Device for transportation on water

The invention relates to a device for transporting a person on water. More specifically the invention relates to a device consisting of two separate units attachable to each of a users legs being arranged to support the user such that he may transport himself on water by his own effort.

BACKGROUND OF THE INVENTION

Today there exist several popular water sports, such as e.g. wave surfing, wind surfing, sailing, water skiing, jet-skiing etc. In most of these water sports specific conditions are required to allow the user to perform them in the intended manner. Wave surfing requires relatively large waves of a certain shape that only appears at certain places at certain times and wind surfing and sailing requires favourable wind conditions. In other sports such as water skiing and jet-skiing the user is on the other hand dependent of a motor and can not transport himself on water neither by his own effort nor by the forces of nature.

There are however few devices that may be used regardless of external conditions.

PRIOR ART

US 6 848 958 discloses a device for transportation on water which is furnished with a floating carrier body from which two pivo table rods extend downwards into the water. The user fixes his feet to the ends of these rods and transports himself forward by pedalling his legs, wherein a fin on one of the rods takes the user forward and slightly downwards when the user moves the other rod downwards.

US 4 952 184 disclose a pair of skis for transportation on water. The skis have sufficiently buoyancy to carry the user and the lower surfaces of the skis are provided with fins, which are arranged to provide a small resistance upon transportation forward and a large resistance upon transportation backwards.

Consequently, a user may move forward by moving one ski at the time forward, the other ski preventing the user from gliding backwards.

US 6 468 118 discloses a personal watercraft including at least one stepper. Each stepper is pivotally associated with a propulsion member that is moveable in a generally vertical direction so that the propulsion member is in a first position during downward motion of the stepper and a second position during upward motion of the stepper. The device further includes a floating object, in which the user is placed.

All these devices include or depend on floating members. Additionally, none of these devices functions satisfactory and none of them provides the possibility of transportation at a substantial speed offering an "adventurous" feeling to the user. Thus, there exists a need of a water sports device that may be used regardless of weather conditions and without need of external features allowing a user to transport himself on water by own means and without floating members or further aid.

SUMMARY OF THE INVENTION

The object of the invention is thus to provide a device that allows a user to transport himself on water regardless of weather conditions and without floating members or further aid. This object is obtained by the device for transportation on water according to claim 1.

The invention relates to a device comprising two elongate separate units arranged to be worn essentially vertically on each of a users legs, each unit comprising an elongate body extending along essentially the whole length of the unit, each unit comprising: - a front side and a back side, an upper part with a fastening means for fixing a foot with the toes facing forward, the upper part being arranged to be to above water level, a lower part, on which at least one carrying element is arranged, the lower part being arranged to be below water level in use, and - a central part connecting the upper part with the lower part, the central part being arranged to be partly above water level and partly below

water level in use. The carrying element extends at a substantially right angle sideways from respective unit the carrying element having a front part at which they are pivotally connected to an elongate body and a rear part extending backwards with respect to the elongate body, the carrying elements being pivotable between an upper position, at which the carrying elements are essentially horizontal providing buoyancy to the user such that his weight partly takes him forward, and a lower position, at which the carrying elements may be placed essentially vertical with the rear parts pointing downwards, the lower position being approached automatically when a unit is driven upwards through the water. The fastening means includes an upper fastening means and a lower fastening means arranged to be fixed at different heights of the user's lower leg, such that the user may control the inclination of the unit with the inclination of his lower leg.

By means of the device according to the invention the user may transport himself forward on water without any floating members using his own weight. The user may gain height in the water by pedalling his feet and due to the configuration of the carrying elements the gained potential energy may then be converted into kinetic energy, taking the user forward and at the same time keeping him from sinking. The fastening means allows the user to control the inclination of the units with the inclination of his lower leg, such that they may be operated independently of each other.

Advantageous embodiments of the invention are presented in the dependent claims.

SHORT DESCRIPTION OF THE DRAWINGS

By way of examples preferred embodiments of the invention will be described below with reference to the accompanying drawings, in which:

Figure 1 shows a preferred embodiment of the device according to the invention mounted on a users leg;

Figure 2 shows the device of figure 1 partly in see-through lines;

Figure 3 shows the lower part of a unit of the device in figure 1 , the carrying elements being in a carrying position;

Figure 4 shows the same part as figure 3, when the carrying elements are in a free position;

Figure 5 shows a linkage between a foot plate and a carrying element;

Figure 6 shows the lowest part of a second embodiment of a unit according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following, preferred embodiments of the device according to the invention will be described. Firstly, with reference to figure 1 and 2, main details of the device and their functions will be described.

In figure 1 it is shown how a user 1 uses the device according to the invention to transport himself on water. The device 1 comprises two elongate separate units 101, 201 arranged to be worn in pairs essentially vertically on each of the users leg. Details of the unit 101, which is to be worn on the users right leg, have consistently been given reference numerals from 100, and correspondingly details on the other unit 201 have consistently been given reference numerals from 200. Each unit 101, 201 comprises an elongate body 102, 202 extending along essentially the length of the unit. The elongate body 102, 202 have a front side 103, 203 and a back side 104, 204. An upper part 105, 205 of the elongate body 102, 202 is arranged to be above water level in use and is furnished with fastening means 106, 206 for fixing the users 1 feet with the toes facing forward. A lower part 107, 207, which is arranged to be to below water level in use is furnished with at least one carrying element 108, 208. A central part 109, 209 connects the upper part 105, 205 with the lower part 107, 207.

In order to obtain as much buoyancy as possible the carrying element 108, 208 of the device preferably extend essentially orthogonally sideways from each unit 101, 201. They may also be arranged at an angle that is not orthogonal with respect to the unit 101, 201. It may for instance be

advantageous to arrange the carrying elements at an angle slightly upwards in order to decrease the magnitude of the lateral forces they cause. The carrying elements 108, 208 have a front part 108a, 208a at which they are pivotally connected to the elongate body 101, 102 and a rear part 108b, 208b extending backwards from the elongate body, the carrying elements 108, 208 being pivotable between an upper position and a lower position. In figures 1 and 2, the carrying elements 208 of the left unit 201 are in the upper position in which the carrying elements 208 are essentially horizontal, slanting slightly forward and providing buoyancy to the user so that his weight partly brings him forward. The carrying elements 108 of the left unit 101 are almost at the lower position in figure 1. The lower position is such that it allows the carrying elements to be placed essentially vertically with the rear parts 108b, 208b pointing downwards. The lower position is automatically approached when a unit is pulled upwards through the water.

Consequently, the user 1 may transport himself on the water by lifting one leg at a time, which allows him to gain height and potential energy with one leg at a time. The thus gained potential energy may then, due to the configuration of the carrying elements, be converted into kinetic energy forward.

The central part 109, 209 has a certain length L and is arranged to split the water line in use. The length L is preferably chosen to allow the user to glide a sufficient distance before additional potential energy has to be gained by lifting the legs, preferably one at a time. If sufficient potential energy has been obtained for both units 101, 201 at the same time, i.e. if both units are placed such that a major part of the length L of the central part 109, 209 is above water level, the user will be able to glide forward for quite a distance before additional potential energy has to be gained. Normally, however, the user glades on one unit at a time while he at the same time brings the other unit upwards.

In the following the components of the preferred embodiment will be described in closer detail. In figures 3 and 4 the details of the left unit 201 that are positioned below water level 2 in use are shown. In figure 3 the carrying elements 208 are positioned in the upper position, which are taken when the user's left foot rests on the fastening means 206 of the unit and an essential

part of the user's weight presses the unit 201 down. The weight is counterbalanced by the carrying elements 208, preventing the unit from sinking straight downwards. Instead the potential energy residing in the elevated position of the user's weight is at least partly converted to forward acting kinetic energy. The inclination of the carrying elements 208, i.e. the difference in height between the front part and the rear part, is partly decisive. If the carrying elements are completely horizontal the braking force produced by the carrying elements on the unit will alternately move the unit forward and backwards, wherein no real useful transportation is achieved. If, on the other hand, they are essentially vertical, with the front part 208a pointing downwards, the transportation will be consistent, but the useful transportation will be so small that the user will not get far before sinking.

Thus, the inclination of the carrying elements 208 should be chosen with care such that maximum transportation may be achieved, however an inclination of less than 2% is very difficult to handle. Once a certain velocity has been obtained it is possible to move the units forward without hardly any inclination at all of the carrying elements. In comparison, the superior surface of airplane wings even inclines slightly downwards towards the rear part. Preferably the inclination is different depending on the application of the device. In devices intended for novices the angle is preferably around 10 % and similar inclination magnitudes are appropriate for "playful" devices where the main object is something else than a maximum transportation in a minimum amount of time. As will be described closer in detail below, it may be possible to control the inclination of the carrying elements, both before and during use.

The quantity, the size and the shape of the carrying elements 108, 208 are other important parameters that may be controlled in order to obtain as much buoyancy as possible. The quantity and the size are of course related as they together define the total carrying area. What might be considered as a suitable carrying area partly depends on the users weight, as more weight requires more carrying force. In an extreme version of the device each unit may be provided with one single carrying element, which extends several meters to the side like a sailplane wing. However, such a configuration is both difficult to manoeuvre and inflexible, and only suited for transportation over large waters, free from obstacles.

Preferably and in order to achieve simple manoeuvring, several carrying elements are arranged, each extending approximately half a meter away from the body 102, 202. These carrying elements may instead be relatively wide from the front part to the rear part. For best performance the configuration of the carrying elements are individually adapted for a specific application and for a specific user in dependance of his weight and experience.

Of course, the positioning of the carrying elements is an important factor. The units 101, 201 according to the preferred embodiment are solely provided with carrying elements 108, 208 on the outsides, the insides being flat. This configuration is advantageous as the carrying elements of the separate units are prevented from mutual interference. However, it is of course possible to arrange the carrying elements in many different ways. For instance both sides of the elongate body 102, 202 may be provided with carrying element, and/or the elongate body may be parted into two or more vertical parts with carrying elements arranged between the parts.

Figure 4 shows the lower part 207 of a left unit 201 at a time when it is being pulled upwards through the water, wherein the position of each carrying element 208 is close to the lower position. The function of the lower position is merely to prevent the carrying elements from being rotated backwards, and during correct use the lower position is never reached. The carrying elements 208 are automatically turned to the position shown in figure 5 when the unit 201 is pulled upwards as the water above the elements 208 affects the rear parts 208b of them. In order to facilitate the pulling up of the unit 201 one might arrange a spring device acting downwards on the carrying elements. However, a spring is more preferably arranged such that the spring force acts in the opposite direction, thereby facilitating the action of bringing the carrying elements into the carrying position, i.e. the upper position (se fig. 5).

Another fashion of decreasing the resistance encountered by the carrying elements 208 on the way up and facilitating the pulling up of the units is to divide the carrying elements in smaller consecutive segments. However, such a configuration may substantially impede the buoyancy of the elements.

It is possible to arrange the carrying elements such that they may be rotated backwards. However, it is absolutely necessary for the well function of the

invention that the carrying elements are impeded from rotating forward in order to transform the weight of the user into kinetic energy in a forward direction. If they would be totally free to rotate forward they would assume the position that implies the least resistance when they are being pressed down by the weight of the user, wheras the rear part of the carrying elements would be pointing upwards and no forward acting kinetic energy would be gained.

From figures 1 and 2 the configuration of the fastening means 106, 206 of the units is apparent. Preferably, each fastening means 106, 206 comprises an upper fastening means including a securing strap 110, 210 arranged to be fixed around the user's lower leg. The securing straps 110, 210 are connected to a lower fastening means via a stiff joint 102a, 202a. The lower fastening means includes a foot plate 111, 211 which might be an integrated part of the elongate body 102, 202, the foot plate being arranged to carry the users feet. The foot plate 111, 211 is arranged essentially orthogonally with respect to the elongate body 102, 202 and comprises a front part 11 Ia, 21 Ia extending forward with respect to the elongate body 102, 202 and a back part 11 Ib, 21 Ib extending backwards. The lower fastening means further includes a front fastening means 112a, 212a and a rear fastening means 112b, 212b, which are both arranged on the foot plate 111 , 211 for the fixing of the users to the foot plate. Preferably, the user's foot is arranged on the outer side of the elongate body 102, 202, which is the case in the preferred embodiment. However, it is feasible to arrange the foot on the inner side or between the parts of a two-part elongate body.

The most important feature of the fastening means is of course to make sure that the feet and legs of the user are securely fastened to the separate units 101 resp. 201. The stiff joint 102a, 202a connecting the upper and the lower fastening means is useful as it allows the user to fix his lower leg at two different points at different heights, i.e. just under the knee and at the foot, respectively, allowing him to control the inclination of the unit. Due to the two different fastening points at different heights of the lower leg the unit becomes bound up with the lower part of the leg such that the unit 101, 201 and the lower leg will stay related to each other in essentially the same angle throughout the entire use. Additionally, the front fastening means 112a, 212a makes sure that the unit stays fixed to the foot when the user pulls his foot

upwards and the rear fastening means 112b, 212b fixes the heel part of the user's foot, whereas the foot plate 111, 211 of course constitutes an unpassable rest for the foot when the body weight rests upon it.

Figure 5 shows a part of an alternative embodiment of a unit according to the invention, in which a fixed link 213 connects the foot plate 211 to the carrying elements 208. The foot plate 211 is pivo tally arranged on the elongate body 202, wherein any rotation of the foot plate 211 affects a gliding element 214 gliding in an annular track 215 in the elongate body 202, the gliding element 214 being pressed downwards when the foot plate 211 is rotated forwardly. Further, the gliding element 214 is connected to another gliding element 215, via the fixed link 213, wherein each carrying element 208 has a gliding element 215 at its connection to the body 202. The gliding element 215 of the carrying elements 208 are also arranged in annular tracks 216 and are coupled to a blocking means 217, respectively. The blocking means 217 are arranged to limit the movability of the carrying elements 208. The limitation is achieved by a rotation block 218 fixedly connected the carrying elements, wherein the rotation block 218 is prevented from turning pass the blocking means 217, and wherein the limiting upper position is defined as the position where the rotation block 218 encounters the blocking means 217 from above, and the lower position is defined as the position where the rotation block 218 encounters the blocking means 217 from below.

Thus, it is possible for the user to control the inclination angle of the carrying elements 108, 208 during use, which is especially advantageous when he wants to put one foot in front of the other, wherein the units 101, 201 will have different angles of incidence into the water. In order to avoid that the units 101, 201 acts in different directions the inclination of the foot plates 111, 211 may be controlled so that the inclination of the carrying elements 108, 208 with respect to water level is the same for both units. This is achieved by arranging the footplates 111, 211 to equal inclinations with respect to the water level.

In the embodiment shown in figure 5 a spring 219 is arranged between the elongate body 202 and the rotation block 218 of the carrying elements 208. The spring 219 affects the carrying element 208, via the rotation block 218,

such that it takes less effort to move the carrying element 208 into the carrying (upper) position.

In a more simple embodiment of the invention the inclination of the foot plates 111, 211 and the carrying elements 108, 208 are instead individually adjustable. However, such an adjustment is not done during use, but before use. In yet a different embodiment the foot plate 111, 211 may be pivo tally connected to the elongate body 102, 202, but without connection to the carrying elements 108, 208.

In figure 5 the preferred shape of the carrying elements 108, 208 is apparent. Namely, the carrying elements are preferably wing shaped with a rounded front part 108a, 208a and a narrowing rear part 108b, 208b ending in an acute angle, the superior surface of the carrying elements is convex along its whole length, or almost its whole length. The degree of convextivity decreases towards the tip of the rear part, and the carrying elements 108, 208 might even be slightly concave near the tip. The lower surface of the carrying elements is convex at the part closest to the rounded front part, but is concave along a major part of its length towards the rear part 108b, 208b. At the back tip it may be more or less plane or even slightly convex.

In figure 6 an embodiment of the lower region of a unit,s lower part is shown. The lowermost part of the lower part is in this embodiment comprised of a slanted fin 220, which affects the lower part of the unit 201 such that it is forced inwards when the unit is moved downwards through the water. The fin 220 may either be fixedly or movably arranged such that it is folded back when the unit 201 is pulled upwards through the water. The fin 220 is intended to compensate for the lateral forces created as a result of that the carrying elements are arranged on only one side of the elongate body 202. These lateral forces may also be compensated for through adjustments of the angle at which the carrying elements 208 extend sideways from the elongate body.

A support 221 is arranged at the lowest part of the unit 201. The support 221 may be a rubber detail or any other suitable detail for protecting the unit if it should hit solid ground.

The preferred embodiments are intended to exemplify advantageous ways of configuring the device according to the invention. However, it is possible to configure the device in many different ways without parting from the spirit of the invention. The device according to the invention is thus only limited by the scope of the independent claim below.