The present invention relates to a snow tiller for preparing ski slopes.

BACKGROUND ART

Normally, a snow tiller for preparing ski slopes is able to be drawn in a travelling direction along the ski slope, and comprises a supporting structure; and a shaft which is able to be rotated with respect to the supporting structure about an axis crosswise to the travelling direction, and is fitted with tools, each extending crosswise to the shaft axis.

Large snow tillers have the drawback of failing to adapt to the contour of uneven snow surfaces. To eliminate this drawback, large articulated tillers have been devised, which are divided into sectors, each with a supporting structure and a respective shaft. The supporting structures are connected by hinges with axes substantially parallel to the travelling direction, and the shafts are powered by respective motors connected to respective ends of the shafts.

In actual use, articulated tillers of the type described above are unable to work the part of the snow surface in the gap between the two supporting structures, thus resulting in poor grooming of the ski slope .

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a snow tiller for preparing ski slopes designed to eliminate the above drawback of the known art.

According to the present invention, there is provided a snow tiller for preparing ski slopes and able to be drawn in a travelling direction along the ski slope; the snow tiller comprising at least two supporting structures hinged to each other about at least one hinge axis; at least two shafts housed respectively in the supporting structures and able to be rotated about respective rotation axes crosswise to the travelling direction; tools fitted to the shafts; and at least one further tool connected at least to a shaft and located between the two supporting structures.

By virtue of the present invention, the tiller adapts readily to the terrain, while at the same time ensuring more even grooming of the ski slope as compared with the known art, by virtue of the further tool.

In a preferred embodiment, each shaft is supported by the respective supporting structure; the two supporting structures being coupled to each other by at least one articulated coupling allowing relative movement between the two supporting structures.

The articulated coupling allows the supporting structures to move and so adapt to the contour of the snow surface.

In another preferred embodiment, each supporting structure comprises respective bars; and a casing fixed to and supported by the respective bars.

In another preferred embodiment, the tiller comprises a supporting bar coupled to the supporting structures by further articulated couplings, so as to support the supporting structures and permit relative movements between the supporting structures and the supporting bar.

The articulated couplings result in a structure that adapts readily to the contour of the snow surface and therefore of the underlying terrain, thus enabling better grooming of the snow surface.

In another preferred embodiment, the further articulated couplings are designed to permit relative movements between the supporting structures in a direction perpendicular to the travelling direction.

In another preferred embodiment, the tiller comprises a joint connected to the shafts and designed to permit relative angular movements between the shafts.

In another preferred embodiment, the further tool is mounted on the joint, preferably at one end of the joint.

In another preferred embodiment, each shaft comprises a flange connected to the end of the joint; and the further tool is located on the joint and fixed to one of the two flanges.

In another preferred embodiment, the tiller comprises a blade defining further tools positioned 180° apart .

In another preferred embodiment, the blade has a hollow portion to permit assembly of the joint, and is fixed to one of the two flanges.

In another preferred embodiment, the tiller comprises a further blade defining another two further tools; the blade and the further blade being positioned at an angle of 90° to each other.

The two blades at 90° to each other thus provide a tool every 90°, to ensure thorough grooming of the snow surface .

BRIEF DECRIPTION OF THE DRAWINGS

A number of non-limiting embodiments of the present invention will be described by way of example with reference to the attached drawings, in which :

Figure 1 shows an underside view, with parts removed for clarity, of a snow tiller for preparing ski slopes in accordance with the present invention;

Figure 2 shows a larger-scale view in perspective, with parts removed for clarity, of a detail of the Figure 1 snow tiller; Figure 3 shows an underside view, with parts removed for clarity, of an alternative embodiment of the Figure 1 snow tiller. BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole a snow tiller for preparing ski slopes and able to be drawn in a travelling direction D by a snow groomer vehicle not shown in the drawings .

Snow tiller 1 is used to till a surface layer of the snow covering, and comprises a frame F, of which Figure 1 shows a supporting bar 2 extending parallel to an axis Al and crosswise to travelling direction D; two supporting structures 3 and 4 connected to supporting bar 2 by respective articulated couplings 5 allowing movement in a direction perpendicular to axis Al; and two shafts 6 and 7 supported by respective supporting structures 3 and 4. Shaft 6 extends along axis Al, and is coupled to supporting structure 3 to rotate about axis Al ; while shaft 7 extends along an axis A2, and is coupled to supporting structure 4 to rotate about axis A2. In Figure 1, axes Al and A2 are coincident. In actual use, axes Al and A2 may not be coincident, depending on the contour of the snow surface tiller 1 is working on. Tiller 1 also comprises a finish mat 8, which is normally flexible, is connected to supporting structures 3 and 4, extends behind shafts 6 and 7, and is drawn over the tilled snow surface.

Each supporting structure 3, 4 comprises two bars 9, 10 parallel to respective axis Al, A2; and articulated couplings 5 fixed to one bar 9, 10 to connect it to supporting bar 2 of frame F.

Supporting structure 3 comprises a casing 11. More specifically, casing 11 is in the form of an arc-shaped plate fixed crosswise to the two bars 9. Supporting structure 3 also comprises two supporting plates : an outer supporting plate 13 and inner supporting plate 14, which are fixed to the ends of the two bars 9.

Likewise, supporting structure 4 comprises a casing 12. More specifically, casing 12 is in the form of an arc-shaped plate fixed crosswise to the two bars 10. Supporting structure 4 also comprises two supporting plates : an inner supporting plate 15 and outer supporting plate 16, which are fixed to the ends of the two bars 10.

Shafts 6 and 7 are fixed to respective supporting plates 13, 14 and 15, 16 by bearings not shown in the drawings .

Tiller 1 comprises a joint 17 for connecting shafts 6 and 7; and articulated couplings 18 fitted to and between, to connect, inner supporting plates 14 and 15.

Supporting structures 3 and 4 are thus connected by articulated couplings 18, which allow relative movements of supporting structures 3 and 4 about a hinge axis A3 parallel to travelling direction D.

Joint 17 is designed to allow relative movements between shafts 6 and 7. Joint 17 is a constant-velocity universal joint. More specifically, joint 17 allows movement between shafts 6 and 7 in a direction parallel to travelling direction D. And joint 17 is located between the two inner supporting plates 14 and 15.

Tiller 1 comprises a number of tools 19 fitted to shafts 6 and 7. Each tool 19 extends crosswise to axis Al or A2. More specifically, tools 19 are defined by teeth 32 fixed to one of the two shafts 6 and 7. Teeth 32 are designed to sink into and break up the snow surface .

With reference to Figure 1, shafts 6 and 7 comprise respective hollow cylinders 20 and 21. Shaft 6 comprises two end flanges 22, 23 connected to opposite ends of hollow cylinder 20; two flanges 24, 25 integral with end flanges 22, 23 respectively; and seats 26 equally spaced along hollow cylinder 20 to house respective tools 19. Flanges 24 and 25 are fitted respectively to supporting plates 13 and 14 of supporting structure 3 by bearings not shown in the drawings .

Likewise, shaft 7 comprises two end flanges 27, 28 connected to opposite ends of hollow cylinder 21; two flanges 29, 30 integral with end flanges 27, 28 respectively; and seats 26 equally spaced along hollow cylinder 21 to house respective tools 19. Flanges 29 and 30 are fitted respectively to supporting plates 15 and 16 of supporting structure 4 by bearings not shown in the drawings .

Flanges 25 and 29 are also connected to joint 17. Flanges 25 and 29 each extend partly between supporting structures 3 and 4. More specifically, flanges 25 and 29 each extend partly between supporting plates 14 and 15.

Tiller 1 comprises four tools 19a on and on opposite sides of joint 17. The four tools 19a are located between supporting structures 3 and 4, and more specifically between supporting plates 14 and 15.

Tools 19a are defined by the appendixes of two blades 31 in the form of a rhomboid truncated at its acute angles. Blades 31 each have a hollow portion to permit assembly of joint 17, and are fixed to respective flanges 25 and 29 by bolts 40. In other words, each blade 31 is fixed directly to respective flange 25, 29 by bolts 40. More specifically, each blade 31 is fixed along a face of respective flange 25, 29. Each blade 31 forms two tools 19a at 180° to each other. And the two blades 31 are positioned at a 90° angle to each other.

In the example shown, shafts 6 and 7 are powered by respective electric motors not shown in the drawings. In which case, joint 17 serves to synchronize the rotation speed of shafts 6 and 7.

In an alternative embodiment, shafts 6 and 7 are powered by one electric motor connected directly to shaft 6 or 7. In which case, in addition to synchronizing the rotation speed of the two shafts, joint 17 also transfers rotation from the shaft powered directly by the electric motor to the other shaft.

Number 101 in Figure 3 indicates another embodiment of the tiller. All the parts of tiller 101 in common with tiller 1 are indicated using the same reference numbers. In this embodiment, joint 17 is omitted. So, the speed of shafts 6 and 7 is synchronized by a control unit controlling the motors (not shown) of shafts 6 and 7. Moreover, as opposed to blades 31 defining tools 19a, tiller 101 comprises blades 131 defining tools 119. Tools 119 are connected to respective shafts 6 and 7 and located between supporting structures 3 and 4. Tools 119 are preferably four in number : two connected to shaft 6, and two to shaft 7. The two blades 131 are fixed respectively to flanges 29 and 25. In other words, each blade 131 is fixed directly to a respective flange 25, 29. More specifically, each blade 131 is fixed along a face of respective flange 25, 29.

By virtue of tools 19a or 119, snow is groomed substantially evenly over the whole longitudinal extension of tiller 1. By virtue of the present invention, tools 19 and 19a or 119 are more or less equally spaced along axes Al and A2.

In an embodiment not shown, there are more than two shafts, more than two supporting structures, and more than two hinge axes.

Clearly, the present invention also covers embodiments not described in the above detailed description, as well as equivalent embodiments, which nevertheless fall within the protective scope of the attached Claims.