Deployment system for wheel units on ski-mounted vehicles

A deployment system for wheel units on ski-mounted vehicles, and in particular for use with snowmobile skis having deployable wheel systems, that requires little manual effort to deploy and retract.

BACKGROUND INFORMATION

Field of the Invention

The invention relates to deployment mechanisms for wheel systems, particularly those that are used with ski-mounted vehicles such as snowmobiles.

Description of the Prior Art

Snowmobiles are commonly known vehicles that are constructed to travel across snow and frozen surfaces. 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 on two skis, which glide across the surface of the snow. The skis typically have a carbide runner that runs along a portion of the bottom surfaces, to help keep the snowmobile traveling along a smooth track.

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 on these surfaces, because the skis do not respond properly to the steering operations initiated at the handlebars.

Efforts to make snowmobiles mobile on gravel or other surfaces have been undertaken over the years. Prior art includes conversion kits to replace the skis with wheels and deployable wheels that are essentially permanently affixed to the snowmobile ski. The conversion kits were intended to replace the skis on a semi-permanent basis, that is, to convert a snowmobile into a wheeled vehicle for an extended period of time, typically requiring that the ski be removed in order to mount the wheels.

Deployable wheel systems cure a number of the conventional problems associated with the conversion kits, and the inventor of the present invention is also the inventor of several patents for wheel units for snowmobiles, U.S. Pat. No. 6,527,282, issued 4 Mar. 2003; U.S. Pat. No. 6,824,147, issued 30 Nov. 2005; U.S. Pat. No. 6,932,359, issued 23 Aug. 2005; U.S. Pat. No. 8,801,001, issued 12 Aug. 2014; and U.S. Pat. No. 9,180,800, issued Nov. 10, 2014, and all of which are incorporated herein in their entirety by reference.

Snowmobiles, however, tend to be heavy machines, with the average weight ranging anywhere from 500 pounds to 800 pounds, with much of that weight distributed directly above the skis. This weight has the effect of making it difficult for some users to deploy a deployable wheel system because the wheels must inherently elevate the front of the snowmobile in order for the wheels to deploy beneath the ski. Frequently a user must lift the ski, and thus the front end of the snowmobile, in order to deploy the wheel beneath the ski.

What is needed, therefore, is a deployment system that easily deploys the wheel unit despite the weight of the snowmobile.

BRIEF SUMMARY OF THE INVENTION

The invention is a wheel deployment system that requires relatively little effort by a user to deploy and retract wheel units on ski-mounted vehicles such as a snowmobile. The system uses a linkage assembly that is leveraged in a manner that allows the average users to deploy and retract the wheels from a seated position on the vehicle. The system may be manually operated or have an automated or semi-automated operating mechanism. The system may include a locking device to secure the wheels in their deployed or retracted position.

The wheel deployment system may be constructed on top, or be affixed to the top, of a conventional ski. In this embodiment, one or more openings are cut in the ski to allow wheels to pass through the ski from a retracted position above the ski to a deployed position below the ski. Alternatively, the wheel deployment system may be affixed to the side of a ski, with a floor of the ski remaining intact and the wheels deploying and retracting from a position beside the ski.

When the wheel units are in their retracted position they are above the bottom surface of the ski and the vehicle operates in a normal manner similar to a vehicle that does not have wheel units. When the wheels are deployed, the skis are lifted off of the ground surface so that on the wheels are in contact with the surface, and as a result the vehicle is easy to drive and maneuver on non-snowy surfaces such as gravel and pavement.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-5 and 9illustrate the first embodiment of a deployment system for wheel units on ski-mounted vehicles100according to the invention for use with a ski1000, shown inFIGS. 6-8 and 10. The deployment system100includes a support structure10, one or more deployable wheel units30, and a deployment assembly50. In this embodiment, the deployment assembly50is manually operated, and allows a user to deploy or retract the deployable wheel units30by simply lifting or pushing an actuation lever52. In a deployed state, the wheel units30extend below the ski and allow the operator to easily drive the vehicle, such as a snowmobile, on gravel or paved roads, maintaining control over the vehicle that is superior to a vehicle without wheels, and in a retracted state the wheels are elevated to a position above a bottom surface of the ski1000such that the vehicle operates like any other conventional vehicle. The design of the deployment assembly50allows for relatively easy deployment of the deployable wheel units30from a seated position on the vehicle, without the need for manually removing the ski1000and/or wheel units30, and without even needing to manually lift or elevate the skis1000.

The ski1000, shown inFIGS. 6-8, is a conventional ski having a ski body1010that is a molded, pressed, or stamped component. The ski body1010has a leading end1012and a trailing end1014, two side walls1016extending upward from a ski floor1018, and a bottom surface that is the ski glide surface. Whenever reference is made hereinafter to “front” or “rear” views of the various components and assemblies, “front” refers to the view facing the leading edge1012and “rear” refers to the view facing the trailing edge1014, when the component or assembly is incorporated into the wheel-unit ready ski1000.

The deployment system100may be incorporated into the ski1000, shown inFIGS. 6-8, in which case the support structure10may be affixed to the top surface of the ski1000with openings1020created in the ski1000to allow the wheel units30to deploy and retract through the ski1000. Alternatively, the deployment system100may be attached to the outer side of the ski1000sidewall1016, as shown inFIG. 10.

The embodiment shown includes a first wheel unit30A and a second wheel unit30B. The wheel units30may be in alignment, as shownFIG. 6where they are aligned near the middle of the ski1000, or they may be aligned along the left or ride side of the ski1000. The wheel units30may also be positioned in a non-aligned manner as shown inFIG. 8. It is also possible to construct the deployment system100using only one deployable wheel30, in which case the wheel would be positioned near the midpoint of the ski1000. Additional wheel units may also be incorporated. A snow guard39may be used to prevent snow from entering the area around the wheel units30.

In the embodiment shown inFIGS. 1-5, the support structure10is a conventional saddle or shoe, and includes a floor12and two sidewalls14. The floor12has been modified to include openings16for the deployable wheel units30. The support structure10is secured to the ski1000using conventional fasteners such as bolts and nuts as needed, and two openings1020are cut in the ski1000to allow the wheel units30to deploy and retract through the ski1000. In most instances, snowmobile skis1000have a kingpin KP that is used to attach the skis1000to snowmobile's steering assembly (not shown). The kingpin KP may be used to the further secure the support structure10to the ski1000, such that the kingpin passes through the sidewalls1016of the ski100and the sidewalls14of the support structure10. Additionally, carbide runners (not shown) are typically affixed to the bottom surface of the ski1000by a bolt that extends through the floor1018, exiting on the upper surface of the ski where it is secured by a nut. This carbide affixing means may also be used to secure the deployment assembly50.

In another embodiment the support structure10may be comprised of components that are integrated into the ski1000, as shown inFIGS. 8-10. In these instances, the deployable wheel units30and the deployment assembly50may be secured to the ski's sidewalls1016. In addition, or in the alternative, the wheel units30and deployment assembly50may be secured to the floor1018of the ski1000using conventional anchoring means such as an I-bracket1050. As previously explained, the carbide affixing means may also be used to secure the deployment assembly50.

Alternatively, the support structure10may be affixed to the outside of either side of the ski1000, for example, by being affixed to the outer portion of the sidewalls1016as shown inFIG. 10. In this instance, the King Ping KP has also been extended to further secure the deployment assembly50. n either instance, the support structure10is affixed to the ski S using conventional means such as nuts and bolts, screws, and/or brackets. And, again as previously explained, the carbide affixing means may also be used to secure the support structure10and/or deployment assembly50.

The wheel units30, best shown inFIGS. 1, 2 and 4, include a wheel32mounted on a cam plate34. A first position36on the cam plate34has a sub axle for mounting the wheel32, a second position38that is a coupling means for coupling the cam plate34to the deployment assembly50and a third position42for coupling the cam plate34to the support structure10. A second cam plate34A, having the same structure, may also be included, as shown with the first wheel unit30A.

The deployment assembly50is a manually operated assembly and includes an actuation lever52and a linkage assembly that includes a first coupling link54and a second coupling link56. The actuation lever52has a first end58that is accessible to a user and a second end62that is pivotably affixed to the support structure10. The first coupling link54is affixed to the actuation lever52and to the second coupling link56. The second coupling link56couples together the two wheel units30, connecting to each wheel unit30at the wheel units second position38.

In normal operations the actuation lever is positioned forward and the wheel units30are retracted and stored or contained within the support structure10. As the vehicle moves from a snow-covered surface to a non-snow-covered surface, such as a dirt or paved road, the operator pulls the actuation lever52upward and backward towards the rear of the ski. As the actuation lever52moves the coupling links54,56, deploy the wheels. More specifically, the actuation lever52exerts a force on the first coupling link54moving it from the lowered position shown inFIG. 2to the elevated position shown inFIG. 4. As the first coupling link54moves it in turn exerts a force on the second coupling link56, moving the second coupling link56backwards towards the rear of the ski1000in a relatively level plane. The movement of the second coupling link56causes the wheels units30to pivot into their deployed positions. As the vehicle re-enters a snow-covered surface, the actuation lever52is pushed forward and the wheel units30retract.

FIG. 9illustrates an embodiment of the deployment assembly50having the actuation lever52positioned near the wheel unit30that is in a forward position, closer to the front of the ski1000. The actuation lever52, first coupling link54and second coupling link56operate in the same manner as previously described. The second coupling lever56couples the two wheel units30as previously described.

FIG. 9also illustrates a locking mechanism80and a shock absorber90. In general, without a locking mechanism it is likely that the normal operation of the vehicle causes the wheel units30to move to a semi-retracted position, however, it is also unlikely that such operation is sufficient to cause the wheel units30to move all the way to a fully retracted position. The locking mechanism80secures the wheel nits30in their retracted or deployed position. The locking mechanism80includes a foot pedal82that operates a conventional latch84, the latch84secures an arm85that is attached to the second coupling link56in order to secure the wheel units30in the desired position. To deploy the wheel units30, the foot pedal82is pressed and the actuation lever52is pulled until the wheel units30are in the deployed position, after which the foot pedal82is released to secure the latch84and, as a result, the deployment assembly50and wheel units30. To retract the wheel units30the foot pedal82is pressed to release the latch84after which the lever52may be pressed forward to retract the wheel units30and the foot pedal may be released again when the wheel units30are fully retracted.

The shock absorber90is a conventional shock absorber that is affixed on one end92to the support structure10and on a second end94to deployment assembly50, and in particular is attached to the coupling means38. As the wheel units30are pulled into the retracted position the shock absorber90retracts and absorbs energy. When the locking mechanism80is released the shock absorber90is released and presses forward in a relatively slow manner so that the skis do not drop to a ground surface and a high speed.

Alternatively, or in addition, a conventional electrical control87, such as a solenoid, electrical motor, or electrical cam lock, may be used to release the latch84rather than the foot pedal82. The electrical control87is affixed to either the support structure10or the deployment assembly50and uses conventional components to trigger the latch84. The combination of an electrical control87with the shock absorber90is a semi-automated deployment system, whereby the shock absorber90provides enough force to cause the wheels to retract after the latch84is lifted. The latch84may also be a conventional spring-loaded latch, such that the force of the spring retracts the wheel units30in a semi-automated manner, i.e. the force of the spring is sufficient to cause the wheel units30to pivot into their fully retracted position.

An automated deployment assembly70is also shown inFIGS. 1-5, and includes a fluid-driven, i.e., pneumatically or hydraulically operated, drive unit comprising a cylinder72and a rod74. This type of actuator is well known in many industries. Thus, the details regarding the drive means for the deployment means are not shown. It is understood that a switch is provided on the control panel of the vehicle so that the operator may actuate the automated deployment assembly70while seated on the vehicle. The fixed end of the cylinder72is anchored to a bracket76on the ski1000and the operative end of the rod74is linked to the second position38on the first wheel units30A second cam plate34A. A third coupling link78, shown inFIG. 1, couples the rod74to the second coupling link56such that when the cylinder72actuates the rod74the third coupling link78operates the second coupling link so as to deploy the second wheel unit30B.

The manual deployment assembly50, semi-automated method, and the automatic deployment assembly70may all be included in a single deployment assembly or they may be provided individually or in any combination.

It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the wheel deployment system may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.