AU2005202051A1

AU2005202051A1 - Floating Dock Lift

Info

Publication number: AU2005202051A1
Application number: AU2005202051A
Authority: AU
Inventors: Peter Valentine Mogg
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-19
Filing date: 2005-05-13
Publication date: 2005-12-08

Description

FLOATING DOCK LIFT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improvements in boat lifts for elevating boats out of the water when not in use for storage and servicing. More particularly, it concerns a boat lift of the cradle type that is associated with some form of permanent berth.

The docking system of the present invention is a solution for owners of water front residences who wish to keep a boat at a floating dock located at their seaside frontage but have difficulty because the sea state is sometimes too rough to permanently leave a boat in the water attached to a floating dock.

The term boat is herein used in its broad generic sense and includes all sports and recreational vessels and watercraft, powered by engine or sail or un-powered, in general use.

2. Description of the Prior Art Boat lifts are well known in the art for raising watercraft out of the water to protect it from the effects of continued immersion. It is well known that continued exposure to the water ultimately deteriorates the hull of such vessels. Salt water is particularly damaging, but even fresh water storage results in the formation of algae and other deleterious matter on the hull. The ideal maintenance procedure is to completely remove the boat from the water and wash down the hull after every use of the boat and to store it fully out of the water between uses, for example, in a boat shed. It is also advantageous to remove the boat from the water to protect it from damage in adverse weather conditions.

However removing a boat from the water between uses and storing it on land is not convenient or even possible for many recreational boat owners. Owners of water front residences also may wish to have their boat constantly ready to use and choose to leave their boat permanently moored near their residence. Consequently the boat spends the majority of its life merely sitting in the water and constantly deteriorating from the mechanical action of wind, waves, tides and moorings, the chemical action of water, salts and pollutants and the action of marine organisms.

In these situations an alternative either to land storage or to mooring and storing a boat in the water tied to a pier or bulkhead is the boat lift. This is a device for lifting the boat clear of the water at the place where the boat is moored. A large variety of different types of boat lifts have been developed to handle various kinds of boats in different ways and locations. In a broad sense, these may be divided into mobile lifts that can lift and move boats about on land or water and permanent lifts designed to lift boats at a fixed location. The present invention concerns a fixed position boat lift.

In the simplest form of permanent location type boat lift, the boat lift mechanism is mounted directly on the bed of the body of water, generally by means of piers, and a mechanical device, generally a cable winching system, is used to raise or lower the boat. The cables may be attached directly to some portion of the superstructure of the boat, but more typically the cables are connected to a lift cradle that engages of the hull of the boat from its underside. The cradle may be either hoisted vertically or pulled along an inclined ramp or track in and out of the water by cables that are attached to supports positioned above the water. The present invention relates to a vertical hoist cradle boat lift.

Prior art cable hoist cradle boat lifts which may be suitable for use with recreational boats are illustrated by US 4686920 (Thomas) which discloses a boat lift having a motorized cable winch system attached to fixed piers, US 4329082 (Gillis) which discloses a motorized system fixed to a dock and US 3077742 (Brown) which discloses a manually operated system fixed to piers.

A significant concern of a boat owner with a waterfront residence is the issue of convenient access to their boat. The simplest form of wharf or dock is a fixed deck or platform supported above the water by piers. US 3081601 (Fentiman), US 3999397 (Albery) and US 4968182 (Westiwell) all disclose fixed platforms supported above the water by piers which may be suitable for waterfront residences. However fixed docking platforms are inconvenient when boarding or disembarking from the boat because the boat will rarely be at the same level as the platform because of the effect of tides.

This difficulty is overcome by the floating dock. Prior art floating docks which may be suitable for waterfront residences are illustrated by US 4287625 (Dawson), US 4581784 (Rousseau et US 4938629 (Boudrias) and US 5165823 (Cupples).

Both floating docks and boat lifts are advantageous to the boat owner with a waterfront residence, however such residences generally have only limited water space to accommodate both structures and it would be convenient if they could be combined. Such a combination would provide spacesaving, functional, aesthetic and cost benefits.

A known solution is to mount a boat lift on a floating structure. US 3265024 (Kramlich), US 3777691 (Beale), US 5099778 (Palen), US 5655850 (Holmgren), and US 5664513 (Echelbarger), all disclose free floating pontoon docks having boat lift mechanisms which may be suitable for use with recreational boats.

However a known problem with floating boat lifts is that they have poor stability when the boat is raised above water because of the high centre of gravity in that position. The entire system may roll or pitch within the water, especially in rough conditions, carrying with it the potential of the boat sliding from its resting position into the water, and either damaging or sinking the boat.

Furthermore floating docks suffer from the same maintenance issues as boats and it would be advantageous if it could be treated in the same way by removing it from the water between uses or in adverse conditions.

Another known solution is a vertically movable platform which can be raised or lowered to lift the vessel clear of the water. US 3276211 (Drake) discloses a floating platform with piers that may be raised or lowered to contact the sea floor and where the platform can be raised above the water on the piles. The platform has centrally located section that may be displaced relative to the surrounding platform by a mechanical linkage and may be submerged to accept a boat for lifting.

The platform can only be raised above the water in a two step process where the main section is lifted by the linkage against the buoyancy of the central section, the main section is locked to the piles and the central section lifted by the linkage up the main section. Because of this action the platform cannot be raised above the water while carrying a boat.

US 2942425 (De Long et al.) and US 2775869 (Pointer) each also disclose a floating platform with piers that may be raised or lowered to contact the sea floor and where the platform can be raised above the water on the piles. The platform may also be submerged beneath the water so that a boat can be maneuvered above it so that when the platform is again raised the boat is lifted by it above the surface of the water. However to perform the lifting operation the deck of the platform must be completely submerged and the boat access and dock functionality of the platform are lost. While US 2942425 discloses a dual platform, one of the platforms must always be above the other and therefore the upper platform cannot function as an access deck or dock to the boat that is being lifted by the lower platform.

None of the identified prior art documents disclose a system in which the mechanism which lifts the boat on piers also lifts a floating platform but in which the boat lifter and the platform are otherwise independent of each other, and in which the lifted platform still serves as a dock and provides access to the lifted boat.

OBJECTS

A principal object of the invention is the provision of improved boat lifts of the cradle type that are associated with some form of permanent berth.

The docking system of the present invention allows a floating dock and a boat to be raised out of the water in a stowed position, clear of any wave action, and lowered into the water when required.

A walkway provides access to the dock at all times. When in the raised (stowed) position, the dock assumes the functionality of a pier. When in the lowered position, the dock and boat are floating and allow easy access to the boat from the floating dock. The floating dock lift is a solution that will suit many water front owners who currently believe that a pier and boat solution is not practical.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that that detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

SUMMARY OF THE INVENTION The objects are accomplished, in part, in accordance with the invention by the provision of a docking system for lifting a vessel above the surface of a body of water comprising: a plurality of piles fixed to the bed of the body of water; a platform located, and retained, between at least some of the piles and floating on, and having an upper surface located above the surface of, the body of water; frame means located between and supported on, the piles and capable of being raised above and lowered below the surface of the body of water and capable of supporting the vessel above the surface of the body of water; and, the frame and the platform being relatively disposed such that when the frame means lifts the vessel above the surface of the body of water it also lifts the platform above the surface of the body of water.

Accordingly, it is a principal object of the invention to provide a floating dry dock that can be easily adjusted for use with a large selection of different size boats and boat lifts.

It is another object of the invention to provide a floating dry dock that is attractive as well as structurally sound.

It is a further object of the invention to provide a floating dry dock that can be easily and economically manufactured.

Still another object of the invention is to provide a floating dry dock that is easily moved from one location to the next.

These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the invention may be had by reference to the accompanying drawings in which: FIG. 1 is a plan view of a docking system according to the present invention.

FIG. 2 is an elevation view of a docking system according to the present invention in a raised position.

FIG. 3 is an elevation view of a docking system according to the present invention in a lowered position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring in detail to the drawings, in which identical parts are identically marked, the docking system of the present invention comprises a boat lift having piles 1 (usually four but eight for larger lifts) made of concrete or timber, cable winch motors 2 (typically two for small lifts and four for larger lifts), lifter beams 3, boat carrier supports 4, floating dock modules 5, and a suspended walkway 6.

Referring now to the drawings and in particular to Figure 1, the piles are driven into the riverbed or ocean floor 7 and extend above the high water line by a distance of one to two metres. These are placed at each corner of a rectangle. The length of the rectangle is determined by adding the width dimension of the desired boat and the width of the dock plus about one metre to allow for maneuverability. The width of the rectangle is determined by the support necessary for the boat and the desired dimension of the dock. The size and number of piles is determined by the weight of the boat and floating dock modules.

A cable winch motor is an assembly (not shown) of an electric motor, cable winch and cable in the one housing. Cable winch motors are attached near to, or at the top of, the piles and have sufficient aggregate power to lift the boat and floating dock modules. The size, number and arrangement of the cable winch motors are dependent on the weight to be lifted.

Lifter beams are structural beams (usually metallic) with sufficient strength to lift the weight of the boat and floating dock modules. Two beams are placed parallel to each other and are attached, at each end, to the cables hanging down from the cable winch motors.

Boat carrier supports are attached to the top of, and at right angles to, the lifter beams so that a boat is supported in its upright position when the boat is out of the water. The framework of the carrier supports may, but does not necessarily, conform to the general configuration of the hull bottom. Its sole purpose is to support the vessel and, accordingly, there is little limitation to its shape and configuration. It may be entirely rigid or portions may be of flexible sheet or web materials.

Floating dock modules are polyethylene or similar lightweight moldings that, when connected together and placed in water, form a floating platform. One method of holding the dock in position is to anchor the dock to piles by using pile brackets 8. Pile brackets allow the dock to rise and fall with the tide.

A suspended walkway provides access from a fixed structure 9 (such as land or jetty) to the floating dock. The suspended walkway is securely hinged at the fixed structure end while the other end rests on the floating dock allowing the suspended walkway to raise and lower with the dock.

Referring to figures 2 and 3, when the lifting beams are in the raised position (that is, the dock and boat are out of the water) and it is required to use the boat, power is applied to the cable winch motors to cause them to unwind the cable thereby lowering the lifter beams, boat and floating dock into the water to a depth that allows the boat to float free. The floating dock also floats but is held in position by the pile brackets. When the boat is free, the floating dock can be raised by reversing the cable winch motors thereby raising the lifter beams which then raise the floating dock and walkway. When the boat is required back in the stowed position, the lifter beams are lowered back into the water to allow the boat to be positioned over the boat carrier supports. Power is then applied to the winch motors to cause them to wind up the cable thereby raising the lifter beams, boat, floating dock and walkway.

It will be appreciated if the foregoing is presented by way of illustration only, and not by way of any limitation, and that various alternatives and modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention. It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.

Claims

1. A docking system for lifting a vessel above the surface of a body of water comprising: a plurality of piles fixed to the bed of the body of water; a platform located, and retained, between at least some of the piles and floating on, and having an upper surface located above the surface of, the body of water; frame means located between and supported on, the piles and capable of being raised above and lowered below the surface of the body of water and capable of supporting the vessel above the surface of the body of water; and, the frame and the platform being relatively disposed such that when the frame means lifts vessel above the surface of the body of water it also lifts the platform above the surface of the body of water.

2. The docking system of claim 1 wherein the platform comprises at least one floating dock module.

3. The docking system of claim 2 wherein the floating dock modules comprised of polyethylene or similar lightweight moldings that, when connected together and placed in water, form a floating platform.

4. The docking system of claim 3 wherein the floating dock modules are anchored to the piles by brackets that allow the them to rise and fall with the tide. The docking system of claim 4 further comprising a walkway to provide access from a fixed structure such as land or a jetty to the floating platform, the walkway being hinged at the fixed structure end while the other end rests on the floating platform allowing the walkway to follow the movement of the platform.

6. The docking system of claim 1 wherein the piles are placed in the shape of a rectangle.

7. The docking system of claim 6 wherein the width of the rectangle is greater than the combined width of the vessel to be lifted and the width of the platform.

8. The docking system of claim 7 wherein the piles extend above the high water line of the body of water.

9. The docking system of claim 1 wherein the frame comprises parallel lifter beams and boat carrier supports attached to the top of, and at right angles, to the lifter beams so that the vessel is supported in its upright position when it is lifted out of the water. The docking system of claim 9 wherein lifter beams are attached at each of their ends to cables wound by cable winch motors attached near to, or at the top of, the piles.

11. The docking system of claim 10 wherein the cable winch motor is an assembly of an electric motor, cable winch and cable in the one housing.

13. A docking system for lifting a vessel above the surface of a body of water comprising: a plurality of piles fixed to the bed of the body of water, wherein the piles are placed in the shape of a rectangle, the width of the rectangle is greater than the combined width of the vessel to be lifted and the width of the platform, and the piles extend above the high water line of the body of water; a platform located, and retained, between at least some of the piles and floating on, and having an upper surface located above the surface of, the body of water, wherein the platform comprises at least one floating dock module, the floating dock modules comprised of polyethylene or similar lightweight moldings that, when connected together and placed in water, form a floating platform, and the floating dock modules are anchored to the piles by brackets that allow the them to rise and fall with the tide; a walkway to provide access from a fixed structure such as land or a jetty to the floating platform, the walkway being hinged at the fixed structure end while the other end rests on the floating dock allowing the walkway to follow the movement of the platform; frame means located between and supported on, the piles and capable of being raised above and lowered blow the surface of the body of water and capable of supporting the vessel above the surface of the body of water, wherein the frame comprises parallel lifter beams and boat carrier supports attached to the top of, and at right angles to, the lifter beams so that the vessel is supported in its upright position when it is lifted out of the water, the lifter beams are attached at each of their ends to cables wound by cable winch motors attached near to, or at the top of, the piles, and the cable winch motor is an assembly of an electric motor, cable winch and cable in the one housing; and, the frame and the platform being relatively disposed such that when the frame means lifts vessel above the surface of the body of water it also lifts the platform above the surface of the body of water.