GB2326905A - Ladder e.g. for climbing masts - Google Patents

Description

DESCRIPTION This invention concerns ladders, especially ladders suitable for use in climbing masts of yachts and the like.

Ladders for climbing yacht masts are known which comprise a webbing strap with foot loops on opposite sides and out of phase. The strap has a ring at one end for coupling to a halyard and slugs at spaced intervals to fit a corresponding slot of the mast. The mast slot usually accommodates slugs fixed to a sail. A problem with such a ladder is that it is generally unstable and hence difficult to climb and stand on because it can swing from side to side. When the ladder is being used for working at the top of a mast, it is important to have stability otherwise the task in hand can be almost impossible to complete.

An object of this invention is to provide an improved ladder suitable for use in climbing masts of yachts and the like.

According to this invention there is provided a ladder suitable for use in climbing masts of yachts and the like comprising three straps or the like arranged generally parallel and spaced apart and a plurality of spaced, relatively rigid rungs, each secured to each of the straps.

The preferred rungs of ladders of the invention are made of metal, such as steel or aluminium, or of plastics. The rungs may be made in one or more parts.

In one preferred form of the invention, especially but not exclusively suitable for metal rungs, the two parts are of L-section and are fixed together back to back with the straps therebetween to form flat-topped rungs. The rung parts may be fixed together in any suitable way, although rivetting is preferred.

The rungs may also be formed in two parts from plastics mouldings also possibly generally of L-section. Whilst the straps may be fixed between the mouldings, it is preferred that the straps be threaded through one of the mouldings and be retained there rather than relying on rivetting or the like through the straps to hold the rungs in place. Such threading may be aided by a retaining clip that can engage in a loop of a strap and prevent same being pulled out of the plastics moulding.

One piece rungs may also be possible for use in the ladders of the invention.

It may be possible to mould rungs from plastics material preferably with through holes or slots for the straps. Alternatively, sheet metal may be cut and folded to form a rung again preferably with through holes or slots for the straps. The preferred profile of such one-piece rungs will be T-shaped in section.

The straps may be of any suitable material bearing in mind that the ladder should be sufficiently strong at least to carry the weight of an adult. Woven nylon webbing has been found to be particularly suitable for making the straps.

At its intended top end, the ladder has its three straps fixed to a ring or the like, which may be used to fasten the ladder to hoisting means, such as a rope as used to raise a sail.

For use with a mast, the ladder of the invention preferably has means for holding the ladder close to the mast. For retaining sails masts are provided with a longitudinal slot having a wider base than entry in which generally T-shaped slugs slide, the tails of the T's being fixed to the sail and the heads of the T's being retained in the slot. The means for holding the ladder close to the mast preferably comprises similar slugs preferably fixed to a central strap of the ladder at spaced intervals.

The intended bottom ends of the ladder straps preferably have loops whereby the bottom ends of the straps can be fixed to suitable securing points on a deck or at some other location.

It may be advantageous to have mounted behind each rung one or more blocks of anti-rub material to reduce likelihood of damage being caused to the mast by the ladder rungs as the ladder is being used or raised and lowered.

On one or more of the straps usually the central strap, an attachment device for attachment of commonly used slides may be provided. A preferred attachment device comprises a back plate and a generally U-shaped member with a cross bar between its ends, the two items being secured together back to back one on either side of the strap.

This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front perspective view of a ladder according to the invention; Figure 2 is a rear view of the ladder of Figure 1; Figure 3 is a section through the ladder of Figure 1 fitted to a mast of a yacht; Figure 4 shows a modification to the ladder of Figure 1; Figure 5 is a rear view of another ladder according to the invention; Figure 6 is a front view of the ladder of Figure 5; Figure 7 is a section through a rung of the ladder of Figure 5; Figures 8A and B are end and side views respectively of a retaining clip used in the rung of Figure 7; Figure 9 is a section through one moulding for the rung shown in Figure 7; and Figure 10 is a section through the other moulding for the rung shown in Figure 7.

Referring to the accompanying drawings a ladder 10, particularly suitable for use on yachts, comprises three webbing straps 12, 14 and 16 connected at an intended top end to a ring 18. The ring may be attached to a halyard by means of a shackle (not shown) whereby the ladder may be raised up a mast 20 in similar manner to a sail. The straps are preferably of woven nylon or other suitable material.

The three webbing straps 12, 14, 16 have rungs 22 fixed thereto so that from the top rung downwards the straps are held parallel. The rungs 22 comprise back to back L-section metal strips 24. The strips 24 are firstly pre-drilled where they will overlie the straps 12, 14, 16. A strip 24 is then positioned over the straps and a hot iron pushed through the pre-drilled holes to form holes through the webbing straps and also to heat seal the edges of the holes in the webbing straps to prevent them from fraying. The rung straps are then rivetted back to back sandwiching the webbing straps between them.

At the bottom end of each strap 12, 14, 16 a loop 26 is formed, which can be used to secure the bottom end of the ladder. The centre webbing strap 14 has secured to it at spaced intervals slugs 28. The slugs are generally T-shaped in plan view and the head of the T is shaped to fit a T-shaped slot 30 in the face of a mast 20. The slugs 28 are slid into the slot via a layer opening at or near the base of the mast whereafter they are retained in the slot as the ladder is raised up the mast. Thus, the slugs hold the ladder close to the mast and limit lateral and twisting movements of the ladder in use.

Figure 4 shows addition of a block 32 of anti-rub material on the back of the rungs 22 to reduce risk of damage to mast 20 by the rungs rubbing against it.

Turning to Figures 5 to 10 of the accompanying drawings, a ladder 100 comprises three webbing straps 102, 104 and 106 connected at an intended top end to a ring (not shown). The straps are preferably of woven nylon or other suitable material. The three straps 102, 104, 106 have rungs 108 fixed thereto. The rungs 108 comprises first and second plastics mouldings 110 and 112 (Figures 9 and 10), the first having on its mating face pegs 114 to mate with holes 116 of the second moulding, the two parts being secured together by means of screws or the like through the mating parts.

The two mouldings each have a lip 118, 120 respectively on one side so that together back to back the mouldings form T-section rungs.

To fasten the rungs to the straps, one of the mouldings 110 has three pairs of parallel slots 124, 126, one pair for each strap and forming a bar around which a strap can be secured. Each strap is passed through the top slot 124, folded back on itself to form a loop 127 and then passed back through the same slot and down behind the moulding. The loop 127 is pushed into the lower slot 126 and a generally rectangular retaining clip 128, having an opening at one corner, has its side 130 with a free end fed through the loop 127 with the opposite side of the clip behind that part of the strap coming back through the top slot. Then the other moulding part is fixed to the first moulding. The strap is, therefore, held between the two moulding parts and the clip prevents the rungs from sliding down the strap.

As with the ladder of the first embodiment, the central strap 104 has slugs on it to locate the ladder slidingly on the mast.

The central strap 104 also has a slide attachment device 134 fixed thereto.

Claims (25)

1. A ladder suitable for use in climbing masts of yachts and the like, the ladder comprising three straps or the like arranged generally parallel and spaced apart and a plurality of spaced, relatively rigid rungs, each secured to each of the straps.

2. A ladder as claimed in claim 1, wherein the rungs are made of at least two parts.

3. A ladder as claimed in claim 2, wherein the two parts of each rung are of Lsection and are fixed back to back with the straps therebetween to form flat-topped rungs.

4. A ladder as claimed in claim 2 or 3, wherein the rung parts are fixed together by rivetting.

5. A ladder as claimed in any one of claims 1 to 4, wherein the rungs of the ladder are made of metal, such as steel or aluminium.

6. A ladder as claimed in any one of claims 1 to 4, wherein the rungs are made from plastics mouldings.

7. A ladder as claimed in claim 6, wherein the straps are fixed between the mouldings.

8. A ladder as claimed in claim 6, wherein the straps are threaded through one of the mouldings and retained there.

9. A ladder as claimed in claim 8, wherein the threading is aided by a retaining clip that can engage in a loop of the strap and prevent the same being pulled out of the plastics moulding.

10. A ladder as claimed in 1, wherein one piece rungs are provided.

11. A ladder as claimed in claim 10, wherein the rungs are moulded from plastics material.

12. A ladder as claimed in claim 10, wherein the rungs are produced from sheet metal cut and folded to form the rung.

13. A ladder as claimed in claim 11 or 12, wherein the rungs have through holes or slots provided therein for the straps.

14. A ladder as claimed in any one of claims 10 to 13, wherein the profile of the one piece rung is T-shaped in section.

15. A ladder as claimed in any one of the preceding claims, wherein the straps are made of woven nylon webbing.

16. A ladder as claimed in any one of the preceding claims, wherein at the intended top end of the ladder, the three straps of the ladder are fixed to a ring or the like which may be used to fasten the ladder to hoisting means.

17. A ladder as claimed in any one of the preceding claims, wherein the ladder is provided with means for holding the ladder close to a mast along at least part of the its length.

18. A ladder as claimed in claim 17, wherein the holding means comprises a plurality of T-section slugs.

19. A ladder as claimed in claim 18, wherein the slugs of the ladder are fixed to a central strap at spaced intervals.

20. A ladder as claimed in any one of the preceding claims, wherein the intended bottom ends of the ladder straps are provided with loops whereby the bottom ends of the straps may be fixed to suitable securing points on a deck or at some other location.

21. A ladder as claimed in any one of the preceding claims, wherein one or more blocks of anti-rub material is mounted behind each rung.

22. A ladder as claimed in any one of the preceding claims, wherein one or more of the straps is provided with an attachment device for attachment of commonly used slides.

23. A ladder as claimed in claim 22, wherein the attachment device comprises a back plate and a generally U-shaped member with a cross-bar between its ends, the two items being secured together back to back one on either side of the strap.

24. A ladder as claimed in claim 22 or 23, wherein the attachment device is provided on the central strap.

25. A ladder for use in climbing masts of yachts and the like substantially as hereinbefore described and with reference to Figures 1 to 3, Figure 4 and Figures 5 to 10 of the accompanying drawings.