4. One can for example provide two extrusion conduits 4 and 5 whose upper portions are substantially parallel. The upper end of the extrusion conduits is shaped to receive the filler material in solid form. For example, the filler material may be in the form of a polyethylene wire, or two polyethylene wires generally referenced 6 and 7, coming from storage coils not shown in the figures. Mechanical drive means, not shown in the figures, such as knobs driven by a motor and between which the solid filler material engages, force the thermoplastic filler material inside the extrusion pipes 4 and 5 in the direction of the lower end of the extrusion pipes.

According to a first embodiment, the extrusion conduits 4 and 5 are each separated into two lower branches 41, 42, 51, 52 respectively, which open, on the lower face 8 of the heating body, in a transverse distribution groove 9 The orifices of the four lower branches 41, 42, 51 and 52 occupy positions regularly distributed over the length of the groove and cut said length into four substantially equal sections.

According to an advantageous embodiment, it is possible to omit the external branches 42 and 52 and to keep only the internal branches 41 and 51 oblique and converging, opening into the transverse groove 9 according to two orifices distant by approximately 15 millimeters. The filler material is thus less quickly driven to the edges of the surface to be overmolded. The underside 8 of the heating body 1 is flat. In the lower portion, the heating body 1 flares in a first longitudinal direction relative to the transverse distribution groove 9 to form a preheating shoe. The flat underside 8 extends under the preheating shoe, and constitutes an anterior zone 10 or preheating surface of the ski sole. The lower face portion 8 opposite the preheating shoe relative to the transverse groove 9 forms the display zone 25.

The transverse distribution groove 9 is closed at its two ends, to prevent too rapid creep of filler material at the ends. Its length is between 90 and 100 mm approximately, its width between 4 and 7 mm approximately, its depth between 2 and 3.5 mm approximately. Advantageously, it is possible to choose a length of approximately 95 mm, a width of approximately 6 mm, a depth of approximately 3 mm.

The heating body 1, as well as the means for mechanically driving the solid material, are contained in a box not shown in the figures, ensuring protection and thermal insulation of the heating body, only the underside 8 of the body. heater being visible and accessible.

A temperature sensor 11 is housed in the heating body 1, and is associated with temperature regulation means for maintain, during operation, the temperature of the heating body 1 at a determined value suitable for melting the thermoplastic filler material in the extrusion conduits 4 and 5.

The overmolding head is intended to be placed in abutment on a ski sole 12, with its lower face 8 substantially parallel to the sole surface, and to be moved longitudinally on said sole in a preferred direction of movement represented by the arrow 13 , that is to say the direction of movement in the direction of the glow shoe. An advantageous arrangement consists of mechanical means allowing the ski to move in the opposite direction illustrated by arrow 130, the overmolding head remaining fixed in the longitudinal position, and being possibly articulated and urged by means of support and support producing the support force F. Thus, relative to the transverse distribution groove 9, the upstream zone of the heating body 1 comprising the front zone 10 and the downstream zone of the heating body 1 or display zone 25 are defined. .

Downstream of the display area 25, the heating body 1 comprises a transverse scraper 14 shaped to scrape the filler material still in viscous form on the ski sole 12. In the embodiment shown, the scraper 14 is a steel bar of rectangular section, inclined by about thirty degrees relative to the perpendicular to the lower face 8 of the heating body 1, and fixed to the rear face of the heating body by fixing screws 15. By due to its inclination, the bar has a sharp transverse lower edge 16 formed by an anterior face 17 of scraper and a rear face 24 of scraper. The lower edge 16 of the bar forming the scraper 14 is slightly protruding below the lower face 8 of the heating body 1. The protruding value D is advantageously between two and four tenths of a millimeter. By the fact of the inclination of the bar forming the scraper 14, the front face 17 of the bar forms, with the lower face 8 of the heating body 1, an angle A of between one hundred and five and one hundred and thirty five degrees and forms with the surface sole to be molded at an angle B between 45 ° and 75 °. One can advantageously choose an angle A of one hundred and twenty degrees, and therefore an angle B of 60 °. Such an inclination produces a wedge effect and a flushing effect which promote the penetration of the thermoplastic material into the slots and other hollow parts of the sole to be molded. An angle B greater than approximately 75 ° produces grazing phenomena. An angle B less than 45 ° reduces the hunting effect too much, and results in a simple crushing effect, the result of which is less favorable. Excellent results have been obtained for an angle B of between 55 ° and 65 °, and therefore for an angle A of between 115 ° and 125 °.

In the embodiment shown, the scraper 14 is formed by a removable and interchangeable blade, which can also be adjusted to modify at will the protrusion D of the lower edge 16 below the lower face 8 of the heating body 1. It will however be possible, without departing from the scope of the present invention, to provide a scraper 14 permanently fixed to the heating body 1, without the possibility of adjustment.

The operation of the device of the present invention, for obtaining a selective overmolding limited to degraded surface areas, is improved by the application of a sufficient force F on the heating body 1 in the direction of the ski sole. , oriented substantially vertically from the display area 25, as shown by arrow 18. For a device intended to cover the total width of the ski, the force F is generally between 200 and 500 Newton. Such a force F, advantageously of the order of 200 to 250 Newton, can be produced by hand by the operator. Preferably, the force F can be produced by mechanical means, making it possible to maintain and control the application and the direction of this force, and to adjust it to an adequate value to obtain a regular result. The overmolding head is, for this, associated with support means making it possible to support on the one hand the overmolding head and on the other hand the ski to be overmolded. Mechanical means make it possible to drive the overmolding head and the ski 12 in relative longitudinal translation, at a speed V advantageously between 3 and 4 meters per minute, and mechanical means make it possible to maintain the body in support according to the force F determined. heating 1 against the ski sole according to its underside 8, as shown in FIG. 1. The mechanical drive means of the filler material ensure a continuous and regular supply of polyethylene, at a rate sufficient to fill, with a slight excess, the hollow areas of the ski sole 12.

For a device intended to cover a portion of the width of the ski, for example half width, force F can be reduced in proportion. Such a device can then more easily be manipulated and actuated by hand, without requiring mechanical means for producing the force F. A driving roller can however assist the operator to produce the regular advance of the device on the sole of ski in the direction of arrow 13.

During operation, the heating body 1 is kept in abutment on the ski sole 12, applying the necessary force F and said heating body 1 and the ski are driven in relative translation, for example skiing in the direction represented by the arrow 130 relative to a fixed heating body 1. The heating body 1 is maintained at a suitable temperature for melting the thermoplastic material 6, 7 introduced into the extrusion conduits 4 and 5, the filler material being gradually softened in the heating body and conveyed in liquid form under the heating body, and distributed in the transverse distribution groove 9. The flat bottom face 8 of the heating body 1 ensures on the one hand the preheating of the sole part 12 located upstream under the anterior zone 10, then the crushing and spreading of the filler material by the spreading zone 25. At the end of the spreading zone 25, the thermoplastic filler material, still in viscous form, is removed under pressure by the transverse scraper 14. During operation, the scraper 14 is in sliding support on the lower edges 22 and 23 of the ski. Good results are obtained by using a lower face 8 of the heating body 1, the total length of which is between approximately 90 and 110 mm, so that the preheating of the sole to be molded is sufficient.

The relative position of the underside 8 of the heating body 1 and the sole 12 of the ski must advantageously be kept constant during the molding operation. Preferably, the lower face 8 must be slightly detached from the sole to be molded 12 from the ski, so that the only contact with the sole is ensured by the scraper. For this, an anterior roller 26 is provided, mounted idly on a transverse axis 27 integral with the not shown fixing means of the heating body 1, such that the anterior end 28 of the lower face 8 is separated from the ski sole 12 by a space E advantageously between 1 and 3 mm, for example 2 mm. Space E prevents the surface to be molded from coming into contact with parts of the lower heating face 8, as a function of the camber of the ski, which, by reducing the force F, would disturb the effectiveness of the scraper 14.

In the case of a device actuated by hand, the roller 26 can advantageously be motorized.

It can be seen that, by using the method and the device according to the invention, a selective overmolding is carried out by adding thermoplastic material in the hollow zones of the sole 12 to be overmolded, zones which have been shown under the references 19 and 20 on the Figure 1, while the flat areas such as the area 21 of the sole 12 retain practically no molding material. In the hollow zones 19 and 20, after cooling, the thermoplastic filler material forms a slight excess thickness above the generally flat surface of the sole 12. It is then enough, by a light scraping, sanding or subsequent grinding, to reduce the overthickness and a regular sole surface is thus obtained in which the thermoplastic filler material is limited to only the hollow areas requiring repair.

Good results have been obtained in particular with a filler polyethylene sold commercially under the brand LAFIX. Other materials can however be used, and lead to satisfactory results, that is to say a selective overmolding in excess thickness in the hollow areas of the soles.

It is also noted, using the method of the present invention, that the flat areas 21 of the sole 12, made of a very high molecular weight polyethylene, are not degraded by the heat provided by the heating body 1 or the overmolding material during their passage, and retain their superior sliding properties. Indeed, the method of the invention avoids superimposing a hot film of filler material on the flat areas 21 of the sole 12, a film which heats the sole by conduction and makes it lose the properties specific to sintered polyethylene.

In Figure 3, there is shown a general view of an advantageous embodiment of the device according to the invention. The device comprises a fixed frame 100 carrying the overmolding head. Drive means are provided for driving the ski 12 in longitudinal translation.

The heating body 1 is mounted oscillating on the transverse axis 101 of a support arm 104 pivoting on an axis 105 fixed to the frame 100, while the ski 12 is driven in translation by support means 30 and 102 in a preferential direction represented by the arrow 130. The pivoting movements are represented by the double arrow 106 and make it possible to move the molding head 1 closer and further away from a driving roller. In the description and the claims, the direction of relative movement 130 of the ski 12 defines the longitudinal direction; the transverse direction is a horizontal perpendicular to the longitudinal direction. The support means comprise a straddle 30, integral with the ski 12, and biased by a driving roller 102 mounted in rotation according to a motorized transverse shaft 103. The rotation shaft 103 of the driving roller 102 is disposed substantially along a vertical transverse plane II passing through the middle of the overmolding head 1. The assembly formed by the straddle member 30 and the ski 12 is inserted in translation between the roller driver 102 and the overmolding head 1. The overmolding head 1 is supported on the sliding surface 61 of the ski, while the driving roller 102 is supported on the flat or notched outer face 29 of the straddle 30.

Maintaining the ski 12 and the straddle 30 during their passage between the driving roller 102 and the overmolding head 1 can be supplemented by an upstream support roller 114 and a downstream support roller 115, disposed respectively upstream and downstream of the overmolding head as shown in the figure, and journalling respectively on horizontal transverse axes carried by the frame 100. The support rollers 114 and 115 are arranged in a substantially horizontal plane passing through the contact generator of the driving roller 102.

The driving roller 102 is rotated, in the direction shown by the arrow 107, by a motor not shown in the figures. The pressing arm 104 is biased by a spring or a jack such as a gas jack, not shown in the figures, applying the overmolding head 1 against the sliding face 61 of the ski mounted on the straddle 30 in the direction of the roller. coach 102.

In the embodiment shown in Figures 3 to 8, the straddle 30 is shaped to compensate for natural irregularities in the shape of the ski 12. The straddle 30 must adapt to the shape of traditional skis, which have a body of ski 60 elongated and flattened, limited by the sliding face 61, by the upper face 62 and by two side edges. The front end of the body 60 is bent upwards to form a spatula 63, and its rear end is slightly bent upwards to form a heel 64. The body 60 has a variable thickness depending on the longitudinal position considered along of the ski, the thickness being greater in the central part of the body 60 than in the vicinity of the ends of the ski. The upper face 62 receives the bindings 65 and 66 allowing the adaptation and the maintenance of a ski boot, when using the ski on snow. The body 60 is arched, so that, when the ski is placed on a plane along its lower sliding face 61, it rests along two lines located in the vicinity of the ends of the ski, the central part of the sliding face 61 being raised with respect to the support plane.

To adapt to these particular shapes, the straddle member 30 comprises a rectilinear longitudinal beam 34 with a general U-shaped section, its outer face 35 receiving a notched tread 36. The beam 34 carries sliding blocks such as wedge 37. One can for example provide a shim 37 which will be disposed in the vicinity of the front attachment 65, a shim 38 disposed in front of the shim 37, two shims 39 and 40 in the vicinity of the rear end of the beam 34. The shims can be adjusted in longitudinal position along the beam 34 by sliding, for example according to a structure schematically shown in Figure 5 in cross section. The shims 37, 38, 39 and 40 have adjustable heights, and chosen in such a way that, when the ski is in the overmolding position as shown in FIG. 3, the shims compensate for the camber of the ski and tend to make its face sliding 61 to be overmolded substantially planar and parallel to the outer surface 35 of the beam 34.

Various means can be used to secure the ski 12 and the straddle 30 relative to each other. In the embodiment shown in FIGS. 4 to 7, the attachment is provided by means 43 for attaching the tip 63, means 44 for attaching the heel 64, and means for attaching an intermediate part of the body of ski.

The attachment of the intermediate part of the ski body can advantageously be ensured by the intermediate wedge 37, shaped to come under the wings of the front binding 65 of the ski. Such embedding prevents that one can separate the ski 12 and the straddle member 30 by a simple translational movement perpendicular to the sliding surface of the ski. It is thus possible to manipulate the ski-straddle assembly by the single ski, without the risk of seeing the ski unhook from the straddle.

The attachment means 43 of the spatula comprises a transverse retaining spacer 46 connecting two lateral support flanges 45 substantially shaped to the profile of the spatula 63 and provided with pads 48 and 49. The pads and the flanges are integral with the beam 34 and arranged, as shown in the figures, in such a way that the tip 63 can be engaged between the flanges 45 and the retaining spacer 46 and that, when the tip is thus engaged and the ski heel is lowered as the represents the arrow 47 of FIG. 6, the spatula 63 is wedged by pressing on the upper face of the pads 48 and 49 and immobilized under the lower face of the retaining spacer 46. The support flanges 45 are advantageously provided with flexible pads 48 and 49 forming a flexible and elastic support for the corresponding face of the spatula 63.

The means 44 for securing the heel 64, better represented in FIG. 8, comprises an enveloping rear stop 53, comprising a projecting part 54 under which a short length of the heel 64 engages. The rear stop 53 is rounded to form a progressive routing ramp of the overmolding head on the ski. The curvature of this stop 53 must be adapted so that the overmoulding shoe 1 alone is in support, without the scraper blade coming to bear on this stop. Such support could indeed damage the blade. A thin sheet 55 is superimposed on the rounded shape of the rear stop 53. The sheet 55 has a double role: it firstly wipes the initial flow of polyethylene leaving the overmolding head; this initial flow generally comprises relatively carbonized polyethylene which is unsuitable for overmolding, the material of which it is made having parked in standby in the heating body and having been overheated during cycle interruptions. The thin sheet 55, for example of copper, also allows good connection of the molding sole with different shapes of ski heels, favoring by deforming slightly a clean start of the molding in the heel. The rear stop 53 is movable longitudinally as shown by the double arrow 56, for the installation of the device: when the ski 12 is in place, the heel 64 being in position, the stop 53 is advanced so that its projection 54 partially covers the heel 64. The intermediate wedge 40, adjustable in longitudinal position and adjustable in height, makes it possible, in cooperation with the stop posterior 53, good blocking of the heel 64.

The ski 12 and the straddle member 30 thus form a one-piece assembly, the ski being pressed against the straddle member during the introduction between the driving roller 102 and the overmolding head 1, heel forward, in the longitudinal direction represented by the arrow 130. The rotation of the roller 102, in the direction represented by the arrow 107, drives the assembly formed by the ski 12 and the straddle member 30 at an appropriate regular translation speed, the sliding surface 61 of the ski being supported on the heating and spreading pad, the driving roller 102 being in abutment on the outer face 29 of the coach. The driving roller 102 can advantageously be provided, at its periphery, with transverse notches complementary to the notches of the tread 36. This avoids slipping between the driving roller 102 and the straddle 30, so that the straddle is driven at regular speed.

The straddle device according to the invention also has the advantage of facilitating the subsequent treatment of the ski after overmolding. In fact, the ski is generally routed, after overmolding, to an abrasive belt or stone sander. The most modern sanders have an automatic drive. The straddle is adapted to also pass in such coaches. As a result, it is no longer necessary to move the ski from one workstation to another, and one can provide a device comprising a molding head followed by a sander, the two operations being carried out one after the other by a single translation of the straddle and the ski.

According to an advantageous embodiment, the device of the invention further comprises means for adjusting the speed of the motor driving the solid filler material for its introduction into the heating body 1, associated with means for adjusting the the pressing force F. The adjustment can be simultaneous by a single control member. These means make it possible, by increasing the flow rate of the filler material, for example by approximately 50%, and simultaneously reducing the bearing force F, for example by setting it at around 150 Newton, to significantly reduce the hunting effect of the scraper 14 and to deposit more filler material on the ski. This adjustment can be useful when the heel and the tip of the ski are concave, the complete overmolding then making it possible to reload this concavity and restore a regulated sole.

The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims (22)

1 - Method for overmolding by scanning the ski sole (12), in which:
- a thermoplastic filler material (6, 7) is continuously conveyed in solid form in a heating body shaped as a display shoe (1), the filler material (6, 7) being progressively softened in the body (1) and conveyed in liquid form and distributed in a transverse groove under the pad, to then be crushed and spread on the ski sole (12), the display pad being moved relative to the ski surface at a speed scanning V,
characterized in that:
- At the end of the display zone (25), the thermoplastic filler material still in liquid or at least viscous form is removed under pressure by a transverse scraper (14). 2 - Method according to claim 1, characterized in that the transverse scraper (14) comprises a blade brought to the temperature of the display shoe (1) and integral with the display shoe (1). 3 - Method according to one of claims 1 or 2, characterized in that, during the sweeping movement, the transverse scraper (14) is in sliding support on the edges (22, 23) of the ski. 4 - Method according to any one of claims 1 to 3, characterized in that the scraper (14) comprises a sharp edge (16) substantially straight transverse separating an anterior face of scraper (17) and a rear face of scraper (24 ), the front face of the scraper (17) being kept inclined relative to the ski sole to form a wedge whose opening angle B is kept substantially constant and between approximately 75 ° and 45 °, so as to avoid grazing phenomena and produce a good hunting effect. 5 - Method according to claim 4, characterized in that:
a bearing force F determined on the display shoe (1) is applied in the direction of the ski sole (12) and substantially vertical to the display area (25),
- the sharp edge (16) of the scraper protrudes below the surface of the display shoe (1) according to an overhang D of between 2 and 4 tenths of a millimeter,
- the speed V is between 3 and 4 meters per minute approximately,
- the pressing force F is between 200 and 500 Newton. 6 - Method according to claim 5, characterized in that the angle B is between 65 and 55 °. 7 - Method according to one of claims 5 or 6, characterized in that the support force F is between 200 and 250 Newton. 8 - device for overmolding by scanning the ski sole for implementing the method according to claim 1, comprising means for supplying a thermoplastic filler material, a heating and spreading pad (1) shaped to receive the filler material in solid form (6, 7), for gradually heating and softening it, for bringing it in liquid form under a distribution and spreading structure (1, 9, 25) intended to be pressed against the ski sole (12) and driven in longitudinal relative translation on said ski sole in a preferred direction of propagation (13), the shoe (1) comprising: - a lower distribution surface (8), generally planar, comprising a anterior zone (10) for preheating the ski sole, followed by a transverse groove (9) for distribution into which the molten filler material is brought, itself followed by a display zone (25),
characterized in that it comprises:
- Downstream of the distribution (9) and display (25) zone, a transverse scraper (14) for scraping the filler material still in liquid or at least viscous form on the ski sole (12). 9 - Device according to claim 8, characterized in that the transverse scraper (14) is subjected to the action of heating means bringing it to a temperature at least equal to the softening temperature of the filler material. 10 - Device according to one of claims 8 or 9, characterized in that the scraper comprises a lower edge (16) substantially transverse sharp transverse projecting below the distribution surface (8) and spreading of the pad and separating an anterior face (17) of scraper and a rear face (24) of scraper, the scraper being integral with the display shoe. 11 - Device according to claim 10, characterized in that:
- the lower edge (16) protrudes by a height D of between two and four tenths of a millimeter,
- The front face (17) of scraper forms, with the distribution surface (8) and spreading of the shoe, an angle A comprised between one hundred five and one hundred thirty five degrees, preferably comprised between one hundred fifteen and one hundred twenty five degrees about. 12 - Device according to any one of claims 8 to 11, characterized in that:
the display shoe (1) is heated by electrical resistors distributed in its central part giving said central part a temperature between 320 and 340 ° C,
- the distribution surface (8) has a length of between 90 and 110 mm. 13 - Device according to any one of claims 8 to 12, characterized in that the transverse groove (9) for distribution is closed at its two ends, and has a length between 90 and 100 mm, a width between 4 and 7 mm, a depth between 2 and 3.5 mm. 14 - Device according to claim 13, characterized in that the transverse groove (9) has substantially the dimensions: length 95 mm, width 6 mm, depth 3 mm. 15 - Device according to any one of claims 8 to 14, characterized in that it comprises a roller (26) front mounted on a transverse axis (27) integral with the heating body (1) and arranged to maintain a space E constant between the anterior end (28) of the lower face (8) and the surface (12) to be overmolded. 16 - Device according to any one of claims 8 to 15, characterized in that the display shoe (1) is associated with a fixed frame structure (100) comprising means for supporting the display shoe (1) and the ski (12) to be overmolded, means (102, 30) for driving in relative longitudinal translation the display shoe (1) and the ski (12), and means (104) for keeping in support according to a force determined F the display shoe (1) against the ski sole (12) during the longitudinal translation movement, the pressing force F being between two hundred and five hundred Newton, the translation speed being between 3 and 4 meters per minute. 17 - Device according to claim 16, characterized in that:
- the ski (12) is associated with a ski support (30),
the ski support (30) is movable and driven in longitudinal translation on the frame (100),
the ski support (30) comprises a removable straddle comprising a rectilinear beam (34) associated with wedges (37, 38, 39, 40) and means of fixing (43, 44) to the ski,
the rectilinear beam (34) forms a bearing surface (35), opposite the ski surface to be machined (61), and on which rolls a driving roller (102) urged by a motor,
- pressing means (104) produce an appropriate pressure of the overmolding head (1) to maintain the ski (12) on the beam (34) in abutment on the driving roller (102). 18 - Device according to claim 17, characterized in that the wedges (37, 38, 39, 40) have different lengths and chosen so that they compensate for the camber of the ski and tend to make the sliding surface (61 ) of the ski during its passage in the device. 19 - Device according to any one of claims 17 or 18, characterized in that the bearing surface (35) of the straddle has notches (36) cooperating with the corresponding notched outer surface of the driving roller (102). 20 - Device according to any one of claims 17 to 19, characterized in that the pressing means are springs or gas spring producing a force of about 250 Newton. 21 - Device according to any one of claims 17 to 20, characterized in that the straddle includes a device (43) for locking the tip (63), a device (44) for locking the heel (64), and means (37) for locking the ski in an intermediate zone. 22 - Device according to any one of claims 16 to 21, characterized in that it comprises:
means for adjusting the speed of the means for supplying solid filler material, allowing a speed increase of approximately 50%,
- means for adjusting the pressing force F, allowing a reduction in the force up to approximately 150 Newton, to allow to achieve at will, with the same device, a selective overmolding in degraded areas and a complete overmolding in the concave ski sole zones (12).

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