GB2159112A - Adapting a wheeldriven vehicle for tracked vehicle use - Google Patents

Abstract

A wheel-driven vehicle can be adapted for tracked vehicle use by use of a support frame (9) detachably mounted on the vehicle. The frame has rotatably mounted thereon at least one pair of jockey wheels (6, 7) and a ground engaging endless track (10). The jockey wheels (6, 7) are not directly driven from the vehicle drive means. In use, the ground engaging endless track embraces both the vehicle wheel and the jockey wheels so that a direct drive to the vehicle wheel is also imparted to the endless track. The track (10) may consist of a pair of spaced belts with a hub sprocket and chain drive to the jockey wheels, Figures 5-8 not shown. <IMAGE>

Description

SPECIFICATION Apparatus for adapting a wheel of a driven vehicle for tracked vehicle use This invention reiates to an apparatus for adapting a wheel of a driven vehicle for tracked vehicle use.

Vehicles, in particular tractors, have been modi- fied and adapt'ed for travelling over terrain of-dif ferent types. ;For travelling over marshy or bog-like terrain, thew'heels of tractors have been adapted so as to enable the use bf caterpillar-type tracks.

While significantly improving the capability of travel over such terrain, the use of such tracks ih the known manner does not permit their use in' very marshy or bog-like terrains particularly when the tractor is towing a trailer having a load of say 1.5 tonnes.

Caterpillar tracks, when mounted on a tractor, re quire the use of the brakes for steering the tractor.

Accordingly, the tractor cannot function in a'four wheel-drive mode as the driving sprocket of the track is of a snnaller diameter than the replaced rea'r wheel and so the driving sprocket will rotate much slower than the front driving wheel.

It is an object of the present invention to provide a solution to this problem. It is a further object of the present invention to enable a vehicle such as a tractor to be used as a tracked vehicle.

The invention therefore provides an apparatus fpr adapting a wheel of a driven vehicle for tracked vehicle use said apparatus comprising a support frame detachably mounted on the ve vehicle, the said support frame having rotatably mounted thereon by least one pair of jockey wheels which are not diredly driven from the vehicle drive means, a ground engaging endless track adapted in use to operatively embrace both the vehicle wheel and the said jockey wheels on the support frame whereby a direct drive imparted to the vehicle wheel by the vehicle drive means is imparted to the endless track to operatively actuate the said endless track to move the vehicle.

The invention will be understood in greater de tail from the following description of a preferred embodiment thereof given by way of example only and with reference to the accompanying drawings in which:- Figure 1 is a side elevation of a tractor having a first embodiment of the apparatus according to the invention mounted thereon; Figure 2 is a front elevation of the tractor of Fig ure 1; 'Figu"re'g is a plan view of the tractor of Figure 1 with the ground engaging tracks removed; Figure 4 is a side elevation of a tractor having a .second''e(nb'odiment of the apparatus according to the invention mounted thereon; Figure 5 is a perspective view of the apparatus of Figure 4;; Figure 6 is a front perspective view of the appa ratus of Figure 4; Figure 7 is a'perspective view taken from the front showing the mechanism for mounting the ap paratus of Figure 4 on the tractor; and 'Figure 8 is a plan view of the apparatus and trac -tor of Figure 4. Referring now to the drawings and in particular to Figs 1-3 thereof, there is shown a tractor 1 hav- ing a first embodiment:of the apparatus 2 accord ing to the invention attached thereto. As can be.

seen from the drawings, the apparatus 2 is shown in two-different but essentially similar construc tions so forlhe sake of clarity, a description of the apparatus on the rear -or-- right hand side-of- the tractor As viewed in Figure 1 'will 'be -given,. the nu meral references-in the following description -being applicable to the apparatus on the front of the trac tor except for minor differences which should be immediately apparent.

The apparatus 2 on the rear or-right.hand side of the tractor as viewed in Figure 1-comprises a relatively large wheel 3 having a cage-like frame 4 and an axle 8. Theframe-4 has a plurality of shaped re cesses'S-lo-cated equidistant on the periphery thereof. The apparatus 1 also comprises two pairs of jockey wheels or rollers 6, 7 located-forwardly and rearwardly respectively -of the wheel 3. De pending from the axle 8 of the wheel 3 is a pair of -T-shaped connecting beams 9 which serve to support the rollers 6, 7.An endless articulated track 10 is provided having a plurality of projections.5a thereon forengaging with the recesses 5 of the wheel 3. The track 10 also-passes around the roll- ers 6, 7 in a conventional manner The apparatus 2 is attached to the tractor 1 in a conventional manner by means of a hub mecha nism 12 which permits the axle 8 to rotate freely.

Attached to the hub mechanism 12 is a second T- shaped beam 13 which:in elevation (Figure 1) slopes downwardly in the direction-of.the wheels 6, 7 and in plan (Figure 3) tapers from the hub mechanism 12 to the-wheels 6, 7.. Essentially, at its broadest, in-plan, thb beam 13 is adapted for lim-- ited rotaion-aboutrthe. hub;mechanism 12. The de gree of rotation abaut the-hub mechanism 12. The degree of rotation is controlled by a-spring 1.4 lo cated between and attached to the tractor 1 and the beam t3 which generally biases the apparatus -2 ititO a median position relative to the tractor 1.

To facilitate up and down movement of the appa ratus 2 relative-to the tractor 1., an axle-20,is,pro- vided. The degree of up and-down movement is limited by a stop member 21 fitted to.the axle 20.

As will be seen from-the drawings, the.essential difference between the apparatus 2 mounted on the rear of the tractor:and -the .apparatus 2 at the front of the tractor is that the epparatus.2:atthe front or left hand side as side as viewed'-in..Eigure.1:.has..

only one pair of rollers 6a. In addition,-thehub mechanism 12a not only' permits rotation of the axle 8 but also enables the apparatus 2.to move relative to the tracto-f;1; -tosteer- the tractor. The axle 20 and the spring 64 ate absent from-the device 2 at the front of the tractor and it is; therefore, more-ri-gidly attached thereto. Furthermereeras best seen-ih Figure 2 of the drawings, the width of the track 10 of the apparatus 2 at the front of the trac- tor is considerably less-that-the width of.-tbe-traeks on the device 2 at the rear of the tractor.

In use, the apparatus 2 is mounted on the tractor 1 in place of the conventional wheels thereon. By incorporating appropriate mounting means, the conventional wheels of the tractor may be easily removed and replaced with the device 2 according to the invention when the need arises and vice versa.

In a conventional tractor of about 70-80hp or a tractor having a conventional caterpillar track arrangement, the tractor exerts a pressure on the ground of about 1.70 p.s.i. However, by mounting the apparatus 2 according to the invention onto the tractor, a force as low as 0.95 p.s.i. is exerted by the tractor on the terrain and when the tractor is towing a load of say 1.5 tonnes, the force exerted is as low as 1.31 p.s.i.

Referring now to Figures 4-8 of the drawings, there is shown a second embodiment of the apparatus according to the invention. The apparatus comprises a wheel 100 and a support frame 101 having two parallel beams 102, 103 linked by a third beam 103a. A pair of axles 104, 105 is mounted between the beams 102, 103 the axle 105 being additionally supported by a third beam 105a.

The beam 102 has additional conventional structures generally shown in Figure 7 for detachable mounting the frame 101 to a tractor 110. In particular, the beam 103 has components 107 welded thereto which components 107 include hub plates 108 for engaging with one of the hubs 109 of the tractor110 by means of bolts 111. The axle 104 at the front has a pair of jockey wheels 112, 113, mounted thereon. Also mounted on the axle 104 is a drive wheel or sprocket wheel 115 so that all three wheels may rotate simultaneously. The axle 105 at the rear has a pair of jockey wheels 116, 117 mounted thereon.

Each of the jockey wheels 112,113,116,117 has a plurality of projections 118 located equidistant on the circumference thereof. The projections 118 are adapted for interengagement with belts 119, 120.

The sprocket wheel 115 is adapted for engaging with a drive chain 121.

The wheel 100 has a pair of channels 122, 123 for guiding respective belts 119, 120. Located centrally on the wheel 100 is a sprocket system including sprocket teeth 130 for engaging with the drive chain 121. Mounted transversily on the belts 119, 120 is a plurality of track members 124 which track members 124 are ground engaging when in use.

For reasons of clarity, the members 124 are not shown in Figures 6-8; in Figure 5, only one track member 124 is shown in position. It is important that the track members 124 should not be connected to the drive chain 121.

The wheel 100, being of the cage type, is mounted onto the hub 109 in a conventional manner being, in use, one of the driving wheels of the tractor. A similar wheel is mounted on the hub locrated on the opposite side of the tractor.

To use the apparatus according to the second embodiment of the invention, a pair of wheels 100 is mounted in a conventional manner on the tractor. With conventional wheels 150 mounted on the front of the tractor, the tractor may be used on reasonable firm ground in a conventional manner.

However, if it is desirable to use the tractor in marshy ground as previously described, the frame 101 is attached to the tractor in the manner described above. The chain 121 (which is open ended) and the belts 119, 120 (which are also open ended) and having track members 124 thereon are placed on the ground in the vicinity of the wheel 100. The tractor is moved so that the wheel 100 rides over the drive chain 121 and the belts 119, 120. The tractor having been driven sufficiently is stopped and the free ends of the drive chain 121 are connected in a conventional manner so that the drive chain 121 engages with the sprocket wheel 115 and the teeth 130 on the wheel 100. The belts 119, 120 are threaded around the jockey wheels 112, 116 and 113, 117 respectively. The free ends of the belts 119, 120 are connected in a conventional manner.

A similar apparatus is mounted on the corresponding wheel on the other side of the tractor.

Thus, each of the rear wheels of the tractor has now been converted relatively quickly and easily to enable the tractor to be used a track vehicle.

In use, the tractor motor drives each of the wheels 100. the driven wheel 100 drives the drive chain 121 via the teeth 130. The drive chain 121 drives the sprocket wheel 115 which in turn drives the jockey wheels 112, 113. Rotation of the jockey wheels 112, 113 drives the belts 119, 120 and this causes the track members 124 to move. With this arrangement and particularly with the wheels 100 acting a driving wheels, the tractor may be steered by the front wheels 150 in a conventional manner.

More particularly, all four wheels, i.e. the wheels 100 and the wheels 150 may function as drive wheels which, heretofore on a tracked vehicle, was extremely difficult if not impossible.

As in the first embodiment, the frame 101 is adapted to pivot relative to the wheel 100 by means similar to that described above.

Claims (10)

1. An apparatus for adapting a wheel of a driven vehicle for tracked vehicle use said apparatus comprising a support frame detachably mounted on the vehicle, the said support frame having rotatably mounted thereon at least one pair of jockey wheels which are not directly driven from the vehicle drive means, a ground engaging endless track adapted in use to operatively embrace both the vehicle wheel and the said jockey Wheels on the support frame whereby a direct drive imparted to the vehicle wheel by the vehicle drive means is imparted to the endless track to operatively actuate the said endless track to move the vehicle.

2. Apparatus as claimed in Claim 1 in which a drive wheel is mounted co-axially with one pair of jockey wheels and the drive imparted to the vehicle wheel is imparted by said vehicle wheel to the drive wheel whereby in operational use the jockey wheels are indirectly driven via the drive wheel to operatively actuate the endless track.

3. Apparatus as claimed in Claim 2 wherein the drive wheel is a sprocket wheel and the vehicle wheel is provided with a complementary mounted sprocket system such that a conventional drive chain, in use, embraces both the sprocket system and the drive chain thereby imparting drive from the vehicle wheel to the sprocket wheel.

4. Apparatus as claimed in Claim 2 of Claim 3 wherein the endless track comprises a pair of belt elements in parallel spaced apart relationship and a plurality of track members and wherein the track members are attached to, and mounted transversely of, the belt elements.

5. Apparatus as claimed in Claim 4 wherein the vehicle wheel has a pair of circumferentially spaced apart grooves each of which provides a guiding channel for a respective one of said belt elements.

6. Apparatus as claimed in Claim 5 wherein the sprocket wheel is mounted intermediate said one pair of jockey wheels and the sprocket system includes a plurality of sprocket teeth located circumferentially on the vehicle wheel intermediate the grooves.

7. Apparatus as claimed in Claim 6 wherein said one pair of jockey wheels and the sprocket wheel are mounted forwardly of the vehicle wheel.

8. Apparatus as claimed in Claim 7 wherein a second pair of jockey wheels is rotatably mounted on the support frame rearwardly of the vehicle wheel and wherein the endless track is adapted, in use, to operatively embrace the vehicle wheel, the forwardly mounted jockey wheels and the rearwardly mounted jockey wheels.

9. An apparatus substantially as hereinbefore described with reference to and as illustrated in Figs 1-3 of the accompanying drawings.

10. An apparatus substantially as hereinbefore described with reference to and as illustrated in Figs 4-8 of the accompanying drawings.