COMPRISING SAID FRAME"

DESCRIPTION

The present invention relates to a frame and to a relevant cycling vehicle.

In the present description and in the following claims the term "cycling vehicle" means all these vehicles equipped with at least two wheels and comprising propulsion means driven by human muscular force, usually by means of pedals connected to a drive wheel by a drive chain. In some instance the cycling vehicles subject matter of the present invention, can be provided also with a mechanism for the so called "assisted pedalling" which, depending on the case, can comprise an electric motor supplied by a battery or a flywheel with a spring.

As it is known currently there are several types of cycling vehicles, such as for instance bicycles, tricycles, tandem bicycles or other types, which comprise two or more wheels, a seat for each rider (one or more riders depending on the vehicle) and a crankset.

Here the term "crankset" means a set comprising a pair of pedals and one or more pinions rotationally integral therewith, by means of which a rider can apply the drive torque necessary to move the vehicle forward.

A particular type of cycling vehicles is the so called "tandem bicycle", namely bicycles whose frame comprises (at least) two pedalling positions for just as many people.

Each pedalling position in turn comprises a crankset and a seat, aligned along the frame, one behind the other: each rider on the tandem bicycle acts on his/her own crankset that engages a respective chain for transmitting the motion to the rear wheel.

The front, steering wheel, is steered by the handlebar grasped by the rider sitting on the front, that is on the seat closer thereto, while the other rider, the one sitting on the back, uses a fixed handlebar on the frame as a support. The frame of the tandem bicycle develops symmetrically relative to a longitudinal median plane passing by the axis of the steering handlebar and the rear wheel.

Due to the configuration of such vehicle, the front rider is sat exactly in line with the rear rider, with the drawback that the latter does not see the road ahead clearly and therefore, in order to enjoy the view, the rear rider must turn the head sideways, with a posture not suitable for a cycling activity.

Moreover, due to this reason, the rear rider that desires to look the road ahead, must lean the torso sideways, with the risk of throwing the vehicle off balance.

What just described is valid also for cycling vehicles with three, four or more seats, which are made like tandem bicycles described above, except that the frame is longer and it houses a greater number of aligned pedalling positions.

Even in this case drawbacks are substantially the same, and possibly they are even made worse due to the greater number of riders.

Therefore the aim of the present invention is to provide a cycling vehicle able to overcome the above outlined drawbacks.

The idea underlying the present invention is to provide a frame for a cycling vehicle, where at least a first and a second pedalling positions are provided offset from each other relative to a direction of forward motion of the vehicle, the two positions being arranged at the opposite sides relative to a longitudinal median plane of the frame.

Thus, advantageously, the person sitting on the back of the vehicle will see clearly ahead by remaining properly sat on the seat and without the need of leaning sideways, since the front rider is in a position laterally offset from it.

In a particularly advantageous embodiment, the front steering wheel and the drive rear wheel of the vehicle are also offset from each other, relative to the same plane. Considering that such vehicle is mostly used for tourism reasons, namely for a non competitive use, its speed is very low, about at most 30-35 km/h, and therefore the feature of having offset pedalling positions and/or wheels do not lead to serious drawbacks when riding.

The features of the frame according to the present invention and those of the cycling vehicle where it is used, are a specific subject matter of the annexed claims.

These features and other advantages of the present invention will become more evident from the description of an embodiment thereof shown in annexed drawings, provided for clarifying and not limiting purposes wherein:

Fig.l is a side view of a first type of vehicle according to the present invention;

Fig.2 is a view from the behind the vehicle of fig.1 ;

Fig.3 is a top view of the vehicle of the previous figures;

Fig. 4 is a side view of the frame of the vehicle of the previous figures;

Fig. 5 is a top view of a first variant of the vehicle of fig. 1;

Fig. 6 is a top view of a second variant of the vehicle of fig. 1.

With reference to figs. 1-4 a cycling vehicle 1 according to the present invention is shown therein.

It comprises a frame 2 with two wheels mounted thereon: a front steering wheel 3 a and a rear drive wheel 3b.

The vehicle 1 further comprises two pedalling positions: a front one 4a, close to the steering wheel 3a and a rear one 4b, close to the drive wheel 3b; here and below the terms "front" and "rear" are used with reference to the direction of forward motion of the vehicle 1 in the normal forward traveling direction.

Each pedalling position 4a, 4b comprises a seat, 5 a, 5b respectively, and a crankset 6a, 6b operating the drive wheel 3b by a suitable kinematic transmission to which reference will be made later.

In the example shown in figs. 1-4, and with a particular reference to figs. 2 and 3, it can be clearly seen that the first pedalling position 4a and the second pedalling position 4b are offset from each other relative to a longitudinal median plane P of the vehicle.

Thus the rider sitting at the rear pedalling position 4b is able to see ahead clearly in the direction of forward motion of the vehicle 1 , since the rider sitting at the front pedalling position 4a is not in front of him/her.

In this example it has to be noted that even the wheels 3a, 3b are offset from each other, namely in the linear traveling condition (that is with the handlebar in the straight condition) the equatorial plane of symmetry of a wheel (that is the one perpendicular to its axis of rotation), does not coincide with that of the other one.

It has to be further noted that in this linear traveling condition, each pedalling position 4a, 4b is aligned with the median plane of the closer wheel 3a, 3b: the front pedalling position 4a therefore is aligned with the front wheel 3 a (obviously when the latter is not turned) and the rear pedalling position 4b is likewise aligned with the rear wheel 3b.

As a consequence of this particular condition, the weight of the two riders on the vehicle, each one sitting at his/her own pedalling position 4a, 4b, is mainly released on the wheel which is closer to the seating plane, thereby reducing the possibility of throwing the vehicle 1 off balance sideways and such that it is more easy to ride it in a turn.

This is even more real considering that the cycling vehicle 1 is mainly intended for purely tourism purposes, that is with low speeds that make the adverse effects when riding in a turn, resulting from the wheels being not aligned with each other, slightly perceptible and substantially they do not lead to any trouble.

The same is valid also for the resistance to forward motion, that at the low cruising speeds of a tandem bicycle is not affected by the fact that people riding it are offset from each other.

Thus, advantageously, the two riders can both look in the direction of travel of the vehicle, without requiring the rear rider to lean.

With reference to the part relating to the transmission of the motion from the cranksets 6a, 6b to the rear drive wheel 3b, it is noted that the kinematic transmission of the vehicle 1 in the shown example comprises three chains of the type for bicycle (and known per se) 7a, 7b and 7c, two rings 8a, 8b, three intermediate gears 9a, 9b, 9c and a set of sprockets of the gearing assembly 9d.

More in details, the front chain 7a meshes with the ring 8a of the crankset 6a of the first pedalling position 4a, such that the movement of the crankset 6a rotates the ring 8a and the latter correspondingly drives the chain 7a.

In a position aligned with the first ring 8a and with the first chain 7a, and meshed with the latter, there is provided a first gear 9a rotationally integral with a second gear 9b, being mounted on a shaft common with it..

The second gear 9b meshes with the second chain 7b, which is aligned therewith and with a third gear 9c.

The latter transmits the motion received from the chain 7b to the second ring 8b, which is associated also to the crankset 6b of the rear pedalling position 4b.

The second ring 8b meshes with a third chain 7c that in turn meshes with one of the sprockets of the gears of the gearing assembly 9d: the latter is of the type known per se in the cycling field and it comprises a set of sprockets having different diameters, such that it is possible to select the most suitable gear down ratio for the pedalling.

Obviously, as an alternative, it is possible for the vehicle not to be provided with any type of gearing assembly: in this case it will be provided only with one sprocket rotationally integral with the rear wheel.

The operation of the vehicle 1 described above is as follows.

The drive torque exerted by means of the crankset 6a by the person sitting in the first front pedalling position 4a, is transmitted to the ring 8a and from it, by the chain 7a, to the first gear 9a, that then transmits it to the second gear 9b, fitted to the same shaft.

Therefore the drive torque is transmitted from the second gear 9b to the third intermediate gear 9c by the second drive chain 7b.

The third gear 9c therefore transmits the motion to the second ring 8b, upon which also the crankset 6b of the second pedalling position 4b acts.

Finally, the two drive torques (i.e. the one generated by the crankset 6a and the one generated by the crankset 6b) are therefore transmitted from the pinion 8b to a sprocket of the gearing assembly 9d and from it to the rear drive wheel 3b.

The provision of the three chains 7a, 7b, 7c, of the two rings 8a, 8b, and of the three intermediate gears 9a, 9b, 9c is necessary in order to preserve the proper alignment of the chains connected to the pedals 6a and 6b with the sprocket of the gearing assembly 9d: it has to be noted that chains 7a and 7c connected to the first and to the second crankset are offset from each other and parallel to each other.

The fact that the two pedalling positions 4a, 4b and the wheels 3a and 3b are offset causes the pinions 8a and 8b not be aligned one with the other, and therefore the provision of the linkage comprising the first chain 7a and the three intermediate gears 9a, 9b, 9c allows the second drive chain 7b to properly operate which is so aligned with the sprockets of the gearing assembly 9d.

Now with reference to the frame 2, fig.3 shows the fact that it is asymmetrical relative to a longitudinal median plane, as on the contrary is for the known solutions of the prior art, but it is composed of three portions: a front portion 2a, associated to the front wheel 3a and where the first pedalling position 4a is provided, a second portion 2b, associated to the rear wheel 3b and where the second pedalling position 4b is provided, connected by a connection section 2c that, in the plan view, is curvilinear.

The fact that the frame is curved in the connection section 2c is necessary in order to offset both the wheels 3a and 3b and the pedalling positions 4a and 4b, as described above.

With reference now to fig.4, it shows a side view of the frame 2 described above.

In the shown example the frame comprises a front inclined post 21a and a rear inclined post 21b.

The upper portion of each post 21a, 21b can be associated at the top to the corresponding seat 5a and 5b and in the lower part a sleeve 23a, 23b is provided upon which the bearings of the shaft of each pair of pedals 6a, 6b are arranged, according to arrangements known per se in this field and no further reference is made thereto.

Then the frame 2 comprises a front cross bar 24a and a rear one 24b.

The two cross bars 24a and 24b, as it can be seen in the top view of fig.3, are not aligned one with the other, but they follow parallel straight lines, such to achieve the condition with the offset pedalling positions described above.

A fixed handlebar 22b is mounted on the rear cross bar 24b acting as a support for the person sitting in the rear pedalling position 4b; the fixed handlebar 22b is not aligned with the steering handlebar 22a which operates the fork 29 of the front steering wheel 3 a.

The rear triangle 28 supporting the sleeve for the bearings of the rear wheel 3b is connected to the rear post 21b.

It has to be noted that the sleeve 23a of the front post 21a is connected to the cross bar 26 by the tie rod 25; the cross bar 26 is connected at one end to the steering tube 29a and at the opposite end to the sleeve 23b, and it has a central curvature, as it can be seen in the top view of fig.3.

Then the vertical stay 27 supporting the bearings of the shaft in common to the above mentioned gears 9a and 9b is fastened to the cross bar 26.

With reference thereto, it has to be noted, both in fig.3 and in fig.4, that such stay 27, in the plan view, is in a substantially intermediate position between the front post 24a and the rear one 24b, such to allow the drive chains 7a and 7b to be aligned as described above.

As regards the vertical plane, on the contrary, the sleeves 23a and 23b and the end portion of the stay 27 are substantially arranged at the same height, such to allow the chains 7a and 7b to optimally operate.

Obviously several modifications to the cycling vehicle described above are possible, all falling within the knowledge of the person skilled in the art in light of the considerations shown up to this point.

An example is shown in the cycling vehicle 10 of fig. 5 wherein the same reference numbers denote parts equal to those already described from a constructional or functional point of view, therefore they are not further described.

Even in this case the two pedalling positions 4a and 4b are offset from each other, thus resulting in that when riding the vehicle 10 the riders are not one behind the other, with the same advantages described above.

The embodiment of fig.5 on the contrary provides the front wheel 3a and the rear wheel 3b to be aligned, as for a conventional bicycle, while the pedalling positions are offset from each other, one on the right of the frame 20 and the other one on the left, supported by suitable posts and linkages.

Obviously the pedalling positions may be at the same distance from the wheels 3 a, 3b otherwise, as shown, may be at different distances.

In this case the riders have a substantially comparable weight in order to balance the vehicle 10, such to prevent moments from throwing it off balance; as an alternative or in combination it is possible to provide to add one or more stabilizer wheels at the rear wheel, that, by resting on the ground, help in keeping the vehicle 10 stable when riding at low speeds.

In this solution the front handlebar 22a acts on the steering wheel by a link 31, for example a steel cable or chain.

Pinions 8a and 8b of each pair of cranksets 6a and 6b mesh with respective drive chains 7a and

7b that transmit the motion to the gears 90a and 90b fitted on the same shaft, to which even the gear 90c is associated which by means of the chain 7c meshes with the gears of the gearing assembly 90d, in order to transmit the motion to the rear drive wheel 3b.

An advantage in common to the two solutions of fig.l and 5 is that the two riders can use different pedalling ratios, such to match the effort to their characteristics or physical force.

In this case instead of a simple pinion 8a, 8b it is possible to provide two, three or more pinions having different dimensions, upon which the chains 7a and 7b are displaced (in a manner known in se) in order to achieve different gear ratios.

Still another variant of the cycling vehicle, denoted by the reference 100, is shown in the annexed fig.6.

Even in this case the same reference numbers denote the same parts of the two examples described above, and therefore they are no further described.

Suffice it to note that, in this case, the vehicle 100 is provided with two rear wheels 3b' and 3b", each one aligned with a corresponding pedalling position 4a and 4b.

The latter are offset from each other, such that when riding the two riders are not one behind the other, with the same advantages described above. In this case each pair of pedals 6a, 6b is connected to the respective rear wheel 3b' and 3b" by a dedicated chain 7a, 7b and gears.

It has to be noted that the two handlebars 22a and 22b in this case are both of the steering type, they being connected with the front wheel 3a by suitable links 31 and 3 , for example steel cables or chains.

Here the frame 200 follows a "T" shape, but it may be likewise made as a "Y", or the like. Then other variants, not shown, are further possible, for example comprising three, four or more pedalling positions arranged offset from each other, in combination with two, three or more wheels.

Again, instead of the bicycle chains it would be possible to likewise provide a driving toothed belt or the like.