THREE-WHEELED SCOOTER

Abstract

THREE-WHEELED SCOOTER A scooter includes a platform (1) for the rider. A handlebar (3) is mounted to pivot for steering the scooter. A front wheel (2) is also mounted to pivot and is connected to the handlebar (3) by a steering stem (4) to form a steerable front wheel (2). Two rear wheels (5) are connected to the platform (1) by a first pivot joint allowing the two rear wheels (5) to pivot so that one of the two rear wheels (5) moves closer to the front wheel (2) while the other of the two rear wheels (5) moves away from the front wheel (2). The two rear wheels (5) are connected to the platform (1) by a second pivot joint allowing the two rear wheels (5) to pivot so that one of the two rear wheels (5) moves closer to the platform (1) while the other of the two rear wheels (5) moves away from the platform (1).

Description

Title of the invention: THREE-WHEEL SCOOTER Technical field

[0001] The invention relates to a three-wheeled scooter and a method of using such a scooter. Prior art

[0002] To get around, it is advantageous to replace the car with a more maneuverable and less bulky means of transport. The use of a motorized scooter has emerged as a particularly practical means of transport, especially in urban areas.

[0003] Multiple configurations of scooters are known, each having a front wheel and a rear wheel that are aligned along the longitudinal axis of the scooter. The scooter has a platform that is designed to accommodate the user's two feet. When moving, both feet are on the platform and, depending on the speed of the vehicle, it is necessary to pivot the handlebars or lean in order to turn the vehicle.

[0004] It appears that during use a certain fringe of users is not comfortable with such a mode of operation. This problem can be increased when the quality of the road surface is degraded and the speed of movement is low, which makes balance precarious because the vehicle only has two wheels.

[0005] In order to make the platform more stable, it has been proposed to increase the number of wheels on the scooter, in particular by transforming it into a "skateboard" or roller board by adding handlebars. Document US 3,751,062 discloses a configuration with two front wheels and two rear wheels. The right and left wheels are arranged on either side of the median longitudinal axis to increase stability. However, the main consequence of this modification of the running gear is to degrade its ability to turn, particularly at low speed. To turn, it is necessary to lean as with a conventional skateboard. This solution is not satisfactory and makes use difficult or even impossible for people whose balance could be improved. A substantially equivalent teaching is presented in document US 2,330,147.

[0006] Another scooter configuration is disclosed in US2003 / 0188906 or US1664858 which shows a vehicle with a front steering wheel and two rear wheels. The front wheel is connected to a handlebar and the assembly is pivotally mounted like the front axle of a bicycle. The platform is arranged parallel to the ground surface by means of the two rear wheels. This configuration seems manageable at low speed, but appears more difficult to maneuver as speed increases.

[0007] The Yamaha company has disclosed under the name "Tritown" a three-wheeled scooter with two front wheels and a rear wheel which provides propulsion. The two front wheels are mounted pivoting to the right or left and tilting relative to the vertical direction. The specific configuration of the front axle makes this technical solution appear expensive to produce and repair.

[0008] There are still a multitude of three-wheeled electric scooters where the two rear wheels are each mounted on a pivoting arm in the longitudinal extension of the platform. The two arms are connected by a shaft arranged to pivot the arms relative to the platform so that the platform can tilt to the right or left. This configuration does not allow for a large turning radius. Subject of the invention

[0009] An object of the invention is to provide a three-wheeled scooter which has good turning capabilities at low speeds and at higher speeds while being simple to manufacture so that it can be manufactured and / or repaired economically.

[0010] We tend to achieve this result by means of a scooter comprising: - a platform intended to receive a user, - a handlebar mechanically connected to the platform, the handlebar being pivotally mounted to steer the scooter - a front wheel mounted to pivot and connected to the handlebars by a steering rod to form a steered front wheel, the front wheel being single and connected to the platform by means of the steering rod; - two rear wheels connected to the platform.

[0011] The scooter is remarkable in that the two rear wheels are connected to the platform by a first pivoting connection allowing the two rear wheels to pivot relative to a first axis so that one of the two rear wheels moves closer to the front wheel while the other of the two rear wheels moves away from the front wheel and in that the two rear wheels are connected to the platform by a second pivoting connection allowing the two rear wheels to pivot relative to a second axis so that one of the two rear wheels moves closer to the platform while the other of the two rear wheels moves away from the platform.

[0012] Advantageously, the two rear wheels are fixed to two ends of a rotation shaft and wherein the rotation shaft is fixed to the platform by the first pivoting connection and by the second pivoting connection.

[0013] In a particular configuration, the front wheel is mounted in translation according to a longitudinal axis of the steering rod.

[0014] In an advantageous development, at least one of the first pivoting connection and the second pivoting connection is formed by at least one elastic deformable pad, the at least one pad deforming to pivot the two rear wheels.

[0015] Preferably, the scooter comprises a speed sensor configured to measure a speed of movement of the scooter along an axis of the platform and a blocker configured to reduce an amplitude or block a pivoting of the two rear wheels around the second axis when the sensor detects a speed lower than a threshold speed.

[0016] According to one embodiment, the second pivoting connection comprises a body and the axle is mounted to pivot about the second axis of rotation relative to the body, wherein the body and the axle respectively define a first hole and a second hole, the first hole being aligned with the second hole when the platform is in a rest position. A rod is mounted to move between a first position where the rod is able to be inserted into the first turn and the second hole aligned and a second position where the rod is at least one distance from the first hole and the second hole. The rod is connected to the speed sensor to be in the first position when the sensor detects a speed lower than a threshold speed.

[0017] The invention also relates to a method of using a scooter which is easy to steer in a greater speed range than the scooters of the prior art while remaining simple to manufacture.

[0018] This result is achieved by means of a method of using a scooter comprising the following steps: - provide a scooter according to any of the preceding configurations; - apply a greater vertical force to the right side of the platform than to the left side to pivot the platform and bring the platform closer to the right wheel and to move the left wheel away from the front wheel.

[0019] In a preferred development, the method comprises decelerating until a threshold speed is reached, the platform locking in a position where the two rear wheels are substantially equidistant from the platform in a vertical direction. Brief description of the drawings

[0020] Other advantages and characteristics will emerge more clearly from the following description of particular embodiments and implementations of the invention given as non-limiting examples and represented in the appended drawings, in which:

[0021] [Fig. 1]: schematically illustrates a first embodiment of a scooter in side view;

[0022] [Fig.2]: schematically illustrates a second embodiment of a scooter in side view;

[0023] [Fig.3]: schematically illustrates a bottom view of the first embodiment of a scooter;

[0024] [Fig.4]: schematically illustrates a rear view of the first embodiment of a scooter;

[0025] [Fig.5]: schematically illustrates an embodiment of a scooter with a view to side. Description of the embodiments

[0026] Figures 1 to 5 illustrate different embodiments of a scooter. The scooter has a platform 1 intended to receive a user, and preferably a user in a standing position. The scooter also has a front wheel 2 which is mechanically connected to the platform 1. The front wheel 2 is pivotally mounted so as to steer the scooter. The front wheel is preferably single.

[0027] A handlebar 3 is connected to the platform. The handlebar 3 is pivotally mounted so as to form a means for steering the scooter, i.e. turning it to the right or left. The handlebar 3 is connected to the front wheel 2 by a steering tube 4 which is pivotally mounted relative to the platform 1. The steering tube 4 defines a caster angle a whose value is adapted to the needs.

[0028] The front wheel 2 and the two rear wheels 5 are connected to the platform 1 in the longitudinal direction of the platform 1.

[0029] The scooter has two rear wheels 5 which are mechanically connected to the platform 1 by a pivoting member 6. The pivoting member 6 can be a “truck” of a skateboard. Depending on the configurations, the “truck” defines one pivoting connection or two pivoting connections. It is also possible for the “truck” to define a ball joint whose three-dimensional mobility is limited in order to favor two pivots around two different axes and preferably around two perpendicular axes.

[0030] The pivoting member 6 defines at least one pivot axis configured to pivot the two rear wheels 5 relative to the platform 1. The pivot axis makes it possible to bring one of the rear wheels 5 closer together and to move the other away. The pivot axis extends mainly in the longitudinal direction of the platform 1.

[0031] In another embodiment, the two rear wheels 5 are connected to the platform 1 by means of the pivoting member 6 which ensures the rotation of the two rear wheels 5 according to one or two different pivot axes. Preferably, the pivoting member 6 defines two pivoting connections which allow the two pivotings distinct.

[0032] The pivoting member may be a skateboard truck which has at least one deformable pad. The deformable pad is arranged between a rod of the base fixed to the platform and the axle which supports the rear wheels 5. The axle may have a pin which is inserted into a hole in the base. The position and the dimension of the hole limit the three-dimensional inclinations of the axle relative to the base. Such a configuration is known from the prior art.

[0033] The diameter of the front wheel 2 is greater than the diameter of each rear wheel 5. Preferably, the ratio between the diameter of the front wheel and the rear wheel is greater than 1.25, preferably greater than 1.5 and more preferably greater than 1.75. The use of a scooter whose front wheel 2 is larger than the rear wheels 5 makes it possible to improve the crossing characteristics in comparison with a scooter whose wheel diameters are identical or a scooter whose front wheel diameter 2 is smaller than the rear wheel diameter 5.

[0034] The two rear wheels 5 are connected to the platform 1 by a first pivoting connection allowing the pivoting of the assembly formed by the two rear wheels 5 relative to a first axis so that one of the two rear wheels 5 moves closer to the platform 1 while the other of the two rear wheels 5 moves away from the platform 1. When the two rear wheels 5 are against the ground, the first pivoting axis ensures the pivoting of the platform 1 relative to the plane defined by the ground, that is to say a “rolling” type movement.

[0035] Preferably, in addition to the first pivoting, the two rear wheels 5 are connected to the platform 1 by a second pivoting connection allowing the two rear wheels 5 to pivot relative to a second pivot axis so that one of the two rear wheels 5 moves closer to the front wheel 2 while the other of the two rear wheels 5 moves away from the front wheel 2. The type of pivoting of the rear wheels 5 is substantially identical to the type of pivoting of the front wheel 2. The rear wheels 5 pivot to facilitate rotation at low speed. With only the first pivoting, the front wheel 2 and the rear wheel 5 can allow the scooter to turn while keeping the platform in a position substantially parallel to the plane of the road, i.e. a “yaw” type movement.It is advantageous for the pivot axis of the front wheel 2 and the pivot axis of the rear wheel 5 to belong to the same plane and more preferably to a plane which contains the longitudinal direction of the platform 1.

[0036] Depending on the configurations, the two pivots can be independent or the pivot member 6 makes the two pivots linked and occur simultaneously.

[0037] In order to efficiently and economically achieve the pivoting of the assembly formed by the two rear wheels 5 relative to the platform 1, it is particularly advantageous to install the two rear wheels 5 on a skateboard truck. The truck defines an axle which receives at each of its transverse ends one of the rear wheels 5. It is preferable that each of the rear wheels 5 is mounted freely. The axle forms a rotation shaft for the two rear wheels 5. The rotation shaft is pivotally mounted by means of the pivot member 6.

[0038] The axle is pivotally mounted relative to the platform 1 and more preferably relative to the longitudinal axis of the platform 1 by means of the first pivoting connection. The first pivoting connection makes it possible to rotate the rear wheels 5 so that one of the rear wheels 5 moves closer to the front wheel 2 while the other rear wheel 5 moves away from the front wheel 2. The axle rotates about a pivot axis which intersects the plane defined by the surface for receiving the user's feet on the platform 1.

[0039] The axle is pivotally mounted relative to the platform 1 and more preferably relative to the lower face of the platform 1 by means of the second pivoting connection. The second pivoting connection makes it possible to pivot the axle in order to modulate the angle of inclination between the plane defined by the foot-receiving surface and the direction which connects the axes of rotation of the two rear wheels 5.

[0040] This embodiment is particularly advantageous when the platform 1 has a transverse dimension which is significant. For example, the transverse dimension of the platform is greater than 1.5 times the spacing of the two rear wheels 5, preferably greater than 2 times the spacing of the two rear wheels 5. The presence of a platform 1 whose width is significant facilitates the installation of the two feet of the user side by side in the transverse direction. When moving, the frontal plane of the user is perpendicular to the longitudinal axis of the platform, which facilitates the inclination of the user to pivot the platform 1 relative to the ground and turn the scooter to the right or to the left.

[0041] It has been observed that the use of the first pivoting connection makes it possible to have a scooter which has a better ability to turn right and left at low speed in comparison with a scooter which only has the second pivoting connection. On the other hand, when the speed of movement is high, it is advantageous to tilt the platform 1 to induce a turn and have a better position opposing the centrifugal force.

[0042] The combination of the first pivoting connection and the second pivoting connection allows, when the platform 1 is tilted, to rotate the two rear wheels 5 around the first pivoting connection. By leaning to the left or right, the user causes the two rear wheels 5 to move relative to the front wheel 2. When the user turns the handlebars 3 to rotate the front wheel 2 to the left, a centrifugal force is exerted on the user which tends to move him towards the outside of the turn. In order to compensate for this force, the user leans towards the inside of the turn, which has the effect of turning the rear wheels 5 in order to facilitate the rotation of the scooter for a given inclination of the platform 1.

[0043] This configuration is particularly effective because the user is installed standing on the platform and with his hands fixed to the handlebar 3. The median sagittal plane of the user is merged with the median longitudinal plane of the scooter. The same can be true for a scooter equipped with a seat fixed to the platform. As with a bicycle, the user who looks in front of him, also looks in the extension of the longitudinal axis of the vehicle, which allows for maximum observation quality with regard to obstacles which may be in his path. It is then easier to turn the scooter to avoid obstacles.

[0044] Installing the user with both feet side by side on the platform in a transverse direction perpendicular to the longitudinal direction allows the user to better manage the pushing forces on the right side or the left side of the platform. This allows better management of the inclination of the platform and therefore better management of the pivoting of the rear wheels around the first pivot axis. The user can lean to induce the pivoting of the platform and therefore the pivoting of the wheels. The user holds onto the scooter by means of the handlebar 3 which allows him to better balance.

[0045] Preferably, the scooter has at least one motor which rotates at least one of the front wheel 2 or the rear wheels 5. It is particularly advantageous for the motor to rotate the front wheel or at least the front wheel. The motor may be a hub motor.

[0046] At low speed, it is preferable that the pivoting of the platform relative to the ground plane which supports the wheels is low or zero. When stationary or at low speed, the low pivoting or absence of pivoting of the platform 1 relative to the ground plane allows the user to more simply remain with both feet on the platform 1.

[0047] Preferably, the scooter has a locking means which is configured to block or reduce the pivot angle of the platform 1 relative to the ground plane when the speed of movement of the scooter is lower than a threshold speed, for example lower than 10 km / h, more preferably lower than 5 km / h or even lower than 3 km / h. By reducing or preventing the pivoting of the platform at low speed, the stability of the platform is increased. A control circuit of the scooter can be configured to allow the pivoting of the platform 1 around the second pivot axis when the speed exceeds the threshold speed. Below the threshold speed, turns are mainly managed by the front wheel. Above the threshold speed, turns involve the inclination of the platform 1. For high speeds, it can be dangerous to perform a When turning with a small radius of curvature, the scooter can be steered by tilting the platform. For intermediate speeds, it is advantageous to combine the rotation of the front wheel 2 and the transverse tilt of the platform 1.

[0048] With a two-wheeled scooter, the lower the speed, the more difficult it is to have a stable platform, so it becomes preferable to stop and put at least one foot on the ground. With a three-wheeled scooter, the platform is more stable, but its ability to pivot the platform in order to turn the rear wheels is weak or non-existent, and this can lead to some difficulty in controlling turns when the speed increases. A configuration with larger wheels is then sought, which increases the size of the vehicle.

[0049] By using a locking means whose operation is linked to the speed of the vehicle, it is possible to modify the mechanical behavior of the pivoting member as a function of the speed in order to have a rear axle which is the most efficient for the speed range considered. For example, the locking means makes it more difficult or even impossible to pivot the rear wheels at low speed.

[0050] The locking means may have a rod which is mounted movably relative to the pivoting member 6 and which is intended to be inserted at least into one hole in the axle and into one hole in the body of the pivoting member 6. The rod is mounted movably between a first position where the rod is inserted into the hole in the axle and the hole in the body and a second position where the rod is at a distance from at least one of the hole in the axle and the hole in the body. Depending on the shape of the hole in the axle, the hole in the body and the shape of the rod, the first position may block the pivoting or reduce the amplitude of the pivoting. When the rod is pressed into the hole in the axle and the hole in the body, it prevents or limits the pivoting of the platform relative to the ground level which corresponds to the plane defined by the contact zone between the wheels and the ground.

[0051] The scooter may comprise a speed sensor which is configured to calculate the speed of movement along the longitudinal axis of the platform 1. The measured speed is compared to a threshold speed. If the speed is lower than the threshold speed, the rod is able to be in the first position. If the speed is higher than the threshold speed, the rod is in the second position.

[0052] When the speed is lower than the threshold speed, the rod reaches the first position when the axle hole and the body hole are aligned according to the direction of rod movement.

[0053] The speed sensor may comprise an accelerometer which measures the acceleration in the longitudinal direction to deduce the speed of movement. Alternatively or in addition, the speed sensor may comprise a spring mechanically connected to the axle and which deforms according to the rotational speed of the axle, for example in the manner of a tachometer.

[0054] In an alternative embodiment, the speed sensor is linked to a speed control command connected to the motor. The command is configured to define several distinct power setpoints which substantially correspond to distinct speeds. When the command is in a position corresponding to a power lower than a threshold power, the rod is able to be in the first position. When the command is in a position corresponding to a power higher than the threshold power, the rod is in the second position. This measurement can be coupled with a measurement of the inclination of the longitudinal axis relative to the vertical direction so as to better match the power delivered by the motor and the actual speed of the scooter.

[0055] It is particularly advantageous to provide that the rear part of the platform 1a is inclined and that the two rear wheels 5 are fixed to the inclined part by the pivoting member. It is particularly advantageous that the rear part is inclined upwards when moving from the front end to the rear end, that is to say that the rear end rises to move away from the ground plane.

[0056] The inclination of the rear part of the platform makes it possible to simplify the configuration of the fixing means between the axle and the platform. The pivoting of the axle in response to the transverse inclination of the platform relative to the ground simultaneously causes one of the rear wheels to move forward in the direction of the front wheel 2.

[0057] Depending on the configurations, the motor can be an electric motor or a thermal engine.

[0058] Preferably, the upper face of the platform 1 is inclined forward, that is to say that when the wheels are placed on a horizontal face, the upper face rises when the platform is observed in a direction which goes from the rear wheels 5 towards the front wheel 2. The inclination is observed in a median longitudinal plane which includes the vertical direction.

[0059] The angle of inclination is preferably identical or substantially identical to the angle which connects the axis of rotation of the front wheel and the rear wheels. The difference in diameter of the wheels as well as the spacing between the wheels are chosen to have an angle which is advantageously non-zero, preferably between 1° and 10°, more preferably greater than or equal to 3°.

Claims

Claims

1. Scooter comprising: - a platform (1) intended to receive a user, - a handlebar (3) mechanically connected to the platform (1), the handlebar (3) being pivotally mounted to steer the scooter - a front wheel (2) pivotally mounted and connected to the handlebar (3) by a steering rod (4) to form a front wheel (2) steered, the front wheel (2) being single and connected to the platform (1) by means of the steering rod (4); - two rear wheels (5) connected to the platform (1); characterized in that the two rear wheels (5) are connected to the platform (1) by a first pivoting connection allowing the two rear wheels (5) to pivot relative to a first axis so that one of the two rear wheels (5) approaches the platform (1) while the other of the two rear wheels (5) moves away from the platform (1), the front wheel (2) having a diameter greater than the diameter of the rear wheels (5).

2. Scooter according to claim 1 in which the two rear wheels (5) are connected to the platform (1) by a second pivoting connection allowing the two rear wheels (5) to pivot relative to a second axis so that one of the two rear wheels (5) moves closer to the front wheel (2) while the other of the two rear wheels (5) moves away from the front wheel (2).

3. Scooter according to one of claims 1 and 2 in which the two rear wheels (5) are fixed to two ends of a rotation shaft and in which the rotation shaft is fixed to the platform (1) by the first pivoting connection and possibly by the second pivoting connection.

4. Scooter according to any one of claims 1 to 3 in which the front wheel (2) is mounted in translation along a longitudinal axis of the steering rod (4).

5. A scooter according to any one of claims 1 to 4 wherein at least one of the first pivoting connection and the second pivoting connection is formed by at least one elastically deformable pad, the at least one pad deforming to pivot the two rear wheels (5).

6. Scooter according to any one of claims 1 to 4 comprising a speed sensor (7) configured to measure a speed of de- placement of the scooter along a longitudinal axis of the platform (1) and a blocker configured to reduce an amplitude or block a pivoting of the two rear wheels (5) around the first axis when the speed sensor (7) detects a speed lower than a threshold speed.

7. Scooter according to claim 6 when it depends on claim 3 comprising a pivoting member (6) defining the first axis allowing the pivoting of the platform (1) relative to the rear wheels to bring the rear wheels closer to or further away from the platform (1), the pivoting member (6) being provided with a body and an axle, in which the body and the axle respectively define a first hole and a second hole, the first hole being aligned with the second hole when the platform (1) is in a rest position, in which a rod is mounted movably between a first position where the rod is able to be inserted into the first hole and the second hole aligned and a second position where the rod is at a distance of at least one from the first hole and the second hole, and in which the rod is connected to the speed sensor to be in the first position when the sensor detects a speed lower than a threshold speed.

8. A method of using a scooter comprising the following steps: - providing a scooter according to any one of claims 1 to 6; - applying a greater vertical force to the right side of the platform than to the left side to pivot the platform (1) and bring the platform (1) closer to the right rear wheel (5) and to move the left rear wheel (5) away from the front wheel (2).

9. Method of using a scooter according to claim 8 comprising the step of decelerating until reaching a threshold speed, the platform (1) locking in a position where the two rear wheels (5) are substantially equidistant from the platform (1) in a vertical direction.

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