Support arrangement for boats
The present invention relates to a support arrangement for boats that is intended to automatically hold the boat in the correct position during storage or transport and in connection with winching onto or off from a cradle for boats, and in which one or more support arrangements according to the invention is included. The support arrangement according to the invention is especially suitable to constitute the rear section of a boat cradle fitted to a trailer, whereby it above all facilitates taking up a boat from the water onto the trailer and allows pulling up and launching without the risk that the boat becomes askew on the trailer or is damaged in some other way. The support arrangement displays a reliable function despite its simple construction design and few moving parts.
A support arrangement with a self-adjusting side roller in a boat trailer to make it possible for a single person to easily pull up a boat from the water onto a trailer and vice versa has previously been proposed through the Swedish document (C2) 508 621. When the keel of the boat presses against a keel roller, side rollers at the ends of support arms pivot through the intermediary action of a pivoting device and at the same time press tubular casings along the axis of the keel roller into the keel roller. The movement of the supporting arms on both sides is synchronised with a synchronisation device, whereby the support arms always take up the same angle in relation to the chassis of the trailer.
The present invention constitutes an improvement due, among other things, to the fact that neither a keel roller with axially displaceable casings nor any synchronisation device are required for reliable function. Further advantages of the support arrangement according to the present invention constitute that instead of having only one keel roller, the support arrangement is provided with at least two rollers intended to support a boat in connection with and on either side of the keel or the centre line of the boat, whereby the weight of the boat is distributed over at least four rollers. In addition, according to the invention, these rollers, like those known previously, are arranged on pivoting arms that through the weight of the boat can swing upwards so that the side rollers arranged at the opposite ends of the pivoting arms abut and can roll against the side of the hull of the boat. Furthermore, according to the invention, the pivoting arms are supported by the chassis to pivot so that they can rotate around an axis that is essentially arranged in the longitudinal direction of the non-loaded pivoting arms, i.e. in the latitudinal direction of the boat, which means that all the rollers on the pivoting arm abut a boat keel, even when off-loading and loading the boat, when the longitudinal axis of the keel of the boat has a significant and varying angle in relation to the longitudinal direction of the trailer of the cradle of the boat. In
this way, off-loading and loading is made easier through improved guiding of the hull by the abutting rollers, and in addition, the wear and stress on the hull and winching device is reduced.
The invention is described in greater detail below with reference to the enclosed drawings where Fig. 1 shows in a somewhat simplified manner and from behind an unloaded trailer with a support arrangement according to the invention, Fig. 2 shows an arrangement according to Fig. 1 with a boat supported by the support arrangement, Fig. 3 shows a trailer with a support arrangement according to the invention seen from above and Fig. 4 shows a perspective view of the support arrangement according to the invention. A boat trailer according to the figures is, in a known manner, built up of a chassis 1 with longitudinal beams 2, 3 that are supported by a wheel axle 4 with wheels 5, 6. Also in a known manner, the chassis is equipped with support rollers 7 and 8A, 8B, 8C, 8D for supporting a boat, as well as a winch device 9 at the front end of the trailer for off-loading and loading. A support arrangement 10 according to the invention is supported by the chassis at the rear end of the trailer.
The support arrangement 10 is supported by the chassis through the cross-beam 11. A right support arm 20 and a left support arm 30 are arranged symmetrically in relation to the longitudinal axis of the trailer on cross-beam 11. Both support arms 20 and 30 are mounted to pivot with the cross-beam 11 via rotating axles 21 and 31 respectively and arranged in the latitudinal direction of the cross-beam, through which the outer parts 22 and 32 respectively of the supporting arms can swing upwards from the cross-beam 11 at the same time as the inner parts 23 and 33 respectively of the supporting arms swing downwards. To allow this, the inner parts 23 and 33 of the supporting arms are divided into two inner branch arm sections 24, 25 and 34, 35 respectively in a fork-like manner, and where the inner front branched arm sections 24 and 34 are shorter than the inner rear branched arm sections 25 and 35. The outer parts 22, 32 and the inner branched arms 24, 25, 34, 35 end in axles on which outer support rollers 26A, 36A respectively inner support rollers 26B, 26C, 36B, 36C are arranged to rotate.
As is most evident from Fig. 4, the ends of the cross-beam 11 are mounted to pivot in the side beams 2 and 3 thought bearings 12 and 13 respectively. In this way, the whole of the support arrangement 10 can pivot around an axis in the latitudinal direction of the chassis so that at least the four inner guiding rollers 26B, 26C, 36B, 36C abut the hull 14 of a boat during loading and off-loading. For example, when loading a boat, its bow is moved with the help of the winch device 9 towards the support arrangement 10 with its support
rollers, whereby the support arrangement 10 initially adjusts itself by the cross-beam 11 pivoting until the inner support rollers abut the hull on either side of the bow. When the boat hull presses against the inner rollers due to the effect of the winch or the weight of the boat, they will be pressed so that the support arms 20 and 30 pivot around the rotating axles 21 and 31 and the outer guiding rollers 26 A and 36A swing in towards the hull with the maximum swing being limited by the design of the support arms. When the bow of the boat has been pulled up some way and the hull at the support arrangement widened, the outer guiding rollers 26 A and 36A will abut and roll along the sides of the hull.
A support arrangement 10 according to the invention for boats on trailers and similar thus has two pivoting support arms 20, 30 on which outer support rollers 26 A and 36A are mounted to rotate, whereby the support arms 20, 30 are so arranged that they swing up so that the outer support rollers 26 A and 36A move towards the sides of a boat hull 14 when the inner parts of the support arms are put under loading by the weight of the boat. Each support arm 20, 30 is equipped with at least one outer support roller 26A, 36A and at least two inner support rollers 26B, 26C, 36B, 36C, support arms 20, 30 are each joined to pivot with a crossbeam 11 around axles 21, 31, essentially parallel with the longitudinal direction of the boat hull 14, and the inner support rollers 26B, 26C, 36B, 36C of the supporting arms are arranged on a fork-shaped part 23, 33 of the respective support arm that extends from the point of pivoting and allows the inner support rollers 26B, 26C, 36B, 36C to be arranged in front of or respectively behind the cross-beam 11 and that the support arms rotate so that the outer support rollers 26 A, 36A swing up towards the sides of the boat hull 14 when the inner support rollers 26B, 26C, 36B, 36C are pressed down by a boat. In addition, the support arms 20, 30 can pivot in the latitudinal direction of the boat to allow all of the inner support rollers 26B, 26C, 36B, 36C to abut the hull during essentially the whole loading or off-loading manoeuvre. The support arrangement 10 preferably constitutes the rear part that is intended to support a boat hull on a trailer, but it can also be utilised stationary for storage as a boat cradle. In addition, at least one forward support arrangement according to the invention be utilised for a boat cradle or trailer.
According to a preferred embodiment, the interval between the inner support rollers 26B and 36B respectively 26C and 36C for opposing support arms is adapted to allow the inner support rollers to abut a boat hull 14 on either side of the keel or the centre line of the hull.
It is preferable that the pivoting connections 21, 31 of the supporting arms 20, 30 with the cross-beam 11 are arranged closer to the inner support rollers 26B, 26C, 36B, 36C
so that the weight of the outer support roller 26A respectively 36A counter-balances the weight of the inner support rollers and holds the outer support rollers in a lower position when the support arrangement 10 is not subject to loading. The fork shaped parts 23, 33 of the supporting arms 20 respectively 30 that support the inner front 26B, 36B and rear 26C, 36C support rollers are preferably asymmetric so that the inner rear 26C and 36C support rollers are further away from the cross-beam 11 than the inner front support rollers 26B and 36B. As is evident from the embodiment shown, the supporting arms 20, 30 can pivot around an axle in the latitudinal direction of the boat through the ends of the cross-beam 11 being mounted to pivot 12, 13 with the chassis 1, 2, 3. In an alternative embodiment (not shown), the supporting arms 20, 30 can pivot individually around axles in the latitudinal direction of the boat through a pivoting mounting in the cross-beam, for example, through a universal joint suspension at the axles 21 and 31.
The present invention is not limited to that described above and shown in the drawings but can be changed and modified in a number of ways within the scope of the concept of the invention as stated in the following claims.