Patent Application
20160272276
The present invention concerns a device that is equipped in newly assembled bicycles or other pedal-powered vehicles and can be coupled to current existing vehicles by means of retrofitting, enabling these to be placed in motion by operating one or two pedals or one or two handles without requiring too much effort, balance and/or strength from the user.
On the contrary, the bicycle is equipped with a mechanism that is easily activated and does not require special skills.
It can be used by any person and is particularly useful for people with physical disabilities, since the leg or arm movement that triggers the mechanism is done vertically, in other words, the movement is down, up, down, up, etc.
There already exist several devices that place in motion the gears fitted in bicycles or other pedal-powered vehicles by means of cranks, usually triggered by pedals.
However, there is no device like the one invented, since it enables to solve several technical issues such as those mentioned next.
Firstly, it enables to solve the neutral shift issue that bicycles with a traditional crank movement have (i.e., a circular movement).
In fact, to place a traditional bicycle in motion, the cranks cannot be aligned in the vertical position.
So, whenever there are two cranks, something which is not mandatory in this invention, they are never aligned in the vertical position, avoiding the neutral issue.
In this invention, the cranks (o r crank) only make a small arc of a circle and not a 360° turn.
This way, the user's movement in a vehicle equipped with the invented device (which we will designate as cyclist for convenience) is made with his feet, or foot, in a repetitive down, up, down, up movement, requiring only downward pressure in the pedals (or pedal), since the upward movement of each pedal is ensured by a spring.
Concern was shown in developing a device in which the cyclist could perform, with one foot or one hand, a simple repetitive movement and not the usual circular movement.
Likewise, for convenience, any pedal-powered vehicle will be designated from this point on as bicycle.
Another goal of the present invention is the use of two cranks or a single crank with a length greater than the standard one and that, despite this fact, never touches the front wheel of the bicycle.
The fact that the crank is considerably larger than the standard one and does not touch the front wheel is vital from a safety perspective, particularly when the cyclist attempts to curve.
In fact, in the present invention, each crank is limited to a small rotation lower than 90° .
For this reason, the crankshaft can be much closer to the bicycle's front wheel than usual, enabling the crank to have a significantly larger shaft than those used in standard devices.
Also, the further back the cyclist's position, the larger the crank can be.
In the case of a tricycle, the cyclist is usually seated above the wheels' rear shaft, since this position is further back than in bicycles.
In a tricycle of this kind, the crank will have a larger length and can be triggered by means of a handle.
The larger the crank's shaft, the lesser the strength required from the cyclist.
It must be added that, in general, in the so-called handbikes, the drive wheel is the front one, meaning that the weight of the cyclist is substantially shifted to that wheel.
This is inconvenient, particularly in slippery pavements where the front wheel may remain spinning uncontrollably, with no traction.
This inconvenience is solved with the current invention, since the drive wheel (or wheels) are located in the rear, where the weight of the cyclist is shifted.
Besides this, the invented device can also be stopped in a way that leaves the crank or cranks motionless so the cyclist may rest comfortably, with his feet on the pedals, while the bicycle maintains the built-up speed.
Also, the crankshaft is in front of the chain's sprockets (chainring), in other words, as previously mentioned, that shaft is closer to the bicycle's front wheel. As such, it is vital that the invented device enables a convenient ratio of speeds and, thus, integrate a gearbox that solves the added weight issue from the sprockets being directly activated by the crankshaft, a structure that is not equipped in standard bicycles.
It is necessary to take into account that the device has particular interest to people with physical disabilities, namely leg amputees who need to change gears, particularly in tight places, and perform climbs with ease and comfort.
The device is also intended to be compact and remain sealed with a cover, in order to avoid the cyclist from hurting himself in the gears and protect them from dust and other dirt that deteriorates them.
These and other technical aspects with several advantages are described below in detail.
This invention concerns a device that is equipped in bicycles or other traditional pedal-powered vehicles, fitted with at least one crank.
Since this crank concerns the right foot, its movement is limited to a small rotation lower than 90° that only occurs counterclockwise from 12 to 6 or clockwise from 6 to 12.
Regarding the left crank, the corresponding movement can only take place clockwise from 12 to 6 or counterclockwise from 6 to 12.
Each crank displays a box at its rearmost end, fitted with a unidirectional bearing box. Since the device is characterized in that each crank is fitted with a pedal or handle on the other end.
The concerned unidirectional bearing enables the movement that the user performs when pressing the pedal down (a near vertical movement) to be transmitted to the crankshaft, but when the pedal makes the opposite movement—downwards to upwards—by means of a torsion spring, this movement is not transmitted to the shaft.
It is also characterized in that the mentioned crank box is fitted with a flute, the box being contiguous to a fixed structure fitted with a pin, the crank movement being limited by the pin's movement within the flute, the box nestling a torsion spring at its lower end, one of the torsion springs being attached to this box and the other end to the fixed structure, the device being fitted with a braking mechanism for the crankshaft's sprockets and in that these are attached to the sprockets of the transmission box, which moves the crankshaft of the chainring.
The term flute relates to the traditional sense of the word, that is to say, referring to a groove, rail or guide.
The braking or locking/unlocking mechanism of the sprockets of the crankshaft must be triggered by a cable controlled through a handle installed in the bicycle's handle-bar.
In the unlocking position, the cable compresses the spring against a block. Since the spring is connected to a wedge, it remains in an upper position that keeps it away from the sprockets, not interfering with their movement.
When the spring stretches—something that takes place whenever the handle is used to relieve the cable—the wedge, which can have a mark to serve as a guide to its pin, will descend, making the pin go down until it locks into the sprockets, which will prevent them from moving.
This braking mechanism can be abridged to just the wedge with the guide and the cable.
Whenever the cable is relieved, the wedge will descend through gravity, blocking the sprockets of the crankshaft.
This braking mechanism is characterized either in that is fitted with a wedge with a guide that is activated by a spring with a block controlled by a cable or in that it is simply fitted with a wedge with a guide activated by a cable.
The invented device is also characterized in that has a dual-shaft transmission box (one inside of the other), an outer shaft with a slot, an inner shaft at least partially toothed, an unattached latch integrated in the previous shaft, a latch that latches, in turn, into the sprockets of the transmission box, which is the motor shaft of the chainring, and in that the toothed inner shaft is attached to a toothed shaft that makes it move when it is spinning.
As soon as the toothed shaft is triggered, spinning around its axis, its teeth, attached in the teeth of the inner shaft of the transmission box, making this shaft and also the latch integrated in it to shift crosswise.
On the other hand, the latch, during its crosswise movement, will go through the slot of the outer shaft of the transmission box and, in turn, latches to the sprockets of this box. The sprockets will, preferably, be fitted with one or more gaps where the top of the latch fits into.
This way, the movement of a given sprocket of the transmission box is transmitted to the latch, pushing its front side against the outer shaft of the transmission box.
This way, it will gain speed with the movement of that sprocket.
The invented device is also characterized in that the toothed shaft is housed in a box, in that this box is fitted with an outer lid (with an inner lid being also a possibility), in that the box is also fitted with both a middle lid and an upper one, where the middle lid is fitted with a torsion spring and is attached to one of its ends, with the other end attached to the top of the toothed shaft.
When the upper lid of the toothed shaft's box spins by the action of a cable, which can be triggered through a handle located in the bicycle's handlebar, the top of th e toothed shaft will spin, also transmitting the movement of the inner toothed shaft of the transmission box.
Whenever this cable is pulled, the toothed shaft spins around its axis, spinning the spring around itself and leaving it under tension.
When the cable is relieved, the spring automatically losses tension and, while attached to the top of the shaft, forces it to spin in the opposite direction.
This way, depending whether the top of the toothed shaft spins clockwise or counterclockwise, the inner toothed shaft of the transmission box will move crosswise from one side to the other of the bicycle.
When triggering, as described, the inner toothed shaft, the latch (which is connected to this shaft) will engage, in turn, the sprockets of the transmission box.
Thus, the sprockets coupled to the crankshaft will spin the several sprockets of the transmission box, permanently engaging them in pairs (one at the front and another at the back). The latch, by engaging, in turn, one single sprocket of the transmission box, transfers the movement of that sprocket to the outer shaft of said transmission box.
On the other hand, the sprockets coupled to the crank, as well as the braking mechanism, are protected by a cover.
As a result of what is mentioned above, the invented device is simple and the cyclist, by exerting a descending force perpendicular to the ground in a single pedal enables the vehicle to move with ease.
This invention can be built by using materials with a good weight/resistance ratio and a size that minimizes the space occupied.
In the attached figures, shown as an example, it is possible to observe the mentioned invented device and its parts as follows:
In particular, these figures represent:
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In further detail, the previous figures show one of the possible features of the invention, where the invented device is fitted with a braking mechanism (30) that prevents the movement of the cranks (3).
In fact, when the cable (31) of the mechanism relieves the helical spring (35), the wedge (32) descends, latching to the teeth of one of the sprockets of the crankshaft (24), preventing the movement of this shaft (20) and, therefore, also the cranks (3);
On the contrary, when the cable (31) compresses the spring (35) it contracts and makes an ascending movement, carrying the wedge (32) to which it is connected, a connection that can be achieved through the wedge's top (33), as shown in the figures.
The cable (31) that activates the braking mechanism must be triggered through a handle located in the handlebar.
Whenever this braking mechanism (30) is not activated, when the cyclist places the cranks (3) in motion by applying force in the pedals (2), or handles, will make the box of each crank (4) spin and apply tension to the torsion spring (13), being that this spinning movement is limited by the pin (15) that goes through the flute (5) present in every box.
The movement of the crank (3) is precisely limited by the movement that the pin (15) can perform from one end of the flute (5) to the other.
As soon as the cyclist applies force in the crank, through an up-down movement of the leg, the box (4) of that crank spins until it cannot move anymore, in other words, until the pin (15) leans to the other top of the flute (5), moving the crank to its lowest position closest to the ground, and once the movement that applied tension to th e torsion spring (13) is made, this will return the crank to its initial position, forcing the crank to perform the return down-up movement.
The torsion spring (13) is nestled in the lower end of the crank box (4), attaching one of its ends to this box and the other end to the fixed structure (14) contiguous to said box (4).
As for the transmission box (40), which is also part of the invention and aims to solve the issue concerning the added weight from the sprockets (24) activated directly by the crankshaft, its operation and conception can be made as detailed below.
The cable that triggers the transmission box (42) spins the upper lid of the toothed shaft's box (64).
This movement is transmitted to the toothed shaft (60), through its top (61), which is riveted in order to lock one of the ends of the torsion spring (62).
Depending whether the toothed shaft (60) spins or not, around its longitudinal axis, to one side or the other, leaving this spring (62) under tension or relieved.
Through the action of the cable/spring pair (42/62) this shaft (60) spins and is engaged to a toothed shaft (43)—the lower toothed shaft of the transmission box—moving crosswise, in other words, perpendicular to the alignment of the bicycle's wheels.
This inner toothed shaft (43) integrates a latch (55) with a spring (56), being possible for said shaft (43) to be fitted with a niche (44).
This latch (55), as soon as it latches to a single sprocket, each time, of the transmission box (41)—which spins fast while connected to the sprockets of the crankshaft (24)—makes the sprocket that is engaged to transmit the spinning movement.
The latch (55), in turn, with the front side (57), transmits this spinning movement to the outer shaft of the transmission box (50)—where the sprockets spin in the transmission box (41)—in whose slot (51) the latch is located.
The outer shaft (50), in turn, operates as the motor shaft of the chainring (23).
The latch (55) will have, preferably, a top beveled crosswise, since it is in this direction that the inner toothed shaft (43) controls it.
The sprockets of the transmission box (41) spin fast and the latch (55)—controlled by the inner toothed shaft (43) and in keeping with its crosswise movement—each time it finds a recess (45) of one of the sprockets, nestles in it by action of the respective spring (56), by transmitting the movement of the sprocket where it latched to the outer shaft of the transmission box (50) which is the motor shaft of the chainring (23).
| Number | Date | Country | Kind |
|---|---|---|---|
| 107242 | Oct 2013 | PT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2014/065486 | 10/20/2014 | WO | 00 |
