CENTRAL WHEEL STRUCTURE AUTO-BALANCING DEVICE

An ergonomic and rider-friendly auto-balancing personal transportation device. The device may have a central wheel structure with one or more tires and deployable foot platforms located on both sides of the central wheel structure. The platforms may be linked to a handle, such that lifting the handle retracts the foot platforms and releasing the handle may deploy them. The tire size and platform size may be set so that the device is easy to step on to, and the distance to ground when dismounting is reduced. Dual tire and single wider tire embodiments. Embodiments that allow different or multiple rider orientations are also disclosed, as are other features and embodiments.

FIELD OF THE INVENTION

The present invention relates to personal transportation devices and, more specifically, to compact auto-balancing devices that may afford such features as deployable foot platforms, a lightweight ergonomic shape and foot platforms that may be oriented differently with respect to the line of direction of travel, among other features.

BACKGROUND OF THE INVENTION

The prior art of self-balancing personal transportation devices includes the Segway, described in U.S. Pat. No. 6,302,230 for Personal Mobility Vehicles and Methods, issued to Kamen et al. More recently, the prior art includes the Solowheel, described in U.S. Pat. No. 8,807,250 (the '250 patent) for a Powered Single-Wheeled Self-Balancing Vehicle for Standing Use, issued to Shane Chen, the inventor herein, and which is hereby incorporated by reference as though disclosed in its entirety herein.

The prior art includes self-balancing personal transportation devices. One is the Segway, described in U.S. Pat. No. 6,302,230 for Personal Mobility Vehicles and Methods, issued to Kamen et al., and another is the Solowheel, described in U.S. Pat. No. 8,807,250 for a Powered Single-Wheeled Self-Balancing Vehicle for Standing Use (the '250 patent), issued to Shane Chen, the inventor herein. The '250 patent is hereby incorporated by reference as though disclosed in its entirety herein.

While devices such as those disclosed in the '250 patent are an advancement in the art of transportation devices, they may have disadvantages aspects. One is that they are relatively bulky and heavy, making them somewhat unattractive and difficult to carry or stow, for example, if used in commuting where a person must carrying or stow the device when not in use, i.e., on a bus or train, or in the office. Thus, a need exists for a lighter-weight and/or better form factor device.

Furthermore, larger devices may be more intimidating to a new user, effectively creating a bar to use. A need exists for a lower profile device that is easier to step on or off of and that has a sleeker, less intimidating appearance. A more stable device is also sought.

A need also exists for ready retraction and deployment of foot platforms, including retraction and deployment that occur automatically or near automatically when a user picks up or sets down the device.

In addition, for embodiments having two paired wheels or a single tire structure with two tires, a need exists for pressure equalization between the tires. This would improve shock absorption, steering, turn efficiency, and stability.

Furthermore, a need exists to enhance the riding experience by allowing a rider to stand in different orientations relative to the line of travel of the device. This includes a need for foot platforms that are movable relative to the line of direction and larger platforms that provide multiple standing orientations, among other configurations.

SUMMARY OF THE INVENTION

Accordingly, it is also an object of the present invention to provide a personal transportation device with ready deployment and retraction of the foot platforms, either through a linkage mechanism or another mechanism.

It is another object of the present invention to provide a personal transportation device that has a “user-friendly” appearance and configuration so that it appears inviting and non-intimidating and is in fact easy to use, particularly for first-time and newer riders.

It is also other object of the present invention to provide a personal transportation device that has a dual tire structure with air pressure equalization and/or a laterally wide tire.

It is yet another object of the present invention to provide a personal transportation device that gives a user options in the orientation of the foot platform(s) relative to the direction of travel of the device.

These and related objects of the present invention are achieved by use of the central wheel structure personal transportation device as described herein.

The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings.

DETAILED DESCRIPTION

Referring toFIGS. 1-6, one embodiment of a self-balancing personal transportation device10in accordance with the present invention is shown. Device10operates similar to the self-balancing device(s) of the '250 patent referenced above, particularly with respect to propulsion, speed and direction of travel.

Device10may include two tires42,43mounted on a rim41(FIG. 2). This may be referred to as a “single wheel structure.” In the embodiments ofFIGS. 13 and 17below, a single tire may be provided on a rim, and this may also be referred to as a “single wheel structure.” The term “single wheel structure” as used herein refers to one or more tires mounted to a single rim, or to multiple rims that are coupled together so as to move at the same speed and direction.

As shown in phantom lines inFIG. 3, a gyroscopic position sensor52, electronic control circuit57and a hub motor55are preferably provided. The position sensor may sense fore-aft position and the control circuit preferably drives hub motor55(which in turn drives rim41) towards fore-aft balancing of the device based on the sensed fore-aft position. Sensor52may also sense side-to-side (or lateral) tilt. Control circuit57may adjust speed or other parameters based on a sensed sideways tilt, for example, slowing the device during a turn. Electronic control for a self-balancing single wheel structure vehicle is known in the art.

Device10may have two foot platforms20,30. These are preferably mounted to a frame or housing12in such a manner that they may be moved between a deployed or in-use position and a folded or stowed position. InFIGS. 1-5, they are shown in the in-use or deployed position and, inFIG. 6, they are shown in the stowed position.

A transport handle14may be provided and, in the embodiment ofFIGS. 1-6, may nest within housing12when not in use. A finger depression11may facilitate extraction of the handle from the nested position.

FIG. 3illustrates a tire fill valve46, whileFIG. 2illustrates a conduit47through rim41that provides air passage between the tires. The tires preferably mount to rim41in an air tight manner and air pressure between the tires is equalized through conduit47. In addition, or alternatively, an exterior conduit may be provided including one that couples to the fill valve of each tire.

The dual tire arrangement increases lateral stability over the devices of the '250 patent (regardless if air pressure is equalized or not).

Tires42,43are preferably round in lateral cross-section (for example, as shown inFIGS. 2 and 4) as compared to square-cornered tractor-trailer tires. The rounded shape allows a user to turn the device by leaning sideways (decreasing the effective radius).

Turning and stability are further enhanced with pressure equalization. For example, when a user leans laterally, the weight on one tire increases over that of the other. In a device without air pressure equalization, if a riders leans a sufficient amount, then the less weighted tire may lift off the ground. This creates a less stable riding condition than if both tires remain in contact with the ground. A benefit of air pressure equalization is that as weight increases on one tire due to a lean, air is pushed out of that tire toward the less weighted one. This reduces the radius of the more weighted tire and increases the radius of the other tire, resulting in both tires remaining in contact with the ground for a longer time period.

Furthermore, if one tire has a smaller effective radius, then the device will turn towards the side with the smaller radius, thereby increasing the turning ability or effectiveness of the device.

Referring toFIGS. 7-12, another embodiment of a self-balancing personal transportation device110in accordance with the present invention is shown. With respect to propulsion and turning, device110functions in a similar manner (and has the same or similar components) as device10described above. Device110has a handle114with two ends113,115. A first cable116is coupled between end113and foot platform120and another cable119is coupled between end115and foot platform130(cable119is obscured from view in the perspective ofFIG. 7, yet visible inFIG. 12). Ends113,115of handle114are configured to fit slidably into sheathes117,118.FIG. 12illustrates device110with the sheathes and housing removed. Cables116,119are visible.

FIGS. 7, 10 and 12illustrate device110with handle114fully let down and platforms120,130fully deployed.FIG. 9illustrates handle14fully raised and foot platforms120,130fully retracted.FIG. 8illustrates the handle partially raised and the foot platforms partially retracted.

The foot platforms120,130are preferably pivotally attached and the cables located an appropriate distance from their pivot axis123,133that a relatively short travel distance of the cable yields sufficient movement of each foot platform to move that platform from the extended to the retracted position.

Note that a mechanism such as a releasable latch or magnet or electro-mechanical actuator or hydraulic or other mechanism may be used to latch or lock the platforms in this retracted position.FIG. 8illustrates a magnet167that would attract a piece of magnetic material on foot platform120. Similar magnetic components could be used for platform130. If a magnet or latch or cam-based mechanism or the like is provided, then the platforms could be retained in the closed position and handle114nested into the housing for very compact stowage configuration, good for stowing under a bus seat or in or under a desk at work or the like.

In addition, handle114may be locked or latched in the carry or platforms retracted position. For example,FIG. 9illustrates a spring biased pin151that extends outwardly above sheath118. This may retain handle114in the raised position and thereby hold the foot platforms in the retracted position. A user pushes against the bias force of the pin while pushing down on the handle to “sink” the handle into the sheathes, thereby deploying the platforms.

It should also be recognized that while the tires142,143are driven in substantially the same direction and at the same speed (as a single wheel structure), if they were configured as separate wheels, with separate motors (and even separate controls and position sensors), the mechanisms described herein for deploying and retracting the foot platforms would still be applicable (with some tolerance added for the varying positions of the foot platforms, relative to one another, in such a two-wheel device, i.e., a device with independent platform and associated wheel control).

Referring toFIG. 13, yet another embodiment of an self-balancing personal transportation device210in accordance with the present invention is shown. Device210is similar to device10ofFIGS. 1-6, yet instead of having two individual tires mounted to a single rim structure, device210has only one tire244, albeit a wide or laterally spread tire. The width of tire244provides some of the balance features provided by two parallel tires (42,43) and some of the control provided by tire pressure equalization discussed above. The wide tire244may experience more friction with the riding surface then narrow tire(s), resulting in increased drag, faster power consumption, and less ride time between recharge (depending on speed, riding surface, and other variables).

Referring toFIGS. 15-16, perspective views of another embodiment of self-balancing personal transportation device310in accordance with the present invention is shown. Device310may operate in a manner similar to other transportation devices discussed herein, particularly with respect to propulsion and turning, etc. Device310may include foot platforms320,330, two tires342,343(which may be on a single rim or single rim structure), handle314and housing312.

The foot platforms are pivotally coupled, axis333for platform330is visible inFIG. 15.FIG. 15illustrates platforms320,330in the extended or deployed position whileFIG. 16illustrates them in the retracted or stowage position.

FIG. 15illustrates electro-mechanical actuators363and coupling arm or member364. Actuator363may include a motor that in turn moves arm364so that it moves platform330between the extended and the retracted position. A similar actuator and arm/member may be provided for platform320. In addition, other actuator mechanisms may be used, including rotary or axial actuators that are provided about axis333(and a similar axis for platform320) to move the platform between open and closed. Hydraulic (or other) actuators may also be used.

The control circuit may be configured so that a double push or sustained duration push on button361initiates the retraction of deployed platforms and vice versa. A magnet or latch or the like367may be provided as discussed above for device110.

FIG. 15illustrates that the platforms may approximate the shape of the housing312or the tires342,343, at least in part. Above the pivot axis, platform330may be curved with an arc that is substantially concentric with an analogous arc of the tires. As shown, the pivot axis of the platforms may be below the axis of rotation of tires342,343.

FIGS. 15-17also show that the foot platforms may have an outer edge that is shaped at least in part with a curve, and the maximum distance of the curve from the wheel structure, when the foot platform is deployed, is substantially aligned, when view from above, vertically, with the center of the wheel structure (and the axis of rotation thereof).

Without departing from the present invention, the platforms may have an arc or curve that is not concentric with the axis of rotation of the tires, having, for example, a center that is below or otherwise positioned with respect to the tire axis of rotation, or simply having a different shape, curved or not. Similarly, the platforms may have a principal arc that has a radius that is 0-25% of the radius of the tire, or more preferably between 0-15% or 0-10% or other.

With respect to surface area of the platform relative to the surface area of the vertical plane of a tire (342or343), the platform may have a surface area that is 25% of the surface area of the tire. This platform surface area may be 10 to 20 or 25% of the tire vertical plane surface area or be a larger about. The platform may have a surface area from 25-35% of the tire plane surface area or 35-50% or more than 50%, for example from 50% or 60% or more (i.e., 60-70% or 70-80% or other), as discussed below.

For example, if the tire has a radius of 4″ (an 8″ outer diameter), and the arc of the foot platform has a radius 3.5″ (7″ long), then the wheel has a vertical plane area of 50.27 or near 50 sq. in. The area of a 3.5″ circle is 38.48 and half of that is near 20 sq. in. Since the axis333is below the rotation axis of the wheel, the platform may have a surface area of approximately 28-32 sq. in., or 30 sq. in. Thus, the platform surface area of 30 sq. in. is 60% of the vertical plane surface area of the tire, 50 sq. in.

If the platform is 6″ long, then the foot platform may have an area approximately 50% of the area of the tire's vertical plane, 25 sq. in. compared to 50 sq. in. If, however, the platform is 6″ long and the tire 10″ in diameter, then the surface area of the foot platform is approximately 30% of the vertical plane area. Further, for a 7″ long platform and a 12″ tire, the platform surface area may be approximately 25% of the vertical plane area of the tire, depending on the configuration of the tire.

FIG. 17illustrates device410that is similar to device310ofFIGS. 15-16, yet has a single wide tire444.

Other features of the embodiments ofFIGS. 15-17include that the foot platforms have their greatest width proximate that handle and wheel axle or, in other words, near their center.

In at least one embodiment of the present invention, the tires are smaller than the tire of a standard Solowheel (e.g., a device of the '250 patent).

FIG. 4shown that the length of the foot platforms is nearly as long as the tire outer diameter, the platform length being 2Y less than the outer diameter of the tire. The length of the foot platforms20,30may actually be longer than the diameter of the tire(s), for example, by 1 to 5% or even more, such as form 6-10%, or 11-15% or 16-20% or more.

Conversely, the length of foot platform20may be 1-5% less than the diameter of tire41, or 6-10%, or 11-15% or 16-20% less than the diameter of tire41, or even a further percentage less of that diameter. In one embodiment, the tires20,30may have an outer diameter of 8″ and the platforms are 7″ long (longitudinally, i.e., in the direction of travel of the device).

Referring toFIG. 14, it can be seen that the folded platforms nearly reach the same height as their associated tires, X being the difference. It should be noted that the platforms may be taller or shorter than their associated tires by the same range of percentage given above for the length of each platform relative to its tire.

With respect to other components, the battery65may be a lithium ion or other suitable battery. Suitable gyroscopic position sensors are known in the art. The device may be made of any suitable materials known for use in self-balancing vehicles.

Multiple and/or Perpendicular Platform Orientations

Referring toFIGS. 18 and 19, perspective views of two auto-balancing personal transportation devices510,610, respectively, illustrating different riding orientations, are shown. It should be recognized that device510and device610may be the same device, yet in different orientations.

FIG. 18illustrates that device510may have a first and a second foot platform520,530, respectively, similar to other devices described herein. InFIGS. 18-19, the foot platforms may be provided on the same platform member or “board”515that has an opening and fits over wheel structure.

A tire544that is preferably wide and substantially laterally stable may be provided between the foot platforms. Tire544may be driven by hub motor555. A gyroscopic or other suitable position sensor552,553may be provided with the device to indicate fore-aft lean of the platform.

FIG. 19illustrates the components ofFIG. 18, yet with the platform sections arranged substantially perpendicular to the line of direction of the device. The orientation ofFIG. 19is similar to the orientation of the devices ofFIG. 12discussed above. More specifically, with a wide tire544, device610may resemble device210(with platforms deployed) yet without the housing.

Devices510,610may, however, include a frame assembly570that includes a wheel coupled member571(shown inFIG. 19) and a platform coupled member572that may be securedly and releasably coupled to one another so that the platform sections may be released and turned 90 degrees from the orientation of the wheel (yet with the electrical connection to sensor552preserved via aligned conductors, etc.). Thus, devices510and610may be either separate devices, or they may be the same device with a frame assembly that supports movement of the platform sections (or platform board515) relative to the wheel assembly or structure. Suitable releasably securable frame members are known in the art.

Furthermore, while one wide tire is shown inFIGS. 18 and 19, it should be recognized, that two thinner tires may be provided in place of the one wide tire, for example, as two tires are provided in the device ofFIG. 11and one wide tire in the device ofFIG. 12. If two tires are provided in devices510,610, those tires may have a conduit for air pressure equalization and hence be “dual tires.”

FIGS. 20 and 21are perspective views of another embodiment of a central-wheel structure self-balancing personal transportation device710in accordance with the present invention. Device710has similar components to other devices described herein including platform sections720,730and wide wheel744(that could be two, preferably pressure equalized wheels). Device710is similar to devices510,610and includes a frame assembly770(like assembly570) that allows the platforms sections to move relative to the wheel arrangement and be re-secured in a position approximately 90 degrees different. In contrast to devices510,610, device710includes a housing712and handle714. Frame assembly770(seeFIG. 20) preferably includes a coupling member (771) connected to the wheel structure and a coupling member772connected to the platforms, with member771fitting into and being obscured by coupling member772.

Referring toFIG. 22, yet another embodiment of a central-wheel structure self-balancing personal transportation device810, in accordance with the present invention is shown. Device810is similar to device710, yet instead of a square or rectangular housing, the housing812of device810may be more sleek or streamline and include curves.FIG. 22illustrates that the housing may have a tilted section811that is reasonably flat or straight and may be complementary with the flatter top of the platform sections. Other portions813of the housing may be more curved.

The platform sections820,830may have curved tips881that may resemble the curved ends of a snow board or the like. It may be an effective training tool for snowboard riding. The curve of the tips may match the curve of the curved housing portions813.

Device810may include a handle814that is more diminutive than that of device710. The handle may be turnable (and releasably turnable) to give the user options for the position in which they carry the device (to save on arm exhaustion during long carries). The handle may slide into the housing and be flush therewith during use. This may or may not be a telescoping arrangement. As discussed elsewhere herein, there may be one wide tire or multiple parallel tires842,842, preferably with an air pressure equalizing arrangement.

Though covered by housing812, device810preferably has a frame assembly that allows the housing and platform sections to be released and re-secured to the wheel assembly in a position approximately 90 degrees from that shown inFIG. 22, so that a rider has the option to ride the device standing perpendicular to the line of travel or substantially parallel with (i.e., facing) it.

FIG. 23illustrates a supplemental platform925that may be mounted onto a central-wheel structure self-balancing personal transportation device910. Device910may be similar to devices10,110described above or other herein. Like those devices it has two platform sections920,930, a housing912, a handle914and other related components.

Supplemental platform925may have supplemental foot platforms sections920′,930′. A frame935may be provided with the supplemental platform for support and to aid in releasable secure attachment to the original foot platform sections or the housing. For example, four mechanical coupling members936may be provided under frame935and couple one each to the front and back of each foot platform9230,930(only one is shown, in dashed lines). Supplemental platform925provides a cost effective manner of allowing device910(or10or110), do be ridden parallel with or perpendicular to the line of direction of travel.

FIGS. 24A-24Dillustrate another embodiment of a central-wheel structure self-balancing personal transportation device1010in accordance with the present invention. Device1010is similar to device210ofFIG. 12and other devices. Device1010illustrates linkage between the platform sections1020,1030and the handle1014in a device having a wide tire1044. Rods, shafts, levers, or other mechanical components may be provided within housing1012and connect the foot platforms to handle1014such that further upward movement of handle1014begins retraction the foot platforms.

Referring toFIG. 25, another embodiment of a central wheel structure auto-balancing device1110in accordance with the present invention is shown. Device1110preferably includes an auto-balancing wheel assembly or structure1150that includes tire1144and is similar, for example, to the wheel structures ofFIGS. 18-19and tire544and hub motor555. InFIG. 25, tire1144is positioned for movement generally in a line from left to right or vice versa across the page. A rider standing on locations A and B would be parallel with (facing) that line of travel, while a rider standing at locations C and D would be perpendicular.

Device1110may include a broad platform that allows a rider to stand at different orientations without moving or rotating the foot platforms (as discussed above for other embodiments).

A housing1112may extend over tire1144(as shown), while one or more positions sensors1152(preferably gyroscopic sensors) may be provided to detect the pitch of platform1115.

While a thicker platform shape is shown inFIG. 25, platform1115may be thinner and resemble a saucer or planetary ring, like “Saturn.” A handle opening may be provided in or through that ring for easy carry, for example, handle1114. Alternatively, a handle1114′ may be mounted to or formed with the support for the platform.

The platform may alternatively be shaped like a flower, having petals, or a honeycomb cell, or a star or other. For example, platform1115may have lobes or sub-sections and they may be disposed at 90, 60, 45, 30 degrees or other, from one another.

It should be recognized that in device510ofFIG. 18(and others herein) the “position” or gyroscopic sensor is preferably placed on or with the wheel assembly (for example, proximate or under the coupling frame). This is shown with sensor553. Preferably this is done in the other embodiments with a movable platform. With the sensor coupled to the wheel assembly, the physical position of the sensor does not move when the platform changes orientation. This arrangement may be advantageous in that since the sensor position is not changing there no need to accounting for a new sensor position.