F L O A T I N G D O C K. The invention relates to a floating dock consisting of a lift platform with upright posts at the long sides of the platform, wherein the dock's float bodies are supported on pivotable brace members and disposed externally of the dock and the dock's platform can be raised and lowered in relation to the float bodies.
This type of floating dock is intended especially for smaller vessels, where the floating dock should be mobile and easy to operate. A number of floating docks intended for this purpose are known in the prior art. US Patent 3,412,702, for instance, describes a floating dock wherein elongated float bodies supported by brace members are arranged at the long sides of the dock, the float members being attached to upright beams or posts on a platform. By pivoting the float bodies about hinges, it is possible to raise and lower the platform. This construction, however, is relatively complicated, and the float bodies are raised and lowered by means of a winch with lines extending out to the float bodies. This assembly is not reliable in operation, because if the locking mechanism on the winch slips or releases, the platform will very quickly fall down to a submersed position. Moreover, it is not possible to adjust the height of the two float bodies in relation to each other.
US Patent 3,415,212 describes an assembly with separately adjustable float bodies, but this is a rather large construction in which cylinders force the float bodies to pivot while in the water. This assembly is complicated and not suitable for use as a small, simple drydock.
A simpler type of floating dock is described in US Patent 3,265,024, wherein a platform that can be raised and lowered is secured between two float bodies, it being possible to raise and lower the platform between the float bodies without moving the floats. In this assembly, too, however, the system of support lines between platform and floats is relatively complicated, and it is easy for the dock to assume
an unstable position when the platform is being raised and lowered.
Further examples of floating docks are disclosed in German Patent 256,373, which describes one embodiment wherein both the dock itself and the float bodies at the sides can be filled with and emptied of water, obtaining an alternating effect between these two members.
The object of the invention is to obtain a floating dock which is as simple and robust as possible, while at the same time it can be controlled, i.e., raised and lowered, by simple mechanisms and is also as stable as possible in the lateral direction.
These aims are achieved with an assembly that is characterized by the features recited in the appurtenant patent claims.
The assembly of the invention will be described in greater detail in the following with reference to the accompanying drawings, wherein:
Figure 1 shows a floating dock in accordance with the invention, seen from one end, and Figure 2 shows the floating dock of the invention as seen from above.
The lifting pontoons 1 for the floating dock of the invention are made as tubular, elongated bodies and are disposed along the two long, sides of the floating dock. The work deck of the floating dock is designated by numeral 3. At the sides of the floating dock, upright columns or posts 2 are provided, preferably two on each side.
The lifting pontoons or float bodies 1 are connected to the floating dock by a swivel link which preferably is attached to the upright posts. Between the swivel link and a point higher up on the post, hydraulic cylinders are attached,
which are intended to guide the float bodies between the two positions indicated in Figure 1 with solid and broken lines. The hydraulic drive means can be arranged within the post itself, which preferably is formed as a hollow cylinder, or on a raised work platform arranged between two posts. The person using the floating dock can stand on the raised work platform and control the movements of the floating dock, raising or lowering the dock in the water.
Stabilizer tanks 4 are provided underneath the work platform, extending transversely of the work deck and giving the work platform or floating dock a buoyancy that approximately equalizes the platform's weight. This permits the float bodies to support the weight of the boat that is placed on the platform.
A floating dock of this type can be used in connection with docking of ships and smaller vessels, or for raising and lowering other equipment in a maritime environment.
Compared to conventional floating docks, the assembly of the invention has the following advantages:
a) The platform can be raised and lowered rapidly at the desired rate of speed, for example, as quickly as 20 seconds. b) No interior maintenance is required, since all pipes and pontoons are hermetically welded and sealed and may optionally be filled with polyurethane foam or the like. in that case, buoyancy will not be lost if the pipes or pontoons become punctured owing to a collision or corrosion damage. c) Since the pontoons are positioned externally of the platform, unusually good stability is obtained, especially during raising and lowering of the platform, d) The dock does not require a piping system for filling/ emptying the tanks during operation.
e) The dock can raise itself, thus permitting exterior cleaning and maintenance to be performed easily. For example, the platform can be moved into shallow water, where it can then be raised up above the ground and "stand" on the float bodies, thereby providing access to the underside of the platform for maintenance. f) The movement of the float bodies can be undertaken independently on the two sides of the platform, permitting one to compensate for imbalance caused by the object placed on the platform. Independent adjustment of the float bodies also allows one to counteract heavy seas running against one side of the platform.
The platform is especially intended for use in connection with pleasure craft and smaller fishing boats.
With the floating dock of the invention, a small floating dock is provided which can be operated rapidly, which is highly stable and which may easily be transported to the desired site for use. The platform can also be used for transporting objects over shorter distances at sea.