The present invention relates to a device for propulsion, stabilisation and steering of a vessel, comprising an elongated first power transmission rod which is rotatable fastened to the vessel and which extends down into the surrounding water, where the first power transmission rod is arranged to be rotated and pivoted outwards about its anchorage point on the vessel, about both a vertical axis and a horizontal axis, an elongated, second power transmission rod connected to an upper end of the first power transmission rod, and at least two oar blades, arranged to a lower part of the first power transmission rod so that they can pivot outwards, where the oar blades are fastened to the lower part of the first power transmission rod, and that the side surfaces of the oar blades extend in a plane that corresponds to the longitudinal axis of said power transmission rod, and where each oar blade further comprises a fastening part that is arranged in the same longitudinal direction as the longitudinal axis of said power transmission rod.

From known technology FI 12960 C, for one, shall be pointed out. In this document, a rudder and propulsion system for boats is described, which at one end comprises a handle fastened to a rod that can revolve about the stern of a boat, and that the rod, at its other, outwardly swinging end, in the same plane as the handle, comprises a shaft with two oar blades which are connected to an elastic connecting unit. The rod is arranged in a vertical plane so that by movement of the handle in a horizontal plane the rod is rotated about a vertical axis. The shaft, which is fastened to the out-swinging end of the rod, is in the same plane as the handle, i. e. that the oar blades fastened to the shaft are also moved in a horizontal plane in the water. Because of the pressure of the water, the oar blades can revolve about the shaft, in that the connecting unit yields when they are moved in the water and the oar blades are moved back to their original position when the pressure from the water decreases.

US A 5,181, 872 describes a system that shall replace conventional oars or paddles, comprising a folding scoop and a handle. The device is not fastened to the boat, but is to be used in that the handle is led forwards and backwards by the person in the boat so that the scoop opens and closes in the water, as the scoop in its open position is thereby subjecting a pushing force onto the water and consequently also onto the boat.

Disadvantages with the known solutions are that the effect is relatively small. Both the systems describes function in that muscle power is transferred to a mechanical appliance, either to the handle whereupon this power is transferred to the oar blades, or to the scoop described in US A 5,181, 872. Because of the pressure and flow of water, much of the supplied force is lost when the force is to be transferred in the water as a pushing force.

Furthermore, a relatively large force is necessary to both open and close the oar blades or scoop referred to. This is also because of the water turbulence behind the edge of the oar blade. The turbulence creates an under-pressure behind the oar and will prevent a part of the movement.

A device for propulsion and steering of a vessel consisting of two arms joined together at one point is further known from US 2,979, 018. US 2,808, 802 and US 4,043, 292 also show corresponding appliances.

The present invention has as an aim to provide a solution for easier propulsion, steering and stabilisation of vessels. The device according to the present invention is arranged to set vessels in motion via the fanning movement in water of two or more vertically hinged blades.

The invention provides many advantages in relation to known solutions, among other things, the combi-oar is easy to operate as a rowing tool. It is of a simple construction that makes it both light and inexpensive to manufacture and also easy to repair. It has excellent steering properties and can therefore be used as a spare rudder.

Furthermore, the device according to the invention, can be scaled up from small boats to larger vessels, something that makes it especially applicable for all types of vessels. It is possible to row the vessel either forwards or backwards by a simple adjustment.

Two locked oars at the back of a vessel will give propulsion in sideways waves because of the influence of the sea on the oar blades. The device can function as a drift anchor that can be steered, which can prevent the vessel drifting towards land. A locked oar can contribute to dampen heaving movements of the vessel. Two or more oars can dampen both heaving and sideways movements.

Furthermore, the combi-oar, according to the invention, can in certain cases replace engine power when setting out and pulling in of equipment and ropes. It can replace trim flaps. Wear and tear of ropes when moored can be prevented in that the device contributes to keep the vessel steadier in the water.

According to the invention, the combi-oar can be adjusted so that it can be adapted to the body and fitness of everybody. Furthermore, it is possible to connect the oar to a mechanical operation.

The above mentioned objects are achieved with a device, according to the invention as defined in claim 1, and is characterised in that the lower part of the first power transmission rod comprises at least two longitudinal, opposite grooves, said grooves running in the longitudinal axis of said power transmission rod, arranged to receive the respective fastening parts of the oar blades, and that the fastening parts are designed at the forward end of the oar blades as a circular-cylindrical hinge part, and that the longitudinal grooves in the lower part are designed corresponding to the hinge part, and that the grooves are arranged to contain and retain the hinge part of the oar blade.

Preferred alternative embodiments are characterised by the dependent claims 2-11.

The rear end of the oar blade is preferably designed with an outwardly extending fin, where the fin is arranged at an angle to a middle section of the oar blade, set up to provide optimal pushing force/rudder force in the water.

The outwardly extending fin can be designed with a curved form. Furthermore, the main part of the oar blade can be given a mainly convex design, which, at its outer end, goes over into a reverse convex design. Said oar blades are preferably correspondingly mounted.

The lower end of the first power transmission rod can be made in the shape of a streamlined profile, whereby the profile and the oar blades, when these are closed, provide a completely streamlined cross-section profile, corresponding to the form of a fish.

The movement of the first power transmission rod about the horizontal axis is preferably provided with the help of a suspension unit secured to the vessel, such as the stern, and movement about the vertical axis is provided with the help of a bearing housing connected between the upper part of the first power transmission rod and the second power transmission rod. The bearing housing and suspension unit can be design as one unit.

The bearing housing can comprise a universal joint connected to the second power transmission rod and a transmission shaft connected between the upper part of the first power transmission rod and the universal joint.

Furthermore, the first power transmission rod can comprise a preferably forced motion hinge connection in an area adjoining and somewhat over the fastening area of the oar blades, arranged to steer the position of the oar blades in the water independently of the position of the first power transmission rod in the water.

The device is fastened to the stern of the vessel in an alternative embodiment.

The invention shall now be described in more detail with reference to the enclosed drawings, in which: Figure 1 shows a vessel with a device according to the invention, viewed from the side.

Figure 2 shows that shown in figure 1, viewed from above.

Figure 3 shows an embodiment of a device according to the present invention.

Figure 4 shows a section of an oar blade according to the present invention in closed position.

Figure 5 shows an exploded section of an oar blade according to the present invention in closed position.

Figure 6 shows a section of an oar blade according to the present invention in open position.

Figure 7 shows a section of an oar blade according to the present invention in an angled open position.

Figure 8 shows a section of an oar blade according to the present invention in an angled closed position.

Figure 9 shows a section of a tilt and suspension system according to the present invention.

Figure 1 shows a device according to the present invention in the form of a combi-oar 10, i. e. an oar arranged to be used as a system for propulsion, stabilisation and steering of a vessel 12. As the figure shows, the combi- oar 10 is preferably fastened to the vessel 12 with the help of a tilt and suspension system 16, so that the combi-oar 10 can be rotated about a vertical axis at the point of anchorage to the vessel at the same time as the combi-oar is able to pivot outwards from the anchorage point. It shall be noted that said vertical axis is approximately parallel with the anchorage point 14 to the vessel at the starting point for use of the combi-oar 10, but as the combi-oar 10 pivots out from the anchorage point the vertical axis will deviate from the parallel at an increasing angle a.

It shall be further noted that with the expression "backwards"or the like, is meant a direction opposite to the direction of propulsion of the vessel. Furthermore, it shall be noted that for figures 1-3, the direction of propulsion is towards the right in the figures and the direction of the flow of water is to the left, for figures 4 and 5, the direction of propulsion is to the left in the figures and the flow direction of the water is to the right, and for the figures 6-8, the direction of propulsion can be both to the right and the left. Further- more, with vertical axis is meant an axis that extends down along the stern of the vessel, and with horizontal axis, an axis that extends across the stern of the vessel.

In many cases it will be sensible that the anchorage point for the combi-oar is at the stern of the vessel, but the combi-oar can also be secured at other places on the vessel.

The tilt and suspension system 16 can comprise a bearing housing 18 fastened to the anchorage point 14 with the help of a suspension unit 19 for said movement of the combi-oar 10 in relation to the vessel 12. The suspension unit and the bearing housing can be in the form of one unit, or as two units as shown in figure 9.

The combi-oar 10 according to the invention preferably comprises a first power transmission rod 20 fitted on or to the bearing housing 18, where said power transmission rod 20 is hinged at its upper end and rotatable connected to a second power transmission rod 22 which in turn is fastened to a handle 24. The connection between the first and the second power transmission rod 20,22 is provided with the help of the bearing housing 18, such as, for example, a standard hinge, a universal joint, a ball joint, or the like. The bearing housing 18 will be described in more detail later. When the combi-oar 10 is to be used for propulsion of the vessel 12, the handle 24, and consequently the second power transmission rod 22, is led from and towards the anchorage point 14, mainly in a horizontal direction, corresponding to that shown by the arrow in figure 1. The first power transmission rod 20 is thereby pivoted outwards and pivoted forwards, respectively, about its anchorage point on the vessel, such as the stern 14. When the combi-oar 10 is to be used' for steering of the vessel 12, the handle 24 can, in one embodiment, be moved forwards and backwards across the longitudinal direction of the vessel, corresponding to that shown by the arrow in figure 2, or the handle 24 and the second power transmission rod 22 can be rotated, whereby the bearing housing 18 rotates the first power transmission rod 20 in a corresponding way, so that said power transmission rod 20 is rotated about said vertical axis. Of course, it can be natural to combine the propulsion movement and the steering movement to steer the vessel during propulsion.

Both the first and/or the second power transmission rod 20, 22 can, in an alternative embodiment, be designed as a telescopic rod, as shown in figure 3, to reduce the length of said rod 20,22.

Furthermore, the first power transmission rod 20 can comprise a preferably forced motion hinge connection (not shown) in an area adjoining and somewhat above the fastening area of the oar blades. The object of this hinge connection is, among other things, to be able to steer the position of the oar blades in the water independently of the position in the water of the first power transmission rod 20.

To provide said propulsion, steering and stabilisation of the vessel 12, the lower part 20a of the first power transmission rod 20 comprises a number of oar blades 26, preferably at least two oar blades 26a, 26b. The lower part 20a of the first power transmission rod 20 comprises a snout 28 which is pointing in the direction of propulsion of the vessel, having an increasing cross section shape towards the back. Furthermore, the lower part 20a comprises at least a longitudinal groove 30a, 30b on each side, arranged to receive the oar blades 26a, 26b.

The forward ends 32a, 32b of the oar blades are correspondingly designed as said groove 30a, 30b so that the oar blades are hinge-connected to the lower part 20a of the first power transmission rod 20. Alternatively, the lower part 20a can comprise two internal grooves for fastening of the oar blades 26a, 26b, arranged to provide a corresponding hinge function as described above, where the forward ends 32a, 32b of the oar blades can be correspondingly designed as said grooves. In this embodi- ment, the lower part 20a is designed so that the outwardly pivoting and inwardly pivoting movements of the oar blades cannot be obstructed.

As shown in the figures, the oar blade 26 extends back- wards in a mainly convex design, until an area adjacent the rear end 34 of the oar blade, where the oar blade goes over into a reversed convex design, i. e. with an outwardly extending fin 36 in relation to the rest of the oar blade.

When the oar blades 26a, 26b are closed, as shown in figure 4, a streamline design is thereby provided which can be compared to the shape of a fish. This streamlined design is excellent for bringing the combi-oar 10 forward to a position adjoining the anchorage point to the vessel 12 and for steering of the vessel.

The oar blades 26a, 26b are basically opened and closed automatically by movement of the oar blades backwards and forwards, respectively, because of the influence of the water. However, the opening and closing can be controlled with the help of an opening mechanism (not shown) that can lock the oar blades 26a, 26b in a closed or open position, or alternatively any position in between also. Use of the opening mechanism can be particularly relevant in relation to the steering and the stabilising function of the present invention. For example, the end 32a, 32b of the oar blades can be fitted with partially cogwheel-like appliances or other appliances that engage with each other, whereby the oar blades can be steered to a desired opening position with the help of the cogwheel-like mechanism. Other appliances arranged to force motion the movement of the oar blades can also be relevant.

In propulsion of the vessel, the handle 24 and the second power transmission rod 22 are pushed forwards as mentioned, and this leads to the first power transmission rod 20 being pivoted outwards and backwards from the anchorage point 14. Due to the design of the oar blades 26a, 26b and the forces from the influence of the water, the oar blades are consequently forced towards and into an open position, as shown, for example, in figure 6. A large surface that presses against the water is thereby provided, and this in turn leads to the vessel 12 being moved in the direction of propulsion. The height and length of the oar blades will be decisive for how large the area of said surface is, and can vary according to application and vessel. When the handle 24 is led backwards, the lower part of the first power transmission rod 20 is consequently forced forwards, and the oar blades are led, or forced, into a closed position, which consequently eases said forward movement.

The design of the oar blades 26a, 26b is especially advantageous in all the different functions of the present invention. For one thing, the streamlined design contri- butes to ease the forward movement of the combi-oar 10 during propulsion of the vessel. Furthermore, the design of the oar blades and in particular the shape of the outwardly extending fin 36, leads to the formation of turbulence in the water which affects the movement of the oar blades in the water. This can also be advantageous in the steering function and stabilizing function.

The design of the oar blade is, as mentioned, curved so that the water flow about it has the least resistance possible. The outer shape of the oar blade can follow the well-known Jawkovski shape, also known as the Nacca profile. The radius at the rear edge can be adapted according to need.

According to experience, the snout radius should be about 5% of the blade length, but other values are also used.

The form of the profile can be obtained from a suitable graph table or a conformal depicting function of the type w = z + 1/z, where Z is a complex function.

A bearing housing 18 and a suspension unit 19 as described above are shown in figure 9. The suspension unit 19 and the bearing housing 18 can alternatively be designed as one unit. The suspension unit 19 is fastened to the anchorage point 14, such as the stern of the vessel, and is arranged to suspend the combi-oar 10 and to contribute to the rotation of the first power transmission rod 20 about the horizontal axis with the help of, for example, a bearing 38. The bearing housing 18 is arranged to provide the rotation of the first power transmission rod 20 about the vertical axis. In a preferred embodiment, the bearing housing 18 comprises a housing 40 that contains a trans- mission shaft 42 for the transmission of the rotation of the second power transmission rod 22 to the first power transmission rod 20. Each end of the transmission shaft 42 is preferably fed through and mounted in a bearing 44, such as a thrust bearing. One end of the transmission shaft is connected to the first power transmission rod 20, and a second end of the transmission shaft is preferably connected to a universal joint 46 which in turn is connected to the second power transmission rod 22. The bearing housing 18 can, as mentioned, be designed in other ways, such as, for example, a standard hinge, a universal joint, a ball joint, or the like, arranged to provide corresponding power transmission and rotation as in the embodiment with the transmission shaft, or in a particularly simple embodiment, a rigid connection.

Figures 6 to 8 show the position of the oar blades both during a rowing function and/or when the combi-oar is used for a steering function or stabilizing function for the vessel.

In the main, the present invention is considered for use as a rowing function with the help of a person who pulls and pushes, respectively, the handle 24, but it can also be relevant to connect the second power transmission rod 22 to a type of motorised appliance that can provide a corresponding movement.

A basis for the forces of influence of the water on the oar blades is shown in appendix A. Results for flow analysis that are carried out on the combi-oar according to the present invention are shown in appendix B, for when the oar is closed and with water flowing in from the left, for a closed oar which is rotated at an angle a, for an oar that gets the flow of water from behind, and a description of the flow picture about an open oar, respectively.