GB2031983A

GB2031983A - Moulded ladder rung

Info

Publication number: GB2031983A
Application number: GB7923821A
Authority: GB
Original assignee: Robb W M
Current assignee: Robb W M
Priority date: 1978-07-08
Filing date: 1979-07-09
Publication date: 1980-04-30
Also published as: GB2031983B

Abstract

A neoprene or rubber ship's ladder rung 1 includes internal reinforcement bars 12. The ends of the bars are hooped and surround through-bores 3 for the ladder's ropes 13. The rung is formed in a mould box 7 having shouldered studs 8 which both support the reinforcement and form the bores 3. <IMAGE>

Description

SPECIFICATION Rubber moulded step The present invention relates to ladders of the type used for boarding ships and particularly for a step of rung for use in such a ladder.

One previous ship's boarding ladder comprises a series of transverse wooden boards constituting steps or rungs which were carried by longitudinally extending ropes arranged vertically in use. Such a ladder had the advantage of being quickly and easily positioned for use e.g. for boarding a pilot, but had the disadvantage of being inflammable, and giving rise to damage when jammed between the ship and another structure, e.g. jetty; additionally the ladder was prone to rotting. In an improved ladderthe wooden rungs were replaced by plastics rungs or steps, e.g. of polypropylene, but these were relatively rigid and damage was still likely when jamming of the ladder occurred.

It is an object of the present invention to obviate or mitigate these disadvantages.

According to the present invention there is provided in or for a ladder a step or rung comprising a moulded flexible member made of natural or synthetic rubber or plastics material, reinforcing elements in the member, and having means to enable attachment of the member to vertical support bars or cables.

Preferably the attachment means comprises apertures in the member and the reinforcing elements can be constituted by bars or wires extending longitudinally in the member.

Preferably the bars have hooped ends each encircling a respective aperture. The member preferably comprises a flat strip and is preferably made of neoprene.

The above step according to the present invention can have considerable flexibility so that there is less likelihood of damage when jamming occurs, but longitudinal deflection can be minimised by virtue of the reinforcing elements; and the step can be rot proof and fire proof. Additionally the step can be provided with non-slip characteristics.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 shows a pictorial view of a step according to the present invention; Fig. 2 shows a cross sectional view of the step of Fig. 1; Fig. 3 shows the top mould plate of a mould for making the step of Fig. 1; and Fig. 4 shows the bottom mould for the step.

Referring to the drawings a step 1 or rung for use in a ship's boarding ladder comprises a flat strip 2 of rubber or neoprene having through apertures 3 arranged in rectangular pattern through which apertures 3 pass the vertical support cables or rods 13 of the ladder. The ladder cable can comprise rope or alternatively may comprise metal bars having a coat ing of fire retardantfibreglass material. The step is made by a moulding process, and a suitable apparatus is shown in Figs. 3 and 4.The apparatus comprises a bottom mould 4 (Fig. 4) including a flat plate 5 having a rectangular frame plate 6 secured thereon to form the mould box 7 and of a depth equal to that of the step and four shouldered pins 8 are located in the mould for formation of the apertures, and a top bar mould 9 (Fig. 3) comprising a flat plate 10 with countersunk holes 11 arranged in a rectangular configuration. For moulding the top mould 9 is fitted over the bottom mould 4 with the pins and apertures registering.

The moulded neoprene step 1 has considerable flexibility but to minimise longitudinal deflection longitudinal support bars or wires 12 are embedded in the strip and extend between pairs of apertures 3 in the strip and these bars 12 have hooped ends located at the aperture 3. These bars 12 can be shaped on the top mould 9 as shown and can be located on the pin shoulders 8 in the mould box prior to moulding.

By way of example, the step could be 18 ins. long by 5 ins. wide with a depth of 1 ins. The apertures could be arranged atthe corners of a rectangle 14 in. x4 ins. The reinforcing bars could be 10 mm in diameter, and made of spring steel.

With a ladder embodying the above step, a considerable degree of jamming can occur between the ship and the jetty say without excessive damage occurring due to the flexibility of the step. Also the step can be rot proof and fire resistant. The step can be provided with non-slip properties. In a modification, it would be possible to have a composite step including the above described neoprene step.

The step could be used in applications other than marine use. For example, the step could be used ashore in factories, hotels and other buildings. It will be understood thatthe step could be of a wide var- etyofsizes.

1. A step or rung for a ladder comprising a moulded flexible member made of natural or synthetic rubber or plastics material, reinforcing elements in the member, and having means to enable attachment of the member to vertical support bars or cables.

2. A step or rung as claimed in claim 1, wherein the attachment means comprises apertures in the member.

3. A step or rung as claimed in claim 1 or 2, wherein the reinforcing elements are constituted by bars or wires extending longitudinally in the member.

4. A step or rung as claimed in claim 3, wherein the bars have hooped ends each encircling a respective aperture.

5. A step or rung as claimed in any one of the preceding claims, wherein the member comprises a flat strip.

6. A step or rung as claimed in claim 5, wherein the strip is made of neoprene.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Rubber moulded step The present invention relates to ladders of the type used for boarding ships and particularly for a step of rung for use in such a ladder. One previous ship's boarding ladder comprises a series of transverse wooden boards constituting steps or rungs which were carried by longitudinally extending ropes arranged vertically in use. Such a ladder had the advantage of being quickly and easily positioned for use e.g. for boarding a pilot, but had the disadvantage of being inflammable, and giving rise to damage when jammed between the ship and another structure, e.g. jetty; additionally the ladder was prone to rotting. In an improved ladderthe wooden rungs were replaced by plastics rungs or steps, e.g. of polypropylene, but these were relatively rigid and damage was still likely when jamming of the ladder occurred. It is an object of the present invention to obviate or mitigate these disadvantages. According to the present invention there is provided in or for a ladder a step or rung comprising a moulded flexible member made of natural or synthetic rubber or plastics material, reinforcing elements in the member, and having means to enable attachment of the member to vertical support bars or cables. Preferably the attachment means comprises apertures in the member and the reinforcing elements can be constituted by bars or wires extending longitudinally in the member. Preferably the bars have hooped ends each encircling a respective aperture. The member preferably comprises a flat strip and is preferably made of neoprene. The above step according to the present invention can have considerable flexibility so that there is less likelihood of damage when jamming occurs, but longitudinal deflection can be minimised by virtue of the reinforcing elements; and the step can be rot proof and fire proof. Additionally the step can be provided with non-slip characteristics. An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 shows a pictorial view of a step according to the present invention; Fig. 2 shows a cross sectional view of the step of Fig. 1; Fig. 3 shows the top mould plate of a mould for making the step of Fig. 1; and Fig. 4 shows the bottom mould for the step. Referring to the drawings a step 1 or rung for use in a ship's boarding ladder comprises a flat strip 2 of rubber or neoprene having through apertures 3 arranged in rectangular pattern through which apertures 3 pass the vertical support cables or rods 13 of the ladder. The ladder cable can comprise rope or alternatively may comprise metal bars having a coat ing of fire retardantfibreglass material. The step is made by a moulding process, and a suitable apparatus is shown in Figs. 3 and 4.The apparatus comprises a bottom mould 4 (Fig. 4) including a flat plate 5 having a rectangular frame plate 6 secured thereon to form the mould box 7 and of a depth equal to that of the step and four shouldered pins 8 are located in the mould for formation of the apertures, and a top bar mould 9 (Fig. 3) comprising a flat plate 10 with countersunk holes 11 arranged in a rectangular configuration. For moulding the top mould 9 is fitted over the bottom mould 4 with the pins and apertures registering. The moulded neoprene step 1 has considerable flexibility but to minimise longitudinal deflection longitudinal support bars or wires 12 are embedded in the strip and extend between pairs of apertures 3 in the strip and these bars 12 have hooped ends located at the aperture 3. These bars 12 can be shaped on the top mould 9 as shown and can be located on the pin shoulders 8 in the mould box prior to moulding. By way of example, the step could be 18 ins. long by 5 ins. wide with a depth of 1 ins. The apertures could be arranged atthe corners of a rectangle 14 in. x4 ins. The reinforcing bars could be 10 mm in diameter, and made of spring steel. With a ladder embodying the above step, a considerable degree of jamming can occur between the ship and the jetty say without excessive damage occurring due to the flexibility of the step. Also the step can be rot proof and fire resistant. The step can be provided with non-slip properties. In a modification, it would be possible to have a composite step including the above described neoprene step. The step could be used in applications other than marine use. For example, the step could be used ashore in factories, hotels and other buildings. It will be understood thatthe step could be of a wide var- etyofsizes. CLAIMS

6. A step or rung as claimed in claim 5, wherein the strip is made of neoprene.

7. A step or rung as claimed in any one of the preceding claims and made by a moulding process.

8. A step or rung substantially as hereinbefore described with reference to and as illustrated in Figs 1 and 2 of the accompanying drawings.