GB2382334A

GB2382334A - Tiltable vehicle

Info

Publication number: GB2382334A
Application number: GB0128242A
Authority: GB
Inventors: Rodney John Davey
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-24
Filing date: 2001-11-24
Publication date: 2003-05-28
Anticipated expiration: 2021-11-24
Also published as: GB0128242D0; GB2382334B

Abstract

A three wheeled car comprises a rigid tiltable assembly containing a driver's cockpit 13 and a tyre 12 which is driven by a power unit contained within rear section 10. The whole assembly is rotatably attached to a conventional front section 15 by rotatable assembly 16. Backwards and forwards movement of foot pedals on device 17, is translated into clockwise or anti-clockwise tilting of the tiltable assembly by rotatable assembly 16 which contains freely rotating bearings, attaches cockpit 13 to front section 15, rotates cockpit 13 in relation to front section 15 and contains a chamber for inter-connection of controls and services. Non-tilting controls are operated from handlebar 18. The tilting action steers the car in the direction of tilt and is self-centering. Tilting is controlled by the hands in alternative embodiments. Various power, transmission, braking and suspension units can be provided in rear section 10.

Description

TILTABLE VEHICLE This invention relates to a three wheeled vehicle, referred to here as a car, which contains a tilting rear wheel and corners at high speed. The vehicle is referred to as a car because it is driven not ridden.

Cars are well known vehicles which comprise three or four wheels attached to a chassis or body which houses at least one person and the controls to drive the vehicle Most cars have motive power sources and there are particular types of cars, referred to here as circuit cars, which are preferably open-topped with one or two seats and which are especially suited to driving on private circuits in competition with other drivers or against the clock Circuit cars negotiate corners at speeds which are greater than those of road-going cars of similar classification and accelerate and brake at rates which are greater than those of road-going cars of similar classification.

Circuit cars are, however, relatively expensive to purchase and maintain with the consequence that they are often used on public roads as well as private circuits with compromise to on-circuit performance. Moreover, few circuit cars are able to take advantage of recent advances in motor cycle design and technology, particularly Otto Cycle engines which rotate at greater than 12000 revolutions per minute and tyres which retain grip with the circuit surface at extreme angles of tilt away from the vertical Furthermore, the circuit-based and kit car industry recognises the lack of

variety in the available types of circuit cars and is currently seeking new initiatives to stimulate interest and commercial activity According to the present invention there IS provided a three wheeled car comprising a tiltable assembly containing a rear wheel fixed in relation to a driver's cockpit with said tiltable assembly rotatably attached to the front section of a car so that the rear wheel and cockpit tilt over as a unit in order to substantially increase the maximum speed at which the car negotiates corners Preferably a circuit car made according to the present invention includes one of a variety of motor cycle options containing the rear wheel, satisfies the brand allegiance of motor cycle owners, takes advantage of the simplicity and reduced cost of one rear wheel instead of two, provides a very small forward-facing aerodynamic profile and, through the application of the contemporary motor cycle design and technology, imitates the excitement and sounds of Grand Prix racing Moreover, a car made according to the present invention exhibits a lower centre of gravity than a motor cycle, due to the replacement of a rider by a dnver who sits very close to the ground and provides a new method, experience and sensation of driving which is a combination of-i) riding a motor cycle, derived from judgement of balance and the degree of tilt needed by the combination of the driver's own body, power unit and rear wheel to negotiate a corner at the fastest speed without the rear tyre sliding, ii) flying an aeroplane, derived from the use of the hands or feet to tilt the whole cockpit in order to control the degree of tilt judged necessary to negotiate

a corner ; and iii) driving a car, derived from the overall control of the vehicle whilst sitting in a cockpit, facing two front wheels which are on the ground, holding the steering and motive control means. Furthermore a car made according to the present invention creates a new business opportunity based on the introduction of motor cycle design, technology and brand identity to a high performance car Although pre-eminently designed for use on private circuits, the car can be approved for use on the public roads by complying with the Single Vehicle Approval (SVA) regulations.

A first specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which.- Figure 1 illustrates the assembly of the sections which comprise the car, Figure 2 shows a side view of the assembled car; Figure 3 shows a plan view of the assembled car ; Figure 4 shows a simplified perspective view which illustrates the operation of a foot operated tilting mechanism; Figure 5 shows a schematic view of the operation of the tilting mechanism when the tiltable assembly is tilted fully anti-clockwise from the driver's view ; Figure 6 shows a schematic view of the operation of the tilting mechanism when the tiltable assembly is upright, Figure 7 shows a schematic view of the operation of the tilting mechanism when the tiltable assembly is tilted fully clockwise from the driver's view,

Figure 8 shows a vertical side-section of the rotating assembly, the attachment between the rotating and non-rotating sections of the car and part of the self-centering mechanism; and Figure 9 shows a simplified view of the underside of the assembled car at the plane of rotation to illustrate the operation of the self-centering mechanism Referring to Figs 1, 2 and 3, the tiltable assembly comprises the rear section of a motor cycle 10, including rear wheel 11 and rear tyre 12, rigidly attached to a driver's cockpit 13 Section 10 is attached to cockpit 13 by inserting a male cylindrical part 38 containing a longitudinal keyway slot into the female cylindrical orifice of the motor cycle steering boss 39 in the direction of arrow 40 The orifice also contains a longitudinal keyway slot located so as to lock part 38 and steering boss 39 together and sections 10 and 13 into line. Parts 38 and 39 are secured together by insertion of the keyway blade into the keyway slots and tightening of retaining collar 41 Further tie bars can be provided between section 10 and cockpit 13 Cockpit 13 contains fuel tank 14 Rear section 10 contains various power, transmission, braking and suspension units. The tiltable assembly is attached to the steerable front section 15 by a rotatable assembly 16. The driver's cockpit 13 contains a foot operated tilting device 17 which rotates the whole tiltable assembly clockwise or anti-clockwise relative to the front section 15 at the cross-section between cockpit 13 and front section 15 The driver's cockpit 13 also contains the driver's controls required for front section 15 and those required for the power and transmission units in rear section 10 In this way, the rear tyre 12, motive system, driver and cockpit 13 act as one unit and tilt clockwise or anti-clockwise whilst the

front wheels remain in contact with the ground More particularly, the driver's controls for the front section 15 are mounted on a motor cycle handlebar arrangement 18 at the driver's end of column 19 providing steering and braking Braking is provided by a brake lever operated by the right hand which applies simultaneous braking to the front and rear wheels. The braking forces to the front wheels are applied through hydraulic piping (34 Fig 8) The driver's controls for the power and transmission units, which are part of motor cycle rear section 10, are also provided on or by the handlebar arrangement 18 These controls include an accelerator twist-grip operated by the right hand, a clutch lever operated by the left hand and gear change actuation of the sequential gearbox, which is part of rear section 10, operated by both hands simultaneously by forwards and backwards rotation of the whole handlebar arrangement about its own horizontal axis in the direction of arrow 53, which connects to the sequential gearbox actuating lever by a push-pull Bowden cable. The road speed, engine speed, gear selection and other indicators from the donor motor cycle are retained and provided within the driver's vision. Alternative control arrangements for the power and transmission units can be provided or deleted depending on the preference of the driver or the type of transmission. More particularly, a twist-grip type gear change or gear change by movement of the left hand handle about a hinge point located at the inner end of the handle can be provided for operation by the left hand or if the gearbox is automatic, a clutch and gear change means is not provided However, in the case of an automatic gearbox, an engage/disengage means will be provided in a convenient location in cockpit 13

Fig 4 shows a simplified view of a mechanism to illustrate how controllable tilting movement is provided by converting backward and forward movement of the driver's feet into rotational movement of the tiltable assembly The mating of the rotating parts of the mechanism is achieved by movement of the front section 15 towards the cockpit 13 in the direction of the arrow 20 (see also Fig 1) The positions which the anchorage pylons 21 and 22 for Bowden cables 26 and 33 take up, when the rotating parts are mated, are shown as 21'and 22'As the driver's left foot moves the pedal 23 forwards in the direction of the arrow 24 the core 25 of the Bowden cable 26 pulls on the lug 27 and the tiltable assembly rotates in the direction of the arrow 28. Pedal 23 is also connected to continuous belt 29 and the movement of the pedal 23 in the direction of the arrow 24 causes the continuous belt 29 to circulate and the pedal 30, which is also connected to continous belt 29 to move in the direction of the arrow 31 Lug 27 is also connected to the core 32 of Bowden cable 33 and thus the movement of the lug 27 in the direction of the arrow 28 pulls core 32, which is connected to pedal 30, In precise sympathy with pedal 30 moving the driver's right foot backwards in the direction of arrow 31 Forwards movement of the driver's right foot reverses the process In practice, a cylindrical surface 54 of radius indicated by arrow 55 is incorporated into the mechanism illustrated in Fig 4 as further schematically illustrated in Figs 5,6 and 7 which show the progressive movement of lug 27 as core 32 pulls the tiltable assembly from full anti-clockwise tilt (see Fig 5) to upright (see Fig 6) to full clockwise tilt (see Fig 7) Cylindrical surface 54 is attached to rotatable backplate 16b, which is an integral part of the rotatable part of rotatable assembly 16 (see Fig 8) and having a radius

indicated by arrow 55 rotates unhindered within the Bowden cable anchorage positions. Cylindrical surface 54 is provided so that cores 25 and 32 wrap over this surface when they pull lug 27 towards Bowden cables 26 and 33 respectively Furthermore, cylindrical surface 54 ensures that cores 25 and 32 remain as set up without experiencing slack or extra tension regardless of the angle of tilt and also ensures that cores 25 and 32 apply leverage to rotatable backplate16b which is essentially constant regardless of the angle of tilt, given a constant force at foot pedals 23 and 30 In this way, backwards and forwards movement of the driver's feet is translated into rotational movement of the tiltable assembly using two integrated continuous mechanical loops which are adjusted to operate without hysteresis and provide smooth control of the direction and degree of tilt A first continuous mechanical loop comprises lug 27 connected to core 25 connected to pedal 23 connected to the front section of continuous belt 29 connected to pedal 30 connected to core 32 connected to lug 27 A second continuous mechanical loop integrated with the first comprises the integrated part, which is the front section of continous belt 29, connected to the rear section of continuous belt 29 The damping action required to limit the rate at which the pedals 23 and 30 can be moved is provided by dashpots which are part of the central mechanism of the return pulleys 49 and 50 By locking the pedals 23 and 30 in various positions, using removable U-shaped retainer 51 placed into holes 52, the tiltable unit can be fixed at various degrees of tilt, including in the upright position for driver access The design constraints applicable to this embodiment, where the movement and forces generated by the driver's feet are applied directly by Bowden cables to the tilting

mechanism, are set by the physical capabilities of a typical driver The range of force that a driver can apply with one foot has been established as 5kg to 30kg over a forwards to backwards extension of the leg of 0 46 metres. In the way that the skills to ride a bicycle, using steering and angle of tilt to keep the cycle stable whilst moving in a straight line or cornering, are learnt by experience, so the direction of steering and angle of tilt of the tiltable assembly to keep a car, according to this invention, stable whilst moving in a straight line or cornering, is learnt by experience In order to assist stability and control of the degree of tilt, a self-centering action (see Fig 9) is provided to return the tiltable assembly to the upright condition at speeds typically less than 15 km/hour and from angles of tilt typically less than 10 degrees However, when the car is cornering at high speed, the forces at work include significant centrifugal forces which tend to rotate the tiltable unit into the upright position. This means that angles of tilt typically greater than 10 degrees will only be experienced when the car is cornering at speed and the skills of the driver are being applied to establish a continuously modulated degree of tilt such that centrifugal and self-centering forces balance the component of the weight tending to tilt the tiltable part to its maximum Spring (42 Fig 9), or an alternative means which can be power assisted and automatically controlled, is selected to increase the selfcentering force as the degree of tilt increases to maintain the tilting force needed by the driver's feet, at speeds less than 15 km/hour over 10 degrees of clockwise or anti-clockwise tilt, at an essentially constant and comfortable level. When the car is stationary, as with a stationary conventional motor cycle, as the degree of tilt increases, the force needed to return it to the upright condition becomes of the order of the weight of the tiltable part and falls outside the range of forces designed for the performance of this embodiment in motion. The maximum distance of

extension by the driver's foot from a mid-point condition has been established as 0 23 metres (being 0 46 metres divided by 2) and is applied to the distance of pull on lug 27 round the cylindrical surface from the position shown in Fig 6 to the position shown in Fig 7. Assuming that this distance of pull provides a maximum rotation of 60 degrees, then the circumference of cylindrical surface 54 equals 0 23 metres x 6 = 1.38 metres, attributing a diameter to the cylindrical surface 54 of 0 44 metres. This dimension provides for the design of the cockpit diameter at arrow 57 (Figs 1, 2, 4,8 and 9) to be 0 5. metres and provides the space for foot operated device (17 Figs 1,3 and 4) and the driver's feet The 0 5 metre dimension at arrow 57 also provides the space for the mechanisms, including 16 and 37, located In front section 15. If the maximum rotation is limited to less than 60 degrees then the diameters of the cylindrical surface 54 and cockpit 13, at component 16b can be greater or the extent of movement of the feet reduced Power assistance can also be applied to change the range of the forces required to control tilting from essentially zero to greater than 30 kg in order to respond to the capability of an individual driver. The required cornering speed is achieved by tilting the tiltable assembly such that the rear tyre (12 Figs 1,2 and 3) performs during cornering as it was designed to perform on the donor motor cycle Moreover, the cornering speed is enhanced by further beneficial effects occurring when the tiltable assembly is tilted over which include the lowering of the centre of gravity of the tiltable assembly and the movement of the centre of gravity of the tiltable assembly towards the centre of rotation.

Tilting movement can be provided by other means including mechanical, electrical,

electronic, hydraulic or pneumatic and can include further power assistance methods to reduce the extent or the effort required by the driver's feet to operate the tilting mechanism (see Fig 4) Rates of acceleration and braking are influenced by use of lightweight but strong metallic or non-metallic, distributed or fibrous, independent or composite materials in the construction of the rear section 10, driver's cockpit 13 and front section 15 The need for driver safety in the event of an accident also influences the selection of materials used in the construction of the car Specific rates of acceleration and braking are determined by selection of motor cycle power and transmission units which are part of rear section 10 and the selection of tyre and braking systems for all three wheels Referring to Fig 8, which (for clarity) shows lug 27 without the connection of cores 25 and 32 of Bowden cables 26 and 33 respectively Access into or out of front section 15 is provided through the centre of rotatable assembly 16 for steering, braking and any other control or service connections, including steering column 19 and hydraulic brake piping 34. The whole of the tiltable assembly which contains the rear tyre (12 Figs 1,2 and 3), motive system, driver and cockpit (13 Figs 1, 2, and 3) is rigidly connected to and supported by rotatable part 16b, which is part of rotatable assembly 16 (see also 16b Fig 4) and which rotates about axis 56 The whole of front section 15, the two wheels of which remain in contact with the ground, is ngidly connected to and supported by the non-rotating part 16a within the rotatable assembly 16 (see also 16a Fig 4). Rotatable assembly 16 contains freely rotating

bearings 35 and 36 located between parts 16a and 16b and is preferably positioned so that the mid-point between bearings 35 and 36 is vertically above the axis of the front wheels in order to prevent a turning moment being applied to assembly 16 in the plane of the drawing. Steering rack 37 is geared so that the degree of tilt turns the front wheels sufficiently to steer round corners of defined curvature at defined speed with little or no correction from the handlebar arrangement (18 Figs 1 and 3) In this way the tilting action also provides the essential movement of the front wheels to steer round a circuit Referring to Fig 9 which (for clarity) shows a simplified view of the under-side of the assembled car around the plane of rotation to illustrate the operation of the selfcentering mechanism. The self-centering action of the tiltable assembly is provided by a tension spring 42 mounted underneath and on the centre-line of front section 15, connected to a post 43 which is located underneath, on the centre-line of and at the front end of cockpit 13 by non-extensible flexible cord 44 When rotatable assembly 13 rotates away from the upright in the direction of arrow 45 or arrow 46, post 43 draws cord 44 round guide pulley 47 or 48 and extends spring 42 thus creating an opposing force which returns the rotatable assembly to the upright position when the forces causing tilting are reduced or removed Because the forces involved in tilting vary with the degree of tilt, spring 42 is selected to maintain the tilting force applied by the driver's feet at an essentially constant and comfortable level An alternative embodiment which minimises weight replaces the tension

spring 42 and cord 44 with a single extensible flexible cord A further alternative embodiment of the self-centering mechanism provides power assistance to maintain the forces required of the driver to control tilting within specified limits or to change the range of these forces from essentially zero to greater than 30 kg in order to respond to the capability of an individual driver A second specific embodiment of a complete car will now be described by reference to the first specific embodiment of a car where the driver's feet operate the tilting mechanism (see Fig 4) and the hands, conventionally, operate the steering mechanism (18 Figs 1 and 3) In this second embodiment, the controls follow an alternative approach appropriate to the control of an aircraft, including where the driver's feet operate the steering mechanism In this second embodiment, refernng to Figs 1 and 3, a part-wheel is mounted on a control column positioned between the driver's legs to the rear of device 17 and pivoted at the floor level By use of power assistance means to increase force levels or extend actuation movement, control arangements are provided :- i) to operate the tilting mechanism by hand by clockwise and anti-clockwise rotation of the part-wheel, ii) to operate any necessary gear change mechanism by hand by backwards and forwards movement of the control column, operating the clutch by a lever on the part-wheel, the accelerator by a twist grip on the part-wheel and the brakes by a lever on the part-wheel, and iii) to operate the steering by backwards and forwards movement of the feet

A third specific embodiment of a complete car will now be described also by reference to the first specific embodiment of a car where the driver's feet operate the tilting mechanism (see Fig 4) and the hands, conventionally, operate the steering mechanism (18 Figs 1 and 3) In this third embodiment, the controls follow very closely an alternative approach appropriate to the control of an aircraft, including where the driver's feet operate the steering mechanism In this third embodiment, refering to Figs 1 and 3, the gearbox in rear section 10 is automatic and a joy-stick is positioned between the driver's legs to the rear of device 17 and pivoted at the floor level By use of power assistance means to increase force levels or extend actuation movement, control arangements are provided. - i) to operate the tilting mechanism by hand by left to right movement of the joy-stick; ii) to operate the accelerator lever and integral brake lever located on the cockpit wall by hand, and iii) to operate the steering by backwards and forwards movement of the feet

Claims

1 A three wheeled car comprising a tiltable assembly containing a rear wheel fixed in relation to a driver's cockpit with said tiltable assembly rotatably attached to the front section of a car so that the rear wheel and cockpit tilt over as a unit in order to substantially increase the maximum speed at which the car negotiates corners.

2 A car as claimed in Claim 1 where the rear wheel is attached to a braking means

3 A car as claimed in any preceding claim where the rear wheel is attached to a suspension means

4 A car as claimed in any preceding claim where the rear wheel is driven by a power and transmission means

5 A car as claimed in any preceding claim where the means of tilting is provided by a continuous mechanical loop containing foot operated pedals connected by Bowden cables to a rotating means in order to tilt the rear wheel clockwise or anti-clockwise in relation to the front wheels

6 A car as claimed in Claim 5 where the rotating means contains a cylindrical surface over which the cores of Bowden cables are guided

7 A car as claimed in any preceding claim where the means of tilting is provided by any mechanical, electrical, electronic, hydraulic, pneumatic or other means or combination of these means

CLAIMS (continued)

8 A car as claimed in any preceding claim where power assistance is used to change the extent of actuation or the level of effort required to operate the means of tilting.

9 A car as claimed in any preceding claim where the tilting means contains a freely rotating assembly connecting the tiltable part to the non-tiltable part

10 A car as claimed in any preceding claim where an access chamber is provided between the tiltable part and non-tiltable part for connections and services.

11 A car as claimed in any preceding claim where self-centering of the tiltable part is provided by a means which applies a centering force when the tiltable part tilts away from the vertical

12 A car as claimed in any preceding claim where the self-centering force is provided by any mechanical, electrical, electronic, hydraulic, pneumatic or other means or combination of these means

13 A car as claimed in any preceding claim where all the controls needed to drive the car, other than tilting controls, are provided on the steering means

14 A car as claimed in any preceding claim where gear change actuation is by movement of one or both hands in a manner which does not disrupt the driver's other control activities.

15 A car as claimed in Claims 1-4, Claims 7-12 and Claim 14 where tilting is controlled by the hands and steering is controlled by the feet

CLAIMS (continued)

16 A car as claimed in any preceding claim where the tilting action also steers the car in the direction of tilt.

17 A car as claimed in any preceding claim which is made from metal, non- metal, distributed or fibrous, independent or composite materials or a combination of these materials 18 A car substantially as herein described and illustrated in the accompanying drawing