Convertible ski-supported vehicle

Abstract

Wheel unit on the ski of a snowmobile. Wheels are readily deployable or retractable as ground surface conditions require. The wheel unit allows the snowmobile to be driven over gravel, dirt, and hardtop surfaces, while maintaining steerability with the handlebars. The wheel unit is a separate assembly that is detachably mountable on the ski or is an integral component of the ski.

Description

[0001] This application is a Continuation-in-Part (CIP) of U.S. patent application Ser. No. 09 / 818,058, filed on Mar. 26, 2001.BACKGROUND INFORMATION[0002] 1. Field of the Invention[0003] The invention relates to the field of ski-supported vehicles. More particularly, the invention relates to snowmobiles equipped with wheels that will allow the snowmobile to travel readily over surfaces not covered with snow or ice.[0004] 2. Description of the Prior Art[0005] Snowmobiles are vehicles that are constructed to travel across snow and ice. As is generally known, the snowmobile is driven by an endless drive track arranged at the rear end of the underside of the snowmobile. The front end of the snowmobile is supported and rides along two skis, which glide across the surface of the snow or ice. The skis typically have a carbide runner that runs along a portion of the bottom surface of the ski, to help keep the snowmobile traveling along a smooth track.[0006] A disadvantage of snowmobiles is...

AI Technical Summary

Benefits of technology

[0012] The objects are achieved by providing a road wheel unit that is semi-permanently installed on the ski of a conventional snowmobile so as to provide a set of wheels that are easily deployable or retractable as the conditions require. In a retracted position, i.e. the standard snowmobile mode of operation, the wheels are carried alongside the ski, raised above the gliding surface of the ski. In a deployed position, the wheels are lowered, so that the weight of the machine is supported by the wheels. The wheels in this deployed position hold the ski above the rolling surface of the wheels, and allow the snowmobile to ride on wheels and the conventional endless track at the rear end. In the latter mode, the snowmobile remains readily steerable with the handlebars and the carbide runners on the ski surfaces are not subject to excessive wear. The wheels are easily detachable from the mounting means, leaving the mounting means permanently installed on the vehicle, without impairing the functionality of the skis.

[0014] The kingpin-mount wheel unit includes a kingpin to replace the conventional kingpin to which the ski spindle attaches, a wheel mounting bracket mounted on each side of the kingpin. The deployment means is mounted onto the wheel mounting bracket, outside the ski. In the case in which a pair of wheels is mounted on one ski, i.e., one wheel on each outer side of the ski, a crossbar is used to connect ends of each of the side rails to form a movable frame. In this way, grasping the crossbar and moving the frame results in the cams on both wheel units being moved simultaneously.

[0015] A locking mechanism is provided in the ski to ensure that the side rail is locked into the respective deployed-wheel or retracted-wheel position. In a simple locking mechanism used on the kingpin-mount wheel unit, a yoke depends from the crossbar into the inner contour of the ski. The bottom portion of the yoke latches into the latching mechanism that is mounted on the floor of the ski. To deploy the kingpin-mount wheel unit, a person lifts the ski by the handle that is typically provided at the front end of the ski, grabs hold of the crossbar and slightly lifts and slides it forward toward the front end of the ski until the yoke latches in the latching mechanism. The two wheels, one on each side of the ski, are thereby lowered and secured in the deployed position. The snowmobile can now be driven across gravel and hardtop surfaces without losing its ability to be steered with the handlebars.

[0017] In some cases, it is desirable to mount the wheel unit on the side wall of the ski, rather than on a kingpin. The side wall-mount wheel unit is provided for this purpose. A mounting plate is mountable on the side wall and the wheel-mounting bracket is mounted on a spindle that extends from the mounting plate. As with the kingpin-mount wheel unit, either one wheel or a pair of wheels is mounted on each ski. Again, if a pair of wheels is mounted on the ski, a crossbar links the distal ends of the side rails, so that moving the crossbar causes both side rails to move simultaneously, thereby ensuring that the wheels are deployed / retracted simultaneously.

Problems solved by technology

A disadvantage of snowmobiles is that the skis don't readily glide across gravel, hardtop, or other non-snow surfaces.

This makes it difficult, if not impossible, to steer a snowmobile because the skis do not respond properly to the steering operations initiated at the handlebars.

Furthermore, when a snowmobile is driven or dragged across a non-snow surface, the carbide runners on the skis are subject to excessive wear and must be replaced more frequently, depending on how often a snowmobile travels across a non-snow surface.

This inability to steer snowmobiles on surfaces other than snow and ice makes it difficult for people to maneuver their snowmobiles across roadways, driveways, onto ferries, etc.

Also, now that such lengthy trips are being undertaken with snowmobiles, the presence of snow along the entire route is not guaranteed, and consequently, snowmobiles are being required more and more frequently to travel some distance across surfaces other than snow or ice.

Now, however, with the need to travel several miles along a roadway to get to a filling station, the inability to steer a snowmobile has become a major obstacle in the logistics and the enjoyment of the sport.

Both methods of converting the snowmobile to a wheeled vehicle involve a fair amount of work.

Thus, such conversion kits are not generally an acceptable solution to the problem of having to change in relatively quick succession back and forth between a vehicle that rides on skis and one that rides on wheels, as happens when traveling over gravel or hardtop or other surface other than snow or ice to fill the gas tank or to load onto a ferry.

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