SURFBOARD WITH OVERLAP

Description

[0001] The invention relates to a surfboard having a hull component with a stern-side receptacle, a drive unit which fits positively into the stern-side receptacle and an underwater surface-side gap between the hull component and the drive unit.

[0002] Inflatable surfboards with a drive unit are known in the prior art, for example from DE 10 2015 103 503.0. The known surfboard has an inflatable hull component with a rear-end recess and a drive unit that fits and is inserted into the rear-end recess. A gap forms between the drive unit and the hull component on the underwater surface. The surfboard, propelled by the drive unit, can reach considerable speeds of 25 knots and more while underway. This creates a water current along the underwater surface of the surfboard and water pressure on the underwater surface of the surfboard, forcing water into the gap. This loosens the form-fitting connection between the hull component and the drive unit, unnecessarily increasing the water resistance of the board and significantly deteriorating the form-fitting connection.

[0003] From CN 205 675 195 U a surfboard with a continuous underbody plate, an inflatable hull and a drive component is known.

[0004] A surfboard with a separate drive component is known from CN 205 952 254 U.

[0005] JP 2003 026085 A discloses an inflatable surfboard with an inflatable U-shaped hull and a continuous underbody plate into which a drive can be inserted.

[0006] A surfboard with an internal combustion engine as drive is known from JP 2002 193185 A.

[0007] DE 10 2015 108 863 A1 discloses a surfboard with a two-part drive component that can be releasably attached to an inflatable hull component at the rear end using fastening means. The contours of the two-part drive component and the hull component are complementary. It essentially presents the same problems as the aforementioned prior art.

[0008] It is therefore an object of the present invention to provide a surfboard that avoids or at least reduces the above-mentioned disadvantages.

[0009] The problem is solved by a surfboard as mentioned above with the characterizing features of claim 1.

[0010] Preferred embodiments are the subject of the subclaims.

[0011] The surfboard according to the invention comprises a hull component with a rear-side recess, a drive unit which fits positively into the rear-side recess and is preferably already inserted into it, and a gap on the underwater surface side between the hull component and the drive unit, wherein an overlap is arranged on the underwater surface of the hull component which covers the gap at least in sections.

[0012] It has been shown that the ingress of water into the gap can be effectively reduced if an overlap is arranged on the underwater surface of the hull component, which covers the gap at least in section. It is not absolutely necessary to achieve a watertight seal against the surrounding water. However, the overlap has the function of preventing the water flowing along the underwater surface of the surfboard from entering the gap while the boat is in motion, but is instead directed along the underwater surface over the gap. This largely prevents water from entering the gap, and in addition, a slight suction effect can occur at the open end of the overlap, which even sucks out some of the water in the gap.

[0013] Advantageously, the hull component has two lateral arms that enclose the propulsion unit, preferably in a U-shape. The overlap is adapted to the shape of the gap, and the overlap is therefore also U-shaped and covers at least the bow-side section of the gap. Water has previously penetrated the most into the bow-side gap section, which is arranged transversely to the direction of travel, preferably perpendicularly. This can be effectively prevented. "U-shaped" is to be understood in general terms. A U-shape can be understood as a strict U-shape, but also as a shell shape, a rectangular shape, or similar.

[0014] According to the invention, the hull component is designed to be inflatable. Especially with inflatable hull components, the penetration of water into the gap leads to a widening of the gap and an increase in driving resistance because the hull component yields slightly under the pressure of the penetrating water.

[0015] The hull component can be made of a drop stitch material and is firmly inflatable.

[0016] The side walls of the hull are rounded and protrude towards the outside, i.e., they are convex. This convex shape of the hull is formed almost automatically by the fact that air is introduced into the hull under high pressure. The circumferential side walls of the drive unit are correspondingly concave. The width and length of the drive unit are selected so that they fit seamlessly into the recess. Despite the precise adaptation of the side walls of the drive unit to the inflated hull, a gap still forms between the hull and the drive unit, particularly exactly on the underwater surface. Water is forced into this gap during travel.

[0017] In particular, a section of the gap running transversely in the direction of travel is covered by the overlap according to the invention. The overlap preferably covers the entire transverse section of the U-shaped gap and at least partially covers the U-shaped side legs of the gap. Preferably, the overlap is connected as smoothly as possible to the underwater surface of the hull component on the edge facing away from the recess, for example, beveled, and glued or sewn directly to the edge, in particular the leading edge in the direction of travel of the surfboard, so that water cannot penetrate between the leading edge of the overlap and the hull component even in strong currents and, advantageously, the water resistance of the board is not increased by the edge.

[0018] According to the invention, a detachable fastening means is arranged between an inner side of the overlap facing the drive unit and the underwater surface of the drive unit.

[0019] "Inside" refers here and below to the orientation toward the drive unit or toward the U-shaped recess. A detachable connection, such as a hook-and-loop fastener, is arranged along the inside of the overlap on the side of the overlap facing the drive unit. This fastener interacts with a hook-and-loop fastener counterpart located on the underwater surface of the drive unit, thus additionally securing the overlap to the drive unit, at least detachably. This further reduces water penetration and also reduces the risk of the overlap increasing the board's water resistance.

[0020] To minimize additional flow resistance and ensure that the overlap covers the gap as effectively as possible, at least one attachment line is provided between the overlap and the fuselage component. Preferably, a nominal dimension of the attachment line of the fuselage component is larger than a nominal dimension of the attachment line of the overlap. The attachment lines of the fuselage component and the overlap are therefore not exactly identical. Rather, the fact that the attachment line of the fuselage component is slightly larger than that of the overlap allows the drive unit to be easily inserted into the fuselage component in the deflated state, and the overlap stretches smoothly when the fuselage component is fully inflated. This prevents wrinkling.

[0021] Preferably, the overlap is open toward the rear end. The advantage of an overlap open toward the rear end is that a slight Bernoulli effect can be created by the water flowing along the overlap and past the drive component, which essentially sucks water out of the gap.

[0022] The invention is described using an exemplary embodiment in six figures. In the figures: Fig. 1 a schematic sectional view of a conventional surfboard, Fig. 2 a detailed view of the gap between the hull component and the drive unit, Fig. 3 a sectional view according to Fig. 1 of the surfboard according to the invention with overlap, Fig. 4 a detailed view of the Fig. 3 , Fig. 5 a bottom view of the surfboard according to the invention with overlap between hull component and drive unit, Fig. 6 a view of the underwater surface of the surfboard according to the invention with overlap.

[0023] In the Fig. 1 and Fig. 2 Surfboards 1 according to the prior art are shown. The surfboard 1 has an inflatable hull component 2. In a plan view, the hull component 2 is essentially U-shaped in a rear section. A drive unit 3 is inserted into a U-shaped receptacle 4 of the hull component 2.

[0024] The fuselage component 2 can be made from a so-called drop stitch material. The drop stitch material is manufactured using the drop stitch process, in which two or more plastic fabric panels, preferably denier polyester fabric panels, are laid on top of one another. The two plastic fabric panels are connected to one another by a large number, i.e. thousands of polyester threads. The maximum distance between the two fabric panels is determined so that the space filled with polyester between the fabric panels can later be filled with compressed air and the fabric panels are largely parallel to one another. The polyester threads are sewn to both sides of the two fabric panels, for example using a drop stitch sewing machine. The two fabric panels sewn together form the supporting framework that gives the fuselage component 2 its mechanical strength when inflated.

[0025] The two interconnected fabric panels are cut to the desired shape. The upper and lower fabric panels are coated with PVC layers, preferably three layers, pressed and glued in layers. The sides are overlapped and glued with seam tape to form the airtight fuselage component 2.

[0026] The drop stitch process enables the inflatable hull component 2 to be manufactured with excellent mechanical strength properties that can withstand high tensile, compressive, and shear loads. The drop stitch outer skin of the inflatable hull component 2 is airtight and, when inflated, extremely deformation-resistant, allowing a surfer to stand and surf on the hull component 2 while maintaining the external shape of the inflated hull component 2. The hull component 2 is filled with high-pressure air. Inflation can be achieved using an air pump or a compressor. The compressor can be powered by electrical energy from accumulators built into the surfboard 1.

[0027] The hull component 2, made of drop-stitch material, is preferably sound-dampening, so that the noise generated by wave action, as well as by the propulsion, is dampened by the hull. The hull component 2 is low-vibration during operation because the drop-stitch material reduces vibrations. Since the hull component 2 is somewhat deformable, shocks from waves, etc., are advantageously absorbed. Another advantage over conventional surfboards 1 is that the softer hull causes fewer injuries, e.g., if the surfboard 1 collides with the surfer when the surfer falls off.

[0028] The rear area of ​​the hull component 2 has the receptacle 4 for the drive unit 3. The drive unit 3 can comprise a jet drive. The jet drive comprises an opening for the water inlet on an underwater surface 7 of the drive unit 3 and a water channel to the rear end face of the drive unit 3. The water outlet can be formed there by a nozzle. The nozzle can be pivotable or fixed.

[0029] A rotor is provided in the water channel. Due to its high rotational speed, the rotor sucks water into the water channel and sprays it out backward through the nozzle, thus providing propulsion to the surfboard 1. The rotor is connected via a drive train to a motor, preferably an electric motor, which can be controlled via a controller if necessary and is powered by the accumulator. The drive unit 3 is entirely interchangeable. The term "rotor" is to be understood broadly here. It can refer to a propeller, an impeller, or similar.

[0030] A gap 6 is formed between the drive unit 3 and the hull component 2. Since the hull component 2 is convex into the receptacle 4 along an inner side wall that runs approximately three-quarters around the drive unit 3, an outer circumference of the drive unit 3 is adapted to this contour by a concave design, but this adaptation can never be so precise that no gap 6 is formed, in particular not directly on the water surface 7, at the butt joint between the hull component 2 and the drive unit 3. The gap 6 is in the Fig. 2 The arrows are exaggeratedly wide. However, the problem becomes apparent: as surfboard 1 travels, water is literally pushed into gap 6 due to the flow velocity. The water flow is represented by the longer arrows. The direction of travel F of surfboard 1 is indicated by a wide arrow.

[0031] Fig. 3shows the surfboard 1 according to the invention, which has an overlap 8 on the underwater surface 7. The overlap 8 is a flap made of PVC, PE, PET or another plastic material, which is also shown in a plan view essentially according to Fig. 5is U-shaped and covers the gap 6 at least in sections. The overlap 8 can also be made of leather or other natural materials or even a metal foil. The overlap 8 is provided in particular for a gap section 6a which is positioned transversely in the direction of travel F and is located between a leading edge of the drive unit 3 in the direction of travel F and a corresponding, transverse inner wall 2a of the fuselage component 2 and completely overlaps the transverse gap section 6a. The flap 8 is firmly sewn, glued or welded to the fuselage component 2. For this purpose, a welding, adhesive or seam line 9 is provided, or several welding, adhesive or seam lines 9 are provided, which follow or follow the edge 11 of the overlap 8 facing away from the holder 4.The edge 11 leading to the overlap 8 in the direction of travel F or running alongside it is preferably bevelled in the direction of travel F and glued to the hull component 2 along the entire edge 11, so that even during travel due to the water flow no water can penetrate between the underwater surface 7 of the hull component 2 and the overlap 8, but the water flow according to . Fig. 4 under the flap. The overlap 8 is detachably connected to the drive unit 3 in a section that overlaps with the drive unit 3; for this purpose, a hook and loop fastener 12 according to Fig. 3 or similar may be formed between the edge of the overlap 8 facing the drive unit 3 and the drive unit 3.

[0032] The overlap 8 preferably lies tightly against the underwater surface 7 of the drive unit 3 without any wrinkles.

[0033] Fig. 6shows the overlap 8 in a bottom view. The bottom view shows the U-shaped receptacle 4 formed by the hull component 2. Inflatable arms of the hull component 2, circular in cross-section perpendicular to the direction of travel F, are arranged laterally on the drive unit 3 and encompass the drive unit 3 between them. On the part of the drive unit 3 leading in the direction of travel F, the overlap 8 is connected to the hull component 2. This overlap does not necessarily completely cover the gap 6, but completely covers the gap section 6a running transversely, preferably perpendicular, to the direction of travel F, into which a particularly large amount of water has conventionally penetrated. List of reference symbols

[0034] 1Surfboard 2Hull component 2aInner wall 3Drive unit 4Mounting 6Gap 6aGap section 7Underwater surface 8Overlap 9Weld or seam line 11Edge 12Velcro fastener Direction of travel

Claims

1. Surfboard with an inflatable hull component (2) with a receptacle (4) at the stern end, a drive unit (3) which fits into the receptacle (4) at the stern end in a positively locking manner, a gap (6) on the underwater surface between the hull component (2) and the drive unit (3) and an overlap (8) is arranged on an underwater surface (7) of the hull component (2) which covers the gap (6) at least in some sections, characterised in that a releasable fastening means (12) is arranged between an inner side of the overlap (8) and the underwater surface (7) of the drive unit (3), which is used to connect the overlap (8) with the drive unit (3) in a releasable manner.

2. Surfboard according to claim 1, characterised in that the hull component (2) has two lateral arms which engage in a U-shape around the drive unit (3), and the overlap (8) is likewise U-shaped and at least covers the section of the gap (6) at the bow end.

3. Surfboard according to one of claims 1 to 2, characterised in that a fastening line is provided between the overlap (8) and the hull component (2) and a nominal dimension of the fastening line of the hull component (2) is greater than a nominal dimension of the fastening line of the overlap (8).

4. Surfboard according to one of claims 1 to 3, characterised in that the overlap (8) is open towards the stern end.

5. Surfboard according to one of claims 1 to 4, characterised in that on the leading edge in a direction of travel (F) the overlap (8) is chamfered towards the underwater surface (7).