Gangplank or Ladder for Watercraft Made Up of Several Articulated Sections

The invention relates to a gangplank or ladder for watercraft comprising at least two portions hinged together to take up a folded position and an open position respectively, the first of said portions being hinged to the craft.

A gangplank-ladder of this type is described for example in the Italian industrial utility model application No. 4225 B/86. The two portions of the gangplank described in this previous patent are hinged together by means of a pair of triangular plates to which pairs of actuators in the form of cylinder-pistons are fastened, hinged at one end to the said plate and at the opposite end to one or the other of the two portions of the gangplank. This configuration is particularly complex and cumbersome and, in addition, requires very many connections to the hydraulic system for controlling the actuators.

The first portion, that is the upper portion of the gangplank, is hinged to the craft and its oscillation with respect to the hull is obtained by means of a cylinder-piston system connected to the gangplank by means of a system of levers. This type of control also is complex and very cumbersome.

One aim of the present invention is to realize a ladder or gangplank of the mentioned type, in which the connection to the craft and the control of the oscillation with respect to the latter is brought about in a more efficient and simpler manner, with a reduction of the actuator members.

This aim is achieved, according to the invention, by foreseeing the first portion of the gangplank, that is the upper portion, rotating with respect to the craft around an axis coinciding with a rotating outlet axis of an actuator preset to operate the rotation of said first portion with respect to the hull of the craft. In this way the need for any type of transmission or leverage is eliminated. The actuator used may be any type of actuator which has a rotating outlet shaft and a sufficient torque to manoeuvre the whole gangplank. For example, a hydraulic motor may be used.

According to an improvement of the gangplank of the present invention, a further aim is achieved, which is that of realizing a gangplank in which the reciprocal articulation of the two or more portions it consists of and the opening and closing control of said portions takes place in a more efficient, simpler and less cumbersome manner.

This can be obtained, for example, with a gangplank of the described type, comprising at least one rotating blade actuator forming an active hinge between two consecutive portions of the gangplank.

On the other hand, a system may also be foreseen with a cylinder-piston actuator associated with the bridgeboard of the gangplank and connected by means of a system of drag cables to pulleys fastened to the portions of the gangplank.

Further advantageous embodiments of the gangplank according to the invention are shown in the appended dependent claims.

The invention will be more easily understood by following the description and the appended drawings, which show a practical, non restrictive embodiment of the present invention. In the drawing:

FIGS 1 and 2 show in diagrammatic form a gangplank according to the invention in a folded position and extended position respectively;

FIG. 3 shows a gangplank according to the invention in the position for use;

FIGS. 4, 5 and 6 show a folding ladder with three sections, re-entering within the railing of the craft;

FIG. 7 shows an axial section of the hinge of the gangplank or ladder according to the invention, taken along the line VII--VII in FIG. 8;

FIG. 8 shows a transverse section of the hinge in FIG. 7, taken along the line VIII--VIII in FIG. 7;

FIG. 9 shows an external view taken along the line IX--IX in FIG. 8;

FIGS. 10 and 11 show a detail of a modified embodiment, in which FIG. 10 is a section taken along line X--X in FIG. 11 and FIG. 11 is a view taken along line XI--XI in FIG. 10.

The Figures from 1 to 6, in which the same reference numerals are used to show equal or similar parts, show a ladder or gangplank for watercrafts in diagrammatic form, realized with a hinge according to the invention. FIGS. 1 and 2 show a ladder 1 in two portions 1A and 1B, hinged together at 3 and connected, by means of a high torque actuator 7, to the hull or a craft. The portions 1A, 1B can take up a folded position, in which they are moved close together, as shown in FIG. 1, and an extended position (FIG. 2) for use.

FIG. 3 shows a gangplank 1 in the position for use, also realized in two portions 1A and 1B hinged together at 3 and connected by means of an actuator 7 to the hull of the craft 9. The gangplank shown in FIG. 3 could be the same ladder shown in FIGS. 1 and 2, which carries out the double function of ladder and gangplank.

The ladder in the Figures from 4 and 6 has three sections 1A, 1B, 1C articulated together; the first section 1A is articulated to the hull of the craft also and makes up part of the rail P within which the ladder 1 re-enters when in the folded position (FIG. 4).

The upper portion 1A of the ladder or gangplank in the Figures from 1 to 6 is hinged to the hull of the craft around an axis which coincides with the outlet axis 7A of the actuator 7, which can be a hydraulic motor or another suitable actuator with sufficient torque. In this way a control system is obtained which is extremely compact and has no leverages or transmissions of any type.

As shown in diagrammatic form in the Figures from 1 to 6, the portions 1A, 1B and 1C of the ladder or of the gangplank are connected to each other by means of a pair of hinges 11 (one for each bridgeboard of the gangplank or ladder), which will be described in greater detail below with reference to the Figures from 7 to 9.

In practice, each hinge 11 forms at the same time an actuator for controlling the relative rotation of the two portions 1A, 1B or 1B, 1C. As shown in detail in the Figures from 7 to 9, with reference for example to the portions 1A and 1B, each hinge 11 is made up of a case forming a body 15 and of a disc-shaped lid 17 fastened to the body 15 by means of screws 19. Inside the body 15 there is a substantially annular chamber 21 with a radial division 23 (FIG. 7). Inside the annular chamber 21 a blade 25 is positioned integral with a sleeve 27, which is in turn fastened by means of a tab 29 to a pin 31. The blade 25 and the radial division 23 divide the annular chamber 21 into two compartments with variable volume. When the blade 25 rotates around the axis of the pin 31, one of the two compartments increases and the other decreases. Two ducts 33, 35 for the inlet of a fluid under pressure open into the two compartments of the annular chamber defined by the blade 25 and the radial division 23. The letting in of the fluid under pressure into one or the other of the two compartments causes the blade 25 to rotate in one direction or the other. In fact, the hinge 11 is formed by a rotating hydraulic (or pneumatic) actuator.

One of the two portions 1A, 1B of the gangplank or ladder 1, portion 1A in the illustrated example, is made integral with a disc-shaped lid 17 and the body 15 by means of the same screws 19 which fasten the two portions 17 and 15 together. The other portion (portion 1B in the illustrated example) is fastened by means of screws 36 to a flange 37 integral with the pin 31. Therefore a relative rotation between the blade 25 and the body 15, 17 of the actuator causes a relative rotation of the portions 1A, 1B of the gangplank. It is clear that two active hinges, that is ones realized with an actuator of the type illustrated in the Figures from 7 to 9, can be interposed between two consecutive portions of the gangplank, but it is also possible to foresee a passive hinge, that is one without an actuator, and an active hinge.

FIGS. 10 and 11 show an embodiment with a different system for the control of the reciprocal rotation of the portions 1A, 1B. In said Figures, the portions of the gangplank 1A and 1B are represented by one of the bridgeboards of the portions 1A and 1B. Said portions are reciprocally hinged at 50. A pulley or sheave 52, which rotates integrally with portion 1B around the axis of the pin 50 with respect to portion 1A, is fastened integrally with the portion 1B. A cable 54 winds around the pulley 52, one of its ends, shown with 54A, being fastened to one end 56A or a rod 56 of a cylinder-piston system 58. The other end of the cable 54, shown with 54B, is fastened to the other end 56B of the rod 56. The cylinder-piston system 58 is fastened at 60 to the portion 1A of the gangplank. The cable 54 winds, as well as around the pulley 52, around a pair of further pulleys 62, 64 also, of small diameter and idle-mounted on the respective pins 63, 64 fastened to the portion 1A of the gangplank. An anchoring means 66 fastens the cable 54 to the pulley 52 and to the portion 1B of the gangplank.

When the rod 56 moves along the cylinder of the cylinder-piston system 58, through the effect of the control fluid, the cable 54 moves, causing the pulley 52 (and therefore the portion 1B of the gangplank) to rotate around the axis 50. In this way the control of the two portions 1A, 1B with the portion 1B turning over onto the portion 1A, is obtained. The entire control system can be housed in the bridgeboards of the gangplank or ladder, taking up the minimum amount of space. In addition, in this case also one single actuator can be foreseen on one bridgeboard of the ladder, or two actuators arranged symmetrically on the two bridgeboards, with respective control cables 54.

In the case of the three-section ladder in the Figures from 4 to 6, another pulley 52 will be foreseen on the hinging axis of the sections 1B and 1C, integral with section 1C, on which a cable is wound and fastened, passing also on the other pulley 52, shown in Figures 10 and 11, which can possibly be an extension of the cable 54 illustrated there.

It is understood that the drawing shows an example only, which is given merely as a practical illustration of the invention, and that the invention can vary in forms and arrangements without going beyond the protection limits of the following claims.