GB2190338A

GB2190338A - Improvements in land vehicle propulsions

Info

Publication number: GB2190338A
Application number: GB08608000A
Authority: GB
Inventors: Peter John Sullivan
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-04-02
Filing date: 1986-04-02
Publication date: 1987-11-18
Also published as: GB8608000D0

Abstract

An assembly wheel can be mounted onto a land vehicle wheel hub or onto or alongside the wheel has an endless track (13) driven by the drive shaft of the vehicle wheel via a crown wheel (10) for example. The track (13) is made to run along a triangular path with a base along which the track (13) contacts the ground. The track (13) runs over a pair of adjustable idler wheels (12) at the ends of the base of the triangular path. <IMAGE>

Description

SPECIFICATION Improvement in land vehicle propulsion The present invention relates in general to land vehicle propulsion and more particularly to assemblies which can replace a conventional vehicle wheel to convert the normal propulsion to track laying propulsion.

GB patent publication 2101053B describes an assembly of the type with which the present invention is concerned. In the specific form described in this earlier publication the assembly had three idler wheels which serve to guide an endless track around a generally triangular path. In one modification according to the present invention these three idler wheels are replaced by two such wheels which lie at the apices at the base of the triangular configuration. This permits the assembly to be fitted more easily.

In another modification in accordance with the present invention one or each of the two idler wheels has an adjustable rotational axis.

In a preferred embodiment a shaft or spindle supporting each wheel is adapted to receive or fit a key which permits said adjustment by pushing in and rotating. Release of the key locks the shaft into a new location and preferably spring loading on the spindle acts against the pushing of the key and facilitates this selflocking. Notched or toothed slots can engage with polygonal or splined portions of the spindle to locate and lock the spindle in its set position.

In a further modification the endless track is provided with a tread pattern on both sides permitting its reversal. The track can thus be made to have a longer service life by reversing the track once the tread pattern on one side has worn out.

Instead of removing a vehicle wheel and replacing this with an assembly providing the track laying facility in another modification the crown wheel which drives the track is omitted and means is provided to enable the vehicle wheel itself to drive the track. An assembly with a crown wheel and track can also be mounted as an outrigger alongside a vehicle wheel.

The invention in some of the various aspects outlined above may be understood more readily and various other features of the invention may become apparent from consideration of the following description.

An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a schematic side view of an assembly constructed in accordance with the invention; Figure 2 is an end view of the track showing the tread pattern on one side; and Figure 3 is a schematic representation of one of the idler wheels showing the associated adjustment mechanism.

Figure 1 depicts an assembly 30 generally similar to that described in GB 2101053B and like reference numerals that described in GB 2101053B and like reference numerals are used to denote like parts. Instead of using three idler wheels 12 the assembly 30 uses two such wheels 12 at the base of the assembly and these wheels 12 are positionally adjustable in the manner described hereinafter.

The track 13 which is driven by the crown wheel 10 or otherwise has a tread pattern 31 (Fig. 2) on both sides so that the track 13 can be reversed when the pattern 31 on one side has worn.

Figure 3 shows the mounting and adjustment mechanism for one of the guide wheels 12. As shown the wheel 12 is supported by bearings 32 on the spindle 33. The end portions of the spindle 33 are shaped to possess stepped portions 40 with polygonal, e.g. rectangular and circular cross sections which locate in slots 37 in the plates 34, 35, 36. The slots 37 in the plates 34 have notches 39 on both sides, the slots 37 in the plates 35 have notches 39 on one side and a plain surface on the other and the slots 37 in the plates 36 are plain. The notches 39 lock with the polygonal spindle portions as shown and a spring 38 biases the bearings 32 and spindle 33 into the locked position with the spindle 33 located by opposed pairs of notches 39.By engaging the spindle 33 with a key (not shown) and urging the spindle 33 axially against the force of the spring 38 the polygonal portions are released and the spindle 33 is thus freed. Rotation of the spindle 37 in one or other direction will relocate the spindle 33 the spindle 33 into its new location where it becomes locked again. In this manner the rotational axis of the spindle 33 can be adjusted in the directions of arrows A in Figure 1.

1. An assembly for replacing or supplementing a conventional land vehicle wheel; said assembly comprising a rotatable crown wheel or equivalent drive member driven during use, by means of the drive shaft of said vehicle wheel, an endless track driven by the drive member, a pair of idler wheels which constrain the track to run along a generally triangular path centred on the drive member, the idler wheels being disposed at the apices of the base of the triangular path and means for adjusting the position of the rotational axis of at least one of the idler wheels.

2. An assembly according to claim 1, wherein said at least one idler wheel is rotatably supported on a spring-loaded spindle which is adapted to receive a key serving to adjust the position of the spindle.

3. An assembly according to claim 2, wherein end regions of the spindle have circu

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvement in land vehicle propulsion The present invention relates in general to land vehicle propulsion and more particularly to assemblies which can replace a conventional vehicle wheel to convert the normal propulsion to track laying propulsion. GB patent publication 2101053B describes an assembly of the type with which the present invention is concerned. In the specific form described in this earlier publication the assembly had three idler wheels which serve to guide an endless track around a generally triangular path. In one modification according to the present invention these three idler wheels are replaced by two such wheels which lie at the apices at the base of the triangular configuration. This permits the assembly to be fitted more easily. In another modification in accordance with the present invention one or each of the two idler wheels has an adjustable rotational axis. In a preferred embodiment a shaft or spindle supporting each wheel is adapted to receive or fit a key which permits said adjustment by pushing in and rotating. Release of the key locks the shaft into a new location and preferably spring loading on the spindle acts against the pushing of the key and facilitates this selflocking. Notched or toothed slots can engage with polygonal or splined portions of the spindle to locate and lock the spindle in its set position. In a further modification the endless track is provided with a tread pattern on both sides permitting its reversal. The track can thus be made to have a longer service life by reversing the track once the tread pattern on one side has worn out. Instead of removing a vehicle wheel and replacing this with an assembly providing the track laying facility in another modification the crown wheel which drives the track is omitted and means is provided to enable the vehicle wheel itself to drive the track. An assembly with a crown wheel and track can also be mounted as an outrigger alongside a vehicle wheel. The invention in some of the various aspects outlined above may be understood more readily and various other features of the invention may become apparent from consideration of the following description. An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a schematic side view of an assembly constructed in accordance with the invention; Figure 2 is an end view of the track showing the tread pattern on one side; and Figure 3 is a schematic representation of one of the idler wheels showing the associated adjustment mechanism. Figure 1 depicts an assembly 30 generally similar to that described in GB 2101053B and like reference numerals that described in GB 2101053B and like reference numerals are used to denote like parts. Instead of using three idler wheels 12 the assembly 30 uses two such wheels 12 at the base of the assembly and these wheels 12 are positionally adjustable in the manner described hereinafter. The track 13 which is driven by the crown wheel 10 or otherwise has a tread pattern 31 (Fig. 2) on both sides so that the track 13 can be reversed when the pattern 31 on one side has worn. Figure 3 shows the mounting and adjustment mechanism for one of the guide wheels 12. As shown the wheel 12 is supported by bearings 32 on the spindle 33. The end portions of the spindle 33 are shaped to possess stepped portions 40 with polygonal, e.g. rectangular and circular cross sections which locate in slots 37 in the plates 34, 35, 36. The slots 37 in the plates 34 have notches 39 on both sides, the slots 37 in the plates 35 have notches 39 on one side and a plain surface on the other and the slots 37 in the plates 36 are plain. The notches 39 lock with the polygonal spindle portions as shown and a spring 38 biases the bearings 32 and spindle 33 into the locked position with the spindle 33 located by opposed pairs of notches 39.By engaging the spindle 33 with a key (not shown) and urging the spindle 33 axially against the force of the spring 38 the polygonal portions are released and the spindle 33 is thus freed. Rotation of the spindle 37 in one or other direction will relocate the spindle 33 the spindle 33 into its new location where it becomes locked again. In this manner the rotational axis of the spindle 33 can be adjusted in the directions of arrows A in Figure 1. CLAIMS

3. An assembly according to claim 2, wherein end regions of the spindle have circu lar surface portions and polygonal surface portions, the polygonal surface portions locating within shaped slots opposed in support plates to lock the spindle in a set position under the action of the spring force.

4. An assembly according to claim 1, 2 or 3, wherein the track has a tread pattern on both sides enabling it to be reversed after wear has taken place on one side.

5. An assembly according to any one of the preceding claims and mounted as an outrigger alongside said vehicle wheel.

6. An assembly according to any one of claims 1 to 4, wherein means is provided to convert the vehicle wheel itself into the drive member for the track.

7. An assembly substantially as hereinbefore described with reference to, and as illustrated in, any one or more of the accompanying drawings.

8. A land vehicle employing a plurality of assemblies each constituted in accordance with any one of the preceding claims.