GB2547952A

GB2547952A - Auxiliary support

Info

Publication number: GB2547952A
Application number: GB1603827.5A
Authority: GB
Inventors: Brown Carson; Malcolm Fraser Grant; James Godden Stephan
Original assignee: Uniwheel Ltd
Current assignee: Uniwheel Ltd
Priority date: 2016-03-04
Filing date: 2016-03-04
Publication date: 2017-09-06
Also published as: GB201603827D0

Abstract

An auxiliary support/stabilizer arrangement for a powered unicycle (100, Fig 1) comprises a wheel arrangement 620 having at least one wheel 625, connecting means 610 for connecting the auxiliary device to the unicycle and a suspension arrangement 630 coupled between the connecting means 610 and the wheel arrangement 620; the suspension 630 allowing movement of the wheel arrangement 620 with respect to the connecting means 610. The suspension 630 may comprise an elastically deformable element, preferably a flexible elongate member such as a quarter leaf spring. In some arrangements it is preferable that the deformable element be variable stiffness in stiffness, this preferably being realised by providing the deformable element as a plurality of flexible elements connectable together; the plurality of flexible elements co-operating to define an overall stiffness of the deformable element. In one arrangement (Fig 8) the flexible elements may be stacked, in another (Fig 9), the elements may be connected end-on-end. It is also taught that the at least one wheel 620 may be angled with respect to the driving wheel of the unicycle.

Description

AUXILIARY SUPPORT

Field of Invention

The present invention relates to powered single-wheeled devices and more particularly to auxiliary supports for powered unicycles.

Background to the Invention

Powered vehicles for use while standing are known. Such vehicles include two-wheeled vehicles and single-wheeled vehicles (i.e. unicycles). A typical powered unicycle device has self-balancing functionality, having an electronic or mechanical system that controls the wheel in the appropriate direction is typically used to achieve fore-and-aft balance. This type of automatic fore-and-aft balance technology is well known and described, for example, in United States Patent number 6,302,230. A sensor and electronic equipment are typically provided. Information detected by the sensor and the electronics is relayed to a motor. The motor drives the wheel in the appropriate direction and at sufficient speed to maintain fore-and-aft balance.

Known embodiments of a powered unicycle do not include a handle bar supported by a shaft. For example. United States Patent Application Serial Number 12/281,101 presents a single wheel, coupled to a frame to which two platforms (one on each side of the wheel) are attached.

Summary of the invention

There is herein proposed the concept of an auxiliary support for a powered unicycle device. The auxiliary support comprises connecting means adapted to connect the auxiliary support to the powered unicycle device; a wheel arrangement comprising at least one wheel; and a suspension arrangement coupled between the connecting means and the at least one wheel, and adapted to permit the wheel arrangement to move with respect to the connecting means.

In other words, there is proposed the concept of an auxiliary support, stabiliser or satellite wheel arrangement for a powered unicycle device. The auxiliary support is adapted to support a leaning of the powered unicycle device by moving with respect a connecting means connectable to the powered unicycle device.

The auxiliary support is adapted to be connectable to the powered unicycle device via connecting means. That is to say, the auxiliary support may be coupled to the unicycle device. The auxiliary support comprises a wheel arrangement having at least one wheel. A suspension arrangement couples the wheel arrangement to the connecting means of the auxiliary support, thereby coupling the wheel arrangement to the unicycle device. The suspension arrangement is adapted to allow or permit the wheel arrangement to move with respect to the connecting means (and thereby the unicycle device). The suspension arrangement is preferably adapted to dampen or hinder the movement of the wheel arrangement relative to the unicycle device, such that a leaning of the unicycle device is inhibited, hindered or hampered.

The auxiliary support supports a leaning of the powered unicycle device, such that a leaning of the powered unicycle device is hindered, restricted or otherwise dampened. As the unicycle device leans (i.e. towards the auxiliary support) the auxiliary support slows down a leaning of the unicycle device by coupling the unicycle device to a ground surface via the suspension arrangement. That is to say, the wheel arrangement couples to a ground surface, and the suspension arrangement slows down or hinders a leaning. The suspension arrangement may thereby be thought of as a dampening member, dampening a leaning force of the unicycle device.

In this way, excessive or inappropriate fast leaning of the unicycle device can be prevented. This may be particularly advantageous for an inexperienced or new user of the unicycle device, so that they may be taught in what manner the unicycle device responds to a lean, for example to learn how to steer the unicycle device, whilst remaining supported.

Optionally, the connecting means is adapted to connect to a frame of the powered unicycle device.

Connecting the auxiliary support to a casing of the unicycle device allows for the auxiliary device to more directly assist in the righting of the unicycle device.

In other embodiments, the auxiliary support may be connected to a foot platform of the unicycle device. Such an attachment may advantageously increase the feedback possible to a user (as they are more directly connected to the auxiliary support).

In preferable embodiments, the auxiliary support is connected to a casing element positioned below a foot platform of the unicycle device. This allows a greater flexibility and dynamism in leaning as well as providing an aesthetically pleasing auxiliary support.

In a preferable embodiment the suspension arrangement comprises an elastically deformable element. In at least one such embodiment, the elastically deformable element comprises a flexible elongate member.

In other words, the elastically deformable element may form a deformable beam connected between the wheel arrangement and the connecting means. The elongate member may flex and bend in response to a leaning of the unicycle device so as to support the leaning of a user by providing a restoring or resistive force to the unicycle device in response to the leaning.

The elastically deformable member may be adapted to elastically move the wheel arrangement with respect to the connecting means by a vertical distance of at least 3mm. In other words, the elastically deformable member may be adapted to deflect by at least 3mm, and elastically return to an original position (i.e. automatically reverse a deflection).

The elastically deformable element may be adapted to have a variable stiffness, and wherein the auxiliary support comprises an adjustment arrangement adapted to adjust the stiffness of the elastically deformable element.

Put another way, an adjustment arrangement of the auxiliary device may be adapted to adjust a stiffness of the elastically deformable member. This may be performed, for example, by changing a shape of the elastically deformable element, increasing a weight on the elastically deformable member, changing a material of the elastically deformable member, adjusting a length of the elastically deformable member and so on.

In at least one embodiment, the elastically deformable element comprises a plurality of flexible elements connectable together, wherein the plurality of flexible elements cooperate to define an overall stiffness of the elastically deformable element

In other words, the elastically deformable element may comprise more than one flexible elements which may be connected together to thereby define the stiffness of the elastically deformable element. Each flexible element may comprise the same or different material as the other flexible elements.

For the avoidance of doubt, it will be apparent that in some embodiments the elastically deformable member may comprise only a single flexible element.

The flexible elements may be stackable, such that the length of the elastically deformable element is substantially the same for any number of flexible elements.

In other words, the flexible elements may be positioned one on top the other, so as to change an overall thickness of the elastically deformable element and thereby adjust the stiffness of the said elastically deformable element.

In other or further embodiments, the flexible elements are connectable end-on-end, such that the length of the elastically deformable element increases with the number of flexible elements.

Put another way, the plurality of flexible elements may be connectable together so as to adjust a length of the elastically deformable element to thereby adjust the stiffness of the said elastically deformable element. Such an embodiment may also advantageously change a position of the wheel arrangement relative to the unicycle device so as to selectably move a location at which the wheel arrangement engages with a ground surface.

In preferable embodiments, the auxiliary support is, in use, adapted to contact a ground surface when connected to the unicycle device.

It will be apparent that the term ‘in use’ may be interpreted as meaning when the unicycle device is substantially orthogonal to a ground surface or when the unicycle device is leaning in a direction of the auxiliary support. That is to say, when the unicycle device is at rest, the auxiliary support is adapted to contact a ground surface. The auxiliary support may be considered to be not in use as the unicycle device leans away from the auxiliary support.

The suspension arrangement may comprise an elastic material formed of polycarbonate, wherein optionally the elastically deformable element is formed as a quarter-elliptical leaf spring.

In preferable embodiments, when connected to the unicycle and at rest, at least one wheel of the wheel arrangement is angled with respect to a wheel of the powered unicycle device.

In embodiments, the angle of at least one wheel of the wheel arrangement with respect to a wheel of the powered unicycle device is adapted to alter in response to a leaning of the powered unicycle device.

The wheel arrangement may comprise at least one wheel mounted on an axle, wherein the suspension arrangement is connected to only a single end of the axle.

Optionally, the suspension arrangement comprises at least one of: a torsion spring; a leaf spring; a coil; a shock absorber; a hydraulic system; a pneumatic system; a v-spring; an air spring; an inflatable bag; a flexible beam; and a linkage arrangement.

According to an embodiment of the invention, there may be provided a powered unicycle comprising: a single primary wheel adapted to rotate about a primary axis of rotation; a balance control system adapted to maintain fore-aft balance of the unicycle device by controlling rotation of the primary wheel; a foot platform for supporting a user of the unicycle device; and an auxiliary support as previously described.

Brief description of the drawings

An example of the invention will now be described with reference to the accompanying diagrams, in which: FIG. 1 is an isometric view of an embodiment of a powered unicycle device in a closed configuration; FIG. 2 is an exploded diagram of components internal to the casing of FIG. 1, FIGS. 3A & 3B are side and front elevations, respectively, of the embodiment of FIG. 1, wherein the casing is moving between a closed and open configuration; FIGS. 4A & 4B are side and front elevations, respectively, of the embodiment of FIG. 1, wherein the casing is in an open configuration and the foot platforms are in a stowed configuration; FIGS. 5A & 5B are side and front elevations, respectively, of the embodiment of FIG. 1, wherein the casing is in an open configuration and the foot platforms are in an active configuration; FIGS 6A & 6GB are side and isometric elevations, respectively, of an embodiment of an auxiliary support; FIGS 6C & 6C are side views of a unicycle device connected to an auxiliary support of FIG 6A & 6B at a first angle of lean and a second angle of lean respectively; FIGS 7A & 7B are respective side views of an embodiment of an auxiliary support connected to a unicycle device at a first angle of lean and a second angle of lean; FIG 8A illustrates an auxiliary support according to an embodiment; and FIG 9A is an exploded view of an auxiliary support according to an embodiment.

Detailed description

Proposed is the concept of an auxiliary support comprising a wheel arrangement and connecting means, the connecting means being adapted to connect the auxiliary device to the powered unicycle device. The wheel arrangement and connecting means are coupled by a suspension arrangement, so as to allow movement of the wheel arrangement with respect to the connecting means.

The term vertical, as used herein, means substantially orthogonal to the generally horizontal ground surface upon which a unicycle may be ridden. The term lateral, as used herein, means substantially parallel to the generally horizontal ground surface. Also, terms describing positioning or location (such as above, below, top, bottom, etc.) are to be construed in conjunction with the orientation of the structures illustrated in the diagrams.

The diagrams are purely schematic and it should therefore be understood that the dimensions of features are not drawn to scale. Accordingly, the illustrated thickness of any of the components or features should not be taken as limiting. For example, a first component drawn as being thicker than a second component may, in practice, be thinner than the second component. FIGS. 1-5 show one embodiment of a powered unicycle device 100 which is described for the purposes of understanding. FIG. 1 shows the powered unicycle device 100 with a casing 110 in a closed configuration so that it encases a single wheel 120. Here, the casing 110 is formed from a first, upper portion 110A that covers the top (uppermost) half of the wheel 120, and a second, lower portion 11 OB that covers the bottom (lowermost) half of the wheel 120. FIG 2 illustrates an exploded view of components internal to the casing 110, namely a wheel 120 and drive arrangement 135.

Referring back to FIG. 1, the wheel 120 spins about a central axis 125. The first, upper portion 110A of the casing is retained in a fixed position relative to the central axis 125, whereas the second, lower portion 110B of the casing is adapted to rotate about the central axis 125. Rotation of the second lower portion 11 OB about the central axis 125 moves the casing between closed and open configurations (as illustrated by FIGS. 3-4). In the closed configuration (shown in FIG. 1), the casing 110 encloses the wheel 120 so that the outer rim 130 of the wheel 120 is not exposed. In the open configuration (shown in FIGS.4- 5), the outer rim 130 of the wheel 120 is exposed so that it can contact a ground surface.

For the avoidance of doubt, references to the single wheel 120 should be taken to mean the generally circular unit that is positioned between the legs of a user and adapted to rotate about an axis to propel the unicycle in a direction during use. The single wheel 120 may therefore be formed from one or more tyres and/or hubs that are coupled together (via a differential, for example). For example, an embodiment may comprise a single hubless wheel having a single hubless rim with a plurality of separate tyres fitted thereon. Alternatively, an embodiment may comprise a single hubless wheel formed from a plurality of hubless rims (each having a respective tyre fitted thereon), wherein the plurality of hubless rims are coupled together via a differential bearing arrangement. In some conceivable embodiments, the single wheel may be substantially spherical in shape, so as to be rotatable about more than one axis.

Referring now to FIG. 2, rotation of the single wheel 120 is driven by a drive arrangement 135 according to an embodiment. The drive arrangement 135 includes guide wheels 140 attached to an outwardly facing side of respective batteries 145. In this embodiment, there are two pairs of angled guide wheels 140, wherein the two guide wheels in each pair share are tapered or conical such that they have a sloped surface which is not perpendicular to the radial plane of the single wheel 120. Put another way, the contact surface of each guide wheel is inclined with respect to the radial plane of the single wheel 120. The guide wheels 140 of each pair are also positioned spaced apart to provide a gap between the two guide wheels of a pair. A rib 150 is provided around the inner rim of the wheel 120 and fits into the gap between the two guide wheels 140 in each pair. The guide wheels 140 are therefore adapted to contact with the inner rim of wheel 120 where they spin along with wheel 120 and hold wheel 120 in place by way of the rib 150. Of course, it will be appreciated that other arrangements, including those with only one guide wheel per battery 145, are possible.

The batteries 145 are mounted on a motor 155 which drives a pair of drive wheels 160 positioned at the lowermost point along the inner rim of the wheel 120. The batteries 145 supply power to motor 155 and, in this embodiment, there are two batteries in order to create a balanced distribution of volume and weight. However, it is not necessary to employ two batteries 145. Also, alternative energy storage arrangements may be used, such as a flywheel, capacitors, and other known power storage devices, for example.

The drive arrangement 135 is adapted to be fitted inside the wheel. In other words, the drive arrangement is sized and shaped so that it can be positioned in the void defined by the inner rim of the wheel 120. Further, the drive arrangement 135 is movable between a locked configuration and an unlocked configuration.

In the locked configuration, when fitted inside the wheel 120, the drive arrangement 135 engages with the rim of the wheel 120 to prevent its removal from the wheel. Here, in the embodiment shown, the guide wheels 140 contact the inner rim of wheel 120 and hold wheel 120 in place by way of the rib 150 when the drive arrangement is in the locked configuration.

In the unlocked configuration, when fitted inside the wheel 120, the drive arrangement 135 disengages with the rim of the wheel 120 to permit its removal from the wheel. Here, in the embodiment shown, the drive arrangement contracts in size when moved from the locked configuration to the unlocked configuration so that the guide wheels 140 no longer contact the inner rim of wheel 120 and no longer hold the wheel 120 in place by way of the rib 150. Such reduced size (e.g. diameter) of the drive arrangement 135 when in the unlocked configuration thus enables the drive arrangement 135 to be removed from the wheel 120.

It will therefore be understood that the drive arrangement 135 of the illustrated embodiment can be quickly and easily connected or removed to/from the wheel 120 for repair or replacement, for example. Arranging the drive arrangement 135 in the unlocked configuration permits its removal or fitting from/to the wheel 120 (because, for example, its dimensions when in the unlocked configuration permit its fitting inside the wheel). When fitted inside the wheel 120, the drive arrangement can be arranged in the locked configuration so that it engages with the rim of the wheel 120 to prevent its removal (because, for example, its dimensions when in the locked configuration prevent the drive arrangement from being removed from the wheel).

When the drive arrangement 135 is fitted inside the wheel and in the locked configuration, a pair of drive wheels (not visible in Figure 2) is adapted to contact the inner rim of the wheel 120. Here, the pair of drive wheels comprises first and second rollers that are inclined with respect to the radial plane of the wheel. By way of contact with the inner rim of the wheel 120, the drive wheels transmit torque from the motor 155 to the wheel 120. It will be understood that this drive system operates by friction and it may be preferable to avoid slippage between the drive wheels and the inner rim of wheel 120. Positioning the drive wheels at the lowermost point enables the weight of a user to provide a force which presses the drive wheels against the inner rim of the wheel 120, thereby helping to reduce or avoid slippage.

Referring to FIGS. 4-5, two foot platforms 165 are coupled to the second, lower portion 110B of the casing 110, with one on each side of wheel 120. In the open configuration, the foot platforms 165 are movable between a stowed configuration, wherein the foot platforms are substantially parallel with the plane of the wheel (as shown in FIG. 4), and an active configuration, wherein the foot platforms are substantially perpendicular to the plane of the wheel (as shown in FIGS. 5) so as to support a user’s weight. Thus, in this embodiment, the foot platforms 165 are movable between: (i) a stowed configuration wherein they are flat against the side of the wheel and can be rotated (with the second, lower portion 110B of the casing) about the central axis 125 so as to be positioned inside (and covered by) the first, upper portion 110A of the casing; and (ii) an active configuration, wherein. Accordingly, the foot platforms 165 are upwardly foldable into a stowed configuration that narrows the profile of the unicycle 100 to aid in storage and carrying. In use, the foot platforms are moved to the active configuration, and the user stands with one foot on each platform 165.

The drive arrangement 135 includes a gyroscope or accelerometer system 170 which senses forward and backward tilt of the device in relation to the ground surface and regulates the motor 155 accordingly to keep the device upright. In this way, the user is provided a way of controlling the acceleration and deceleration of the unicycle by varying the pressure applied to various areas of the foot platforms 165. It also enables the unicycle to self-regulate its balance in the fore-and-aft plane.

In order to control a rotation of the unicycle device 100, that is to perform a turning maneuver, the user may lean or tilt the unicycle device sideways. The gyroscopic effect of the lean or tilt will cause the device to begin performing a turn (e.g. undergo a banked turn). This well-known phenomenon may also called precession. In this way, the user is given a degree of control over the direction of travel by shifting his weight on the foot platforms 165 so as to cause the device to lean and thereby change direction. In other words, the user may steer the unicycle device by changing an amount of leaning (by shifting a body weight of the user).

When not in use, the foot platforms 165 are moved to the stowed configuration and then rotated (with the second, lower portion 11 OB of the casing) about the central axis 125 so as to move the casing to the closed configuration. Thus, in the closed configuration, the foot platforms 165 are stored inside the casing (covered by the first, upper portion 110A of the casing).

It may be understood that the casing may be formed from a frame and a protecting coating mounted on the frame. The frame may mount components, such as the drive arrangement and the foot platforms, thereon.

The embodiment of FIGS. 1-5 also comprises a lifting handle 180 coupled to the drive arrangement 135 via a plurality of rods 185. The lifting handle 180 is positioned at the top of the casing 110, above the wheel 120, and may be used to hold the unicycle 100 above the ground, for example to enable a user to lift, carry, convey or place the unicycle 100. A retractable carrying strap 190 is also provided and attached to the top of the casing 100. The carrying strap 190 may be used to carry the unicycle 100, for example over the shoulder of user. A hook may be provided on the bottom of the case to create rucksack-like belts from the carrying strap 190. The carrying strap 190 may also be used to pull the unicycle 100, for example when the auxiliary supports (detailed below) are in contact with the ground/supporting surface).

It will be appreciated that other embodiments may employ other actuator arrangements and/or mechanisms for moving the auxiliary support between a stowed and active configuration. By way of example, a telescoping actuator arrangement may be employed to move the auxiliary support between a stowed configuration and an active position. Also, an actuator may comprise any suitable arrangement for affecting or driving movement of the auxiliary support(s). For example, embodiments may comprise one or more hydraulic, electric or mechanical actuators adapted to move the auxiliary support(s) between an extended and retracted configuration.

It will also be appreciated that other embodiments of a unicycle device 100 may be used with an auxiliary support according to an aspect of the invention, the above description being merely for the sake of clarity and completeness.

Possible embodiments of an auxiliary support for a powered unicycle device (such the device described with reference to FIGS 1-5) will now be elucidated with reference to FIGS. 6-9

With reference now to FIGS 6A-6B, in a first embodiment, the auxiliary support 600 comprises connecting means 610, a wheel arrangement 620 and a suspension arrangement 630. FIG 6C exhibits a powered unicycle device having a connected auxiliary support according to the first embodiment when the powered unicycle device is in a ‘rest state’ (i.e. there is no substantial side leaning). FIG 6C illustrates a powered unicycle device having a connected auxiliary support according to the first embodiment when the powered unicycle is leaning sideways (e.g. for the purposes of steering).

The connecting means 610 is adapted to connect the auxiliary support to the powered unicycle device 100. The connecting means may comprise, for example, a clipping mechanism adapted to clip the auxiliary support to the powered unicycle device. In other examples, the connecting means may comprise a magnetic element adapted to connect to magnetic material of the powered unicycle device. In other conceivable embodiments, the connecting means comprises a fastener (e.g. a clamp, peg, clasp, grommet, nail, threaded fastener, strap and so on). Other such connecting means will be readily apparent to the person skilled in the art.

The wheel arrangement 620 comprises at least one wheel 625. A wheel should be understood to mean a rotatable structure that is adapted to rotate when moving along the floor or a ground surface 1000. By way of example, a wheel may comprise a pneumatic tyre, a hubless wheel, a substantially spherical ball; a caster or even a roller. Other rotatable structures suitable for use as a wheel will be well known to the person skilled in the art.

Preferably, the wheel arrangement is adapted to be coupled to a ground surface when the powered unicycle device is in an upright or vertical orientation. In some other embodiments, the wheel arrangement comes into contact with the ground surface when the powered unicycle device is angled with respect to the ground surface (i.e. leans towards the position of the auxiliary support). By way of example, the wheel arrangement may not be in contact with the ground surface when the powered unicycle is upright, but when the powered unicycle is leant (e.g. by more than 5° or possibly 10°), the wheel arrangement comes into contact with the ground surface, and the auxiliary support supporting a leaning of the user.

The suspension arrangement 630 is embodied as an elastically deformable element. The elastically deformable element is adapted to bend and flex as the powered unicycle 100 undergoes a side to side tilting as shown in FIGS 6C and 6D. The bending may, for example, be caused by the shift in user’s weight applying force to the elastically deformable member, causing the elastically deformable member to bend. In doing so, the elastically deformable element provides a resistive force to the sideways tilting of the unicycle device. This resistive force may be understood to comprise the restoring force and/or reactive force of the elastically deformable member. Put another way, a leaning of the unicycle device causes the elastically deformable element to bend, resulting in the elastically deformable element pushing back against the unicycle device.

In other words, as the unicycle device leans sideways, so the elastically deformable element flexes and supports the unicycle device. In this way, the elastically deformable element hinders or dampens the sideways tilting of the unicycle device, whilst still allowing the unicycle device to undergo tilting (i.e. tilting is not completely prevented).

Presently the elastically deformable element is formed as a quarter-elliptical leaf spring, which provide the advantage of being a simple implementation, as well as allowing the wheel to be readily positioned away from the unicycle device. In other embodiments, the elastically deformable element is shaped as an elliptic, semi-elliptic, three quarter-elliptic or transverse leaf spring. In an alternative embodiment, the elastically deformable element may be a coiled spring (e.g. a torsion spring or v-spring).

In understanding the operation of the elastically deformable element, the skilled person would appreciate that the elastically deformable element may be formed of material having a particular elastic modulus. The elastic modulus is a property of a material that is independent of the structure formed from the material. The elastic modulus may be the material’s Young’s modulus or tensile modulus so as to provide an indication of the rigidity or stiffness of the intrinsic material. Conventionally, the lower the elastic modulus, the more elastic or intrinsically deformable a material is. A stiffness of the elastically deformable element is readily understood to be the rigidity of the elastically deformable element, such that the stiffness defines to what extent an applied force is resisted by the elastically deformable element. It will therefore be apparent that the elastically deformable element may have a stiffness which permits the elastically deformable element to bend and flex with the tilting of the unicycle device, whilst providing a suitable restoring force so as to dampen the tilting of the unicycle device. By way of example, the elastically deformable element may provide a restoring force approximately equal to three quarters of the weight of the user, such that the tilting of the device is hindered.

It will be apparent that the bending and flexing of the elastically deformable element may move the wheel arrangement 620 with respect to the connecting means 610. The wheel arrangement may be substantially connected to the ground surface throughout the tilting of the unicycle device, to thereby support the unicycle device in its tilting. In other embodiments, the wheel arrangement comes into contact with the ground surface after a predetermined amount of leaning, so as to support the unicycle device after the predetermined amount of tilt.

In other words the elastically deformable member is adapted to reversibly move the wheel arrangement with respect to the connecting means. In preferable embodiment, the elastic movement is by a vertical distance of at least 3mm, preferably 5mm and even more preferably at least 10mm. In other words, the elastically deformable member should allow the wheel arrangement to move from a first position, to a second position over a distance of at least 3mm, and subsequently elastically return to the first position. In other words, the elastically deformable member displays a low plasticity.

It will be apparent that the elastically deformable member thereby reduces the rotational speed of the unicycle leaning to a side. By way of example, the elastically deformable member may reduce the speed by up to 90%, for example 75%, for example, up to 50%. Preferably, the auxiliary device reduces the rotational speed of the unicycle device leaning in the direction of the auxiliary device by at least 50%. The selection of the speed may be performed by appropriately shaping a suitably flexible material so as to have an appropriate restoring force (i.e. an appropriate spring rate).

It may be understood that the connecting means 610 acts as an anchor point for the elastically deformable element, such that the elastically deformable element may bend any flex about the connecting means. In embodiments, the connecting means may be formed as an aspect of the unicycle device, e.g. the suspension arrangement is directly connecting to a frame of the unicycle device.

The bending of the elastically deformable member may cause an angle of the wheel 625 of the wheel arrangement 620 to change relative to a ground surface. That is to say, as the unicycle device tilts, so the angle of the wheel of the wheel arrangement may be altered. Changing the angle of the wheel in this way improves the turning capabilities (i.e. turning speed and turning circle) of the unicycle device having an auxiliary support.

In other words, the camber angle of the wheel arrangement 620 may change in response to a tilting of the unicycle device 100. This may aid and improve a steering capability of the unicycle device having an auxiliary support attached thereto. The change in the camber angle may be caused by the flexing of the elastically deformable member in response to a lean of the unicycle device.

It will be apparent that in some embodiments the angle of the wheel need not change in response to a tilting or leaning of the unicycle device, but may rather remain at a substantially the same angle with respect to the ground surface (e.g. remain substantially orthogonal to the ground surface).

Preferably, when the unicycle device is in the upright position and at rest as shown in Figure 6C, at least one wheel of the wheel arrangement is angled with respect to a ground surface. In particular embodiments, the at least one wheel is angled by at least 10° with respect to the ground surface. Preferably, the at least one wheel is angled to lean towards the unicycle device. It will be apparent that at rest (i.e. when the unicycle device is in an upright position) the wheel may be angled with respect to a wheel of the unicycle device. It is herein recognized that providing an angled wheel in this way improves the steering capabilities of a unicycle device having an auxiliary support attached thereto. It is herein identified that an inwardly angled at least one wheel of the wheel arrangement (i.e. the wheel points towards the direction of the unicycle device) provides particularly advantageous steering capabilities when the angle of the wheel may be changed in response to a leaning of the unicycle device (e.g. due to the elastically deformable member bending and flexing).

In a particular embodiment, the elastically deformable element comprises polycarbonate having an elastic modulus of between 2 and 2.4 GPa. Purely by way of example, the elastically deformable element may be shaped so as to have a stiffness of around 3-5 kNm V This will advantageously allow the unicycle device to provide a preferable resistive or restoring force to the unicycle device for an average adult male, dampening the leaning of the unicycle device. It will be apparent that the stiffness of the elastically deformable element may be different for different users (e.g. a child would require a less stiff elastically deformable element than an adult).

In conceivable embodiments, the elastically deformable element is formed from at least one of the following: polycarbonate; fiberglass; flexible composite structure; and spring steel.

In some embodiments, the elastically deformable element comprises a spring adapted to undergo compression or extension so as to provide a restoring force to a leaning unicycle device. A second embodiment of an auxiliary support 700 according to the invention may be described with reference to FIGS 7A and 7B. As before, the auxiliary support comprises a connecting means 710, a wheel arrangement 720 and a suspension arrangement 730.The wheel arrangement and the connecting means are coupled together via the suspension arrangement. FIGS 7A and 7B illustrate a scenario in which the auxiliary support is connected to a unicycle device 100. In FIG 7A, the unicycle device is in an upright position, in FIG 7B, the unicycle device is in a leaning position.

The connecting means 710 may be embodied as previously described, and will not be repeated for the sake of brevity.

The wheel arrangement 720 comprises a wheel 725 adapted to rotate about an axle 726, wherein the axle is connected to the suspension arrangement at a single end. This provides a simpler implementation of the auxiliary support device, and allows for a greater footprint for the suspension arrangement, as a wheel need not be positioned beneath the suspension arrangement, but rather may be positioned to the side of the suspension arrangement.

In other embodiments, the suspension arrangement is connected to both sides of the axle 726. This may increase the reliability of the auxiliary support.

The suspension arrangement 730 comprises at least one torsion spring 735. By way of example, the suspension arrangement may comprise a first torsion spring 735 and a second torsion spring 736.

In response to the unicycle device undergoing a lean (that is shifting from an upright position as shown in FIG 7A to a leaning position as shown in FIG 7B), the suspension arrangement moves the wheel arrangement relative to the connecting means (i.e. moves the wheel relative to the unicycle device).

In preferable embodiments, the torsion springs apply a resistive or restoring force to the leaning of the unicycle device, dampening the lean of a user. The restoring force may be considered in identifying the spring rate or the torsion springs. In this way, the lean of the unicycle device is hindered or impeded. In other words, the auxiliary support provides a supplementary supporting force to the unicycle arrangement by coupling the unicycle device to a ground surface via a suspension arrangement.

As previously described, although in preferable embodiments a wheel of the wheel arrangement is in contact with the ground surface when connected to an upright unicycle, it will be apparent that a wheel of the wheel arrangement may only come into contact with the ground surface at a predetermined amount of leaning of the unicycle device. By way of example, when the unicycle device is in an upright position, a wheel of the wheel arrangement may not be in contact with a ground surface (i.e. be lifted off the ground). When the unicycle is in a leaning position, the wheel of the wheel arrangement may be brought into contact with the ground, and subsequently the auxiliary support may hinder a further leaning or tilting of the unicycle device.

As shown in the present embodiment, the arrangement of a plurality of torsion springs allows the wheel of the auxiliary support to have a substantially constant angle with respect to the ground surface, such that the angle of the wheel remains substantially the same. In other words, a camber angle of the wheel arrangement remains substantially constant for any amount of leaning of the unicycle device. In other embodiments, the arrangement of torsion springs is adapted to allow the wheel of the auxiliary support to remain substantially constant with respect to a wheel of the unicycle device. In other words, as the wheel of the unicycle device leans, so the wheel of a wheel arrangement may also lean.

By way of example, the suspension arrangement may comprise a single torsion spring adapted to allow rotation movement of the wheel arrangement about the unicycle device (i.e. about the anchor point determined by the connecting means). A spring rate of the torsion spring may define an amount of restoring or restoration force that may be provided to the unicycle device to thereby permit the auxiliary support to support a leaning of the unicycle device. A third embodiment of an auxiliary support according to the invention may be described with reference to FIGS 8 and 9. FIGS 8 and 9 each illustrate a modular auxiliary support 800, 900 wherein the suspension arrangement comprises a plurality of flexible elements connectable together so as to change the stiffness of the suspension arrangement.

With reference now to FIG 8, in an embodiment the auxiliary support 800 comprises a suspension arrangement 830 embodied as an elastically deformable element. The elastically deformable element is formed of a plurality of flexible elements 831, 832 which may be stacked so as to change a stiffness of the elastically deformable element. .

By way of explanation, we may assume that a stiffness, k, of the elastically deformable member may be approximated using the following equation:

(1) where A is the cross-sectional area of the elastically deformable member, E is the elastic modulus of the material forming the elastically deformable member and L is the length of the elastically deformable member. The stacking of multiple flexible elements adjust a cross-sectional area of the elastically deformable member, thereby changing the stiffness.

By way of example, the elastically deformable element 830 may comprise a first flexible element 831 and a second flexible element 832. The first flexible element may be connected to the wheel arrangement of the auxiliary device and be connectable to the unicycle device (i.e. comprises the connecting means). The second flexible element 832 may be connectable to the first flexible element (e.g. via a nut and bolt arrangement, a magnetic arrangement, glue and the like). Further flexible members (not shown) may be stacked on the second flexible member so as to further alter the stiffness of the elastically deformable element.

In other words, the degree to which the elastically deformable element can bend and flex may be changed and altered by adjusting a number of flexible elements from which the elastically deformable element is formed.

Put another way, the suspension arrangement may comprise a plurality of stackable flexible elements, the number of stacked flexible elements defining the stiffness of the suspension arrangement and thereby the amount of support provided by the auxiliary support. Any number of flexible elements may be provided (i.e. 2 or more). In some embodiments, a first flexible element may be embodied as the elastically deformable member described with reference to FIGS 6A-6B, and a further one or more flexible elements may be placed on top or below the first flexible element so as to alter a stiffness of the first flexible element.

The further one or more flexible elements may be formed from the same material as the first flexible element, or different materials so as to allow more precise selecting of the stiffness of the elastically deformable element.

With reference now to FIG. 9, in an embodiment the auxiliary support 900 comprises a suspension arrangement comprising an elastically deformable element 930 formed of a plurality of flexible elements. The plurality of flexible elements are connectable together so as to allow for extension in the length of the elastically deformable element.

With reference to equation I, it is apparent that adjusting the length of the elastically deformable element in this way will allow for adjustment of the stiffness of the elastically deformable element.

By way of example, the elastically deformable element 930 may comprise a first flexible element 931, a second flexible element 932 and a third flexible element 933. The first flexible element may comprise a connecting means 910 (for connecting the first flexible element and thereby the elastically deformable element to a unicycle device. The second flexible element may be connected to the wheel arrangement 920 of the auxiliary support.

In a first scenario, the first flexible element 931 may be connectable to the second flexible element 932 via the third flexible element 933, such that the third flexible element couples the first and second flexible elements together.

In a second scenario, the third flexible element 933 is removed, such that the first flexible element 931 directly couples to the second flexible element 932, thereby \reducing the overall length of the elastically deformable member 930. In other words, a number of flexible elements defines the stiffness of the elastically deformable member.

It will be apparent that any number of further flexible elements (i.e. one or more further flexible elements) may be positioned between the first flexible element and the second flexible elements so as to selectably define the stiffness of the elastically deformable element.

In some embodiments, a user may select a third flexible element from a plurality of possible third flexible elements (e.g. of different lengths or materials), so as to allow a user to interchange the third flexible element and thereby adjust the stiffness of the auxiliary support in this manner.

The flexible elements of the auxiliary support may be connectable together in any known connecting manner. By way of example, they may be connected together using a clipping arrangement, a magnetic arrangement and the like. In the present scenario, the flexible elements each have a complimentary shape or profiles, so as to allow ease of connection between the flexible elements.

The further one or more flexible elements may be formed from the same material as the first and/or second flexible element, or different materials so as to allow a more precise selecting of the stiffness of the elastically deformable element. A suspension arrangement of an auxiliary support according to an embodiment may be biased towards an initial or rest position, such that upon being deformed (e.g. by a user’s weight), the suspension arrangement will attempt to return to the initial position. In this way, the suspension arrangement may provide a supporting force against the user.

Although a number of embodiments of the suspension arrangement of the auxiliary support have been described, namely a flexible element and a torsion spring embodiment, it will be appreciated that the concepts described herein may relate to other embodiments of the suspension arrangement. By way of example, the suspension arrangement may comprise one of: a torsion spring; a leaf spring; a coil; a shock absorber; a hydraulic system; a pneumatic system; an air spring; an inflatable bag; a flexible beam; a v-spring; and a linkage arrangement. For example, in a pneumatic system, an air filled bag may resist and support a weight placed upon it, whilst undergoing a deformation.

The auxiliary support may be connectable to any aspect of the unicycle device 100. By way of example, the auxiliary support may be connected to an aspect of the drive arrangement 135, or to afoot platform 165. In other examples, the auxiliary support is connected to a casing of the unicycle device. Preferably, the auxiliary support is connected to a frame of the unicycle device, and preferably connected to an element of the frame positioned below a foot platform (i.e. between a foot platform and a ground surface).

In preferable embodiments, the wheel arrangement does not come into direct contact with the unicycle device when the unicycle device undergoes a lean or tilt. This allows the wheel of the wheel arrangement to roll freely, and not having a braking effect caused by the unicycle device coming into contact with the wheel arrangement. Such an embodiment may be carried out by shaping the suspension arrangement so as to position the wheel in an appropriate arrangement.

Preferably the wheel is positioned to directly below the foot platform, such that a user may readily mount and dismount from the unicycle device (that is, readily place a foot to the side of the foot platform).

In some embodiments, the auxiliary support is formed as an aspect of the unicycle device. In embodiments, the connecting means may be an aspect of the unicycle device (e.g. a welded joint or a nut and bolt arrangement).

It should be understood that, in use, the wheel arrangement of the auxiliary support is adapted to move relative to the unicycle device, such that in response to a leaning of the unicycle device, the wheel arrangement may move relative to the device to continue supporting said device, whilst allowing the device to undergo a degree of leaning.

There may be provided a plurality of auxiliary supports, each adapted to support the unicycle device in response to a lean in a particular direction. By way of example, there may be provided a first auxiliary support adapted to support a leaning to a first side of the unicycle device (e.g. leaning to the left), and a second auxiliary support adapted to support a leaning to a second side of the unicycle device (e.g. leaning to the right).

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An auxiliary support for a powered unicycle device, the auxiliary support comprising: connecting means adapted to connect the auxiliary support to the powered unicycle device; a wheel arrangement comprising at least one wheel; and a suspension arrangement coupled between the connecting means and the at least one wheel, and adapted to permit the wheel arrangement to move with respect to the connecting means.

2. The auxiliary support of claim 1, wherein the connecting means is adapted to connect to a frame of the powered unicycle device.

3. The auxiliary support of any preceding claim, wherein the suspension arrangement comprises an elastically deformable element.

4. The auxiliary support of claim 3, wherein the elastically deformable element comprises a flexible elongate member.

5. The auxiliary support of any of claims 3 or 4, wherein the elastically deformable member is adapted to elastically move the wheel arrangement with respect to the connecting means by a vertical distance of at least 3mm.

6. The auxiliary support of any of claims 3 to 5, wherein the elastically deformable element is adapted to have a variable stiffness, and wherein the auxiliary support comprises an adjustment arrangement adapted to adjust the stiffness of the elastically deformable element.

7. An auxiliary support according to any of claims 3 to 6, wherein the elastically deformable element comprises a plurality of flexible element connectable together, wherein the plurality of flexible elements cooperate to define an overall stiffness of the elastically deformable element.

8. The auxiliary support of claim 7, wherein the flexible elements are adapted to be stackable, such that the length of the elastically deformable element is substantially the same for any number of flexible elements.

9. The auxiliary support of claim 7, wherein the flexible elements are connectable end-on-end, such that the length of the flexible element increases with the number of flexible elements.

10. The auxiliary support according to any preceding claim, wherein, in use, the auxiliary support is adapted to contact a ground surface when connected to the unicycle device.

11. The auxiliary support of any preceding claim, wherein the suspension arrangement comprises an elastic material formed of polycarbonate wherein optionally the elastically deformable element is formed as a quarter elliptical leaf spring

12. The auxiliary support of any preceding claim, wherein, when connected to the powered unicycle device and at rest, at least one wheel of the wheel arrangement is angled with respect to a wheel of the powered unicycle device.

13. The auxiliary support of any preceding claim wherein the angle of at least one wheel of the wheel arrangement with respect to a wheel of the powered unicycle device is adapted to alter in response to a leaning of the powered unicycle device.

14. The auxiliary support of any preceding claim, wherein the wheel arrangement comprises at least one wheel mounted on an axle, and wherein the suspension arrangement is connected to only a single end of the axle.

15. The auxiliary support of any preceding claim, wherein the suspension arrangement comprises at least one of: a torsion spring; a leaf spring; a coil; a shock absorber; a hydraulic system; a pneumatic system; an inflatable bag; a flexible beam; a v-spring and a linkage arrangement.

16. A powered unicycle comprising: a single primary wheel adapted to rotate about a primary axis of rotation; a balance control system adapted to maintain fore-aft balance of the unicycle device by controlling rotation of the primary wheel; a foot platform for supporting a user of the unicycle device; and an auxiliary support according to any preceding claim.