EP0504073A1 - Ski dressing apparatus - Google Patents

Abstract

The apparatus according to the invention comprises an abrasive belt (6) tensioned between a support drum (3) and a return drum (5), the unit being driven in rotation by a motor (7) placed between the support drum (3) and the return drum (5) and between the abrasive belt bearing surfaces (61, 62) linking the drums. The support drum (3) is formed by at least two sections of differing hardness, namely a section with a rigid peripheral surface for grinding (sanding) with stone, and a section with an elastic peripheral surface for a rough grinding (sanding) or a surface finish grinding (sanding). A driving drum is optionally placed above the support drum (3) for motorised driving of the ski. <IMAGE>

Description

The present invention relates to devices for sanding skis, in particular their lower sliding surface.

Such devices are generally used for the repair of ski soles. The sanding operation can take place after a reloading operation by overmolding the sliding sole.

The sanding devices currently used for skis are generally abrasive belt devices, comprising a frame resting on the ground and supporting the functional parts of the device, a support drum mounted to rotate about a first horizontal axis and forming a zone of support accessible to receive the ski surface to be sanded, a return drum rotatably mounted along a second horizontal axis offset from the first axis, and an abrasive strip stretched between the support drum and the return drum. Tensioning means urge at least one of the drums away from the other to tension the abrasive belt. Motor means are used to rotate the support drum and the abrasive belt. Water circulation means project jets of water onto the zone of abrasive band surrounding the support drum, and collect the water which flows on the abrasive band after it has passed through the machining zone.

The abrasive strip is generally of a width sufficient to sand an alpine ski, that is to say of a width of between 10 and 20 cm approximately.

A similar technique is described in documents DE-A-2 502 718 and US-A-2 827 935 for the machining of panels: the panels pass between an upper drive drum and a portion of abrasive band surrounding a lower drum support.

In document US-A-4,137,673, an abrasive strip is stretched between two rollers, and forms a support ply bearing on a deformable support. The ski is machined by the support ply and is driven by driving rollers.

The devices usually used, however, do not have a sufficient width so that the entire width of a snowboard can be sanded during a single pass on the strip.

On the other hand, it appears that the sanding obtained does not have an always sufficient surface quality both in terms of flatness and surface roughness. For this, for example in document FR-A-2 614 819, special sanding devices have already been proposed consisting of a grinding wheel or a rigid drum. Such sanding by a grinding wheel is generally referred to as "stone sanding", ensuring the planning of the lower surface of the ski. It is then necessary to combine, in several passes on different machines, one or more sanding with an abrasive belt and at least one "sanding with stone". Each pass requires belt speed, translation speed of the ski on the device, and ski pressure on the abrasive belt or the grinding wheel. The results depend significantly on the skill of the user, and lack consistency. This solution is therefore not technically satisfactory. In addition, the use of several machines significantly increases production costs, requires a lot of space, complicates handling, and we find that such complexity becomes prohibitive for sports shops and ski equipment rental companies, which most often tend to settle for an abrasive belt device.

The object of the present invention is in particular to avoid the drawbacks of known apparatuses, by proposing a new structure of apparatus for sanding skis in which the same apparatus makes it possible to successively carry out rough sanding operations, "sanding with stone "or planning or flattening, finishing sanding. These various operations are made possible on the same device by means allowing their compatibility.

According to another aspect of the invention, the different working possibilities of the device according to the invention are obtained without significant increase in the volume or the floor area occupied by the device. On the contrary, the invention defines a new machine architecture making it possible to significantly reduce its size, and in particular its footprint.

Such an architecture also makes it possible to adapt on the same device, without appreciable increase in price and size, means carrying out sanding with falling edges: according to such sanding, the ski edges undergo a preferential removal of material so that their surface is, at the end of machining, slightly set back from the polyethylene surface constituting the central surface of the ski sole.

According to another aspect of the invention, it is sought to facilitate the management of the functional parts of the machine, to avoid the user having to define and execute long and tedious adjustments depending on the type of material to be machined and the machining step in progress. In particular, we note that different settings must be provided depending on whether it is an alpine ski, a monoski, a snowboard, and depending on whether it is a machining of '' roughing, planning or flat machining, finishing machining. The user simply has to indicate the type of product and the type of step, the settings then being carried out automatically.

• un bâti reposant sur le sol et supportant les organes fonctionnels,
• un tambour d'appui, monté rotatif selon un premier axe horizontal, et formant zone d'appui accessible pour recevoir la surface de ski à poncer,
• un tambour de retour, monté rotatif selon un second axe horizontal décalé par rapport au premier axe,
• une bande abrasive tendue entre le tambour d'appui et le tambour de retour,
• des moyens tendeurs pour solliciter l'un au moins des tambours à l'écart de l'autre et tendre la bande abrasive,
• des moyens moteurs pour entraîner en rotation le tambour d'appui et la bande abrasive,
• des moyens de circulation d'eau pour projeter de l'eau sur la zone de bande abrasive entourant le tambour d'appui et pour recueillir l'eau coulant sur la bande abrasive ;
  selon l'invention, les aménagements sont les suivants :
• le tambour d'appui comprend au moins un premier et un second tronçons longitudinaux successifs présentant chacun une longueur supérieure à la largeur d'un ski alpin, et présentant des duretés superficielles différentes, à savoir un premier tronçon à surface élastique ayant une zone périphérique constituée d'une matière élastique, telle que caoutchouc ou polyuréthane souple, et un second tronçon à surface rigide ayant une zone périphérique constituée d'une matière rigide telle que l'aluminium,
• la bande abrasive recouvre simultanément tous les tronçons successifs du tambour d'appui,
• les moyens moteurs sont agencés pour entraîner en rotation le tambour d'appui selon au moins deux vitesses de rotation différentes appropriées correspondant respectivement à une première étape d'ébauche ou de mise à plat dans laquelle la surface de ski est poncée à grande vitesse de défilement de bande, et une seconde étape de finition dans laquelle la surface de ski est poncée à faible vitesse de défilement de bande,
• le tambour de retour est associé à des moyens de centrage de bande abrasive, pour guider ladite bande abrasive et assurer son maintien au voisinage d'une position sensiblement centrée sur les tambours de retour et d'appui.

To achieve these and other objects, the apparatus for sanding skis according to the invention comprises the known traditional elements, namely:

• a frame resting on the ground and supporting the functional organs,
• a support drum, rotatably mounted along a first horizontal axis, and forming an accessible support area for receiving the ski surface to be sanded,
• a return drum, rotatably mounted along a second horizontal axis offset from the first axis,
• an abrasive strip stretched between the support drum and the return drum,
• tensioning means for urging at least one of the drums away from the other and tensioning the abrasive belt,
• motor means for rotating the support drum and the abrasive belt,
• water circulation means for spraying water onto the zone of abrasive band surrounding the support drum and for collecting the water flowing on the abrasive band;
  according to the invention, the arrangements are as follows:
• the support drum comprises at least first and second successive longitudinal sections each having a length greater than the width of an alpine ski, and having different surface hardnesses, namely a first section with elastic surface having a peripheral zone formed an elastic material, such as rubber or flexible polyurethane, and a second section with a rigid surface having a peripheral zone made up of a rigid material such as aluminum,
• the abrasive belt covers all successive sections simultaneously the support drum,
• the motor means are arranged to rotate the support drum according to at least two different suitable rotational speeds corresponding respectively to a first roughing or flattening step in which the ski surface is sanded at high speed of travel band, and a second finishing step in which the ski surface is sanded at low band running speed,
• the return drum is associated with abrasive belt centering means, for guiding said abrasive belt and ensuring its maintenance in the vicinity of a position substantially centered on the return and support drums.

Preferably, to obtain good regularity of the result, the apparatus further comprises a driving drum, mounted to rotate about a third horizontal axis, movable between a retracted position in which it is away from the support drum to allow the introduction of the end of a ski, and a drive position in which it is brought closer to the support drum and urged in its direction by support means for pressing a ski and keeping it in abutment against the strip abrasive, the driving drum being biased in rotation by a driving motor.

According to a preferred embodiment, the support drum comprises three successive sections, namely a first end section with elastic surface, a second central section with rigid surface, and a third end section with elastic surface. The total length of the support drum, and the corresponding useful length of the abrasive belt, are greater than the width of a snowboard. With such a structure, the user can sand either an alpine ski, a monoski or a snowboard on the same abrasive belt. The "sanding with stone" or finishing operations are carried out on the second central section with a rigid surface. The roughing and surface planning operations are carried out on the first extreme section or the third extreme section with elastic surface.

• comprend un tambour d'appui et un tambour de retour disposés selon deux axes situés sensiblement sur le même plan vertical,
• le tambour d'entraînement éventuellement prévu est également disposé selon un axe situé dans le même plan vertical,
• le moteur d'entraînement du tambour d'appui est logé entre les tambours d'appui et de retour, et entre les deux portées de bande abrasive reliant lesdits tambours.

To obtain a significant reduction in size, the device according to the invention:

• comprises a support drum and a return drum arranged along two axes situated substantially on the same vertical plane,
• the drive drum which may be provided is also arranged along an axis located in the same vertical plane,
• the drive motor for the support drum is housed between the support and return drums, and between the two surfaces of the abrasive belt connecting said drums.

According to an advantageous embodiment, the support drum comprises an additional section with a very elastic surface surrounded by a circular abrasive strip pressed over its entire periphery and having a width at least equal to that of a ski, the circular abrasive strip being of an aggressive type for the steel forming the ski edges and less aggressive for the polyethylene gliding sole, so that the device comprises a support drum zone allowing the edges to fall.

• un cycle d'ébauche de semelle de ski alpin, avec une vitesse de bande élevée, une vitesse d'entraînement de ski faible, une force d'appui moyenne ou faible,
• un cycle de finition de ski alpin, avec une vitesse de bande faible, une vitesse d'entraînement de ski élevée, une force d'appui faible,
• un cycle de planification de semelle de ski alpin, avec une vitesse de bande élevée, une vitesse d'entraînement de ski faible, une force d'appui élevée ou moyenne,
• un cycle d'ébauche de planche à neige, avec une vitesse de bande élevée, une vitesse d'entraînement de ski faible, une force d'appui élevée,
• un cycle de finition de planche à neige, avec une vitesse de bande faible, une vitesse d'entraînement de ski faible, une force d'appui élevée,
• un cycle de tombé des carres, avec une vitesse de bande élevée, une vitesse d'entraînement de ski faible, une force d'appui faible ou moyenne.

Ease of control is obtained by a control device comprising a control console mounted on the frame, the control console can advantageously be provided with a series of pedals articulated on the chassis and actuating a series of switches corresponding to several cycles of basic such as:

• an alpine ski sole roughing cycle, with a high band speed, a low ski drive speed, a medium or low bearing force,
• an alpine ski finishing cycle, with a low belt speed, a high ski drive speed, a low bearing force,
• an alpine ski sole planning cycle, with a high band speed, a low ski training speed, a high or medium bearing force,
• a snowboard roughing cycle, with a high belt speed, a low ski drive speed, a high bearing force,
• a snowboard finishing cycle, with a low band speed, a low ski drive speed, a high downforce,
• an edge drop cycle, with a high belt speed, a low ski drive speed, a low or medium pressing force.

• la figure 1 est une vue générale de côté en coupe d'un appareil selon la présente invention dans un premier mode de réalisation ;
• la figure 2 est une vue de côté d'un appareil selon un second mode de réalisation de l'invention, comportant un tambour d'entraînement ;
• la figure 3 illustre, en vue de côté, la structure générale d'un dispositif de centrage de bande abrasive selon un mode de réalisation possible ;
• la figure 4 est une vue de face du dispositif de centrage de bande abrasive selon la figure 3 ;
• la figure 5 est une coupe longitudinale d'un tambour d'appui selon un mode de réalisation de l'invention ;
• la figure 6 est une vue de face d'un appareil selon l'invention dans le mode de réalisation de la figure 2 ; et
• la figure 7 est une vue de face en coupe médiane de l'appareil selon la figure 6.

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

• Figure 1 is a general side view in section of an apparatus according to the present invention in a first embodiment;
• Figure 2 is a side view of an apparatus according to a second embodiment of the invention, comprising a drive drum;
• Figure 3 illustrates, in side view, the general structure of an abrasive belt centering device according to a possible embodiment;
• Figure 4 is a front view of the abrasive belt centering device according to Figure 3;
• Figure 5 is a longitudinal section of a support drum according to an embodiment of the invention;
• Figure 6 is a front view of an apparatus according to the invention in the embodiment of Figure 2; and
• FIG. 7 is a front view in median section of the apparatus according to FIG. 6.

FIG. 1 represents an apparatus according to the present invention in a simplified embodiment not comprising a driving drum. In this embodiment, as well as in those which will be described below, the apparatus comprises a frame 1 resting on the ground by feet 2 and supporting all of the functional organs of the apparatus.

The functional members include a support drum 3, mounted rotatably along a first horizontal axis I-I, and an upper peripheral zone of which forms a support zone outside the frame 1.

The functional members also include a return drum 5, rotatably mounted along a second horizontal axis II-II offset from the first axis I-I.

An abrasive strip 6 is passed around the support drum 3 and the return drum 5. Tensioning means, not shown in FIG. 1, urge the return drum 5 away from the support drum 3 to tension the abrasive strip 6. The upper portion 4 of abrasive strip 6 which covers the external support area of the support drum 3 is accessible by the user and is intended to receive the ski surface to be sanded. To allow sanding of snowboards, it is advantageous to provide that the total length of the drum support 3 and the width of the abrasive strip 6 are greater than the width of a snowboard.

A motor 7 is coupled to the support drum 3 by a transmission belt 8, and rotates the support drum 3 and the abrasive belt 6 in the preferred direction of rotation represented by the arrow 12.

Water spraying means make it possible to spray water onto the upper portion 4 of abrasive strip surrounding the support drum 3 and to collect the water flowing from the abrasive strip 6. For example, spray nozzles 9 are adapted to send water jets on the upper portion 4 on which the machining is carried out, and a tank 10 is provided in the lower part of the apparatus for collecting the water flowing from the abrasive strip 6, a filter 11 being adapted in the tank 10 to filter the water collected, and pump and pipe means making it possible to draw the water from the filtered part of the tank 10 to send it to the spray nozzles 9.

In this embodiment, the user must hold a ski in an inclined position and apply its sliding surface against the upper portion 4 of abrasive band 6 surrounding the support drum 3. The user scrolls the ski alternately in the two direction in its inclined direction as represented by the double arrow 130, for successively applying all the portions of the sliding surface of the ski against the abrasive strip. The quality of the surface condition obtained on the sliding surface of the ski depends on several factors, and in particular on the speed of rotation of the abrasive belt 6. For this, the user has a control console 14, provided several buttons allowing it to choose various rotation speeds of the motor 7.

To collect water spray and support the ski before it passes over the support drum 3, it is advantageous to provide an entry table 15, articulated on the frame 1 in order to be able to admit a folded position 151 shown in solid lines on Figure 1 and a deployed horizontal position 152 shown in phantom in the same figure. In the deployed position, the entry table 15 constitutes a horizontal support slightly below the level of the upper generator of the support drum 3 and extending in the entry area of the ski perpendicular to the axis II of the drum support 3. Cylinders 153 allow the maintenance of the input table 15 in the deployed position.

The relative arrangement of the various functional organs as shown in FIG. 1 leads to the production of a particularly compact device, having a reduced volume and a small footprint. According to this architecture, the support drum 3 is arranged along an axis II located substantially in the same vertical plane IV-IV as the axis II-II of the return drum 5, the support drum 3 being above the return drum 5. The motor 7 is housed between the support 3 and return 5 drums, between the two blanks 61 and 62 of abrasive band connecting said drums 3 and 5. The motor 7 is naturally protected from spraying water by the abrasive belt 6 itself, without requiring additional protective means. In the more complete embodiment shown diagrammatically in FIG. 2, the frame 1 carries the same functional organs arranged in the same way as in the embodiment of FIG. 1. For the sake of simplification, certain functional organs have not have been explicitly shown in Figure 2. Only have been shown the additional means constituted by a driving drum 17 and its actuating means, as well as an output table 16 which can optionally be added, articulated on the frame 1, and which can take a folded position 161 or a deployed position 162 in the ski exit area.

Thus, in this embodiment of Figure 2, the apparatus further comprises a driving drum 17, mounted rotatably along a third horizontal axis III-III. The driving drum 17 is disposed above the support drum 3, its axis III-III being located substantially in the same vertical plane IV-IV as the axes of the support drum 3 and the return drum 5. The drum driver 17 is movable between a raised position, shown in phantom in Figure 2, in which it is away from the support drum 3 to allow the introduction of the end of a ski between the two drums perpendicularly to their axes, and a drive position shown in solid lines in which it is brought closer to the support drum and urged in its direction by support means for pressing a ski and keeping it in abutment against the abrasive belt 6.

The driving drum 17 is coated with elastic coaxial rings 170 distributed over its length and responsible for promoting the adhesion of the skiing during his training. These elastic rings will more favorably have a hardness of between 40 and 60 Shore A.

The driving drum 17 is rotated around its axis III-III in the direction of arrow 120 by a driving motor, not shown in the figure. Thus, the driving drum 17 scrolls the ski horizontally in the direction represented by the arrow 13, against the rotation 12 of the abrasive belt 6. Advantageously, the driving motor is housed inside the driving drum 17 itself, and rotates the outer casing of the driving drum 17 relative to a central shaft 23. The driving motor is adapted to produce at least two distinct driving speeds, namely a slow speed of rotation and a fast rotation speed.

The driving drum 17 can also be retracted by pivoting around the transverse axis 180 of the carriage 18, to completely free the upper working portion 4 of the abrasive belt 6, this in order to carry out sanding work by manual drive. The retracted position is shown in phantom in Figure 2.

The central shaft 23 is fixedly mounted on a carriage 18 sliding on lateral vertical guides of the frame 1. As shown in FIGS. 2 and 6, the carriage 18 comprises two vertical uprights 19 and 20 whose upper ends are connected to two brackets 21 and 22 anteroposterior connected to each other by the fixed shaft 23. The uprights 19 and 20 are further connected to each other by an intermediate crosspiece 24, and they slide vertically in guides respective 25, 26, 27 and 28 lateral of the frame 1. The carriage 18, subjected to its own weight, rests freely by its crosspiece 24 on a cam 29 with horizontal axis of rotation urged by a carriage motor 30. By rotation of the motor carriage 30, the cam 29 performs a cycle during which it deploys by progressively pushing the carriage 18 upward to move the driving drum 17 away from the support drum 3, and then it retracts while letting the driving drum 17 towards the supporting drum 3. In the retracted position of the cam 29, the driving drum 17 is therefore biased by the own weight of the carriage 18 and of the driving drum 17 in the direction of the supporting drum 3. Advantageously, the weight of the assembly formed by the driving drum 17 and the carriage 18 corresponds to the maximum force required exercise to press the ski against the support drum 3 during the various sanding steps.

According to an advantageous embodiment shown in FIG. 2, the carriage motor 30 is controlled by at least one switch 300, actuable by a push-button, or more advantageously actuable by a pedal 310 articulated on the frame 1 along a transverse axis 320 and accessible by the user. The pedal 310 can be arranged on the upper face of the frame 1, to be easily actuated by pressing the sanding ski. The pedal 310 is preferably arranged to itself constitute a ski entry support, supporting the ski in a substantially horizontal position during its passage between the drums 3 and 17. Preferably, a pulse from the switch causes the realization of 'A complete cycle of the cam 29 according to an ascent and a descent of the driving drum 17, as well as the operation of the other organs of the device.

According to one embodiment, it is advantageously possible to provide an additional means for adjusting the bearing force of the driving drum 17. For example, a particularly simple embodiment consists in providing two different bearing forces, which can be chosen according to the steps desired machining. The first, most important bearing force is obtained by leaving the carriage 18 free in vertical translation, to apply the entire weight of the driving drum 17 and the carriage 18. A second, weaker bearing force is obtained by operating a gas spring 31 bearing under the cross member 24 of the carriage 18, to push up the cross member 24 and the carriage 18 carrying the driving drum 17. The thrust of the gas spring 31 can be suppressed by providing that the actuator rod 31 simply abuts against the underside of cross member 24 to push it up, and that a retractable stop 32 allows at will to retain actuator rod 31 in the low position or to authorize its pushing movement of the carriage. The retractable stop 32 is actuated by an electromagnet or electric strike or jack or any other means controlled by the user or by the switch 300. Thus, the carriage 18, the cam 29 and the jack 31 constitute suitable support means for produce at least two distinct support forces, a low support force during the intervention of the gas cylinder 31, a high support force when the cylinder 31 is blocked.

An intermediate support force can easily be obtained by adding a gas cylinder and an additional electromagnet to obtain a "medium" support force. It may indeed prove useful to have an additional adjustment of the pressing force, giving a "medium force", that is to reduce the aggressiveness of a new abrasive belt by passing from a high force to a medium force, or on the contrary to increase the efficiency of a used abrasive belt by passing from a weak force to a medium force. This additional adjustment can be obtained by at least one additional adjustment switch, actuating the additional gas spring.

According to the invention, the support drum 3 comprises at least a first and a second successive longitudinal sections, each having a length greater than the width of an alpine ski, and having different surface hardnesses, namely a first section with elastic surface having a peripheral zone made of elastic material, and a second rigid surface section having a peripheral zone made of rigid material.

For example, in the embodiment shown in longitudinal section in Figure 5, the support drum 3 comprises a core 33 of a rigid material such as aluminum. The core 33 itself constitutes the periphery of the central section 34 of the support drum 3. The peripheries of the two end sections 35 and 36 consist of a bandage made of an elastic material such as an elastomer. The set of peripheries of the central and peripheral sections 34 and 35 and 36 constitute a generally cylindrical outer surface of revolution of the support drum 3. Thus, in this embodiment, the support drum 3 comprises 3 successive sections, namely a first end section 35 with elastic peripheral surface, a second central section 34 with rigid peripheral surface, and a third end section 36 with elastic peripheral surface.

A simplified embodiment may consist in providing a support drum 3 having only two successive sections, for example a section 35 with elastic peripheral surface and a section 34 with rigid peripheral surface.

In all the embodiments, the abrasive belt 6 simultaneously covers all the successive sections of the support drum 3.

The fact of providing successive sections of different hardness makes it possible, with the same abrasive strip, to carry out machining of the ski gliding surface according to different conditions, in order to obtain suitable surface conditions and improved machining efficiencies. Each section of support drum 3 having a length at least equal to the width of an alpine ski, ie a length greater than approximately 10 cm, it is possible to provide several machining steps, each step using one of the sections of the same support drum 3. But the difficulty is that, when a ski is pressed on the part of the abrasive belt situated opposite a section of support drum 3 with elastic surface, for example the section 35, this support of the ski slightly deforms the peripheral surface of the support drum 3 and tends to unbalance the abrasive strip 6. This results in a tendency for the abrasive strip to move axially on the support drum 3 and possibly on the return drum 5. To avoid this, the present invention provides means for centering an abrasive belt, for guiding said belt and ensuring its maintenance in the vicinity of a position substantially centered on the return and support drums 5.

Various centering means can be used. There is for example shown in Figures 3 and 4 a possible embodiment of the centering means, adapted on the return drum 5. In this embodiment, the return drum 5 with free rotation along its axis II-II is mounted on a stirrup 37, the stirrup 37 being integral with a central sliding rod 38 slidably mounted on a guide 39 of the frame 1. The rod 38 can also freely pivot in the guide 39 along its longitudinal axis itself located in the vertical plane IV-IV of the apparatus, and perpendicular to the axis II-II. A centering cam 40, actuated by a centering motor 41, and associated with an opposite spring 42, controls the pivoting of the stirrup 37 along its axis determined by the rod 38 in the guide 39, according to a possibility of oscillation of a few degrees on either side of an average position in which the axis II-II is parallel to the axis II of the support drum 3. The motor 41 is controlled by a control device as a function of produced signals by two feelers 43 and 44 detecting the position of the opposite edges of the abrasive strip 6. The device is adapted so that, when one of the feelers, for example feeler 43, detects a movement of the abrasive strip 6 in the direction of the corresponding end of the return drum 5, the motor 41 is actuated to produce a pivoting of the caliper 37 and of the return drum 5 in a direction causing the abrasive belt 6 to return towards the center of the return drum 5.

The sections with elastic surface, for example sections 35 and 36, consist of a metal drum portion, namely the core 33, covered with a grooved surface layer of elastic material of hardness between 35 and 90 Shore A.

In the embodiments comprising a driving drum 17, this driving drum being coated with coaxial elastic rings such as the rings 170-173, distributed over its length, it is advantageously possible to provide a particular distribution of the rings making it possible to further increase the possibilities planning a ski with a convex or concave transverse profile.

For this, as shown in FIGS. 6 and 7, with regard to one of the elastic sections 35 or 36, for example with regard to the elastic section 36 of the support drum 3, the driving drum 17 comprises two elastic rings 171 and 172 consecutive lines separated from each other by a space 174. The space 174 is advantageously equal to approximately half the distance separating the two lateral dimension lines of an alpine ski. The lateral dimension lines of an alpine ski being spaced from 65 to 95 millimeters, a space 174 equal to approximately 30 to 40 millimeters may be suitable. The two elastic rings 171 and 172 then constitute two lateral support zones, improving the planning of a ski with a concave transverse profile.

Similarly, with regard to one of the elastic sections, for example the elastic section 36 of the support drum 3, the driving drum 17 comprises two lateral spaces or zones 174 and 175 devoid of rings and separated by a zone central equipped with two rings 172 and 173. The central zone provided with two rings 172 and 173 has a width equal to approximately half of the distance separating the two lateral dimension lines of an alpine ski, that is to say approximately 30 to 40 millimeters. A central support zone is thus produced, improving the planning of a ski with a convex transverse profile.

The architecture of the device according to the present invention also allows, without appreciable increase in the total volume of the device, to adapt an additional section of support drum allowing a special machining to achieve the fall of the edges. Thus, Figures 6 and 7 illustrate such an embodiment in which, on the same axis II, is adapted, in extension of the support drum 3, an additional section 45 with elastic surface. The additional section 45 is not intended to be surrounded by the same abrasive strip 6, but is surrounded by a particular circular abrasive strip pressed over its entire periphery against the section 45, and having a width at least equal to that of downhill skiing. The circular abrasive band is of an aggressive type for the steel forming the ski edges, and less aggressive for the polyethylene gliding sole. The additional section 45 is integral in rotation with the support drum 3, and has substantially the same outside diameter as the support drum 3. The drive drum 17 has a length sufficient to be substantially equal to the total length of the assembly formed by the support drum 3 and the additional section 45.

In the embodiments comprising a driving drum 17, the support means which urge the driving drum 17 in the direction of the support drum 3 allow a fairly large clearance of the driving drum 17, so that the apparatus makes it possible to machine the lower sliding surface of a ski without removing the bindings which are screwed onto the upper surface of the ski. For this, a straddle is adapted on the upper surface of the ski, and the assembly formed by the ski and the straddle is passed between the driving drum 17 and the support drum 3.

The same technique is used for the machining of a snowboard: the straddle can be positioned along the median longitudinal axis of the snowboard, or can be offset laterally, allowing the sanding of the lower surface of the board snow in several passes, even in cases where the snowboard has an unsettled bottom surface.

The sanding operations of a lower sliding face of a ski generally require several stages during which the sanding means must work according to distinct parameters.

In particular, the running speed of the abrasive belt 6 can advantageously be between 5 and 15 meters per second for surface finish finishing steps, and between 15 and 30 meters per second for roughing steps or planning.

The running speed of the ski, provided by the driving drum 17, is advantageously between 4 and 6 meters per minute during a rough surface finish step, and between 8 and 12 meters per minute for a step finishing.

The support force of the driving drum 17 in the direction of the support drum 3, for alpine skiing, can be of the order of 200 newtons for the roughing stages, and of the order of 100 newtons for the stages of surface finish. When machining a snowboard, the contact force can be kept equal to approximately 300 Newtons even for the stages of surface finish.

For a planning step, carried out by means of the additional section 45, the high speed of rotation of the support drum 3 is preferably used, that is to say a tangential speed of between 15 and 30 meters per second, a bearing force of approximately 150 to 200 newtons, and a ski movement speed of between 4 and 6 meters per minute.

We realize that, depending on the type of product to be sanded and the current machining step, the settings to be made on the functional elements of the device are quite numerous. Adjustment faults can lead to the production of inappropriate surface conditions, and can possibly lead to the risk of accidents, the ski being able to be suddenly pushed back by the device instead of being driven in the normal direction.

To solve these difficulties, the present invention provides automatic control means, ensuring complete adjustment of the functional elements of the device according to the operations to be performed on the ski. According to an advantageous embodiment, the apparatus according to the invention comprises means for recognizing the presence of a ski, the type of ski to be sanded as a function of its width, and the type of operation that the user wants to perform on this ski. The type of ski is recognized according to its width, by feelers. The presence of the ski and the type of operation are recognized by detecting the position that the ski occupies along the axis of the drums. For this, in the embodiment illustrated in Figure 2, there are 4 pedals 310 to 313 similar to the pedal 310 shown in the figure, articulated around the same transverse axis 320 of the frame 1. The pedals are pushed up by means elastic not shown, and are each supported on a lever actuating one of the four switches 300 to 303 similar to the switch 300 shown. If reference is made to FIGS. 6 and 7, the pedals 310 to 313, not shown, are positioned at the input of the device respectively opposite the zones defined by the sections 35, 34, 36 and 45 of the support drum 3, and are each of width less than the respective sections of support drum 3. Thus, when engaging an alpine ski in the device on the area 35 of support drum 3, the ski presses on the pedal 310 which actuates the switch 300. When the same alpine ski is engaged in the area 34, the switch 301 is actuated. It is the same respectively when the ski is engaged on zones 36 or 45, actuating the switches 302 or 303. A monoski or a snowboard, of width more important than an alpine ski, automatically causes the actuation of two successive pedals. One or more of the four pedals 310 to 313 urged by the ski to be machined actuate the respective switches 300 to 303 which send the information to a control circuit, housed in the frame 1 and not shown in the figures. The control circuit can be based on relays, electronic circuits, or any technology within the reach of those skilled in the art to fulfill the desired functions of controlling the functional members such as the motor 7, the motor 41 for centering, the carriage motor 30, the movable stop 32, the water spraying means 9.

The water spraying means 9 can advantageously be arranged so as to spray water only on the strip zones opposite the pedal or pedals which have been actuated. Water spray is thus limited to only the areas where this is useful, and the band cooling effect obtained by this water is concentrated in these areas.

• lorsque le circuit de commande reçoit un signal du commutateur 300, pour un cycle d'ébauche de ski alpin, il provoque la rotation rapide du moteur 7 et de la bande abrasive 6, une rotation lente du moteur d'entraînement de tambour entraîneur 17, et le déblocage du vérin 31 par la butée 32 pour produire une force d'appui faible ou moyenne du tambour entraîneur 17 sur le ski ;
• lorsque le circuit de commande reçoit un signal provenant du commutateur 301, pour une étape de finition de ski alpin, il provoque une rotation lente du moteur 7 et de la bande abrasive 6, une rotation 5 rapide du moteur d'entraînement de tambour entraîneur 17, et le déblocage du vérin à gaz 31 par la butée mobile 32 pour diminuer la force d'appui du tambour entraîneur 17 sur le ski ;
• lorsque le circuit de commande reçoit un signal provenant du commutateur 302, pour un cycle de planification de ski, il commande une rotation rapide du moteur 7 et de la bande abrasive 6, une rotation lente du moteur d'entraînement de tambour entraîneur 17, et un blocage du vérin 31 par la butée mobile 32 pour assurer une force d'appui élevée ou moyenne du tambour entraîneur 17 sur le ski ;
• lorsque le circuit de commande reçoit un signal provenant d'au moins deux des commutateurs 300 à 302, pour un cycle d'ébauche de planche à neige, il produit une rotation rapide du moteur 7 et de la bande abrasive 6, une rotation lente du moteur d'entrainement de tambour entraîneur 17, et un blocage du vérin 31 par la butée mobile 32 pour assurer une force d'appui élevée du tambour entraîneur 17 sur le ski ;
• lorsque le circuit de commande reçoit à la fois un signal provenant d'au moins deux des commutateurs 300 à 302 et un signal provenant d'un commutateur de finition actionné par l'opérateur et non représenté, pour un cycle de finition de planche à neige, il provoque une rotation lente du moteur 7 et de la bande abrasive 6, une rotation lente du moteur d'entraînement de tambour entraîneur 17, et un blocage du vérin 31 par la butée mobile 32 pour conserver une force d'appui élevée du tambour entraîneur 17 sur le ski ;
• lorsque le circuit reçoit un signal provenant du commutateur 303, pour une étape de tombé des carres du ski alpin, il provoque une vitesse de rotation rapide du moteur 7 et du tambour d'appui 3 portant la bande circulaire du tronçon supplémentaire 45, une vitesse de rotation faible du moteur d'entraînement de tambour entraîneur 17, et un déblocage du vérin à gaz 31 par la butée mobile 32 pour l'application d'une force d'appui faible ou moyenne du tambour entraîneur 17 sur le ski.

For example, the pedals 310 to 313 respectively actuate the four switches 300 to 303 selecting the appropriate settings for the four respective zones defined by the sections 34, 35, 36 and 45 of the support drum 3, so that:

• when the control circuit receives a signal from the switch 300, for an alpine ski roughing cycle, it causes the motor 7 and the abrasive belt 6 to rotate rapidly, the drum driving motor 17 to rotate slowly, and the release of the jack 31 by the stop 32 to produce a low or medium bearing force of the drum coach 17 on the ski;
• when the control circuit receives a signal from the switch 301, for an alpine skiing finishing step, it causes a slow rotation of the motor 7 and of the abrasive belt 6, a rapid rotation of the drive motor of the driving drum 17 , and the release of the gas spring 31 by the movable stop 32 to reduce the bearing force of the driving drum 17 on the ski;
• when the control circuit receives a signal from the switch 302, for a ski planning cycle, it controls a rapid rotation of the motor 7 and of the abrasive belt 6, a slow rotation of the drive motor of the driving drum 17, and a blocking of the jack 31 by the movable stop 32 to ensure a high or medium bearing force of the driving drum 17 on the ski;
• when the control circuit receives a signal from at least two of the switches 300 to 302, for a snowboard roughing cycle, it produces a rapid rotation of the motor 7 and of the abrasive belt 6, a slow rotation of the drive drum driving motor 17, and a blocking of the jack 31 by the movable stop 32 to ensure a high bearing force of the driving drum 17 on the ski;
• when the control circuit receives both a signal from at least two of the switches 300 to 302 and a signal from a finishing switch actuated by the operator and not shown, for a snowboard finishing cycle , it causes a slow rotation of the motor 7 and of the abrasive belt 6, a slow rotation of the drive motor of the driving drum 17, and a blocking of the jack 31 by the movable stop 32 to maintain a high bearing force of the drum coach 17 on the ski;
• when the circuit receives a signal from the switch 303, for a step of falling from the edges of alpine skiing, it causes a rapid rotation speed of the motor 7 and of the support drum 3 carrying the circular strip of the additional section 45, a speed low rotation of the driving drum driving motor 17, and an unlocking of the gas spring 31 by the movable stop 32 for the application of a weak or medium bearing force of the driving drum 17 on the ski.

During a step of rough drafting of alpine ski surface condition, the user passes the ski between the driving drum 17 and the support drum 3 in an area of abrasive band corresponding to the section longitudinal 35 having an elastic peripheral surface. For a "sanding with stone" or finishing step, the user passes the ski opposite the strip portion corresponding to a section with rigid peripheral surface such as section 34. For a finishing or roughing step of a snowboard, the user passes the snowboard simultaneously over the entire width of the abrasive strip corresponding to the three sections 34, 35 and 36 of the support drum 3. For a step of falling edges, the user passes the ski between the driving drum 17 and the additional section 45.

For an alpine ski planning step, the user passes the ski opposite the strip portion corresponding to a section with elastic peripheral surface such as the section 36. If the ski sole has a concave or tiled transverse profile, the user centers the ski in front of the space 174 separating the rings 171 and 172. The ski is then supported by its lateral zones on the two rings 171 and 172. The absence of support between the two rings 171 and 172 in space 174 concentrates the bearing force of the sanding on the left and right lateral zones of the ski sole to facilitate planning of the ski.

If, on the contrary, the ski sole has a convex or curved transverse profile, the user centers the ski opposite the rings 172 and 173 bordered by the spaces 174 and 175 devoid of rings. The sanding support force is then concentrated on the central area of the ski, to help plan the ski.

The arrangement of the means for recognizing the presence and type of ski and of the type of operation to be performed has been described in association with a particular structure of a multifunctional abrasive belt sanding tool according to the invention. However, such means can be provided on different multifunction tools, for example without an abrasive strip.

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 (14)

1 - Apparatus for sanding skis, comprising: - a frame (1) resting on the ground and supporting the functional organs, - a support drum (3), rotatably mounted along a first horizontal axis (II), and forming a support zone (4) accessible to receive the ski surface to be sanded, - a return drum (5), rotatably mounted along a second horizontal axis (II-II) offset from the first axis (II), - an abrasive strip (6) stretched between the support drum (3) and the return drum (5), tensioning means for urging at least one of the drums (5) away from the other (3) and tensioning the abrasive strip (6), - motor means (7) for rotating the support drum (3) and the abrasive belt (6), - water circulation means (9, 10) for spraying water onto the zone (4) of abrasive band surrounding the support drum (3) and for collecting the water flowing on the abrasive band, characterized in that : - The support drum (3) comprises at least a first (35) and a second (34) successive longitudinal sections each having a length greater than the width of an alpine ski, and having different surface hardnesses, namely a first section (35) with elastic surface having a peripheral area made of an elastic material, and a second section (34) with rigid surface having a peripheral area made of a rigid material such as aluminum, the abrasive strip (6) simultaneously covers all the successive sections (34, 35, 36) of the support drum (3), - The motor means (7) are arranged to rotate the support drum (3) according to at least two different suitable rotational speeds corresponding respectively to a first roughing or flattening step in which the ski surface is sanded at high tape travel speed, and a second finishing step in which the ski surface is sanded at low tape travel speed, - The return drum (5) is associated with means for centering the abrasive belt (37-44), to guide said abrasive belt (6) and ensure its maintenance in the vicinity of a position substantially centered on the return (5) and support (3) drums. 2 - Apparatus according to claim 1, characterized in that the section with elastic surface (35) consists of a metal drum portion (33) covered with a grooved surface layer of elastic material of hardness between 35 and 90 Shore AT. 3 - Apparatus according to one of claims 1 or 2, characterized in that: the support drum (3) comprises three successive sections, namely a first end section (35) with elastic surface, a second central section (34) with rigid surface, and a third end section (36) with elastic surface, - The total length of the support drum (3) and the total corresponding width of the abrasive strip (6), are greater than the width of a snowboard. 4 - Apparatus according to any one of claims 1 to 3, characterized in that it further comprises a driving drum (17), rotatably mounted along a third horizontal axis (III-III), movable between a raised position in which it is away from the support drum (3) to allow the introduction of the end of a ski, and a drive position in which it is brought closer to the support drum (3) and stressed in its direction by support means (18) for pressing a ski and keeping it in abutment against the abrasive belt (6), the driving drum (17) being biased in rotation by a driving motor. 5 - Apparatus according to claim 4, characterized in that: the support means (18) are adapted to produce at least two distinct support forces, a low force and a high force, - The drive motor is adapted to produce at least two distinct drive speeds, namely a slow speed and a fast speed. 6 - Apparatus according to one of claims 4 or 5, characterized in that the driving drum (17) is mounted on a carriage (18) sliding on guides (25-28) vertical side. 7 - Apparatus according to claim 6, characterized in that the sliding carriage (18) rests freely on a cam (29) ensuring its vertical actuation, the cam (19) being driven by a electric trolley motor (30) controlled by at least one switch (300), an impulse printed on the switch causing the completion of a complete cam cycle according to a rise and a fall of the driving drum (17). 8 - Apparatus according to claim 7, characterized in that: a gas spring (31) bears under the sliding carriage (18) to push it upwards according to a predetermined force, - A retractable stop (32) makes it possible to retain the jack rod (31) in the low position or to authorize its pushing movement of the carriage (18). 9 - Apparatus according to any one of claims 1 to 8, characterized in that: - it comprises a support drum (3) and a return drum (5) arranged along two axes (II; II-II) located substantially on the same vertical plane (IV-IV), - the driving drum (17) possibly provided is also arranged along an axis (III-III) located in the same vertical plane (IV-IV), - the motor (7) for driving the support drum (3) is housed between the support (3) and return (5) drums, and between the two abrasive belt blanks (61, 62) (6 ) connecting said drums (3, 5). 10 - Apparatus according to any one of claims 1 to 9, characterized in that it comprises at least one folding input table (15), articulated on the frame (1) and supporting, in the horizontal deployed position, the ski before it passes between the support (3) and driver (17) drums, the table (15) can be folded vertically against the frame (1). 11 - Apparatus according to any one of claims 1 to 10, characterized in that the support drum (3) comprises an additional section (45) with elastic surface surrounded by a circular abrasive strip pressed over its entire periphery and having a width at least equal to that of a ski, the circular abrasive band being of an aggressive type for the steel forming the edges of the ski and less aggressive for the polyethylene gliding sole,
so that the device comprises a support drum area (3) allowing the edges to fall. 12 - Apparatus according to any one of claims 1 to 11, characterized in that it comprises a control device comprising a series of pedals (310-313) articulated on the frame (1) and actuating a series of switches (300-303) corresponding to several basic cycles such as: - an alpine ski roughing cycle, with a high belt speed, a low ski drive speed, a low or medium bearing force, - an alpine ski finishing cycle, with a low belt speed, a high ski drive speed, a low bearing force, - a ski planning cycle, with a high band speed, a low ski training speed, a high or medium bearing force, - a snowboard roughing cycle, with a high belt speed, a low ski drive speed, a high bearing force, - a snowboard finishing cycle, with a low belt speed, a low ski drive speed, a high downforce. 13 - Apparatus according to any one of claims 1 to 12, characterized in that: the driving drum (17) is coated with coaxial elastic rings (170) distributed over its length, - with regard to one of the elastic sections (35, 36) of the support drum (3), the driving drum comprises two elastic rings (171, 172) consecutive separated from each other by a space (174 ) equal to approximately half the distance separating the two lateral dimension lines of an alpine ski, constituting two lateral support zones for planning a ski with a concave transverse profile. 14 - Apparatus according to any one of claims 1 to 13, characterized in that: the driving drum (17) is coated with coaxial elastic rings (170) distributed over its length, - with regard to one of the elastic sections (35, 36) of the support drum (3), the driving drum comprises two lateral zones (174, 175) devoid of rings and separated by a central zone provided with rings (172, 173) and of width equal to approximately half the distance separating the two lateral dimension lines of an alpine ski, constituting a central support zone for planning a ski with a convex transverse profile.

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