Two-wheeled vehicle

Abstract

A vehicle may include a board including a standing surface and being aligned with a longitudinal axis. A vehicle may include a rear wheel coupled within the vehicle toward a rear end of the board. A vehicle may include a front wheel coupled to a front end of the board via a swivel assembly. A vehicle may include the swivel assembly including a bidirectional biasing member configured to bias alignment of the front wheel along the longitudinal axis of the board.

Description

Two-Wheeled VehicleCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 557,240, filed on February 23, 2024, the disclosure of which is incorporated by reference herein in its entirety.BACKGROUND

[0002] There are many models of scooters and skateboards available today. Scooters include a deck with a forward wheel and rear wheel. Riders stand forward facing on scooters, and turn by rotating a tall handlebar connected to the front wheel. Skateboards include a deck with two sets of wheels attached below, each set of wheels coupled to a pivoting truck. Skateboards are ridden by standing wi th feet substantially perpendicular to the direction of travel and can be turned by leaning toe side or heel side.SUMMARY

[0003] In some aspects, the techniques described herein relate to a vehicle including: a board including a standing surface and being aligned with a longitudinal axis; a rear wheel coupled within the vehicle toward a rear end of the board; a front wheel coupled to a front end of the board via a swivel assembly; and the swivel assembly including a bidirectional biasing member configured to bias alignment of the front w heel along the longitudinal axis of the board.

[0004] In some aspects, the techniques described herein relate to a swivel assemblyincluding: a housing; a steer shaft operable to rotate w ithin an aperture of the housing; and a bidirectional biasing member including a first end and a second end, the first end coupled to the housing and the second end coupled to the steer shaft, the bidirectional biasing member operable to restore a rotational alignment of the steer shaft with respect to the housing.BRIEF DESCRIPTION OF THE DRAWINGS[0005JFIG. 1 depicts a left view of a tw o-wheeled vehicle being operated by a rider, according to examples described throughout this disclosure.

[0006] FIG. 2 depicts a perspective view of the tw o-w heeled vehicle, according to examples described throughout this disclosure.

[0007] FIG. 3 depicts a left view of the two- wheeled vehicle, according to examples described throughout this disclosure.

[0008] FIG. 4 depicts a top view of the two-wheeled vehicle, according to examples described throughout this disclosure.

[0009] FIG. 5 depicts a front view of the two-wheeled vehicle, according to examples described throughout this disclosure.

[0010] FIG. 6 depicts the cross sectional view A- A of the two-wheeled vehicle depicted in FIG. 4 along with a detail of a swivel assembly, according to examples described throughout this disclosure.[0011JFIG. 7 depicts an exploded view of the two-wheeled vehicle, according to examples described throughout this disclosure.DETAILED DESCRIPTION

[0012] Many models of scooters and skateboards exist in the prior art. None replicate the intuitive feeling and stability of riding a snowboard or a surfboard, however, especially when traveling at high speeds or making wide turns. Skateboards feature tilting trucks that each secure two wheels are coupled to the bottom of the skateboard. Skateboards require a lot of balance to ride and the trucks don’t feel stable at speed or when turning, however. Scooters sometimes feel more stable due to their forward foot position and handlebar, but scooters rely on handlebar engagement to turn instead of body lean.

[0013] The present Application describes a two-wheeled vehicle for transportation and recreation that is designed to be ridden on pavement and soil. FIG. 1 depicts a rider operating a two-wheeled vehicle 100, according to examples. As may be seen in the figure, the rider may stand in a sideways stance 104 on the two-wheeled vehicle 100, similar to a snowboard, skateboard, or surfboard posture. The two-wheeled vehicle includes two wheels positioned at opposing ends of the board. The front wheel is coupled to the board via a swivel assembly that allows the wheel to rotate left and right (depicted in FIG. 2) with respect to the board, thereby enabling the two-wheeled vehicle to be steered by leaning. With the sideways stance 104 and the swivel assembly, the rider initiates turns by leaning the board toe side or heel side, causing the front wheel to rotate in the direction of lean.

[0014] It is a technical problem that, without a handlebar, the swivel assembly of the twowheeled vehicle may over rotate, or the rotation may be hard to direct, making the twowheeled vehicle steering difficult to control.

[0015] The present disclosure describes a technical solution that includes a swivel assembly with a biasing member operable to restore the front wheel back into alignment with the board, for example when the rider is no longer initiating a turn, creating a more stable and smooth steering experience that feels much like carving on a snowboard. The present disclosure describes a further technical solution of a swivel assembly with a damping member operable to remove the sensation of vibrations at speed and / or to prevent the swivel assembly from feeling too reactive to a rider’s leaning movements. The biasing member and / or the damping member may provide for a two-wheeled vehicle with a smoother, more stable, intuitive, and safe riding experience.

[0016] The two-wheeled vehicle 100 may be driven by an electric motor positioned in, for example, the rear wheel. In examples the motor may be controlled wirelessly with a handheld motor controller 102. Other potential features of the two-wheeled vehicle 100 are further described below.

[0017] While the application describes a swivel assembly within the context of the twowheeled vehicle 100, this is not intended to be limiting. It should be understood that the swivel assembly described herein may be used with other vehicles and products as well to provide further technical advantages in other contexts.

[0018] FIG. 2 depicts a perspective view of the two-wheeled vehicle 100, FIG. 3 depicts a left view of the two-wheeled vehicle 100, FIG. 4 depicts a top view of the two-wheeled vehicle 100, FIG. 5 depicts a front view of the two-wheeled vehicle 100, FIG. 6 depicts the cross sectional view A — A of the two-wheeled vehicle 100 depicted in FIG. 4, and FIG. 7 depicts an exploded view of the two-wheeled vehicle 100, according to examples.

[0019] In the figures, it may be seen that the two-wheeled vehicle 100 may include any combination of a front wheel 202, a swivel assembly 602, a board 204, and a rear wheel 206.

[0020] In examples, the board 204 may comprise any suitable platform operable to allow a rider to stand upon a standing surface 205 on a top side of the board 204 w hen the twowheeled vehicle 100 is in an operation position with feet apart and pointed substantially perpendicular to longitudinal axis 208. The board 204 may be substantially planar, meaning that it has a length and a width defining at least one standing surface 205 that are substantially longer than a height dimension. In examples the board 204 may have a height that is uniform or within 5%, 10% or 20% of a maximum height throughout the surface area of the standing surface 205. In examples, the board 204 may be rectangular or substantially rectangular in shape. In examples, the board 204 may have subtle curves or deviations from a substantially rectangular shape.

[0021] In examples, the standing surface 205 may be between 400-800 mm in length. In an example the standing surface 205 may be 640 mm in length. In an example, the standing surface 205 may be between 100-350 mm in width. In an example, the standing surface may be 310 mm in width. In examples, the standing surface 205 may be sized to accommodate an adult or child’s stance, or any range between. In examples, the standing surface 205 may be fabricated from wood, aluminum, a carbon fiber composite, and / or any other suitable material.

[0022] In examples, the board 204 may include one or more foot pads 207. In examples, one or more foot pads 207 may be wedge shaped or any shape operable to allow the rider greater comfort or stability when standing on or turning the two-wheeled vehicle 100. In examples, the feeling of the one or more foot pads 207 underfoot may provide the user feedback about whether their feet are in the desired positions on the standing surface 205 without needing to look down. In examples the one or more foot pads 207 may be coupled to the standing surface 205 of board 204 using one or more fasteners or adhesives.

[0023] In examples, board 204 may include one or more surfaces or indented seats for coupling other components to. In examples, board 204 may comprise a clamshell-type container for additional components. In examples, board 204 may include pockets for other components to be seated and / or fastened into. The assembly of the board 204 with other elements will be described with respect to the motor and battery below.

[0024] In examples, the front wheel 202 and rear wheel 206 may comprise any type of wheels that may be coupled to the board 204. In examples, front wheel 202 and board 204 may include rims that seat inflatable tires with or without tubes. In examples, the front wheel 202 and the rear wheel 206 of the two-wheeled vehicle 100 may be coupled to the board 204 to align with a longitudinal axis 208 of the board 204. In examples, the front wheel 202 and rear wheel 206 may have the same or different diameters. In examples the wheel diameters may be 200-400mm. In an example, the wheel diameters may be 280mm.

[0025] In examples, the front wheel 202 may be coupled to the board 204 via a swivel assembly 602 (see broken line circle in the details of FIGs. 6 and 7). In examples, the swivel assembly 602 may include any combination of a housing 604, a steer shaft 606, a bidirectional biasing member 608, a first bearing 612, a second bearing 614, a clamp member 616, a damping member 618, a cover 620, and a fork 622.

[0026] The swivel assembly 602 is configured to pivot the front wheel 202 along a swivel assembly axis 626 located within a vehicle plane 624 aligned with the longitudinal axis 208.The swivel assembly 602 is operable to rotate the front wheel along the swivel assembly axis with respect to the vehicle plane 624.

[0027] A wheel plane 625 traverses the front wheel 202 orthogonal to the front wheel axis 209. The front w heel 202 includes a rim 629 that spins in parallel with and centered in an axial direction on the w heel plane 625. When the front wheel 202 is aligned with the longitudinal axis 208, the vehicle plane 624 aligns with the wheel plane 625. When the front wheel 202 pivots via the swivel assembly axis 626, the wheel plane 625 rotates out of alignment with the vehicle plane 624.

[0028] The swivel assembly 602 is designed to allow the front wheel 202 to align with the direction of travel determined by a rider’s lean on the board 204. In other w ords, when a rider initiates a turn of the two-wheeled vehicle 100 by leaning toe side or heel side, the longitudinal axis 208 of the board 204 is rotated. The swivel assembly 602 allows the front wheel 202 to pivot in the direction that the board 204 angles downw ard, thereby providing stability' for the rider to hold the rotated position of the board 204 in a turn without over rotating.

[0029] The example two-wheeled vehicle 100 provided does not include the handlebar that prior scooters use to control the pivot of front w heel 202. Without a handlebar, it may be challenging for a rider, using only balance, to prevent the front wheel 202 from over rotating or rotating too quickly along the axis of the front wheel 202. Similarly, it may be difficult for a rider to reverse the rotation direction and / or return the front wheel to a neutral turning position that is aligned with the longitudinal axis 208 when desired. If the rotation of the swivel assembly 602 does not feel smooth and controlled, the rider will not feel safe using the two-wheeled vehicle 100 at higher speeds.

[0030] In examples, the swivel assembly 602 may therefore include a bidirectional biasing member 608 operable to bias a rotational alignment of the front wheel 202 along the swivel assembly axis 626 to align with the vehicle plane 624 and the longitudinal axis 208.

[0031] Aligning the front wheel 202 w ith the vehicle plane 624 may cause the tw o-w heeled vehicle 100 to restore or maintain travel in a direction parallel to the longitudinal axis 208 of the board 204. The bidirectional biasing member 608 may provide bidirectional resistance when a force is applied to turn the front wheel 202 away from alignment with the longitudinal axis 208 of the board 204. In examples, the bidirectional biasing member 608 may provide resistance to a turning force that is proportionate to rotational displacement of the front wheel 202 out of the vehicle plane 624, slowing down a turn to the left or right. When there is no turning force applied to rotate the front wheel 202 away from the vehicle plane 624, thebidirectional biasing member 608 may exert a restore force operable to rotate the front wheel 202 back into alignment with the vehicle plane 624.

[0032] In examples, the bidirectional biasing member 608 may include a spring, for example the bidirectional torsional spring positioned concentric the steer shaft 606, as further described below. A torsion spring is a mechanical device that exerts rotational force (torque) in response to angular displacement. Torsion springs store energy when twisted and release it when allowed to return to a neutral position. A bidirectional torsion spring can provide restoring torque in both clockwise and counterclockwise directions, depending on the direction of applied rotation. In examples, the bidirectional biasing member 608 may be a dual-coil torsion spring. In examples, the bidirectional biasing member 608 may comprise a double helix coil. In examples, the bidirectional biasing member 608 may be equally balanced in a clockwise and counterclockwise direction. In examples, the bidirectional biasing member 608 may exert opposite spring forces upon rotation from the two helix or coil element, with a first element exerting a compressive force while the second element is exerting an expansion force and vice-versa in the opposite direction.

[0033] The bidirectional biasing member 608 may bidirectionally bias the front wheel 202 towards a position aligned with the longitudinal axis 208 so that the two-wheeled vehicle 100 moves in a direction aligned with the longitudinal axis 208 unless the rider leans to the left or right to overcome the force of the bidirectional biasing member 608. In other w ords, the bidirectional biasing member 608 may restore the two-wheeled vehicle 100 to travel in a straight direction in line with the longitudinal axis 208 unless the rider leans to the left or right when traveling and overcomes that bias.

[0034] The bidirectional biasing member 608 may further prevent the swivel assembly 602 from overturning and "jack knifing" the front wheel 202 of the two-wheeled vehicle 100. which could possibly cause a rider to crash.

[0035] In the example of FIG. 7, the bidirectional biasing member 608 is a torsion spring. The bidirectional biasing member 608 may have a “relaxed” position that is straight and not pre-loaded. In examples, the bidirectional biasing member 608 may have a design is fault- tolerant against a spring failure so that if the bidirectional biasing member 608 were to fail, it may allow the rider to continue straight. This may provide advantages over stretched and pre-loaded tension or compression or torsion springs, because if those spring types break, it may cause the wheel to abruptly turn, possibly causing a rider crash and injury. In the example, the bidirectional biasing member 608 is a machined torsion spring. In examples, the bidirectional biasing member 608 may be a double helix spring. In examples, bidirectionalbiasing member 608 may comprise further arrangements, for example one or more: torsion bars, torsion springs, flexure hinges, spiral springs, magnetic torsion springs, electromagnetic torsion actuators, magneto restrictive materials, bidirectional servo motors with spring couplings, voice coil actuators with rotary suspension, pneumatic rotary actuators with centering springs, shape memory alloy springs, or dielectric elastomer actuators.

[0036] In examples, the bidirectional biasing member 608 may help the two-wheeled vehicle 100 feel more stable, especially at higher speeds. The bidirectional biasing member 608 may help the two-wheeled vehicle 100 ride more like a snowboard, which glides straight unless the rider leans tow or heel side enough to catch an edge.

[0037] In examples, the bidirectional biasing member 608 may be selected based on rider weight to allow for the best steerability. For example, the bidirectional biasing member 608 for an 80 lb. child may require half the stiffness of the bidirectional biasing member 608 designed for an adult. In examples, the bidirectional biasing member 608 may be adjustable to accommodate riders with multiple weights and sizes.

[0038] FIGs. 6 and 7 provide a more detailed view of the stack of components designed and assembled to form the swivel assembly 602.

[0039] In examples, the swivel assembly 602 may include a housing 604. The housing 604 comprises a structure operable to rotatably couple the steer shaft 606 to the board 204 via the bidirectional biasing member 608. In examples, the housing 604 may be integrated into or coupled to a front wheel coupling member 628.

[0040] The example front wheel coupling member 628 has a gooseneck shape, with a head providing a surface to integrate into swivel assembly 602 and the opposing end providing a surface to couple to a front end 630 of the board 204.

[0041] The example swivel assembly 602 includes a steer shaft 606. A first end 640 of the steer shaft 606 may be coupled to or integrated to a fork 622. Fork 622 may include any wheel coupling mechanism operable to attach one side of a rotatable wheel hub to a steer tube. In examples, the fork 622 may include dropouts for coupling front wheel 202 to the swivel assembly 602 via, for example, an axle passing through a wheel hub.

[0042] In examples, an exterior of the steer shaft 606 may have a stepped-shape with two annular surfaces to seat bearings. For example, the steer shaft 606 may include a first annular surface 641 operable to seat a first bearing 612 on the first end 640 of the steer shaft 606. The steer shaft 606 may further include a second annular surface 643 with a smaller radius than the first annular surface 641. the second annular surface 643 operable to seat a second bearing 614 on a second end 645 of the steer shaft 606 opposing the first end 640. The aperture 638of the steer shaft 606 may also be stepped to provide surfaces for the first bearing 612 and second bearing 614 to seat against when the steer shaft 606 is assembled within the housing 604.

[0043] In examples, the first bearing 612 and the second bearing 614 may be positioned on the first annular surface 641 and the second annular surface 643 of the steer shaft 606 respectively. Next, the steer shaft 606 may be inserted into the aperture 638 of the housing 604 via a first surface 647. The first bearing 612 and second bearing 614 may rotatably couple the steer shaft 606 within the aperture 638 of the housing 604.

[0044] In examples, the bidirectional biasing member 608 may be seated into the housing 604. In examples, the housing 604 may include a second surface 646 on an opposite end of the housing 604 from the first surface 647, through which the aperture 638 also passes. The second surface 646 may further include a depression 648 having a hollow cylinder shape positioned to be concentric with the aperture 638. The depression 648 may be shaped to seat the bidirectional biasing member 608 therein.

[0045] In examples, the bidirectional biasing member 608 may include a second alignment feature 650 (see perspective view of bidirectional biasing member 608 in FIG. 7) and an annular inner surface 652 of the depression 648 may include a first alignment feature 651 (see cross section FIG. 6). The first alignment feature 651 may seat with the second alignment feature 650 to secure an orientation of the bidirectional biasing member 608 within the depression 648. In the example of the figures, the second alignment feature 650 is a series of square tab-like castellations and the first alignment feature 651 comprises like-shaped indentions. The second alignment feature 650 and the first alignment feature 651 may help maintain the rotational alignment of bidirectional biasing member 608 within the housing 604 so that the bidirectional biasing member 608 restores the alignment of the front wheel 202 to parallel the longitudinal axis 208 when the rider is not leaning on the board 204 to turn.

[0046] With the steer shaft 606 rotatably coupled to the housing 604 and the bidirectional biasing member 608 inserted into the depression 648, may next be possible to couple the steer shaft 606 to the second end 636 of the bidirectional biasing member 608.

[0047] In examples, a clamp member 616 may be used to couple the second end 645 of the steer shaft 606 to the first end 634 of the bidirectional biasing member 608. In examples, the clamp member 616 may comprise any structure operable to couple steer shaft 606 to the bidirectional biasing member 608. The example clamp member 616 depicted in FIGs. 6 and 7 is substantially disk-shaped, covering the second end 645 of the steer shaft 606 and extending radially to also contact the bidirectional biasing member 608.

[0048] As may be seen in FIG. 7, the steer shaft 606 may include a first alignment feature at the second end 645, for example castellations (see FIG. 7), that are configured to seat with a second alignment feature, for example indentations (not depicted) on a bottom side of the clamp member 616. The alignment features of the steer shaft 606 may center and / or align the clamp member 616 with respect to the steer shaft 606 so that apertures in the clamp member 616 align with boreholes for fasteners 654 (see FIG. 6) in the second end 645 of the steer shaft 606. In other examples further methods are possible to couple the clamp member 616 to the steer shaft 606, however.

[0049] In examples, the clamp member 616 may be further configured for coupling to a second end 636 of the bidirectional biasing member 608. In the example, a peripheral area of the clamp member 616 contacts the second end 636 of the bidirectional biasing member 608. In order to secure the second end 636 of bidirectional biasing member 608 with respect to the clamp member 616, one or more alignment features may be used. For example, the second end 636 of the bidirectional biasing member 608 may include a first alignment feature 653. In examples, the alignment feature 653 at the first end 634 of the bidirectional biasing member 608 may be similar to the alignment feature 651 at the second end 636 of the bidirectional biasing member 608.

[0050] The clamp member 616 may include a second alignment feature 655 configured to seat with the first alignment feature 653 of the bidirectional biasing member 608 to secure a rotational orientation of the bidirectional biasing member 608 with respect to the clamp member 616. In the example, it may be seen that the second alignment feature 655 of the clamp member 616 is a set of indentations shaped to fit snuggly around the first alignment feature 651 of the bidirectional biasing member 608.

[0051] The alignment features described herein may secure the clamp member 616 with respect to the steer shaft 606 and bidirectional biasing member 608 so that the steer shaft 606 and the housing 604 interact rotationally through the bidirectional biasing member 608.

[0052] In examples, the swivel assembly 602 may further include a damping member 618. The damping member 618 may be operable to dissipate a rotational motion of the swivel assembly. By damping the rotations of the swivel assembly 602, it may be possible to stiffen the steering of the two-wheeled vehicle 100 and provide a more stable ride at higher speeds.

[0053] In examples, the damping member 618 may be a fluid damper, such as a viscous fluid damper. For example, the clamp member 616 may include an annular indention 656 configured to receive a viscous damping grease. The swivel assembly 602 may further include a cover 620 configured for coupling to a surface of the housing 604 adjacent to theclamp member 616. As may be seen in FIG. 6, the cover 620 may include an annular protrusion 657 on the swivel assembly -facing side of the cover 620. The annular protrusion 657 may secure and / or compress the damping member 618 within the annular indention 656, shearing the fluid between rotating surfaces within the assembly and thereby removing rotational energy from swivel assembly 602.

[0054] In examples, the damping member 618 may be an eddy current damper comprised of permanent magnets which induce eddy currents thereby dampening motion. In examples the damping member 618 may include a speed-dependent dampening mechanism.

[0055] In examples, the two-wheeled vehicle 100 may include speed-dependent steering. For example, the swivel assembly 602 may include a motor or an electrically controllable brake operable to change the stiffness of the steering axis, thereby allowing the steering to move more easily at slow speeds and becoming stiffer at high speeds.

[0056] In examples, the damping member 618 may comprise an electrically controlled particle brake operable to dissipate a rotational motion of the swivel assembly 602 based on a signal representing a velocity of the vehicle. In examples, the two-wheeled vehicle 100 may include a velocity sensor and electronics operable to provide the signal to the electrically controlled particle brake. This may be advantageous because generally abrupt changes in direction at high speed may cause an accident.

[0057] In examples, the swivel assembly 602 may include electrically controlled steering. A steering motor may be operable to rotate the front wheel 202 based on a signal representing a rotation angle of the board 204 about a longitudinal axis 208 of the board 204. For example, the two-wheeled vehicle 100 may include a gyroscope or an IMU sensor operable to measure the angle of the board 204 and electronics operable to provide the signal to the steering motor. The electrically controlled steering may then use the signal representing the angle of the board caused by a rider’s lean to operate the direction of the front wheel 202 via a motor. In examples, the electrically controlled steering could also be speed dependent, with the steering angle rotating faster at slow speeds and slower at high speeds.

[0058] The rear wheel 206 may be coupled to the board 204 via a rear wheel coupling bracket 214. In examples, the rear wheel coupling bracket 214 may be configured to keep the rear wheel 206 in a position that doesn’t pivot with respect to the longitudinal axis 208 the board 204.

[0059] In examples, the rear wheel coupling bracket 214 may support a fender 658 via a support portion 661 extending from the hub of the rear wheel 206 to prevent water from splashing up towards the rider.

[0060] In examples the rear wheel coupling bracket 214 may include a rear handle 659. In examples, the rear handle 659 may be coupled to or extend from the support portion 661 of the rear wheel coupling bracket 214. When combined with a front handle 660, which may extend from the housing 604 or front wheel coupling member 628 on the front of the twowheeled vehicle 100, the rear handle 659 may allow the rider to lift and store the twowheeled vehicle 100.

[0061] In examples, the rear wheel 206 may include a motor internal to the wheel (not depicted). For example, the rear wheel 206 may include a variable speed direct drive or geared electric motor to generate forward velocity for the rider. The rear wheel 206 may further provide resistive braking to slow and stop the two- wheeled vehicle 100. The rear wheel 206 motor may be operable wirelessly via handheld motor controller 102.

[0062] The rear wheel coupling bracket 214 may further provide routing for wires between a motor internal to the rear wheel 206 and a battery or controller located on the board 204. For example, FIG. 7 depicts an exploded view of the board 204. As may be seen, board 204 may include a stack comprising the standing surface 205, a battery 664, an electronics 670, a gasket 666. a bottom deck 668, and a skid plate 672. The standing surface 205 and bottom deck 668 may be formed from CNC machined wood with compartments to seat electronic components. When coupled together, standing surface 205 and bottom deck 668 may form a clamshell-style housing that is 37-39 mm thick to store the battery 664 and electronics 670. The gasket 666 may provide a tight, sealed fit around the electrical components.

[0063] The example of the figures is not intended to be limiting. In examples, the battery 664 and electronics 670 may be mounted to the top or bottom or to the inside of standing surface 205 in one or more positions. The battery may comprise a lithium battery. The speed controller may include a processor, a wireless communication interface, and a memory configured with instructions operable to sequence energizing one or more motors, including a motor integrated into the rear wheel 206, using power from the battery when commanded wirelessly to via handheld motor controller 102.

[0064] In an example, the two-wheeled vehicle 100 may include motors in both the front wheel 202 and the rear w heel 206. which would provide the benefit of higher torque for acceleration and deceleration. A dual motor two-wheeled vehicle may be helpful on steep terrain, for example.

[0065] In examples, front wheel 202 may include a front hub 674 with a front wheel axis 209 and the rear wheel 206 may include a rear hub 676 with a rear axis. The front axis and rear axis may intersect in a plane 678, which may be parallel to the ground when the tw o-wheeledvehicle 100 is in an operational position. In examples, the plane 678 may be positioned at or above the longitudinal axis 208 of the board 204. In other words, the front hub 674 and the rear hub 676 may overlap with a height of or be positioned above the board 204 when the two-wheeled vehicle 100 is in an operational position. Placing the plane 678 including the front hub 674 and the rear hub 676 slightly above longitudinal axis 208 of the board 204 may provide greater ground clearance. In further examples, the longitudinal axis 208 may be positioned slightly below the plane 678 with the front hub 674 and the rear hub 676 to provide for increased stability.

[0066] In examples, front wheel 202 may be positioned so that it is outside the perimeter of the board 204. In examples, the front wheel 202 is coupled to the board 204 with a swivel assembly 602 having a steering axis angle 304 that is greater than 10 degrees, between 10 and 75 degrees, between 60 and 80 degrees, between 65 and 72 degrees. In an example, the steering axis angle 304 may be 68 degrees.

[0067] The layout and / or positioning of the board 204 with respect to the front wheel 202 and the rear wheel 206 may allow the two- wheeled vehicle 100 to feel intuitive to steer and / or provide a stable feeling for a rider. In examples, the two-wheeled vehicle 100 may feel much like a skateboard or a snowboard.

[0068] In examples, the two-wheeled vehicle 100 may be configured so that the board 204 is 65mm above the ground when in an operational riding position.

[0069] In FIG. 3, the geometry of the two-wheeled vehicle 100 is depicted, including a steering axis angle 304, a fork offset 306, and a trail 308. The steering axis angle 304 is the angle between the swivel assembly axis 626 and a horizontal surface. In examples, the twowheeled vehicle 100 may have a steering axis angle 304 between 66-70 degrees. In examples, the two-wheeled vehicle 100 may have a steering angle of 68 deg. The fork offset 306 is the offset of the central axis of the front hub 674 from the swivel assembly axis 626 of the swivel assembly 602. In examples, the two-wheeled vehicle 100 may have a fork offset 306 of zero or between 10mm and 40mm. In examples, the two- wheeled vehicle 100 may have a fork offset 306 of 23mm with a tire having a 280mm diameter. The trail 308 is the distance between the steering axis of the swivel assembly axis 626 and the section of the tire that contacts the ground surface, and is determined by the steering axis angle 304, fork offset 306, and wheel diameter. In examples, the trail 308 may be between 8mm and 58mm. In examples, the trail 308 may be 33mm.

[0070] In some aspects, the techniques described herein relate to a vehicle, wherein the bidirectional biasing member is a torsion spring.

[0071] In some aspects, the techniques described herein relate to a vehicle, wherein the swivel assembly further includes: a damping member operable to dissipate a rotational motion of the swivel assembly.

[0072] In some aspects, the techniques described herein relate to a vehicle, wherein the damping member is a viscous fluid damper.

[0073] In some aspects, the techniques described herein relate to a vehicle, wherein the damping member is an electrically controlled particle brake operable to dissipate a rotational motion of the swivel assembly based on a signal representing a velocity of the vehicle.

[0074] In some aspects, the techniques described herein relate to a vehicle, wherein the swivel assembly further includes: a coupling member coupled to the front end of the board and a first end of the bidirectional biasing member; and a steer shaft coupled to a second end of the bidirectional biasing member opposing the first end of the bidirectional biasing member.

[0075] In some aspects, the techniques described herein relate to a vehicle, further including: a motor configured to rotate the rear wheel.

[0076] In some aspects, the techniques descnbed herein relate to a vehicle, wherein the motor is configured to be commanded wirelessly.

[0077] In some aspects, the techniques described herein relate to a vehicle, further including: a motor configured to rotate the front wheel.

[0078] In some aspects, the techniques described herein relate to a vehicle, further including, wherein the motor is operable to rotate the swivel assembly based on a signal representing a rotation angle of the board around a longitudinal axis of the board.

[0079] In some aspects, the techniques described herein relate to a vehicle, wherein the front wheel includes a front axis and the rear wheel includes a rear axis, the front axis and the rear axis overlapping with or positioned above the board in a direction perpendicular to the standing surface when the vehicle is in an operational position.

[0080] In some aspects, the techniques described herein relate to a swivel assembly, further including: a fork coupled to the steer shaft; and a wheel coupled to the fork.

[0081] In some aspects, the techniques descnbed herein relate to a swivel assembly, wherein a first bearing and a second bearing couple the steer shaft to the aperture in the housing.

[0082] In some aspects, the techniques described herein relate to a swivel assembly, wherein the housing further includes a first surface though which the aperture passes, the first surface further including a depression with a hollow cylinder shape positioned to be concentric with the aperture, the depression operable to seat the bidirectional biasing member.

[0083] In some aspects, the techniques described herein relate to a swivel assembly, wherein the bidirectional biasing member includes a first alignment feature and a surface of the depression includes a second alignment feature that seats with the first alignment feature to secure an orientation of the bidirectional biasing member within the depression.

[0084] In some aspects, the techniques described herein relate to a swivel assembly, further including: a clamp member configured to couple a second end of the bidirectional biasing member to the steer shaft.

[0085] In some aspects, the techniques described herein relate to a swivel assembly, wherein the second end of the bidirectional biasing member includes a first alignment feature and the clamp member includes a second alignment feature at a peripheral area that seats with the first alignment feature to secure an orientation of the clamp member with respect to the bidirectional biasing member.

[0086] In some aspects, the techniques described herein relate to a swivel assembly, wherein the clamp member includes a first alignment feature at a central area and the second end of the bidirectional biasing member includes a second alignment feature that seats with the first alignment feature to secure an orientation of the clamp member with respect to the steer shaft.

[0087] In some aspects, the techniques described herein relate to a swivel assembly, wherein the clamp member includes an annular depression configured to receive a fluid damper.

[0088] In some aspects, the techniques described herein relate to a swivel assembly, wherein the swivel assembly further includes: a cover configured to be coupled to a surface of the housing adjacent to the clamp member.

[0089] A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the specification.

[0090] In addition, any logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. In addition, other steps may be provided, or steps may be eliminated, from the described flow s, and other components may be added to, or removed from, the described systems. Accordingly, other embodiments are within the scope of the following claims.

[0091] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising." "including," and "having." are inclusive and therefore specify the presence of stated features, integers, steps, operations.elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0092] When an element or layer is referred to as being "on," "engaged to." "connected to." or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to." or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0093] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0094] Terms of degree such as "generally," "substantially," "approximately," and "about" may be used herein when describing the relative positions, sizes, dimensions, or values of various elements, components, regions, layers and / or sections. These terms mean that such relative positions, sizes, dimensions, or values are within the defined range or comparison (e.g.. equal or close to equal) with sufficient precision as would be understood by one of ordinary skill in the art in the context of the various elements, components, regions, layers and / or sections being described.

[0095] While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims areintended to cover all such modifications and changes as fall within the scope of the implementations. It should be understood that they have been presented by way of example only, not limitation, and various changes in form and details may be made. Any portion of the apparatus and / or methods described herein may be combined in any combination, except mutually exclusive combinations. The implementations described herein can include various combinations and / or sub-combinations of the functions, components and / or features of the different implementations described.

Claims

WHAT IS CLAIMED IS:

1. A vehicle comprising: a board including a standing surface and being aligned with a longitudinal axis; a rear wheel coupled within the vehicle toward a rear end of the board; a front wheel coupled to a front end of the board via a swivel assembly; and the swivel assembly including a bidirectional biasing member configured to bias alignment of the front wheel along the longitudinal axis of the board.

2. The vehicle of claim 1, wherein the bidirectional biasing member is a torsion spring.

3. The vehicle of claim 1. wherein the swivel assembly further comprises: a damping member operable to dissipate a rotational motion of the swivel assembly.

4. The vehicle of claim 3, wherein the damping member is a viscous fluid damper.

5. The vehicle of claim 3. wherein the damping member is an electrically controlled particle brake operable to dissipate a rotational motion of the swivel assembly based on a signal representing a velocity7of the vehicle.

6. The vehicle of claim 1. wherein the swivel assembly further comprises: a coupling member coupled to the front end of the board and a first end of the bidirectional biasing member; and a steer shaft coupled to a second end of the bidirectional biasing member opposing the first end of the bidirectional biasing member.

7. The vehicle of claim 1, further comprising: a motor configured to rotate the rear wheel.

8. The vehicle of claim 7. wherein the motor is configured to be commanded wirelessly.

9. The vehicle of claim 1, further comprising: a motor configured to rotate the front wheel.

10. The vehicle of claim 9, further comprising, wherein the motor is operable to rotate the swivel assembly based on a signal representing a rotation angle of the board around a longitudinal axis of the board.

11. The vehicle of claim 1, wherein the front wheel includes a front axis and the rear wheel includes a rear axis, the front axis and the rear axis overlapping with or positioned above the board in a direction perpendicular to the standing surface when the vehicle is in an operational position.

12. A swivel assembly comprising: a housing; a steer shaft operable to rotate within an aperture of the housing; and a bidirectional biasing member including a first end and a second end, the first end coupled to the housing and the second end coupled to the steer shaft, the bidirectional biasing member operable to restore a rotational alignment of the steer shaft with respect to the housing.

13. The swivel assembly of claim 12, further comprising: a fork coupled to the steer shaft; and a wheel coupled to the fork.

14. The swivel assembly of claim 12, wherein a first bearing and a second bearing couple the steer shaft to the aperture in the housing.

15. The swivel assembly of claim 14, wherein the housing further includes a first surface though which the aperture passes, the first surface further including a depression with a hollow cylinder shape positioned to be concentric with the aperture, the depression operable to seat the bidirectional biasing member.

16. The swivel assembly of claim 1 , wherein the bidirectional biasing member includes a first alignment feature and a surface of the depression includes a second alignment feature that seats with the first alignment feature to secure an orientation of the bidirectional biasing member within the depression.

17. The swivel assembly of claim 12, further comprising: a clamp member configured to couple a second end of the bidirectional biasing member to the steer shaft.

18. The swivel assembly of claim 17, wherein the second end of the bidirectional biasing member includes a first alignment feature and the clamp member includes a second alignment feature at a peripheral area that seats with the first alignment feature to secure an orientation of the clamp member with respect to the bidirectional biasing member.

19. The swivel assembly of claim 17, wherein the clamp member includes a first alignment feature at a central area and the second end of the bidirectional biasing member includes a second alignment feature that seats with the first alignment feature to secure an orientation of the clamp member with respect to the steer shaft.

20. The swivel assembly of claim 17, wherein the clamp member includes an annular depression configured to receive a fluid damper.

21. The swivel assembly of claim 17, wherein the swivel assembly further comprises: a cover configured to be coupled to a surface of the housing adjacent to the clamp member.

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