Patent Application
20120299267
The present invention concerns a hand propelled vehicle.
More precisely, the invention concerns a vehicle the propulsion of which is controlled by the force of the arms.
Various kinds of vehicles that can be operated by the force of the arms have been hitherto developed, both for meeting an increasing market demand for non-polluting vehicles, and for meeting the needs of people suffering from handicaps at the lower limbs.
GB 2 379 640 discloses for instance a vehicle for paraplegic people, which has a double handlebar controlling the rotation of a pair of rear wheels through a transmission assembly comprising a rod-crank coupling.
U.S. Pat. No. 3,895,825 discloses a two-wheel vehicle in which a handlebar associated with an oscillating rod pivotally mounted on a tubular frame is provided. The oscillation of the rod causes the rotation of the rear wheel through a transmission assembly embodying a rod-crank mechanism and controls the steering of the front wheel through a connecting arm.
US 2006/0214387 discloses a hand-propelled three-wheel vehicle equipped with an oscillating handlebar associated with the vehicle frame through a vertical connecting arm transmitting the back-and-forth oscillatory motion of the handlebar to the rear wheels through a chain. The handlebar also controls the steering of the front wheel.
U.S. Pat. No. 4,925,200 discloses a hand-propelled three-wheel vehicle, with an oscillating handlebar transmitting the oscillatory motion to the rear wheels through a pair of chains and respective free wheel gears. The oscillating handlebar also controls the steering of the front wheel.
U.S. Pat. No. 5,713,590 discloses a four-wheel vehicle having a handlebar mounted on a oscillating rod, which controls both the steering of the front wheels, through a cable, and the rotation of the rear wheel, through a rod-crank transmission.
Patent Application IT-BS-2006000298 discloses a hand-propelled vehicle in which the movement is driven by the oscillatory motion of a rod, which is associated with the vehicle frame and has mounted thereon the handlebar to steer the front wheel.
The prior art solutions meet only partly the need, increasingly felt today, to have at disposal vehicles that are non-polluting, comfortable, safe, lightweight, handy and, above all, that can be operated with the least effort as possible, so that they can be used also by aged people.
Thus, it is a first object of the invention to provide a hand-propelled vehicle that demands a reduced operating effort, possibly lower than prior art vehicles, so that its use is easier.
It is another object of the invention to provide a vehicle that is robust and easy to manufacture and that demands less maintenance than prior art vehicles.
It is a further, but not the last object of the invention to provide a vehicle of the above kind, which can be produced at limited costs and is therefore suitable for large-scale industrial production, whereby diffusion of non-polluting means of transport is promoted.
The above and other objects are achieved by the hand-propelled vehicle as defined in the appended claims.
Advantageously, according to the invention, thanks to the use of a transmission assembly including a transmission shaft, perpendicular to the drive shaft and the driven shaft and kinematically connected to the drive shaft and the driven shaft through respective gears, the energy demand for driving the vehicle is reduced and it is possible to use gear ratios that do not excessively penalise the movement speed and therefore contribute to provide a smooth and continuous motion of the vehicle.
Still more advantageously, always according to the invention, thanks to the use of a pair of countershafts associated with respective free wheel devices, it is possible to fully take advantage of the back-and-forth oscillatory motion of the actuating rod and consequently to obtain a greater operation smoothness with a lower muscular effort.
Advantageously, always according to the invention, thanks to the arrangement of the transmission devices, it is possible to construct both vehicles for terrestrial use and vehicles for nautical use with limited costs.
Some embodiments of the transmission assembly according to the invention are disclosed hereinafter with reference to the accompanying Figures, in which:
In all Figures, the same reference numerals have been used to denote equal or functionally equivalent components.
Referring to
According to the invention, transmission assembly 19 includes at least one transmission shaft 25, perpendicular to drive shaft 21 and driven shaft 23 and kinematically connected to drive shaft 21 and driven shaft 23 through gears 27, 29.
According to the invention, each said gear 27, 29 comprises a respective toothed wheel 31, 33, fit on drive shaft 21 and driven shaft 23, respectively, and a respective sprocket wheel 36, 37, fit on transmission shaft 25.
Preferably, said gears 27, 29 are conical gears.
In a preferred embodiment of the invention, drive shaft 21, driven shaft 23 and transmission shaft 25 are associated with frame 13 through supports 30 equipped with bearings, for instance ball bearings.
According to the invention, propulsion controlling member 15 comprises an actuating bar 35 having a proximal end 35′ associated with frame 13 through a support 37 pivotally mounted on frame 13 so as to oscillate in a plane substantially orthogonal to drive shaft 21.
Actuating bar 35 also has a distal end 35″ associated with a handle 39 that, in the illustrated example, is made as a handlebar in order it is grasped, preferably with both hands, and is pushed downwards and pulled upwards in order to perform the reciprocating oscillatory motion.
Assembly 17 converting the reciprocating motion into circular motion includes a rod-crank mechanism with a rod 41 and a crank 43, capable of converting the reciprocating oscillatory motion of actuating bar 35 into a rotation of drive shaft 21.
Rod 41 has a small end 41′ connected to actuating bar 35, whereas crank 43 is fixedly connected to drive shaft 21.
In more detail, small end 41′ of rod 41 is pivotally connected to a sleeve joint 45 for connection to bar 35, which joint enables the bar to rotate about its axis even while oscillating, so as to control the vehicle steering, as it will be apparent from the following description of two applications of the transmission assembly.
Always according to the illustrated exemplary embodiment, crank 43 is defined in correspondence of a disc 47 fit onto drive shaft 21, from which a crank pin 43′ eccentrically extends. Rod 41 has a big end 41″ pivotally mounted on said crank pin 43′ of disc 47.
A seat 49 for the driver is associated with frame 13, preferably opposite propulsion controlling member 15.
Referring to
According to this variant embodiment, a flywheel 53 is kinematically connected through a belt 51 to the mechanism formed by rod 41 and crank 43. The flywheel comprises a disc-shaped body with suitable mass associated with a rotating shaft 55 arranged parallel to drive shaft 21 and mounted onto supports 57 equipped with bearings, for instance ball bearings, fastened to frame 13. Flywheel 53 is to make the propulsion motion of the vehicle smoother and more regular. More particular, the inertia accumulated by flywheel 53 enables attenuating motion discontinuity caused by the upper and lower dead points, which are encountered by actuating bar 35 during its oscillatory motion and at which inversion of the motion is requested of the vehicle driver.
Turning now to
According to the invention, each said gear 27a, 27b, 29a, 29b comprises a respective toothed wheel 31a, 31b, 33a, 33b fit on drive shaft 21 and driven shaft 23, respectively, and a respective sprocket wheel 36, 27, fit on transmission shaft 25a, 25b.
Preferably, said gears 27a, 27b, 29a, 29b are moreover conical gears.
According to this embodiment of the invention, transmission assemblies 19a, 19b are located on opposite sides of the mechanism formed by rod 41 and crank 43.
Moreover, a respective free wheel device 59 will be advantageously interposed between the mechanism formed by rod 41 and crank 43 and each transmission shaft 25a, 25b, preferably in correspondence of gears 27a, 27b.
According to this embodiment, the rotation of drive shaft 21 will be therefore limited to about 180° and will take place alternately in opposite directions.
Thanks to free wheel devices 59, the rotation of drive shaft 21 will be alternately transmitted to transmission shafts 25a, 25b, which will complete one revolution by 360° upon two consecutive downward or upward strokes of rod 41.
It is to be appreciated that the coupling of gears 27a, 27b, 29a, 29b is a conical coupling and that it is obtained internally of toothed wheels 31a, 31b, so that the reciprocating motion of crank 43 is converted into a continuous rotational motion, in the same direction, of driven shaft 23.
The transmission assembly disclosed in connection with such a second embodiment is particularly advantageous, in that surprisingly it results in a considerable reduction of the effort necessary for propelling the vehicle. Moreover, a vehicle equipped with such a transmission assembly is particularly comfortable and easy to drive and can be operated also by people who are not particularly robust.
Similarly to the first embodiment, also the vehicle structure described in connection with this second embodiment can be advantageously equipped with a flywheel of the kind described with reference to
Turning now to
Vehicle 101 has a front wheel 103 rotatably and pivotally mounted on a fork 105, and two parallel rear wheels 107, for instance with greater diameter than front wheel 103, which are fastened at the ends of driven shaft 23. Fork 105 is moreover rotatably associated with frame 13 and can be rotated through the rotation of bar 35 to which it is associated by means of an articulated joint 107.
A seat 49 for the vehicle driver is secured at the rear of frame 13, which is substantially trapezoidal.
Turning to
Vehicle 201 has a connecting bar 203 associated with actuating bar 35 in order to transmit the rotary motion of bar 35 to a rudder, not shown. Vehicle 201 is further equipped with a screw 205 driven by the rotation of driven shaft 23 through a transmission assembly comprising a pair of perpendicular shafts 207, 209, coupled through a gear 201 and receiving the motion from driven shaft 23 through a gear 213.
A seat 215 for the vehicle driver is provided, which seat is associated with a superstructure 217 secured centrally of frame 13 of structure 11 and arranged transversally across the vehicle. Vehicle 201 further has a hull 219 surrounding frame 13 and being, for instance, of the kind equipped with inflatable tubular elements 221.
Clearly, both vehicle 101 and vehicle 201 can embody vehicle structures made also in accordance with other embodiments, in particular the first embodiment disclosed with reference to
It is clear that the above description is given only by way of non-limiting example and that further changes and modifications are possible without departing from the scope of the invention as defined in the following claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB2010/000025 | 1/4/2010 | WO | 00 | 8/9/2012 |
