Snow groomer track and snow groomer featuring such a track

This application is a national stage application of PCT/EP2009/056582, filed on May 28, 2009, which claims the benefit of and priority to Italian Patent Application No. MI2008A 001001, filed on May 29, 2008, the entire contents of which are incorporated herein.

The present disclosure relates to a snow groomer track and a snow groomer.

As is known, a snow groomer is a crawler vehicle comprising a frame, to which are connected a shovel (at the front) and a snow grooming implement (at the rear).

Certain known snow groomers normally have two, sometimes four, tracks specially designed for moving over snow. More specifically, certain known snow groomer tracks comprise a number of grousers crosswise to the track traveling direction and connected at the blunt edges by one or more flexible annular belts. The grousers have respective grip portions, opposite the blunt edges, defined by blades which cut into the terrain to move the vehicle forward, and the size of the grousers crosswise to the traveling direction must be considerable, almost equal to the width of the frame, so the vehicle floats over the snow surface. That is, snow groomers frequently operate on deep layers of fresh snow, in which excessive sinking would make it difficult, if not impossible, for the vehicle to move forward; whereas, even on packed snow surfaces, such as used ski slopes, the track prints must be no more than superficial, so they can be removed in one go by the tiller. If the track prints are too deep, this could result in an uneven groomed snow surface, thus endangering users.

The tracks of these known snow groomers are driven by respective drive sprockets on the vehicle, which directly engage the gaps between adjacent grousers; and normally idle guide wheels support the track in the work configuration, by providing the necessary tension, and normally rest on one of the flexible belts.

Such known tracks have a number of drawbacks, mainly due to the drive sprockets working directly on the grousers. Foremost of these is poor traction, on account of the primary function of the grousers being that of gripping the terrain and enabling the vehicle to float. On the other hand, design of the grousers must also take into account connection to the drive sprockets, which in practical terms means strengthening the structure.

It is an object of the present disclosure to provide a snow groomer track and a snow groomer designed to eliminate drawbacks of certain known snow groomers, and which, in particular, provide for improving traction.

According to the present disclosure, there is provided a snow groomer track comprising a plurality of grousers extending crosswise to the traveling direction of the track and each having a grip portion for gripping the terrain, and a blunt edge opposite the grip portion, characterized by a chain connected to the blunt edges of the grousers so as to be engaged, in use, by a drive sprocket of a snow groomer.

According to a further aspect of the disclosure, the track comprises elastically deformable connectors for connecting the chain to the grousers in such a manner as to permit controlled relative rotation of the grousers with respect to the chain in a plane crosswise to the traveling direction of the track.

According to a further aspect of the disclosure, the chain comprises a plurality of links, and hinge connectors for hinge connecting pairs of adjacent links about respective hinge axes crosswise to the traveling direction of the track, and the hinge connectors are elastically deformable to permit controlled relative rotation of any two adjacent links about axes not coinciding with the respective hinge axis.

A drive sprocket of the snow groomer engages the chain of a respective track.

Additional features and advantages are described in, and will be apparent from, the following Detailed Description and the figures.

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

FIG. 1 shows a side view, with parts removed for clarity, of a snow groomer featuring a track in accordance with a first embodiment of the present disclosure;

FIG. 2 shows a larger-scale, three-quarter top view in perspective of a portion of the FIG. 1 track;

FIG. 3 shows a partly sectioned plan view of a portion of the FIG. 1 track;

FIG. 4 shows a side view of the FIG. 3 track portion sectioned along line IV-IV in FIG. 3 ; and

FIG. 5 shows a front view of a portion of a track in accordance with a second embodiment of the present disclosure.

Referring now to the example embodiments of the present disclosure illustrated in FIGS. 1 to 5 , number 1 in FIG. 1 indicates as a whole a snow groomer comprising a frame 2 ; a front shovel 3 ; and an implement 4 for grooming the snow surface M of a ski slope. Implement 4 is connected to the rear of frame 2 to be drawn by groomer 1 , and comprises, by way of example, a rotary snow tiller.

Snow groomer 1 comprises two tracks 5 (only one shown in FIG. 1 ) driven by respective drive sprockets 7 and guided by idle guide wheels 8 (four on each side of snow groomer 1 in the embodiment described).

As shown in FIGS. 2 , 3 and 4 , track 5 comprises a plurality of transverse grip bars, hereinafter referred to as grousers 10 , connected by one or more flexible belts 11 , and a chain 12 .

Grousers 10 are spaced apart in succession, extend crosswise to the traveling direction D of track 5 , and each comprise a support bar 14 and a blade 15 which defines a grip portion that cuts into the terrain (in particular, snow surface M) to ensure grip of track 5 . Blade 15 is welded or riveted to support bar 14 . Support bar 14 has a longitudinal cavity 14 a running through the entire longer dimension of grouser 10 , crosswise to traveling direction D. A portion of support bar 14 , opposite blade 15 , defines a blunt edge 10 a of grouser 10 . Flexible belts 11 are fixed to blunt edges 10 a of grousers 10 and one of flexible belts 11 serves as a support for guide wheels 8 .

Chain 12 is connected to blunt edges 10 a of grousers 10 , crosswise to traveling direction D, as explained in detail below, so as to be engaged, in use, by a respective drive sprocket 7 of snow groomer 1 to transmit motion to track 5 .

Chain 12 comprises a number of links 17 hinged to one another in pairs and connected to blunt edges 10 a of respective grousers 10 .

More specifically, each link 17 of chain 12 comprises two parallel bars 18 extending in traveling direction D of track 5 and connected by a crosspiece 19 perpendicular to them. Crosspiece 19 thus extends crosswise to traveling direction D of track 5 , and comprises a seat shaped according to blunt edges 10 a of grousers 10 . Links 17 are connected to respective grousers 10 by elastically deformable connectors that permit controlled relative rotation of grousers 10 with respect to chain 12 in a plane crosswise to traveling direction D of track 5 . In the embodiment described, the elastically deformable connectors comprise: threaded pins 22 projecting perpendicularly from blunt edge 10 a of respective grousers 10 and inserted through fastening holes 23 in crosspiece 19 of a respective link 17 of chain 12 , outwards of bars 18 , nuts 24 fitted to respective threaded pins 22 , and bushes 25 made of resilient material and housed inside fastening holes 23 , about respective threaded pins 22 . Threaded pins 22 of each grouser 10 are carried by a respective strip 27 housed inside longitudinal cavity 14 a of grouser 10 , and are fitted through openings 28 in blunt edge 10 a of grouser 10 . Bushes 25 are made, for example of rubber, deform when subjected to torque about axes not aligned with threaded pins 22 , and return to the undeformed configuration when stress is removed.

Pairs of adjacent links 17 of chain 12 are hinged to each other, about respective hinge axes A C crosswise to traveling direction D of track 5 , by elastically deformable hinge connectors to permit controlled relative rotation of any two adjacent links 17 about axes not coincident with respective hinge axis A C .

The hinge connectors comprise connecting pins 30 between pairs of adjacent links 17 , and hinge bushes 31 made of resilient material (e.g., rubber) and inserted between each link 17 of chain 12 and respective connecting pins 30 .

More specifically, each bar 18 has a first hinge hole 32 at a first end, and a second hinge hole 33 at a second end. In each link 17 , the second hinge hole 33 of the bar 18 on the side facing frame 2 of snow groomer 1 is a dead hole; and the second hinge hole 33 of the bar 18 on the outward-facing side is a through hole, as are first hinge holes 32 .

First hinge holes 32 and second hinge holes 33 each house a respective hinge bush 31 .

The first hinge holes 32 of each link 17 are aligned with the second hinge holes 33 of an adjacent link 17 , and house a respective connecting pin 30 inside hinge bushes 31 .

Connecting pins 30 define hinge axes A C and are each held in place between a wall of the dead second hole 33 , and a plate 35 inserted through the through second hole 33 .

In other words, each link 17 has a first end connected to an adjacent link 17 by a connecting pin 30 inserted inside first hinge holes 32 ; and a second end, opposite the first end, connected to a further adjacent link 17 by a further connecting pin 30 inserted inside second hinge holes 33 .

Hinge bushes 31 allow articulated movements between each pair of adjacent links 17 about axes not coincident with respective hinge axes A C , deform when subjected to torque about axes not aligned with respective hinge axes A C , and return to the undeformed configuration when stress is removed.

The gap between each two adjacent connecting pins 30 defines a seat which is engaged by a tooth 7 a of drive sprocket 7 connected to track 5 .

In a different embodiment of the disclosure shown in FIG. 5 , in addition to threaded pins 22 inserted inside respective fastening holes 23 and locked by nuts 24 , the elastically deformable connectors comprise a strip 125 of resilient material (e.g., rubber) interposed between each grouser 10 and seat 20 of respective link 17 of chain 12 .

Using the chain has the advantage of improving transmission of motion from the drive sprockets to the tracks, and so improving traction of the snow groomer. Moreover, the materials and construction characteristics of the grousers and chain can be selected independently, with no recourse to trade-offs which impair performance and resistance of the component parts. More specifically, the grousers are less subject to wear, thus prolonging the working life of the tracks. Another advantage lies in the modular design of both the grousers and the chain links, which means they can be replaced individually in the event of accidental damage or wear.

The elastically deformable connectors and hinge connectors enable optimum use of the chain on snow groomers in particular. Snow groomer tracks, in fact, are extremely wide, to enable the vehicle to float on soft, yielding terrain, such as snow. On the other hand, the large size of the tracks may result in potentially dangerous twisting and bending of the grousers at the join between the grousers and the chain links and between adjacent links. The elasticity of the connectors and hinge connectors, however, enables independent movement of the grousers and chain links, to adapt to uneven terrain, at least within given deformation limits and to the extent of slack allowed, thus greatly reducing stress.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.