WO2006063440A1

WO2006063440A1 - A sprocket and track system for a motorcycle or the like

Info

Publication number: WO2006063440A1
Application number: PCT/CA2005/001880
Authority: WO
Inventors: Dany Bouchard; Steve Carignan; David Carignan
Original assignee: Atelier Carignan Inc.
Priority date: 2004-12-13
Filing date: 2005-12-12
Publication date: 2006-06-22
Also published as: CA2490093A1

Abstract

This invention relates to a sprocket and a track system for a motorcycle or other similar vehicle adapted to convert the rear wheel of a conventional two wheel vehicle to a track system. The track system includes a supplementary frame adjusted to the rear of the main frame of the motorcycle. A rotatable support wheel is adjustably secured to the free end of the backside portion of the frame in a spaced relation to the rear wheel of the motorcycle. A splittable sprocket is placed around the rim of the rear wheel in place of the tire. An endless track having an external surface and an inner surface operatively wraps around the sprocket and the support wheel.

Description

TITLE QF THE INVENTION

Sprocket and track system for a motorcycle or the like.

FIELD OF THE INVENTION

The present invention generally relates to a sprocket and a track system for vehicles, and more specifically to convert a conventional motorcycle or the like to a track system.

BACKGROUND OF THE INVENTION

The motorcycle has become a very popular open-air vehicle for sport, recreative and transport purposes, and is widely used in principally warm weather environment. In the winter conditions, the motorcycle might be unstable especially on snow, ice or slippery road surfaces. Similarly, dirt bike use is also popular where a motorcycle is used in off-road environments that often include travel over soft terrain.

It is known in the art that there are different runner attachments which allow adapting a motorcycle or bicycle for different weather and road conditions, whereby the same may be employed over snow and ice or soft terrain.

U.S. Patents No. 1,068,883 to Frank, issued on July 29, 1913 and No. 1,250,739 to Wells, issued on Dec. 18, 1917 describe early attempts to invent a runner attachment for two-wheeled cycles. There are also many more recent patents that attempt to resolve the same problems. U.S. Patents No. 6,279,923 to Cardillo et al., issued on August 28, 2001 describes a personal winter vehicle having a guide wheel rotatably attached to the frame and disposed in front of the drive wheel. A track is disposed around the guide and drive wheels, U.S. Patents No. 3,872,938 to DeGroot, issued on Mar. 25, 1975 and No. 5,474,146 to Yoshioka et al., issued on Dec. 12, 1995 describe devices which allow a conventional motorcycle to be used as a snow traveling vehicle.

The main problem with these devices is their complicated construction, and the need to make changes to the vehicle itself.

Thus, there is a need to develop a sprocket and a track system for a motorcycle or the like adapted to easily convert the rear wheel of a conventional two wheeled vehicle to a track system.

OBJECTS OF THE INVENTION

Accordingly, an object of the present invention is to provide a sprocket and a track system for a motorcycle or the like that obviates the above-mentioned disadvantages.

Another object of the present invention is to provide a sprocket and a track system which improves cycle-running performance on snow, ice surfaces or soft terrain. Still another object of the present invention is to provide a sprocket and a track system which allows adjusting the angle of the running surface of the track and the surface over which it travels.

A further object of the present invention is to provide a sprocket and a track system which can be easily adapted to a standard motorcycle or the like.

Still a further object of the present invention is to provide a track sprocket and a system which is not expensive.

Other and further objects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

SUMMARY OF THE INVENTION

To attain these and other objects which will become more apparent as the description proceeds according to one aspect of the present invention, a sprocket and a track system for a motorcycle or the like adapted to convert the rear wheel of a conventional two wheel vehicle to a track system is provided.

The track system for a motorcycle or the like according to the present invention consists of a supplementary frame which has a front portion customized to be adjusted to the rear of the main frame of the motorcycle or like, and a backside portion extending rearwardly of the rear wheel of the motorcycle. There is at least one support wheel and preferably a pair of support wheels adjustably secured to the free end of the backside portion of the frame in a spaced relation to the rear wheel, and an endless track having an external surface, and an inner surface operatively wrapping around at least part of the rear wheel and the support wheel to be powered by the rear wheel torque.

Preferably, there is at least one more support wheel or pair of support wheels adjustably connected to and extended downwardly from the supplementary frame to be in engagement with the inner side of the endless track between the rear wheel and the first support wheel.

Preferably, the external surface of the endless track is wider than the rear wheel rim and the support wheel(s) to decrease vehicle pressure on the ground.

Preferably, the front portion of the supplementary frame is angularly securingly adjustable to the main frame via an adjuster to allow a user to define the angle between the lower part of the track and the ground.

Preferably, there is provided a sprocket for embracing the rim of the rear wheel to be operatively wrapped by the endless track. The sprocket is made from at least two sections that are mutually continuously joined end to end into a circular form. At least one of said sections is preferably attached to said rim. Preferably, the sprocket includes a central rib extending around the exterior surface of the sprocket. Preferably, a plurality of spaced apart ribs extends transversely to say central rib.

The invention accordingly comprises the further of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and object of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

Figure 1 A is a first side view of a motorcycle equipped with a sprocket and a track system in accordance with the invention.

Figure 1 B is a second side view of the motorcycle shown in figure 1A.

Figure 2 is an exploded perspective view of an example of a track system according to the present invention.

Figure 3A is a right side perspective view of the track system shown in figure 2. Figure 3B is a left side perspective view of the track system shown in figure 2. Figure 4 is a detailed side view of the attachment means for attaching the frame of the track system to the main frame of the motorcycle,

Figure 5 is an exploded perspective view of an example of a sprocket securingly embracing the rim of the rear wheel according to the present invention.

Figure 6 is a top view of an example of the sprocket shown in figure 5.

Figure 7 is a side view of an example of the sprocket shown in figure 5, ^{': •}

Figured is a cross-sectional view taken from line A-A in Fig.7.

Figure 9 is a cross-sectiona! view taken from line B-B in Fig.7.

Figure 10 is a partial cross-sectiona I view taken from line C-C iri Fig. 6.

Figure 11 is an exploded perspective view of the tension wheel assembly shown in figure 2.

Figure 12 is an exploded perspective view of the support wheel assembly shown in figure 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the annexed drawings, the preferred embodiments of the present invention will be herein described for indicative purposes and by no means as of limitation.

As best shown in Figs. 1 , 2 and 3, the present invention relates to a track system for any conventional motorcycle or similar two wheel vehicle adapted to convert the rear wheel of a conventional two wheel vehicle M to a tracked traveling means of transportation and is generally indicated as 27.

This track system 27 comprises a supplementary frame 50 which has a front portion 51 customized to be securely adjusted to a main frame 2 of the motorcycle M or the like, and a backside portion of 56 extending therefore rearward to a rear wheel 28 of the motorcycle M. Preferably a pair of tension wheels 23, 24 (shown in figure 11) is adjustably secured to the free end 58 of the backside portion 56 of the supplementary frame 50 in a spaced relation to the rear wheel 28. Preferably, a support wheel 25 (shown in figure 12) is also used. An endless track 18 has an external surface 1S-A and an inner surface 18-B operatively wrapping around at least part of a sprocket 40 attached to the rear wheel 28 and around the support wheel 25 and the tension wheels 23, 24. The rear wheel 28 torque powers the endless track 18. Lower run portion 19 of the external surface 18-A engages the ground over which the vehicle travels.

As seen in figures 1A and 1B, the ground engaging portion 19 defines an angle α

with the ground. This angle α may be angularly securely adjusted to the main frame M via a processthat will be described hereunder. The magnitude of the angle α depends on the driving conditions and might be positive (figure 1A) or negative (figure 1B).

The angle α is adjusted by loosening the nuts/bolts 61, 62, 63 and 64 on each supplementary frame 50, A slight play between the bolts 62, 63, 64, 65 and the openings 52, 53, 54, 55 in the supplementary frame 50 allows the user to adjust the angle α according to his preference. The nuts/bolts 62, 63, 64 and 65 are then tightened.

To decrease vehicle pressure on the snow, the external surface 18-A of the endless track 18 is preferably wider than the rear sprocket 40, the tension wheels 23, 24 and the support wheel 25 as illustrated in figures 3A and 3B.

To convert a conventional two wheel vehicle M to a tracked vehicle, the existing tire [not shown] is removed from the rim 31 of the existing rear drive wheel 28 and is replaced by a sprocket 40 in accordance with this invention. The endless track 18 is placed over the sprocket 40, the tension wheels 23, 24 and the support wheeI25 and the additional frame 50 is attached to the swing arm 2 of vehicle M.

Figures 5 to 10 illustrate, with greater precision, one of the embodiments in which at least one sprocket 40 securely embraces the rim 31 of the rear wheel 28 to be operatively wrapped by the endless track 18. The sprocket 40 is preferably made from at least two sections 42 and 46 that are mutually continuously joined end to end into a circular form. The sprocket 40 includes a connecting means 44, 48 to secure the mutual joining of the sections 42 and 46. It is also preferable to attach at least one of said sections 42 or 46 to the rim using an attachment means 45.

As illustrated in Figure 5, the sprocket 40 has a central cylindrical rib 41 and a plurality of transversely extending ribs 49. Preferably these ribs matingly engage with complementary recesses (not shown) in the inner surface 18-B of the track 18.

When it's turning, the motorcycle's body is inclined on the side of the turning. To provide motorcycle smooth turning motion the ribs 49 have an external diameter D which diminishes from the central cylindrical rib 41 , defining an arch.

The endless track 18 is formed from resilient materials. The outer surface of the track 18 may be provided with different traction designs and shapes, which are well known in the industry, and we do not analyze it in the context of the present invention.

Although the suggested design allows use of many different vehicles, the exact configuration of the track system 27 depends on a specific vehicle design. The track system 27, the track 18 and the sprocket 40 may be offered in kits for different models of the motorcycie M. Once installed, the track system can be easily removed and the vehicle converted back to a conventional motorcycle.

The drawings and the description attached to it are only intended to illustrate the idea of the invention. As to the details, the invention may vary within the scope of the claims. So, the shape or size of the track system 27 adapted to convert a conventional two wheel vehicle M to a tracked means of transportation may be formed as desired, considering the needs and specificities of every vehicle.

The present track system has been adapted to convert a conventional two wheel vehicle to a tracked means of transportation and has been described with a certain degree of particularity. Although, it is to be understood that the disclosure has only been made as an example and that the present invention is not limited to the features of the embodiment(s) described and illustrated herein. It also includes all variations and modifications within the scope and spirit of the invention as hereinafter claimed.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A sprocket for attachment to the rim of a wheel of a motorcycle or the like wheel securely embraces the rim of the said wheel to be operatively wrapped by an endless track, said sprocket having an external surface and an internal surface,

2. The sprocket according to claim 1 , wherein the sprocket is made from at least two sections that are mutually joined end to end.

3. The sprocket according to claim 2, wherein the sections are removable.

4. The sprocket according to claim 2, wherein there is at least one attachment means to secure the sprocket to the rim.

5. The sprocket according to claim 3, wherein there is at least one attachment means to secure the sprocket to the rim.

6. The sprocket according to claim 4, wherein said attachment means comprise a tangentially extending hole near the extremity of each section and a bolt, screw or other similar means extending therein.

7. The sprocket according to claim 5, wherein said attachment means comprise a tangentially extending hole near the extremity of each section and a bolt, screw or other similar means extending therein.

8. The sprocket according to claim 2, wherein the sprocket includes a plurality of ribs disposed on the external surface of said sprocket.

9. The sprocket according to claim 3, wherein the sprocket includes a plurality of ribs disposed on the external surface of said sprocket.

10. The sprocket according to claim 4, wherein the sprocket includes a plurality of ribs disposed on the external surface of said sprocket.

11. The sprocket according to claim 8, wherein one of said ribs is centrally located and extending around the external surface of said sprocket.

12. The sprocket according to claim 9, wherein one of said ribs is centrally located and extending around the external surface of said sprocket.

13. The sprocket according to claim 10, wherein one of said ribs is centrally located and extending around the external surface of said sprocket.

14. The sprocket according to claim 8 wherein there are between 8 to 12 ribs transversely disposed on said external surface of said sprocket.

15, The sprocket according to claim 9 wherein there are between 8 to 12 ribs transversely disposed on said external surface of said sprocket.

16. The sprocket according to claim 10 wherein there are between 8 to 12 ribs transversely disposed on said external surface of said sprocket.

17. The sprocket according to claim 11 wherein there are between 8 to 12 ribs transversely disposed on said external surface of said sprocket.

18. A track system for a motorcycle or the like having a main frame, a front wheel and a rear wheel, said track system comprising:

a sprocket wheel adapted to replace said rear wheel; a supplementary frame having a front portion customized to De adjusted to said main frame and a back portion extending rearwardly therefrom; a first support wheel adjustably secured to the back portion of said supplementary frame in a space relation to said sprocket wheel; an endless track having an external surface operatively wrapped around part of said sprocket and said first support wheel and defining a ground engaging portion,

19. A track system as claimed in claim 18 wherein said ground engaging portion defines an adjustable engagement angle with said ground.

20. A track system according to claim 19, wherein the sprocket wheel comprises a rim portion and a sprocket portion and said sprocket portion includes a plurality of ribs disposed on the external surface of said sprocket portion.

21. A track system according to claim 20 wherein there are between 8 to 12 ribs transversely disposed on said external surface of said sprocket portion.

22.A track system according to claim 21 , wherein one of said ribs is located and extending around the external surface of said sprocket portion.

23. A track system according to claim 19, wherein there is a second support wheel is adjustably connected to and extending downwardly from the supplementary frame to be in engagement with the inner side of the endless track between the rear wheel and the first support wheel.

24.A track system according to claim 20, wherein the external surface of the endless track is wider than the rim portion and the support wheel.

25.A track system for a motorcycle or the like having a main frame, a front wheel and a rear wheel each having a rim, said track system comprising:

a supplementary frame having a front portion customized to be adjusted to said main frame and a back portion extending rearwardly therefrom; a first support wheel adjustably secured to the back portion of said supplementary frame in a spaced relation to said rear wheel; an endless track having an external surface and an inner surface operatively 'wrapped around at least part of the rim of said rear wheel and said first support wheel and defining a ground engaging portion.

26.A track system as claimed in claim 25 wherein said ground engaging portion defines an adjustable engagement angle with said ground.

27.A track system according to claim 26, wherein there is a second support wheel is adjustably connected to and extending downwardly from the supplementary frame to be in engagement with the inner side of the endless track between the rear wheel and the first support wheel.

28. A track system according to claim 26, wherein the external surface of the endless track is wider than the rear wheel rim and the support wheel.

29.A track system according to claim 19, wherein the front portion of the supplementary frame is angularly securely adjusted to the main frame via an adjuster to allow a user to define said engagement angle.

30. A track system as claimed in claim 26, wherein said sprocket is removable.

31.A track system as claimed in claim 26, wherein the sprocket is made from at least two sections that are mutually joined end to end.

32.A track system as claimed in claim 30 wherein there is at least one attachment means to secure said sprocket to said rim,

33.A track system as claimed in claim 32 wherein said sprocket includes a plurality of ribs disposed on the external surface of said sprocket.