DE102021001355A1 - Arrangement for slidably positioning a fin in a fin box - Google Patents

Abstract

The invention relates to an arrangement for displaceably positioning a fin in a fin box. The fin head is shortened and can be fixed in the fin box with more than one thread (insert).

Description

The present invention relates to a modified power box fin system for watercraft, in particular windsurfing boards, consisting of the power box or fin box provided in the watercraft and an assignable, replaceable fin.

To simplify the description, windsurfing boards or surfboards are always spoken of below. However, it should be understood that this reference is not intended to be limited to windsurfing boards in particular, but includes any board for water sports.

So-called fins are installed in windsurfing boards to stabilize the direction. In addition to directional stabilization, their task is also to absorb lateral forces that are generated by the drive device, in this case the sail.

In the leisure sector, a so-called power box is very often used, which allows the fin to be easily installed and removed.

A power box fin system is defined by the fact that a screw is passed through the board from above to lock the fin in the fin box, for which purpose a single screw thread is provided in the middle of the web (head) of the fin and the fin head otherwise fits snugly into the fin box in terms of size is.

Since the position of the fin in relation to the longitudinal direction of the board in the direction of the bow or stern is thus fixed, it is not possible to trim the surfboard depending on the prevailing wind and wave conditions, which in itself is a disadvantage. An adjustment of the board/sail/driver/fin ratio is also not possible.

This problem was known in the state of the art and had already been solved by fins that could be slidably arranged, for example in so-called trim box systems. However, these require a special design of the fin boxes. The prior art may, for example, on the DE 41 22 000 C1 or the DE 29 33 802 A1 .

The known systems require a considerable manufacturing outlay in that the fin boxes, which are defined for each board, have to be specially designed for the possibility of changing the position and locking a fin.

The idea of the present invention is to further develop a conventional power box system in such a way that the fin can be arranged in a longitudinally displaceable manner in the power box without having to change the power box or the windsurfing board itself.

According to claim 1, the subject matter of the present invention is a power box fin system, consisting of a fin box, also called power box, provided in a watercraft, in particular a surfboard, and a fin with a fin head. The power box fin system according to the invention is characterized in that the fin head is reduced in relation to the dimensions of the fin box, at least two threads (inserts) are provided in the fin head in the longitudinal direction of the head and spaced apart from one another, such that the fin can be screwed in by means of a So-called fin screw guided in the surfboard can be locked in different positions in the bow or stern direction on the surfboard, the fin head being shortened in the longitudinal direction of the fin and with respect to the longitudinal dimension of the fin box.

The advantage of the power box fin system according to the invention is that existing fin boxes/windsurf boards can be retained unchanged and the fin can still be adjusted in its longitudinal position, ie lengthwise to the board.

In the context of the present invention, the fin head is shortened in the longitudinal direction of the fin, in principle on the front and/or rear side, and with respect to the longitudinal dimension of the fin box. This measure allows the fin to be moved in the fin box and positioned in different positions towards the bow or stern. This requires a simple and low amount of work for the assembly of the fin, which makes the use of such a power box fin system much easier for amateurs.

Preferred embodiments emerge from the dependent claims.

According to claim 2, filling/clamping pieces are provided which engage the fin head at the front and/or rear, stabilize it in position and form a smooth underwater surface of the surfboard. The benefits here are self-explanatory.

According to claim 3, the fin head also has a lower height than the fin box. This further optional feature enables a further modification of the previously known Powerbox fin systems in terms of the fin used. If necessary, the lack of height can be compensated for by an additional, horizontally aligned filler piece, again without having to influence the construction of the fin box and the board in any way. This filler piece is mainly used to bring the top of the fin head into position in any position.

In order to enable the possibility of changing the position of the fin in the fin box, at least two threads (inserts) are provided in the fin head. However, the greater the number of threads (inserts) provided, the greater the possibility of changing the position of the fin in the bow or stern direction and thus the effect on the behavior of the surfboard. However, the number of positions is limited by the dimensions of conventional fin boxes and fins.

According to claim 4, three threads (inserts) are advantageously provided in the longitudinal direction of the fin head at equal or unequal distances from one another. It can be assumed that most wind and wave conditions can also be taken into account with regard to the user's driving skills.

The person skilled in the art will understand threaded inserts as (metal) bolts provided in the fin head with a thread formed therein, which prevent the screw from tearing out due to better material strength and material consistency. Of course, forming the thread directly into the fin head is also conceivable.

It is also of great advantage if, according to claim 5, the fin head and the filling/clamping pieces and optionally a horizontally aligned filling piece are designed for mutual engagement. For this purpose, for example according to claim 6, undercuts are provided on the front and/or rear side of the fin head and corresponding material projections or noses on the filling/clamping pieces, also vice versa, which can then engage in one another in a form-fitting manner. The undercuts and projections can be more or less strong, from a few millimeters up to a centimeter. They can either only be present on the front side or only on the rear side or, advantageously, on both sides.

According to claim 7, the fin head and the filling/clamping pieces are advantageously designed for mutual engagement in such a way that the filling/clamping pieces are interchangeable on the front and rear sides. This means that fewer filling/clamping pieces are required while at the same time there is a greater possibility of variation in their use.

According to claim 8, the filling/clamping pieces (8, 8' and 9, 9') are dimensioned in such a way that, when in use, they fill the fin box with the fin head in a form-fitting manner without play. It would also be conceivable to use a further spreading element, which prevents the filling/clamping pieces from slipping or loosening.

According to claim 9, the filling/clamping pieces are advantageously designed as hollow and/or solid bodies. Hollow bodies mean savings in material and lightness, while solid bodies always mean greater strength/stability.

To increase the clamping effect, it is advantageous according to claim 10 if the filling/clamping pieces are made of a rigid or flexible material, which makes their installation much easier.

In a further advantageous manner, according to claim 11, the filling/clamping pieces are provided with a bore which, according to claim 12, is oriented diagonally in the filling/clamping pieces. On the one hand, these features make it easier to remove the filling/clamping stones from the fin box and, on the other hand, the holes are no longer in the water flow, which could disadvantageously lead to turbulence around the fin.

According to claim 13, at least one of the front and/or rear filling/clamping pieces can advantageously be combined with the horizontally aligned filling piece to form one component. Here, too, the advantages, less filling/clamping pieces required, easier handling, are self-evident.

An advantageous embodiment of the invention also results when the horizontally aligned filler piece is held captive by a fin screw in the fin box, the fin screw being partially turned towards the screw head and a sleeve arranged in the fin box/turned area prevents the filler piece and screw from falling out, as soon as the fin is otherwise dismantled. Screw and filler remain connected to the surfboard and are always ready for use.

Preferably, the fin head and the filler/shims are designed to engage with one another such that the filler/shims are interchangeable. The latter feature makes it possible to provide a set of filling and clamping pieces according to claims 15, 16 and 17 for different positions of the fins.

• 1 einen Längsschnitt durch ein Surfbrett mit darin angeordnetem Finnenkasten und einen Finnenkopf mit einem Gewindeeinsatz zur Aufnahme einer Schraube (Powerbox-System);
• 2 einen Längsschnitt durch ein Surfbrett mit darin angeordnetem Finnenkasten und einen erfindungsgemäß ausgebildeten, verschiebbaren Finnenkopf mit drei Gewindeeinsätzen zur wahlweisen Aufnahme einer Schraube sowie Füll-/Klemmstücke (modifiziertes Powerbox-System) ;
• 3 ein modifiziertes Powerbox-System gemäß 2 mit unverlierbar gehaltener Finnenschraube gemäß der Erfindung;

The invention is explained in more detail below with reference to drawings. It shows:

• 1 a longitudinal section through a surfboard with a fin box arranged therein and a fin head with a threaded insert for receiving a screw (power box system);
• 2 a longitudinal section through a surfboard with a fin box arranged therein and a movable fin head designed according to the invention with three threaded inserts for optionally receiving a screw and filler/clamping pieces (modified power box system);
• 3 a modified Powerbox system according to 2 with captively held fin screw according to the invention;

In 1 a conventional power box system is shown as currently used in a variety of windsurfing boards. It shows a fin head 5 with a thread (insert) 6 which is inserted into a fin box 3 . A screw (not shown) for fastening the fin 4 into the fin box 3 can be inserted via a bore 10 in the windsurfing board 2 . The fin box 3 is flattened in one direction, that is to say it has a lower height at one end, its rear end according to the shape of a windsurfing board, than at the other bow end. An adaptation to the profile of the board 2 is thus achieved. The fin head 5 is adapted to the dimensioning of the fin box in such a way that positive mounting and engagement (clamping) is possible.

As already explained, the disadvantage of this conventional power box system is that the position of a fin on the board is fixed and it is therefore not possible to influence the wind and wave conditions and the like. This problem is solved in a simple and cost-effective manner with the present invention.

2 shows the power box system 1 modified according to the invention in a longitudinal section as in FIG 1 . Identical reference numbers refer to identical features as in 1 .

A fin box 3 is formed or incorporated in the windsurfing board 2, which in terms of shape and size is a conventional, in 1 corresponds to the standard fin box shown. A fin 4 with a reduced fin head 5 according to the present invention is arranged in the fin box 3 . Of course, the fin head 5 shown forms the fin 4 together with a fin blade 4', which is only shown schematically.

The fin head 5 is shortened in its longitudinal direction at the front and rear and in height. The upper sides 5' and 5" of the fin head 5 are machined in such a way that they lie against the filler piece 7, which on one side depicts the contour of the fin box 3 and on the other side has contact surfaces parallel to the underwater hull, on which the fin head 5 can slide The bow-side contact surface is preferably higher so that the bending moment generated by the fin 5 can be better transmitted to the fin box 3 .

In other words, the tops 5', 5'' of the fin head 5 are machined so that one end can be abutted against a higher part of the fin box 3 and the other end against the lower part of the fin box 3, with the base 5' '' of the fin head 5 is aligned with the bottom side of the windsurf board (underwater hull).

In the embodiment shown, a horizontally aligned filler piece 7 is inserted between the top 5', 5" of the fin head and the inside of the fin box 3. This filler piece 7 can also be in several parts. It not only serves to compensate for the height difference between the fin head 5 and the fin box 3 Since the fin head 5 is shortened in height in such a way that two different levels, corresponding to 5' and 5", are formed, the filler piece 7 forms counter bearings on which the fin head 5 can be moved into each of the three predetermined positions while maintaining the contact pressure can.

A hole 10 is provided in the surfboard 2 above the fin box 3 and also penetrates the fin box 3 and the filler piece 7 . In the fin head 5 are shown 3 threads (inserts) 6 for three positions of possible attachment of the fin 4 longitudinally and shown arranged equidistantly. The distance between the threads (inserts) 6 could also be different or there could be more than three threads (inserts) 6 for more positioning possibilities. The threaded (inserts) 6 each have an internal thread with which a screw 12 guided through the bore 10 (not shown here) can be brought into operative connection.

Furthermore, in 2 Filler/clamping pieces 8.8' and 9.9' are shown, which are inserted into the fin box 3 together with the reduced fin head 5. The filling / clamping pieces 8.8 'and 9.9' have lugs / projections or undercuts, which are provided in the same or corresponding manner at the bow and / or rear ends of the fin head 5, such that the filling -/Clamping pieces 8.8' and 9.9' can be engaged with one another with the bow and/or the stern ends of the fin head and can be inserted into the fin box 3.

Which of the filling/clamping pieces 8.8' and 9.9' are used depends on the desired positioning of the fin head 5 in the fin box 3. The central position shown here corresponds, for example, to the position of the fin supplied as standard.

In the case shown, the filling/clamping pieces 8' and 9' could be used. Corresponding configurations can be derived for the further bow and stern positions in the form of the filler/clamping pieces 8 and 9.

Not shown is a diagonal hole 11 which ideally should be provided in the filler/clamp pieces. Such a diagonal bore makes it easier to remove at least one of the filling/clamping pieces and thus all other filling/clamping pieces when changing and/or removing the fin.

A set according to the invention, comprising a fin 4 with a reduced fin head 5 and filling clamping pieces 7, 8.8' and 9.9', can be used in all conventional power box systems and can therefore be used both as a supplement and as a replacement.

In 3 the modified power box fin is also shown in a further embodiment according to the invention. A fin screw 12 is introduced via the bore 10 in the windsurf board 2 and the fin box 3 and brought into engagement with the fin head 5 by means of the thread 6 . The fin screw 12 is turned towards the screw head 13, ie its diameter is reduced. A sleeve 14 is arranged in the turned area, which comes to rest within the fin box. After the fin 5 has been removed from the fin box 3, the fin screw 12 is held captive in the fin box 3 or on the windsurfing board, and with it, if necessary, filler pieces 7, 7'.

The present invention is shown using preferred embodiments. It is understood that modifications thereof are possible that are encompassed within the scope of the disclosure.

Reference List

1

Powerbox system

2

surfboard

3

fin box

4

fin

5

fin head

5' and 5"

tops of the fin head

5'''

Base of the fin head

6

thread (inserts)

7

horizontal filler piece

7' 7 with 8.8' or 9.9'

combined component

8.8' and 9.9'

filling/clamping pieces

10

drilling

11

diagonal hole

12

captive fin screw

13

screw head

14

sleeve

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 4122000 C1 [0007]
• DE 2933802 A1 [0007]

Claims (17)

Powerbox fin system (1) consisting of a fin box (3) provided in a watercraft, in particular a windsurf board (2), and a fin (4) with a fin head (5), characterized in that the fin head (5) in relation to the dimensions of the fin box (3) is reduced, in the fin head (5) in the longitudinal direction of the head and at a distance from one another at least two threaded (inserts) (6) are provided, such that the fin (4) can be screwed in by means of a hole (10) in The screw (12) guided on the surfboard (2) can be locked on the surfboard in different positions in the bow or stern direction, the fin head (5) being shortened in the longitudinal direction of the fin (4) and with respect to the longitudinal dimension of the fin box (3). Powerbox fin system according to claim 1 , characterized in that filling/clamping pieces (8,8' and 9,9') are provided, which additionally engage the fin head (5) and form a smooth underwater surface of the surfboard (2). Powerbox fin system according to claim 1 and/or 2, characterized in that the fin head (5) has a lower height than the fin box (3), the difference in height between the upper side (5', 5") of the fin head (5) being compensated for by a horizontally aligned filler piece (7 ) while maintaining a mobility of the fin head (5) is compensated. Powerbox fin system according to each of the Claims 1 until 3 , characterized in that three threaded (inserts) (6) are provided in the longitudinal direction of the fin head (5) at equal or unequal distances from one another. Powerbox fin system according to each of the Claims 1 until 4 , characterized in that the fin head (5) and the filling/clamping pieces (8,8' and 9,9') are designed for mutual engagement. Powerbox fin system according to claim 5 , characterized in that the mutual engagement of fin head (5) and filling/clamping pieces (8,8' and 9,9') is realized by forming undercuts and/or lugs/protrusions thereon, respectively. Powerbox fin system according to each of the Claims 5 and 6 , characterized in that the fin head (5) and the filling/clamping pieces (8,8' and 9,9') are designed for mutual engagement in such a way that the filling/clamping pieces (8,8' and 9,9' ) are interchangeable. Powerbox fin system according to one of Claims 5 until 7 , characterized in that the filling/clamping pieces (8.8' and 9.9') are dimensioned in such a way that they fill the fin box (3) in a form-fitting manner with the fin head (5) when in use. Powerbox fin system according to one of Claims 5 until 8th , characterized in that the filling/clamping pieces (8.8' and 9.9') are designed as hollow and/or solid bodies. Powerbox fin system according to each of the Claims 5 until 9 , characterized in that the filling / clamping pieces (8.8 'and 9.9') are formed from a rigid material. Powerbox fin system according to any of the preceding Claims 1 until 10 , characterized in that the filling/clamping pieces (8.8' and 9.9') are provided with a bore (11) for their removal from the fin box (3). Powerbox fin system according to claim 9 , characterized in that the bore (11) is made diagonally in the filling/clamping pieces (8.8' and 9.9'). Powerbox fin system according to any of the preceding Claims 1 until 12 , characterized in that at least one of the filler pieces (8.8' and 9.9') is combined with the horizontally aligned filler piece (7) to form one component (7'). Powerbox fin system according to any of the preceding Claims 1 until 13 , characterized in that the filler piece (7,7') is held captive by the fin screw (12) in the fin box (3), the fin screw (12) being partially turned towards the screw head (13) and one in the fin box (3) and the sleeve (14) arranged in the turned area prevents the filling piece (7, 7') and screw (12) from falling out. Set for a Powerbox fin system according to the claims 1 until 14 , comprising a fin (4) with a reduced fin head (5) and filling/clamping pieces (8.8' and 9.9'). Set for a Powerbox fin system according to Claim 14 , comprising a fin (4) with a fin head (5) that is reduced in height and in the longitudinal direction, filling/clamping pieces (8.8' and 9.9') and a filling piece (7). Set for a Powerbox fin system according to claim 15 , wherein one of the filling and Klemmstü cke (8.8 'or 9.9') is combined with the filler piece (7) to form a component (7').

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