AN ARM PROPULSION SYSTEM FOR BICYCLES AND SIMILAR, THAT MAY BE COMBINED WITH THE CONVENTIONAL FOOT PROPULSION

Abstract: An arm propulsion system for bicycles, that may be combined with the conventional foot propulsion, includes a sprocket wheel (5), that is coaxial with the pin (6) that connects the cranks (12), rotates in idle gear around said pin (6) and has on one side a radially toothed surface that gets engaged with one of two identical toothed surfaces present on the sides of a connection element (7) that is linked to the same rotation of the pin (6), making the sprocket wheel (5) linked or unlinked to the cranks' pin (6) according to the motion of said pin or of the sole said connection element (7).

Description: "AN ARM PROPULSION SYSTEM FOR BYCICLES AND SIMILAR, THAT MAY BE COMBINED WITH THE CONVENTIONAL FOOT PROPULSION" The present invention concerns an arm propulsion system for bycicles, that may be combined with the conventional foot propulsion, consisting of two cranks fixed at the end of a connection and rotation pin in a specular position to each other, whereby at the free ends thereof the relative grasping cranks are connected, liying and rotating on one and the same axis, parallel to the one connecting the cranks which are in turn connected, by means of a sprocket wheel and a chain or a small shaft or a belt or similar, to the front wheel. It is known that the greatest limitation in the use of the conventional bycicles consists in the activation of the sole muscles of the legs, while the arms provide for the direction, stabilization and braking of the bycicle, without performing any pulling force. For solving above mentioned disadvantage, the prior art lists many systems for applying motion to bycicles, comprising the combination of the action of legs and pelvis or even of legs and arms- All mentioned systems determine however a scarce balance for the user and/or a reduced manoeuvrability and/or make use of very complicate, expensive and too heavy mechanisms. In U.S. patent No. 632.797 granted on 12th September 1899 to G. VAN HORN, a bycicle is described with a handle-bar having the form of cranks and used for realizing a pulling force with the arms with a connection with the back wheel. This rotating handle-bar rotates a toothed wheel which in turn is connected, by means of a very long chain, to another sprocket wheel provided nearby the conventional sprocket wheel operated by the pedals. The disadvantage of said patent consists in that the extremely long, continuous chain - from the handle-bar to the pedal-hub, is twisted in the moment in which the handle-bar is turned for directing the bycicle. Many years later, this problem has been faced in Canadian patent no. 606713 of Ernesto Nacar who, starting from the bycicle of G. VAN HORN, has tried to prevent the twisting of the chain that connects to rotating handle-bar to the pinion of the pedals that move the rear wheel, thus obtaining a considerable series of gears connected to transmission shafts and chains, that seemed to allow the adhesion of the chain even when the handle-bar was turned. Said mechanism is very complex and presumably very heavy. The application of the pulling force, with direct connection to the front wheel instead to the back wheel, is shown in Italian patent application no. 48237 A/86 in the name of Roberto MEZZINI, in which a fork made integral with the central tube that usually supports the handle-bar, directed with the prongs upwards and provided, at the upper end, with a pedal keyboard placed in such a way as to be operated by the hands of the cyclist and that is connected, by means of a chain, to the hub of the front wheel provided with a pinion. The bycicle is provided with counter-pedal brakes inserted in the hub. This kind of bycicle makes use of a movement equal to the one produced by the legs by applying the same kind of pedals near the handlel-bar. The evident disadvantage of said means is the lack of stability and the difficulty in directing the bycicle, as the arms are to be hold in positions never specular to each other, as it occurs witha conventional handle-bar. The same inventor has tried to solve this problem in his own, further patent application no. RM 95 A 000 608 of 12th September 1995 in which, together with the pedal- keyboard, a second, fix handle-bar and a second saddle are provided, mounted near the fix handle¬ bar, and onto which the cyclist should rest his brest for finding a better balance while driving a double-traction bycicle. Further essays of creating a double-traction bycicle, by the use of levers or lever systems, have been performed, e.g., by Antonio GOMEZ ZARCO in his Spanish patent application no. 523432 of 21st June 1983, and by Horst EIFLER in his German patent no. DT 243677A1. Said bycicle means want to create an auxiliary traction onto the back wheel, making use of the arms of the cyclists which pull levers or the same handle-bar. The result shows a considerable lack of stability of the means and very complicate mechanisms. The arm propulsion system according to the present invention, on the contrary, has prooved to be totally stable, of easy conduction, manoeuvrability and safeness. The system described hereinbelow concerns the application of the transmission of motion to the front wheel of any kind of cycle, also in replacement and/or support of already existing structures, obtaining a completely independent traction system, operated by the muscle force of the arms and that may be used in combination or in alternative to the conventional one. According to the present invention, the arm propulsion system that may be combined with the conventional foot propulsion, without the inconveniences described of the other system with mixed propulsion, comprises a crank system placed near the conventional handle-bar; as the pair of cranks are connected to the handle-bar support, it follows the handle-bar each time the direction of the bycicle is varied. Thus, the cyclist uses the fix handle-bar in a conventinal manner only for changing direction or braking. In alternative, if he grasps the cranks he may use the front traction performing a synchronous circular and parallel movement with the arms and hands that is perfectly balanced, and in the same time he may intervene on the direction of the means. Infact, during the motion the cyclist may easily control and direct the bycicle as the forces exerced by the arms and hands onto the cranks are always the same, and therefore do not cause oscillations or lateral forces onto the front fork. Furthermore, laterally moving the stillstanding or rotating cranks as if they were the handle-bar, the front wheel may be perfectly directed and thus the whole cycling means. In a possible variant according to the present invention, the system provides the elimination of the conventional, fix handle-bar: in this case, the function of the fix handle-bar is obtained applying a mechanism that allows the eventual blocking to the rotating movement of the cranks which, once blocked but still connected to the handle-bar support, become a perfect handle-bar. Or, if they get not blocked, they are free to rotate and therefore to transmit motion, even if continuing to direct the bycicle. Once said cranks are blocked, the inconvenience may consist in that during the reverse motion - e.g. for moving the bycicle - the front wheel of the bycicle transmits the movement, by means of the chain, to the sprocket wheel integral with the pin connecting the cranks; if the latter are blocked, they prevent the reverse revolution of said front wheel and the bycicle must be pulled backwards. It is the aim of the system according to the present invention to solve all above mentioned inconveniences, and for this purpose a prefered and perfectly working variant thereof provides: - a particular system for blocking the cranks that allows, once operated, that the primary sprocket wheel remains free to rotate on its pin and therefor does not transmit the movement of the front wheel to said cranks if the bycicle is to be moved in reverse motion; - a chain transmission system with reduction gear with a plurality of gears of different diameters, against the already described variant that provides any transmission system from the cranks to the front wheel, reaching three purposes: - a smaller front encumbrance; - a better look; - a greater safety in case of accidental crashed, as said system is coated in a protection housing of small dimensions, like a box; a system for blocking the hand-grips, independent from the crank block; - the assemblying of the brake levers in a conventional manner, wherein the cables are always kept in predetermined positions for preventing the twisting thereof, without hindering the rotation of the cranks. The system according to the present invention will be described more in detail hereinbelow and consists of: - two cranks mounted in specular way at the ends of a rotation pin that connects the same; - a fork support connected to the handle-bar connection, that allows the housing of the rotation pin of the cranks mounted on bearings, and of two sprocket wheels and of the chain connecting them, which are part of the reduction gear system; - a cylindric, "connection" element, coaxial and integral with the rotation pin that connects the cranks, wheren said element has, on both lateral surfaces, shapings in the form of a tooth or of a step or other, so as to be inserted on one side in identical, shaped surfaces provided on one side of the bigger sprocket wheel, and on the other side on identical shaped surfaces provided on an internal side of the fork support box; - a coaxial sprocket wheel, mounted on the pin for the rotation and connection between the two cranks in such a way as to be free for rotating, and being connected by means of a toothed chain or gear to a smaller sprocket wheel, both clothed in a container, called "box"; - a third sprocket wheel that is fixed by means of a central pin and in coaxial manner to the smaller sprocket wheel, that is in turn connected to the hub of the front wheel of the bycicle by means of a toothed chain or other transmission like, e.g., a belt or a small shaft etc.; - two hand-grips that allow to grasp the cranks, which may be free to rotate idle on their own axis, or which may be blocked against the cranks. It shall be underlined that the whole pin may be moved by means of a selecting mechanism towards the bigger sprocket wheel or towards the wall opposite to the bigger sprocket wheel of said box; in the first case it will get stuck in the lateral wall of the crown and thus allowing the traction by means of the cranks; vice versa, if the rotation pin is approached to the opposite wall, it will get stuck in the wall of the box that is fix, with the consequent blocking of said cranks. In an equivalent, functional variant, the pin for the rotation and the connection of the cranks does not laterally move; only the cylindric connection means moves. In that case, the cylindric connection element, coaxial to the pin of the cranks, has a central, shaped hole that slides along the pin of the cranks, rotating together with the same. When the connection element is laterally moved, by means of appropriate levers or similar, the connection element is linked to the bigger sprocket wheel, coaxial with the crank pin and therefore to said pin, or to the fix part of the structure, thus hindering the rotation of the cranks' pin. Once the cyclist has decided to use the front traction, he will move the connection element towards the sprocket wheel that will get stuck onto said connection element, and operating onto the hand-grips with a circular and parallel synchronous movement arms-hands, the forwad motion of the pin will be obtained that will move the toothed crown which in turn will transmit the motion to the front wheel of the bycicle. The optimal combination of said reduction gear provides the use of a sprocket wheel coaxial to the cranks' pin, comprising thirty teeth and conneted, by means of a chain of the kind of an eight-pitch, with a nine-teeth sprocket wheel. On axis, and pin-connected to said nine-teeth, a seventeen-teeth sprocket wheel is provided, and by a conventional chain is connected to the change gear of the front wheel of the bycicle. During the motion, the cyclist may control and direct the bycicle, because the force exerted by the cyclist onto the cranks is always equal and do therefore not cause oscillations or lateral forces onto the front fork; furthermore, moving the still or moving cranks forwards, also the front wheel is rotated, giving the bycicle any desired direction. Said crank-mechanism therefore works like a real handle-bar onto which the brake levers are mounted. When the cyclist wants to use the sole feet motion-traction, in particular in some cases as in the urban traffic, he may wish that the cranks are perfectly still, or that the cranks and also the hand-grips are perfectly still in any angular position. For this purpose the selecting mechanism will move the connection element towards the rigid wall of the box, thus blocking the cranks, and then it will block the cranks by means of a system described hereinbelow. The blocking system for the hand-grips provides for the coupling of two complementary surfaces like teeth or steps or other, one on the end of each crank and the other on the bottom of the hand-grip's cylinder. When the hand-grips are approached to the centre of the bycicle, the surfaces get reciprocally engaged, hindering the relative rotation between hand-grips and cranks. When the hand-grips are moved towards the external sides, the surfaces are also removed, allowing the hand-grips to freely rotate around the cranks. The shaped surfaces allow to block the hand-grips in many angular positions around their own axis, so as to allow the cyclist a variety of choice for grasping the grips. A selecting system operated with a push-button hinders the accidental lateral movement of the hand-grips without the intention of the cyclist, assuring the free rotation or the blocking of the position of the hand-grips. When he uses both blocks (crank blocks/ hand-grip blocks), the cyclist will ride a completely conventional bycicle. The present invention will be described more in detail hereinbelow relating to the enclosed drawings in which a prefered embodiment is shown. Figure 1 shows a front view of a bycicle with the arm propulsion system, while figure 2 shows a lateral view of the upper-front part of the bycicle. Figures 3 and 4 show a section of the hand-grips 10 mounted onto appropriate cylinders 11 and shaped with teeth or radial reliefs, as shown in figure 5. A section of the hand-grip 10 with a detail of the selection mechanism 14 is shown in figure 6. In the described embodiment the case has been shown in which the sole pin of the cranks rotates and the connection element moves along the axis of the cranks' pin. The figures clearly show the two coaxial sprocket wheels 1, 2 which are connected, by means of two chains 3, 4, the first to the primary sprocket wheel 5, rotating in idle gear around the rotation pin 6 of said cranks, and the second to the change gear group fixed to the front wheel of the bycicle. In detail, figure 1 shows the connection element 7 rotating together with the pin 6 of the cranks and sliding on the same. Said connection element 7 has on its two sides the toothed surfaces that get alternatively engaged with two identical surfaces provided for respectively on the side of the primary sprocket wheel 5, coaxial with the pin 6 of the cranks, or on a fix part of the structure 8 supporting the cranks. A suitable selecting system 9 allows to move the connection element 7 onto pin 6 for engaging the same with one or the other toothed surface. Moving the crank 10 and the relative cylinder 11 so as to move the two toothed surfaces away from each other - as shown in figure 3 - the hand-grip 10 may rotate around crank 12 while, moving the hand-grip 10 in the opposite direction - as shown in figure 4 - the two shaped surfaces of the cylinder 11 and of the crank 12 are engaged, hindering the hand-grips 10 to move around the cranks 12. Said cranks 12 have two ring-shaped grooves 13, placed at a suitable distance, into which a selecting device 14 gets inserted, that has the function of keeping the cylinder 11 and the hand¬ grip 10 in the two furthermost positions of freedom or blocking. It is possible to provide for a series of gears, as an equivalent solution as an alternative to chain 3 and the relative sprocket wheels.

Claims: CLAIMS 1. An arm propulsion system for bycicles, that may be combined with the conventional foot propulsion, consisting of two cranks (12) fixed at the end of a connection and rotation pin (6) in a specular position to each other, whereby at the free ends thereof the relative hand-grips (10) are connected, liying and rotating on one and the same axis, parallel to the one connecting the cranks (12) and in turn connected, by means of a sprocket wheel (5) and a chain (3, 4) or a small shaft or a belt or similar, to the front wheel of the bycicle, characterized in that said sprocket wheel, that is coaxial with the pin (6) that connects the cranks (12), rotates in idle gear around said pin (6) and has on one side a radially toothed surface that gets engaged with one of two identical toothed surfaces present on the sides of a connection element (7) that is linked to the same rotation of the pin (6), making the sprocket wheel (5) linked or unlinked to the cranks' pin (6) according to the motion of said pin or of the sole said connection element (7) . 2. An arm propulsion system for bycicles according to claim 1, characterized in that the rigid structure, or box (8), that keeps the crank system is provided with a radial toothed surface (8) near said connection element (7) so that, leading said connection element (7) towards the rigid structure (8), in a direction opposite to the sprocket wheel (5) , the latter is made free to rotate around the cranks' pin (6), while said pin is made integral with the rigid fix structure (8) . 3. An arm propulsion system for bycicles according to claims 1 and 2, characterized in that it is provided with a reduction gear (1, 2, 3, 4) with a plurality of gears with different diameters, placed between sprocket wheel (5) coaxial with the connection pin (6) of the cranks and the change gear group of the bycicle's front wheel. 4. An arm propulsion system according to claims 1, 2 and 3 characterized in that the ends of the cranks (12) and the bottom of the internal cylinders (11) of the handlebar grips (10) each have a reciprocal toothed surface, and where a selecting mechanism (9) brings into contact the two surfaces of the cranks and of the internal cylinders (11) of the hand-grips (10) or moves them away, making the hand-grips (10) free to rotate around the cranks (12) or linked to the same. 5. An arm propulsion system for bycicles according to claims 1, 2, 3 and 4, characterized in that the brake levers are placeed on the cranks with the rotation fulcrum towards the support of the fork of the front wheel. 6. An arm propulsion system for bycicles according to claims 1, 2, 3, 4 and 5, characterized in that the sheathing of the brake cables are guided by the reduction gear box (8) so as not to hinder any movement of the cyclist. 7. An arm propulsion system for bycicles according to claim 1, characterized in that it consists of two handles (12) mounted in a specular position to each other, wherein at their ends the relative hand-grips (10) are connected, lying flanked on the same axis, and wherein the relative hand-grips (10) lie and rotate on the same axis, and wherein said specular cranks are united by means of a rotation pin (6) housed on an apposite seat provided onto a support (8) connected to the handle-bar connection, and wherein said two cranks are united to the rotation pin (6) in the same angular position, and wherin the movement of the cranks is transmitted to the front wheel of the bycicle by means of sprocket wheels (5, 2, 1) and a chain (3, 4) , or by means of pulleys and a belt or any other suitable mechanism. 8. An arm propulsion system for bycicles according to claim 1, consisting of two cranks (12) mounted in a specular position, where the relative hand-grips (10) are connected at their ends, said grips lying, flanked and parallel, on the same axis, characterized in that a mechanic device blocks the rotation of the cranks (12).

Inventors: RIGATO FABRIZIO, RIGATO, FABRIZIO
Applicants: RIGATO FABRIZIO, RIGATO, FABRIZIO
Application year: 1996
Main classification: B62M1
IPC codes: B62K19, B62M1, B62M3