WO2025078971A1

WO2025078971A1 - Muscular propulsion system and vehicle using said muscular propulsion system

Info

Publication number: WO2025078971A1
Application number: PCT/IB2024/059876
Authority: WO
Inventors: Giuseppe Calearo
Original assignee: Abness Benefit Srl Soc
Current assignee: Abness Benefit Srl Soc
Priority date: 2023-10-13
Filing date: 2024-10-09
Publication date: 2025-04-17
Anticipated expiration: 2026-04-13
Also published as: IT202300021393A1

Abstract

A muscle propulsion system (1), comprising: a pair of pedals (2) each associated with a pedal crank (3) keyed to a central shaft (4), a central hub (6) to which a mechanical torque transmission means (7) is keyed and a motion transmission group (8) that transfers to the central hub (6) the rotation that the pedals (2) impose on the pedal cranks (3). The motion transmission group (8) comprises a pair of free wheels (9', 9'') keyed to the central hub (6), a pair of return rods (11 ) keyed to the central shaft (4) and a pair of flexible elements (10) each of which has the initial section (10a) wound on a respective free wheel (9', 9'') and the final section (10c) associated with a respective return rod (11 ). Between the free wheels (9', 9'') there is interposed a toothed wheel (9a) that meshes with both free wheels (9', 9'').

Description

MUSCULAR PROPULSION SYSTEM AND VEHICLE USING SAID MUSCULAR PROPULSION SYSTEM

DESCRIPTION

The invention concerns a muscle propulsion system particularly but not exclusively suitable for the propulsion of vehicles and particularly of velocipedes, for example bicycles, tricycles and similar vehicles.

The propulsion system of the invention is also suitable to be applied to devices specially designed for fitness and well-being, or for post-traumatic rehabilitation of a person.

The invention also concerns a velocipede, preferably but not exclusively a bicycle, which uses the aforesaid propulsion system.

Finally, the propulsion system of the invention can be used to operate any mechanical device, for example any fluid pumping or product or object handling system or in any case any operating or driving machine.

The known muscle propulsion systems of velocipedes and similar devices comprise variously designed kinematics that usually use one or more chains kinematically connected to toothed wheels that transmit to a wheel the torque generated by pedals placed in rotation by the user.

However, all the aforesaid known muscle propulsion systems have the acknowledged limitation due to which they are usually able to transform into useful work performed only a small part of the work that the user is able to produce by acting on the pedals.

From experimental measurements carried out on velocipedes of known type, in particular on bicycles, it has been found that in the best cases the achievable efficiency is less than 50%.

It can be understood that this makes the aforesaid known muscle propulsion systems poorly performing.

Furthermore, it must be said that the velocipedes, for example bicycles, which are equipped with the aforesaid muscle propulsion systems, have some limitations and criticalities that directly derive from the fact that the generation of torque is entrusted precisely to the known kinematics comprising chain - toothed wheels - pedals.

As is known, in bicycles the positioning of the known kinematics comprising chain - toothed wheels - pedals entails that the user’s centre of gravity is positioned significantly high above the ground and this is to the detriment of safety as it makes it easier to overturn the bicycle.

In addition, the construction features in the known muscle propulsion systems comprising chain - toothed wheels - pedals, together with the significantly high position that the user assumes while riding, also entail a significant stress on the frame and the entire frame - wheels - handlebar system.

In addition to this, in some of the known muscle propulsion systems, the steering of the velocipede is entrusted to the handlebar which is free to rotate directly on the steering axis of the wheel, being able to make an angle much greater than that actually necessary to turn, and is exerted by the user who acts on the handlebar by rotating the front wheel to orient it in the steering direction.

It can be understood that this freedom of manoeuvre can cause accidents in the event of incorrect or accidental manoeuvres of the handlebar or while travelling on roads if the uneven bottom imposes abnormal rotations to the front wheel.

The present invention aims to overcome the limitations, criticalities and drawbacks that have been listed and that are found in the known muscle propulsion systems and in the velocipedes, in particular bicycles, which use them.

In particular, it is an object of the invention to realize a muscle propulsion system that allows the user, with the same work produced, to obtain a useful work greater than the one that can be developed with the muscle propulsion systems of known type that have been mentioned.

It is also an object of the invention to realize a velocipede, particularly a bicycle, which uses the aforesaid muscle propulsion system subject-matter of the invention itself.

It is also an object of the invention that the transmission ratio can be realized in continuous variation or in steps.

It is a further object that in the bicycle of the invention the front wheel is provided with a steering traction hub.

It is another object that in the bicycle of the invention the steering can be independent of the rotation of the handlebar and can be delegated to appropriate control members.

It is another object that in the bicycle of the invention the position of the user’s centre of gravity is significantly closer to the ground than in bicycles of the prior art.

Last but not least object is that the stresses acting on the bicycle of the invention, and especially on the frame during use, are significantly lower than those that can be found in the bicycles of known type.

The listed objects are achieved with the realization of the muscle propulsion system and of the velocipede, particularly a bicycle, both subject-matter of the invention, whose fundamental realization characteristics respond to what is described in the main claim and in the dependent claims to which reference will be made.

Advantageously, the muscle propulsion system of the invention achieves a higher efficiency than the known muscle propulsion systems and develops, compared to them, a higher useful work that can reach an approximately double value.

Still advantageously, the muscle propulsion system of the invention, although particularly suitable to be applied to velocipedes and particularly to bicycles, can also be used in other similar applications, or even belonging to different sectors.

Further advantageously, during the description of the bicycle of the invention it will be highlighted that the lowering of the user’s centre of gravity while riding, the better ergonomics and the lower stresses to which the bicycle is subjected while riding make the operation of the latter safer compared to the operation of bicycles of the prior art.

The purposes and advantages that have been listed will be better highlighted during the description of the muscle propulsion system and of the velocipede that uses it, preferably but not exclusively a bicycle, which is given below by way of indicative and non-limiting purposes only, with reference to the appended drawings in which:

- figure 1 represents an axonometric view of the muscle propulsion system of the invention;

- figure 2 represents a detail of figure 1 ;

- figure 3 represents a sectional view of the muscle propulsion system of the invention;

- figure 4 represents an enlarged detail of figure 3;

- figure 5 represents another axonometric view of the muscle propulsion system of the invention; - figures 6 and 7 represent two different enlarged views of a detail of figure 5;

- figure 8 represents the enlarged front section of the detail of figure 5 represented in the axonometric views of figures 6 and 7;

- figure 9 represents the side view of the bicycle of the invention using the muscle propulsion system of the invention represented in figures 1 to 8;

- figure 10 represents the front view of the bicycle of figure 9.

The muscle propulsion system of the invention is depicted as a whole in figures 1 and 5 where it is indicated overall with 1.

Details of the muscle propulsion system 1 of the invention are visible in detail figures 2, 4 and 6 to 8.

It can be observed in the aforesaid figures that the muscle propulsion system 1, which for the sake of simplicity we will indicate below with the term propulsion system 1, comprises a pair of pedals 2 each of which is associated with a first end 3a of a pedal crank 3, where this pedal crank 3 has the second end 3b keyed to a central shaft 4 rotatably associated with a frame 5 that supports it.

In the embodiment being described, the pedal crank 3 has a fixed length but in another embodiment which is not depicted in the drawings the pedal crank may be of variable length.

The frame 5 is also associated with a central hub 6 that identifies a longitudinal axis X of rotation of a possible mechanical torque transmission means, defined also as a wheel 7, adapted to be keyed coaxial to the aforesaid central hub 6.

In addition, a motion transmission group 8 rotates the central hub 6 around the longitudinal axis X since it transfers to the aforesaid central hub 6 the rotation that the pair of pedals 2 imposes on the pedal cranks 3.

It is pointed out that, in the present embodiment example of the invention, the wheel 7 is a bicycle wheel of known type, but it is not excluded that this wheel 7 is a generic mechanical torque transmission means, such as for example a toothed wheel or a universal joint to be considered also of known type.

According to the invention, the motion transmission group 8 visible as a whole in figures 3 and 4 comprises a pair of free wheels 9’, 9” keyed to the central hub 6 and visible in particular in figure 4, a pair of return rods 11 keyed to the central shaft 4 visible in figure 1 and a pair of flexible elements 10 with predominantly longitudinal development visible particularly in the detail of figure 2, each of which has the initial section 10a wound on a respective free wheel 9’, 9”, as can be observed in figure 4.

It can also be observed that the free wheels 9’, 9” are made dependent on each other by the toothed wheel 9a interposed between them, which can be observed in figure 4 and which preferably but not exclusively is a conical toothed wheel that meshes with both free wheels 9’, 9”.

In this way, when one of the flexible elements 10 is put under traction by the movement of the pedals 2 and is unwound from the respective free wheel, for example from the free wheel 9’, which is thus placed in rotation to transmit the torque to the central hub 6, at the same time the toothed wheel 9a puts in counter-rotation the other free wheel 9” obtaining the rewinding thereon of the respective flexible element 10 which had been previously put under traction by the movement of the pedals 2 and unwound from the free wheel 9” to transmit the torque to the central hub 6.

In addition, the intermediate section 10b of each flexible element 10 that constitutes the traction cable that alternately rotates the free wheels 9’, 9” is guided by a return group 12 supported by the frame 5, as can be observed in figure 2, while the final section 10c is associated with a respective return rod 11 , as can be observed in figures 1 and 5.

With regard to the return rod 11, it is adjustable in length to modify the transmission ratio continuously or in steps upon intervention of the operator who operates manually by acting on the adjustment group 13 that can be observed in figures 1 and 5.

Furthermore, in the figures it can also be observed that the return group 12 comprises idle pulleys 12a on which each flexible element 10 slides, which preferably but not exclusively is a metal cable.

Furthermore, observing in particular figure 9 in which the propulsion system 1 is applied to a bicycle as a whole indicated with 50 and about which it will be discussed below, it can be noted that the arrangement of the propulsion system 1 is such that the movement that the user sitting on the saddle 51 imparts to the pedal cranks 3 by acting on the pedals 2 is alternating and oscillating and develops according to an arc of circle A which subtends an angle of rotation not greater than 180°.

With regard to the central shaft 4, it can be observed in figures 5 to 7 and particularly in detail figure 8 that it is housed inside a tubular sleeve 30 which is fixed to the frame 5 and in which two annular bodies 31, 32 are also housed which are separated from each other by a spacer ring 33 and are connected to the central shaft 4 and to the respective pedal cranks 3.

In addition, there is a cap 36 with screw tightening 35 that axially constrains the annular bodies 31, 32, the spacer ring 33 and the central shaft 4 inside the tubular sleeve 30.

It can be observed that in each of the annular bodies 31 , 32 there is a shaped seat 31a, 32a that slidably accommodates a respective return rod 11 whose protrusion with respect to the central shaft 4 can therefore be varied by the user by intervening on the adjustment group 13.

It should be specified that the position of the returns as described is not binding as, for example, they could be supported directly on the pedal cranks by means of appropriate support and adjustment members of the prior art.

In addition, inside the tubular sleeve 30 there are bearings preferably of the rolling type 34 that are interposed between the annular bodies 31, 32 and the spacer ring 33 to facilitate mutual rotation during the movement of the pedals 2 that generate the oscillating motion of the pedal cranks 3.

As regards the central hub 6 and the free wheels 9, as can be observed particularly in the sectional detail view of figure 4, they are housed inside a sleeve 14 which is fixed to the frame 5 and particularly to the end of the fork 5a to which the wheel 7 is connected.

In the tube 14 there is also housed a central group 15 which is adapted to mechanically connect the wheel 7 to the central hub 6 and is configured to allow the rotation of the aforesaid wheel 7 around the longitudinal axis X when the motion transmission group 8 transfers to the central hub 6 the rotation that the pair of pedals 2 imparts to the pedal cranks 3.

In addition, as will be described in more detail below, the central group 15 also allows the rotation of the same wheel 7 around a transverse axis Y orthogonal to the longitudinal axis X when control means 26, which are visible in figures 1 , 5 and 9 and are supported by the frame 5, are operated by the user and impose a rotation on the central group 15 around the aforesaid transverse axis Y.

For this purpose it can be observed that the central group 15 comprises a central annular body 16 which is keyed coaxial between the central hub 6 and the wheel 7 and is axially comprised between a pair of lateral annular bodies 17a, 17b both keyed coaxial between the central hub 6 and the wheel 7. It should be specified that the rotation of the central hub 6 that performs the rotation of the wheel 7 associated with it around the longitudinal axis X can be claimed independently of the muscle propulsion system 1.

To favour the rotation of the central annular body 16 and of the lateral annular bodies 17a, 17b between them and with respect to the central hub 6 and to the tube 14, there are a first bearing 18, preferably but not exclusively a first row of spheres, which is interposed between the lateral annular bodies 17a, 17b and the tube 14, a second bearing 19, preferably but not exclusively a second row of spheres, which is interposed between each of the lateral annular bodies 17a, 17b and the central annular body 16, and a series of spheres 20 interposed between the internal annular surface 16a of the central annular body 16 and a curved seat 21 belonging to the central hub 6.

Furthermore, at least one of the lateral annular bodies is provided with a shaped rod 27 having a first coupling point 27a and a second coupling point 27b which can be particularly observed in figure 9 and which are spaced apart from each other and configured to be connected to the control means 26.

It can be particularly observed in figures 5 and 9 that control means 26 comprise a tie rod 23 which is supported by through elements 24 fixed to the frame 5 and which cooperates with a lever 25 that is rotatable according to an axis of rotation Z and associated with the frame 5.

In the event that the propulsion system 1 is applied to the bicycle 50 that can be observed in figure 9, the rotatable lever 25 will belong to the handlebar 52 or to another structural element of the bicycle to which it will be applied in a suitable position to perform the task of directing the velocipede in the direction desired by the user.

In particular, it can be observed in figures 5 and 9 that downstream of the through elements 24 the tie rod 23 is divided into a first section 23a whose end is connected to the first coupling point 27a of the shaped rod 27 and a second section 23b whose end is connected to the second coupling point 27b of the shaped rod itself.

It can also be observed that the rotatable lever 25 is included between the through elements 24 and therein there is a through hole 25a in which the tie rod 23 is received.

In this way, when the rotatable lever 25 is rotated it puts under tension the first section 23a or the second section 23b of the tie rod 23 depending on the direction in which the rotatable lever 25 is rotated and this generates the rotation of the shaped rod 27 and of the respective lateral annular body 17a or 17b around the transverse axis Y.

In addition, the rotation of the central group 15 and of the wheel 7 around the transverse axis Y is also obtained due to the presence in the central annular body 16 of the shaped protrusion 16b which is received in the shaped seat 21 obtained in the central hub 6.

In the propulsion system 1 there is also a braking group which is substantially a disc brake of known type 40 or any other system of known type associated with the wheel 7.

The invention also concerns a vehicle 50 which is represented in figures 9 and 10 and which comprises a frame 5 which supports a saddle 51, a handlebar 52, two or more wheels 7, and which uses the muscle propulsion system 1 that has been described herein for the transmission of torque and of power to at least one of the wheels 7.

Preferably but not exclusively, the vehicle 50 is a bicycle.

Operationally, the operation of the muscle propulsion system 1 of the invention is described with reference to the application form in which it is used as a propulsion system of a bicycle 50.

The user sits on the saddle 51, grasps the handlebar 52 with his/her hands, binds his/her feet to the pedals 2 and starts pedalling.

As mentioned, pedalling takes place with alternating and oscillating rotation of the pedal cranks 3 and therefore with a movement of the legs that are alternately stretched and retracted performing a movement that the propulsion system 1 of the invention, unlike bicycles of known type, develops according to a direction substantially tangent to the arc described by the pedal cranks.

This particular movement can allow the saddle 51 to be arranged in a position very close to the ground and this favours the displacement of the centre of gravity of the bicycle - user system into a significantly lower position than to what is possible in the bicycles of known type, reducing the possibility of overturning with respect to the latter and thus achieving one of the objects of the invention to obtain a safer bicycle.

Furthermore, the use of the propulsion system 1 of the invention and in particular the specific pedalling position and the position of the centre of gravity lower than known bicycles significantly reduce the stresses to which the frame 5 of the bicycle and overall the entire frame - wheels - handlebar system are subjected during use, thereby achieving another of the objects of the invention.

In an embodiment that is not depicted in the figures, the pedal cranks 3 may be provided with an extension that extends beyond the central shaft 4 and is grippable by the user, who with the force of the arms will be able to increase the torque that through the pedal cranks 3 is applied to the central hub 6 and therefore to the wheel 7.

In addition to this, it has been seen that in the bicycle of the invention the steering is not exerted by the handlebar, like in the bicycles of the prior art, but by special controls not bound to the movement itself and which limit its amplitude.

This allows to achieve the further object of the invention to reduce the accidents that occur in the bicycles of the prior art caused by incorrect or involuntary manoeuvres of the handlebar.

It has also been seen that the propulsion system of the invention employs flexible elements 10 associated with free wheels 9 and with return rods 11 connected to the central shaft 4 which is supported by bearing elements and this makes the transmission of rotation from the pedal cranks 3 to the central hub 6 of the wheel 7 quieter and safer, reducing the possibility of breakage and the need for maintenance compared to prior art propulsion systems employing the toothed wheel-chain system.

Furthermore, it has been seen from experimental tests on prototypes that the muscle propulsion system of the invention allows the user, with the same work produced, to obtain a performed work greater than the one obtainable with muscle propulsion systems of known type, thus achieving another of the objects of the invention.

From what has been said, it can therefore be affirmed that the muscle propulsion system 1 and the vehicle that uses it, for example a bicycle 50, both subject-matter of the invention, achieve all the objects that have been listed in the introductory part of the description.

As already mentioned, the muscle propulsion system 1 of the invention can be applied to any vehicle or can be used for the propulsion of systems of other type.

In the operational step, modifications and variants may be made to the invention that have not been represented, described or even represented in the attached drawings.

However, it is understood that, if these modifications and variants should fall within the scope of protection of the appended claims, they must certainly all be considered protected by this patent.

Claims

1 ) Muscle propulsion system (1 ), comprising:

- a pair of pedals

(2) each associated with a first end (3a) of a pedal crank

(3), said pedal crank (3) having a second end (3b) keyed to a central shaft

(4) rotatably associated with a frame (5);

- a central hub (6) associated with said frame (5) and identifying a longitudinal axis (X) of rotation for a means for transmission of the mechanical torque (7) adapted to be keyed coaxial outside said central hub (6);

- a motion transmission group (8) that transfers to said central hub (6) the rotation that said pair of pedals (2) imposes on said pedal cranks (3); characterized in that said motion transmission group (8) comprises a pair of free wheels (9’, 9”) keyed to said central hub (6), a pair of return rods (11 ) keyed to said central shaft (4) and a pair of flexible elements (10) with predominantly longitudinal development, each of which has the initial section (10a) wound on a respective one of said free wheels (9’, 9”) and the final section (10c) associated with a respective one of said return rods (11 ), between said free wheels (9’, 9”) there being interposed a toothed wheel (9a) that meshes with said free wheels (9’, 9”) and makes them dependent on each other by linking the alternation of the movement of the pedal cranks (3).

2) Muscle propulsion system (1 ) according to claim 1 , characterized in that each of said flexible elements (10) has the intermediate section (10b) guided by a return group (12) supported by said frame (5).

3) Muscle propulsion system (1 ) according to any one of the preceding claims, characterized in that the movement of said pedal cranks (3) is alternating and oscillating.

4) Muscle propulsion system (1 ) according to any one of the preceding claims, characterized in that said pedal cranks (3) are associated with said central shaft (4) which is housed inside a tubular sleeve (30) fixed to said frame (5) and in which there are also housed two annular bodies (31 , 32) which are separated from each other by a spacer ring (33) and are connected to said central shaft (4), in said tubular sleeve (30) there being also a cap (36) with screw tightening (35) which axially constrains said annular bodies (31 , 32), said spacer ring (33) and said central shaft (4) inside the tubular sleeve (30).

5) Muscle propulsion system (1 ) according to claim 4, characterized in that inside said tubular sleeve (30) there are bearings (34) interposed between said annular bodies (31 , 32) and said spacer ring (33).

6) Muscle propulsion system (1 ) according to any one of the preceding claims, characterized in that said central hub (6) and said free wheels (9) are housed inside a tube (14) which is fixed to said frame (5) and in which there is also housed a central group (15) adapted to mechanically connect said mechanical torque transmission means (7) to said central hub (6), and which is configured to allow the rotation of said mechanical torque transmission means (7):

- around said longitudinal axis (X) when said motion transmission group (8) transfers to said central hub (6) the rotation that said pair of pedals (2) imposes on said pedal cranks (3);

- around a transverse axis (Y) orthogonal to said longitudinal axis (X) when control means (26) operated by the user and supported by said frame (5) impose a rotation on said central group (15).

7) Muscle propulsion system (1 ) according to claim 6, characterized in that said central group (15) comprises:

- a central annular body (16) keyed coaxial to said central hub (6) and adapted to be keyed coaxially to said mechanical torque transmission means (7);

- a pair of lateral annular bodies (17a, 17b) both keyed coaxial to said central hub (6) and adapted to be keyed coaxial to said mechanical torque transmission means (7);

- a first bearing (18) interposed between each of said lateral annular bodies (17a, 17b) and said tube (14);

- a second bearing (19) interposed between each of said lateral annular bodies (17a, 17b) and said central annular body (16);

- a series of spheres (20) interposed between the inner annular surface (16a) of said central annular body (16) and a shaped seat (21 ) belonging to said central hub (6), at least one of said lateral annular bodies (17b) being provided with a shaped rod (27) having a first coupling point (27a) and a second coupling point (27b) spaced apart from each other which are configured to be connected to said control means (26).

8) Vehicle (50) comprising a frame (5) supporting a saddle (51 ), a handlebar (52), two or more wheels (7) and a muscle propulsion system (1 ) for the transmission of torque and power to at least one of said wheels (7), characterized in that said muscle propulsion system (1 ) is made according to any one of the preceding claims from 1 to 7, wherein said mechanical torque transmission means (7) is one of said wheels (7) keyed coaxial outside said central hub (6).

9) Vehicle (50) according to claim 8, characterized in that it is a bicycle.