The invention relates to a pedal boat drive according to the generic clause of claim 1. It further relates to a pedal boat equipped with a pedal boat drive of the aforementioned type.
A pedal boat drive having the features of the generic clause of claim 1 is known from U.S. Pat. No. 6,165,029 as is a pedal boat equipped with such a drive. Although the prior art pedal boat permits storage of energy transmitted to the transmission train in a flywheel, it is not suited for a sports-related, flexible application.
Pedal boats are water borne vessels which have been known for a long time, serving primarily for pleasure. The pedal boats are in this context equipped with pedal boat drives, which by means of one or a plurality of pedal crank(s) transmit energy to a propulsion means, normally one or a plurality of propeller(s) or paddle wheel(s). The transfer of the drive energy takes place directly, i.e. the power is transferred to the propulsion means by the pedal crank(s) by way of a transmission means, e.g. a chain drive and/or a cardan shaft. In this way, in particular advancing and reversing of the pedal boat is controlled by the direction of rotation of the pedal cranks.
Examples of such pedal boats are known from the German utility model specifications DE 298 20 184 U1, DE 81 17 770 U1 and DE 84 04 297 U1.
In addition, a pedal boat comprising a drive means is known from DE 101 37 662 A1, wherein, in support of the propulsion means, an energy storage means, fed by the pedal drive, is provided in the transmission train, from which drive energy may be withdrawn, if so required, in order to bring about propulsion with reduced use of force. However, in this case as well the drive continues to be a direct one, the driving direction being determined by the direction of rotation of the pedal crank.
It is the object of the invention to so further develop a pedal boat drive that it enables a pedal boat to be used as an item of sports equipment. The pedal boat should in this context behave in water similarly to a bicycle on land with regard to the feeling of riding.
In order to attain this object, a pedal boat drive is proposed comprising the features of claim 1. Moreover, a pedal boat is proposed comprising the features of claim 7.
Due to the fact that a flywheel is mounted on a free-running axle in the transmission train, pedaling, with pedal cranks standing still, may be interrupted during a pedal boat ride, similarly to bicycle riding, without the pedal boat stopping immediately. The energy stored in the flywheel continues to propel the downstream portion of the transmission train and, in particular, the propulsion means, the boat continues to ride. The pedals are standing still in the course thereof; due to the free-running axle the portion of the transmission train preceding the flywheel is not driven by the energy stored therein.
A switching mechanism mounted in the transmission train for reversing the running direction of the propulsion means while the direction of rotation of the pedal cranks remains unchanged, permits simple and sporty maneuvering. In this manner, in particular the direction of propulsion of the propulsion means, for example a propeller, may be changed within the shortest possible time while pedaling of the pedal cranks continues. This, in contrast to known pedal boats, helps to considerably shorten the length of the brake path of a pedal boat equipped with such a drive by way of “thrust reversal”, which is an essential property for fast pedal boats, used for sports purposes.
A switching mechanism of the aforesaid type is readily realized if, according to the invention, two flywheels are mounted parallel to one another, while leaving an intermediate space therebetween and if in the intermediate space a take-off element, e.g. a rubber-sheathed roller, is provided, optionally adapted to be coupled to the inner faces of the flywheels facing one another. Depending on which of the inner faces the take-off element engages, its direction of rotation and, consequently, also the direction of propulsion, changes while the direction of rotation of the flywheel and, as a result, of the pedal crank, remains unchanged. It goes without saying that instead of two flywheels mounted parallel to one another, a single flywheel may be provided, comprising a radial slot in which the take-off element is mounted. Apart from the two positions of the switching element coupled to one of the inner faces, it may take up yet another, third position, in which it engages none of the inner faces. This position is then a neutral or idling position.
The switching mechanism may advantageously be actuated by one or a plurality of pneumatic actuator(s), but other actuating mechanisms such as, for example, cable controls, are likewise conceivable. In the case of a rubber-sheathed roller serving as the take-off element, the said roller may e.g. be connected to a downstream cardan shaft in order to drive the propulsion means and be shifted into the respective switching position by two pneumatic actuators positioned diametrically opposite one another.
The pneumatic actuators may be mounted in a closed pneumatic system together with an adjusting lever for activating the said pneumatic actuators. Thus, no pressure storage needs be provided; by simply actuating the adjusting lever the pressure required at any given time is generated and applied to the actuator to be activated.
The selection of a free-running axle comprising a flywheel also permits the mounting of a dual-ratio or multiple ratio transmission gear mechanism, preferably in the axle, in the fashion of a hub gear drive mechanism known from bicycle technology. In this way, the pedal boat equipped with a drive according to the invention may be used as an item of sports equipment in a plurality of gears, like a bicycle.
In order to adjust the driving properties of the pedal boat, approximating them, for example, to those of a bicycle on land, the mass of the flywheel(s) is selected accordingly. In this case, a total mass of the flywheel(s) of 50 to 100 kg, in particular 60 to 80 kg, is preferred.
For a sporty and maneuverable ride with the pedal boat, a boat comprising a twin hull (along the lines of a catamaran) is preferred in a pedal boat equipped with a drive according to the invention.
Finally, the pedal boat may be provided with a means for accommodating a conventional bicycle and integration of the latter into the transmission train. For this purpose, a roller may, for example, use the propulsion energy produced by the bicycle on its rear wheel and then transmit it to the flywheel in the further progression of the transmission train.
Further advantages and characteristics of the invention are apparent from the description which follows by way of the accompanying figures. There is shown in:
a and 2b the portion of the pedal boat drive comprising the flywheel as well as the take-off element and the on-following transmission train up to the propeller in two schematic side elevations,
The figures are schematic illustrations and are neither complete nor according to scale. In the figures identical parts are denoted by identical reference numerals.
The portion of the transmission train close to the propeller may be seen better in
a and 2b show two schematic side elevations of this portion. Apart from the already described elements, further elements of the pedal boat drive 10 according to the invention are shown there. Thus, 22 denotes the free-running axle, on which the double flywheel 16 is mounted. In addition, pneumatic actuators 24 connected via pneumatic ducts 23 to the adjusting lever 21 (not shown) may be seen. These engage the cardan shaft 19 connected to the rubber-sheathed roller 18, in order to be able to adjust the said cardan shaft and, consequently, the roller 18 in the intermediate space 17. For this purpose an articulation 25 is provided in the cardan shaft 19 so that the propeller 20 does not change its orientation when the cardan shaft 19 is adjusted.
Moreover, a transmission gear mechanism as well as a transmission control means 27 may be seen in
The above described switching mechanism can be better seen in
Of course, appropriate hydraulic elements may be provided instead of the pneumatic actuators 24 and pneumatic ducts 23.
The pedal boat drive according to the invention provides, for the first time, the possibility to use a pedal boat not only as an item of leisure equipment, but as a true item of sports equipment, similar to a bicycle, for example a mountain bike.
Number | Date | Country | Kind |
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03011291.6 | May 2003 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP04/05143 | 5/13/2004 | WO | 11/3/2005 |