GB2372495A

GB2372495A - Lifting apparatus for small water craft

Info

Publication number: GB2372495A
Application number: GB0200699A
Authority: GB
Inventors: Albert Michael Sanderson
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-01-12
Filing date: 2002-01-14
Publication date: 2002-08-28
Also published as: GB0200699D0; GB0100881D0

Abstract

Lifting apparatus 10 comprising a mounting plate 12 to secure the apparatus to part of the body adjacent to a bathing platform 13 on a water borne vessel, and a craft support assembly 14 upon which a small water craft is releasably mounted. The mounting plate 12 is linked to the craft support assembly 14 by an articulated linkage 16 which enables the craft apparatus to be raised or lowered relative to the bathing platform of the vessel. The craft support assembly is also movable laterally of the linkage to allow stowing or launching of the craft. This allows unobstructed use of the bathing platform even when the craft is being stored.

Description

LIFTING APPARATUS This invention relates to a lifting apparatus particularly but not exclusively for lifting a small water craft off and onto a water borne vessel.

It is common for water borne vessels to have provision for lifting of small water crafts such as, for example a rigid inflatable boat (RIB) or a jet ski, off and onto the vessel for recreational or emergency use.

Thus, on a conventional vessel, a crane or passerelle is usually mounted on a bathing platform or transom of the vessel and is operable to lower a small water craft into the water or to raise the craft from the water for stowing. The use of a crane or passerelle mounted in this way is necessary because the bathing platform is too long to allow the use of conventional davits mounted high on the transom of the vessel. When stowed on the bathing platform, the small craft is retained by chocks which are secured directly to the bathing platform.

It will be realised that the stowing of the craft on the bathing platform, and the provision of a crane or passerelle on the same platform provides a significant obstruction to the use of this platform for its intended purpose, i. e. recreational use and boarding of the vessel when alongside a floating pontoon. This is particularly apparent when it is realised that most vessels of this kind have a bathing platform of between 0. 5-4. 0m in depth and 2-8m in width.

A further problem exists with the above mentioned arrangement

insofar as the use of a crane or passerelle secured to the bathing platform or transom, which is usually a relatively weak part of the vessels superstructure, renders it necessary to reinforce the bathing platform to ensure that it can withstand the forces exerted on it when the crane or passerelle is operated. This reinforcement results in an increase in the cost of manufacture of the vessel with an associated increase in cost to the end user.

The object of the present invention is to overcome or at least minimise the above mentioned problems associated with the conventional arrangements.

Thus and in accordance with the present invention therefore there is provided a lifting apparatus comprising a mounting part to secure said apparatus to a part of a water borne vessel adjacent a bathing platform thereof and a craft support part on which a small water craft can be releaseably mounted, said craft support part being linked to said mounting part by a linkage and being movable relative to said mounting part between a first position in wich said craft can be launched and a second position, in which, said craft support part is movable between a position in which said support frame is disposed spaced from said bathing platform and a position in which said craft support part is disposed at least partially on or over said bathing platform.

With this arrangement it is possible to provide a lifting apparatus

which avoids unnecessary obstruction of recreational areas of a vessel, particularly when the vessel is not under way and furthermore reduces the need for expensive reinforcement of such areas.

The invention will now be described further by way of example only and with reference to the accompanying drawings, in which: Figures 1a and 1b show a diagrammatic side view, of one form of lifting apparatus in accordance with the present invention, the apparatus being shown in two positions, a first stowing position and a second launching position; Figure 2 shows a diagrammatic plan view from underneath the vessel of the lifting apparatus of Figure 1 in the launching position, and Figures 3a and 3b show side views, partly in section, of alternative forms of means for securing of the craft support assembly when in the stowed position relative to the vessel.

Referring now to the drawings, there is shown in Figures 1 a and 1 b, one form of lifting apparatus 10 according to the present invention shown mounted on a vessel 11. The lifting apparatus 10 is shown in two positions ; a second position (in Figure 1a) and a first position (in Figure 1b) as will be hereinafter described.

The lifting apparatus 10 comprises mounting plates 12 which are secured to the vessel hull adjacent the bathing platform 13. The vessel hull

is usually considerably stronger than the bathing platform 13 and therefore is able to resist the forces it will experience as the assembly 10 is operated. The mounting plates 12 are connected to a craft support assembly 14 by an articulated assembly 16, the articulated assembly 16 allowing the craft support assembly 14 to be moved between a second position in which the assembly 14 can be stowed at least partly on the bathing platform, and a first position in which the craft support assembly 14 is adjacent, or in, the water whereby the small craft can be launched.

The mounting plates 12 are fixedly secured to the vessel hull.

The craft support assembly 14 is of any suitable form to provide a secure and stable mounting for a small watercraft (not shown) For this purpose, the assembly may include craft support members (not shown) with which the vessel engages when supported and the vessel may be secured to the craft support assembly, for example by straps.

The articulated assembly 16 comprises a pair of lever members 17, a supporting lever frame 18, a top frame 19 and optionally a pair of stiffening members 21.

Each of the pair of lever members 17 is pivotally attached to a respective one of the mounting plates 12 at one end and pivotally attached to opposite sides of the top frame 19 at the other end. The supporting lever frame 18 is also pivotally attached to respective ones of the mounting plates 12 at respective ends of respective arms 22, whilst upstanding members 23

of the frame are pivotally attached to opposite sides of top frame 19. Respective ones of the pair of stiffening members 21, if provided, are pivotally attached to respective ones of the mounting plates 12 and at the other end are pivotally attached to opposite ends of the top frame 19.

The top frame 19 has mounted thereon, at least one guiding device for example two pairs of rollers 24 between which is disposed the craft support assembly 14. Mounted in this way, it will be appreciated that the craft support assembly 14 can move laterally relative to the top frame 19 by sliding through the rollers 24.

In the embodiment shown, a hydraulic driving connection 26 is connected between a bearing block 27 fixed to the mounting plates 12 or directly to the vessel and a transverse member 28 of the support frame 18 to effect movement of the apparatus and the hydraulic connection 26 is linked to a hydraulic pump (not shown) disposed on the vessel. Whilst in the embodiment described, a hydraulic drive arrangement is shown, it will be appreciated that any suitable driving connection, whether manual or automatic, can be utilised to effect the above mentioned movement.

Means is also provided such that once the apparatus 10 is in the second position and the craft support assembly has been moved at least partly onto the bathing platform, the assembly 14 can be secured in position relative to the bathing platform 13 by, for example the provision of projecting flanges 29 on one or both sides of the craft support assembly

which engage under generally Lever retaining chocks 31 mounted on the bathing platform as shown in Figure 3a. Additionally, if required, a second pair of projecting flanges 32 as shown in Figure 3B, may be provided on one of both sides of the craft support assembly 14 which can engage a Lever chock 33 and can be retained in position by a screw threaded fastener 34 which can be tightened into contact with the flange 32 to retain it in position.

In use, the lifting apparatus 10 is mounted on the vessel as described above. When mounted, the craft support assembly 14 is slidably received between the rollers 24 on the top frame 19. A small water borne craft is mounted on the craft support assembly 14 and is, for example held on wooden support blocks by securing straps (not shown). When the apparatus 10 is in the second position (shown in Figure 1a), the craft support assembly 14 can be moved between the positions shown in full lines and dotted lines in the Figure by sliding laterally relative to the top frame 19 through the rollers 24. When the craft support assembly is in the position shown in dotted lines, as mentioned above, the assembly can be releaseably secured to the bathing platform. This is the position which is utilised when the vessel is in motion.

In this second position, it will be appreciated that the vast majority of the weight of the apparatus and any small water craft or other weight mounted upon it is borne both by the vessel superstructure to which the

mounting plates 12 are attached and the bathing platform 13.

When the vessel is stationary at anchor or moored up and use of the bathing platform for recreational access to the water or other purposes is desired or when it is desired to launch the small water craft, assembly is released from the securing device or devices shown in Figures 3A and 3B and slid relative to the top frame 19 to the position shown in full lines in Figure 1 a until the craft support assembly 14 is clear of the bathing platform and over the water. If it is desired to launch or retrieve the small water craft the hydraulic drive connection 26 or other driving mechanism is then actuated which causes the supporting lever frame 18 and the lever members 17 to be driven downwardly causing the craft support assembly 14 to move radially downwardly towards the water. In particular, the supporting lever frame 18 and lever members 17 pivot about the connections with the respective mounting plates 12. Furthermore, the other ends of the lever members 17 and the upstanding members 23 of the support frame 18 are pivotally connected to the top frame 19 and therefore the top frame 19, upon which the craft support assembly 14 is mounted, pivots relative to the lever members 17 and the support frame 18.

Thus, as the supporting lever frame 18 is driven, the assembly moves into the position shown in Figure lb thereby lowering the craft support assembly 14 towards the water. Eventually, the craft support assembly 14 will reach a position where the small water craft or vessel can be launched

from the craft support assembly 14 and in such a position the craft support assembly 14 may be underneath the surface of the water.

It will be realised that with the arrangement of the present invention, it is possible to maintain the orientation of the craft support assembly 14 whilst the assembly is moved towards the water on launching. This is because the lever members 17 and the supporting lever frame 18 are pivotally connected to the top frame 19 thereby allowing the assembly to be retained in a generally horizontal position until the craft is launched.

Stowing of the craft or vessel is the reverse of the above operation insofar as the hydraulic drive connection 26 is driven in the reverse direction thereby raising the apparatus, and hence the craft support assembly 14, until it reaches a position adjacent the bathing platform 13. Once in this position, the craft support assembly can be slid into a position on the bathing platform through the rollers 24. Once in this position, the craft support assembly 14 can be secured in position as described above. If it is desired to use the bathing platform whilst the vessel is stationary, the craft support assembly 14 can be slid off the rollers 24 until it is in the second position (shown in full lines in Fig. 1 a). In this position it will be appreciated that the bathing platform is free for any use.

The stiffening members 21, if provided, act as additional stiffeners for the articulated assembly 16 and improve the angular stability of the craft support assembly 14 and the support 18 thereby helping to assist in maintaining the craft support assembly 14 substantially horizontal even when passing through the position where pivoting points of both ends of levers 17 and frame 18 are in line and there is any looseness in the pivotal connections between the lever members 17 and the supporting lever frame 18 and the craft support assembly 14.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.

Claims

CLAIMS 1. Lifting apparatus comprising a mounting part to secure said apparatus to a part of a water borne vessel adjacent a bathing platform thereof and a craft support part on which a small water craft can be releasably mounted, said craft support part being linked to said mounting part by a linkage and being movable relative to said mounting part between a first position in which said craft can be launched and a second position, in which, said craft support part is movable between a position in which said support frame is disposed spaced from said bathing platform and a position in which said craft support part is disposed at least partially on or over said bathing platform.
2. Lifting apparatus according to Claim 1 wherein said movement of said craft support part between said first and second position is effected by a drive mechanism.
3. Lifting apparatus according to Claim 2 wherein the drive mechanism is a hydraulic drive mechanism.
4. Lifting apparatus according to any one of Claims 1 to 3 wherein said linkage comprise an articulated assembly of members which are pivotably attached to said craft support part at one end and to said mounting part at an other end.
5. Lifting apparatus according to Claim 4 where said articulated

assembly of members comprises a pair of lever members, and a support frame, both of which are pivotably attached to said mounting part at one end and which are pivotably attached to a top frame upon which a craft support assembly is moveably mounted.
6. Lifting apparatus according to Claim 5 wherein the articulated assembly of members further comprise a pair of stiffening members which are pivotally attached to the mounting part at one end and to said top frame at the other end.
7. Lifting apparatus according to Claim 5 to Claim 6 wherein the top frame comprises at least one guiding device which allows guided lateral movement of said craft support assembly between positions in which said support part is disposed spaced from the bathing platform and a position in which said part is disposed at least partially on or over said platform.
8. Lifting apparatus according to any one of Claims 1 to 7 wherein locking means is provided, wherein when said craft support part is disposed at least partially on or over the platform, the locking means is operable to secure said part in position relative to the platform.
9. Lifting apparatus substantially as hereinafter described with reference to the accompanying drawings.