DE3239441A1 - Fin box for a surfboard - Google Patents

Abstract

The invention relates to a fin box (1) for a surfboard in which a first mounting part (2) is firmly connected to the surfboard. A second insert element (3), to which the fin is firmly but detachably connected, is inserted from below into the mounting part (2) and is screwed to the mounting part (2) with screws (22). As a result, a bottom plate (16) and side walls (17, 18) of the insert element (3) bear in a positive-locking manner against the hat-profile margin (7) and inner and outer side walls (4, 9) of the mounting part (2) and are supported there. A fin (not shown) is fastened in a longitudinal gap (23) with side faces (24). To protect the fin of the surfboard and the mounting part (2), the connection between insert element (3) and mounting part (2) is designed as a predetermined breaking point which tears if a powerful force acts on the fin. This can happen by a screw (22) fracturing or by the insert element (3), which is dimensioned to be weaker, breaking before the fin or the mounting element (2) or the connection between it and the surfboard is damaged. For repair after collision damage, the connection between the insert element (3) and the mounting part (2) is then simply renewed or the relatively inexpensive insert element (3) is exchanged. <IMAGE>

Description

Fin case for a surfboard

The invention relates to a fin case for a surfboard according to the preamble of claim 1.

Surfboards are usually arranged with one roughly in the middle Sword and a fin attached to the rear end. Sword and Fin are used to maintain the direction of travel and stabilization. The sword is relatively large and extends quite deep into the water. It can be from above be inserted through the surfboard body and is used to protect against collisions pulled out upwards in shallow waters or bank zones or only when approaching plugged into deeper waters.

The back end of the surfboard with the fin on the underside is not so easy and straightforward for a surfer to ride reachable like the middle point where the sword is inserted. The fastening technology for the Finn therefore differs from that for the sword and is total more problematic, with a number of techniques known.

In many surfboard designs, the fin is in one in the surfboard body Embedded fin box is rigidly attached and is therefore immovable from the underside off the surfboard. There is a particularly flat area here when driving up quickly Waters on the fin, the risk of various damage. The biggest Damage occurs when the entire fin case is torn from the surfboard body becomes, whereby the surfboard is mostly unusable as a whole. Another common The damage that occurs is the rupture of the fin case, with cracks and ruptures Water can penetrate the surfboard body, so that depending on the internal structure Surfboard fills up and sinks. Less damage occurs if only The fin breaks But the fin is already a relatively expensive component of the Surfboard is quite expensive, even replacing a defective fin can be quite expensive especially if the attachment in the fin case cannot be easily removed is. The risk of damage is not only when driving into flat areas Waters, but also when transporting or storing the surfboard. To the Time, more and more large and long fins come onto the market who are driving in Immerse deeper and calmer water layers and thereby the board as a whole stable, which means that there is a great deal of leverage from the fin and the top named risk of damage are increased.

Another known type of attachment for fins is attempting damage thereby avoiding that the fin is movable in a longitudinal gap in the fin box and is spring-loaded. With one attacking from the front and lengthways Force, as it is usually exerted when driving onto the fin, works it through the gap in the surfboard body. In the unloaded position, it is controlled by the spring force folded out again.

This type of fastening is complex and therefore expensive and can also only against forces from the aforementioned Protect direction. Against forces acting on the side of the fin, such as when driving into bodies of water often occur with swell, the fin is not protected. Another Problem lies in the fact that the above-mentioned longer and larger fins in one rotatable holder on the one hand can only be kept directionally stable with difficulty and on the other hand the board body is insufficient to fold the fin is strong or an undesirably long gap is required for folding in the fin were.

The object of the invention, on the other hand, is to create a fin box, which, with a simple structure, provides effective protection for the surfboard and the fin in the case of forces acting on the fin, offers or only an insignificant and fast damage to be repaired occurs.

This task is in a generic fin box with the characterizing features of claim 1 solved.

According to claim 1, a fin box is constructed from two parts, wherein a first built-in part is firmly connected to the surfboard and a second Insert element, with which the fin is firmly but detachably connected, in this built-in part is used. The connection between the built-in part and the insert element is designed as a predetermined breaking point, which has the necessary strength for normal Has use, but tears out when high force is applied to the fin. The runaway can either be done so that the insert element with the fin from firmly with the Surfboard connected built-in part is separated or that the insert element as such breaks. The severed fin can therefore either be repaired in such a way that the fastening means between the insert element and the built-in part are renewed or that the relatively cheap insert element is replaced. So that both Surfboard and the integral part permanently connected to it and the fin safely protected from damage.

In claim 2 it is proposed that the insert element be screwed to connect with the built-in part. The breaking strength is then simply about the material and the strength of the screws used can be determined. Plastic screws are preferred used, with the necessary screw nut firmly attached in the built-in part can.

After the insert element has been torn out, the torn off screw shaft is then removed Easily accessible and can be rotated out of the nut for replacement. Appropriately two screw connections are provided on the longitudinal ends of the insert element. The predetermined breaking point that is only required to tear open more easily as the connection between the surfboard body and the built-in part and between the insert element and Finne, could also be through other types of connection, for example through a defined tear-open adhesive.

However, as already mentioned, it can also be produced by that the insert element breaks more easily than the fin or the built-in part or its Connection to the surfboard body.

With the features of claim 3 it is achieved that the bottom of the surfboard without increasing the flow resistance due to the fin case is continued.

According to claim 4, the built-in part is to have a hat profile edge with a circumferential Be provided edge projection on which a plate of the insert element form-fit rests within the edge protrusion. The large contact and contact surface created here provides a good stability of the connection between the built-in part and the insert element, thereby reliably preventing the insert element from wobbling, tilting and slipping will. On the other hand, there can also be a fixed connection between the surfboard body and the Built-in part can be achieved. The built-in part in this embodiment is, however, relatively difficult for surfers who make their own surfboard to be built in. Therefore, an embodiment without a hat rim is also provided, although does not have the advantages of the hat rim profile, but also does the surfboard and the fin is protected from damage.

A well-known and proven fin attachment can according to claim / transferred to the insert element as a fin attachment. It becomes through it a stable but easily detachable connection between the fin and insert element a screw connection is made, with a nut in a cage guide in the insert element respectively.

between the insert element and the built-in part is used as a further support a cross pin can engage in the fin.

According to claim 4> the side walls of the built-in part should be double-walled be executed and in the resulting space form-fitting support walls of the insert element can be inserted from below. This proposed connector contributes positively to stability.

In claim 7 an arrangement of ribbed chambers between the support surfaces of the longitudinal gap against which the inserted fin rests, and the Proposed support walls of the insert element. This will result in an execution of the insert element made of plastic material is saved and at high strength In addition, a kind of shock absorber between the fin and the insert element or

created the built-in part. The fin is then used during normal driving Stably held in its desired position, but it is something for small bumps resiliently mounted so that the predetermined breaking point does not tear open often undesirably.

The production of the proposed in claim AU also contributes to this Built-in part and the insert element made of plastic in the case of a suitable choice is somewhat flexible and yielding in itself, with no shape or guidance for the Finn to be lose. Another advantage here is the simple and inexpensive production of corresponding molded parts and the water and weather resistance.

On the basis of two exemplary embodiments, the invention is illustrated with further Features, details and advantages described in more detail.

1 shows a perspective view of a fin box with a partially cut built-in part and an insert element, FIG. 2 a View from below into one half of the built-in part, FIG. 3 shows a longitudinal section through half of the built-in part from FIG. 2, FIG. 4 shows a longitudinal section through the Half of an insert element, FIG. 5 is a plan view from above of the insert element according to Fig. 4, Fig. 6 a cross section through a built-in part, an insert element and a fin prior to assembly, FIG. 7 a cross section through a built-in part Insert element and a fin of a second embodiment prior to assembly.

In Fig. 1, a fin box 1 is shown, which consists of a built-in part 2 and an insert element 3 consists.

The built-in part 2 is made up of side walls 4, one facing downwards Enclose opening 5, and one placed on the side walls 4, hipped roof-shaped Upper part 6 built up. On the underside of the side walls 4, a circumferential one closes Hat profile edge 7, which in turn has an outer, circumferential and downward protruding Has edge projection 8. Run parallel to the longitudinal side walls 4 further side walls 9 offset towards the inside of the built-in part. The side walls 9 are connected to the upper part 6 and are free down to about halfway Height of the side walls 4 from, whereby a space 10 open from below between the side walls 4 and 9 is created. To stabilize the built-in part structure are transverse and longitudinally staggered bar constructions 11 attached. Furthermore, to increase the rigidity with minimal use of material, of the parts made of plastic here, interrupted by webs 12, side wall thinning intended.

There is a through hole 13 at each of the longitudinal ends attached, which in its upper part in a socket 14 for a screw nut 15 ends. The area around the bore 13 is shown here as a solid material construction, However, it could also be one that is customary in plastic injection molding technology and held by webs Be used pipe construction.

The insert element 3 is made up of a lower plate 16 and on it alongside extending side walls 17, 18 formed. At the long ends of the side walls 17, 18 is a pipe section 20 as a screw guide in a box-shaped part 19 held by webs 21. A slotted screw 22 can be pushed through the pipe section 20. In the middle of the insert element 3 extends in longitudinal direction a longitudinal gap 23, of which only one side surface 24 can be seen in FIG. 1 (for the longitudinal gap see Fig. 5 or Fig. 6). The side surfaces 24 of the longitudinal gap 23 are connected to the side walls 17, 18 via ribbed chambers 25.

The insert element 3 can be inserted into the built-in part 2 from below, so that the bore 13 and the screw guide 20 are aligned, the plate 16 form-fitting fits inside the edge projection 8 and the side walls 17, 18 into the spaces 10 can be inserted.

Fig. 2 shows a view from below into the built-in part 2. It is here again the hat profile 7 with the peripheral edge projection 8, the outer side walls 4 (indicated by dashed lines) and the inner side walls 9 with web constructions 11 to see. The screw guide mentioned above is from Stegs held pipe structure 26 used.

Fig. 3 shows a longitudinal section through the mounting part 2 with his Hat profile edge 7, the edge projection 8, the tubular structure 26 as a screw guide, the upper part 6 with the web construction 11, the inner side wall 9, the outer Side wall 4 and the screw socket 14 with an upwardly adjoining larger bore 27 for inserting the screw nut 15.

In Fig. 4 is a longitudinal section through the center of the insert element 3 shown, in which the ribbed chambers 25 also on the lower right side are cut. Here are the lower plate 16, the side surface 24 of the longitudinal gap 23, the side wall 18, the ribbed chambers 25, the pipe section 20 with a recess 28 for a screw head, and the walls of the box-shaped part 19 can be seen.

In Fig. 5 is a plan view from above of the insert element 3 is shown. Here is the longitudinal gap 23 with the ribbed chambers 25 as a connection to the Side walls 17, 18 can be seen.

From the cross-sectional representations of FIG. 6, the form-fit is clear The engagement of the insert element 3 in the built-in part 2 can be seen. The side walls 17, 18 of the insert element engage from below into the spaces 10 between the inner and outer side walls 9, 4 and are supported there. The top edges the side walls 17, 18 can, as shown here, be beveled for this purpose. Further the plate 16 fits into the recess created by the peripheral edge projection 8 is created.

The line 29 represents the height of the box-shaped edge part 19, which, in the assembled state, are at the level of the underside 30 of the side wall 9 comes to rest. However, the upper edge 31 of the chambers 25 is lower, so that in the assembled state between upper edge 31 and lower edge 30 a longitudinal slot persists. In this longitudinal slot (before assembly) a (not shown) Square nut introduced, which cannot be twisted in it.

The upper part of a fin 32 is also indicated in FIG. 6, wherein a retaining strip 34 is formed on the fin sheet 33. The retaining bar 34 corresponds in their shape the longitudinal gap 23, while the fin blade 33 at least in his middle area has a greater thickness. The holding bar 34 is in itself known way on the long sides over the fin blade and carries profiles there and holes for attachment.

The fin box 1 shown has the following function: The built-in part 2 is installed in a (not shown) surfboard body and fixed to it and inextricably linked. Then on the upper edge 31 of the Chambers 25 placed a square screw and pushed the insert element 3 into the mounting part 2 and screwed with the screw 22 at the longitudinal ends. After that, the Fin 32 pushed into the longitudinal gap 23 and its retaining strip 34 at one end with the square nut, which is supported on the upper edge 31 of the chambers 25, screwed. The other end of the fin 32 can through a gap in which a chamber 25 from below is open forth, with a cross pin in the retaining strip 34 on an upper edge of a Chamber 25 be pushed and held so. The holding bar 34 can at least be extended upwards in their central area, so that they are at the side Web of the web construction 11 (see Fig. 6), which is an extension of the side surfaces Form 24 upwards, supports.

Less strong forces acting on the fin 32, especially short, lateral joints, within the built-in part 2 and the insert element 3 in the chambers 25 and the double side walls of the built-in part 2 absorbed. Strength Effects of forces on the fin, especially strong forces that occur when driving up attack from the front of the fin 32, lead to a breakage of the correspondingly dimensioned Slotted screw 22, so that the fin 32 together with the insert element 3 from the built-in part 2 is pulled out. A loss of the Finn is only to be feared in exceptional cases, because the Finns can be found there at any time when driving into shallow waters can. For a repair then only the screw 22 (e.g. may contain a predetermined breaking notch). The material thicknesses for the wall parts should generally be dimensioned so that with a very strong Impact on the fin 32, the insert element 3 is more likely to break or break out than the built-in part 2 or parts thereof.

In Fig. 7 a second embodiment of a fin box is shown, which differs from the first embodiment only in that on the built-in part 2 no hat profile edge and no lower corresponding plate is provided on insert element 3 are. When plugged together, the underside of the insert element then closes 3 flush with the underside of the side walls of the built-in part 2. Otherwise is the installation in the surfboard, the assembly and the function the same as the first Embodiment.

Overall, the proposed fin box is a solution for Protection of the expensive surfboard and the fin in the event of raft impact on the fin shown.

Claims (7)

Claims 1. Fin case for a surfboard with one in the fin case attached fin, characterized in that the fin box (1) consists of a the surfboard firmly connected, elongated tub-shaped and in the installed state with its opening (5) facing the underside of the surfboard mounting part (2) and an insert element (3), with which the fin (32) is firmly but detachably connected and which is inserted into the built-in part (22), the connection between Built-in part (2) and surfboard and between the insert element (3) and fin (32) are essential is made more solid than between the built-in part (2) and insert element (3) and / or the mechanical skill of the insert element (3) is less than that of the built-in part (2) and the fin (32), so that between the built-in part (2) and insert element (3) and / or A predetermined breaking point is created in the insert element (3). 2. Fin box according to claim 1, characterized in that the Insert element (3) connected to the built-in part (2) via screw connections (15, 22) is. 3. fin box according to claim 1 or 2, characterized in that in the installed state with the outside of the insert element (3) the underside of the surfboard is continued without heels or protrusions. 4. fin box according to one of claims 1 to 3, characterized in that that the built-in part (2) has an edge (7) running around its opening (5), so that the built-in part (2) has the shape of a hat profile and the edge (7) on its Outside has a circumferential edge projection (8), and that the insert element (3) on its outside a plate (16) carries on the edge (7) of the hat profile and rests positively within the edge projection (8). iAL. Fin box according to one of Claims 1 to 5, characterized in that that the insert element (3) has an outwardly facing longitudinal gap (23) with internal Contains support surfaces (24) with an adjoining undercut nut guide and the connection between the fin (32) and the insert element (3) is known per se Way by inserting a retaining strip (34) molded onto the fin (32) into the Longitudinal gap (23) is made, the retaining strip (34) on the support surfaces (24) and by screwing it with a nut in the screw nut guide is attached. Fin box according to one of Claims 1 to /, characterized in that that at least in a partial area the side walls (4, 9) of the trough-shaped built-in part (2) are double-walled and form-fit in the resulting space (10) Retaining walls (17, 18) of the insert element (3) are inserted. 7. fin box according to one of claims 1 to, characterized in that that the support surfaces (24) of the longitudinal gap (23) and the support walls (17, 18) of the insert element (3) are connected via ribbed chambers (25). #. Fin box according to one of Claims 1 to, characterized in that that the built-in part (2) and the insert element (3) are molded plastic parts.