THRUST DEVICE FOR VEHICLES IN GENERAL

Technical Field The present invention refers to the technical field of engines for land crafts in general. In particular it refers to a device able to cooperate with an engine, as for example explosion, electric or gas engines, optimising the thrust on equal terms of the consumptions. It is also described a realization method of the present invention.

State of the Art

Since a long time are known engines for land crafts in general, as cars, buses or trains, which are operated and moved by engines of different nature depending on the cases. It is know how, for example, the cars use common explosion engines of fuel, diesel or gas type. In this case, the fuel liquid is required to operate the explosion that moves a piston. Obviously, independently from the fuel used, the quantity of consumption depends on many factors as the travelling speed, the route and others.

Indeed it is known how, in the urban traffic, the consumptions increase noticeably despite the reduced speed, as the driver is forced to keep the revs per minute highly reduced (low gears) . On the contrary, in the high speed streets, the consumption is more contained, but on the condition that the distances to cover are not excessive and the kept speeds are anyway sufficiently far from the speeds limit of the car.

At the moment, the only way that allows a consumption saving is represented by the type of engine selected and by the realization technology of the same beyond the type of driving of the same vehicle. It is indeed known how a diesel engine consumes less than a fuel engine but to the detriment of the efficiencies. It is also well known how it is possible to economize the consumption with a tranquil driving which do not submit the engine to excessive efforts. Moreover lately are used always more the gas plants which, despite they do not have high performances, allow a big saving in the costs. In any case, the innovative materials that are everyday lighter allow a reasonable weight containment and a consequent fuel saving.

However, despite that, the lowest consume of fuel is always bounded to the type of selected engine (often renouncing to the efficiencies of the vehicle) together to the kind of driving of the same vehicle (as for example driving fast or tranquil) .

The use of electric engines seems today to be a new limit to allow a saving in the fuel's costs, beyond to a definitive resolution to the pollution. Despite that such engines are anyway used, nowadays, exclusively on public means of transportation as for example trains, even if lately are realized different prototypes destined to the private use.

Also in this case, anyway, we are still forced to undergo to an excessive consumption of predetermined electric power, which can only be limited through a controlled and limited use of the vehicle beyond the fact that the driving is not excessively sporty.

Disclosure of invention It is therefore the aim of the present invention to give an auxiliary engine thrust device that allows to reduce the consume without necessarily having to intervene on the type of engine selected or on the driving of the same . These and other aims are reached by the present land vehicle in general, as cars, trains motorcycles and similar, and comprising an engine (4) having at least a driving shaft (3) connectable to the tyres to transmit a rotation and realize the advancing motion and characterized by the fact that the vehicle comprises:

- At least an aeolic propeller (2) operatively connected to the driving shaft (3);

- Means (5) to connect operatively the propeller to the driving shaft; and where the propeller is drag in rotation by the air flow realized by the advancement motion of the vehicle to cooperate through said means with the rotation of the driving shaft (3) . In this way the advancement motion of the vehicle through a common electric or fuel engine, is used with the aim to lighten the workload of the same engine. Indeed the propeller, placed against the advancement direction, will be hit by the air flow and will contribute through its rotation to help the engine. In this manner it is used the passive energy transforming it into active energy collaborating with the engine.

Then with the aim to connect the propeller to the driving shaft, the above means comprise a shaft (6) and a sprocket (9; 209) . In this manner the shaft (6) can be connected at one of its free ends to the propeller and at the opposed end to the sprocket. In turn the sprocket, is keyed to the driving shaft. In particular the sprocket can be contained within a gearbox 8 eventually containing gears to change opportunely, if it is necessary, the numbers of revolutions of the propeller and of the driving shaft.

According to a first possible constructive embodiment of the invention, particularly simple, it is expected that the sprocket (9) comprises a first (10) and a second cylindrical body (11) that are annular and placed coaxially one inside to the other. In particular the second cylindrical body (11) comprises an internal surface (16) coupling to the first cylindrical body (10) with predetermined shape and comprising a plurality of sites

(17) while the first cylindrical body (10) comprises a plurality of teeth (12) that are hinged at one end around the external surface and are projecting in a radial manner toward the outside to bind within the respective sites (17) . Springs (13) or similar maintain the protracted position of the teeth in such a manner that there is a permanent contrast of the same teeth against the profile of the internal surface (16) . In this manner, in correspondence to a number Ni of revolutions of the first cylindrical body (10) greater than the number N2 of the second cylindrical body (11), the teeth (12) are bounded within the respective site (17) pulling into rotation said second cylindrical body. Vice- versa, in correspondence to a number N2 of revolutions of the second cylindrical body (11) greater or at least equal to the number Ni of revolutions of the first cylindrical body, the profile (16) of the second cylindrical body (11) slides on the back (15) of the teeth (12) determining their oscillation around their respective hinge (14) . In this way said second cylindrical body (11) freely rotates respect to said first cylindrical body (10) .

It is clear how such solution is constructively simple making possible couplings and uncouplings of a cylinder respect to the other depending simply on the respective angular speeds. Indeed by making integral the first cylindrical body (10) to the propeller and the second cylindrical body 11 to the engine it is possible to realize a dragging of the propeller on the engine in the conditions where the propeller rotates more rapidly than the engine. In the contrary, being the propeller passive, the device gets automatically uncoupled making idle the shaft of the propeller respect to the driving shaft. A second solution that is constructively more complex comprises on the other hand a sprocket (209) integral to the shaft of the propeller (6) and that comprises a crosshead coupling on the driving shaft. The sprocket is realized movable from a coupling position, where it is bounded on the driving shaft in correspondence of a predetermined number Ni of revolutions of the propeller greater or equal to the number N2 of revolutions of the driving shaft, and a resting position where it is unbounded from the driving shaft 3 in correspondence to a number Ni of revolutions of the propeller lower than the number N2 of revolutions of the engine.

In particular are comprised actuators (218) to control the movements of the sprocket, said actuators being controlled by an optical reader predisposed in use to detect the number N2 of revolutions of the shaft (6) .

Also according to this solution it is thus possible to uncouple the propeller and the shaft 6 from the driving shaft 3 any time the propeller has a number of revolutions that is too low. Obviously equivalent devices for manual control of the actuation/uncoupling can be applied.

Advantageously the shaft has a predetermined length such to allow the down-flow of the air behind the propeller. In this manner it is left an exit to the air behind the same propeller, allowing an efficient functioning.

According to a possible constructive solution of the vehicle, the engine is an explosion engine and is placed on the back part of the vehicle, while the propeller is placed on the front part of the vehicle.

Alternatively the engine can be an electric engine which is placed on the back part of the vehicle and/or underneath the driver's chair, while the propeller is place on the front part of the vehicle.

These solutions creates wide spaced of exit for the air on the front part where it is placed the propeller.

In both solutions are anyway comprised air outlets to direct the flow that hits the propeller towards the outside of the vehicle.

In this manner, the suck in Venturi effect by depression of the air will favour the rotation of the propeller and will reduce the drag.

For such aim, the outlets comprise a conveyance path of the fluid towards the lateral and/or back part of the vehicle .

Moreover the propeller is positioned on the front part of the vehicle in correspondence of its nose.

Obviously other constructive solution can comprise also to propellers coupled to the shaft by means of a driving belt or similar or also more than two propellers.

Without moving too far from the present inventive concept, opportune changes on existing vehicles can allow to assemble the present device, without having to buy a new vehicle. For such aim it is then possible to comprise an auxiliary thrust device for land vehicles in general, said vehicle comprising an engine having at least a driving shaft connectable to the front and/or back axis of the tyres to transmit the rotation and realize an advancing motion of the vehicle and characterized by the fact that said device comprises:

- At least an aeolic propeller ' (2) operatively connected to the driving shaft (3) ;

- Means (5) to connect operatively the propeller to the driving shaft; and where the propeller is dragged in rotation by the air flow realized by the advancement motion of the vehicle to cooperate through said means with the rotation of the driving shaft (3) .

It is described also a method for the realization of the rotation of a driving shaft of an engine for vehicles in general and comprising the activation operation of the engine and further transfer of a torsional moment to the shaft and characterized by the fact that a part of the torsional moment is transferred by means of the rotation of at least a propeller hit by the advancement flow of the vehicle and operatively connected to the shaft through means 5, said means transferring to the shaft the torsion received by the propeller.

Advantageously the torsion transmitted from the propeller to the shaft is proportional to the advancement speed of the vehicle.

Brief description of drawings

Further features and advantages according to the invention, will be clearer with the description of one of its pattern realization that follows, made to illustrate but not limit, with reference to the annexed drawings, in which:

- Figure 1 schematically represents the constructive solution according to the invention.

- Figure 2 represent a detail of the propeller-shaft coupling and means to allow the torsion transfer on the driving shaft according to a first preferred embodiment. It is highlighted a detail section of the sprocket.

- Figure 3 represents the functioning of the sprocket to pull into rotation or to get uncoupled from the driving shaft. - Figure 4 represents a second possible solution of the sprocket propeller and driving shaft coupling.

- Figure 5 schematically represents the aspiration and the air outlet that activate the fan.

Description of a preferred pattern realization With reference to figure 1, it is described as an example and not in a limitative manner, a common vehicle that assembles a device 1, according to the present invention. A fan 2 is prearranged in correspondence to the front part of the car in correspondence to the nose. The propeller is directly connected to the driving shaft 3 of the engine 4 through opportune means 5 that allow to transmit the torsion of the propeller to the shaft. In particular the means 5 comprise a connection shaft 6 that connects the driving shaft 3 to the propeller and a sprocket 9 (represented in figure 2) opportunely contained within a gearbox 8.

As described in detail of figure 2, the gearbox 8 contains a keying to connect the shaft 6 exiting the propeller to the driving shaft 3 and for such aim inside it is therefore prearranged a sprocket 9.

According to a first constructive solution, the sprocket 9 comprises a first cylindrical body 10 coaxial to a second cylindrical body 11 both annular and rotating one inside the other (only to clarify figure 2 represents them as not coupled) . In particular the internal body 1 is realized integral or firmly coupled to the shaft of the propeller 6 while the outer one 11 results integral to the driving shaft 3. The internal cylindrical body 10 comprises a plurality of teeth 12 hinged at one end 14 around the same cylinder and extended radially towards the outside of the same surface by means of common springs 13. The term radially is to be intended in a generic manner, or rather towards the outside of the cylindrical surface. In such manner the teeth, if opportunely squashed towards the cylindrical body 10 in correspondence of their back 15, exceed the traction force of the spring and lay down on the same surface. For such aim the surface 10 can comprise some insertion sites not represented in the figure just for simplicity. The internal surface 16 of the cylinder 11 has a shape that approximately repeats the profile external to the annular cylindrical body 10. In such manner an equivalent number of grooving or sites 17 are required to bind the teeth of the internal cylinder 10 respect to the external one 11, in such a way that the external body can be dragged by the rotation of the internal body. In particular (look at figure 3) when the external cylinder 11 rotates faster respect to the internal cylinder 10 (N2 > Ni) , the grooving 17 slide on the profile 15 of the teeth which, being permanently in contact against the profile 16, lower and raise by effect of the springs without bounding. In such manner the external cylinder 11 rotates freely (or rather the engine) without having to drag the propeller (or rather the internal cylinder 10) found in the passive state (slower or even still) . In the contrary where, on the other hand, the internal cylinder 10 rotates at the same speed or faster than the external cylinder 11 (N2 > Ni) , in such case then the teeth 12 will bind in the respective grooving 17 dragging the external cylinder 11 into rotation a the speed of the internal cylinder. A second constructive solution (look at figure 4) comprises on the other hand the sprocket 209 realized in a sole piece and opportunely shaped (in this case in a star shape) . In such manner can be bounded on the ends of the shafts (3, 6) dragging this way the driving shaft 3 into rotation when this results to be engaged on it. In particular the sprocket can be realized integral to the shaft 6 and with a crosshead coupling on the driving shaft 3. According to this solution, thus, the sprocket along to the shaft 6 is realized movable between a coupling position where it gets bounded on the driving shaft in correspondence of a predetermined number of revolutions Ni of the upper propeller to the number of revolutions N2 of the engine and a resting position in correspondence to a number of revolutions N2 lower than Ni where it is uncoupled from the driving shaft 3. In this manner, when the propeller is passive and similarly to what is been said previously, it is possible to uncouple the shaft from the propeller avoiding that this gets dragged by the engine.

With the aim to make the sprocket movable, any translation device can be comprised. In particular figure 4 schematically represents a common lever device 218 (for example hydraulic actuators) which command the translation of the sprocket shaft group in function to a number of revolutions of the propeller. The number of revolutions (and thus the movement of the actuators) can be read by a common optical sensor that commands the activation of the lever device activating the movement from\towards the driving shaft.

In order to allow the correct down flow of the air behind the propeller (avoiding turbulences that can impede its rotation) , it is necessary to prearrange it with a sufficient light. For this reason it is for example comprised (look at figure 1) a constructive solution where the engine is placed on the back part of the vehicle. In the case of electric engines, there can be comprised different positioning, as for example underneath the chair, given their greatly reduced dimensions. In this case thus it is realized a sufficient light for the air circulation.

In order then to comprise a better down flow of the air, appropriate outlets (look at figure 5) direct this towards the lateral, lower or back parts of the same vehicle. Without moving from the present inventive concept, it is also possible to comprise a number of propellers grater than one and placed in different positions. For example two or more propellers can be placed side by side to each other and connected through belt to the shaft 6.

Obviously the undertaken figures describe an application of the invention to the sole cars, but any- other land vehicle can be realized or modified according to what has been described and without having to move apart from the present inventive concept. Moreover different positioning of the propeller can be realized (therefore not only frontally) without having to move from the present inventive concept. It is briefly described the functioning of the present invention. The engine, being an explosion, electric or of any other kind, activates usually the vehicle and allows this way its functioning. In such manner the propeller (placed for example frontally) is dragged into rotation by means of the torsion generated by the air flow realized by the advancement motion of the same vehicle. The rotation of the propeller contributes, through the torsion transferring through the means 5, to the rotation of the driving shaft 3. The first preferred configuration, constructively simpler, couples and uncouples automatically the driving shaft from the shaft of the propeller in function to the respective rotation speeds .

It is thus at this point clear how all the aims of the present inventing have been reached. In particular it is clear how the rotation of the propeller allows greatly to lighten the work force of the engine. The consequence is a remarkable increase of the energy saving in terms of consumed fuel.

The above description of a specific shape is able to show the invention from the conceptive point of view, in a way that others, by using the art, can modify and/or adapt in different applications this specific shape without any further research and without going apart from the inventive concept, and, therefore, it is intended that these adaptations and transformations will be considered as equivalent to this specific realization. The means and materials to make the many described functions can be of various nature without exiting the area of the invention, it is intended that the expressions or the terminology used have a simple descriptive aim and therefore not limiting .