GB2487708A

GB2487708A - A powered off road mobility device

Info

Publication number: GB2487708A
Application number: GB1013125.8A
Authority: GB
Inventors: Christopher Nicholas Swift
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-08-04
Filing date: 2010-08-04
Publication date: 2012-08-08
Also published as: GB201013125D0

Abstract

A powered off road mobility device 2 comprises: a chassis 4 supporting a backrest 19 and a seat18; a plurality of rotatably mounted wheels 6, the wheels 6 being rotatably mounted on the chassis 4; a controller comprising steering means 10, the controller being in communication with at least one of said wheels 6; and a motor assembly, comprising a motor 8 for powering the rotation of at least one of the wheels 6, the chassis 4 comprising at least one substantially w-shaped, hollow tube 30, with a first concavity 24, a second concavity 26 and a third concavity 28, wherein the first concavity 24 provides support for the seat 18. The powered off road mobility device 2 may further comprise a suspension system 50 governing the back wheels comprising: an upper link 70 running between the chassis 4 and the motor assembly; a lower link 72, also between the chassis 4 and the motor assembly, and a third, dampener bearing link 76 running between the chassis 4 and intersecting with the lower link 72.

Description

MOBILITY DEVICE

Field of the Invention

The present invention relates to mobility devices, and in particular off-road, powered mobility vehicles, such as powered wheelchairs.

Background

The closest prior art known to the Applicant is his own patent application GB2408245A.

The present application presents new features, improvements and refinements over and above the original application, although it does exist in the same field. *.so. * *

* : * 25 For this reasons, the following general introduction to the art is quoted from GB2408245A.

* There has been some development in the field of wheeled assistive off road mobility S. devices that are designed for particular sporting or leisure activities, some of which have limited ability off road. For instance, there are off road mobility devices whose functionality is modUled by incorporating hand cranked or electrically powered attachment for racing Others in the art have proposed addition of oversized wheels for use on sand, grass, mud and like terrain. All rely either on the user or gravity for motive power or on one or more able bodied assistants and many require the user to have considerable strength and balance, thus limiting their use by the physically less able.

Electrically powered off road mobility devices and pavement vehicles have been found to have limited off road mobility in terms of obstacle crossing, stability and their ability to cross soft surfaces. However, they are generally large and bulky and require extra equipment in the form of vehicle l?fts or trailers to transport them." Amongst other uses, the invention is suitable for all kinds of outdoor recreational mobility and in addition for example, for use by the less mobile, whether this lesser mobility is caused through youth, old age, or by being physically less firm or less able.

The other known art in the field is GB2385839A (SUZUKI) and DE l9933953Al (DAIMLERCHRYSLER).

Summary of the invention

In a first broad, independent aspect, the invention comprises a powered off road mobility device, comprising a chassis supporting a backrest and a seat, a plurality of rotatably mounted wheels, said wheels being rotatably mounted on the chassis, a controller comprising steering means, said controller being in communication with at least one of said wheels, and a motor assembly, comprising a motor, for powering the rotation of at * least one of the wheels, wherein said chassis comprises at least one substantially w-r: 25 shaped, hollow tube, with a first concavity, a second concavity and a third concavity, wherein the first concavity provides support for the seat. ****

* I: : The provision of such a w-shaped tube advantageously follows the essential planes of the body of the user seated within the device; the w-shape, at least in its shallower forms, provides support for back, thighs, calves and feet. By providing support for a seat (which may either be integrally formed as a part of the chassis or alternatively be a separate portion) the frame provides support for the user's body arid a degree of safety too.

In a first subsidiary aspect, the invention comprises a plurality of w-shaped hollow tubes.

The provision of a plurality of tubes provides means for building a framework of such tubes. A hollow tubular construction allows for the saving of weight whilst not sacrificing structural strength to any great degree.

In a second subsidiary aspect, the chassis comprises two principal tubes, each tube being substantially the same length as the other, and each tube being arranged parallel to the other, the two tubes being held in said arrangement by one or more attachments, arranged perpendicularly to said tubes and being fixed to said tubes.

This particularly favoured arrangement of tubing and attachments provides a strong frame with sufficient area to allow for the attachment of various safety features. The provision of independently pivotable front wheels is also particularly favoured in this context -that of a rugged terrain mobility device. It allows for increased manoeuvrability; particularly useful in instances when a part of the device becomes stuck in terrain and the user is required to extricate the device from said hazard. It is one of several features designed to ensure the user I driver has the autonomy and confidence to tackle terrain for which traditional mobility devices are unsuitable.

In a third subsidiary aspect the invention comprises two or more front wheels, each of said °. : wheels having an axle, wherein each of said front wheels may be pivoted in an arc * substantially perpendicular to said axle, and each of said wheels may be pivoted * independently of the others.

*....: 25 * 0 Preferably, the pivoting of each wheel is controlled by a separate part of the control means. * s0* * 0* S. S

* In a fourth subsidiary aspect, the steering means comprises a steering column, which passes between the principal tubes.

In a fifth subsidiary aspect, the steering means comprises a steering column, which is orientated to the side of both of the principal tubes.

The provision of an eccentrically placed steering column allows the user to slide more easily onto the tubular frame and seating, from one side of the device.

In a sixth subsidiary aspect, the invention further comprises a front suspension, wherein said suspension comprises a shock absorber.

The provision of a shock absorber at the front is an advancement over the prior art, and in particular 0B24082450 where shock absorbers were only installed adjacent the back wheels.

In a seventh subsidiary aspect the steering means further comprises a pair of projections, each of which may be rotated about the steering column.

The projections which may be pivoted confer two key advantages. First by allowing rotation into an upright position, the user may get out of the vehicle more easily, and specifically would not be impeded by said steering means, and second by allowing rotation of the projections so that they may be brought down to either side of the user, the projections provide means of protecting the user and retaining him or her within the scat. a. S

In an eighth subsidiary aspect, the pivoting of each front wheel is governed by a single * S....

* wishbone suspension system.

S 25 * S

The single wishbone suspension system is a robust and preferred suspension. 0S55

* In a ninth subsidiary aspect, the rotation of the back wheels of said off road mobility

SSS

device is powered by a single motor only.

In a tenth subsidiary aspect the motor is a transaxie drive system, driving a plurality of wheels arranged along a single axis.

A transaxle drive system advantageously generates a large amount of torque providing a heavy load carrying capacity. Utilising a transaxie drive system also eliminates the use of chains and belts, which are noisy and can slip.

More generally, it is the case that a single motor is more reliable and robust than a plurality or motors, as used in the Applicant's previous application.

In an eleventh subsidiary aspect, the device has a pair of back wheels attached to said motor assembly and further comprises a suspension system governing the back wheels and wherein the device further comprises a suspension system governing each of the back wheels comprising an upper link running between the chassis and the motor assembly, a lower link, also between the chassis and the motor assembly, and a third, dampener bearing link running between the chassis and intersecting with the lower link.

The provision of a "four link" suspension system of this type again provides a typically robust, preferred choice of suspension system, which has not been used in the context of such a device before.

In a twelfth subsidiary aspect, the motor assembly comprises a tubular beam, with an inverted "U" shaped profile.

The u-shaped tubular beam provides a solid yet lightweight means of carrying the motor.

* In a second broad, independent aspect, the invention comprises a powered off road * mobility device, comprising a chassis supporting a backrest and a seat, a plurality of * :° * rotatably mounted wheels, said wheels being rotatably mounted on the chassis, a controller comprising steering means, said controller being in communication with at least one of said wheels, and a motor assembly, comprising a motor for powering the rotation of at least one of the wheels, wherein at least one of the wheels is connected to the motor * assembly, and wherein the device ftirther comprises a suspension system governing the back wheels comprising an upper link running between the chassis and the motor assembly, a lower link, also between the chassis and the motor assembly, and a third, dampener bearing link running between the chassis and intersecting with the lower link.

Advantageously the upper link, when loaded, is substantially horizontal, which is to say that it has an orientation substantially parallel to that of the seat. The orientation of the link serves to militate against the swaying of the seat during acceleration and braking -the ride is therefore advantageously made smoother.

The invention also comprises a chassis substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying text and or drawings.

io The invention also comprises an off road mobility device substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying text and / or drawings.

Brief Description of the Figures

The invention will now be described in detail and illustrated by the Figures, of which: -Figure 1 is a perspective view of a mobility vehicle.

Figure 2 is a side view of the vehicle.

Figure 3 is a top down view of the vehicle.

* ss*** * Figure 4 is a front view of the vehicle.

* . *.. 25 * * Figure 5 is a second perspective view of the vehicle.

Figure 6 is a second top down view of the vehicle. S..

S

Figure lOa to lOd are side sectional views of a portion of the mobility vehicle showing the path of travel of the rear suspension.

Dtai1ed descrj jonof the preferred embodiments At Figure 1 is shown an off road mobility device or wheelchair, indicated generally at 2.

The off road mobility device 2 has been designed for rugged outdoor use, so that it may afford its users access to environments, which might otherwise be denied them. The off road mobility device 2 comprises a chassis 4, a plurality of wheels 6 and a motor assembly 7 comprising a motor 8. It also comprises a control interface 10, wheel pivoting means 12, a further controller 14 and a power source 16 (not shown). In this embodiment the off road mobility device 2 further comprises a seat 18, attached to the chassis 4, but equally seating means could be provided as an integral part of said chassis 4. In any event, seat 18 comprises backrest 19. Optionally seat 18 may also provide strapping means such as a seat belt for securing the user in the off road mobility device 2. Further strapping may be provided at various points along the chassis 4, for example to ensure the legs of the user are held securely to the chassis 4.

Advantageously, the off road mobility device 2 is electrically powered, with the power being stored in power source 16 (not shown). The skilled man is invited to consider other means of powering the off road mobility device 2 At Figure 2 the shape of the chassis 4 of the off road mobility device 2 can be seen to follow the curve of a seated person's body -it is substantially w-shaped, which is to say * :*: the chassis 4 resembles a shallow "w" in side profile. A first substantially vertical portion 22 might double as a back support, or comprise a backrest 19; a first, in use, skyward * * facing concavity 24 might provide a hollow for seating, and can be provided with separate r *25 mounting means for a seat 18; a second, in use, ground-facing concavity 26 follows the bend of the user's knees. Finally, a second in-use skyward facing concavity 28 provides means of resting the feet. The body following shape of chassis 4 serves to provide the *1: : user with comfort and support, and also makes it much easier for the user to get into and *** out of the off road mobility device 2, which is very important if the user is transferring from a wheelchair to an off road mobility device, for example by a sliding transfer. In some embodiments, the seat 18 may be powered, for example by a DV electric linear actuator or by a DC electric rotational actuator to allow the body of the user to be moved into several positions; it is desirable when using the off road mobility device 2 for both the chassis 4 and the user's body to be as near to the ground as possible, because it promotes stability. That said, consideration must be given to the types of terrain the vehicle will come across. The skilled man is invited to experiment to find the optimal trade-off between the two in a given set of circumstances. The seat 18 can also be moved into a position aiding ingress and egress.

Figure 3 shows the chassis 4 to be made of two principal tubes 30. Each of said principal tubes 30 runs along a path substantially parallel to the other said tube 30. The principal tubes 30 are hollow, which saves weight. Advantageously in this embodiment the said principal tubes 30 have blocked ends 32. The blocked ends will add to the sturdiness of said principal tubes 30, by stopping the ingress of foreign matter into the tubes 30. In certain embodiments, light may be added to said blocked ends 32. There are a variety of components attached to the principal tubes 30 either directly or via the attachments 34, which serve not only as mounting means for the aforementioned other items but also to bind the two principal tubes 30 together. In other embodiments more than two principal tubes 30 may be utilised. In this embodiment the principal tubes 30 comprise a plurality of connecting portions (30a, 30b, 30c, and 30d), which advantageously allow easy disassembly of the device for transport or storage. It is understood that in the alternative single piece moulded, extruded, or stamped tube construction may be utilised. Different embodiments with a single or more than two principal tubes 30 are possible.

. .: Returning to Figure 1, the wheels 6, of which there are four, are arranged into two pairs; a pair of front wheels 36 and a pair of back wheels 38. The back wheels 38 are larger than V the front wheels 36. The wheels 6 are of similar construction to bicycle wheels, each having a central hub 40, a plurality of spokes 42 (not shown), which support a tyre-bearing outer 44. The front wheels 36 are attached to chassis 4 via attachment 34 and * .. : front suspension 46. The front suspension 46 is a single wishbone suspension, which is advantageously more reliable in this context than the dual wishbone version, and also allows for the device 2 to be positioned nearer to the ground -there is no second wishbone beneath the axis of either of the front wheels 36 which requires additional clearance in order to be housed -the single wishbone part 46 is positioned above the axis of the front wheel 36. Each of the front wheels 36 is pivotable via wheel pivoting means 12 independently of the other front wheel 36. The pivoting of each of the front wheels 36 is effected by the user's manipulation of control interface 10, which is attached to wheel pivoting means 12. The pivoting of the front wheel 36 at figure 3, a]ong with the tapering of the frame 4, as the two principal tubes 30 of the said frame 4 converge. The combination of these features allows for a wheelchair, represented in figure 3 as a block, to approach the device 2, facilitating a slide transfer by allowing for such a close contact.

In contrast the back wheels 38 are not user pivotable. Back wheels 38 are powered by motor 8 which in this preferred embodiment is a transaxle drive motor. The motor 8 rotates the back wheels 38 about axis 48, which is connected to hubs 40 of said wheels 38.

Braking means may interface with the front wheels 36, the back wheels 38 or with both.

The relationship between back wheels 38 and chassis 4 is mediated by back suspension 50, which in this preferred embodiment is a four-link suspension system. Back suspension 50 may be hydraulic, or alternatively comprise a spring and damper system. The motor 8 is attached to chassis 4 via an inverted u-shaped tube 52. Other shapes of tube may be used.

In preferred embodiments, the back suspension 50 connected to back wheel 36 is of the four link type. The detail of the back suspension 50 is best viewed at figure 1 Oa -I Od.

The back suspension 50 comprises upper link 70, which connects frame 4 and inverted U :0..' shaped tube 52. A lower link 72 also connects frame 4 and u-shaped tube 52. A dampener 76 is attached to substantially the mid point of the top 78 of the lower link 72, and also 4:.*.

finds a point of attachment on or adjacent frame 4. The figures 1 Oa shows the length of :: 25 the "wheelbase" of the device 2 extended as the dampener 78 extends. This advantageously allows the device 2 to cope with difficult terrain. Each of back wheels 36 is governed by a separate upper link 70, lower link 72 and dampener 78. :1.

At figure 4, it is shown that the control interface 10 comprises steering means, consisting of a central steering column 60, to which an elongate perpendicular portion 62 is attached.

From each end socket 64 of the elongate perpendicular portion 62 projects a C shaped handlebar 66. The handlebars 66 can be rotated, independently of one another, inside the socket 64; in particular preferred embodiments, the rotation of handlebars 66 is governed by a releasable ratchet mechanism which allows for the discretionary adjustment of handlebar 66 position. In other preferred embodiments, the handlebars will have just two, essential positions, the first "upright" position, as shown in figure 1, and the second "operating" position, in which the handlebars 66 are rotated down in an are towards the user. In this second position, the handlebars 66 also provide an additional means of securing the user in the in the device 2.

Individual controls for controlling the brakes, gearing and other controls are mounted on handlebars 66. In particularly preferred embodiments, all controls will be mounted on the handlebars 66. This is important because it will often be the case that the user is unable to operate a foot pedal.

Figure 4 also shows the off road mobility device 2 shielded by plate 54, which advantageously provides protection to the suspension 46. Optionally lights may be mounted to this plate 54.

Figure 1 also shows controller means 14, which are situated adjacent the underside 58 of chassis 4, next to power source 16. Controller means 14 in this embodiment comprises a sturdy box, and its situation, along with power source 16, adjacent said underside 58, serves to lower the centre of gravity of the off road mobility device 2. Advantageously, both power source 16 and controller 14 can rest on a single shelf (not shown).

* S. 555 * Figure lOb shows the device 2 at 30% extension -that is to say the under conditions of "25 wherein said device 2 is loaded with the weight of a person. The upper link 70 under these conditions remains substantially horizontal, or substantially parallel to the seat 18. As * * such the seat 18 (not shown) is protected from climbing and diving during acceleration and braking, allowing for a smoother ride.

S

Claims

CLAIMS1. A powered off road mobility device, comprising a chassis carrying a backrest and a seat, a plurality of rotatably mounted wheels, a controller comprising steering means, said controller being in communication with at least one of said wheels, and a motor assembly, comprising a motor for powering the rotation of at least one of the wheels, said mobility device further comprising one or more of the following features: a) rear wheels mounted on an axle and a suspension arrangement provided between the chassis and the rear wheel axle; wherein the rear wheels are offset rearwardly by said suspension arrangement to allow improved side access to the seat; b) a suspension system governing the back wheels comprising an upper link running between the chassis and the motor assembly, a lower link, also between the chassis and the motor assembly, and a third, dampener bearing link running between the chassis and intersecting with the lower link; *:* . c) said chassis comprises at least one substantially w-shaped, hollow tube.

* ** * 0 * *
2. An off road mobility device according to claim I, wherein the chassis comprises a * .e* S. * plurality of w-shaped hollow tubes.
3. An off road mobility device according to claim 1 or claim 2, wherein the chassis *:. comprises two principal tubes, each tube being substantially the same length as the other, and each tube being arranged parallel to the other, the two tubes being held in said arrangement by one or more attachments, arranged perpendicularly to said tubes and being fixed to said tubes.
4. An off road mobility device according to any of the preceding claims with two or more front wheels, each of said wheels having an axle, wherein each of said front wheels may be pivoted in an arc substantially perpendicular to said axle, and each of said wheels may be pivoted independently of the others.
5. An off road mobility device according to claim 4, wherein the pivoting of each wheel is controlled by a separate part of the control means.
6. An off road mobility device according to any of claims 3-5, wherein the steering means comprises a steering column, which passes between the principal tubes
7. An off road mobility device according to any of claims 3-5, wherein the steering means comprises a steering column, which is orientated to the side of both of the principal is tubes.
8. An off road mobility device according to any of the preceding claims, further comprising a front suspension, wherein said suspension comprises a shock absorber.
9. An off road mobility device according to any of the preceding claims wherein the steering means further comprises a pair of projections, each of which may be rotated * : about the steering column.0*0*s0 *
10. An off road mobility device according to any of the preceding claims wherein the *25 pivoting of each front wheel is governed by a single wishbone suspension system.
11. An off road mobility device according to any of the preceding claims wherein the *001 * : rotation of the back wheels of said off road mobility device is powered by a single motor *** * only.
12. An off road mobility device according to any of the preceding claims wherein the motor is a transaxie drive system, driving a plurality of wheels arranged along a single axis.
13. An off road mobility device according to any of the preceding claims, wherein the device has a pair of back wheels attached to said motor assembly and further comprises a suspension system governing the back wheels and wherein the device further comprises a suspension system governing each of the back wheels comprising an upper link running between the chassis and the motor assembly, a lower link, also between the chassis and the motor assembly, and a third, dampener bearing link running between the chassis and intersecting with the lower link.
14. An off road mobility device according to any of the preceding claims, wherein the motor assembly comprises a tubular beam, with an inverted "U" shaped profile.
15. A chassis substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying text and or drawings.
16. A off road mobility device substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying text and / or drawings. S. * * SS * **SS..... -* * * *** tS * * I...S S S *. SS S..