GB2199794A

GB2199794A - Continuously variable tri-directional vehicle suspension system

Info

Publication number: GB2199794A
Application number: GB08630666A
Authority: GB
Inventors: Bruce David Peterson
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-23
Filing date: 1986-12-23
Publication date: 1988-07-20
Also published as: GB8630666D0

Abstract

A vehicle suspension has shock-absorbing travel for each wheel in three different directions ie linear as well as rotational about an axis and provides a method for rotating the suspension around the axis on which it is mounted for the purpose of changing suspension attitude and/or vehicle ground clearance and/or vehicle wheelbase length. The arrangement allows the attitude of suspension arms 33, 34 on one side of the vehicle to be disposed at ninety degrees to the suspension arms 31, 32 on the opposite side. This allows level vehicle posture while traversing terrain with considerable slope (typically 30 degrees). <IMAGE>

Description

CONTINUOUSLY VARIABLE TRI-DIRECTIONAL VEHICLE SUSPENSION SYSTEM (CVTDVSS) This invention relates to a motor vehicle suspension.

Motor vehicle suspensions can be divided into two general types according to the direction of their wheel travel when viewed from the side of the vehicle: linear, and rotational around an axis. Figure 1 shows examples of each type. 101 and 102 are linear. 103 is rotational. 104 is rotational perpendicular to the wheel face, but linear when viewed from the side of the vehicle.

Because vehicle suspensions are either rotational or linear, and are quite simple in action, they allow wheel damage when encountering large obstacles at slower speeds, or smaller obstacles at high speeds. Also, since the static position of wheels and suspensions is fixed relative to host vehicles, three and more wheeled vehicles assume the angle of slope of the terrain they are crossing, and are usually limited to low slope-angle terrain. In addition, vehicles are either unstable in high-speed cornering because of fixed high ground clearance, or unsuitable for off-road use because of fixed low ground clearance.

According to the present invention there is provided a tri-directional suspension as shown in Figure 2, which is comprised of a wheel with tire and hub 31-34 that is suspended from the chassis member 15 and drive axis 20 by spring and shock absorbing components that provide resistance to wheel travel in directions 16,17, and 18.

The wheel's position is made continuously variable relative to chassis member 15 and drive axis 20 by means of hydraulic or other powered components connected to both chassis member 15 and driveshaft housing part 25 which force the wheel and its associated spring and shock absorbing components to rotate in directions 16 and 17. While wheels in both the front and back of vehicle 40 will move in directions 16,17, and 18 in response to ground shocks, powered component forced rotation will be in direction 17 only to the dead center point 12 for wheels 31 and 33, and forced rotation in direction 16 will be limited to the dead center point 12 for wheels 32 and 34. Forced rotation in direction 16 will be limited according to minimum ground clearance considerations for 31 and 33, and forced rotation in direction 17 will be similarly restricted for 32 and 34.

In Figure 3 it can be seen that vehicle 40 is level relative to a slope of A degrees (typically 30 degrees) when wheels 31 and 32 are held to the dead center position 12 and wheels 33 and 34 are rotated to position 14 (typically 90 degrees from position 12).

Figure 4 shows that the ground clearance of chassis member 15 and vehicle 40 will lessen to the degree that the wheels 31-34 are rotated away from dead center point 12. Creative use of the CVTDVSS gives vehicle operators a full range of choice when travelling over varied terrain.

A) Rough, broken terrain would suggest maximum ground clearance position and maximum wheel travel.

B) Minimum ground clearance, maximum wheelbase length position would enhance stability and lower profile for high speeds on flat terrain.

C) Differential movement of suspension on each side of the vehicle will allow level vehicle attitude when travelling through hilly or mountainous terrain.

The invention as represented in Figures 5,6,7 and 8 uses motorcycle components which permit an exceptionally large degree of travel along direction 18 of suspension movement, and make a corresponding four wheel drive single person vehicle suitable for use on widely varying terrain including landscape which has sharp drops of several meters.

The rotational suspension unit 50 enables a single street motorcycle rear spring and shock absorber to absorb rotational shock in directions 16 and 17, allowing a typical 10-15 degrees of travel in each direction. Unit 50 components are: 51 linkage arms 52 travel limiter 53 movement activator, attached to 25 Thè part absorbing shock in direction 18 is 60, motocross motorcycle forks (White Power upside down variety).

Figure 7 shows parts 71 and 72 which are plastic bearings allowing rotation between the assemblies on each side of them.

Figure 8 shows the hydraulic mechanism which forces rotation between 15 and 25. It consists of a double-acting hydraulic ram 81 which is attached to both 15 and 25.

The invention can conceivably be scaled up to accomodate earth moving and shaping equipment weighing tens of thousands of kilograms. It is likely that suspension travel relative to vehicle size will be greatly reduced in such large scale applications, and that any of a number of suspension components--such as air bags or large coil springs--be substituted for motorcycle forks and shock absorbers.

The industrial applicability of the invention is thus limited only by the purpose and design of the host vehicle with which the invention is to be used. The invention could be adapted for use with any one, two, three, four, or other wheeled vehicle in existence today.

The particular advantages of the invention suggest off-road use, especially in mountainous areas and in areas where snow, mud, sand, rocks, or shallow water restrict usage of vehicles with conventional suspensions. A brief example of possible invention use in the Agriculture, Recreation, and Defense industries will be given.

Agriculture As suspension for a one meter wide 300 kg four-wheel-drive vehicle with 200-400 kg roof mounted load carrying capacity. The vehicle would have two two or four stroke-cycle engines of 250cc or 500cc capacity and would be designed using techniques of multiple redundancy for maximum reliability. The vehicle could show significant advantages over horses or existing four wheeled vehicles for sheep and cattle ranchers.

Recreation As suspension for a two-passenger, two or four wheel drive vehicle which is a fraction of the weight and size of traditional four-wheel drive vehicles intended for off-road recreational use.

Defense As suspension for a single-person four-wheel-drive vehicle used in logistic or guerilla special-mission situations. The vehicle would weigh less than 300 kg and would be powered by two motocross motorcycle engines. Switchable two or four wheel articulated steering would enable extreme maneuverability, alllowing the CVTDVSS equipped machine to outperform small land-based vehicles previously used.

Claims

1. The combination in one vehicle wheel suspension of linear, uni-directional spring and hydraulic shock absorbing resistance to wheel movement with uni or bi-directional spring and hydraulic shock absorbing resistance to wheel rotation around the axis on which the suspension is mounted.

2. The method of rotating an entire single wheel vehicle suspension around the axis on which it is mounted for the purpose of changing suspension attitude and/or vehicle ground clearance and/or vehicle wheelbase length.

3. A continuously variable tri-directional vehicle suspension system substantially as described herein with reference to Figures 5,6,7 and 8 of the accompanying drawings.