GB2024734A

GB2024734A - A cargo loading and unloading assembly for ships

Info

Publication number: GB2024734A
Application number: GB7923294A
Authority: GB
Original assignee: Kvaerner Brug AS
Current assignee: Kvaerner Brug AS
Priority date: 1978-07-04
Filing date: 1979-07-04
Publication date: 1980-01-16
Also published as: IT1118871B; IT7949608A0; NO142030B; NO782327L; BR7904210A; DE2926465A1; NO142030C; GB2024734B; JPS5535791A

Abstract

A cargo loading and unloading ramps for ships, of the type comprising at least two sections 6, 8 which are hinged together and to the ship 1 about horizontal axes 9, 7 and which extend fore-and-aft of the ship. The connection between the ramp sections comprises two elements 13 positioned on opposite sides of the ramp and adapted to assist in the adjustment of the angle between the planes of the two ramp sections 6, 8. In order to reduce energy consumption and simplify the construction and control of the ramp assembly, each connection element 13 is generally T-shaped and extends longitudinally of the ramp. The upright part of the T is pivoted to the hinge axis 9 between the ramp sections and has one end of the cross part of the T connected to the ramp 6 by a hydraulic piston and cylinder unit 15, and its other end connected to the ramp section 8 by a tackle unit 17 and arranged to rest upon this section 8 when the ramp is in its unfolded position. <IMAGE>

Description

SPECIFICATION A cargo loading and unloading assembly for ships The present invention relates to a cargo loading and unloading assembly for ships, of the type having a runway ramp comprising at least two sections which are hingedly connected to each other and to the ship about horizontal axes and which may extend in the fore-and-aft direction of the ship or under a, possibly adjustable angle to that direction, and wherein the connection between one ramp section and the section following the same in the direction of length of the ramp there comprises at least one element which is positioned to the side of the ramp and adapted to assist in the adjustment of the angle between the planes of the two ramp sections.

In such ramps, it has been difficult to bring the ramp to move from the stowed away position wherein the ramp sections are folded one against the other and -against the stern end of the ship, and at the same time secure the position of the sections relatively to each other and relatively to the ship at various positions of the ship relatively to shore dependent upon the tide water or the deplacement of the ship.

According to the invention, such difficulties are to a high degree avoided thereby that each connecting element is shaped generally as a T and extends longitudinally of the ramp with the vertical of the T pivotably mounted at or near to the hinge axis between the two sections and with one end of the horizontal of the T connected to that of the two sections which is the foremost in the fore-and-aft direction of the ship through a hydraulic piston and cylinder unit, while the other end of the horizontal of the T is connected to the other ramp section through a tackle unit and may rest upon this section when the ramp is in unfolded position.

In the assembly according to the invention, the hydraulic piston and cylinder unit, at the beginning of the unfolding of the ramp from stowed away position to operational position, would subject the foremost section and thereby also the aft section which is folded in against the foremost one, to a push through the connecting element in the aft direction relatively to a fixed point, so that the two sections are moved out of the slighlyforwardly inclined position adapted when folded against each other.Further, the hydraulic unit, in the more or less unfolded position of the ramp may serve as an adjustable, solid connection between the connecting element and the foremost section, so that the aft section may swing freely to a desired position under the control of the tackle unit at the same time as the tackle unit, in the fully unfolded position of the ramp would keep the aft section fixed relatively to the connecting element and thereby relatively to the foremost section due to the fact that the tackle connection is capable of transmitting stretch, but not pressure forces.

Further features of the assembly according to the invention and the advantages of the same will appear from the following description of an embodimentwhich is shown in the accompanying drawings.

Figure 1 is a side view, showing to the right a ramp assembly according to the invention in a completely folded position, and to the left the assembly during unfolding or folding movement.

Figure 2 is a side view of the assembly in a completely unfolded position.

Figure 3 is a view, as seen from above of the assembly in unfolded position.

In the drawings, 1 is the stern end of a ship which is provided with a gate 2, the plane of which may extend athwartship or, as shown in Figure 3, obliquely to the fore-and-aft direction of the ship. The gate 2 may be weatherproofly closed by means of a flap 3 which may be swung up as shown in Figure 2.

The gate 2 is provided with a gallows 4 adapted to control a runway ramp having fore-and-aft extending side boards 5 so that the ramp may be positioned well protected against the weather when in folded position. In the embodiment shown, the ramp assembly comprises a foremost section 6 which is pivotably mounted about a horizontal axis 7 at the lower edge of the gate 2, and an aft section 8 which is pivotably connected to the section 6 about a horizontal axis 9 and is provided with a landing flap 10 which is pivotably connected to the section 8 about a horizontal axis 11 for the purpose of adapting the ramp to a surface of, for instance a quay 12.

To at least one side of the ramp, the drawings show to both sides, and between the sections 6 and 8 there is arranged a connecting element 13 which extends longitudinally of the ramp, and which, in side view, is substantially of T shape. The free end of the vertical or upright part of the T is pivotably mounted in or near to, the drawings show in, the axis 9 between the sections 6 and 8, while the foremost end 14 of the horizontal or cross part of the T is connected to the foremost section 6 through a double acting hydraulic cylinder and piston unit 15 and the aft end 16 of the horizontal part of the T is connected to the aft section 8 through a tackle unit 17 which is controlled from a winch 18 accomodated on the connecting element 13. The aft end 16 of the connecting element 13 is arranged to co-operate with the top surface of the aft section 8through an abutment 19.In a point 10 at the top surface of the connecting element 13, art a greater distance from the end 14 than from the end 16, the element 13 is connected to the gallows 4 through a tackle unit 21 which is controlled from a winch 22 on the ship.

The assembly according to the invention is operated in the following manner, it being assumed that the ramp initially is in the position which is shown to the right in Figure land is to be brought through the position which is shown to the left in Figure 1 into the position, which is shown in Figures 2 and 3 and then maintained in this last position, care being taken to possibly varying height differences between the ship and the quay.

In the initial position, the sections 6 and 8 of the ramp are folded together against the aft end of the ship, with the center of gravity of the ramp in or near to, preferably slightiy forward of a vertical line through the hinge 7. The gate 2 is weathertightly closed by means of the flap 3 and 4 essential parts of the control appliances are positioned well protected between the gallows side boards 5. In this position of the ramp,theTshaped element 13 is positioned against the ramp section 6,the hydraulic unit 15 being fully retracted. The end 14 of the element 13 is resting against an abutment 23 in the gallows 4.

The unfolding of the ramp is initiated by energisation of the hydraulic unit 15, so that the end 14 of the element 13 kicks against the abutment 23 and the entire ramp assembly is swung outwardly to the effect that the same will tend by gravity to continue its downward movement. This movement is controlled by means ofthetackle unit21,the element 13 being maintained in the position shown to the left in Figure 1 by means of the hydraulic unit 15, and the angle between the ramp sections 6 and 8 gradually opening through the cooperation between the units, 15, 17 and 21.Due to the fact that the element 13 is of T shape and may pivot about the hinge 19, the control of the movements of the sections 6 and 8 is simple and little force consuming, until the abutment 19 on the section 8 is abutting against the end 16 of the element 13 that the members 13 and 8 constitute a rigid unit.

When the sections of the ramp are in the positions shown in Figure 2, with the landing flap 10 resting against a quay or the like 12, the clearance between the quay 12 and the ramp sections 6 and 8 may be adjusted by means of the unit 21 and the unit 15, so that variations in the height of the hinge 7 may be absorbed while maintaining a suitable angle between sections 6 and 8.

When arranging one hydraulic unit 15to each longitudinal side of the section 6, a possible oblique position of the hinge 7 may be compensated.

During such movements of the ramp sections which are required in case of variations in height of the ship relatively to the quay, it is of importance that the length of the tackle unit 21 is subjected to as small variations as possible. Consequently, the point 20 is positioned at a distance above the top surface of the T shaped element 13, and preferably in a line at right angles to a line through the axis of the hinge 9 and the top pulley 20b in the unit 21 when the sections are in the position shown in Figure 2.

However, for the purpose of reducing the additional momentum caused by the unit 21 to the element 13, and thereby reduce the energy consumption of the hydraulic unit 15, the point 20 is, as shown, positioned at a small distance aft to the middle of the top surface of the element 13.

Claims

1. A cargo loading and unloading assembly for a ship of the type having a ramp comprising at least two sections which are hingedly connected together and to the ship about substantially horizontal axes, wherein the connection between one ramp section and an adjacent section comprises at least one element positioned on one side of the ramp and adapted to assist in the adjustment of the angle between the planes of the two ramp sections, the or each connecting element being generally T-shaped, extending longitudinally of the ramp, and having the upright part of the T pivotally mounted at or near to the hinge axis between the two ramp sections, one end of the cross part of the T connected to the foremost of the two ramp sections by a hydraulic piston and cylinder unit, and the other end of the cross part of the T connected to the other ramp section by a tackle unit and being capable of resting upon this section when the ramp is in its unfolded position.

2. An assembly as claimed in claim 1, wherein the hydraulic cylinder and piston is of the double acting type.

3. An assembly as claimed in claim 1 or 2, wherein the tackle unit is under control of a winch arranged on the connecting element.

4. An assembnly as claimed in claim 1,2 or 3, wherein the height of the hinge connection between two ramp sections is under the control of a second tackle unit connected to a position which is fixed relatively to the ship, said second tackle unit being connected to the connecting element at a position aft of the middle of the cross part of the T-shaped element.

5. A cargo loading and unloading assemblyfora ship, constructed, arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.