Gyroscopic Device For The Stabilization Of Laterally Unstable Vehicles

Abstract

The present invention is directed to a gyroscopic device for stabilizing a laterally unstable vehicle which rests on aligned contact points or on a very narrow surface which may be identified with a segment of a line. The device comprises a gyroscopic disc mounted on a swivelling support. The disc rotates in an oscillating plane according to the orientation of the support and according to the tilt of the vehicle. This plane is substantially parallel with the one passing through the line of the contact points of the vehicle with the travelling surface and the center of gravity of the vehicle. Its axis of rotation can never be parallel with the latter plane. The disc rotates even after the vehicle has stopped. It is rotated either by a wheel actuated by the movement of rolling surface of the vehicle either by an independent motor either by the propulsion motor. After the vehicle has stopped, the disc rotates through its own inertia, due to a free wheel mounted on the transmission. The stability device and the direction system may include a control system. It is particularly used for cycles, motorized or not, to vehicles sliding on snow or rough ground, to laterally unstable boats.

Description

The present invention is directed to cycles having two wheels which are motorized or not. More particularly, the invention is directed to a device which enables to increase the stability of a cycle whether the latter is in movement or is stopped temporarily. Such a device will also permit to regularize the energy which is necessary to operate the cycle.

The stability of a bicycle is assured above a satisfying speed. It is to be reminded that the gyroscopic movement which results from the conception of the vehicle with its wheels assisted by the movement of the hips acting on the center of gravity located above the points of contact with the ground, permit to obtain an acceptable equilibrium above a certain speed. With some vehicles, it is known to improve the stability at low speed or during a temporary stop, by means of a second gyroscopic system which operates independently of the propelling means of the vehicle. This supplementary stabilizing device which operates when the vehicle is at low speed or is stopped, should be an impediment when driving at a higher speed, because its effects would run the risk of deforming the natural inertia or the usual reflexes associated with the operation and propelling of the device. It would appear that the above disadvantages have prevented the search for solutions which are sure and efficient whether the vehicle is stopped or in motion.

It is also known to stabilize a cycle by means of lateral wheels, however these accessories are cumbersome and dangerous when the cycle is driven in traffic.

The device of the present invention enables to improve the stability of two-wheel bicycles when they are stopped as well as when they are moving slowly or rapidly, and to regularize the driving force of the cycle, the latter resulting from the pedals or from a motor in the case of a motor cycle. This second result is obtained by means of a single stabilizing gyroscopic wheel which stores a certain amount of energy when driving down hill and partially restores the same when going uphill. These conjugated results are due to the specific drive of the gyroscopic wheel. The latter is mounted concentrically with respect to the front wheel, which fact is well known in the art. However, the driving mechanism of the gyroscopic wheel which consists of a pawl system (or freely rotatable wheel) operates only when in rotation and comprises belts and pulleys which are arranged especially for slipping (flexible clutch) and defines a way of restoring to the front wheel the energy which has been stored in the gyroscopic wheel when driving at high speed. The belts can easily be replaced without dismantling the wheel. In other words this device including belts and planet pulleys produces two effects: the first one contributing to better overcome the supplementary inertia of the gyroscopic wheel when starting the vehicle; the second effect enabling to better recuperate the energy which has been stored by the said gyroscopic wheel (for example when going downhill) when the vehicle slows down (for example when going uphill).

In the drawings which illustrate the invention:

FIG. 1 is a partial half section through the axis of the wheel provided with a stabilizing device.

FIG. 2 is a schematic view on the right-hand side of the wheel.

FIG. 3 is a schematic view on the right-hand side according of the cross-section A - A shown in FIG. 1 and illustrating the essential arrangement inside the wheel.

FIG. 4 is a schematic decomposition in the plane x -- x' z -- z' of the main parasitical, and precession couples accord-ing to the embodiment described.

FIG. 5 is a decomposition of the re-establishment forces of the tilt in the case of FIG. 4.

FIG. 6 is a schematic representation of the couples in the case wherein the disc is spaced from the vertical plane of equilibrium and in parallel relationship.

FIG. 7 is a decomposition of the efforts in the plane x -- x', z -- z'.

FIG. 8 is a schematic representation showing the couples in the case wherein the axis of the disc is parallel to the axis y -- y', that is, practically horizontal.

FIG. 9 is a schematic representation showing the couples in the case wherein the axis of the disc is practically vertical.

The device essentially comprises a disc 1, which may be perforated, approximately in the longitudinal median plane of the wheel. It is rigidly secure to a tube used as a bearing for a ball bearing 3 and 4, rotating about an axle of the wheel 5. The latter is freely mounted on the ball bearings 6 and 7 on the axles formed by a fixed rod 8, rigidly supported by the fork 9 or support of the direction. At one end of the tube 2, is fixed a pulley 10 having a double throat, which directly drives the disc 1.

Solidly fixed to the wheel through the disc 11 on which is mounted a row of spokes, the bearing 12 of the axle 13 enables the latter to freely rotate. The said axle 13 combines and synchronizes the two pulleys 14 and 15 having different diameters, the said pulleys operating in a planetary arrangement. The pulley 15 drives, the pulley 10 through a set of belts conveniently crossed. The pulley 14 is equally driven by belts through the pulley 16 which is coaxial with the wheel of the cycle and the disc, that is, with the axis x -- x'. The said pulley 16 is mounted on the axle 8 to a driving wheel in a single direction of the free wheel type 17. The inner part 18 of the latter is therefore fixed. The pulley 16 freely rotates in a clockwise direction for an observer seeing the vehicle passing from the right to the left, or what is identical in the direction indicated by the arrow 19 in FIG. 2. The said pulley 16 cannot rotate in the reverse direction of the arrow. For a purpose of equilibrium, there may be two trains of pulleys 14 and 15 which are diametrically opposed on the disc 11.

When the vehicle starts to rotate, the wheel rotates in the direction of the arrow 20. It drives the disc 11, the two trains of pulleys 14 and 15, their axle 13 rotating around the axis x--x' according to the direction 21. According to this fact, the pulley 14 will rotate in the direction of the arrow 22, because the free wheel 17 will be at rest. The disc 1 will pivote around the axis x -- x' at an angular speed which is greater than the wheel and in the direction of the arrow 23. In fact, the belts 24 and 25, being crossed, to the speed of the wheel transmitted to the disc, would be added the one of the relative rotation of the axle 13 amplified by a ratio of the diameters of the pulleys 14 - 15 and 10.

When the wheel slows down or stops, the revolution of the axle 13 around the axis x -- x' slows down or stops. It results from this, that the disc 1 continues its rotation substantially by keeping the same speed (due to its inertia). In fact, the free wheel 17, is then driven in its outer part in the direction of the arrow 19, successively by the pulley 10, the pulley 15, and the pulley 14. Only the friction which is very weak is opposed to the free rotation of the disc 1.

The result of this combination is to maintain the latter in rotation, while the vehicle slows or stops. The use of belts, and preferably round belts, enables to obtain a sliding effect when it starts. The forces are then limited, the progression of the speed of rotation of the disc 1 being slower and the inertia of the assembly being more easily mastered. Instead of using a belt, it is possible to use a transmission box with smooth coupling, such as magnetic, hydraulic, frictional, pneumatic or other trans-missions systems. A setting of the smoothness of the coupling may also be mounted.

On the other hand, it will be seen that there is a phenomenon by which energy is stored when driving downhill and said energy is partly recuperated when driving uphill, because when the rotation of the front wheel (FIGS. 2 and 3) is slowed down such as when the vehicle decelerates, the speed of the gyroscopic wheel does not decrease in the same proportion because of its inertia. The pulley 10 then becomes the driving pulley. The resulting couple acts on the belts 24 and 25. The friction forces which have a tendency to slow down the rotation of the axle 13, and therefore of the pulleys 15 and 14, produce a force of reaction on the bearing of the axle 13, the said reaction giving rise to a motor couple which acts on the disc which is solid with the front wheel. The frictions in the free wheel 17 have also a tendency to slow down the rotation of the axle 13 and have the same effects. It is obvious that all these frictions appear when the gyroscopic wheel 1 starts to accelerate, for example going downhill; however, the energy is then supplied by the vehicle itself which is dragged down by the slope, said vehicle not requiring the same kind of braking by the brake shoes (energy completely lost). The frictions caused by the rotations of the pulleys 14 and 15 about their own axes can be measured by means of rings mounted on the bearings 12 or even on the free pawl wheel 17.

It should also be noted that the belts 24 and 25 can easily be dismantled and replaced without dismantling the front wheel. It is only sufficient to remove them from over their respective pulleys in order to recuperate them.

It should also be noted that the planet pulleys 14 and 15 are diametrically opposed in order that the efforts be well distributed around the axis of the wheel of the cycle. Similarly, the two belts 24 and 25 are mounted symmetrically with respect to the diameter extending through the axes 13.

Immediately after the vehicle has stopped, the device for recuperating the energy of the gyroscopic wheel which rotates by its own inertia, tends to move the cycle forward. This has no importance since it is only sufficient to keep the brake tight as long as the gyroscopic wheel rotates, said gyroscopic wheel enabling to improve the stability when the vehicle has stopped.

The consequences of this device will now be examined on the stability of a vehicle. FIG. 4 schematically represents a disc 1 rotating in the direction of the arrow around its axis x -- x'. It is illustrated in the plane 26 passing through its center O and the lines of contact points y -- y' of the wheels on the ground. The fork, that is, the support, adapted to swivel by the steering handle of the rotation axis x -- x' of the said disc 1, pivots around the axis z -- z'. This movement which is produced in the direction of the arrow 27 drives a couple around the axis y -- y', and this in the direction of the arrow 27 (precession), according to the known laws of the gyroscope. This couple according to the arrow 28 produces around the resting points of the vehicle, constituted by the axis y -- y', a couple according to the direction 29, through the fork 9 and the frame of the cycle. While decomposing the forces which are then created, on FIG. 5, one can see that a composing force appears in 30 according to the axis x -- x' which tends to tilt the vehicle towards the right (FIG. 5).

Therefore, if the vehicle tilt, towards the left (FIG. 5) a movement of the steering handle, in the counterclockwise direction, seen from above by the conductor, will compensate the said tilt and straighten up the vehicle. It is pointed out that, if the gyroscopic disc happens to be in a plane 31 (FIG. 6) which is parallel to the plane 32 passing through the axis y -- y' and the center of gravity 33 of the vehicle, the effect of the movement on the fork mentioned above will be the same. FIG. 7 shows a decomposition of the forces in the plane formed by z -- z' and x -- x', that is, perpendicular to the axis y - y'. It is also pointed out that if the axis x -- x' is in an equilibrium position and inclined horizontally relative to the plane O, y -- y', the movement of the fork around the axis z -- z' according to the arrow 27, equally drives a precession. But the axis of precession Y -- Y' rotates with x -- x'. The couple which builds up around Y -- Y' has a tendency to tilt the vehicle towards the front, which is detrimental to the lateral stability effort. In an extreme solution, if the axis x -- x' is parallel to y -- y', there is no possible stability (FIG. 8).

If the axis x -- x' is inclined towards a too vertical position, the precession couple around the axis Y -- Y' will always tend to stabilize the vehicle. In an extreme position, if the axis x -- x' is vertical, FIG. 9 shows the relationship between the couples. But in this case, z -- z' becomes perpendicular to the plane O, y -- y'. It results that in upward or downward slopes, a parasitical oscillating movement, around the axis z -- z' produces a parasitical precession couple around Y -- Y' which tends to produce an unfortunate tilt of the vehicle, while the driver would prefer to follow a straight line. This observation leads to some difficulties which may result in the impossibility of driving the vehicle at a fast speed.

As a conclusion, only the positions of the gyroscopic disc 1, represented on FIGS. 4 and 6 will satisfy at the same time the stability while in motion or stopped, in conformity with the desired result. It is understood that the relatively weak inclination of the axis x -- x' relative to the vertical plane passing through the center of gravity of the vehicle and the line y -- y' may even be acceptable.

The fact of driving the cycle with a motor which acts directly or indirectly on one of the front or rear wheels (known in the art), is not relevant to the mounting of the device according to the invention. The same stability and regularizing of the motor energy are obtained.

Claims

I claim:

1. A gyroscopic device for stabilizing and regularising the propelling energy in a two-wheel cycle, said device being mounted on said two-wheel cycle and comprising two trains of planet groove pulleys, a disc solid with the front wheel of the two-wheel cycle, said two trains of planet groove pulleys pivotally mounted on said disc, said trains of pulleys both being parallel to the front wheel of the cycle and mounted equidistant to the center of said front wheel of said cycle, a bearing mounted on said disc each of said trains of pulleys pivoting on said bearing, a shaft solid with said bearing each of said trains of pulleys being mounted on said shaft and comprising a double groove pulley which is connected by means of belts with a drum which is solid with a gyroscopic wheel, said gyroscopic wheel freely rotatable over the axle of the front wheel of the cycle, and a simple groove pulley which is connected by means of a belt to a third pulley which is fixedly mounted over the wheel, by means of a pawl.

2. Device according to claim 1, wherein the two belts connecting the drum which is solid with the gyroscopic wheel and the two double pulleys are mounted in such in manner that the drum is inside the path of each of said belts, thus enabling a rapid change over of the latter, said belts being mounted symmetrically with respect to the diameter passing through the axes of each of the two trains of planet groove pulleys.

3. Device according to claim 2, wherein each of the belts is mounted with a predetermined tension and a low winding angle of about 90.degree. around the said drum in order that it can slip when starting said cycle.

4. Device according to claim 1, wherein the bearing carrying the axle of each of the planet pulleys comprises a friction controlled ring adapted to transmit to the wheel of the cycle by means of the pulleys and belts, the energy which has been stored by the gyroscopic wheel of the vehicle.

5. Device according to claim 1, wherein the belt which connects the two planet pulleys and the third pulley mounted on the freely rotatable pawl, is mounted with a predetermined tension and with a winding tension lower than 90.degree. about the said ring.