WO2009116920A1

WO2009116920A1 - Bathing and rescue ladder

Info

Publication number: WO2009116920A1
Application number: PCT/SE2009/000133
Authority: WO
Inventors: Bertil STRÖMBERG
Original assignee: Stroemberg Bertil
Priority date: 2008-03-17
Filing date: 2009-03-13
Publication date: 2009-09-24
Also published as: SE0800612L; SE531796C2

Abstract

Bathing and rescue ladder one end of which is mounted on or near the gunwale (56) or upper end of the transom of a boat and may be pivoted around an axis that is parallel to the gunwale or the upper end of the transom, so that the ladder can be swung at least between a position where it hangs more or less perpendicularly down into the water and a position where the free end of the ladder floats on or near the water surface, and the said free end of which is provided with one or more flotation devices, which in a passive state lacks or lack buoyancy but, when the ladder hangs more or less perpendicularly into the water, can be activated and thereby imparted sufficient buoyancy to lift a person that stands on or holds himself close to the ladder and keep the free end of the ladder floating at or near the water surface even when a person lies on the ladder.

Description

Bathing and rescue ladder

The present invention concerns a bathing and rescue ladder, one end of which is mounted on or near the gunwale or upper end of the transom of a boat and may be pivoted around an axis that is parallel to the gunwale or the upper end of the transom, so that the ladder can be swung at least between a position where it hangs more or less perpendicularly down into the water and a position where the free end of the ladder floats on or near the water surface, and the other, free, end of which is provided with one or more flotation devices, characterised in that the flotation device or flotation devices hi a passive state lacks or lack buoyancy but, when the ladder hangs more or less perpendicularly, can be activated and thereby imparted sufficient buoyancy to lift a person that stands on or holds himself close to the ladder and keep the free end of the ladder floating at or near the water surface even when a person lies on the ladder.

It is well known that it is hard for a person that has fallen overboard in rough weather to get on board again even if the boat is provided with a conventional bathing and rescue ladder, i.e. a ladder that is vertically mounted along the side or the transom of the boat, and that even if the ladder protrudes a bit under the surface. There are several reasons for this. First, it is difficult to hold unto a ladder fixed to the boat's side or transom when the boat is heaving or healing in the sea, secondly, the clothes become heavy and clumsy from the water that they have absorbed and thirdly, the person's strength and agility is quickly reduced if the water is cold. Some authors therefore suggest that the person be lifted on board with the help of the mainsheet or with the help of some other hoisting device such as a halyard or a backstay. Others have suggested that a headsail or staysail is lowered into the water to form a sort of cradle and that the person in distress is thereafter dragged into the cradle, whereafter one end of the headsail or staysail is hoisted so that the cradle formed by the sail with the person inside can be swung inboard.

US 4613013 describes a combined ladder and cradle, which can either be used a ladder hanging along the boat's side or as a rescue cradle, hi which case the end of the ladder that is not fixed to the boat's gunwale is attached to a hoisting device and hoisted, so that the ladder forms a cradle where the person in distress is placed, whereafter the free end is hoisted further, thereby lifting the person in distress. The described methods presuppose that the crew remaining on board quickly can arrange the necessary hoisting arrangements, something which can be difficult on a sailing boat and impossible on a motorboat without a mast. Using the mainsheet for hoisting the person in distress on board necessitates, if the boat does not have a sufficiently strong topping lift or other arrangement to lift the boom, that the mainsail is taken down, that the mainsail halyard is attached to the boom, which often requires that the halyard is extended by an extra line. It also requires that the inboard end of the mainsheet or mainsheet tackle is released from the mainsheet traveller or other fixing point in the boat and attached to the person in distress. Using a headsail or staysail entails often risky work on the fore-deck even if a spare sail is used. It may also be difficult to bring the person in distress into the cradle formed by the sail without his head being wholly or partially immersed in the water. The same problem applies to use of the device described in US 4613013.

US 3411166 describes an inflatable boarding ladder and paddle combination, intended to be used either as a ladder or as a raft. As can be seen from figure 8, however, the device is intended to hang vertically along the boat's side when used as a ladder. The device is moreover fixed to the boats gunwale at only one point, which makes it unsuitable for use as a ramp to haul a person in distress on board. When used as a raft, the device is not connected to the boat and can not be used to take a person in distress on board.

US 7017709 Bl describes a safety ladder, which is supported by and can be pivoted around an axle that can be arranged either at right angles to or parallel to a seawall or boat side. The extreme end of the ladder is provided with a float, which is intended to support the extreme end of the ladder above the water, when the ladder is not deployed. The float, however, is intended to sink when it is subjected to a force as small as 2 - 3 pounds (0, 9 - 1, 4 kg) and cannot carry the weight of a person. The support for the ladder is moreover provided with a stop that prevents the ladder from pivoting further downwardly than until its angle to the water surface is 45 . If the ladder is fixed to the transom or railing of a boat, the ladder will therefore follow the boats motions in the sea so as to make it difficult for a person on the ladder to get onboard. If the ladder is fixed to the transom, the ladder will sink when the stern sinks and the stem rises and be lifted under opposite conditions. Correspondingly, a ladder fixed to athwart on the railing will sink to a more perpendicular position if the boat heals toward the side on which the ladder is fixed and be lifted when the boat heals the other way. A person trying to board the boat with the help of the ladder will thus at times lack support from the ladder, which sinks under him or her. If the stop is arranged so that the ladder's angle to the water surface is small when the boat is upright, for example 30 or less, the extreme end of the ladder can even be lifted out of the water, when the boat rolls in the waves, which of course makes it difficult for a person in distress to catch and use the ladder. Finally, the ladder is intended to be used exclusively as a ladder and therefore is provided with fixed steps, which prevents that the ladder is used as a ramp to haul a person onboard.

US 5829380 A describes a boarding platform for dogs, one end of which is fixed to a drop ladder of a boat by a clamping device or other mounting bracket and the other end of which is provided with two inflatable flotation bags. The flotation bags, however, are intended to sink when the dog steps on the platform and seem to be intended to be inflated before the device is launched into the water. The device is further provided with ridges intended aid in footing for the dog while deterring adults from using the device.

The purpose of the present invention is to create a device that is permanently fixed to the boat, that can be used without major preparations and which can be used as a ramp to haul the person in distress on board without requiring that he climbs or is hoisted over the side or railing of the boat. The purpose is achieved by arranging a vertically pivotable ladder along a boat's gunwale or transom, which ladder is provided with one or more flotation devices at its free end, which flotation device or devices keep the free end of the ladder floating after it or they has or have been activated, thereby giving the ladder an angle to the water surface which is less than 90°. To facilitate for a person in distress to get onto the ramp, the flotation device or devices are arranged so that it or they can be activated when the ladder is hanging more or less perpendicularly and the person in distress stands on or hangs along the ladder.

The invention thus concerns a bathing and rescue ladder, one end of which is mounted on or near the railing or gunwale or upper end of the transom of a boat and may be pivoted around an axis that is parallel to the gunwale or the upper end of the transom, so that the ladder can be swung at least between a position where it hangs more or less perpendicularly down into the water and a position and a position where the free end of the ladder floats on or near the water surface, characterised by the fact that the said free, end of the ladder is provided with one or more flotation devices, which in a passive state lacks sufficient buoyancy to keep the free end floating, but which, when the ladder hangs more or less perpendicularly down into the water, can be activated and thereby imparted sufficient buoyancy to lift a person that stands on or holds himself close to the ladder and to keep the free end of the ladder floating at or near the water surface even when a person lies on the ladder.

In the following the words "flotation device" is used to denote one or more flotation devices.

When the ladder is used as a rescue device, the ladder is brought to hang vertically in the water. The person in distress can thereafter stand on one of the steps of the ladder or haul himself or be hauled close to and aligned with the ladder, and the flotation device can thereafter be activated, which causes the ladder to swing out from the boat's side or the transom, the person in distress wholly or partly resting on the ladder, and the free end of the ladder floating at or near the water surface. The ladder can now be used as a ramp to haul the person in distress on board, either by his hauling himself onboard by gripping consecutive rungs or steps of the ladder and pulling himself up, or by his being hauled on board by crew remaining on board. The force required is considerably lower than the force required to hoist the person in distress vertically out of the water. Should manual force nevertheless not be sufficient to haul the person in distress on board, a line can be attached to the lifting sling on his life west or harness, if he wears any of these, and led over the upper end of the ladder directly to a sheet or halyard winch, e.g. on the opposite side of the boat, without the need to arrange blocks or tackle to achieve a vertical lifting force.

The flotation device can consist of an inflatable bladder. This can be fixed on the ladder, but is preferably detachably attached thereto, so that it can be removed when the ladder is used as a bathing ladder during sheltered conditions. The flotation device can also consist of a combination of two or more inflatable bladders. Also other kinds of flotation devices are possible. The device can, e.g., consist of a rigid, fluid impermeable container, which may be integrated into the ladder, and which is filled, or can be filled, with a liquid which is as heavy as or heavier than water and which can be pumped out of the container.

The flotation device, when activated, should have sufficient buoyancy to lift a person that stand on or holds himself close to the ladder and to keep the free end of the ladder floating also when the ladder is weighed down by a person resting thereon. It may, however, be desirable to make it possible to get onto the ladder even after the flotation device has been activated, either because a first rescue attempt has failed and the person in distress ended up in the water again, or because further persons need to be taken on board. If the buoyancy of the flotation device is high it may therefore be desirable to design the flotation device so that the free end of the ladder does not lie considerably higher than the water surface even when not weighed down by the load of a person.

The buoyancy required to keep the free end of the ladder floating at or near the surface when weighed down by a person depends on the shape of the flotation device, on the weight of the person in distress and the ladder and on where on the ladder the person in distress is placed. If the ladder is intended for rescuing full-grown persons, the net buoyancy of the flotation device, i.e. the theoretical buoyancy of the device less the weight of the device and the force exerted on the device by the unloaded weight of the ladder, should not be less than 100 N and should preferably be 250 N or more.

The ladder should be sufficiently long to carry at least the main part of a person's torso and to give it a sufficiently small angle against the water surface to facilitate taking the person in distress on board. The angle should preferably not be more than 45° and most preferably not more than 30°. The length of the ladder should therefore preferably be at least double the height of the topside or transom of the boat when the boat is floating upright. It is also advantageous if the ladder is sufficiently long for the distressed person to be able to place a foot on one of the rungs or steps of the ladder without difficulty, when the ladder is hanging perpendicularly into the water.

If the ladder can not be made sufficiently long, the flotation device can be designed to expand in the longitudinal direction of the ladder when inflated, to give the combination ladder/flotation device the desired length. If the ladder is arranged on the side of the boat, the ladder's angle to the sea will continuously change as the boat rolls in the sea. If the ladder is arranged on the transom the angle will change as the boat heaves in the sea due to waves coming from abaft or ahead of the boat. This fact can be used for taking the person in distress on board in such a way that he is hauled or hauls himself on board when the ladder's angle to the sea is small and is only held or holds himself to the ladder when the angle is greater.

For the ladder to be used as a ramp to haul the person in distress on board, it should be sufficiently broad to prevent the person in distress falling off the ladder over the side. The ladder should suitably be at least 30 cm and preferably about 40 cm. The ladder should also be sufficiently rigid to carry the person in distress even under load. This does not mean that the ladder needs to be rigid in the absolute sense of the word. A downward bend of 10% of the length of the ladder does not materially impair the function of the ladder. If the ladder is collapsible, it should be designed so as not to accidentally collapse when used as a rescue ramp.

To facilitate taking the person in distress on board, the rungs or steps of the ladder should be designed to facilitate hauling the person over them. They can, e.g., be made from round tubes. If they are designed as steps, flat on the topside, they can be made to pivot around their longitudinal axis, so that one of the flat sides of the step is parallel to the longitudinal plane of the ladder, when the ladder is used as a rescue ramp.

In the following the invention is described with reference to the drawings.

Figure 1 shows a perspective view of a collapsible bathing and rescue ladder according to the present invention. Figure 2 shows a detailed side view of the hinge 16 and lock 24 after the ladder has been folded out to an operative position. Figure 3 shows a view from above of the hinge 16 and lock 24. Figure 4 shows a detailed front view of the flotation device 37 and one of the steps 15. Figure 5 shows a section along the line A - B after the flotation device and lower steps have been removed to make the figure clearer. Figure 6 shows a side view of the ladder shown in figure 1 attached to the transom of a boat after the flotation device 37 has been activated and is floating on the water. Figure 7 shows a side view of another type of bathing and rescue ladder according to the invention attached to the side of a boat and figure 8 shows a front perspective view of the same bathing and rescue ladder.

The bathing and rescue ladder shown in figures 1 - 6 consists of an upper ladder part 1 and a lower ladder part 2.

The ladder part 1 consists of a tube 3, which has been bent to a U-shape, to form a connection part 4 and two stiles 5 and 6. Steps 15 extend between the stiles 5 and 6 are rotatably attached to the stiles 5 and 6. The connection part 4 is carried in two brackets 6 and 8, which are mounted on the transom 56 of a boat, and can pivot therein. The ladder part also carries two supports 9 and 10.

The ladder part 2 consists of a tube 11, which has been bent to a U-shape, to form a rung 12 and two stiles 13 and 14. Steps 15 extend between the stiles 13 and 14 and are rotatably attached to the stiles 13 and 14.

Ladder parts 1 and 2 are joined by the hinges 17 of a common type consisting of hinge parts 18 and 19 connected by a hinge pin in the form of a rivet 20 and hinge parts 21 and 22 connected by the hinge pin or rivet 23, respectively.

Ladder parts 1 and 2 are also provided with locks 24 and 25 to prevent unintentional collapse of the ladder during a rescue operation. The lock 24 consists of a lock chest 26 mounted on the stile 5 and a lock plate 27 with a hole 28, mounted on the stile 13. A locking bar 29 is arranged in the lock chest 26 along an axis parallel with the connection part 4 and in such a way that it passes through holes in the two side-walls of the lock chest 26. In the (inner) end of the locking bar 29 facing the stile 6 there is arranged a handle 30. A compression spring 31 presses against an annular stop on the locking bar 29. When the ladder is unfolded, the locking bar can be retracted with the help of the handle 30 so that its outer end is in the same plane as the outer wall of the lock chest 26. If the ladder is unfolded to such an extent that the lock plate 27 passes the locking bar 29, the lock plate 27 will keep the locking bar 29 in a retracted position until the locking bar 29 can slide into the hole 28, when the compression spring 31 will press the locking bar into the hole 28. The lock 25 has a corresponding design and consists of a lock chest 33, a locking bar 36 with a handle (not shown) and a stop (not shown) against which a compression spring (not shown) presses, and of a locking plate 34 with a hole 35.

As an alternative to separate hinges and locks the ladder can be provided with lockable hinges, for example of the type described in US 43733163

A flotation device 37 is fixed on the outside of stiles 13 and 14 between the rung 14 and the first of the steps 15.

The flotation device 37 consists of an inflatable bladder 38 fixed to a mounting plate 39, which in turn is fixed to the stiles 13 and 14 by rigging bolts 40 secured with locking rings 41. The bladder 38 is folded up and secured by hook bands 42 interacting with loop bands 43. An gas cartridge inflator 44 of the type commonly used in inflatable life vests and life rafts is attached to the bladder 38 by a flange 45, which is welded to the bladder 38, and a valve 46, which is attached to the flange 45 and extends through the mounting plate 39. The inflator 44 is armed with a gas cartridge 47, also of a type intended for life vests and life rafts. The inflator 44 can be activated by pulling a lanyard 48, which is connected to the inflator' s 44 activating arm 49. To prevent the bladder 38 from being damaged if the inflator 44 or the gas cartridge 47 unintentionally is subjected to large movements, the gas cartridge 49 is secured by a clamp 50. A valve 51 for connection to an air pump is welded to the bladder 38 with a flange (not shown). The valve can also be used to empty the bladder after use.

The bladder 38 can be made from a suitable flexible material which is gas impermeable and does not crack in the folds or in joints during storage. Suitable materials may, for example, be foils of chloroprene armed with fabric or fabric covered with that material or any other material used in air chambers in inflatable products such as life vests or life rafts. Surfaces which are exposed when the bladder is folded up are preferably provided with a cover of UV-resistant fabric to prevent deterioration due to ultra-violet rays. Alternatively the bladder 38 can consist of an outer cover of weather resistant, woven material with an inner bladder made from a flexible material such as butyl rubber or chloroprene. Each of the steps 15 consists of a plate or tread 52, carried by an axle 53, which passes through, and can rotate in, holes in the stiles 5 and 6 or 13 and 14, respectively. A protection plate 54 is attached to the underside of the tread 52 and is fixed to the axle 53. A stop 55 is fixed to the tread 52 but extends outside the same, so that it abuts the stile 5, or 13, when the tread is at right angles to the stile, and thereby prevents the step from pivoting beyond this position. If the step is rotated upwards, the stop will abut the stile 5, or 13, when the tread is almost parallel to the stile and thereby prevent the step from pivoting beyond this position.

Figure 6 shows the ladder shown in figure 1 floating on the water surface W. For the sake of clarity the water surface is only indicated and submerged parts are shown.

Figures 7 and 8 show another bathing and rescue ladder according to the invention with an activated flotation device floating on the water surface W. In the figures the water surface is only indicated for better clarity and submerged parts are shown.

The bathing and rescue ladder shown in figures 7 and 9 consists of a first ladder part 57 and three ladder elements 58, 59, and 60 telescopically inserted into each other and the ladder part 57, respectively. Ladder part 57 consists of two tubes or stiles 61 and 62 and two tubes or rungs 63 and 64 connected crosswise to the stiles 61 and 62 by the T-shaped joints 65, 66, 67, and 68. Each of the ladder elements 58, 59 and 60 consists of two tubes, 69 and 70, 71 and 72 and 73 and 74, respectively, and a tube or rung 75, 76, and.77, respectively, connected to tubes 69 and 70, 71 and 72, and 73 and 74, respectively, by joints 78 and 79, 80 and 81, and 82 and 83, respectively. The ladder element 58 can be moved in relation to the ladder element 59 from an inner position, where the joints 78 and 79 abut the joints 80 and 81, to an outer position where the tubes 69 and 70 are only partly inserted into the tubes 71 and 72, respectively, but are prevented from being moved further outward by a collar or thickening at or near the inner end of the tubes 69 and 70 interacting with internal stops in the tubes 71 and 72 in a way shown for example in JP 2003081178. The ladder element 59 may in a corresponding manner be moved within ladder element 60 and the ladder element 60 may in a corresponding manner be moved within the ladder part 57. The ladder elements are in a known manner locked in the extended position by a spring loaded locking bar (not shown) arranged in each of the joints 78 - 83 and passing into holes (not shown) in each of the tubes 69 - 74.

The ladder part 57 is pivotably attached to the U-shaped bracket 84 with bolts 85 and 86. The bracket 84 is fixed to the boat's gunwale 87 outside two gate type stanchions 88 and 89 for the guardrail, allowing the ladder to be swung up in the area between the stanchions 88 and 89 and secured to their upper parts.

A flotation device 90 is arranged at the ends of ladder elements 58 and 59. The flotation device consists of a first, U-shaped, inflatable bladder 91 which, when inflated, extends outside the free end of the ladder element 58, and a second inflatable bladder 92 arranged within the area limited by the inside of the bottom of the U and those parts of the legs of the U that extend outside the ladder element 58 and is attached to the bladder 91 along those parts. The bladder 91 is made from a flexible material with low elasticity and extensibility but with sufficient strength to withstand a gas pressure which is sufficient to make the inflated bladder 91 so rigid ihat it can support the weight of a person on the ladder without folding. The material and joints in the bladder 91 should preferably withstand a pressure of at least 10 kPa and more preferably a pressure of 20 kPa. The bladder 92 can be made from a more elastic material and does not need to be rigid when inflated.

Each of the bladders 91 and 92 are provided with an inflator 93 and 94, respectively, each carrying a gas cartridge 95 and 96, respectively. The inflators 93 and 94 can be activated by pulling the lanyards 97 and 98, respectively. To prevent the bladder 91 from bursting from too high a pressure, it is provided with a relief valve 99.

Attachments straps 100 and 101 made from several layers of the same material as that from which the bladder 91 is made, are welded or glued to the bladder 91. The attachment straps are also releasably attached to the joints 78 and 79 by nuts, which arranged in pockets in the straps 100 and 101 and screwed unto bolts welded to the joints 78 and 79 and passing through holes in the straps 100 and 101. Further attachment straps 102 and 103 are welded or glued to the bladder 91 near the joints 80 and 81 and in the same way attached to these joints by bolts welded to the joints and nuts arranged in pockets in the straps 102 and 103. Figure 8 shows the bathing and rescue ladder shown in figure 7. To support the ladder against forces working perpendicularly on the ladder it is provided with a guy 104, which extends from an attachment ring on the joint 79 to an attachment ring arranged on the railing of the boat. To prevent the person in distress from being swept off the ladder, the ladder is also provided with a net 107 extending between a first elastic line 108 extending from an attachment ring 109 on the bladder 91 to an attachment ring 110 on the stanchion 89 for the guardrail and a second elastic line 111 which extends between the attachment ring 109 to a second attachment ring on the stanchion 89.

Claims

1. Bathing and rescue ladder, one end of which is mounted on or near the gunwale (87) or upper end of the transom of a boat and may be pivoted around an axis that is parallel to the gunwale or the upper end of the transom, so that the ladder can be swung at least between a position where it hangs more or less perpendicularly down into the water and a position where the free end of the ladder floats on or near the water surface, and the other, free, end of which is provided with one or more flotation devices (37, 90), characterised in that the flotation device or flotation devices (37, 90) in a passive state lacks or lack sufficient buoyancy to keep the free end of the ladder floating but, when the ladder hangs more or less perpendicularly, can be activated and thereby imparted sufficient buoyancy to lift a person that stands on or holds himself close to the ladder and keep the free end of the ladder floating at or near the water surface even when a person lies on the ladder.

2. Bathing and rescue ladder according to the preceding claim characterised in that the flotation device (37, 90) consists of one or more inflatable bladders (38, 91, 92), which are provided with an inflator for use with a gas cartridge (44, 95, 96).

3. Bathing and rescue ladder according to any of the preceding claims characterised in that the flotation device has a buoyancy of 250 N or more.

4. Bathing and rescue ladder according to any of the preceding claims characterised in that the ladder is rigid or practically rigid in its lengthwise direction.

5. Bathing and rescue ladder according to any of the preceding claims characterised in that the flotation device (90) extends beyond the outer free end of the ladder and is sufficiently strong not to fold when the ladder is subjected to the weight of a person.

6. Bathing and rescue ladder according to claim 5 characterised in that the flotation device (90) consists of a first inflatable bladder (91), which when inflated extends beyond the outer free end of the ladder and is sufficiently strong not to fold when the ladder is subjected to the weight of a person, and a second inflatable bladder (92) attached to the first ladder (91).

7. Bathing and rescue ladder according to any of the preceding claims characterised in that the ladder consists of several ladder elements (57, 58, 59, 60) telescopically inserted into each other.

8. Foldable bathing and rescue ladder according to any of the claims 1-6 consisting of two ladder parts (1, 2) connected by hinges (16, 17) arranged on the side of the ladder facing outwards from the boat characterised in that the ladder parts on their opposite side are provided with locking devices (24, 25) to prevent unintentional folding of the ladder.

9. Bathing and rescue ladder according to any of the preceding claims characterised in that the ladder is provided with rungs with a circular section area.

10. Bathing and rescue ladder according to any of the preceding claims characterised in that the ladder is provided with steps having treads which can be rotated from a position at perpendicular to the lengthwise direction of the stiles to a position which is parallel or almost parallel to the lengthwise direction of the stiles.