WO2017009612A1

WO2017009612A1 - Self-balancing powered transportation device

Info

Publication number: WO2017009612A1
Application number: PCT/GB2016/052071
Authority: WO
Inventors: Timur Artemev
Original assignee: Timur Artemev
Priority date: 2015-07-10
Filing date: 2016-07-08
Publication date: 2017-01-19
Also published as: GB201512128D0; GB2540352A

Abstract

A self-balancing powered transportation is disclosed. The transportation device comprises: a wheel (120) having an axle; a motor (155) adapted to drive the wheel; a balance control system adapted to maintain fore-aft balance of the transportation device; a foot platform (165) for supporting a user of the transportation device, wherein the foot platform is movable between a stowed position and an active position; and a lever (270) movably connected to the first foot platform such that the lever moves relative to the first foot platform as the first foot platform is moved between the stowed position and active position.

Description

SELF-BALANCING POWERED TRANSPORTATION DEVICE

Field of Invention

The present invention relates to powered transportation devices and more particularly to powered transportation devices with self-balancing functionality.

Background to the Invention

Powered self-balancing vehicles for use while standing are known. Such vehicles include two-wheeled vehicles and single-wheeled vehicles (i.e. unicycles). In a powered self-balancing transportation device, 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 self-balancing transportation device do not include a handle bar supported by a shaft. For example, United States Patent Number US8616313B2 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

According to a first aspect of the invention, there is provided a self-balancing powered transportation device, comprising: a wheel or gear having an axle; a motor adapted to drive the wheel or gear; a balance control system adapted to maintain fore-aft balance of the transportation device; a foot platform for supporting a user of the transportation device, wherein the foot platform is movable between a stowed position and an active position; and a lever movably connected to the foot platform such that the lever moves relative to the foot platform as the foot platform is moved between the stowed position and active position.

In an embodiment, the transportation device may further comprise a single, primary hubless wheel, and the wheel or gear having an axle may be a drive wheel or gear adapted to be driven by said motor and to contact the inner rim or gear of the single primary hubless wheel so as to drive rotation of the single primary hubless wheel.

There is proposed an embodiment of a self-balancing powered transportation device comprising a supporting framework for a foot platform of the transportation device which is connected to the axle of the drive wheel or gear. Embodiments therefore provide an arrangement which is adapted to direct/transfer a loading force applied to the foot platform (from a foot of a user for example) to the axle. Thus, since the axle is typically adapted to be strong (in order to withstand high/large dynamic loads or forces), the excess strength capabilities of the axle can be utilised in order to reduce the weight of a foot platform and/or the support framework. Embodiments may therefore provide a lightweight supporting arrangement that is movable between two configurations.

Embodiment employ the realisation that an axle of a self-balancing powered transportation device is typically designed to be extremely strong and have excess strength capacity for withstanding extreme loads that are beyond normal or expected dynamic loads. It is proposed the make use of the additional load/strength capabilities of such an axle by supporting a foot platform of the transportation device on the axle (via a support framework). As a result, the weight the foot platform and/or the support framework may be reduced compared to conventional designs.

There is proposed a concept of a lever or support element for maintaining the foot platform in the active position. The support element may be movable between first and second positions, wherein in the first position the support element is adapted to maintain the foot platform in the active position, and wherein the second position the support element is adapted to permit the foot platform to move between the active position and the stowed position.

The foot platform may comprise first and second foot platforms positioned on opposite sides of the wheel, and the actuator arrangement may comprise a linkage arrangement connected between the first and second foot platforms, the linkage arrangement being adapted to move the first and second foot platforms between the stowed position and active position. Further, the linkage arrangement comprises a substantially inextensible tie element connected between the first and second foot platforms. The actuator arrangement may further comprise a connecting element connected between the first foot platform and the tie element. Also, the connecting element may comprise the lever movably connected to the first foot platform such that the lever moves relative to the first foot platform as the first foot platform is moved between the stowed position and active position. The lever may comprise first and second rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first and second rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the first foot platform is moved between the stowed position and active position.

Embodiments may comprise an actuator arrangement coupled to the foot platform and adapted to move the foot platform between the stowed position and active position, wherein the actuator arrangement comprises: a telescoping actuator adapted to move between an extended and retracted configuration so as to move the foot platform between the stowed position and active position. Thus, there may be proposed a self-balancing powered transportation device comprising a telescoping actuator that is adapted to move a foot platform of the transportation device between a stowed position and an active position. Embodiments may therefore provide an arrangement for moving a foot platform of a self-balancing powered transportation device between two positions or configurations. Telescoping actuators are specialized linear actuators that may be used where space restrictions exist, mainly because their range of motion can be many times greater than the retracted (or unextended) length of the actuating member. A form of telescoping linear actuator is made of concentric tubes of approximately equal length that extend and retract like sleeves, one inside the other, such as a telescopic cylinder. Telescopic cylinders are a special design of hydraulic, electric or mechanical cylinders which provide a long output travel from a compact retracted length. Typically, the collapsed length of a telescopic cylinder may be 20 to 40% of the fully extended length depending on the number of stages. Some telescoping units may be manufactured with retracted lengths of under 15% of overall extended unit length. Thus, employment of a telescoping actuator may help to reduce the size (e.g. thickness, length or vertical profile) of the actuator arrangement when the foot support is in either configuration, thereby allowing the transportation device to have a slim body. In other words, embodiments may employ a telescoping actuator which helps to reduce the size and/or width of the transportation device. A proposed actuator arrangement may thus help to ensure that sufficient leverage can be generated to move the foot platform, while maintaining a slim-line design to ensure the transportation device can meet predetermined size, weight, height or volume requirements.

The telescoping actuator may, for example, further comprise: one or more hydraulic, electric or mechanical actuators adapted to move the telescoping actuator between the extended and retracted configuration.

Embodiments may therefore employ a simple and cheap arrangement that can be driven so as to move the foot platform between predefined configurations. Embodiments may therefore be adapted to cater for various configurations of foot platforms, such as: single foot platforms that extend through the transportation device so as to protrude from either side; or separate foot platforms (provided for each foot of a user) situated on opposite sides of the transportation device. The telescoping actuator may comprise a telescopic cylinder formed from a plurality of nesting, telescoping sections that are adapted to extend and retract like sleeves, one inside another, so as to move between an extended and retracted configuration. Further, the plurality of nesting, telescoping sections may comprise: a first, hollow, tube-like section having internal and external walls and elongated on a central axis between first and second ends, the internal wall of the first section defining a first, helical thread extending between the first and second ends; and a second cylindrical section positioned at least partially within said first section, having an external wall and elongated on said central axis between third and fourth ends, the external wall of the second section defining a second, helical thread extending between the third and fourth ends, wherein the first and second threads are mutually engaged for relative axial movement of the first and second sections in response to relative rotation thereof, and wherein the telescoping actuator comprises an electric or mechanical actuator adapted to effect relative rotation of the first and second sections to produce said relative axial movement thereof between the retracted configuration, wherein the first and second sections are concentrically arranged, and the extended configuration, wherein the first and second sections are tiered. Thus, an embodiment may employ a motor to drive movement of the nesting, telescoping sections which, in turn, cause the foot platform to move between the stowed position and active position. The motor may be controlled so that movement of the foot platform is activated and/or prevented according to predetermined conditions.

Embodiments may therefore employ an axially extensible and retractable mechanism including a plurality of mutually telescoping, threaded members wherein the design is optimised for moving a foot platform between predefined configurations. They may therefore be provided a retractable foot platform arrangement which can be positioned at any angle between 0 to 180 degrees from a vertical axis (wherein a ground supporting surface upon which the transportation device is situated typically extends generally horizontally, e.g. approximately 90 degrees when under the weight of a user. The axially extensible and retractable telescoping actuator may thus comprise a plurality of nested, helically threaded segments.

Nested, telescoping structures may therefore be provided wherein relative axial movement of a plurality of sections is provided by mutually engaged, helical screws. Such structures include tubular members having external threads over their entire length engaged with internal threads extending for a portion of the length of the circumferentially adjacent member. The threaded, tubular members may be surrounded by non-rotatable, unthreaded, telescoping sections which are axially movable with the threaded members between their relatively extended and retracted positions. Such a nested, telescoping structure may be referred to as a screwjack.

In an embodiment, the telescoping actuator structure may be movable between relatively extended and retracted positions by relative rotation of threadably engaged members with improved means for effecting electrical connection to a payload (such as a foot platform) supported upon and movable with the telescoping actuator structure. Thus, there is proposed a screw-type, axially extensible and contractable actuator structure including a plurality (at least two, but in most applications three or more) of hollow, cylindrical, telescoping members, all but the innermost of which are internally threaded over substantially their entire length, from one end to an internal stop means adjacent the other end. Also, all except the outermost of the telescoping members may have external threads extending from one end for a portion, in most cases less than 1/10, of the total axial length of the member. The stop means may comprise a lip extending inwardly around the end of each member opposite the end having the external threads. The lip may have an axial length on the order of that of the external threads, if desired, and engage the adjacent inner member snugly to provide lateral support and prevent buckling when the members are extended. Means may be provided to effect relative rotation of the members, thereby moving the members axially between extended and retracted positions as the external threads on each member within the outermost member travel along the internal threads of the outwardly adjacent member. Such means may comprise an electric motor mounted to effect reciprocal rotation of the outermost member and further means for restraining rotation of the inner members with respect to the outermost members. The means for restraining relative rotation may comprise conventional means such as splines, keyways, and the like, or a non-rotatable, multi-segment, telescoping structure affixed to one or more of the threaded, axially-movable elements.

In an embodiment, the telescoping actuator may have a lead screw and one or more concentric or tiered screws. Each screw may have one or more tangential interference stop features such as stop cogs. As the lead screw is rotated, it translates out of the concentric screws. As the lead screw reaches its maximum extension, a tangential interference stop feature on the lead screw tangential ly contacts a tangential interference stop feature on the concentric screw with which the lead screw is threadably engaged. Upon tangential contact, the associated concentric screw rotates in unison with the lead screw. When there are additional concentric screws, as each concentric screw reaches its maximum extension, the system of tangential contacting of tangential interference stop features causes the other concentric screws to extend out in sequential fashion. Thus, an embodiment may comprise a telescopic actuator having a lead screw and one or more concentric (when compressed/retracted) or tiered (when extended) screws. Each screw in the actuator may have either inner threads, outer threads, or both inner and outer threads. The threads can run the entire length of a screw, or can be cut only on a portion of a screw. Each screw may also have one or more tangential interference stop features, such as a stop cog. The tangential interference stop features may be positioned at any point along the length of a screw.

From a fully collapsed state, one lead screw, either innermost or outermost, may be rotated so that it translates out of the other collapsed screws of the actuator. At a certain point of the extension, a stop cog on the lead screw may tangentially contact a stop cog located on the first concentric screw. Upon tangential contact, the first concentric screw rotates in unison with the lead screw and translates out of any other concentric screws of the actuator. Upon complete extension of the first concentric screw, a stop cog on the first concentric screw may tangentially contact a stop cog on the next concentric screw. This cycle can be repeated until each concentric or tiered screw is translated outward. The telescopic actuator can be a linear drive actuator and can be used for moving a foot platform of a transportation device between two configurations.

In an embodiment, the telescoping actuator may comprise a plurality of interlocking concentric rings that are adapted to translate relative rotational movement of the rings to relative linear movement of the rings, so as to move between the extended and retracted configuration. At least one of the rings may comprise a sloped projection that is adapted to engage with an adjacent ring such that the sloped surface is adapted to urge the adjacent ring in a direction that is substantially parallel to the central axis of the relative rotational movement. The actuator arrangement may further comprise: a connecting element connected to the foot platform and movably coupled to the telescoping actuator such that the connecting element moves relative to telescoping actuator as the foot platform is moved between the stowed position and active position. The connecting element may comprise a lever movably connected to the foot platform such that the lever moves relative to foot platform as the foot platform is moved between the stowed position and active position. Furthermore, the lever may comprise first and second rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first and second rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the foot platform is moved between the stowed position and active position. In the folded configuration, an angle defined between the first and second rigid bars may be substantially equal to 0°, and, in the unfolded configuration, the angle defined between the first and second rigid bars may be substantially equal to 180°. In an embodiment, the actuator arrangement may comprise: a further telescoping actuator adapted to move between an extended and retracted configuration as the foot platform is moved between the stowed position and active position. The telescoping actuator may therefore be coupled to the first rigid bar and the further telescoping actuator may be coupled to the second rigid bar, such that the first and second rigid bars are adapted to move between the folded and unfolded configuration as the telescoping actuators move between the extended and retracted configuration.

The transportation device may further comprise: an entity presence detection system adapted to detect the presence of an entity on, at or near a part of, the powered transportation device and provide an indication of detected entity presence; and a control system adapted to control operation of the actuator arrangement based on the indication of detected entity presence from the entity presence detection system. Thus, an embodiment may provide an indication or signal which is used by a control system to alter operation of the actuator arrangement upon occurrence of one or more predetermined conditions indicating an entity (such as a user) is present or not-present on the transportation device. Such embodiments may therefore enable quick and easy deployment from an off configuration (wherein the foot platform is in a stowed position, for example) to an on configuration (wherein the foot platform is in an active position, for example). This deployment may require little or no input from the user, but instead may be automatically achieved when the user is in close proximity with, or contacts) one or more predetermined parts of the transportation device. In other examples, the deployment may be automatically achieved when the user performs one or more predetermined actions with the transportation device, such as lifting the transportation device from/to their shoulder to/from the ground. The one or more predetermined actions may be detected by an entity presence detection system, for example.

Embodiments may enable the foot platform to automatically move to a stowed configuration if the user alights or dismounts from the transportation device (e.g. by intentionally stepping off the foot platform(s) or by falling off). Embodiments may therefore facilitate multiple functions, including the provision of an automatic foot platform deployment mode, the provision of quick start-up/deployment, and the provision of an automatic-stowing safety feature. Embodiments may thus provide not only for improved user interaction, but also for improved safety and to protect the transportation device or its user.

According to another embodiment, the entity presence detection system may comprise a load sensing system adapted to determine a loading applied to at least one part of the powered transportation device. Further, the load sensing system may be adapted to determine at least one of: a deflection of the wheel axel; a compressive force applied to the wheel axel; a deflection of the at least one foot platform; a tensile force applied to the at least one foot platform; and a compressive force applied to the at least one foot platform, so as determine a loading applied to the at least one foot platform of the powered transportation device. In such embodiments, operation of the actuator arrangement may be based on a value of the loading applied to one or more of its parts. In some embodiments, the entity presence detection system may comprise a processing unit adapted to process signals in accordance with an algorithm to determine if an entity is present on, at or near a part of the powered transportation device. By way of example, such an algorithm may be adapted to determine if the signals from the drive arrangement and/or the balance control system exhibit a predetermined characteristic indicating the presence or non-presence of a user on the powered transportation device. The signals from the drive arrangement and/or the balance control system may comprise information relating to at least one of: casing orientation; inclination or angle of a part of the transportation device; value of compressive force applied to at least part of a foot platform; accelerometer data; gyroscope data; motor torque; speed of wheel rotation; and a motor drive voltage.

According to yet another embodiment, the entity presence detection system may comprise a vibration sensor adapted to detect a frequency of vibration of at least one part of the powered transportation device. The entity presence detection system may be adapted to determine the presence or non-presence of a user based on if a detected frequency of vibration of at least one part of the powered transportation device is within a predetermined range.

For the avoidance of doubt, reference to a single, primary wheel 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 transportation device in a direction during use. The single wheel 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.

Embodiments may provide a self-balancing powered transportation device that can alter the configuration of its foot platform(s), and such alteration may be driven by drive means (such as a motor or solenoid) rather than being undertaken manually. For example, the actuator arrangement may be automatically enabled or disabled to facilitate rapid and simple operation of the transportation device.

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 transportation 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;

FIG. 5 is an isometric view of the embodiment of FIG. 1 , wherein the casing is in an open configuration and the foot platforms are in a stowed configuration;

FIGS. 6A & 6B 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;

FIG. 7 is an isometric view of the embodiment of FIG. 1 , wherein the casing is in an open configuration and the foot platforms are in an active configuration;

FIG. 8 shows an actuator arrangement according to an embodiment, wherein the foot platforms are in an active configuration;

FIG. 9 shows the embodiment of FIG. 8, wherein the actuator is moving the foot platforms from an active configuration towards a stowed configuration;

FIG. 10 shows the embodiment of FIG. 8, wherein the actuator has moved the foot platforms to a stowed configuration;

FIG. 1 1 shows the telescoping actuator employed in the embodiment of

FIG. 10, wherein the telescoping actuator is in an extended configuration;

FIG. 12 shows an actuator arrangement according to another embodiment, wherein the actuator is in a retracted configuration;

FIG. 13A depicts the actuator arrangement of FIG. 12 moving from the retracted configuration towards an expanded configuration, wherein the actuator is in a retracted configuration;

FIG. 13B is a cross-sectional view of the embodiment of FIG. 13A taken along the line Z-Z of FIG. 13A;

FIG. 14A shows an actuator arrangement according to an embodiment, wherein the foot platforms are in an active configuration;

FIGS. 14B and 14C shows the embodiment of FIG. 14A, wherein the actuator arrangement is moving the foot platforms from an active configuration towards a stowed configuration; and FIG. 14D shows the embodiment of FIG. 14A, wherein the actuator arrangement has moved the foot platforms to a stowed configuration.

Detailed description

Proposed is self-balancing powered transportation device having an actuator arrangement which employs a telescoping actuator that is adapted to move a foot platform of the transportation device between a stowed configuration and an active configuration. The actuator arrangement has a small vertical thickness (or profile) when the foot platform is the stowed configuration, thereby enabling the transportation device to have a reduced size. In other words, embodiments may employ an actuator arrangement which helps to reduce the size and/or width of the transportation device.

The term vertical, as used herein, means substantially orthogonal to the generally horizontal ground surface upon which a transportation device 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 -7 show one embodiment of a powered transportation device 100. FIG. 1 shows the powered transportation device 100 with a casing 1 10 in a closed configuration so that it encases a single wheel 120. Here, the casing 1 10 is formed from a first, upper portion 1 10A that covers the top (uppermost) half of the wheel 120, and a second, lower portion 1 10B that covers the bottom (lowermost) half of the wheel 120. FIG 2 illustrates an exploded view of components internal to the casing 1 10, 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 1 10A of the casing is retained in a fixed position relative to the central axis 125, whereas the second, lower portion 1 10B of the casing is adapted to rotate about the central axis 125. Rotation of the second lower portion 1 10B 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 1 10 encloses the wheel 120 so that the outer rim 130 of the wheel 120 is not exposed. In the open configuration (shown in FIG. 5), the outer rim 130 of the wheel 120 is exposed so that it can contact a ground surface. 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, 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 define 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. 5-7, two foot platforms 165 are coupled to the second, lower portion 1 10B of the casing 1 10, 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. 5), and an active configuration, wherein the foot platforms are substantially perpendicular to the plane of the wheel (as shown in FIGS. 6-7) 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 1 10B of the casing) about the central axis 125 so as to be positioned inside (and covered by) the first, upper portion 1 1 OA 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 transportation device 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 transportation device by varying the pressure applied to various areas of the foot platforms 165. It also enables the transportation device to self-regulate its balance in the fore-and-aft plane. When not in use, the foot platforms 165 are moved to the stowed configuration and then rotated (with the second, lower portion 1 10B 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 1 1 OA of the casing).

The embodiment of FIGS. 1 -7 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 1 10, above the wheel 120, and may be used to hold the transportation device 100 above the ground, for example to enable a user to lift, carry, convey or place the transportation device 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 transportation device 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 embodiment of FIGS. 1 -7 further comprises an actuator arrangement (only partly visible in FIG. 6) coupled to the foot platforms 165 and adapted to move the foot platforms between the stowed configuration and active configuration. The actuator arrangement comprises first and second telescoping actuators 195 adapted to move between an extended and retracted configuration so as to move the foot platforms 165 between the stowed position and active position. In FIG. 6, the telescoping actuators 195 are shown in its extended configuration.

The actuator arrangement also comprises a connecting element 197 attached to each foot platform 165 and pivotally coupled to the respective telescoping actuator 195 such that the connecting element moves (e.g. rotates) relative to telescoping actuator 195 as the foot platform is moved between the stowed position and active position.

Here, the telescoping actuators 195 move between an extended and retracted configuration so as to pivotally move the foot platforms 165 between the stowed configuration and active configuration. Pivotal connection to a connection element 197 results in the coupling position between a telescoping actuators 195 and associated foot platform 165 remaining fixed as the telescoping actuators 195 expands/retracts. To affect such movement of the telescoping actuators 195, the actuator arrangement further comprises an electric actuator, such as a motor, which is adapted to drive movement of the telescoping actuators 195 when activated. Of course, it will be understood that the actuator arrangement may employ other types of actuators to move the telescoping actuators 195 between an extended and retracted configuration, such as one or more appropriately arranged hydraulic, electric or mechanical actuators.

More specifically, the telescoping actuators 195 each comprise a telescopic cylinder formed from a plurality of nesting, telescoping sections that are adapted to extend and retract like sleeves, one inside another, so as to move between the extended and retracted configuration.

The embodiment of FIGS. 1 -7 also comprises an entity presence detection system 200 adapted to detect the presence of a user. More specifically, in this embodiment, the entity presence detection system 200 comprise a proximity sensor 200 situated on each side of the first, upper portion 1 10A of the casing above the central axis 125. Each proximity sensor 200 is adapted to detect the existence of a user's leg in close proximity with the proximity sensor 200. In order to do this, the proximity sensors 200 may, for example, employ infrared reflection, ultrasonic sensing, and/or and light detection principles to detect if/when a user's leg is positioned in close proximity with the proximity sensor (e.g. contacting the first, upper portion 1 10A of the casing).

The proximity sensors 200 provide a signal indicating whether or not a user's presence it detected. This signal is provided to a control system (not shown) which is to control operation of the powered transportation device, by controlling the drive arrangement 135 for example. Based on an indication of detected user presence provided by the signal(s) from the proximity sensors 200, the control system controls operation of the powered transportation device.

Here, the entity presence detection system 200 is also adapted to trigger an activating system which moves the casing between the closed and open configurations. More specifically, the entity presence detection system 200 further comprises proximity sensors 210 incorporated into the handle 180 which are adapted to detect when a user's hand contacts the upper surface of the handle (e.g. when a user grips the handle 180). When one of the proximity sensors 210 incorporated into the handle 180 detects a user's hand contacting the upper surface of the handle 180, it provides an activation signal which triggers the activating system which, in turn, causes the second, lower portion 1 10B of the casing to rotate about the central axis to move from the closed configuration to the open configuration. This process of rotating the second, lower portion 1 10B of the casing from the closed configuration to the open configuration is depicted by FIGS. 3-4.

Furthermore, the entity presence detection system 200 is also adapted to trigger the actuator arrangement which moves the foot platforms between the stowed configuration and active configurations. More specifically, the entity presence detection system 200 provides an activation signal which triggers the actuator arrangement which, in turn, causes the first and second telescoping actuators 195 to extend so as to pivotally move the foot platforms 165 from the stowed configuration to the active configuration. This process of outwardly folding the foot platforms 165 from the stowed configuration to the active configuration is depicted by FIGS. 5-6.

It will therefore be understood that, in this embodiment, the proximity sensors 210 in the lifting handle 180 may be used to initiate the activating system and move the casing from the closed configuration to the open configuration, and to subsequently initiate the actuator arrangement to move the foot platforms 165 from the stowed configuration to the active configuration. Thus, when a user holds the transportation device 100 by the handle, the proximity sensors 210 trigger the activating system and then the actuator arrangement. In response to this trigger, the activating system moves the casing to the open configuration (depicted in FIGS. 4 & 5) so that the lowermost portion of the wheel is exposed and can be brought into contact with a ground surface, and then the actuator moves the foot platforms 165 to the open configuration (depicted in FIGS. 6 & 7) so that they project outwardly from the side of the wheel to provide support surfaces for the feet of a user. In other words, when lifted by the lifting handle 180, the transportation device may be arranged in an open and active configuration ready for deployment (e.g. placement on a ground surface).

When the user no longer desires to use the transportation device, the user grips the lifting handle to lift the transportation device from the ground. This results in the proximity sensors 210 triggering the actuator arrangement once again which then causes the foot platforms to move from the active configuration (shown in FIGS. 6 & 7) to the stowed configuration (shown in FIGS. 4 & 5), and then subsequently causes the activating system to move the casing from the open configuration (depicted in FIGS. 4 & 5) to the closed configuration (depicted in FIG. 1 ). Although the above embodiment has been described above employing a telescoping actuators which are formed from a plurality of nesting, telescoping sections that are adapted to extend and retract like sleeves, it will be understood that other embodiments may employ other types of telescoping actuators. For example, other embodiments may employ telescoping actuators which use actuating members that act as rigid linear shafts when extended, but break that line by folding, separating into pieces and/or uncoiling when retracted. Examples of such an alternative telescoping actuator include: a helical band actuator; a rigid belt actuator; a rigid chain actuator; and a segmented spindle.

A helical band actuator is a specialized linear actuator which forms a high- capacity telescoping tubular column. The telescoping column is formed by a pair of interlocking stainless steel bands. One band has a vertical rectangular profile and the other horizontal. The vertical band spirals up on itself into a stacked helix, forming the wall of the column, while at the same time, the horizontal band interlocks the continuous spiral seam of the vertical band. When the column lowers, the bands separate and retract into two compact coils.

A rigid belt actuator, also known as a push-pull belt actuator or zipper belt actuator, is a specialized mechanical linear actuator. The actuator is a belt and pinion device that forms a telescoping beam or column member to transmit traction and thrust. Rigid belt actuators can be thought of as rack and pinion devices that use a flexible rack. Rigid belt actuators use two reinforced plastic ribbed belts, that engage with pinions mounted on drive shafts within a housing. The belts have evenly spaced load bearing blocks on the non-ribbed face. As the pinions spin, the belts are rotated 90 degrees through the housing, which interlocks the blocks like a zipper into a rigid linear form. The resulting beam or column is effective at resisting tension and compression (buckling). Because the actuating member can fold on itself, it can be stored relatively compactly in a storage magazine, either in an overlapping or coiled arrangement. The actuator is driven by an electric motor.

A rigid chain actuator, known variously as a linear chain actuator, push-pull chain actuator, electric chain actuator or column-forming chain actuator, is a specialized mechanical linear actuator. The actuator is a chain and pinion device that forms an articulated telescoping member to transmit traction and thrust. Rigid chain actuators function as rack and pinion linear actuators that use articulated racks. Rigid chain actuators use limited-articulation chains, usually resembling a roller chain, that engage with pinions mounted on a drive shaft within a housing. The links of the actuating member, the "rigid chain", are articulated in a manner that they deflect from a straight line to one side only. As the pinions spin, the links of the chain are rotated 90 degrees through the housing, which guides and locks the chain into a rigid linear form effective at resisting tension and compression (buckling). Because the actuating member can fold on itself, it can be stored relatively compactly in a storage magazine, either in an overlapping or coiled arrangement. Rigid chain actuators are generally driven by electric motors.

A segmented spindle is a specialized mechanical linear actuator. The actuator forms a telescoping tubular column, or spindle, from linked segments resembling curved parallelograms. The telescoping actuator has a lifting capacity up to 200 kg (~440 pounds) for a travel of 400 mm (~15.75 inches).

A short elongated housing forms the base of the actuator and includes an electrical gear drive and storage magazine for the spindle segments. The drive spins a helically grooved wheel that engages the similarly grooved inside face of the spindle segments. As the wheel spins it simultaneously pull the segments from their horizontal arrangement in the magazine and stacks them along the vertical path of a helix into a rigid tubular column. The reverse process lowers/retracts the column.

Turning now to FIGS. 8-1 1 , there are depicted first and second actuator arrangements according to an embodiment of the invention. The first actuator arrangement is coupled to a left 165A foot platform. The second actuator arrangement is coupled to a right 165B foot platform. The first and second actuator arrangements are adapted to move the left 165A and right 165B foot platforms, respectively, between an active position (depicted in FIG. 8) and a stowed position (depicted in FIG. 10). The first and second actuator arrangements and the left 165A and right 165B foot platforms are coupled to an axle 210 via a support framework 220. The axle 210 may be the axle of a drive wheel adapted to contact the inner rim of a hubless primary wheel. Alternatively, the axle 210 may be the axle of the single, primary wheel of a transportation device.

The support framework 220 is formed of a lightweight, rigid material (such as aluminum, titanium, carbon fiber, or other suitable metal, alloy or composite) and is adapted to provide a supporting structure for supporting the first and second actuator arrangements and the left 165A and right 165B foot platforms on the axle 210. Loading forces applied to the foot platforms (from the feet of a user for example), can then be transferred through the support framework 200 to the axle. Thus, by arranging the axle have a strong tubular or cylindrical construction, for example, the weight of the actuator arrangements, foot platforms, and/or the support framework 220 may be reduced, thereby providing a lightweight supporting arrangement that is movable between two configurations.

Each actuator arrangement comprises: a first 250 and second 260 telescoping actuators that are each adapted to move between an extended and retracted configuration; and a connecting element 270 connected to the foot platform and movably coupled to the telescoping actuators 250,260 such that the connecting element 270 moves relative to telescoping actuators 250,260 as the associated foot platform 165 is moved between the stowed position and active position.

Here, the connecting element 270 is a lever 270 movably connected to the associated foot platform 165 such that the lever moves (e.g. rotates) relative to foot platform 165 as the foot platform 165 is moved between the stowed position and active position. More specifically, the lever 270 comprises first 270A and second 270B rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first 270A and second 270B rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the foot platform is moved between the stowed position and active position.

The first telescoping actuator 250 is coupled to the first rigid bar 270A, and the second telescoping actuator 260 is coupled to the second rigid bar 270B, such that the first 270A and second 280B rigid bars are adapted to move between the folded configuration (depicted in FIG. 10) and unfolded configuration (depicted in FIG. 8) as the telescoping actuators move between the retracted and extended configuration.

In the folded configuration (depicted in FIG. 10), an angle defined between the first 270A and second 270B rigid bars is substantially equal to 0°. In the unfolded configuration (depicted in FIG. 8), the angle defined between the first and second rigid bars is substantially equal to 180°.

The first 250 and second 260 actuators are adapted to affect movement of the first 270A and second 280B rigid bars, respectively, so as to move the lever 270 between the folded and unfolded configuration. Movement of the lever 270 between the folded and unfolded configuration result in movement of the associated foot platform 165 moved between the stowed position and active position.

To do this, each telescoping actuator 250,260 further comprises an electric motor 350 which is adapted to move it associated telescoping actuator between the extended and retracted configuration.

More specifically, referring to Figure 1 1 , the first telescoping actuator 250 comprises first 300 to third 320 hollow, cylindrical elements, arranged concentrically about a central axis X. The elements 300,310,320 are illustrated with the central axis in a horizontal orientation, and the elements will be described for convenience in embodiments so oriented as having left and right ends. Although the first telescoping actuator 250 will be horizontally oriented in many practical applications, it will be understood that the invention is not limited to employment in a horizontal orientation. Indeed, it will be readily understood that the second telescoping actuator 260 is vertically oriented in this embodiment.

The first, outermost element 300 is helically threaded over its internal surface from its right end to internally projecting lip (not visible) adjacent its left end. In the illustrated embodiment, the right end of the first element 300 is provided with a circumferential gear 340. The first element 300 is rotatable (about central axis X) by an electric motor 350. More specifically, the electric motor 350 rotates a worm gear 360 which is engaged with the circumferential gear teeth 340 encircling the outer surface of the first element 300.

The second element 310 is likewise helically threaded on it internal surface from its right end to internally projecting lip (not visible) adjacent its left end. The thirds element 320 does not include such internal threads.

The second element 310 includes a structure defining an external thread extending from its right end for a portion of its length (about 5/6 in the illustrated embodiment). Likewise, the third element 320 includes a structure providing an external thread at its lower end. The external thread of the second element 310 is engaged with the internal thread of the first element 300. Thus, rotation of the first element 300 will cause relative axial movement of the first 300 and second 310 elements. Likewise, relative rotation of the second 310 and third 320 elements will produce relative axial movement of these elements. The first telescoping actuator 250 may therefore be moved between fully extended and retracted positions by relative rotation of the threaded elements 300,310,320.

The first telescoping actuator 250 is shown in FIG. 1 1 with each of the threaded elements 300,310,320 in extended relative positions. Depending on the type of mechanism used to restrain relative rotation of the threaded elements, extension and retraction may take place in any sequence.

Retraction of the elements 300,310,320 results in similar fashion by rotation of the first, outermost element 300 in the opposite direction. Continued rotation of first, outermost element 300 will result in full retraction of the first telescoping actuator 250 to the FIG. 10 position.

By way of example, use of the first and second actuator arrangements to move the left 165A and right 165B foot platforms, respectively, from an active position (depicted in FIG. 8) to a stowed position (depicted in FIG. 10) will now be described. However, to avoid unnecessary repetition, such description will only be given in respect of the first actuator arrangement and the associated left foot platform 165A. The same principle and sequence of operation apply equally to the second actuator arrangement and its associated right foot platform 165B.

For each of the first 250 and second 260 telescoping actuator, the associated electric motor 350 rotates a worm gear 360 (and thus its thread), thereby causing rotation of the circumferential gear 340 provided on the first element 300 of each of the first 250 and second 260 telescoping actuators. The first element 300 replicates the rotation of the circumferential gear 340 so as to be rotated about it central longitudinal axis. As explained above (with reference to FIG. 1 1 ), rotation of the first element 300 cause relative axial movement of the first 300 and second 310 elements, and, likewise, relative rotation of the second 310 and third 320 elements will produce relative axial movement of these elements. The first 250 and second 260 telescoping actuators are therefore moved from fully extended towards retracted positions (as depicted by arrows "A" and "B" in FIG. 9). Since movement of the first 270A and second 270B rigid bars is generally restricted to rotation about a pivotal connection P, and first 270A and second 270B rigid bars are of fixed length, the retraction of the first 250 and second 260 telescoping actuators causes the first 270A and second 270B rigid bars to rotate relative to each other from an unfolded configuration towards a folded configuration and thus forced (e.g. pulled) diagonally upwards as depicted by arrow "D" in FIG. 9). This, in turn, causes downwardly and inwardly folding movement of the foot platforms 165 as depicted by arrows "C" in FIG. 9. Rotation of the first element 300 of each of the first 250 and second 260 telescoping actuators may be continued until the first 250 and second 260 telescoping actuators are fully retracted (as depicted by arrow "A^*" in FIG. 10). By this time, the retraction of the first 250 and second 260 telescoping actuators has resulted in the first 270A and second 270B rigid bars rotating to such an extent that they are both vertically oriented and in a folded configuration (as depicted in FIG. 10). The corresponding movement of the foot platform 165A caused by such rotation or folding of the first 270A and second 270B rigid bars has then resulted in the foot platform 165A being rotated downward (e.g. inwardly folded as depicted by arrows "C^*" in FIG. 10) to such an extent that they are in the stowed position (e.g. project downwardly such that their foot supporting surfaces are positioned substantially vertically).

Reversing the direction by which the first element 300 of each of the first 250 and second 260 telescoping actuators rotates (e.g. by reversing the direction by which the motor 350 rotates the worm gear) will result in the reversing the movement of the first 250 and second 260 telescoping actuators, the first 270A and second 270B rigid bars and foot platforms. In other words, by rotating the first element 300 (and thus its thread) of each of the first 250 and second 260 telescoping actuators in the opposite direction, so that the first 250 and second 260 telescoping actuators retract (i.e. move in the opposite direction to that depicted by arrows "A" and "A^*"), the first 270A and second 270B rigid bars can be rotated relative to each other from a folded configuration towards an unfolded configuration and thus forced (e.g. pushed) diagonally downwards (in the opposite direction to that depicted by arrow "D" in FIG.9) to cause upward rotation (e.g. outwardly folding movement in the opposite direction to that depicted by arrows "C" and "C^*") of the foot platform 165A. In this way, the first 250 and second 260 telescoping actuators cause movement of the foot platform 165A from the stowed position to the active position.

The embodiment of FIGS. 8-10 may therefore be employed in a self-balancing powered transportation device to enable rapid enablement/disablement of the transportation device by being adapted to move the foot platform between an active configuration and a stowed configuration. This may be done automatically when a user dismounts from, or carries, the transportation device for example. Such automatic stowage of the foot platform may improve user experience by assisting in space spacing and/or storage of the device when a user steps off the device, for example. It may also improve device safety by altering the position of the foot platforms if a user dismounts or falls from the transportation device, for example.

It will be appreciated that variations on the telescoping actuator arrangements described above may employ other telescoping actuator arrangements and/or mechanisms. For example, in another embodiment, one end of a telescoping actuator may be slidably coupled to the underside of a foot platform via a slide mechanism. The other end of the telescoping actuator may be held in a fixed position on the body or frame of the transportation device. The slide mechanism may comprise: a track provided on the guide member; and a follower provided on the lever to move along the track as the foot platform is moved between the stowed position and active position. By way of example the follower may comprise at least one wheel pivotally connected to the lever, and rotation of the at least one wheel may be driven by a motor. In other words, a telescoping actuator may be arranged to drive a wheel along a track provided on the guide member so as to cause movement of the foot platform(s).

The embodiment of FIG. 1 1 may therefore be employed in a self-balancing powered transportation device to enable rapid enablement/disablement of the transportation device by being adapted to move the foot platform between an active configuration and a stowed configuration. This may be done automatically when a user dismounts from, or carries, the transportation device for example. Such automatic stowage of the foot platform may improve user experience by assisting in space spacing and/or storage of the device when a user steps off the device, for example. It may also improve device safety by altering the position of the foot platforms if a user dismounts or falls from the transportation device, for example. Referring now to FIGS 12-13, there is shown an actuator arrangement 400 according to another embodiment. The actuator arrangement comprises an electric motor 450, a worm gear 460, and a telescoping actuator 470 that is movable between an extended configuration and a retracted configuration. In FIG. 12 the telescoping actuator 470 is in the retracted configuration, and FIG. 13 depicts the telescoping actuator 470 moving from the retracted configuration to the extended configuration.

The telescoping actuator 470 employs a concept similar to that of a helical band actuator so as to form a high-capacity telescoping conical (or cone-like) shape when in the extended configuration. The telescoping actuator 470 is formed by a plurality of interlocking concentric bands or rings. The interlocking rings has sloped projections that engage with an adjacent ring so that rotational movement (in the vertical plane of FIGS 12-13) of one ring is translated to per linear movement a direction that is perpendicular (e.g. it the horizontal direction in FIGS. 12-13) to the plane of rotation. In other words, rotation of a ring about a central axis Y causes the sloped projections to move an adjacent ring (with which the projections are engaged) in a direction that is parallel to the central axis Y. In this way, rotation of a primary ring 472 causes the telescoping actuator 470 to expand or contract in a direction that is parallel to the central axis Y (as depicted by the arrow in FIG. 12-13 for example).

More specifically, referring, the telescoping actuator 470 comprises first 472 to fifth 480 ringed elements, arranged concentrically about a central axis Y. The elements 472,474,476,478,480 are illustrated with the central axis in a generally horizontal orientation, and the elements will be described for convenience in embodiments so oriented as having outer and inner rims/edges. Although the telescoping actuator 470 may be horizontally oriented in many practical applications, it will be understood that the invention is not limited to employment in a horizontal orientation. Indeed, it will be readily understood that the telescoping actuator 470 may be vertically oriented in practical embodiments. The first, outermost element 472 comprises three horizontally projecting sloped projections 472B spaced evenly on its side-facing (e.g. vertically- oriented) surface. In the illustrated embodiment, the circumferential surface of the first element 472 is provided with a circumferential gear 473. The first element 472 is rotatable (about central axis Y) by an electric motor 450. More specifically, the electric motor 450 rotates a worm gear 460 which is engaged with the circumferential gear teeth 473 of the first element 472.

The second element 474 is concentrically arranged inside the first element 472 and comprises a lip around its peripheral edge which overlaps the side- facing (e.g. vertically-oriented) surface of the first element 472 so that the three horizontally projecting sloped projections 472B of the first element 472 pass through and engage with respective apertures 474A formed in the lip of the second element 474. The apertures 474A are elongated and curved with a radius of curvature that is centered about the central axis Y. The apertures 474A are adapted to act as guide tracks along which the projections 472B of the first element 472 may move. As the first element 472 is rotated relative to the second element 474, the projections 472B of the first element 472 move along the apertures 474A of the second element 474 and the sloped surface of the projections 472B urge the second element 474 in a horizontal direction (as indicated by the arrow).

Similar to the first element 472, the second element 474 comprises three horizontally projecting sloped projections 474B spaced evenly on its side- facing (e.g. vertically-oriented) surface.

The third element 476 is concentrically arranged inside the second element 474 and comprises a lip around its peripheral edge which overlaps the side- facing (e.g. vertically-oriented) surface of the second element 474 so that the three horizontally projecting sloped projections 474B of the second element 474 pass through and engage with respective apertures 476A formed in the lip of the third element 476. Like those of the second element 474, the apertures 476A of the third element 476 are elongated and curved with a radius of curvature that is centered about the central axis Y. The apertures 476A are adapted to act as guide tracks along which the projections 474B of the second element 474 may move. As the second element 474 is rotated relative to the third element 476, the projections 474B of the second element 474 move along the apertures 476A of the third element 476 and the sloped surface of the projections 474B urge the third element 476 in a horizontal direction (as indicated by the arrow).

Similar to the first 472 and second elements 474, the third element 476 comprises three horizontally projecting sloped projections 476B spaced evenly on its side-facing (e.g. vertically-oriented) surface.

The fourth element 478 is concentrically arranged inside the third element 476 and comprises a lip around its peripheral edge which overlaps the side-facing (e.g. vertically-oriented) surface of the third element 476 so that the three horizontally projecting sloped projections 476B of the third element 476 pass through and engage with respective apertures 478A formed in the lip of the fourth element 478. Like those of the third element 476, the apertures 478A of the fourth element 478 are elongated and curved with a radius of curvature that is centered about the central axis Y. The apertures 478A are adapted to act as guide tracks along which the projections 476B of the third element 476 may move. As the third element 476 is rotated relative to the fourth element 478, the projections 476B of the third element 476 move along the apertures 478A of the fourth element 478 and the sloped surface of the projections 476B urge the fourth element 478 in a horizontal direction (as indicated by the arrow).

Similar to the first 472, second 474 and third 476 elements, the fourth element 478 comprises three horizontally projecting sloped projections 476B spaced evenly on its side-facing (e.g. vertically-oriented) surface.

The fifth element 480 is concentrically arranged inside the fourth element 478 and comprises a lip around its peripheral edge which overlaps the side-facing (e.g. vertically-oriented) surface of the fourth element 478 so that the three horizontally projecting sloped projections 478B of the fourth element 478 pass through and engage with respective apertures 480A formed in the lip of the fifth element 480. Like those of the fourth element 478, the apertures 480A of the fifth element 480 are elongated and curved with a radius of curvature that is centred about the central axis Y. The apertures 480A are adapted to act as guide tracks along which the projections 478B of the fourth element 478 may move. As the fourth element 478 is rotated relative to the fifth element 480, the projections 478B of the fourth element 478 move along the apertures 480A of the fifth element 480 and the sloped surface of the projections 478B urge the fifth element 480 in a horizontal direction (as indicated by the arrow).

It will therefore be understood that relative rotation of the first 472 to fifth 480 elements will produce relative axial movement of these elements in the horizontal direction (as indicated by the arrow in FIGS. 12-13. The first telescoping actuator 470 may therefore be moved between fully extended and retracted positions by relative rotation of the concentrically arranged ring elements 472,474,476,478,480.

The telescoping actuator 470 is shown in FIG. 12 in a retracted configuration. Depending on the type of mechanism used to restrain relative rotation of the concentrically arranged ring elements 472,474,476,478,480, extension and retraction may take place in any sequence.

The telescoping actuator 470 is then shown in FIG. 13 moving from the retracted configuration towards an expanded configuration.

Turning now to FIGS. 14A-14D, there are depicted first and second actuator arrangements according to another embodiment of the invention. The first actuator arrangement is coupled between the left 165A and right 165B foot platforms. The second actuator arrangement is coupled between the right 165B and left 165A foot platforms. The first and second actuator arrangements are adapted to move the left 165A and right 165B foot platforms, respectively, between an active position (depicted in FIG. 14A) and a stowed position (depicted in FIG. 14D). The first and second actuator arrangements and the left 165A and right 165B foot platforms are coupled to an axle 210 via a support framework 220. The axle 210 may be the axle of a drive wheel adapted to contact the inner rim of a hubless primary wheel. Alternatively, the axle 210 may be the axle of the single, primary wheel of a transportation device.

The support framework 220 is formed of a lightweight, rigid material (such as aluminum, titanium, carbon fiber, or other suitable metal, alloy or composite) and is adapted to provide a supporting structure for supporting the first and second actuator arrangements and the left 165A and right 165B foot platforms on the axle 210. Loading forces applied to the foot platforms (from the feet of a user for example), may be transferred through the support framework 200 to the axle 210. Thus, by arranging the axle 210 to have a strong tubular or cylindrical construction, for example, the weight of the actuator arrangements, foot platforms, and/or the support framework 220 may be reduced, thereby providing a lightweight supporting arrangement that is movable between two configurations.

Each actuator arrangement comprises a flexible elongate tie element 500 and a connecting element 270 connected to a respective foot platform and movably coupled to the flexible elongate tie element 500 such that the connecting element 270 moves as the associated foot platform 165 is moved between the stowed position and active position. More specifically, the flexible elongate tie element 500 has a row of teeth 550 along its longitudinal length, much like a conventional plastic cable tie. Each flexible element is connected at one end to one of the foot platforms and to a connecting element 270 at the other end.

In particular, the first actuator arrangement comprises a first tie element 500A connected at one end to the underside of the right foot platform 165B and connected at the other end to a first connecting element 270 (which is connected between the left foot platform 165A and the support framework 220). The second actuator arrangement comprises a second tie element 500B connected at one end to the underside of the left foot platform 165A and connected at the other end to a second connecting element 270 (which is connected between the right foot platform 165B and the support framework 220).

Here, each connecting element 270 is a lever 270 movably connected to an associated foot platform 165 such that the lever moves (e.g. rotates) relative to foot platform 165 as the foot platform 165 is moved between the stowed position and active position. More specifically, each lever 270 comprises first 270A and second 270B rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first 270A and second 270B rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the associated foot platform is moved between the stowed position and active position.

The first tie element 500A is connected to the coupling between first 270A and second 270B rigid bars, such that the first 270A and second 280B rigid bars are adapted to move between the unfolded configuration (depicted in FIG. 14A) and folded configuration (depicted in FIG. 14D) as the first tie element 500A exerts a pushing force on the first 270A and second 280B rigid bars of the first connecting element (as indicated by the arrow labeled "F1 " in FIG. 14B). Also, when the first tie element 500A exerts a pushing force on the first 270A and second 280B rigid bars of the first connecting element (as indicated by the arrow labeled "F1 " in FIG. 14B), the connection of its other end to the right foot platform 165B results in a pulling force being applied to the underside of the right foot platform 165B (as indicated by the arrow labeled "F2" in FIG. 14B). This pulling force acts to pull the right foot platform 165B downwards from the unfolded configuration to the folded configuration.

Similarly, the second tie element 500B is connected to the coupling between first and second rigid bars of the second connecting element, such that they are adapted to move between the unfolded configuration (depicted in FIG. 14A) and folded configuration (depicted in FIG. 14D) as the second tie element 500B exerts a pushing force on the first and second rigid bars of the second connecting element (as indicated by the arrow labeled "G1" in FIG. 14B). Also, when the second tie element 500B exerts a pushing force on the second connecting element (as indicated by the arrow labeled "G1" in FIG. 14B), the connection of its other end to the left foot platform 165A results in a pulling force being applied to the underside of the left foot platform 165A (as indicated by the arrow labeled "G2" in FIG. 14B). This pulling force acts to pull the left foot platform 165A downwards from the unfolded configuration to the folded configuration.

In the folded configuration (depicted in FIG. 14D), an angle defined between the first 270A and second 270B rigid bars is substantially equal to 0°. In the unfolded configuration (depicted in FIG. 14A), the angle defined between the first and second rigid bars is substantially equal to 180°.

To do this, the actuator arrangement comprises an electric motor 450 and a worm gear 460. More specifically, the electric motor 450 rotates a worm gear 460 which is engaged with the teeth 550 provided along the length of the flexible elongate tie elements 500A and 500B. Rotation of the worm gear 460 thus causes linear movement of the tie elements 500A and 500B, thus results in each of the tie elements 500A and 500B pulling or pushing on connecting element at one end and pushing or pulling on the underside of a foot platform at the other end. Each tie element 500 is therefore adapted to provide a pulling or pushing force for moving both of the foot platforms simultaneously. Further, the opposite arrangement of the tie elements 500A and 500B means that they act in cooperation to simultaneously provide both a force for moving a connecting element of a foot platform 165 and a force for moving the foot platform 165. For example, as the connecting element 270 of the left foot platform 165A is pushed by force F1 from the first tie element 500A, the underside of the left foot platform is also pulled downwards by force G2 from the second tie element 500B. Simultaneously, the fixed length of the first tie element 500A results in it pulling the right foot platform downwards by force F2 as the connecting element of the right foot platform 165B is pushed by force G1 from the second tie element 500B.

Each actuator arrangement therefore comprises a single, substantially inextensible tie element connected between both foot platforms that simultaneously acts to provide a force which moves both platforms between an active position (depicted in FIG. 14A) to a stowed position (depicted in FIG. 14D). One end of the tie element may be adapted to provide a pulling force whilst the other end provides a pushing force.

By way of example, use of the first and second actuator arrangements to move the left 165A and right 165B foot platforms, respectively, from an active position (depicted in FIG. 14A) to a stowed position (depicted in FIG. 14D) will now be described. However, to avoid unnecessary repetition, such description will only be given in respect of the first actuator arrangement and the associated first tie element 500A. The same principle and sequence of operation apply equally to the second tie element 500B.

The associated electric motor 450 rotates a worm gear 460 (and thus its thread), thereby causing linear movement of the first tie element 500A (due to the meshing of the gear 460 with the teeth 550 provided on the first tie element 500A). The linear movement of the first tie element 500A exerts a pushing force on the first 270A and second 280B rigid bars of the first connecting element (as indicated by the arrow labeled "FT in FIG. 14B). Also, the connection of its other end to the right foot platform 165B results in a pulling force being applied to the underside of the right foot platform 165B (as indicated by the arrow labeled "F2" in FIG. 14B). This pulling force acts to pull the right foot platform 165B downwards from the unfolded configuration to the folded configuration.

Since movement of the first 270A and second 270B rigid bars is generally restricted to rotation about a pivotal connection P, and first 270A and second 270B rigid bars are of fixed length, the first tie element 500A causes the first 270A and second 270B rigid bars to rotate relative to each other from an unfolded configuration towards a folded configuration (as depicted by arrow "F1 " in FIG. 14B).

Rotation of the worm gear 460 until movement of the retraction of the first tie element 500A has resulted in the first 270A and second 270B rigid bars rotating to such an extent that they are both substantially vertically oriented and in a folded configuration (as depicted in FIG. 14D). The corresponding movement of the foot platform 165A caused by such rotation or folding of the first 270A and second 270B rigid bars has then resulted in the foot platform 165A being rotated downward (e.g. inwardly folded as depicted in FIG. 14D) to such an extent that they are in the stowed position (e.g. project downwardly such that its foot supporting surface is positioned substantially vertically).

Reversing the direction by which the first tie element 500A moves (e.g. by reversing the direction by which the motor 350 rotates the worm gear) will result in the reversing the movement of the first 270A and second 270B rigid bars and foot platforms. In other words, by moving first tie element 500A in the opposite direction, the first 270A and second 270B rigid bars can be rotated relative to each other from a folded configuration towards an unfolded configuration to cause upward rotation of the foot platform 165A. In this way, the first tie element 500A causes movement of the foot platform 165A from the stowed position to the active position.

It is noted that the embodiments described above include two (e.g. left and right) foot platforms. It is to be understood that proposed embodiments need not be restricted to being employed to move two foot platforms, but may instead be employed to move only a single foot platform (that is connected to the lever for example). Indeed, self-balancing powered transportation devices having a single foot platform that extends through the transportation device so as to project from either side are already available, and by way of example, a telescoping actuator may be connected to the single foot platform so that extension/retraction of the telescoping actuator is accompanied by rotation of single foot platform between two positions. In an alternative embodiment, there may be provided a support element for maintaining the foot platform in the active position. The support element may, for instance, be movable between first and second positions, wherein in the first position the support element is adapted to maintain the foot platform in the active position, and wherein the second position the support element is adapted to permit the foot platform to move between the active position and the stowed position. For example, the support element may comprise a block of solid material that can be moved (or even removed) so as to enable it to be manipulated or positioned to be between (e.g. sandwiched) a support framework and the foot support/platform. By way of another example, the support element may comprise a wedge-like element that it movable so as to alter a distance or separation between parts of the transportation device.

It may be understood that in preferable embodiments, the support element comprises a lever adapted to move with respect to the foot platform as the foot platform is moved between the stowed and active positions. It may be understood that movement of the lever causes a movement of the foot platform, so as to move the foot platform between the active and the stowed configurations.

In some embodiments, movement of the foot platform and/or lever is performed by an actuating arrangement (e.g. a worm drive or a telescopic actuator). In some embodiments, it may be considered that the lever supports the foot platform(s) in the active position, such that the lever may be considered to be a support element.

Accordingly, while specific embodiments have been described herein for purposes of illustration, various modifications will be apparent to a person skilled in the art and may be made without departing from the scope of the invention.

For example, a telescoping actuator according to an embodiment may or may not have a single physical axle. Also, the direction of movement between the retracted and extended configuration need not be linear. For example, although some embodiments may provide linear movement (and thus be referred to as linear actuator arrangements), other embodiments may provide non-linear movement that bends or curves as the telescoping actuator moves between the retracted and expanded configurations for example.

Although examples have been shown as having actuator arrangements that cause a foot platform or support to fold inwards and/or downwardly, in other examples an actuator arrangement may be arranged to cause a foot platform or support to fold outwards and upwardly.

Further, although embodiments have been described as employing single concepts or components for detecting the presence of a user on, or at part of, a transportation device, it should be understood that embodiment may employ one or more combinations of such concepts or components. A proximity sensor may therefore be employed in conjunction with a vibration sensor, and the signal provided by these sensors may be used in isolation (for altering transportation device operation in different ways for example), or may be used together (for confirming a signal from one of the sensors for example).

Also, a telescoping actuator may comprise any suitable arrangement for affecting or driving movement of a foot platform. For example, embodiments may comprise one or more hydraulic, electric or mechanical actuators adapted to move the coupling telescoping actuator between an extended and retracted configuration.

It is furthermore noted that although the illustrated structures include three or four threaded elements it is clear that any of these structures could be built to incorporate any practical number of extendable/retractable elements using the basic design concepts illustrated.

It will be apparent that some embodiments do not comprise an actuating element or actuator arrangement adapted to move the foot platform(s), rather movement of the foot platforms may be effected by a user of the device (i.e. a manual movement). By way of example, a user may manually raise and lower the foot platform(s) by directly contacting the foot platform(s) (e.g. using a foot or hand) and causing a movement between the open and closed configuration.

Conceivably, a user may manually depress, maneuver or control the lever, a button or a secondary lever so to cause a corresponding movement in the foot platform(s). By way of example, a user may release the lever, (e.g. move the lever from a first configuration to a second configuration) so as to cause the foot platform(s) to move from an active position to a stowed position. In another examples, pressing a button or switch may cause movement of the lever (e.g. releases a lock on the lever) so as to cause movement of the foot platform(s). In yet another embodiment, a user may move a secondary lever coupled to the lever or foot platform so as to cause a movement of the lever (and thereby a movement of the foot platform(s)) or foot platform. In embodiments, the transportation device comprises a lever moveably coupled to the foot platform(s), such that the lever moves relative to the foot platform as the foot platform is moved between the stowed position and active position. More specifically, a lever may comprise first and second rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first and second rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the associated foot platform is moved between the stowed position and active position.

It will be apparent that a user may cause a rotation of the first and second rigid bars relative to one another (e.g. by manually moving one of the bars, or pressing a button that causes a movement of at least one of the bars), so as to cause the foot platform to move between the stowed and active positions.

In other embodiments, rotation of the first and/or second rigid bars about one another (to cause a movement in the foot platform(s)) is performed by an actuator arrangement, such as a worm drive or telescoping actuator. 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. A single processor or other unit may fulfill the functions of several items recited in the claims. 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 . A self-balancing powered transportation device, comprising:

a wheel or gear having an axle;

a motor adapted to drive the wheel or gear;

a balance control system adapted to maintain fore-aft balance of the transportation device;

a foot platform for supporting a user of the transportation device, wherein the foot platform is movable between a stowed position and an active position; and

a lever movably connected to the foot platform such that the lever moves relative to the foot platform as the foot platform is moved between the stowed position and active position.

2. The transportation device of claim 1 , wherein the lever comprises first and second rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first and second rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the foot platform is moved between the stowed position and active position.

3. The transportation device of claim 2, wherein, in the folded configuration, an angle defined between the first and second rigid bars is substantially equal to 0°, and wherein, in the unfolded configuration, the angle defined between the first and second rigid bars is substantially equal to 180°.

4. The transportation device of any preceding claim, further comprising: an actuator arrangement coupled to the foot platform and adapted to move the foot platform between the stowed position and active position.

5. The transportation device of claim 4, wherein the foot platform comprises first and second foot platforms positioned on opposite sides of the wheel,

and wherein the actuator arrangement comprises a linkage arrangement connected between the first and second foot platforms, the linkage arrangement being adapted to move the first and second foot platforms between the stowed position and active position.

6. The transportation device of claim 5, wherein the linkage arrangement comprises a substantially inextensible tie element connected between the first and second foot platforms.

7. The transportation device of claim 6, wherein the lever is connected between the first foot platform and the tie element.

8. The transportation device of claim 4, wherein the actuator arrangement comprises: a telescoping actuator adapted to move between an extended and retracted configuration so as to move the foot platform between the stowed position and active position.

9. The transportation device of claim 8, wherein the telescoping actuator further comprises:

one or more hydraulic, electric or mechanical actuators adapted to move the telescoping actuator between the extended and retracted configuration.

10. The transportation device of claim 8 or 9, wherein the telescoping actuator comprises a telescopic cylinder formed from a plurality of nesting, telescoping sections that are adapted to extend and retract like sleeves, one inside another, so as to move between the extended and retracted configuration.

1 1 . The transportation device of claim 10, wherein the plurality of nesting, telescoping sections comprises:

a first, tube-like section having internal and external walls and elongated on a central axis between first and second ends, the internal wall of the first section defining a first, helical thread extending between the first and second ends; and a second cylindrical section positioned at least partially within said first section, having an external wall and elongated on said central axis between third and fourth ends, the external wall of the second section defining a second, helical thread extending between the third and fourth ends,

wherein the first and second threads are mutually engaged for relative axial movement of the first and second sections in response to relative rotation thereof,

and wherein the telescoping actuator comprises an electric or mechanical actuator adapted to effect relative rotation of the first and second sections to produce said relative axial movement thereof between the retracted configuration, wherein the first and second sections are concentrically arranged, and the extended configuration, wherein the first and second sections are tiered.

12. The transportation device of claim 8 or 9, wherein the telescoping actuator comprises a plurality of interlocking concentric rings that are adapted to translate relative rotational movement of the rings to relative linear movement of the rings, so as to move between the extended and retracted configuration.

13. The transportation device of claim 12, wherein at least one of the rings comprises a sloped projection adapted to engage with an adjacent ring such that the sloped surface is adapted to urge the adjacent ring in a direction that is substantially parallel to the central axis of the relative rotational movement.

14. The transportation device of any of claims 8 to 13, wherein the actuator arrangement further comprises:

a connecting element connected to the foot platform and movably coupled to the telescoping actuator such that the connecting element moves relative to the telescoping actuator as the foot platform is moved between the stowed position and active position.

15. The transportation device of claim 14, wherein the connecting element comprises the lever.

16. The transportation device of claim 15, wherein the lever comprises first and second rigid bars of fixed length pivotally coupled to each other at adjacent ends such that the first and second rigid bars are adapted to rotate relative to each other between a folded and unfolded configuration as the foot platform is moved between the stowed position and active position.

17. The transportation device of claim 16, wherein, in the folded configuration, an angle defined between the first and second rigid bars is substantially equal to 0°, and wherein, in the unfolded configuration, the angle defined between the first and second rigid bars is substantially equal to 180°.

18. The transportation device of claim 16 or 17, wherein the actuator arrangement comprises: a further telescoping actuator adapted to move between an extended and retracted configuration as the foot platform is moved between the stowed position and active position,

and wherein the telescoping actuator is coupled to the first rigid bar and wherein the further telescoping actuator is coupled to the second rigid bar such that the first and second rigid bars are adapted to move between the folded and unfolded configuration as the telescoping actuators move between the extended and retracted configuration.

19. The transportation device of any of claims 4 to 18, further comprising: an entity presence detection system adapted to detect the presence of an entity on, at or near a part of, the transportation device and provide an indication of detected entity presence; and

a control system adapted to control operation of the actuator arrangement based on the indication of detected entity presence from the entity presence detection system.

20. The transportation device of claim 19, wherein the entity presence detection system comprises at least one of:

one or more proximity sensors adapted to detect the existence of an entity in close proximity with the proximity sensor; a vibration sensor adapted to detect a frequency and/or amplitude of vibration of at least one part of the transportation device; and

a load sensing system adapted to determine a loading applied to at least one part of the transportation device.

21 . A powered transportation device substantially as herein described above with reference to the accompanying figures.