AU6283090A - Transport apparatus - Google Patents

Description

TRANSPORT APPARATUS This invention relates to transport apparatus. This invention has particular but not exclusive applicati to wheelchairs for disabled persons and the like, and f illustrative purposes reference will be made to such applicatio However, it is to be understood that this invention could be us in other applications, such as industrial vehicles.

Modern powered wheelchairs are typically constructed traditional hand-propelled designs with motor drive equipme adapted thereto. Such wheelchairs typically have a pair of lar rear wheels, each driven by an individual electric motor a control system and a pair of small castoring front wheel Steering is accomplished by selectively varying the relati speeds of the two rear wheels. Such wheelchairs are qui expensive to build, particularly as two complete drive syste must be provided.

Attempts have been made to reduce the cost of powe wheelchairs by constructing three-wheeled wheelchairs in which single powered wheel pivots to steer the wheelchai Unfortunately, such chairs have proved to have insuffici stability to provide safe transport. A wheeled vehicle w overturn along a line joining any pair of adjacent wheels, and vehicle with a triangular wheel plan has a tendency to overt about a pivot line connecting the swiveling wheel to one of other wheels.

The present invention aims to alleviate the ab disadvantages and to provide transport apparatus which will reliable and efficient in use. Other objects and advantages this invention will hereinafter become apparent. With the foregoing and other objects in view, this invent in one aspect resides broadly in transport apparatus including: a frame assembly; wheeled support means for supporting said frame assembly an operating attitude and including a steerable drive wheel an supporting wheel, and stabilizer means for provide support to said frame assem upon inclination of said frame assembly beyond said operat attitude.

The frame assembly may may take any form consistent with function of mounting the support wheel, the steerable drive wheel and the stabilizer means. In the application to a wheelchair, the frame assembly is preferably integrated into the structure of a wheel chair and may be formed as a rigid structure for maximum strength. Whilst rigidity of structure is a desirable characteristic of the frame assembly, in keeping with most wheel chairs it is preferred that the frame assembly include a first portion to which the drive wheel is mounted and a second portion to which the support wheel is mounted, the first portion being detachably mounted to the second portion such that the transport apparatus may be dismantled for stowage.

Preferably, the apparatus is provided with a single steerable drive wheel mounted to the first portion of the frame assembly and a pair of coaxial support wheels mounted to the second portion of the frame assembly such that the apparatus obtains the advantages of simplicity, economy and efficiency of the the tricycle-type apparatus of the prior art, without the disadvantages of instability inherent in such apparatus.

The steerability of the drive wheel may be provided by any suitable steering means permitting selectable direction of travel of the drive wheel relative to the frame assembly whist permitting the transmission of rotary power to the drive wheel. For example, the steering means may include a tiller bar or a steering wheel, but it is preferred that the steering means include a cranked shaft extending vertically above the drive wheel to a location convenient for a seated passenger to operate. The steering means may include a power actuator such that the drive wheel may be steered by small movements of a control switch, joystick or the like whereby the transport apparatus may be rendered usable by a severely-handicapped passenger.

The drive wheel may be mounted to the frame assembly through suspension means whereby variations in the vertical load applied through the drive wheel may be minimised such that a desired level of traction may be attained on uneven surfaces. Such suspension means may for example provide that the drive wheel is substantially supporting its end of the apparatus thereby removing all load from the stabilizer means. Alternatively the suspension means may cooperatively support the load with the stabilizer means and the support wheels, with the driving wheel maintaining sufficient downward force on the ground to maintain traction. T drive wheel may be of a solid type such as plastic or metal alternatively the drive wheel may be provided with a traction a ride inproving tyre selected from solid rubber, pneumatic semipneumatic types.

Preferably, the drive wheel forms a steerable drive whe assembly with driving means for the wheel and the steering mean The driving means may take any form consistent with its functi of being able to power the wheel whilst permitting steering of t wheel. Accordingly, the driving means may include electric moto or internal combustion engines, with electric motors bei preferred for their suitability for a wide range of operatio including indoor operations. For wheelchair embodiments of t present invention electric motors are particularly preferred fr the point of view of their quietness of operation and safety confined spaces.

The driving means is preferably mounted in the dri assembly such that it steers with the steering drive wheel su that the need for complicated drive linkages such as consta velocity joints is eliminated. Preferably, the drive means driv the steering drive wheel through a speed reducing drive train, t speed reducing drive train preferably including a prima reduction portion and a final drive reduction portio Preferably, the primary reduction portion comprises a belt and a a pair of unequal pitch pulleys, and the final drive reducti portion is a gear train. The gear train preferably compris alternating nylon and mild steel helical cut gears such that t gear train is substantially lubrication free.

The stabilizing means may take any form consistent with t function of preventing the apparatus from overturning about axis drawn between the drive wheel and any support wheel, and such may include skids, wheels or the like. Preferably, a pair stabilizing wheels is provided, the stabilizing wheels bei arranged with the pair of support wheels in a substantially squa or rectangular pattern such that the maximum stability may provided within the length and width of the transport apparatu Of course, if desired, other wheel configurations, including greater number of support wheels and/or stabilizer wheels may used. The preferred pair of stabilizer wheels may be of the castoring or self-steering type such that they may align themselves with the direction of motion of the transport apparatus at any time. Alternatively, the stabilizer wheels may be coupled for steering in concert with the steerable drive wheel. In either case, it is preferred that the drive wheel be mounted to the frame assembly substantially intermediate the stabilizer wheels for maximum maneuverability.

In embodiments of the present invention where the weight of one end the apparatus is borne by the driving wheel on level ground or even slightly uneven ground, it is preferred that the drive wheel and stabilizer wheels be in vertical alignment. Suitably, the stabilizer wheels are arranged to be ten to twenty millimetres and preferably twelve millimetres above a level surface with which the drive wheel is in contact, such that minimal overturning movement of the transport apparatus may occur before one or other of the stabilizer wheels contacts the surface and stabilises the apparatus.

The frame assembly may include a seat for supporting a passenger. For example, the seat may be mounted to the first portion by a vertical stem associated with the seat and adapted to slide within a vertical socket associated with the first portion of the frame assembly, the stem being provided with an outwardly projecting key adapted to cooperate with one or the other of a pair of opposed slots provided in said sleeve, whereby the seat may be selectively aligned longitudinally with the frame assembly. By this means, the seat is provided with anti-rotation security whilst being selectable between a passenger-operated mode with a user facing the drive wheel and a supervisor-operated mode with the passenger facing away from the drive wheel, such that the transport apparatus may be operated as desired by the passenger or by an accompanying supervisor.

The transport apparatus may be provided with attachment means for attaching an accessory to the transport apparatus. Suitably, the accessory is a shopping trolley, and the attachment means includes clamps for attachment to the rear tubular legs of a standard shopping trolley, such that a person sitting in a wheelchair may utilise a shopping trolley for storing purchases, thus obviating the necessity for bringing a purpose-built receptacle to a shopping centre.

In another aspect, this invention resides in a method forming a transport apparatus, including:- providing a frame assembly; providing a drive wheel mounted to a front portion of sai frame assembly by a substantially vertical steering pivot; providing a pair of support wheels mounted to a rear portio of said frame assembly at opposed ends of a transverse axis; providing a pair of stabilizer wheels mounted to said fra assembly through castoring steering pivots, said stabilizer wheel being disposed substantially outboard of said drive wheel; and assembling said frame and said wheels to form said transpor apparatus. In order that this invention may be more easily understoo and put into practical effect, reference will now be made to th accompanying drawings which illustrate a preferred embodiment o the invention, wherein:-

FIG. 1 is a side view of a transport apparatus according t the invention;

FIG. 2 is a plan view of the transport apparatus shown i

FIG. 1 with the seat removed for clarity, and

FIG. 3 is a side view of a further steering apparatus fo the transport apparatus. The transport apparatus 10 shown in FIGS. 1 and 2 includes rear frame 11 and a front frame 12. The rear frame 11 includes vertical central tube 13 which in turn supports a square tube 1 into which a square peg 15 slides. The square peg 15 is mounte to the front of the rear frame 11, and a retaining pin 16 passe through matching apertures in the tube 14 and the peg 15 to retai the former within the latter. A pair of support wheels 17 ar mounted for rotation about a common transverse axis at the rear o the rear frame 12, and a pair of stabilizer wheel supports 2 extend forwardly and outwardly from the central tube 13 to carr stabilizer wheels 21 in castoring wheel carriers 22.

The front frame 11 includes a vertical steering bearing 2 within which a steering frame 24 is supported. A drive wheel 2 carried within the steering frame 24 is powered through reduction drive 26 from an electric motor 27 also mounted to t steering frame 24. The vertical position of the drive wheel 25 relative to the support wheels 17 and the stabilizer wheels 20 is adjusted to leave a clearance of about twelve millimetres between the stabilizer wheels and a flat plane 30 engaging the drive wheel 25 and the support wheels 17. This ensures that, on level ground, all the weight of the front portion of the transport apparatus 10 is applied to the drive wheel 25 to enhance traction, while the transport apparatus 10 cannot rotate more than a small angle about an overturning axis before contact occurs between the ground and an stabilizer wheel 20, preventing further rotation.

A shaped seat shell 31 is mounted on a vertical shaft 32 to form a seat assembly 33. The shaft 32 slides into the central tube 13, and which may be detached therefrom for stowage. A notched plate 34 engages with lugs 35 formed on the upper end of the central tube 13 to lock the seat assembly 33 facing either the front or rear of the transport apparatus 10 as desired. The rear frame 11 includes a support for a battery 36 and an electronic speed control 37, the latter being controlled from a switch assembly 40 mounted to the steering frame 24, the switch assembly 40 being actuated by a flexible cable 41 passing through a steering handle 42 to an actuator 43 on its top end. The steering handle 42 may be detached from the top of the steering frame 24 for stowage.

A brake lever 44 operates an eccentric circular cam 45 to urge a brake plate 46 into engagement with a support wheel 17 to immobilise the transport apparatus 10 as desired. Footrests 47 are mounted to the front and rear frames 11 and 12.

Referring now to FIG. 3, the steering assembly 60 has a steering frame 61 pivoted within a steering pivot 62. A steering motor 63 mounted to the steering pivot through a longitudinal member 64 is connected to rotate the steering frame 61 through reduction gearing 65. Control switches or the like placed within operative reach of a passenger operate the steering motor 63.

It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as defined in the appended Claims.

Claims (18)

1. Transport apparatus including:- a frame assembly; wheeled support means for supporting said frame assembly an operating attitude and including a steerable drive wheel an supporting wheel, and stabilizer means for provide support to said frame assem upon inclination of said frame assembly beyond said operat attitude.

2. Transport apparatus according to Claim 1, wherein said fr assembly includes a first portion to which said drive wheel mounted and a second portion to which said support wheel mounted, said first portion being detachably mounted to s second portion such that said transport apparatus may dismantled.

3. Transport apparatus according to Claim 2, wherein said fr assembly includes a single steerable drive wheel mounted to s first portion of said frame assembly and a pair of latera spaced support wheels mounted to said second portion of said fr assembly.

4. Transport apparatus according to Claim 3, wherein s steerable drive wheel forms part of a drive wheel assem including steering means and drive means for driving said dr wheel.

5. Transport apparatus according to Claim 4, wherein s steering means includes power actuation means such that said dr wheel may be steered by small movements of a remote control.

6. Transport apparatus according to Claim 5, wherein said dr wheel assembly is steered with said drive wheel by said steer means.

7. Transport apparatus according to Claim 6, wherein said dr means includes an electric motor and a speed reducing drive tra said speed reducing drive train including a primary reduction portion and a final drive reduction portion.

8. Transport apparatus according to Claim 7, wherein said primary reduction portion comprises a reduction belt drive and wherein said final drive reduction portion is a gear train.

9. Transport apparatus according to Claim 8, wherein said gear train comprises alternating nylon and mild steel helical cut gears such that said gear train is substantially lubrication free.

10. Transport apparatus according any one of claims 3 to 9, wherein said stabilizer means includes a pair of laterally spaced stabilizing wheels spaced longitudinally from said support wheels.

11. Transport apparatus according to Claim 10, wherein said stabilizer wheels are castoring or self-steering wheels.

12. Transport apparatus according to Claim 10, wherein said stabilizer wheels are coupled for steering in concert with said steerable drive wheel.

13. Transport apparatus according to any one of Claims 10 to 12, wherein said steerable drive wheel is mounted to said frame assembly substantially intermediate said stabilizer wheels.

14. Transport apparatus according to Claim 13, wherein said steerable drive wheel and said stabilizer wheels are disposed with their axes in or adjacent a transverse vertical plane.

15. Transport apparatus according to Claim 14, wherein said stabilizer wheels are maintained above the surface on which said transport apparatus is supported when in said operative attitude.

16. Transport apparatus according to any one of the preceding Claims, wherein said frame assembly includes a seat for supporting a passenger.

17. Transport apparatus according to Claim 16, wherein the seat is mounted to said frame assembly whereby said seat may selectively aligned longitudinally with said frame assembly.

18. A wheelchair including:- a frame assembly supported by a steerable drive wheel and pair of laterally spaced support wheels; a seat for supporting a passenger, and a pair of castoring or self-steering stabilizing wheel wherein said steerable drive wheel is mounted to said fra assembly substantially intermediate said stabilizer wheels, a wherein said stabilizing wheels are located in longitudinal spaced relationship with said pair of support wheels.