This application claims the benefit of British Patent Application No. 1514366.2, filed Aug. 13, 2015, the contents of which are incorporated herein by reference in their entirety.
The present invention relates generally to vehicles, and, in particular, to a wheel for a human-powered vehicle therefor.
When people are learning to ride a bike, they must acquire the reflex skills to steer the bicycle to maintain its orientation with respect to the ground so that the centre of gravity of the bicycle and the rider together is in equilibrium, either central if going in a straight line, or displaced towards the centre of any cornering arc. Gyroscopic precession is a phenomenon that has long been used to stabilise the balance of objects and it has long been understood that all bicycle wheels have an inherent gyroscopic effect themselves that helps to balance a bike which is greater when they are large and heavy.
Some proposed devices supplement the gyroscopic effect of the bicycle wheels for the purposes of balance training and assisted bicycle riding with an additional gyroscope contained around the bicycle or within the wheel that is purposefully heavy and rotates at greater speed than the bicycle wheel. Furthermore, they describe that if this additional gyroscope rotates coaxially and in the same rotational direction as the front wheel of the bicycle then on becoming imbalanced, the precession effect of the gyroscope also induces the correct direction of steering to help restore balance equilibrium. The gyroscopic effect can be reduced by reducing the speed of rotation as the learner adopts the balancing reflex until such time that it may no longer be required.
The gyroscopic element of these devices, such as a disc or spoked flywheel with mass concentrated towards its outer region, must rotate quickly to provide sufficient gyroscopic effect. For the wheel to be safe in use, this disc or flywheel is contained within the bicycle wheel and fits within the space available between existing bicycle front forks and the front brakes. The outer covers of the wheel have been made in two similar circular parts which are affixed together to enclose the gyroscopic disc and to support the tyre by each cover supporting one side of the tyre side wall and edge. The two circular parts define an axis of the bicycle wheel and the gyroscopic disc or flywheel between the two circular halves, which may not be well aligned. In addition, it also subjects the mechanical fixings of the covers to the pressure contained within the tyre if pneumatically inflated. Furthermore, the gyroscope is contained within the wheel such that it requires skill to remove, and if not removed, the wheel remains heavy and is less preferable for bicycle riding if the gyroscopic effect is no longer required for training purposes. Still further, the split rim provided by the two circular parts is held together around the outer diameter by screws. This leads to stress concentrations around the fasteners.
The motive means to accelerate and maintain a fast rotating gyroscope are preferably small in size and without undue frictional and efficiency losses that act to limit the maximum terminal speed of the gyroscope and therefore its beneficial effect. Some systems described in the above-identified references transfer rotation from an electrical motor contained within the training wheel to a flat surface on the gyroscopic disc by the use of a smooth wheel attached to the motor shaft on which is retained in a channel a separable rubber or elastomer toroid with a smooth surface. The motor wheel and toroid are pushed against the gyroscopic disc by means of mechanical springs and the motion is constrained by a member which deflects in an axis perpendicular and tangential to the axis of rotation of the gyroscopic disc. A problem with this arrangement is that the toroid is subject to its own inertial forces of rotation which limit its speed and the geometry of contact when acted upon by the mechanical spring leads to rapid wear through compression and friction and consequential loss of operation.
Another existing system requires electrical input to accelerate and then maintain the rotational speed of the gyroscopic disc that is then lost when the device is no longer used.
The heavy mass of a gyroscopic disc or flywheel is an inconvenience to a bicycle user that no longer requires the gyroscopic effect.
According to an aspect, there is provided a wheel for a human-powered vehicle, comprising a wheel hub rotatably mountable on a central axle defining a wheel rotation axis, a first cover secured to the wheel hub and comprising a circumferential rim structured to fully support a tyre thereon, and a second cover secured to one of the wheel hub and the first cover adjacent the wheel hub, and mating with the first cover distal from the wheel hub.
The first cover can comprise the circumferential rim coupled to a separate disc portion.
The second cover can be releasably secured to the one of the wheel hub and the first cover. The second cover can comprise a first circumferential rib that snugly abuts the circumferential rim when the second cover is secured to the one of the wheel hub and the first cover. The second cover can further comprise a second circumferential rib concentric with and adjacent to the first circumferential rib defining a circumferential groove that snugly receives the circumferential rim.
The first cover and the second cover can define an enclosure therebetween.
The wheel can further comprise a flywheel structure positioned in the enclosure, comprising a flywheel extending from a collar rotatably coupled to the wheel hub enabling rotation of the flywheel generally about the wheel rotation axis. The flywheel can be releasably secured to the collar. Alternatively, the flywheel structure is releasably coupled to the wheel hub.
A seal between the first cover and the second cover can be water-resistant.
The wheel can further comprise a flywheel drive positioned to drive the flywheel, and a control circuit coupled to the flywheel drive to control operation thereof.
The wheel can further comprise a separation detection mechanism that detects the separation of the second cover from the first cover, the separation detection mechanism being coupled to the control circuit to cause the control circuit to one of terminate operation of the flywheel drive and generate resistance to continued rotation of the flywheel when the second cover is separated from the first cover.
The control circuit can comprise a resistor that generates resistance to continued rotation of the flywheel when the second cover is separated from the first cover.
The first cover can comprise a pair of electrical contacts coupled to the control circuit, and the second cover can comprise an electrical bridging contact that bridges the pair of electrical contacts on the first cover when the second cover is secured against the first cover, the control circuit causing one of the termination of the operation of the flywheel drive and the generation of resistance to continued rotation of the flywheel when the electrical contacts are unbridged.
The separation detection mechanism can comprise an optical sensor positioned in the enclosure and coupled to the control circuit, the optical sensor, in response to detecting the presence of a threshold level of light, causing the control circuit to one of terminate the operation of the flywheel drive and generate resistance to continued rotation of the flywheel.
The separation detection mechanism can comprise an optical sensor positioned in the enclosure and coupled to the control circuit, wherein the flywheel has an aperture that periodically aligns with the optical sensor when the flywheel is rotating, the optical sensor, in response to detecting a pattern of light, causing the control circuit to one of terminate the operation of the flywheel drive and generate resistance to continued rotation of the flywheel.
The wheel can further comprise a manual power button for controlling the control circuit.
The wheel can further comprise a flywheel drive operable to apply a torque to a drive wheel positioned against the flywheel to drive the flywheel, the drive wheel having a drive rotation axis that is generally perpendicular to the wheel rotation axis, the drive wheel having a bevelled edge, and a bevelled surface on the flywheel generally extending along a line from an intersection point between the drive rotation axis and the wheel rotation axis.
At least one of the bevelled edge of the drive wheel and the bevelled surface of the flywheel can be comprised of one of a rubber, a polymer, and an elastomer.
The wheel can further comprise a suspension chassis to which the flywheel drive is secured, the suspension chassis biasing the flywheel drive towards the flywheel.
The suspension chassis can be pivotable about a pivot that is generally perpendicular to the wheel rotation axis.
The suspension chassis can be biased by a spring.
Pivoting of the suspension chassis towards the flywheel can be limited by a stop.
According to another aspect, there is provided a wheel for a human-powered vehicle, comprising a flywheel having a flywheel rotation axis, a flywheel drive applying a torque to a drive wheel for driving the flywheel, the drive wheel having a drive rotation axis that is generally perpendicular to the wheel rotation axis, the drive wheel having a bevelled edge, and a bevelled surface on the flywheel generally extending along a line from an intersection point between the drive rotation axis and the wheel rotation axis.
At least one of the bevelled edge of the drive wheel and the bevelled surface of the flywheel can be comprised of one of a rubber, a polymer, and an elastomer.
The wheel can further comprise a position adjustment mechanism to which the flywheel drive is secured, the position adjustment mechanism positioning the flywheel drive in contact with the flywheel.
The position adjustment mechanism can comprise a pivot that is generally perpendicular to the wheel rotation axis.
The position adjustment mechanism can comprise a spring.
Pivoting of the flywheel drive towards the flywheel can be limited by a stop.
According to a further aspect, there is provided a wheel for a human-powered vehicle, comprising a flywheel structure, comprising a collar rotatably mountable on a wheel hub, and a flywheel releasably secured to the collar.
The flywheel can be releasably secured to the collar via at least one fastener.
The flywheel can be releasably secured to the collar via a clip.
According to yet another aspect, there is provided a wheel for a human-powered vehicle, comprising a wheel structure, a flywheel positioned within the wheel structure, a flywheel drive positioned to drive the flywheel, a control circuit coupled to the flywheel drive to control operation thereof, a cover removably secured to the wheel structure and providing access to the flywheel, and a separation detection mechanism that detects the removal of the cover, the separation detection mechanism being coupled to the control circuit to cause the control circuit to one of terminate operation of the flywheel drive and generate resistance to continued rotation of the flywheel when the cover is removed from the wheel structure.
The control circuit can comprise a resistor that generates resistance to continued rotation of the flywheel when the cover is removed from the wheel structure.
The wheel structure can comprise a pair of electrical contacts coupled to the control circuit, and the cover can comprise an electrical bridging contact that bridges the pair of electrical contacts on the wheel structure when the cover is secured against the wheel structure, the control circuit causing one of the termination of the operation of the flywheel drive and the generation of resistance to continued rotation of the flywheel when the electrical contacts are unbridged.
The separation detection mechanism can comprise an optical sensor positioned in an enclosure defined by the wheel structure and the cover and coupled to the control circuit, the optical sensor, in response to detecting the presence of a threshold level of light, causing the control circuit to one of terminate the operation of the flywheel drive and generate resistance to continued rotation of the flywheel.
The separation detection mechanism can comprise an optical sensor positioned in an enclosure defined by the wheel structure and the cover and coupled to the control circuit, wherein the flywheel has an aperture that periodically aligns with the optical sensor when the flywheel is rotating, the optical sensor, in response to detecting a pattern of light, causing the control circuit to one of terminate the operation of the flywheel drive and generate resistance to continued rotation of the flywheel.
The wheel can further comprise a manual power button for controlling the control circuit.
Embodiments will now be described, by way of example only, with reference to the attached Figures, wherein:
The first disc cover 1 is affixed to the wheel hub 6 in such a manner that they only rotate coaxially about the central fixed axle 5 and to such an extent that the first disc cover 1 is coupled to the wheel hub 6 for part of its length from one end to approximately the middle of the length of the wheel hub 6. The first disc cover 1 has a circumferential rim lc monolithically formed therein that is structured to fully support a tyre thereon. In particular, the circumferential rim 1c has a generally flat lateral cross section with a pair of circular rim flanges 1d extending generally radially therefrom. The rim flanges 1d retain the beads of a tyre 4 between them.
Referring now to
The sleeve 3b of the flywheel 3c is fitted on a substantially conical or cylindrical surface 3a of the collar 8 such that the collar 8 may or may not remain in place when the flywheel 3c is removed. A threaded bolt 10 and a clip 14 are used to retain the flywheel structure 3 in place. In other embodiments, one or more bolts or clips, an adhesive, or any other suitable means to secure the flywheel 3c to the collar 8 can be used. It can be preferable that the means for securing the flywheel 3c to the collar 8 are releasable.
The second disc cover 2 is releasably secured in place on the wheel hub 6 similarly by means that may include a threaded bolt 12 or a clip 13, or both, or other such familiar means of retention. In some cases, such as where the first disc cover 1 extends across a large portion of the wheel hub 6, it can be desirable to releasably secure the second disc cover 2 to the first disc cover 1 adjacent the wheel hub 6. When the second disc cover 2 is secured in place, the circumferential rim 1c of the first disc cover 1 is snugly received between the first circumferential rib 2a and the second circumferential rib 2b of the second disc cover 2 about its circumference, providing a rigid wheel structure that distributes stress about its circumference.
If a straight-edged drive wheel was employed with the flywheel 3c, with the centre of the wheel running at the same speed of the flywheel 3c then the top half of the drive wheel would be moving more slowly than the flywheel 3c whilst the bottom half of the drive wheel would be moving more quickly. This difference in speed would lead to slip resulting in wear and friction between the drive wheel and the flywheel 3c. In order to reduce this slip, the drive wheel 16 has a bevelled edge 17 and the flywheel 3c has a corresponding bevelled surface 3d, which allow the drive wheel 16 to have approximately the same speed as the flywheel 3c across the whole contact region between the two surfaces.
The drive wheel 16 has an elastomeric, polymeric or rubber outer layer 16a which is terminated by an outer frustoconical or bevelled drive wheel edge 17 that corresponds to a corresponding frustoconical or bevelled flywheel surface 3d on the flywheel 3c such that a contact region is established therebetween. The width of the drive wheel edge 17 is in contact with the bevelled surface 3d of the flywheel 3c, and provides sufficient friction and continuous meshing together with the bevelled flywheel surface 3d with low wear. The outer layer 16a is attached to the drive wheel 16 by adhesive or an enveloping geometry, but preferably by inserting the drive wheel 16 in an over-moulding process that forms an inseparable engagement and encapsulation of the drive wheel 16 by the outer layer 16a, as shown. The bevelled drive wheel edge 17 and the bevelled flywheel surface 3d are arranged such that the contact region therebetween extends along a line extrapolated from the intersection of the rotation axis of both the collar 8 of the flywheel structure 3 and the drive wheel 16 in a manner familiar to the design of bevel gears.
When spinning at its top speed, the flywheel 3c has a lot of kinetic energy and, on its own, would take several minutes to slow down as the only losses are due to friction and air resistance. This is inconvenient for the user as it makes the wheel difficult to handle (i.e., it makes it difficult to control the steering the bicycle to the right or left). To address this, the gyroscopic bicycle wheel 100 employs an electronic brake to slow the flywheel 3c. The electronic brake can be activated via a manual power button on an exterior surface thereof. In addition, the electronic brake is activated when it is determined by a separation detection mechanism that the second disc cover 2 is absent. This is done both optically and electrically.
Upon detecting a pattern of light and darkness via the optical sensor 22, the flywheel drive 15 can apply braking to the flywheel 3c to stop its rotation as it might be hazardous to the gyroscopic bicycle wheel 100 or to other neighbouring objects, animals, and/or people. In another embodiment, an optical sensor positioned in the enclosure can detect a threshold level of light indicative of the absence of the second disc cover 2 and control operation of the flywheel drive accordingly via a control circuit to which it is coupled.
Absence of the second disc cover 2 can be detected in other ways, such as, for example, the use of a magnetic element in the second disc cover 2 and a corresponding Hall sensor in the first disc sensor 1. In another example, the first disc cover 1 can include a mechanical switch that is actuated by a physical element of the second disc cover 2 when positioned adjacent the first disc cover 1.
The first disc cover 1 of the gyroscopic bicycle wheel 100 can support the tyre 4 fully on its circumferential rim 1c, enabling some control over the transmission the forces applied by the weight of the bicycle and user via the central fixed axis 5 of the gyroscopic bicycle wheel 100 by means of the rotating wheel hub 6 to which the first disc cover 1 is affixed through to the circumferential rim 1c around which the tyre 4 is positioned. This spreads the stress from the tyre pressure around the whole circumference of the gyroscopic bicycle wheel 100, leading to a stronger wheel. Thus, the first disc cover 1 is effectively the wheel structure, and the first disc cover 1 and the second disc cover 2 enclose the flywheel structure 3, control electronics, and the flywheel drive 15, sealing them from the environment and generally preventing users from accessing the spinning flywheel 3c. Furthermore, the construction allows the flywheel 3c to be more readily removed upon prior removal of a single cover, specifically the second disc cover 2 in the example shown. This can be done without need to remove any bearings. Further, there can be a static seal between the first disc cover 1 and the second disc cover 2, and only the smallest bearings need to be sealed.
Referring again to
The gyroscopic bicycle wheel 100 is able to provide increased levels of gyroscopic precession through increased rotation speed of the flywheel 3c that need not be heavier or larger. The gyroscopic effect can be maintained for longer periods and for an extended life which improve its effectiveness in training and in providing balance assistance for longer journey and requires shorter energy storage recharge times all other factors being common.
The structure of the circumferential rim can be varied to support different types of tyres. In one embodiment, a valve of the inner tube protrudes through a valve opening in the circumferential rim 1c of the first disc cover 1 and is angled against the inside of the circumferential rim 1c to reduce interference with the flywheel 3c. In another embodiment, an inner tube and corresponding tyre having a valve disposed along its lateral side are employed. In yet another embodiment, tubeless tyres are employed with the gyroscopic bicycle wheel. Where a tubeless tyre is employed, rim flanges can be omitted from the circumferential rim and the tyre can be adhered onto the circumferential rim.
The second disc cover need not be round on its exterior and may take on other shapes, but preferably encloses the flywheel structure.
While the second disc cover extends to the circumference of the first disc cover and the circumferential rim in the above-described embodiments, in other embodiments, it can extend partially to the circumference of the wheel, with one or more features at or close to the periphery of the second disc cover, such as a groove, matching one or more corresponding features on the first disc cover. This configuration can provide a reduced enclosure for movement of a flywheel therein. The second disc cover can be of other shapes, such as square, hexagonal, etc.
The drive rotation axis can, in other embodiments, be generally non-perpendicular to the wheel rotation axis. For example, the bevelling of the drive wheel can be modified to enable the drive rotation axis to be varied without changing the bevelled surface on the flywheel as compared to the bevelled surface shown in the figures.
While, in the above-described embodiments, the flywheel drive is a motor, the flywheel drive can be any suitable mechanism for driving the flywheel. In one alternative embodiment, the flywheel drive is operated by a spring-retracted cord, enabling the flywheel to be manually spun. In another alternative embodiment, the flywheel drive can be spring-driven.
In the above-described embodiments, the manual power button and the separation detection mechanism(s) are coupled to the control circuit to both terminate operation of the flywheel drive and brake the flywheel. In other embodiments, the manual power button and the separation detection mechanism can only perform one of these functions. Further, none, one, or more separation detection mechanisms can be employed to detect the separation of the second disc cover from the first disc cover.
In alternative embodiments, the flywheel structure is retained in place on the wheel hub via a clip or other suitable securing means, and is removed in its entirety from the wheel via removal of the second cover.
While the gyroscopic wheel was described with reference to bicycles, it will be appreciated that the same principles can be applied to other types of wheels for human-powered vehicles, such as tricycles, scooters, or any other suitable type of human-powered vehicle.
In some embodiments, fasteners such as screws can be employed to secure the second disc cover to the first disc cover distal from the wheel hub.
Persons skilled in the art will appreciate that there are yet more alternative implementations and modifications possible, and that the above examples are only illustrations of one or more implementations. The scope, therefore, is only to be limited by the claims appended hereto.
Number | Date | Country | Kind |
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1514366.2 | Aug 2015 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2016/069345 | 8/15/2016 | WO | 00 |