TWO-WHEEL DRIVE BICYCLE WITH FRONT WHEEL

HYDRAULIC ASSIST

This invention relates to the manufacture of a two-wheel drive bicycle. This is achieved by the manufacture and use of suitable components for the generation of hydraulic power used to drive the front wheel.

The more general use of bike so far requires the driver to turn the pedal so that, by means of cogs and chains, it causes the rear wheel to rotate. In the more general motion of bicycle, the front wheel is involved simply by rolling, without being thrust or assisted in any other rotational motion. Thus the movement and speed of a bike, along with its rider, depends entirely on the time and frequency the rider turns the pedals, as well as the morphology of the terrain on which he/she rides. The disadvantages are that speed decreases gradually due to friction when the rider stops turning the pedals, unless moving downhill, and that the rider's energy when turning the pedals is consumed entirely for the rear wheel drive.

The present invention is intended to provide hydraulic thrust, by means of a suitable hydraulic fluid (oil), to the front wheel of the bicycle simultaneously and automatically with the rear wheel rotation. Thus when the rider turns the pedals, simultaneous rotational movement of both the rear wheel through the chain and the front wheel by the oil pressure generated by the rotating rear wheel is achieved.

According to the invention, the advantages are that the simultaneous drive of the front wheel results in better cycling behaviour in terms of possible slip at turns. Also, in bicycles used for climbing and descending in mountainous environment and due to rough terrain, better adhesion and generally better bicycle behaviour is achieved due to two-wheel drive. Due to the generated rotation of the front wheel while making the same effort by the rider to turn the pedals, the bike moves for more time at a steady speed, as when the rear wheel rotates, the front wheel is also rotated without the rider being obliged to turn the pedals continuously. Thus, the rider is required to re-pedal at a lower frequency than he would on a conventional bicycle not taking advantage of the present invention. Another advantage is that the transfer of oil as the means of hydraulic power produced to the front wheel is made by the use of small flexible pipes, thereby achieving its rotation, but at the same time allowing the driver to turn the front wheel when he wants to change direction and generally control the direction of the bike without any problems. In addition, this invention may also be applied to any type of bicycle by simply installing some of the components that make up the invention on the bicycle frame in combination with the replacement of some of the existing bicycle components with other modified components so that all working together give the desired result. In addition, a manual oil pressure relief valve can be fitted to the bike’s handlebars to allow the rider to reset the pressure of the oil rotating the front wheel to stop the invention operation. This can be useful when the bike is moving downhill on a steep slope in which the rider does not want extra thrust.

The components of the invention are small and light as they can be made of aluminium or carbon filaments and are designed, on the one hand, to withstand the mechanical stresses they suffer throughout their operation and, on the other hand, to perform so that they achieve the desired result.

The present invention can be fully understood from the following detailed description with respect to the accompanying drawings, in which:

Figure 1 shows a cross-section of the oil pump (1) with all its essential components. Thus, according to the invention, using oil generates the hydraulic power by means of the rotational motion of the rear wheel, which is conveyed by fine tubing to the front wheel, thereby achieving simultaneous rotation thereof.

Fig. 2 shows a perspective view of the rear wheel as well as a portion of the bicycle frame (14), showing the external components of the invention connected to the oil pump making up the essential component of Fig. 1. Fig. 3 shows a section of the impeller which being attached to the front wheel and receiving the pressurized oil, is rotated pushing the front wheel to a similar motion, too.

To facilitate the reader, identical reference numbers are used to identify common elements in the figures, where present.

According to Fig. 1, the structure (1) comprises an outer cylinder (2), on which the drive cogs (6) are permanently attached and rotate due to their connection to the pedals through the chain (7). Also on the periphery of the cylinder (2), the spokes (3) of the rear wheel are attached, which at their other end terminate perimetrically on the bicycle rim. Trapezoidal flaps (33) are located between the spokes (3) and perimetrically on the cylinder (2), which serve to cool the structure by means of the air while rotating the wheel. Inside the cylinder (2) there is a cylinder (14) which is firmly attached to the rear fixed fork members of the bicycle frame (8) by means of the nuts (11). Between the outer (2) and the inner cylinder (14) according to the figure, there are two ball bearings (31) which are used to easily rotate the cylinder (2) as the wheel rotates, while at the same time the cylinder (14) remains steady due to its attachment to the rear fixed fork members of the bicycle frame (8). The outer cylinder (2) has a fixed toothing (18) at the one end and in the internal perimeter.

According to the figure, the inner cylinder (14) consists of three parts. The left side cap-axle shaft (15), the main cylinder body (14) and the right cap- axle shaft (29). The three pieces are joined together using the screws (16) which are mounted on the front peripheral surface on the left and right caps of the inner cylinder (14) in such a way that their head is fully inserted into them. Thus, according to the figure, the front peripheral surface of the caps (15, 29) remains free and flat to accommodate the two ball bearings (31). On the rotating outer cylinder (2) and externally of the left side cap (15), the metal ring (4) is fitted using the screws (5) to further protect the left side cap (15) and to protect the left ball bearing (31). Inside the inner cylinder (14) according to the invention, an oil pump is located which provides the hydraulic pressure required to drive the front wheel. To prevent oil leakage from the structure in joining the three parts (15, 14, 29) of the inner cylinder, two elastic rings (16, 17) known as o-rings are mounted in specially designed grooves providing the necessary sealing. The gear type pump oil provides and maintains constant hydraulic pressure at low revs and consists of the two engaged cogs (21, 24). More specifically, the cog (24) rotates around the shaft (25), while the cog (21) rotates around the shaft (20). To facilitate connection and disconnection of the shaft (20) in the centre of the cog (21), key ways are constructed both internally in the centre of the cog (21) and at some point on the shaft (20) surface so that by using a respective wedge the two components can be connected together so that the shaft (20) rotation also entrains the movement of the cog (21). Immediately past the cog (21) along the shaft (20) according to the drawing, there is a socket built-in on the right cap (29) to mount the gasket (22) which protects the structure against oil leakage. Past the gasket (22), the ball bearing (23) is positioned for easy rotation of the shaft (20). To secure the ball bearing (23), a horseshoe inner safety (32) is used. Finally, according to fig. 1 of the invention, at the other end of the shaft (20), the cog (19) is also positioned by using a similar wedge, the cog (19) being secured in place by means of a safety nut in such a way that it comes into complete engagement with the inner toothing (18) of the outer cylinder (2). The oil pump cylinder structure according to Figure 1 of the invention is completed by the oil suction valve (26) and the oil depression control valve (27).

The invention according to Fig. 1 begins to operate when the wheel is rotated. Then, the outer cylinder (2) which is firmly attached to the cogs (6) begins to rotate by means of the ball bearings (31). In turn, the cog (19) is dragged into movement due to its internal perimeter toothing (18). The outer cog (19) rotates the shaft (20), the shaft rotates the inner cog (21) and the latter rotates the adjacent cog (24). Thus, the oil pump is turned on starting to suck the oil in the chamber (28) through the oil suction valve (26). The oil is continuously fed to the chamber (28) via the passage (30) of the left-hand cap-axle shaft (15) and the metal tube (10). After the oil pump, the oil exits under pressure through the oil depressing valve (27) and through the passage (34) of the right hand cap-axle shaft (29) comes out to the metal tube (9) which is firmly screwed to the thread (12) at the end of the right-hand cap-axle shaft (29), through the nut (13). This particular construction as shown in Fig. 1 enables the user to completely disassemble it for cleaning, maintenance or replacement of its internal components.

According to Fig. 2, an oil refilling container (11) continuously supplying with non- pressurized oil the chamber (28) through the metal tube (10) as also shown in Fig. 1 and a cylinder (4) being the oil pressure regulator (4), which maintains the pressure constant throughout the network, are located on the bicycle frame (12) and at a point higher than the rear wheel of the bicycle (13). As the oil exits under pressure from the oil pump as described in Fig. 1, passing through the tube (9) resting on the bicycle frame (8), it enters the cylinder (4) pushing the plunger (2) ) upwards. This in turn compresses the spring (5) raising the operating oil pressure of the invention. The plunger stops going upwards when the hole (3) from which the pressurized oil is returned to the oil filler container (11) is revealed. At the oil entry point in the cylinder (4), an analogue pressure gauge is located so that the rider is aware of the hydraulic operating pressure of the structure at all times. Finally, the rider may change the hydraulic operating pressure of the structure by simply screwing, when wanting to raise it, or by unscrewing, when wanting to lower it, the screw (7) into the thread (6). In this way, the spring (5) is compressed or decompressed, thus increasing or reducing the hydraulic pressure respectively. The oil under controlled pressure is led through the metal tube (19) to drive the front wheel, as described in figure 3.

According to Fig. 3, the structure (25) is the intersection of the transmission impeller on the front wheel of the bicycle using the pressurized oil. In particular, the front wheel (24) is positioned between the front fork tubes of the bicycle frame (21), supported by the shaft (22) secured by using the nut (23). Next to the wheel and inside the frame (21), there is the impeller structure consisting of the shells (1, 2) which are joined together by the use of screws (3). Internally and circumferentially at the point where the two shells (1, 2) are tangent, there are specially designed grooves in which an elastic ring (4) known as the o-ring is mounted for the necessary sealing. The shells (1, 2) are fixed to the shaft (22) by means of the fixed metal fitting (10) using the screws (11). The metal component (10) is securely attached to the shaft (22) via the screw (9) according to the drawing. The chamber created by the two shells (1, 2) and within which the impeller is located and rotated is completely sealed by both using the rubber ring (4) and the seals (12,15). Also the fixed flaps (5, 6) mounted on the outside of the shells (1,2) offer better air-cooling of the structure when cycling. The spokes of the front wheel (24) of the bicycle are attached to the central cylinder (17) on which the outer part of the impeller (16) is firmly joined by the screws (18), which passing through the shells (1, 2), creates the metal disc (7) on which the flaps (8) are mounted. The rotary impeller sealing (16, 7, 8) is achieved by using the gaskets (13, 15). Also, the ball bearing (14) is positioned between the shaft (22) and the impeller (16, 7, 8) for easy rotation of the latter.

Thus according to the drawing, the pressurized oil passes through the metal tube (19), then through the connecting nozzle (26) and enters the impeller sealed chamber (16,7,8) causing it to rotate as it strikes over on the flaps (8). The rotation of the impeller (16, 7, 8), insofar it is firmly attached to the wheel (24) as described above, helps in the wheel's rotating movement. The pressurized oil exits the impeller seal chamber (16, 7, 8) through the connecting nozzle (27) and passing through the metal tube (20), it returns to the oil filling container (11) as shown in Figure 2.

Thus, according to the construction, we achieve the adjustable hydraulic assist in rotating the front wheel. The material of manufacture of the aforementioned components of the three designs may be aluminium which provides resistance to mechanical stress during the operation of the components, but at the same time offers a low weight of manufacture.