Auto-balacing transportation device with stable platform pivot axes

Abstract

An auto-balancing transportation device having a wheel structure and foot platforms that pivot between an in-use and a stowed position. The pivot axis for each platform is provided within the wheel structure so that the force exerted by a rider when stepping on a foot platform is applied to the wheel structure at a point within the wheel structure, as opposed to external to it, which is unstable and may cause the device to tip over.

Claims

1. An auto-balancing transportation device, comprising: a wheel structure having at least a first tire and a first rim to which the first tire is mounted; a motor that drives the wheel structure; first and second foot platforms that are located on opposite sides of the wheel structure and that pivot between an in-use position and a stowed position; a position sensor and a control circuit, the control circuit driving the motor towards auto-balancing the device based on data from the position sensor; a first mounting arm structure that mounts the first foot platform to a first pivot axis and a second mounting arm structure that mounts the second foot platform to a second pivot axis, the first and second pivot axes located within the envelope of the wheel structure; wherein the first rim has an inner diameter and the longitudinal length of the first foot platform is greater than that inner diameter; and wherein, when the device is vertical and in the in-use position, the level of the first foot platform is below the level of the first pivot axis and the level of the second foot platform is below the level of the second pivot axis.

2. The device of claim 1, wherein the first pivot axis is located within an envelope of the first rim.

3. The device of claim 1, wherein the wheel structure includes a second tire, and the first and second tires are arranged in parallel.

4. The device of claim 3, wherein the first tire defines a first vertical plane that touches a side of the first tire furthest from the second tire, and the second tire defines a second vertical plane that touches a side of the second tire furthest from the first tire; and wherein the first and second pivot axes are located between the first and second vertical planes.

5. The device of claim 1, wherein the first mounting arm structure includes a first pivot mount member that affords, at least in part, pivotal movement of the first foot platform between the in-use and the stowed positions, the first mounting arm structure extending outwardly from the first pivot mount member and then downwardly toward the first foot platform; and wherein the second mounting arm structure includes a second pivot mount member that affords, at least in part, pivotal movement of the second foot platform between the in-use and the stowed positions, the second mounting arm structure extending outwardly from the second pivot mount member and then downwardly toward the second foot platform.

6. The device of claim 1, wherein, in both the stowed and the in-use positions, the riding surface of the first foot platform is located outside the envelope of the first rim.

7. The device of claim 1, wherein, in both the stowed and the in-use positions, the riding surface of the first foot platform is located outside the envelope of the wheel structure.

8. The device of claim 1, wherein the first and second pivot axes are non-colinear.

9. An auto-balancing transportation device, comprising: a wheel structure having a motor that drives the wheel structure; first and second foot platforms that are located on opposite sides of the wheel structure and that pivot between an in-use position and a stowed position; a first mounting arm structure coupled to and supporting the first foot platform and a second mounting arm structure coupled to and supporting the second foot platform; a position sensor and a control circuit, the control circuit driving the motor towards auto-balancing the device based on data from the position sensor; wherein the first mounting arm structure includes a first pivot mount member that affords, at least in part, pivotal movement of the first foot platform between the in-use and the stowed positions, the first mounting arm structure extending outwardly from the first pivot mount member and then downwardly toward the top of the first foot platform; and wherein the second mounting arm structure includes a second pivot mount member that affords, at least in part, pivotal movement of the second foot platform between the in-use and the stowed positions, the second mounting arm structure extending outwardly from the second pivot mount member and then downwardly toward the top of the second foot platform.

10. The device of claim 9, wherein the wheel structure includes a at least a first and a second tire, and wherein the first and second tires define first and second wheel envelopes, respectively, and a pivot axis of the first foot platform is within the first wheel envelope and a pivot axis of the second foot platform is within the second wheel envelope.

11. The device of claim 9, wherein the first mounting arm structure and the first foot platform pivot about a first pivot axis and the second mounting arm structure and the second foot platform pivot about a second pivot axis, distinct from the first pivot axis.

12. The device of claim 11, wherein the first and second pivot axes are located within the envelope of the wheel structure and the riding surfaces of the first and second foot platforms are located outside of the envelope of the wheel structure.

13. The device of claim 9, wherein the pivot axes of the first and second platforms are non-colinear.

14. The device of claim 9, wherein the first mounting arm structure and the first foot platform pivot about a first pivot axis and the second mounting arm structure and the second foot platform pivot about a second pivot axis; and wherein, when the device is vertical and in the in-use position, the level of the first foot platform is below the level of the first axis and the level of the second foot platform is below the level of the second axis.

15. The device of claim 14, wherein the first and second pivot axes are located within the envelope of the wheel structure and the riding surfaces of the first and second foot platforms are located outside of the envelope of a rim of the wheel structure.

16. An auto-balancing transportation device, comprising: a wheel structure having at least a first tire and a rim structure to which the first tire is mounted; a motor that drives the wheel structure; first and second foot platforms that are located on opposite sides of the wheel structure and that pivot between an in-use position and a stowed position; a first mounting arm structure coupled to and supporting the first foot platform and a second mounting arm structure coupled to and supporting the second foot platform; a position sensor and a control circuit, the control circuit driving the motor towards auto-balancing the device based on data from the position sensor; wherein a first pivot axis for the first foot platform is located within the envelope of the wheel structure and a second pivot axis for the second foot platform is located within the envelope of the wheel structure; wherein the riding surfaces of the first and second foot platforms are located outside of the envelope of the rim structure; and wherein the first and second pivot axes are non-colinear.

17. The device of claim 16, wherein the riding surfaces of the first and second foot platforms are located outside of the envelope of the wheel structure.

18. The device of claim 16, wherein, when the device is vertical and in the in-use position, the level of the first foot platform is below the level of the first axis and the level of the second foot platform is below the level of the second axis.

19. The device of claim 16, wherein the first mounting arm structure includes a first pivot mount member that affords, at least in part, pivotal movement of the first foot platform between the in-use and the stowed positions, the first mounting arm structure extending outwardly from the first pivot mount member and then downwardly toward the top of the first foot platform; and wherein the second mounting arm structure includes a second pivot mount member that affords, at least in part, pivotal movement of the second foot platform between the in-use and the stowed positions, the second mounting arm structure extending outwardly from the second pivot mount member and then downwardly toward the top of the second foot platform.

20. The device of claim 16, further comprising a second tire mounted to the rim structure, and wherein the first pivot axis is within the first wheel envelope and the second pivot axis is within the second wheel envelope.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1-2 are a perspective view and a front elevation view (in a leaning position) of a prior art auto-balancing transportation device.

(2) FIGS. 3-4 are a perspective view and a front elevation view (in a leaning position) of an auto-balancing transportation device in accordance with the present invention.

DETAILED DESCRIPTION

(3) Referring to FIG. 3, an auto-balancing transportation device 110 in accordance with the present invention is shown. Similar to device 10, device 110 may include a wheel structure 120 with two tires 121,131, a first foot platform and a second foot platform 122,132, a motor (obscured from view) which drives the wheel structure, a position sensor 116 (which may be gyroscopic or other) and a control circuit 118. Wheel structure 120 may include rims 127,137 on which tires 121,131 are respectively mounted. Data from the position sensor is used by the control circuit to drive the motor towards dynamically self-balancing the device.

(4) Device 110 solves the problem of the prior art by placing the pivot axes 141,142 of the foot platforms within wheel structure 120. In the embodiment of FIG. 3, axis 142 is placed within the envelope of tire 131. Axis 141 is similarly within the envelope of tire 121.

(5) When device 110 is standing vertically on the ground, a vertical line from pivot axis 142 to the ground intersects tire 131 (and for axis 141, tire 121). Compared to the prior art, this configuration relocates the force applied to the pivot axis by the rider's weight. The location of the pivot axis inside the wheel envelope means that instead of the wheel structure experiencing the force of the rider's weight as downward torque originating from a point outside the wheel structure, the force is exerted upon the wheel structure at a point within the wheel structure. This allows the foot platform to remain fully unfolded during mount and dismount as shown in FIG. 4.

(6) Platform mounting arms 161,162 connect the platforms 122,132 to their respective axes 141,142. In FIG. 4, it can be seen that arm 162 extends from inside the wheel structure to outside of it, and then angles downward to platform 132. The drop distance of arm 162 is preferably the distance axis 142 is within the wheel structure plus a buffer. The drop distance serves to further stabilize device 110 during mounting by placing platform 131 closer to the ground. This lessens the sideways tilt of the platform, making the device more stable and makes it easier to for a rider to place their foot on the other platform 121. In addition, more rider weight is exerted on the wheel structure, reducing the risk that the wheel structure might tip over onto the rider's foot.

(7) As shown in FIGS. 3-4, arm 162 has a mount portion or member 163 that is configured for pivotal movement about axis 142, a portion 164 that extends outwardly therefrom and then a portion 165 that descends downward to the foot platform. FIG. 3 shows a protrusion extending into mount member 163 along axis 142.

(8) In different embodiments, depending on the tilt angle when mounting and dismounting the device, the location of pivot axes 141,142 may be farther inward within wheels 121,131. In general, pivot axis 141,142 may be placed at a location within the wheel structure that does not cause the foot support to fold when only one of the rider's feet is in place. The optimal pivot axis location may vary slightly from embodiment to embodiment, but will be within the wheel structure.

(9) Device 110 has left and a right vertical planes that touch the outside of tires 121,131, respectively. The pivot axes 141,142 are preferably at or within the left and right side vertical planes. To say that an axis is within the wheel structure means that it is within the volume defined by these planes and the circumferential parts of tires that comprise the wheel structure. If there is only one tire, the vertical planes touch the two outer sides of that tire.

(10) Wheel envelope refers to the volume defined the exterior of a given tire. It is the volume bounded by vertical planes touching the two sides of that tire and the outer circumferential parts of the tire.

(11) The present invention is applicable not only to devices having a single wheel structure and two tires as shown in FIGS. 1-4, but also to a variety of device types which may differ in number of wheels or wheel structures, number of tires, self-balancing or not, and other variables.

(12) While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention and the limits of the appended claims.