WO2009059099A2

WO2009059099A2 - Lockable tilt system for a three-wheeled vehicle

Info

Publication number: WO2009059099A2
Application number: PCT/US2008/081946
Authority: WO
Inventors: Peter S. Hughes; Andrew H. Twombly; Craig Bliss; James D. Baldwin
Original assignee: Vectrix Corporation
Priority date: 2007-10-31
Filing date: 2008-10-31
Publication date: 2009-05-07
Also published as: WO2009059099A3

Abstract

A preferred embodiment of the present invention relates to a vehicle tilting unit. The vehicle tilting unit preferably includes an attachment member configured for releasably mounting to a vehicle body in supporting association therewith. The vehicle tilting unit further includes first and second wheels supports disposed respectively at different lateral positions with respect to a longitudinal axis and configured for mounting vehicle wheels thereto. Further, the vehicle tilting unit includes a tilt mechanism connected to support the attachment member from the wheel supports and allow the wheel supports to move vertically in opposite directions with respect to the attachment member to allow the attachment member and body to tilt with respect to a surface on which the vehicle wheels are disposed.

Description

LOCKABLE TILT SYSTEM FOR A THREE-WHEELED VEHICLE

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. Patent Application Serial No. 60/984,337, filed October 31, 2007 the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to a tilt mechanism for a vehicle.

BACKGROUND OF THE INVENTION

Three-wheeled vehicles are known having one driving rear wheel and two steering front wheels. For example, European Patent No. EPl 180476 Bl describes a laterally tilting three-wheeled vehicle having two steering front wheels. This vehicle has improved roadholding capabilities to keep the resulting force on center of gravity pointed between the wheels to reduce or prevent rollover.

Three-wheeled vehicles having tilt mechanisms with tilt-limiting capability are further known. For example, International Patent Application Pub. No. WO 02/068228 provides a tilting mechanism for a three-wheeled vehicle that uses hydraulic cylinders for limiting the tilting of the vehicle. International Patent Application No. WO 01/36253 Al discloses balancing means for a three-wheeled vehicle that also incorporates hydraulic cylinders with a locking function. Neither reference, however, discloses a method to adjust tiltmg, should the vehicle be locked in a tilted position. Additionally, U.S. Patent No. 5,762,351 discloses a tilt mechanism for a three-wheeled vehicle that may be locked by user- actuated tilting of the handlebars or by actuation of a lever or other mechanical control. The tilt control taught is dependent on the user to control the handlebar movement.

There remains, however, a need to improve the performance and manufacturing of tilt mechanism control.

SUMMARY OF THE INVENTION

A preferred embodiment of the present invention relates to a vehicle tilting unit. The vehicle tilting unit preferably includes an attachment member configured for releasably mounting to a vehicle body in supporting association therewith. The vehicle tilting unit further includes first and second wheels supports disposed respectively at different lateral positions with respect to a longitudinal axis and configured for mounting vehicle wheels thereto. Further, the vehicle tilting unit includes a tilt mechanism connected to support the attachment member from the wheel supports and to allow the wheel supports to move vertically in opposite directions with respect to the attachment member to allow the attachment member and body to tilt with respect to a surface on which the vehicle wheels are disposed.

Preferably, the vehicle tilting assembly further comprises a steering mechanism that includes a steering column rotatably associated with the vehicle body and a turning mechanism connected to the steering column and having a pair of steering rods attached to the tilt mechanism Preferably, turning of the steering column results in turning of the first and second wheel supports. The tilt mechanism preferably includes a central support disposed along the longitudinal axis, a first linkage connecting the first wheel support to the central support, and a second linkage connecting the second wheel support to the central support. A shock-absorbing member is preferably disposed between the first and second linkages. Further, the tilt mechanism preferably includes a tilt-limiting mechanism with a first tilt-limiting member affixed to the first linkage, a second tilt-limiting member affixed to the second linkage, and a caliper affixed to the central support, the caliper being configured to engage tilt-limiting members and to hold the first and second tilt-limiting members in a substantially fixed position relative to the central support.

In a preferred embodiment the vehicle support assembly is included in a vehicle that further includes a vehicle body releasably attached to the attachment member and supported by front wheels that are mounted to the wheel supports and by a rear wheel and for supporting a rider substantially between the front and rear wheels. The vehicle body is preferably configured for substituting the vehicle support assembly with a front fork that includes a single steerable wheel.

An embodiment of the vehicle support assembly can include a first linkage and a second linkage, each extending laterally from the central support on opposite sides of the longitudinal axis. Each of the first linkage and second linkage preferably includes a top suspension arm having an inside end that is pivotably mounted to the central support at the top pivot axis, a bottom suspension arm having an inside end that is pivotably mounted to the central support at the bottom pivot axis, a generally upright strut having a universally pivotable connection with outer ends of both the top and bottom suspension arms, and first and second wheels supportmgly mounted from each of the upright struts A shock absorber pieferably connects the first and second linkages without connection to the central portion The suspension arms and upright struts are preferably substantially rigid and, when subjected to dynamic loading, the universal associations between the bottom suspension arms and the upright struts permit deflections of the upright struts due to the dynamic loading A preferred embodiment of a vehicle includes a vehicle tilting assembly according to previous embodiments that preferably further includes a tilt-lock mechanism operatively associated with the tilt mechanism and selectively placeable in a locked condition to limit the tilting of the vehicle body At least one sensor is preferably included and configured for sensing a parameter relating to the configuration of the tilt mechanism The vehicle preferably further includes a control system associated with the sensor and configured to control an amount of power supplied to a motor of the vehicle based on the parameter sensed by the sensor The sensor can be configured for sensing an angle of steering by which the first and second tilting wheels are steered with respect to the vehicle body, and the controller can be configured to limit acceleration of the vehicle by limiting the amount of power supplied to the motor, depending on the sensed steeπng angle The vehicle can further include at least one sensor configured for sensing whether the tilt-lock mechanism is activated to lock the tilting of the vehicle body, and the controller can be further configured for limiting the acceleration of the vehicle by limiting the amount of power supplied to the motor when the sensor senses that the tilt-lock mechanism is locked Additionally or alternatively, the vehicle can include a sensor configured to sense the speed of the vehicle In this embodiment, the control system associated with the sensor is configured for releasing the tilt-lock mechanism from the locked state when the sensed speed climbs above a predetermined threshold speed value The control system can include a user-input that can be manually activated by the rider for causing the controller to maintain the tilt-lock in the locked state when the detected speed rises above the speed threshold The control system can further include a sensor configured for sensing the angle through which the tilting wheels are turned Additionally, the control system can be configured to override the user-selected lock of the tilt- lock mechanism if the speed of the vehicle is above a higher speed threshold and the angle of the tilting wheels exceeds a predetermined threshold angle

Alternatively the control system is associated with a sensor configured for sensing the acceleration of the vehicle, and the control system is configured for limiting a turning angle of the tilting wheels The control system can be further configured to control an actuator configured to block movement of the steering mechanism of the vehicle in order to limit the turning angle of the tilting wheels

BRIEF DESCRIPTION OF THE DRAWINGS Fig 1 is a front view of a tilt mechanism constructed according to an embodiment of the present invention,

Fig 2 is a front perspective view of a scooter assembly of the embodiment of Fig 1,

Fig 3 is a front-right perspective view of the tilt mechanism of Fig 1, having one wheel removed for clarity,

Fig 4 is a rear-left perspective view thereof, having another wheel removed for clarity,

Fig 5 is a bottom elevation view thereof with both wheels removed for clarity,

Fig 6 is a cross-section right-side view of the tilt mechanism of Fig 1, having both wheels thereof removed,

Fig 7 is a cross-section right-side view of a tilt-adjustmg mechanism of Fig 1,

Fig 8 is a front perspective view of a tilt-adjustmg mechanism of this embodiment,

Fig 9 is a top view of the tilt mechanism of Fig 1, with portions thereof removed to expose internal features,

Fig 10 is a side cut-away view showing the tilt mechanism thereof,

Figs 1 Ia-I Ic are front elevation views of the tilt mechanism of Fig 1 in successive steps of tilting and righting actions thereof, and

Fig 12 is a block diagram showing various electronic components associated with the scooter shown in Fig 2 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, there is show in Fig. 1 a tilt mechanism 31 for a vehicle. Tilt mechanism 31 generally provides a support assembly that is configured to provide tilting attachment for right and left wheels 21A.21B to the body of a vehicle. In an exemplary embodiment shown in Fig. 2, tilt mechanism 31 is affixed to a vehicle body 2, which in this embodiment is for a scooter configured for supporting one or two riders between front and rear wheels. The preferred scooter is powered by a motor for powering at least one of the wheels, and most preferably a rear wheel 10, thereby causing the scooter to move. In alternative embodiments, the vehicle is a motorcycle, in which the vehicle is configured to hold a rider in an upright position, as opposed to the seated position of a scooter, above the motor. In a further alternative, the vehicle is a commuter car, in which the rider is in a seated position, and the vehicle is preferably controlled using pedals and a steering wheel. Additionally, a commuter car may include a roof, doors and a windshield.

Tilt mechanism 31 is preferably mounted onto vehicle body 2 so as to replace the single, front, steerable wheel that would otherwise be mounted, for example, solely to the steering tube IA of vehicle frame 1. The preferred three-wheeled vehicle 31 has two idle front steering wheels 21A,21B and a driven rear wheel 10. The tilt-mechanism 31 is provided for connecting wheels 21A,21B to the frame 1 of the scooter.

Vehicle body 2 of Fig. 2 also has a frame 1 , which can be, for example, that which is described in U.S. Patent No. 6,047,786. Tilt-mechanism 31 , which is preferably attached to frame 1, allows frame 1 and wheels 21A,21B to tilt laterally, and also allows wheels 21 A,21B move vertically, while staying generally aligned with frame 1. Frame 1 of vehicle body 2 preferably includes at the front steering tube IA, in which steering column 3 is rotatably received. One end of steering column 3 is preferably fitted with handlebar 5. Steering axis S-S of steering tube IA preferably lies in the longitudinal plane of vehicle body 2. Vehicle body 2 preferably also includes a seat on which the rider sits, and foot rests 14 on either side thereof. The rear drive- wheel 10 is attached to frame 1 by swing arm 12, which may also house a motor adjacent rear drive-wheel 10. In a preferred embodiment, vehicle 30 is in the form of an electric scooter that includes electric- or hybrid-powered components and systems. Alternatively, vehicle 31 may include a gasoline- or alternative-fuel-powered motor, or may be human-powered, such as by pedals or the like.

In a preferred embodiment, tilt mechanism 31 enables vehicle body 2, steering axis S-S, and wheels 21 A,21B of the vehicle 30 to tilt laterally to either side with respect to the road or surface 28 as vehicle 30 is steered about a curve Advantageously, roadholding of vehicle 30 in curves is improved using tilt mechanism 31 Tilt mechanism 31 also advantageously makes it possible for each wheel 21 A,21B to independently or simultaneously move vertically, preferably in opposite directions from each other, with respect to frame 1 of vehicle 30 Generally, the tilting of wheels 21A,21B is free and substantially unrestricted in order to give substantially the feelmg of a vehicle with a single front-wheel

Tilt mechanism 31 preferably includes suspension assembly 29 to further provide suspension for vehicle 31 over wheels 21A,21B Preferably suspension assembly 29 is a single viscoelastic unit that is connected between wheels 21A,21B such that it does not interfere with the tilting of vehicle body 2 Vehicle 31 may also include a tilt-hmitmg mechanism included in tilt mechanism 31 Preferably, the tilt-limiting mechanism is configured to limit the tilting of vehicle body 2, and more preferably allows for locking of wheels 21A,21B relative to vehicle body 2, which, thus, locks the tilting of vehicle body 2 The tilt-limiting mechanism may improve the stability of the vehicle and may further be used to right vehicle 30, moving it from a tilted position to a substantially upright one or to drive the vehicle to an appropriate lean angle based on apparent gravity, such as a lean angle where the resulting force on the center of gravity is pointed between wheels 21A,21B

In an alternative embodiment a vehicle similar to that shown in Fig 2 may include a tilt mechanism integrally formed with a frame that is part of the vehicle body

Additionally, a scooter can be fitted with a support assembly that is similar to that shown in Fig 1 , but is adapted to replace the rear wheel of a scooter, or a scooter can be fitted with two support assemblies such that the vehicle includes four tilting-wheels Such arrangements are generally described in International Patent Application No PCT/US2007/067389, which is incorporated by reference herein in its entirety

As shown in Figs 1-6, tilt mechanism 31 preferably includes central support 7 that is affixed to vehicle frame 1 m at least one location 32, but preferably between one and four spaced apart locations 32 and most preferably at least three locations 32 The number of attachment locations 32 and the spacing therebetween should be enough to provide a stable, robust connection of tilt mechanism 31 to vehicle body 2 during use In the embodiment shown m Fig 2, central support 7 is affixed to vehicle frame 1 in four locations 32A,32B,32C,32D Two of the locations 32A,32B are located along the lower portion of vehicle frame 1 at opposite lateral sides thereof, and the remaining two locations 32C,32D are spaced vertically between the lower end of the vehicle frame 1 and the upper end thereof, where steering tube IA is located Extension bracket 9 is affixed to the lower end of central support 7 at a single location and splits into a Y-shape to affix central support 7 to the lower end of vehicle frame 1 Extension bracket 9 can vary m size and shape depending on the configuration of vehicle frame 1 such that tilt mechanism 31 can be attached to a variety of vehicle frames without substantial alteration Preferably, extension bracket 9 is adapted to be bolted to vehicle frame 2 and includes two end tabs 33 that slide into openings 34 in vehicle frame 1 and are affixed m place using bolts 35 or other fasteners such as rivets or the like Additionally or alternatively, the ends of extension bracket 9 that affix to vehicle frame 1 can be configured so as to slide into, or otherwise engage, a portion of vehicle frame 1 and can include holes to use m bolting the extension bracket 9 onto vehicle frame 2 Posts 6A,6B are affixed to the upper end of central support 7 and extend therefrom to affix to vehicle frame 2 to provide further support for tilt assembly 31 Preferably, posts 6A,6B are configured to be removably fastened, such as by bolting, so that tilting mechanism 31 can be removable or replaceable by fastening to the front of vehicle body 2 Alternatively, tilting mechanism 31 can be permanently affixed to body 2, such as by welding to vehicle frame 1, but preferably tilt mechanism 31 is not welded to vehicle body

Central support 7 is provided with hinges for respective pairs of upper suspension arms 11A,1 IB and lower suspension arms 13A,13B Suspension assembly 29 is preferably linked to two opposite suspension arms, for example, to upper suspension arms 1 IA, 1 IB or to lower suspension arms 13A,13B This enables a single suspension system, comprising for example a spπng/shock absorber assembly 29, to provide for the elastic suspension of both front steering wheels 21A,21B and prevents or substantially reduces the tilting of the wheels 21 A,21B with respect to the vehicle body 2 or frame 1 during vertical movement of wheels 21A,21B In an alternative embodiment, an independent suspension system can be provided, such as with shock absorbers or springs attached to each wheel and to the axle or suspension arm connecting the wheels The use of a single suspension assembly 29 between suspension arms 1 IA₅I IB, however, may reduce the influence of the suspension system with tilting of vehicle 30, compared to the use of an independent suspension associated with each wheel 21 A,2 IB

Suspension arms 11A,11B,13A,13B of each of said pairs are preferably disposed substantially symmetrically on opposite sides relative to the longitudinal axis or plane of vehicle body 2, with upper suspension arms 11A,1 IB being pivoted about a common axis V-V and lower suspension arms 13A,13B being pivoted about a common axis W-W As shown in Fig 6, pivot axes V-V₅W-W of the respective suspension arms 11A,1 IB or 13 A, 13B are preferably longitudinally aligned with each other and vehicle body 2 Further preferably, pivot axes V-V₅W-W lie in the longitudinal plane of vehicle body 2 and are preferably substantially parallel to one another Each upper suspension arm 1 IA, 1 IB and lower suspension arm 13A,13B is articulated at the lateral ends thereof from the pivot axes V-V₅W-W by respective joints on corresponding upper and lower ends of respective uprights 17A,17B In this manner, each corresponding pair of upper arms 1 IA₅I IB and lower arms 13A,13B, along with the respective upright 17A,17B, forms an articulated, four-bar linkage 70A,70B extending laterally from central support 7 Various types of joints are possible for use m articulating suspension arms

11A,11B,13A,13B with uprights 17A,17B It is preferred, however, that the selected joints permit articulation of suspension arms 11A,11B,13A,13C on the uprights 17A,17B along at least two axes Specifically, the joints should allow for rotation of uprights 17A,17B along axis M-M and along a second axis that is orthogonal to axis M-M to allow for vertical movement of uprights 17 A₅17B by rotation of the respective upper 11 A₅11 B and lower

13A.13B suspension arms In a preferred embodiment, the joints allow for universal rotation of the uprights 17A,17B with respect to one or both of the corresponding suspension arms 11 A, 11 B, 13 A, 13B This may be carried out by configuring the joint with rotation along a third axis that is orthogonal the first two axes of rotation Such an arrangement provides three rotational axes between suspension arms 11A,11B,13A,13B and the respective uprights 17A.17B

In order to achieve the preferred degrees of freedom between the suspension arms 11A,11B,13A,13B and the uprights 17A,17B the associated joints can be in the form of ball-and-socket joints 15A,15B, which are shown as connecting the lateral ends of upper suspension arms 1 IA, 1 IB to the upper ends of the respective uprights 17A,17B Shown m detail in Figs 7 and 8 universal joints 18A,18B are preferably used to connect the lateral ends of lower suspension arms 13A,13B to the lower ends of uprights 17A,17B Preferably, universal joints 18A,18B are rotatably affixed to the lateral ends of lower suspension arms 13A,13B, which may be carried out according to the arrangement shown in Fig 9, wherein the universal joint 18A includes a pivot shaft 36 extending from clevis 38 and inserted into matching pivot opening 37 m the lateral end of lower suspension arm 13A In alternative embodiments both sets of joints 15A,15B,18A,18B may be ball-and socket type joints, or both may be rotating universal joints In a further alternative embodiment, joints 18A, 18B may be ball-and-socket joints and joints 15A,15B may be rotating universal joints The additional degree of freedom for uprights 17A,17B provided by rotatably affixing uprights 17A,17B to suspension arms 11A,11B,13A,13B protects the mechanism from jamming and from damage due to fatigue during repeated dynamic loading of the tilt mechanism 31 caused by movement of the vehicle 30. For example, universal joints 18A,18B may rotate about the lateral axis of lower suspension arms 13A,13B during regular movement thereof. Such rotation is caused by dynamic loading that would otherwise be absorbed, for example, through a combination of torque applied to suspension arm 18A,18B or a bending moment applied to upright 17A,17B, which although rigid, may compress during dynamic loading causing them to tilt on a lateral axis. Accordingly, joints 15A,15B and 18 A, 18B are preferably structured to provide corresponding rotation of uprights 17A, 17B in a lateral plane of at least 2° and more preferably at least 4° and further preferably up to about 5°. Additionally, dynamic loading on tilt mechanism 31 may cause deflection of one or more parts thereof, such as arms 11 A,l 1B,13A,13B in one or more directions.

As shown in Fig. 6, axis V-V and axis W-W are preferably parallel to each other and are further preferably angled with respect to surface 28, upon which vehicle 30 is designed to rest, at an angle 16 that is preferably at least about 0°. Angle 16 is preferably less than 30° and is more preferably between about 5° and 20°. In a preferred embodiment, angle 16 is about 10°. Further, axis MA-MA and axis MB-MB, which join the respective upper joints 15A,15B and lower joints 18A,18B of each upright 17A,17B, are preferably oriented with respect to axes V-V₅W-W so as to be inclined backwards, forming an angle 26 through a plane parallel to the longitudinal plane of the vehicle body 31. Angle 26 is preferably at least 90° and is further preferably less than about 120°. In a preferred embodiment angle 26 is between about 100° and 105°. Angle 26 is preferably about 102°. To achieve the desired value for angle 26, suspension arms 11 A,l 1B,13A,13B, as well as center support 7 are preferably formed such that joints 15A,15B are positioned aft of joints 18A,18B, as shown in Fig. 6.

Ball joint 15 A, 15B of each upper suspension arm 11 A, 11 B is preferably set apart from pivot axes V-V of said arm by a distance 40 that is preferably parallel to the analogous distance 41 of the corresponding lower arm 13A,13B. The distance 40 may be equal to or less than distance 41 and is selected in order to provide a desired balance between handling and stability, as would be understood by those having ordinary skill in the art. Each upright 17A,17B holds thereon a wheel support 19A,19B that may be in the form of a conventional bearing/axle assembly. The wheel supports 19A,19B each pivotably secure respective front wheels 21A,21B to vehicle 30 so as to revolve about a respective horizontal axis ZA-ZA₅ZB-ZB. In a preferred embodiment, disk-brake mechanisms 24A.24B are further affixed to uprights 17A,17B between wheel supports 19A,19B and wheels 21 A,21B.

Furthermore, each of the axes MA-MA₁MB-MB that passes through the upper and lower joints 15A,15B and 18A,18B of the respective uprights 17A,17B of each wheel 21A,21B defines the steering axis of each wheel 21A,21B. Axes MA-MA,MB-MB may be contained in the median/longitudinal-vertical plane of the respective wheel 21A,21B. In a preferred embodiment, axes MA-MA₅MB-MB can be remote from the median plane of wheels 21A,21B. The relative tilt or inclination with respect to the vertical of axes MA- MA₅MB-MB is not necessarily equal to the tilt with respect to the vertical of steering axis S- S, and is determined on the basis of considerations known to the person skilled in the art in order to obtain an appropriate compromise between stability and maneuverability of vehicle 30. Preferably, the maximum allowable lateral tilt of axes MA-MA,MB-MB and steering axis S-S are between about 20° and 50° from vertical. Preferably, the range of allowable lateral tilt is centered when the vehicle body 2 or frame 1 is substantially vertical and the scooter 30 is on a substantially flat surface 28, with each wheel 21A,21B at the same vertical height with respect to each other.

The range of allowable lateral tilt of the axes of wheels 21A,21B and steering axis S-S is preferably controlled by projections 43A,43B that extend downward from respective ones of the upper suspension arms 11 A,l IB and corresponding bumpers 44A,44B which are affixed to the central support 7. Projections 43A,43B and bumpers 44A,44B are positioned to contact each other during tilting of tilt mechanism 31 when the tilting reaches a desired maximum range in order to prevent contact between other parts of the system at the end of the permitted tilting range of the mechanism and to restrict tilting of vehicle body 2 to a stable range. The distance between projections 43A,43B and bumpers 44A,44B is selected to provide the desired angle of tilt for the mechanism 31 and may vary with the overall geometry of the system.

Upper suspension arms 1 IA, HB preferably include respective shock-absorber mount extensions 23A,23B, which are preferably symmetrical relative to the longitudinal axis of vehicle 30 and extend upwardly. Articulated on the ends of said extensions 23A,23B are respective ends of suspension assembly 29, for example a combination of fluid shock absorber 25 and spring 27 (See Fig. 9). Suspension assembly 29 preferably tends to move extensions 23A,23B closer together and further apart upon compression and decompression thereof. Suspension assembly 29 further preferably includes a single unit, such as the depicted combination of a spring 27 and a fluid shock absorber 25, affixed between the linkages 70A,70B This arrangement eliminates the interference of suspension assembly 29 on the tilting of the vehicle 30

The elasticity of suspension assembly 29 permits movement, including simultaneous movement, of wheels 21A,21B of the scooter 30 m the same vertical direction with respect to each other, preferably independently of tilting thereof, between an upper end position and a lower end position For example, in the upper end position, the upper suspension arms 11 A,l IB and lower suspension arms 13A,13B pivot respectively in the upward direction U (Fig 1) about pivot axes V-V, W-W, thus allowing the wheels 21A,21B to move in the upward direction U, and causing extensions 23A,23B to move inward relative to each other in the direction I, compressing the fluid shock absorber 25 and spring 27 relative to each other Similarly, in the lower end position, the upper suspension arms 11A,1 IB and lower suspension arms 13A,13B pivot respectively in the downward direction D about pivot axes V- V, W- W, thus allowing the wheels 21 A,21B to move in the downward direction U, and causing extensions 23A,23B to move outward relative to each other in the direction O, decompressing the fluid shock absorber 25 and spring 27 Such a configuration prevents the irregularities of the road from transmitting bumps and vibrations to the rider via the steering control (for example, through handlebar 5 attached to the steering column 3), the bumps and vibrations instead being absorbed by suspension assembly 29 of vehicle 30 This makes πdmg on vehicle 30 particularly easy and pleasant In alternative embodiments, the suspension assembly can be attached to other parts of the tilt-mechanism, frame, and wheel assemblies, or in different variations to provide shock absorption for vehicle 30

Preferably fixed to the lower end of the steering column 3 is a steering link assembly 80 that is preferably linked to the uprights 17A,17B by joints 82A,83B, which are preferably ball or universal joints, and connecting rods 84A,84B, which are m turn connected via ball, universal, or other suitable joints to arm 86 that is preferably removably connected to steering column 3 so as to turn therewith Connecting rods 84A,84B are connected to uprights 17A,17B so as to be spaced apart from the steering axes MA-MA, MB-MB to pi o vide leverage such that turning of arm 86 by steering column 3 is translated to corresponding turning of wheels 21 A,21B by connecting rods 84A,84B As shown in Fig 11 a and 1 Ib, tilt mechanism 31 , described herein, permits lateral tilting of vehicle 30, for example through angle 46, advantageously to offset the centrifugal force when cornering the scooter 30 Advantageously, m embodiments where both the frame and wheels laterally tilt with respect to the vertical during curves, the resultant force exerted on the rider and vehicle body is kept generally between the wheels, preferably substantially centered, thus retaining stability of vehicle 30 as it turns around a curve. In the embodiment of Fig. 1 Ib, wheels 21A,21B substantially tilt along with frame 1, preferably remaining substantially aligned with frame 1 because they tilt to substantially the same inclination with respect to the vertical as frame 1. Tilt-mechanism 31 includes tilt- limiting members 52A,52B attached, preferably rigidly coupled, to each linkage 70AJ0B of tilt-mechanism 31, preferably to each upper suspension arm 1 IA, 1 IB. Caliper 56 is preferably rigidly affixed to a support member 54 and is preferably operable to engage both tilt-limiting members 52A,52B, which are curved brakes of materials suitable for disk brakes. The curvature and length of tilt-limiting members 52A,52B is selected such that, regardless of the position of the left and right linkages 70A,70B, tilt-limiting members 52A,52B remain in a position extending through caliper 56.

Caliper 56 is preferably movable between an engaged position and a disengaged position. When caliper 56 is in the engaged position, it restricts, and preferably locks, the movement of both right and left linkages 70A,70B and simultaneously locks relative movement therebetween, effectively locking out piston 25 and spring 25 of suspension system 29 as well. Caliper 56 can preferably be suddenly or gradually engaged or disengaged to suddenly lock out tilting mechanism 31 or to do so gradually. Alternatively, other known structures suitable for brakes may be used in the lilt-limiting system. Conversely, when caliper 56 is moved to the disengaged position, caliper 56 is disengaged from the tilt-limiting members 52A,52B, and the tilt-limiting members 52A,52B are free to move relative to caliper 56, steering tube IA, the frame 1. With caliper 56 in the disengaged position, the tilt limiting members 52A,52B are able to move between pads 58 of caliper 56. Upper suspension arms 1 IA, 1 IB can thus move in the upward direction U, and in the downward direction D as suspension arms 1 IA, 1 IB pivot about pivot axis V-V.

Additionally, wheels 21A,21B, as well as steering tube IA and frame 1, can also tilt laterally with respect to the vertical and surface 28 when caliper 56 is in the disengaged position. This arrangement allows the tilt-limiting mechanism to be selectively placeable in a locked or unlocked condition. As shown in Fig. 10, caliper 56 preferably includes a plurality of pads 58 slidably disposed along a pair of rods 59 therein (only one rod 59 is shown in the cross- section view of Fig. 12, the second rod being substantially parallel thereto). Each pad 58 includes a liner 63 and a backer 62. The backer 62 of each pad 58 is preferably made from a rigid material and engages rods 59 so as to be slidably suspended therefrom. Liner 63 is preferably made from a material that is typically used for a brake pad in a conventional disk brake arrangement and is affixed to backer 62 In a preferred embodiment, each tilt-hmitmg member 52A,52B has a pair of pads 58 configured for engagement therewith Specifically, tilt- lock member 52B, which, in the embodiment depicted m Fig 10, is disposed in front of tilt- lock member 52A, has pads 58C and 58D disposed on each side thereof Further, tilt-lock member 52A has pads 58A and 58B disposed on each side thereof In one embodiment, pads 58B and 58C can be affixed or integrally formed with one another

Preferably, pads 58 are freely slideable along rods 59, and pad 58A is adjacent to actuator 64 that is configured to move fore and aft in order to cause pad 58A to be pressed into engagement with tilt-limiting member 52A, which, in turn, causes the entire mechanism to be compressed such that tilt-hmitmg member 52A is gripped between pads 58A and 58B and tilt-hmitmg member 53B is gripped between pads 58B and 58C This causes the caliper 56 to engage tilt-limiting members 52A,52B to cause locking of tilt mechanism 31

Preferably actuator 64 is in the form of a power screw that is advanced within a threaded hole formed in caliper 56 by twisting thereof Preferably, twisting of actuator 64 is caused by movement of lever 66, which is controlled by cable 61, which is preferably a push-pull cable Preferably, cable 61 is controlled by motor 67, which is preferably controlled by a control system 118 (Fig 12) included in vehicle 30 Preferably, motor 67 is a bi-stable motor such that it is stable when it has moved the caliper 56 into the engaged position and when it has moved caliper 56 into the disengaged position This arrangement reduces strain on motor 67 and allows the tilt limiting mechanism to remain in the locked position even when no power is being supplied thereto Control system 118 can be configured to control motor 67 based on criteria received from sensors, which can be done using a computer Additionally or alternatively, control system 118 can receive input from the rider of the vehicle 30 relating to locking or unlocking of the tilt-limiting mechanism

Further, alternative mechanisms, such as pneumatic or hydraulic mechanisms, can be used to control caliper 56

Because tilt-hmitmg members 52A,52B are attached to upper suspension arms 1 IA, 1 IB in the preferred embodiment, upper suspension arms 11 A,l IB are locked in position relative vehicle, and thus to the preferred steering tube IA and frame 1, and are prevented from pivoting about pivot axis V-V when the tilt-hmitmg mechanism is in the locked condition As a result, frame 1, or wheels 21A,21B and frame 1, are substantially prevented from tilting laterally, and wheels 21 A.21B are prevented from moving in the upward direction U or the downward direction D Alternatively, the tilt-limiting mechanism can have a condition in which the tilting of wheels 21A,21B are limited to tilting within a predetermined range

Tilt-adjusting member 55 is mounted preferably to vehicle body 2 via weldment 90 (see Fig 8) that includes a plurality of arms 91 affixed to a pair of rails 92A,92B that are affixed to the outside of steering tube IA The plurality of arms 91 are arranged to appropriately space apart holder 93 from vehicle body 2. Weldment 90 may further include a plurality of secondary arms 96 that are configured for supporting additional parts associated with the vehicle, including various electronic components or exterior panels One end 72 of tilt-adjustmg member 55 is rotatably affixed to holder 73, and the other end 74 is rotatably affixed to support member 54, which is affixed to the central support 7. Caliper 56 is preferably rigidly affixed to support member 54, which is preferably pivotally mounted with respect to vehicle body 2, such as about hinge pin 76, which extends substantially longitudinally along axis V-V Preferably, suspension arms 1 IA, 1 IB to which the tilt- hmiting members 52A,52B are attached are also hinged from the same pivot pm 76 to maintain a generally concentric relationship between caliper 56 and the curvature of the tilt- hmiting members 52A 52B Tilt-adjusting member 55 is actuatable, preferably automatically, to rotate caliper 56 about the hinge pm 76. In this manner, when caliper 56 is in the engaged position to grip tilt-hmitmg members 52A,52B, tilt-adjusting member 55 is configured to move support member 54 and thus pivot the linkages 70 that are locked therewith to adjust and control the tilt of vehicle 30, when tilt-adjusting member 55 varies its length

In a preferred embodiment illustrated in Figs. 1 Ib and 1 Ic, tilt-adjustmg member 55 is used to perform a self-righting function of vehicle 30 In such an arrangement, caliper 56 is m an engaged state, while vehicle body 2 is positioned at angle 46, as shown in Fig l ib. Under normal circumstances, tilt-adjusting member 55 remains at a constant length 51 during free tilting of vehicle 30, thereby keeping caliper 56 aligned with steering axis S-S such that caliper 56 moves along the periphery of tilt-limiting members 52A,52B When the hlt-lockmg mechanism is actuated Caliper 56 gπpps onto tilt-limiting members 52A,52B in the tilted position, as shown in Fig 1 Ib Tilt-adjustmg member 55 is then actuated to either lengthen or shorten so as to push or pull support member 54 and, thus, tilt-lockmg members 52A,52B m an appropriate direction (shown as pulling in Fig. 1 Ic) so as to rotate through angle 48 in order to cause righting of vehicle body 2 In the embodiment shown m Fig l ie, angle 48 is equal to angle 46 but in an opposite direction Further, in Fig 1 Ic, tilt-adjusting member 55 is shortened to a length 52 that is less than its length 51 m Fig l ib In the embodiment shown, tilt-adjustmg member 55 would be lengthened to cause righting of tilting in the opposite direction

After vehicle 30 is returned to an upright position, support member 54, upon subsequent movement of caliper 56 to the disengaged position, is returned to its original, centered, position of Fig 11a A similar process can be carried out to allow for minor tilting adjustments for vehicle 30 without causing righting thereof In a preferred embodiment, righting, and possibly tilt adjustment, is carried out by an automated control system 118, which may include an onboard computer and associated speed and tilt sensors 125,127 Further preferably, control system 118 can adjust the tilt of vehicle 30 when the tilt-locking mechanism is in a locked state and vehicle 30 moves over varying terrain, m order to keep vehicle 30 upright Further preferably, the control system 118 that is used to control the movement of caliper 56 is the same that is used to control the tilt-adjusting member 55

Preferably tilt-adjusting member 55 includes a lmearly-advancing screw that is turned by a worm gear held in housing 57 that is preferably driven by a motor that is further held in housing 57 The screw is held in tilt-adjusting member 55 and may be turned into an end cap 53 with mating threads therein to cause lengthening or shortening of the tilt-adjusting member 55, which may further include an arm 65 associated therewith for stability The motor is preferably controlled by control system 118 that controls the movement, including the speed and direction, of the motor as well as when to turn the motor on and off, based on the desired tilt adjustment Alternatively, tilt-adjustmg member 55 can also incorporate pneumatic, hydraulic, or other suitable systems Control system 118 may incorporate a computer that can receive inputs from one or more sensors 125,126,127,128 configured to sense a parameter relating to motion of vehicle 30 Additionally or alternatively, control system 118 may be configured to receive user input in order to control tilt-adjustmg member 55

As discussed previously, both the tilt-lockmg and tilt-adjustmg functions of vehicle 30 can be carried out using a control system 118, which includes a controller 119 such as an on-board computer or other electronic circuitry The control system 118 is preferably automated so as to substantially control the tilt-limiting and tilt-adjusting functions without input from the rider of vehicle 30 Fig 14 shows a block diagram illustrating functional components of a preferred embodiment of a vehicle 30 that includes such a control system 118 While the vehicle of the present invention can be powered by a variety of suitable power plants, such as internal combustion engines, a preferred embodiment is powered by an electric motor 100 Vehicle 30 preferably has at least two wheels, and more preferably has three or four wheels. Alternative embodiments can have additional wheels on which the body of the vehicle is supported. Motor 100 can be a three-phase, slotted, brushless, permanent magnet motor, as described in U.S. Patent No. 6,326,765. Other embodiments can include motors with different specifications and configurations. In particular, motors having different numbers of poles, or having greater or lesser power and torque can be used.

Controller 119 is preferably electronically connected to motor 67 so as to control movement of caliper 56 between the engaged and disengaged positions, thereby controlling the tilt-limiting function of the vehicle. Controller 119 is further electronically connected to tilt-adjusting member 55 to control movement thereof, when caliper 56 has been moved into the engaged position, in order to control the tilt-adjusting function of vehicle 30, as described above. In this manner, controller 119 can further control the return of tilt- adjusting member 55 to its original position subsequent to tilt adjustment.

Controller 119 is preferably configured to receive input from sensor 125,126,127,128 configured to sense a parameter related to the movement of vehicle 30, the sensor is configured to then send a signal to controller 119, configured to operate components of the vehicle based on the sensed parameter. Vehicle 30 may include a plurality of sensors 125,126,127,128, each configured for sensing a different parameter. Not all sensors 125,12,127,128 shown are necessary in a preferred embodiment of vehicle 30. Preferably, at least one sensor relates to the movement of vehicle 30 and is used by controller 119 in determining when the tilt-limiting or tilt-adjusting functions are to be carried out.

In one embodiment, vehicle 30 includes one or more stop-and-go sensors, for example speed sensor 125, configured to measure the speed at which the vehicle is moving, such as by measuring the rotational speed of the rear wheel 10. Additionally or alternatively, vehicle 30 can include a acceleration sensor 126. The stop-and-go sensors can be used to control the tilt-limiting function based on the speed, acceleration, or both speed and acceleration, of the vehicle. At high speeds, it is preferred that caliper 56 remain in the disengaged position to allow frame 1, or wheels 21A,21B and frame 1, to tilt laterally relative to the vertical and surface 28, and allow wheels 21A,21B to freely move in the vertical direction with respect to frame 1, so as to enable the advantageous steering and driving benefits of tilt mechanism 31 as vehicle 30 takes curves or moves over bumps in the road.

In an embodiment using speed sensor 125, when the speed of vehicle 31 moves below a preselected locking threshold speed, for example at less than about 5 mph, from a higher speed, controller 119 identifies that the locking threshold speed has been passed, and controller 119 automatically causes caliper 56 to move into the engaged position to prevent or restrict undesired tilting of frame 1, or wheels 21A,21B and frame 1, and possible loss of balance by the rider Preferably, the threshold locking speed that triggers automatic movement of caliper 56 to the engaged position is less than about 10 mph, and more preferably less than about 5 mph, and most preferably less than about 4 mph, and is preferably more than about 0 5 mph, and more preferably more than about 2 mph

When the speed of vehicle 30 increases from stand still or other relatively low speed to a higher speed that is past an unlocking threshold speed, for example of about 3 or 4 mph, controller 119 identifies that such a speed has been passed, based on the input from speed sensor 125 Controller 119 then causes caliper 56 to move to the disengaged position Preferably, the threshold unlocking speed is at least about 2 mph, and preferably less than about 10 mph, and more preferably less than about 5 mph Preferably, this unlocking threshold speed is less than the unlocking threshold speed, but in one embodiment, they are equal In some embodiments, controller 119 automatically causes caliper 56 to move to the disengaged position upon movement of the vehicle m the forward direction, actuation of throttle 22 by the rider, or placement of the rider's feet upon foot rests 14 In other embodiments, speed sensor 125 can send a signal directly to motor 67 when the vehicle passes below a locking threshold speed or above an unlocking threshold speed, thus triggering automatic movement of caliper 56 between the engaged and disengaged positions In another embodiment, tilt mechanism 31 includes an inclination sensor 127, for example a gyroscope, an inclinometer, or another suitable sensor, such as a solid-state accelerometer associated with a processor Inclination sensor 127 is preferably configured to sense the angle of inclination 46 of vehicle body 2 or frame 1 with respect to the vertical or surface 28, at least when the vehicle is at a stand still or moving at slow speeds

Alternatively, inclination sensor 127 can be configured as an apparent gravity sensor such that it can sense whether and to what extent the force on the center of gravity of vehicle has deviated from a position that is aligned with the longitudinal plane of vehicle 30 In a preferred embodiment, at relatively slower speeds inclination sensor 127 can sense when wheels 21 A,21B or frame 1 are beginning to tilt to either side, which may indicate that the rider is losing balance of the scooter In response, caliper 56 is preferably automatically moved to the engaged position to lock wheels 21A,21B and frame 1 with respect to each other and prevent lateral tilting of vehicle 30 Additionally, tilt-adjustmg member 55 can be actuated in such a situation to right vehicle 30, if necessary As explained above, tilting of frame 1, or wheels 21A,21B and frame 1, is preferably allowed at higher speeds, so caliper 56 preferably remains in the disengaged position at these speeds irrespective of input by inclination sensor 127.

In a further embodiment, steering sensor 128 is included in the steering mechanism, for example in the steering tube IA or in one or more of joints 15A,15B or 18A,18B. Such a sensor is preferably capable of determining the angle at which wheels 21A,21B are turned with respect to the longitudinal axis of the vehicle body 2. The input from sensor 128 can be used by controller 119 to limit the speed of vehicle 30 when the tilt- limiting mechanism is in the locked state such that vehicle 30 is held in an upright position. Such action is taken when wheels 21A,21B are steered to a steering angle of at least a steering threshold angle, which for example, may be about 10° and more preferably about 5° on either side with respect to the longitudinal axis of vehicle body 2. Most preferably the steering threshold angle is between about 2° and 3°. Limiting of the speed of vehicle 30 is such that vehicle 30 cannot reach a speed exceeding about 10 mph and more preferably exceeding about 5 mph. Alternatively controller 119 can be configured to limit the acceleration of vehicle 30 when wheels 21 A,21B are turned beyond the threshold angle. Such action, further preferably involves receiving an input from speed sensor 125 or acceleration sensor 126. Further preferably, the acceleration restriction is proportional to the angle at which the wheels 21A,21B are turned such that, the greater the angle, the lower the limit for speed. Alternatively, controller 119 can be connected to an actuator 140 that is arranged to connect to a portion of the steering mechanism, for example arm 84, so as to limit the steering angle of wheels 21A,21B based on the speed or acceleration of vehicle 30 when caliper 56 is in the engaged position.

In one embodiment, controller 119 is further configured to receive input from the rider of the vehicle 30 using a user-input device 129 that may be in the form of a button, lever or the like. Rider input causes an electrical signal to be sent to controller 119 to allow the user to influence the control of the tilt-limiting or tilt-adjusting functions. In one such embodiment, user input 129 is in the form of a pushbutton, wherein the control system 118 is configured to allow the rider to manually cause caliper 56 to move into the engaged position. Controller 119 may be configured to maintain caliper 56 in the engaged position until further rider input indicating to move the caliper 56 to the unlocked position. This embodiment allows the rider to provide instantaneous tilt locking and extended locking to assist, for example, in parking or driving in slow-moving traffic. Additionally or alternatively user input 129 can allow the rider to make manual adjustments to the tilt-adjusting member 55. In certain embodiments, it is preferred to configure controller 119 with an override function to automatically alter the rider-selected condition, for example, when the rider's selection is potentially unsafe, which may occur when the inclination sensor 127 determines that the apparent gravity of vehicle 30 is pointed outside of wheels 21A,21B. For example, controller 119 may allow the rider to select a state where tilting of vehicle 30 is locked. Such an embodiment is useful when vehicle 30 is driven in heavy, frequently- stopping traffic. In this embodiment, controller 119 can be configured, for example to unlock tilting if a speed of, for example 15 mph is reached and exceeded. Similarly, controller 118 can be configured to unlock the tilting of vehicle 30 if the wheels are turned, for example, past an angle of about 25°. This action can further depend on the speed or acceleration of vehicle 30. Such functions may include controller 119 receiving input from sensors 125,126,127,128.

In the preferred embodiment of a scooter, motor 100 receives a three-phase voltage from motor controller 102. Motor controller 102 is also preferably controlled by controller 119, and has the battery DC voltage as its input and converts the battery voltage to a three-phase output to the motor 100. Preferably, motor controller 102 outputs a modulated signal, such as pulse width modulation, to drive motor 100. Motor controller 102 preferably includes high-power semiconductor switches which are gated (controlled) to selectively produce the waveform necessary to connect battery pack 104 to motor 100. Controller 119 preferably sends signals to motor controller 102, battery charger 106 (when provided on-board the scooter), on-board power generating source 112, and converter/charge controller 116. The charge of battery pack 104 is monitored via battery monitor 120, which in turn is connected to controller 119 to provide information which can affect the operation of controller 119. The energy state of the battery pack 104 is displayed on battery gauge 122 so that the rider can monitor the condition of the battery pack 104, much like a fuel gauge is used on a gasoline powered scooter. The status of the fuel supply in the tank is similarly displayed on fuel gauge 124 for the rider's convenience. In an alternative hybrid-powered embodiment, the on-board power generating source 112 charges the batteries that power the motor, but no separate charger or charging circuit is provided. The term "about," as used herein, should generally be understood to refer to both the corresponding number and a range of numbers. Moreover, all numerical ranges herein should be understood to include each whole integer within the range.

While illustrative embodiments of the invention are disclosed herein, it will be appreciated that numerous modifications and other embodiments can be devised by those skilled in the art. Features of the embodiments described herein, can be combined, separated, interchanged, or rearranged to generate other embodiments. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments that come within the spirit and scope of the present invention.

Claims

THE CLAIMSWhat is claimed is:

1. A vehicle, comprising: a vehicle body configured for supporting a rider and having a longitudinal axis; first and second tilting wheels disposed respectively at different lateral positions with respect to the longitudinal axis and configured to turn in a horizontal plane; a tilt mechanism supportively associating the vehicle body from the tilting wheels to enable the vehicle body to tilt through a predetermined tilt range with respect to a surface on which the tilting wheels are disposed; a tilt-lock mechanism operatively associated with the tilt mechanism and selectively placeable in a locked condition to limit the tilting of the vehicle body; a first sensor configured for sensing a parameter relating to the configuration of the tilt mechanism; a motor configured for powered movement of the vehicle; and a control system associated with the sensor and configured to control an amount of power supplied to the motor based on the parameter sensed by the sensor.

2. The vehicle of claim 1, wherein the first sensor is configured for sensing an angle of steering by which the first and second tilting wheels are turned with respect to the vehicle body, wherein the controller is configured to limit acceleration of the vehicle by limiting the amount of power supplied to the motor, depending on the sensed steering angle.

3. The vehicle of claim 2, further comprising a second sensor configured for sensing whether the tilt-lock mechanism is activated to lock the tilting of the vehicle body, wherein the controller is configured for limiting the acceleration of the vehicle by limiting the amount of power supplied to the motor when the sensor senses that the tilt-lock mechanism is locked.

4. A vehicle, comprising: a vehicle body having a longitudinal axis and being configured for supporting a rider, first and second tilting wheels disposed respectively at different lateral positions with respect to the longitudinal axis and configured to turn in a horizontal plane; a tilt mechanism supportively associating the vehicle body from the tilting wheels to enable the vehicle body to tilt with respect to a surface on which the tilting wheels are disposed, a tilt-lock mechanism operatively associated with the tilt mechanism and selectively placeable in a locked condition to limit or fix the tilting of the vehicle body, a first sensor configured to sense a speed of the vehicle, a control system associated with the sensor and configured for releasing the tilt- lock mechanism from the locked condition when the sensed speed climbs above a predetermined first threshold speed value, and a user input that is manually-activatable by the rider for causing the controller to maintain the tilt-lock m the locked position when the detected speed rises above said first threshold speed value.

5 The vehicle of claim 4, wherein the control system is further configured to unlock the tilt-lock mechanism with the user-mput activated, when the sensed speed is above a second speed threshold value that is higher than the first speed threshold value

6. The vehicle of claim 4, wherein the control system further includes a second sensor configured for sensing the angle through which the tilting wheels are turned, and wherein the control system is configured to override the user selected lock of the tilt-lock mechanism if the speed of the vehicle is above a higher speed threshold and the angle of the tilting wheels exceeds a predetermined threshold angle

7 A vehicle, comprising" a vehicle body configured for supporting a rider and having a longitudinal axis, first and second tilting wheels disposed respectively at different lateral positions with respect to the longitudinal axis and configured to turn in a horizontal plane; a tilt mechanism supportively associating the vehicle body from the tilting wheels to enable the vehicle body to tilt through a predetermined tilt range with respect to a surface on which the tilting wheels are disposed; a tilt-lock mechanism operatively associated with the tilt mechanism and selectively placeable in a locked condition to limit or fix the tilting of the vehicle body; at least one sensor configured for sensing a parameter relating to motion of the vehicle; and a control system associated with the a sensor and configured to control a movement associated with the tilt mechanism based on the parameter sensed by the sensor.

8. The vehicle of claim 7, wherein the parameter relating to the motion of the vehicle is speed or acceleration of the vehicle, and wherein the control system is configured for limiting a turning angle of the tilting wheels.

9. The vehicle of claim 8, further including a motor configured for powered movement of the vehicle, wherein acceleration of the vehicle is caused by supplying power to the motor, and wherein the sensor is configured to sense the amount of power supplied to the motor.

10. The vehicle of claim 8, further including a steering mechanism connected to the tilting wheels to cause turning of the tilting wheels in the horizontal plane, and wherein the control system is configured to control an actuator configured to block movement of the steering mechanism in order to limit the turning angle of the tilting wheels.

11. A vehicle tilting unit, comprising: an attachment member configured for removable mounting to a vehicle body in supporting association therewith; first and second wheel supports disposed respectively at different lateral positions with respect to a longitudinal axis and configured for mounting vehicle wheels thereto; and a tilt mechanism connected to support the attachment member from the wheel supports and allow the wheel supports to move vertically in opposite directions with respect to the attachment member to allow the attachment member and body to tilt with respect to a surface on which the vehicle wheels are disposed.

12. The unit of claim 11 , further comprising a steering mechanism that includes: a steering column rotatably associated with the vehicle body; and a turning mechanism removably connected to the steering column and having a pair of steering rods attached to the tilt mechanism, such that turning of the steering column results in turning of the first and second wheel supports.

13. A vehicle comprising: the vehicle tilting unit of claim 12; and a vehicle body removably attached to the attachment member and supported by front wheels that are mounted to the wheel supports and by a rear wheel and for supporting a rider substantially between the front and rear wheels, the vehicle body being configured for substituting the support assembly with a front fork that includes a single steerable wheel.

14. The unit of claim 11, wherein the tilt mechanism includes: a central support disposed along the longitudinal axis, a first linkage connecting the first wheel support to the central support; and a second linkage connecting the second wheel support to the central support; wherein a shock-absorbing member is disposed between the first and second linkages; and wherein the tilt mechanism further includes a tilt-limiting mechanism with a first tilt-limiting member affixed to the first linkage, a second tilt-limiting member affixed to the second linkage, and a caliper affixed to the central support, the caliper being configured to engage tilt-limiting members and to hold the first and second tilt-limiting members in a substantially fixed position relative to the central support.

15. The assembly of claim 11 , wherein the attachment member is configured for fastening to the vehicle body at at least three spaced locations.

16. A vehicle support assembly, comprising: a central support configured to supportably attach to a vehicle that has a longitudinal axis and including a top pivot axis and a bottom pivot axis; a first linkage and a second linkage, each extending laterally from the central support on opposite sides of the longitudinal axis, each of the first linkage and second linkage including: a top suspension arm having an inside end that is pivotably mounted to the central support at the top pivot axis, a bottom suspension arm having an inside end that is pivotably mounted to the central portion at the bottom pivot axis, and a generally upright strut having a universally pivotable connection with outer ends of both the top and bottom suspension arms; and first and second wheels supportmgly mounted from each of the upright struts.

17. The assembly of claim 16, wherein the suspension arms and upright struts are substantially rigid and subjected to dynamic loading, and wherein the universal associations between the bottom suspension arms and the upright struts permit deflections of the upright struts due to the dynamic loading.

18. The assembly of claim 17, wherein the deflections of the upright struts are in a plane that is substantially parallel to the longitudinal axis of the vehicle.

19. The assembly of claim 16, further comprising a shock absorbing member connecting the first and second linkages without connection to the central portion.