EP0035293B1

EP0035293B1 - Multi unit surf-board such as a tandem surf-board formed by at least two mono surf-boards

Info

Publication number: EP0035293B1
Application number: EP81200153A
Authority: EP
Inventors: Jan Bos
Original assignee: Polymarin BV
Current assignee: Polymarin BV
Priority date: 1980-02-11
Filing date: 1981-02-06
Publication date: 1984-05-23
Also published as: DE3163702D1; EP0035293A2; EP0035293A3; NL8000841A; AU7477981A

Description

Multi unit surf-board such as a tandem surf-board formed by at least two mono surf-boards.
The invention relates to a multi unit surf-board such as a tandem surf-board formed by at least two mono surf-boards, having more than one mast and sail, comprising interconnectable parts which can be disconnected.
A multi unit surf-board of this type is known from US patent specification 4,100,870. Said known multi unit surf-board can have the form of a tandem surf-board formed by two mono surf-boards by means of a special interconnecting or coupling portion by means of which the two stern ends of the two mono surf-boards can be interconnected to form a tandem surf-board. This known tandem surf-board has the advantage that it can be composed of two mono surf-boards suitable for mono sailing which mono surf-boards can be combined to a tandem surf-board if so desired. This desire exists because a tandem surf-board enables higher speeds.
A disadvantage of said known multi unit surf-board, however, is that a special connecting piece is necessary which not always is available and requires a special shape of the stern whereas when mounted in tandem the second surf-board by being mounted in the opposite direction has an unfavourable flow profile.
Tandem surf-boards made from one piece and having two or more masts are known as well but they have the disadvantages that transportation no longer can take place upon the roof of a motor vehicle, that the price is high and that they only can be used if there are sufficient participants, which have to be present at the same time.
Purpose of the invention is to provide a multi unit surf-board formed by at least two mono surf-boards the owners of which at will can use said mono surf-boards as such or can combine them to a tandem surf-board or even multiple surf-board.
According to the invention this purpose is achieved in that each one of said parts is formed by a complete mono surf-board each being formed at its stern and stem respectively such that the stem of a next surf-board by its form fits into the stern of a preceding surf-board and the reverse.
Accordingly each part itself is a mono surf-board and said parts fit into each other like a male-female construction due to which they can be interconnected in any desirable number without disturbing the properties when used as mono surf-board. Each surf-board has a stern of a form such that the stem of an identical surf-board can be enclosed and mounted into it. In this way two or more surf-boards in a simple way can be interconnected to a multiple surf-board. The sailing properties of the mono surf-board are affected neither by the shape of stem and stern nor by the recess in the stern. If the surf-boards are combined to a multiple surf-board then in the same way as with known surf-boards a multiple sail surface is obtained without considerable increase of the resistance within the water. Due to this the possibility is obtained to form combined surf-boards by means of a surf-board which need not to cost more than a normal mono surf-board and due to this an additional dimension can be given to the surf sailing sport without increasing its costs.
An additional coupling member is not necessary.
The advantages accordingly are:

a with respect to the tandem surf-board made from one piece no longer transportion problems exist;
b each part can be used as mono surf-board;
c the interconnection is very simple; tools are not necessary; can take place if so desired within the water.
d Disconnection also can take place at any moment;
e If a surf-board according to the invention is bought the problem of the choice between mono surfing or tandem surfing disappears because with one type both possibilities can be achieved.
f The users are independent from each other:
g From a sporting point of view it is of great importance that the owner of a mono surf-board according to the invention for the price of one surf-board at any moment can change over to tandem surfing as soon as he finds someone else having the same surf board and the same desire. The reverse is true as well.

Although it is preferred that the surf-boards which according to the invention can be interconnected to a tandem surf-board or a multiple surf-board, are entirely identical, the invention also relates to those surf-boards which are identical at stern and stem but inbetween different to be able to combine junior surf-boards with surf-boards for grown-up people. It even is possible to combine surf-boards which are not identical at all but of which one has a stem which fits into the stern of another surf-board.
The mono surf-board suitable to be combined to a multiple surf-board at the location of the front end of the recess and at the location of the stem is provided with connecting members which together form a connection. By the form fitting insertion of this stem in the recess of the stern relatively few and simple connecting means are sufficient. Often a connection of the stem in the front end of the recess will already be sufficient. However, one also can provide members at the rear ends of the legs of the stern extending on both sides of the recess which lock against upward movement a stem placed in said recess.
According to the invention the connection can be obtained by providing those parts of stem and stern which fit upon each other at least locally with the complementary parts of a velcro fastener. Velcro fasteners have the advantage to enable a quick connection which gives way however upon overloading.
According to the invention the connection between the front end of the stem and the front end of the recess can be obtained in that the surf-board at the front end of the recess as well as at the stem is provided with connecting members which together form a connection.
Instead of said connections or in addition thereto it is possible that the stern at the front end of the recess and/or at the rear ends of the legs of said stern is provided with cams extending above the recess and adapted to engage the top surface of a stem placed within the recess. Due to this in combination with the upwardly inclined side faces of the legs of the recess which side faces deliver a locking downwardly, a locking in all directions is obtained and provisions then still only are necessary to prevent disengagement in axial direction. This can be achieved by means of the above mentioned pin connection but also in that one or more of the cams are provided with a vertical bushing for a pin and the stem at the locations which come to lie below the cams has been provided with a bushing, which bushings are in line if a stem is placed in the recess of a stern. Further the enclosure between the rear ends of the legs of the recess independent from the above-mentioned connecting means or in addition thereto so can be obtained by interconnecting said legs by means of a tension belt running over the top surface of a stem placed or to be placed in the recess and pressing this stem against the legs of the stern of the preceding surf-board.
Surf-boards having centre boards are well known and it is also known that such a centre board is removably inserted within a longitudinal slot. The surf-board according to the invention can be provided as well with such a removable centre board. This is desirable not only for transportion purposes, as is well known, but to prevent that too many centre boards effect the steerability of a combination of two or more surf-boards according to the invention.
According to a preferred embodiment of the surf-board according to the invention the surf-board at its stern is provided with a hollow space which, with the exception of the rearwardly open insert opening is closed in principle and has an inner shape which is equal to the outer form of the stem and that openings are provided in the stem and in top and bottom portion of the stern of a form and location such that in case a stem is placed into the stern opening both surf-boards are interconnectable by a connecting member which can be inserted through the in line lying openings. Such a connecting member can be a pin or a plurality of pins but preferably said openings are formed by longitudinal slots and the connecting member has the form of a centre board such as e.g. one of the centre boards of the two or more mono surf-boards which are to be interconnected. In this way without additional elements a tandem surf-board can be obtained having the same or almost the same steering qualities as a mono surf-board.
The invention now will be further elucidated with reference to the drawings.

Figure 1 shows two interconnected surf-boards according to the invention.
Figure 2 is a side view of a surf-board according to the invention.
Figure 3 is a top view of the surf-board of Figure 2.
Figure 4 show a sequence of cross sections or the timber plan of the surf-board of Figure 2 or 3 respectively.
Figure 5 shows a side view of an interconnecting possibility between two surf-boards.
Figure 6 is a top view of Figure 5.
Figure 7 is a cross section according to the line VII-VII of Figure 6.
Figure 8 is a longitudinal cross section according to the lines VIII-VIII of Figure 6.
Figure 9 is a cross section according to the line IX-IX of Figure 8.
Figure 10 is a cross section according to the line X-X of Figure 8.
Figure 11 is a top view of another embodiment.
Figure 12 is a side view of the surf-board according to Figure 11.

Figure 1 shows a tandem surf-board comprising a front surf-board 1, a second surf-board 2. The surf-board 1 has been provided with a mast 3 with sail 4 and the surf-board 2 with a mast 5 with sail 6. At 7 an insertable centre board has been provided formed by a plate mounted within a slot provided for that purpose. This is well known. The surf-board 1 has a similar slot and if so desired a centre board can be inserted there as well.
The Figures 2 and 3 show one of the surf-boards of Figure 1 at larger scale. In said figures at the location of the letters a, b, c, d, e, f, g, h, i and k the cross sections are indicated which are found as well in the timber plan indicated in Figure 4.
As most clearly follows from Figure 3 the surf-board at the stern has been provided with a recess 8 open rearwardly and having side flanks 9 and 10 respectively diverging upwardly and joined at the location of a flat strip 11. This recess can be made as well with a bottom as indicated with the line 8'. The stem generally indicated at 12 has side flanks 13 and 14 as well as a flat front piece 15 which surfaces 13, 14 and 15 in shape fit upon the surfaces 9, 10 and 11. At the location of the surface 11 and the stem 12 velcro fastener belt can be provided.
At 16 a slot has been indicated for the mounting of a centre board.
Accordingly if two or more of the surf-boards shown in Figures 2 and 3 are placed behind each other with the stem 12 in the recess 8 then they closely fit upon each other. This clearly follows from the timber plan of Figure 4 which in the left hand part at the lines 17 and 18 shows how the timber lines a of the stern and g of the stem follow each other whilst this again is shown at the line 18 for the timber lines b of the stern and k respectively of the stem.
The interlocking of the stem 12 in the recess 8 of a stern can be obtained in a simple way by providing the recess upwardly of abutting members e.g. in the form of cams 19, 20 and 21. The interlocking in axial direction then in a simple way can be obtained by means of the pin 22 which can be inserted through an eye 23 of the cam 19 and into the bushing 24 of the stem. Instead of the pin 22 velcro fastener belt can be applied upon the surface 11 or over the seam of the joined stem and stern.
Figures 5, 6 and 7 show a different form of interconnecting at a location of the rear ends of the legs which on both sides of the recess 8 form the stern.
At the front end of the recess stem and stern are interconnected by a pin 25 which will be described further.
At the rear ends the connection is obtained by means of a tension belt 26 most clearly shown in Figure 7.
As Figure 7 shows the belt 26 comprises a left hand part secured to one leg of this stern by means of the connecting strip 27 and a right hand part 28 connected to the right hand portion by means of a connecting strip 29. Both ends are interconnected by means of a tension member 30 of known construction.
The connection by means of the pin 25 is shown more in detail in figures 8 to 10 inclusive.
In Figure 8 31 is a stern and 32 a stem.
Upon the surface indicated with 11 in Figure 8 plate 33 has been mounted shown in Figure 9 which with bent ends 34, 35 lies in one plane with top surface and bottom surface respectively of the stern. Said plate 33 has two bushings or sleeves 36, 37 spaced apart and at the inner side, which means between the outwardly turned surface of the plate 33 and the stern, which stern to this end has been provided with a recess 38 which as shown in Figure 9 and 10 is a little bit larger than the bushings 36, 37.
The stem 32 in the same way has been provided with a plate 39 with bushing 40. Said bushing 40 has a length such that it fits inbetween the bushings 36 and 37.
In Figure 10 the plates 33 and 39 are shown at a distance from each other and on the right hand side of Figure 10 one can see that the plate 33 has a recess or opening 41 through which bushing 40 can penetrate.
If stem and stern are placed against each other as shown in Figure 8 then the bushings 36, 37, and 40 are in line with each other and the pin 25 can be inserted through them.
The connection at the outer ends of the stern, as far as necessary, then can be performed as shown in Figures 5 and 7 inclusive, which means with a tension belt, or in the manner as shown in Figures 2 and 3 by means of the cams 20 and 21. Other combinations of connecting means and other embodiments of connecting means of course are possible.
Figures 11 and 12 show a preferred embodiment according to which the surf-boards 50 at the stern have a recess 51 which is only open at the rear end and the inner form of said recess 51 is such that the stem 52 fits exactly into the recess 51.
The two surf-boards 50 are interconnected by means of a centre board 53 which extends through slots 54 and 55 of top wall and bottom wall respectively of the recess 51 and through the slot 56 of the stern. This centre board 53 can be a centre board which also can be used in the slot 57 of a surf-board 50 when used as mono surf-board.
The invention has been described in its application upon surf-boards. If a body such as a surf-board, the underside of which has the property that with sufficient speed it starts to glide upon the water, is provided with side boards than a vessel shape derived from the surf-board can be formed or a surf-board form derived from a vessel form can be formed, offering more comfort e.g. in that the possibility of a seat is created. Also then the principle upon which the invention is based can be applied.
The Velcro fastener mentioned above is a fastener well known in textile between two faces one having a plurality of loops the other a plurality of elastic hooks.

Claims

1. Multi unit surf-board such as a tandem surf-board formed by at least two mono surf-boards (1, 2) having more than one mast (3, 5) and sail (4, 6), comprising interconnectable parts which can be disconnected, characterized in that each one of said parts is formed by a complete mono surf-board (1, 2) each being formed at its stern and stem respectively such that the stem (12) of a next surf-board (2) by its form fits into the stern of a preceding surf-board (1) and the reverse.

2. Multi unit surf-board as claimed in claim 1, characterized in that said mono surf-boards (1, 2) are identical at stern and stem (12).

3. Multi unit surf-board as claimed in claim 2, characterized in that said mono surf-boards (1, 2) are entirely identical.

4. Multi unit surf-board as claimed in claim 1, 2 or 3, characterized in that the stern of each mono surf-board (1, 2) is provided with a rearwardly open and upwardly widening V-shaped or U-shaped recess (8) into which fits the stem (12) of the next mono surf-board (2).

5. Mono surf-board suitable to be combined to a multi unit surf-board as claimed in one or more of the preceding claims, characterized in that said mono surf-board at the front end (11) of the recess (8) as well as at the stem (12) is provided with connecting members (22, 23, 24) which together form a connection.

6. Mono surf-board as claimed in claim 5, characterized in that said mono surf-board at the rear ends of the legs (9, 10) of the stern present on both sides of the recess (8) is provided with members (20, 21) to lock against upward movement a stem (12) placed in said recess (8).

7. Mono surf-board as claimed in claim 5 or 6, characterized in that the surf-board in its central plane of division at the front side (11) of the recess (8) is provided with a bushing or a plurality of spaced apart bushings (36, 37) in line lying within said plane and parallel to the front part (11) of the recess (8) and that the stem (12) in the same central plane of division and parallel to the line of the stem is provided with a plurality of spaced apart bushings or one bushing (40) respectively, which bushings (36, 37, 40) of stem and stern are adapted with respect to each other such that upon placing stem (12) in the recess (8) of a stern a pin (25) can be inserted through said bushings (36, 37, 40).

8. Mono surf-board as claimed in one or more of the preceding claims 3 to 7 inclusive, characterized in that the stern at the front end (11) of the recess (8) and/or at the rear ends of the legs of said stern is provided with cams (19, 20, 21) extending above the recess and adapted to engage the top surface of a stem (12) placed within the recess.

9. Mono surf-board as claimed in one or more of the claims 5 to 8 inclusive, characterized in that those parts (9, 10, 11, 13, 14) of stem and stern which fit upon each other at least locally are provided with the complementary parts of a Velcro fastener.

10. Mono surf-board as claimed in claim 8, characterized in that one or more of the cams (19, 20, 21) are provided with a vertical bushing (23) for a pin (22) and the stem (12) at the locations which come to lie below the cams (19, 20, 21) are provided with a bushing (24) which bushings are in line if a stem (12) is placed in the recess (8) of a stern.

11. Mono surf-board as claimed in one or more of the preceding claims 5 to 10 inclusive, characterized in that the legs of the stern can be interconnected by means of a tension belt (26) running over the top surface (32) of a stem placed or to be placed in the recess (8).

12. Mono surf-board suitable to be combined to a multi unit surf-board as claimed in claim 1, 2, 3 or 4 and provided with a removable center board (7), characterized in that the surf-board (50) at the stern is provided with a recess (51) which, with the exception of the rearwardly open insert opening is substantially closed and which has an inner form which is equal to the outer form of the stem (52) and that openings are provided in the stem and in top and bottom portion of the stern of a form and location such that in case a stem (52) is placed into the stern opening (51) both surf-boards (50) are interconnectable by a connecting member which can be inserted through the in line lying openings.

13. Mono surf-board as claimed in claim 12, characterized in that the openings are formed by longitudinal slots (54, 55, 56) and the connecting member (53) has the form of a center board.