WO2008049218A1

WO2008049218A1 - Device for mounting a ski on an atv in place of a front wheel

Info

Publication number: WO2008049218A1
Application number: PCT/CA2007/001892
Authority: WO
Inventors: Umed Panu; Michael Nanowski
Original assignee: Lakehead University
Priority date: 2006-10-25
Filing date: 2007-10-24
Publication date: 2008-05-02

Abstract

A ski assembly for mounting in place of a front wheel of an ATV can be installed quickly and easily due to a mounting device that makes use of existing ATV components to support the ski. The mounting device includes a rigid body provided with holes arranged to fit over the threaded studs of the existing wheel hub so that the ski assembly is installed in the same manner as the wheel it is replacing.

Description

DEVICE FOR MOUNTING A SKI ON AN ATV IN PLACE OF A FRONT WHEEL

This application claims the benefit of US Provisional Application no. 60/862792 filed October 25^th 2006.

This invention relates to a mounting device for supporting a ski in place of the front wheel of an ATV for use on the snow, and more particularly to a mounting device adapted for connection to the ATVs existing wheel hub. BACKGROUND OF THE INVENTION

With the constant increasing price of recreational ATVs, consumers are not receiving the optimum use of their machines, considering the initial financial investment. For consumers to be able to run their machines throughout the year, there is a need for a simplified quick-change attachment for a ski unit in replacement for the front wheels.

The idea of adapting ATVs for snow use is already in the public realm. That is, systems which allow a consumer to attach skis to the ATV for the winter season are already known.

Conversion kits are known that allow for a ski to be fastened on top of a front tire, without removing the tire. This is accomplished by strapping the ski to the tire by means of extending cables over the tire along an upper portion of its circumference and attaching them at each end to the ski disposed beneath the tire.

In addition, US 6,615,939 (Karales) describes an ATV Track Conversion which mentions in passing that the front wheel may be removed and replaced by a ski but focuses in the detailed disclosure on an endless track conversion for the rear of an ATV. US Patent 6,095,275 (Shaw) discloses the replacement of the wheel by a ski assembly which includes a support member extending from a housing that fits over and fastens to the ATV front end spindle. From the figures, it appears that installation of the ski assembly requires more than just removal of the wheel, that is just the rim and tire, as suggested by the description, but also the removal of associated components such as the wheel hub and brake rotor. As such, swapping of the wheel and ski may be require significant time and effort.

With the conventional known cable design, any abrupt turn or unexpected contact may cause the rubber tire to flex and break free of the harness. Another disadvantage of the cable mount is that it may take quite a bit of knowledge and experience to set up the cables around the circumference of the wheel. The wheel may also need to be fairly new with large treads, in order to keep the cables from slipping off.

The pin mount is the most material efficient mount wherein a support leg is pinned to an existing wheel carrier. The effective use of material allows this mount the advantage of being much lighter in the snow. However, mounting it to the ATV axle is more difficult than it appears to be. The barring system is complex and requires extremely tight machining tolerances. The bearings also need ongoing maintenance, which is financially burdensome in the light of increasing manufacturing costs. SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a ski mounting device for supporting a ski on a front wheel hub assembly of an ATV, where the wheel hub assembly comprises a hub supported about an axis, a plurality of threaded studs spaced circumferentially about the axis and extending from the hub in a common direction parallel to the axis and nuts for engagement with the threaded studs to secure a front tire on the ATV

According to the invention the ski mounting device comprising: a rigid body having an upper portion adapted for connection to the hub assembly and a lower portion adapted for connection to the ski, the upper end of the rigid body having a plurality of holes therethrough sized and arranged to receive the threaded studs of the hub assembly such that each threaded stud extends through a respective one of the holes to allow engagement of the stud with a respective one of the nuts on an outwards side of the rigid body opposite the hub to secure the rigid body to the hub; whereby, through connection of the lower portion of the rigid body to the ski, the mounting device allows installation of the ski in place of the front wheel of the ATV without removal of the hub. Preferably the rigid body comprises a plate.

Preferably an opening is provided in the upper portion of the rigid body between the holes for receiving an end of an axle assembly extending through the hub along the axis thereof.

Preferably the opening extends fully through the rigid body between opposite sides thereof.

Preferably, with the rigid body secured to the hub, a portion of a perimeter of the opening between circumferentially adjacent ones of the holes is disposed radially outward therefrom with respect to the axis.

Preferably a portion of a perimeter of the opening between circumferentially adjacent ones of the holes is disposed radially outward therefrom with respect to a central axis of the opening.

Preferably through-holes are provided in the rigid body to reduce the weight thereof. Preferably portions of the rigid body are recessed from an inward side thereof opposite the outward side to receive respective portions of the hub.

Preferably each of the holes passes through a respective one of the recessed portions of the rigid body.

According to a second aspect of the invention there is provided a ski assembly for mounting on a front wheel hub assembly of an ATV, the wheel hub assembly comprising a hub supported about an axis, a plurality of threaded studs spaced circumferentially about the axis and extending from the hub in a common direction parallel to the axis and nuts for engagement with the threaded studs to secure a front tire on the ATV, the assembly comprising: a ski mounting device comprising a rigid body having an upper portion adapted for connection to the hub assembly and a lower portion adapted for connection to the ski, the upper end of the rigid body having a plurality of holes therethrough sized and arranged to receive the threaded studs of the hub assembly such that each threaded stud extends through a respective one of the holes to allow engagement of the stud with a respective one of the nuts on an outwards side of the rigid body opposite the hub to secure the rigid body to the hub for pivotal motion about the rotational axis thereof; and a ski connected to the lower portion of the ski mounting device for movement therewith; whereby the ski assembly can be installed in place of the front wheel of the ATV without removal of the hub.

Preferably there is provided a shock absorber connected at one end to the ski for connection at an opposite end to a wheel carrier on which the hub assembly is supported.

Preferably the shock absorber is connected to the ski between the ski mounting device and a curved front end of the ski.

According to a third aspect of the invention there is provided a method of installing a ski in place of a front wheel of an ATV comprising the steps of: removing the front wheel from the ATV by removing nuts securing the front wheel to a respective hub assembly from threaded studs of the hub assembly and moving the front wheel along the threaded studs away from a hub from which the threaded studs extend; aligning holes in a ski mounting device with the threaded studs of the hub assembly and moving the ski mounting device along the threaded studs toward the hub at least until the threaded studs pass fully through the holes; threading the nuts back onto the threaded studs to secure the ski mounting device to the hub; and supporting a ski on the ski mounting device below the hub assembly

Preferably there is provided a step of connecting a shock absorber between the ski and a wheel carrier on which the hub assembly is supported.

The disclosure involves a simple mounting device, or adapting bracket, that allows a user to easily mount snow-machine skis in place of the front wheels on a rear-wheel driven ATV. The device provides a reliable connection between the ski and the ATV by means of threaded fasteners rather than cables which may break free as described herein above. The reliability of this connection in no way depends on the condition of the ATV tires, as the tires are removed before installation. Furthermore, as the device is installed in the same manner as the tire being replaced by the ski, installation requires no specialized knowledge beyond the ability to mount a tire. By using the existing wheel hub to support the device, installation time is minimized as no modification of the ATV is necessary beyond removal of the wheel, unlike the systems of Shaw and Karales et al. which require removal of the ATVs front hub assemblies. As a result, the ski mounting device of the present invention offers a quick and easy interchange from tires to skis allowing the ATV a far greater flotation on all snow-covered terrains. The ski mount bracket is designed such that it can be easily be adapted to a variety of brands of ATV.

This attachment would have users on their way in, literally, minutes. As far as cost effectiveness is concerned, the design would be cast or machined without extremely tight tolerances, and yet, it would still be able to bare the load put upon it. When all of the alternative designs are examined and weighed on the criteria of cost, assembly, and maintenance, then the ski mount offers the consumer the best value and safety. For these reasons, this new rigid body design described in detail hereinafter will encompass improvements over the prior art ski mounting arrangements. BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:

Figure 1 is an isometric view of a ski assembly in accordance with the present invention installed in place of a front wheel of a four-wheeled ATV.

Figure 2 is an isometric view of a body of the ski mounting device of the ski assembly of Figure 1.

Figure 3 is an elevational view from the side of the body of Figure 2.

Figure 4 is an isometric view of the ski assembly of Figure 1 viewed from the opposite side and prior to installation.

Figure 5 is an isometric view of a ski assembly of Figure 4 when installed in place of the front wheel of the four-wheeled ATV.

In the drawings like characters of reference indicate corresponding parts in the different figures. DETAILED DESCRIPTION

The figures show ski assemblies installed onto front end components of a conventional four-wheeled ATV in place of a front wheel. The front end components illustrated in Figure 1 are part of a suspension used to support the front wheel. An upper control arm 10 and lower control arm 12 are each pivotally connected to the frame of the ATV (not shown) to allow up and down motion of the wheel relative thereto. As illustrated, the upper control arm 10 is an A-arm which curves back along itself to provide two joints 10A, 10B at an inboard end for pivotal connection to the frame. Similarly, the lower control arms 12 is an A-arm having two inboard joints 12A, 12B. The control arms 10, 12 extend laterally from the frame to support a wheel carrier 14 between them. The wheel carrier 14 is a steering knuckle connected to a tie rod (not shown) operatively connected to a steering column (not shown) to provide steering control to a driver. The joint 1OC between the upper control arm 10 and the wheel carrier 14 is a ball joint, and similarly, the joint 12C between the lower control arm 12 and wheel carrier may also be a ball joint. The relative motion needed between the wheel carrier and the arms to allow smooth upward and downward motion of the wheel is provided by the three rotational degrees of freedom of the ball joints. A spindle 16 extends outward from the wheel carrier 14 in a direction opposite the control arms to support a wheel hub 18 for rotation about a longitudinal axis of the spindle 16. The wheel hub 18 acts to support the wheel for rotation about the spindle axis for rolling motion of the ATV over the ground. Threaded studs 20 extend outward from the wheel hub 18 parallel to the spindle axis away from the wheel carrier 14. Respective holes are provided in the ATV wheel rim such that moving the wheel toward the hub with the axis of each hole aligned with a respective threaded stud 20 mounts the wheel on the ATV as the rim hangs from the studs. The wheel is secured into place by nuts threaded onto the studs to clamp the wheel rim against the hub. The threaded studs 20 are typically located on the hub 18 so as to be circumferentially spaced about the spindle, or rotational, axis when in use (i.e. installed on the spindle). As shown, the hub 18 is formed to have spokes 18A extending outward about a center hole, through which the spindle passes, to support the threaded studs 20 in their positions spaced circumferentially about the spindle axis. This spoked structure has less mass than a circular hub having the same thickness profile in radial directions and a large enough diameter to support the threaded studs in the same positions.

The ski assembly 30 of the present invention improves the ease of mounting a ski in place of a front wheel of an ATV by making use of the existing wheel mounting components, or hub assembly, of the ATV. The mounting device 32 includes a rigid body 34 of rigid material having an upper portion for attachment to the existing wheel hub assembly and a lower portion attached to a ski 35. The upper portion has holes 36 extending therethrough having the same relative spacing as the threaded studs 20 extending from the hub. In other words, the mounting holes in the rigid body have the same spacing as, and similar size to, the holes provided in the ATV wheel being swapped for the ski assembly. The result is that the mounting device is a direct swap for the wheel. Installation requires only removal of the wheel and installation of the rigid body 34 onto the hub assembly in the same manner as wheel installation. No further modification of the ATV front end components is required. For example, suspension and brake components such as a brake rotor and associated calliper can remain in place and unmodified on the ATV without interfering with function of the ski assembly. As illustrated, the rigid body 34 may have a plate-like structure in that its thickness is substantially less than its width and height (thickness and width denoting dimensions measured across and along the ski respectively). While the thickness must be sufficient to provide the mount with enough strength to handle loading thereof by the ATV during use, keeping it relatively thin allows use of the existing threaded studs 20 to support the ski assembly by ensuring that they protrude from the rigid body on the side opposite the hub 18 for engagement with securing nuts. Should the thickness of the body exceed the length of the threaded studs between their free ends and the hub, suitable replacements is provided through installation of longer wheel studs or bolts. Avoiding unnecessary thickness also prevents adding unnecessary weight to the ski assembly, as it is desirable to keep the vehicle's weight relatively low.

An opening 38 is provided in the upper portion of the rigid body spanning outward from the longitudinal axis of the spindle 16 to accommodate an end thereof, which may include a bolt and cap, extending from the hub 18 away from the wheel carrier 14. While the opening is illustrated as extending entirely through the thickness of the body 34, it should be appreciated that the necessary depth of the opening is determined by how far the spindle end protrudes from the hub 18. For example, where the length of this protrusion from the hub is less than the thickness of the body, the opening 38 may simply be a recess provided in the side of the body nearest the hub sized to receive the spindle end without contact between the spindle end and surrounding body. Providing the opening as a through-hole however, provides flexibility in that the mounting device can be used with an ATV having a spindle end of any length. The through-hole also acts to reduce the weight of the body more than a recess of the same peripheral shape.

As will be appreciated, weight reduction associated with material removal or reduction provided by the opening 38 can be increased by increasing the size of the opening, but such expansion is limited by the need for material to support the body on the threaded studs of the hub assembly. Therefore, in the illustrated embodiments, the opening 38 includes lobes which extend outward from its center beyond the circumference on which the threaded studs 20 and respective holes 36 lie between adjacent studs along the circumference. In other words, a radial distance from the longitudinal spindle axis to the threaded studs is less than a radial distance from that axis to the ends of the lobes of the opening. This increases the size of the opening 38 while providing sufficient material around the holes 36 to safely support the ski assembly on the threaded studs.

A lower portion of the rigid body 34 disposed below the opening 38 and mounting holes 36 includes a plurality of openings 40 extending through the body 34 and spaced thereacross. Spacing between the openings 40 forms support legs 42 extending upward from a bottom edge 44 of the body 34 to support the upper portion thereof. The openings 40 reduce the weight of the body but the legs 42 ensure that enough strength is provided to support the ATV during storage and use. At the bottom edge 44 of the lower portion, the body is fastened to the ski 35, which is a conventional snowmobile ski. Different methods of affixing two components are well known to those of skill in the mechanical arts and Figure 5 shows one possible connection between the ski and mount. As illustrated in the figure, the ski 35 includes a backbone 46 having vertical walls 48 extending along the side edges 50 of the ski. A support shelf 52 extends horizontally between these side walls 48 along a portion thereof extending parallel to the ski beneath it. Holes 54 extend upward through the bottom of the rigid body 34 into two of the openings 40 which are situated directly above the support shelf 52. Corresponding holes in the support shelf are aligned with those in the body 34 so that bolts 56 can be passed through the aligned holes and threaded with respective nuts to clamp the body and shelf together to support the ski on the mounting device. Alternatively, the holes in the shelf are threaded to allow direct engagement between the bolt and shelf. Providing at least two bolts prevents pivoting of the body 34 relative to the ski 35 about a longitudinal axis of one of the bolts. The support shelf 52 is provided with vertical flanges through which the support shelf and attached mounting body 34 are bolted to the side walls of the ski backbone 46.

As shown in figure 4, the rigid body 34 is recessed on its hub side so that the hub 18 is partially recessed into the rigid body with the two components overlapping. With the hub 18 having the spoked form, this recessing may take the form of separate recesses 60 each provided in a region about a respective one of the mounting holes 36. As such, the periphery of each recess 60 forms a wall that encloses the end of the respective spoke. It will be appreciated that the body 34 of the mounting device is easily adapted to properly fit with any of a wide variety of hubs, and although illustrated with a curved upper edge 62 and straight side edges 63A and 63B (either vertical or sloped), the body may be formed to have any of a number of shapes.

The mounting assembly includes a shock absorber 64 pivotally connected at opposite ends to the ski 35 and the wheel carrier 14. The shock absorber 64 is connected to the ski 35 by means of a lug 66 provided on the ski to which the shock absorber is pinned. Alternatively, for example as shown in Figure 5, the shock absorber is pinned to one of the vertical walls 48 of the ski backbone 46. An extension may need to be fastened to the wheel carrier 14 in order to provide a suitable pivot point for attachment of the shock absorber that will allow the shock absorber to function properly and not interfere with other components of the ATV or the ski mounting assembly. Figure 5 shows such an extension provided in the form of a plate-like bar 65 extending forward and downward from the wheel carrier to establish a connection point for the shock absorber forward of a brake rotor and below a brake calliper of the ATV. Positioning such an extension in such a way that it will not interfere with ATV components during operation with a wheel installed on the hub 18 allows a onetime installation of the extension without need for detachment/attachment each time the ski mounting assembly is removed/installed. The shock absorber 64 acts to both limit motion of the ski 35 with pivoting of the hub 18 and mounting body 34 about the spindle axis and provide shock absorption upon impact of the ski with the ground. The shock absorber 64 extends forward from the wheel carrier 14 to connect to the ski 35 between the carrier and a curved tip 68 of the ski. It should be appreciated that a range over which the body is allowed to pivot may be limited in other ways, for example by mechanical limitation provided by physically blocking movement of the spokes of the hub 18 passed a predetermined angular limit.

The ski assembly of the present invention can be mounted in place of a front wheel of an ATV simply by removing the wheel and installing the ski assembly in its place. First, the nuts engaged to the threaded studs of the hub assembly are removed to release the wheel which is then pulled away from the hub over the threaded studs. The holes in the mounting device of the ski assembly, which match those of the wheel, are aligned with the threaded studs and the body is slid thereover toward the hub so as to hang therefrom by means of the studs. The nuts removed to release the wheel are then threaded back onto the studs to clamp the rigid body against the hub for support thereon and movement therewith. In cases where a shock absorber is provided, the free end opposite the ski is connected to the wheel carrier for pivotal motion. During the first time the assembly is mounted on the ATV, this may require the installation of a mounting extension to provide a suitable connection point for the shock absorber. The extension should be installed so as not to interfere with existing ATV components so that it can remain in place when the wheel is later remounted without being detrimental to operation of the vehicle. The result is that the ski assembly and wheel can be quickly and easily swapped for operation of the ATV in different environmental conditions.

After extensive testing on various ramps and different snow covered terrain such as, moguls and snow banks, the ski mount of the present invention has proven to be a rugged design, possible of taking large sudden impacts.

Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

Claims

CLAIMS:

1. A ski mounting device for supporting a ski on a front wheel hub assembly of an ATV, the wheel hub assembly comprising a hub supported about an axis, a plurality of threaded studs spaced circumferentially about the axis and extending from the hub in a common direction parallel to the axis and nuts for engagement with the threaded studs to secure a front tire on the ATV, the ski mounting device comprising: a rigid body having an upper portion adapted for connection to the hub assembly and a lower portion adapted for connection to the ski, the upper end of the rigid body having a plurality of holes therethrough sized and arranged to receive the threaded studs of the hub assembly such that each threaded stud extends through a respective one of the holes to allow engagement of the stud with a respective one of the nuts on an outwards side of the rigid body opposite the hub to secure the rigid body to the hub; whereby, through connection of the lower portion of the rigid body to the ski, the mounting device allows installation of the ski in place of the front wheel of the ATV without removal of the hub.

2. The ski mounting device according to Claim 1 wherein the rigid body comprises a plate.

3. The ski mounting device according to Claim 1 or 2 wherein an opening is provided in the upper portion of the rigid body between the holes for receiving an end of an axle assembly extending through the hub along the axis thereof.

4. The ski mounting device according to Claim 3 wherein the opening extends fully through the rigid body between opposite sides thereof.

5. The ski mounting device according to Claim 3 or 4 wherein, with the rigid body secured to the hub, a portion of a perimeter of the opening between circumferentially adjacent ones of the holes is disposed radially outward therefrom with respect to the axis.

6. The ski mounting device according to Claim 3 or 4 wherein a portion of a perimeter of the opening between circumferentially adjacent ones of the holes is disposed radially outward therefrom with respect to a central axis of the opening.

7. The ski mounting device according to any one of Claims 1 to

6 wherein through-holes are provided in the rigid body to reduce the weight thereof.

8. The ski mounting device according to any one of Claims 1 to

7 wherein portions of the rigid body are recessed from an inward side thereof opposite the outward side to receive respective portions of the hub.

9. The ski mounting device according to Claim 8 wherein each of the holes passes through a respective one of the recessed portions of the rigid body.

10. A ski assembly for mounting on a front wheel hub assembly of an ATV comprising a ski mounting device according to any one of claims 1 to

10 and a ski connected to the lower portion of the ski mounting device for movement therewith whereby the ski can be installed in place of the front wheel of the ATV without removal of the hub.

11. The ski assembly according to Claim 10 further comprising a shock absorber connected at one end to the ski for connection at an opposite end to a wheel carrier on which the hub assembly is supported.

12. The ski assembly according to Claim 10 or 11 wherein the shock absorber is connected to the ski between the ski mounting device and a curved front end of the ski.

13. The ski assembly according to Claim 10 or 1 1 wherein the shock absorber is connected to a backbone member of the ski.

14. The ski assembly according to any one of Claims 11 to 13 wherein there is provided an extension portion for connection between an upper end of the shock absorber and the wheel carrier.

15. The ski assembly according to any one of Claims 10 to 14 wherein a bottom end of the rigid body is fastened to a backbone member of the ski.