More specifically, the invention concerns a mechanical assembly of the above kind that, during the pedal stroke, allows to use at best all muscles moving the feet with respect to the body and to couple the motion of the foot with respect to the tibia, during its physiological extension, with the complete rotation of the foot-pedal, in order to optimise the results, both of the new pedal stroke, and of the rehabilitative therapy for the ankle articulation. As it is well known, during the years, search of solutions allowing to better exploit all the muscles of an athlete, or normal person, during the pedal stroke, has always more been intense, bringing to the realisation of different mechanisms.

A particularly interesting solution in this field is that subject of the Italian Patent NO 1,242, 156, filed by the same Applicant, Eng.

Cesare Albanese, on October 24,1990, and concerning an improved pedal-pedal crank assembly, wherein it is provided a technical solution allowing to mechanically exploit at best also the calfs and leg flexors muscles thrust, with very interesting advantages as far as the power is concerned.

Also of great interest are the studies toward the individuation of technical solutions allowing obtaining the maximum effect for the rehabilitation of the injured articulations, and that in the specific case involve, beyond the others, the ankle articulation.

Now, the Applicant has realised a new solution that, starting from what described in the preceding Italian patent, allows to obtain all the above mentioned results, and has a particular new advantageous application in the cyclette field, usually employed for training or for the rehabilitation of some articulations of the lower ends, including the ankle. Naturally, each cyclette will have a pair of new improved pedal-pedal crank assemblies.

In the following of the specification, it will be made reference to a"sector", by this term being meant every kind of element having the suitable shape and sizes for the specific case.

It is therefore specific object of the present invention an improved pedal-pedal crank assembly, particularly for a cyclette, comprising a pedal, a pedal crank, a frame, said assembly being characterised in that further comprises means to maintain fixed the orientation of the pedal-foot with respect to the frame during the rotation of the pedal crank, means for blocking the foot with the pedal, and a sector; said sector being integral with said specific means to maintain fixed the orientation of the pedal-foot during the rotation of the pedal crank.

Said sector can oscillate with respect to the frame, and means are provided for blocking the sector with respect to the frame and means to limit the amplitude of said oscillation.

Particularly, three different cases must be taken into consideration: 1) FREE SECTOR: in this case, the pedal stroke is carried out as in the case when the mechanism according to the invention is not employed, i. e. as in the standard bicycles ; 2) BLOCKED SECTOR: case when the new pedal stroke occurs with the orientation foot-shoe-foot in a fixed direction with respect to the frame and the angle between tibia and foot physiologically opens and closes during the 360° round of the pedal crank; 3) SECTOR HAVING A LIMITED OSCILLATION : angle from the oscillation of the sector constitutes the variation of the tibia-foot angle. In other words, employing means limiting the oscillation of said sector during the 360° rotation of the pedal crank, the sum of the angles described by the movement between tibia and foot and of the residual oscillation of the sector remains equal to the sector oscillation angle in case 1), that is equal to the angle described by the movement between tibia and foot in case 2). With the injuried ankle and the tibia-foot angle fixed, we are in case 1) and the maximum oscillation of the sector is maximum, almost equal to about 55°, while at the end of the therapy, with the sector blocked, we are in case 2) and the movement of the foot with respect to the tibia is maximum, i. e. equal to 55°, corresponding to the angle that at the beginning of the therapy was the sector oscillation angle.

Preferably, according to the invention, said sector is on the frame, and is coaxial to the axis of the pedal crank.

In a further embodiment of the assembly according to the invention, said sector can be placed distant from the rotation axis of the pedal crank, being always integral with said means allowing, with the blocked sector, to maintain fixed the orientation of the pedal during the rotation of the pedal crank.

Always according to the invention, said sector can be provided with a curved slot, slidable on a pin fixed on the frame, for blocking the same sector to said frame.

Furthermore, according to the invention, means for limiting the oscillation of the sector with respect to the frame can be comprised of two pins or bolts, movable along said curved slot, and provided with fixing means to the same sector, so that abutting against the above said pin a limited oscillation situation is obtained.

In a preferred embodiment of the pedal-pedal crank assembly according to the invention, said means for maintaining fixed the orientation of the pedal during the rotation of the pedal crank can comprise a first conical gear, coupled to the pedal, a shaft, provided substantially parallel with respect to, and inside, the pedal crank, and provided at its ends with conical gears, and a second conical gear, integral, directly, or indirectly, with said oscillating sector and lockable with said frame, said first and second conical gears being equal as well as equal are said conical gear provided at the ends of said shaft.

Further, according to the invention, pedal can be provided with fixing means for fixing and de-coupling said conical gear pair.

Still according to the invention, it is provided brake acting on the sector by an adjustable force and with a control in a convenient position for the physiotherapist.

Always according to the invention, said sector is provided with oscillating index, having a progressive oscillation, limited by the operator.

Furthermore, according to the invention, said conical gear pairs are different each other, the transmission ratio remaining the same.

The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments,

with particular reference to the figures of the enclosed drawings, wherein: Figure 1 is a section view of an embodiment of the assembly according to the invention; figure 2 is a front view of an assembly according to the invention, limited to the sector; figure 3 is an operation scheme of the assembly according to the invention, with free sector and tibia-foot angle of 90° ; figure 4 is an operation scheme of the assembly according to the invention, with sector blocked integral to the frame; and figures 5a and 5b show a graph relevant to the size of the angle between tibia and foot-pedal with respect to the angular position of the pedal crank. observing first figures 1 and 2 of the enclosed drawings, it is shown an embodiment of the assembly according to the invention, providing a specific mechanical solution allowing to maintain during the pedal stroke the pedal with a constant orientation with respect to the bicycle frame, but it is to be understood that, as it will be seen in greater detail in the following, the specific mechanical solution chosen is not essential for the invention, since it can be any solution according to the Italian patent N° 1,242, 156, that is herein incorporated by reference.

In any case describing the represented solution, it provides a pedal 1, a pedal crank 2 and a pedal crank 2 axis 3.

Between said pedal 1 and the frame 4 of the bicycle, it is provided a mechanism comprising a first conical gear 5, a shaft 6, with a double conical gear, parallel with respect to said pedal crank 2, and a second conical gear 7, integral with a sector 8, oscillating and lockable with respect to said frame 4.

Said mechanism comprised of two conical gears 5 and 7, and of the shaft 6 with double conical gear is another example of a solution according to said Italian patent NO 1,242, 156"that, as already said, is herein incorporated by reference.

Pedal 1 is provided with a system 9 allowing to disengage it from the conical gear 5, and that is useful to keep the pedal completely freely rotating about its pin 10, also with the pedal crank 2

stopped: in this way it works as the standard pedal, and obviously the pedal stroke is the same.

Observing now in greater detail figure 2, it can be understood the utility and the essential function of sector 8 for rehabilitation of the foot articulation.

Said sector is provided with a curved slot 10, delimiting the ends of the physiological oscillation of the foot with the pedal crank stopped. Said oscillation occurs about a pin 11, fixed to the frame, and provided with means, not shown in the figure, (a wing nut) allowing to block said sector 8 to the frame 4. Only with the sector partially or completely blocked, and the foot-shoe-pedal blocked all together to realise a single unit, we have the use of the solution according to the invention, and the new pedal stroke.

Always along the slot 10, two pins or bolts 12,13 are provided, laterally with respect to said pin 11, blockable in the movable sector, and allowing to limit the oscillation of the same sector 8.

The brake 14 is mounted on said frame 4, coupled with a standard means, indicated by the reference number 15.

When the sector 8 is blocked by the pin 11, thanks to the pin 11, either in case the pedal crank is stopped or it is rotating, pedal 1 cannot rotate, so that the foot of the patient, along with the shoe and the pedal, will maintain the fixed orientation with respect to the frame decided by the physiotherapist.

During the pedal stroke, if the oscillation of sector 8 is allowed, between the two ends of the slot 10, angle between foot and tibia can remain fixed, thus allowing at the beginning of the therapy, to pedal even if the patient is not able to vary the tibia-foot angle.

Physiotherapist, acting on the two pins 12 and 13, can progressively reduce the oscillation angle of the sector 8, until reaching, with the progressive healing of the patient, the blocking of the sector. Practically, bolts 12 and 13 are approached each other, until realising the blocking of sector 8 with pin 11.

Path of the projection of the ankle on the plane of the pedal passing through its axis with the sector not blocked on the frame 4 can be seen in figure 3. In this figure, it is shown the condition

wherein the angle between tibia and foot is voluntarily maintained by the patient, or it is maintained because the patient is immobilised.

In figure 4 it is instead shown the conference covered by the ankle with the sector blocked with respect to the frame 4.

Finally, in graph of figures 5a and 5b it is shown in the abscissa the angular position of the pedal crank and of the ankle along the same circumference covered by the same, when the sector 8 is blocked on the frame 4. Curve in ordinate represents the value of the angle between the direction of the pedal-shoe-foot assembly and the tibia with respect to, in abscissa, the angles of the circular motion of pedal crank.

When angle between tibia and pedal is voluntarily maintained fixed at 90°, see figures 5a and 5b, the rectilinear line parallel to the abscissa, passing through the 90° value of the ordinate represents it.

To use a cyclette with an assembly as the one proposed by the present invention, it will made the adjustment of the two different pedals 1: in fact, a ankle can be injuried and the other one not. In case the movable sector would not adequately coincide with frame, one acts manually until properly positioning said sector on the frame by the means 11. The same applies for the orientation of the foot-pedal by the means 9.

Pedal crank 2 can be in each position along the 360° arc, as well as the relevant pedal 1 : leaving blocked the pedal crank where it is, it is sufficient to free the pedal 1 from the conical gear 5 by a correct action on the cam 9, then rotating the pedal-shoe assembly in such a way that its direction is of 43, 5°, with the tip of the shoe directed downward. Rotating the pedal crank 2, pedal 1 maintains fixed its orientation with respect to the horizontal line of 43, 4° (see figure 4).

The solution according to the present invention, with the sector 8 blocked, also allows to obtain an optimum pumping of the venous blood toward the heart, carried out by the hardening and the sliding of the muscles of the calf during 55° of movement of the foot.

As already said, it can be particularly applied for the physical therapy of the ankle, allowing to progressively increase the mobility of the foot with respect to the tibia.

The solution can also be useful for old cyclists used to maintain fixed the tibia-foot angle, so that the articulation of the ankle is enough ankylose.

It is further possible to suppose a different embodiment.

Observing now figure 1, it can be hypotised to realise pedal crank 2 comprised of a solid metal bar, and not with a hollow metal bar, horseshoe shaped. Two sprockets, having the same number of shaped teeth, usually employed with a chain, and placing a suitably long chain between the two sprockets replace the two bigger conical gears.

A ring having an eccentrically and conical outer surface, having a threaded inner hole to receive the axis of the pedal, can be used as chain tightener, that, while it is tightened and fixed on the pedal crank, blocks the position of the same chain tightener.

Chain and the two sprockets, coplanar with respect to the surface orthogonal to the axis of the pedal cranks and of the pedals, imposing that said pedal crank is slightly S shaped.

By the solution according to the present invention it is allowed to the physiotherapist to independently examine and rehabilitate groups of muscles and articulations. For example, it is possible, blocking the gearing behind the, and by the, pedal cranks, to control the efficiency of the ankle articulation with the oscillation degrees of the sector, negative or positive with respect to the"zero" of the pin 11, obviously with the movement of the concerned foot of the patient.

If instead the sector is blocked, it can be evaluated the result on the rear wheel ; it can be evaluated the energy, eventually comparing it with that of the other foot.

Very interesting is the fact that with the sector blocked, and the pedal crank at the beginning blocked at 330° (figure 5a), and foot and pedal at 85° with respect to the horizontal, opening movement of the angle between tibia and foot of 45° induced by the patient involves, with a transmission ratio 1: 1, the rotation of the pedal crank and of the rear wheel of 150°. It is the first time that calf muscles on a cyclette, by the foot, transmit movement and power to a wheel.

Differently with respect to the standard pedal, the new improved pedal-pedal crank assembly involves the absolute blocking

of foot-shoe on the pedal in such a way that the three parts are, during the pedal stroke, an integral single piece. Means to realise the above are shown in the drawings.

For a cyclette, shoe must be such not to allow the exit of the foot when the latter is stretched upward, and must have means to be bolted to the pedal, or fixed, or by the physiatrist action.

It must be taken into consideration that in the new pedal stroke, all the points moving up to the acetabulum keeping the caput femuris, covering an absolutely pre-established trajectory: this does not occur in the standard pedal stroke.

The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.