[0001] The present invention relates to accomodation ladders for ships and of the kind comprising
a telescopic ladder having a first portion pivotally connected to a first platform
or the like connected to the deck of the ship and a second portion telescopically
displaceable relative to said first portion and pivotally carrying at its free end
a second platform which by means of a wire arrangement is supported by at least one
davit or the like, said wire arrangement being adapted to maintain said second platform
in a position substantially parallel to the deck of the ship independently of the
angle of inclination of the ladder portions, at least one supporting wire being arranged
for supporting the ladder and controlling the displacement of the moveable ladder
portion relative to said first ladder portion.
Background of the invention
[0002] A previously known embarkation device described in which British patent specification
GB-A-1 429395 comprises a ladder which is pivotally connected to the upper platform
at the deck of the ship and a lower platform which is pivotally attached to the lower
end of the ladder and which is maintained in a horizontal position by a wire arrangement
independently of the angle of inclination of the ladder. The length of the ladder,
i.e. the span between the attachment to the deck and the lower platform, is limited
by the loads for which the ladder is constructed. In modern ships with a very high
free board, such as 20 meters or more, it is of course desirable to have a long ladder,
but this also means that the ladder must be of very sturdy construction in order to
withstand the high loads which may be encountered.
[0003] In accomodation ladders intended to be used only at a quay and not for such purposes
as pilot's embarkation out at sea, it is previously known to use ladder portions which
are telescopically displaceable relative to each other, such as shown for instance
in the British patent specification GB-A-1236166 and in US-A-2448335.
[0004] It is not possible to combine the two above- mentioned designs for the reason that
the telescoping movement of the ladder can not be synchronized with the raising and
lowering of the lower platform and the maintenance thereof in a horizontal position.
Furthermore it is not possible to have two independent winch-and- wire systems for
operating the platform and for operating the telescoping ladder, respectively, since
it would not be possible to operate two such systems together with such accuracy as
to avoid that one of the systems is working at a faster rate than the other one.
[0005] In view of these difficulties it has not been possible to provide telescopic ladders
with so called pilot platforms and at the same time maintaining a synchronized operation.
Instead, separate structures have been used (one on each side of the ship) of a rather
expensive and special design, necessitating maintenance and stow away space arid also
occupying extra deck space.
The object and essential characteristics of the invention
[0006] The object of the invention is to provide a telescopic accomodation ladder which
may be used as an embarkation device in port and also for taking aboard pilots or
other persons at sea, for which purpose the platform is supplemented with a pilot
ladder in a manner known per se. The previously known telescopic ladder which is relatively
easily damaged due to its length has to be capable of positively maintaining the outer
platform in a "horizontal" position to secure that the pilot ladder is hanging perpendicularly,
since any skewing of the pilot ladder is detrimental and causes peril to anyone climbing
the ladder. This necessitates a good control of the mutual displacement of the ladder
portions, this telescoping movement having to be very well coordinated with the lowering
and raising of the outer platform. Furthermore the arrangement should be of simple
and reliable design and should not complicate the operations of swinging the ladder
in over the deck and stowing the same on deck.
[0007] This has been attained in a device described by way of introduction, in that at least
one of the wires supporting said second platform is arranged to extend via the platform
to said first portion of the ladder, i.e. that portion which is not longitudinally
displaceable.
Description of the drawings
[0008] The invention will be more closely described herebelow with reference to embodiments
shown in the accompanying drawings. Fig. 1 is a perspective view of a portion of an
embarkation device,
[0009] Fig. 2 is a diagrammatic view in perspective showing one embodiment of the device
according to the invention, and Fig. 3 shows a second embodiment.
Description of embodiments.
[0010] On the deck of the ship there is mounted a first platform 1 which is pivoted on a
shaft 2 extending alongships. The shaft 2 is interconnected with swingable davit arms
3 and 4.
[0011] To the first platform 1 there is pivotally connected a ladder 5 which comprises an
upper, first portion 6 which is pivoted to the upper platform 1 and a lower, second
portion 7 which is telescopically displaceable relative to the first portion 6. Only
the side rails of the two ladder portions are shown, the ladder steps being omitted
for the sake of clarity. To the lower end of the moveable portion 7 there is pivotally
connected a second platform 8 which is supported by two wires 9, 10.
[0012] As will appear from fig. 1, the second platform 8 has an entry and exit opening 11
surrounded by a rail 12 which facilitates comfortable passage through the opening
11. A pilot ladder 13 is connected to the platform 8 adjacent the opening 11 and on
that side which faces the ship's side.
[0013] In the embodiment illustrated in fig. 2 the wires 9 and 10 extend from a winch (not
shown) via pulleys on the davit arms 3 and 4, respectively, to pulleys at the corners
of the platform 8 and further around pulleys at the lower end of the upper ladder
portion 6 back to the platform 8, and are attached to the davit arms 3 and 4, respectively.
More specifically, the wire 9 extends via the davit arm 3 to a pulley 14 at the end
of the platform 8 facing away from the ladder 5, and further along the outer side
of the platform around a further pulley 15 at the end of the platform facing the ladder,
and from there below or along the side of the moveable ladder portion 7, around a
pulley 18 at the lower end of the upper ladder portion, and via further pulleys 16
and 17 on the platform 8 along the inner side thereof and back to the davit arm 3
to which the wire is attached. The second wire 10 extends via pulleys on the davit
arm 4 to the pulley 16 at the end of the platform 8 facing the ladder 5 and further
below or along the side of the moveable ladder portion 7, around pulleys 19 and 20
at the lower end of the upper ladder portion 6, and back to the platform 8 and via
the pulley 15 up to the davit arm 4 to which the wire is attached.
[0014] The ladder 5 is connected to the davit arm 4 by means of a support wire 21 of a fixed
length. The support wire extends from an attachment point on the davit arm 4 around
a pulley 22 at the lower end of the upper ladder portion 6, and to the upper end of
the moveable ladder portion 7 around pulleys or wire guides 24 and 25 at the respective
corners thereof, and back to the lower end of the upper ladder portion 6 at the opposite
side thereof and via a pulley 23 up to an attachment point on the davit arm 4. Of
course, it is also possible to have two support wires 21 which are attached to the
upper end of the moveable ladder portion 7 instead of extending around the pulleys
24, 25. When the wires 9 and 10 are paid out, the ladder 5 will be swung downwardly,
pivoting around the pivot shafts at the platforms 1 and 8, respectively. Independently
of the inclination of the ladder 5, the platform 8 will always be maintained in a
horizontal position by the wires 9 and 10. The moveable ladder portion 7 will be displaced
outwardly relative to the upper ladder portion 6 by gravity under control by the wire
21. Any uncontrolled extension of the moveable ladder portion 6 will be prevented
by the wires 9 and 10 which extend via the lower end of the upper ladder portion 6
and thereby prevents an increase of the distance between the platform 8 and the lower
end of the upper ladder portion 6. Instead, the displacement of the moveable ladder
portion 7 will be well coordinated with the lowering movement of the platform 8. At
the same time, the two ladder portions 6 and 7 are prevented from gliding apart.
[0015] When the platform 8 is raised, the wires 9 and 10 extending via the moveable ladder
portion 6 will contribute to the telescopic contraction of the ladder.
[0016] When the ladder 5 and the platform 8 have been raised to the level of the deck, they
are swung around the shaft 2 into the stowaway position, so that they will be situated
onboard inside of the railing.
[0017] As previously mentioned, the length of the support wire 21 is fixed, and as the distance
between the davit 4 and the pulleys 22 and 23 at the lower end of the upper ladder
portion 6 is increased, the distance will decrease between the pulleys (alternatively
the attachment points) 24, 25 at the upper end of the moveable ladder portion 7 and
the pulleys 22, 23 at the lower end of the upper ladder portion 6. In this manner,
the ladder 5 will be constantly supported at its middle portion. Furthermore, any
uncontrolled extension of the moveable ladder portion 7 will be counteracted.
[0018] The embodiment shown in Fig. 2 differs from the embodiment described hereinbefore
in that there is provided an extra davit arm 26 to which the support wire 18 is attached.
In the same manner as the two davit arms 3 and 4, the davit arm 26 is arranged on
the shaft 2. Also, the extension of the wires differs somewhat from the embodiment
illustrated in Fig. 1.
[0019] The wire 9 extends from the winch via the davit arm 3 to the pulley 14 at the end
of the platform 8 facing away from ladder 5, and via a further pulley 27 to the opposite
corner of the portion of the platform 8 facing the ladder 5 and via pulleys 28 and
17 back up to the davit arm 3, around a pulley provided below said davit arm and further
below the davit arm 4 and to a pulley provided below the davit arm 26, from where
the wire extends to the lower end of the upper ladder portion 6 and via pulleys provided
side by side with the pulleys 22, 19 and 20, 23 back up to the davit arm 26 to which
it is secured.
[0020] The wire 10 extends from the winch via the davit arm 4 to the pulley 16 at the end
of the platform 8 facing the ladder 5 and further below the moveable ladder portion
7 around the pulley 18 at the lower end of the upper ladder portion 6, back to the
platform and via the pulley 15 up to the davit arm 4 to which it is secured.
[0021] The support wire 18 extends below the moveable ladder portion 7 via a further pulley
29 arranged at the lower end of the upper ladder portion 6.
[0022] Other wire arrangements than those described above are conceivable within the scope
of the claims. It would for instance be possible to have only one of the wires 9 and
10 extending via the upper ladder portion 6, whereas the second wire would extend
from the davit arm to the platform 8 and back to the davit arm.
[0023] The device is not limited to the use of taking aboard people at sea, but can be used
with the same advantages as a conventional accomodation ladder, in which case the
second platform 8 is placed upon the quay.
1. An accomodation ladder for ships and of the kind comprising a telescopic ladder
(5) having a first portion (6) which is pivotally connected to a first platform (1)
or the like connected to the deck of the ship and a second portion (7) which is telescopically
displaceable relative to said first portion and at the free end of which there is
pivotally carried a second platform (8) which is supported by at least one davit (3,
4) or the like via a wire arrangement (9, 10) which is adapted to maintain said second
platform (8) in a position substantially parallel to the deck of the ship regardless
of the inclination of said ladder portions (6, 7), and wherein at least one support
wire (21) is adapted to support the ladder and control the displacement of said second
portion (7) relative to said first portion (6), characterized in that at least one
of the wires (9, 10) supporting said second platform (8) extends via the platform
(8) to said first portion (6) of the ladder (5).
2. An accomodation ladder as claimed in claim 1, characterized in that at least one
of said wires (9, 10) extends from. a davit (3) around a pulley (14) at one corner
of said second platform (8), around at least one pulley (18) on said first portion
(6) of the ladder, back to said platform and around a pulley (17) to a davit.
3. An accomodation ladder as claimed in claim 1 or 2, characterized in that at least
one of said wires (9, 10) extends from a davit (3, 4) to one corner of said second
platform (8) and via pulleys below said platform and up to said davit, via further
pulleys to another davit (26) and down to said first portion (6) of the ladder (5)
and via pulleys on said first portion up to a davit (3, 4, 26).
1. Fallreep-Treppe für Schiffe bestehend aus einer teleskopischen Treppe (5), mit
einem ersten Abschnitt (6), der an eine erste Plattform (1) oder dergleichen, angelenkt
ist, die mit dem Deck des Schiffes verbunden ist und einem zweiten Abschnitt (7),
der teleskopisch gegenüber dem ersten Abschnitt verschiebbar ist, sowie an dem freien
Ende drehbar eine zweite Plattform (8) trägt, die von mindestens einem Davit (3, 4)
oder dergleichen über eine Seilanordnung (9, 10) getragen wird, die unabhängig von
der Niegungslage der Treppenabschnitte (6, 7) die zweite Plattform (8) in einer mit
dem Deck des Schiffes hauptsächlich parallelen Stellung hält, wobei mindestens ein
Tragseil (21) vorgesehen ist die Treppe zu tragen und die Verschiebungsbewegung des
zweiten Abschnittes (7) gegenüber dem ersten Abschnitt (6) zu kontrollieren dadurch
gekennzeichnet, dass mindestens eines der Seile (9, 10), die die zweite Plattform
(8) tragen, sich über die Plattform (8) hinaus zum ersten Abschnitt (6) der Treppe
(5) erstrecken.
2. Fallreep-Treppe nach Anspruch 1, dadurch gekennzeichnet, dass mindestens eines
der erwähnten Seile (9, 10) sich von einem Davit (3) über eine Rolle (14) an der einen
Ecke der zweiten Plattform (8), um mindestens eine Rolle (18) am ersten Abschnitt
(6) der Treppe herum, zurück zu der erwähnten Plattform und über eine Rolle (17) an
einem Davit erstreckt.
3. Fallreep-Treppe nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass mindestens
eines der erwähnten Seile (9, 10) sich von einem Davit (3, 4) zu einer Ecke der zweiten
Plattform (8), und über Rollen unterhalb dieser Plattform und zurück zu dem Davit,
über weitere Rollen zu einem weiteren Davit (26) und abwärts zum ersten Abschnitt
(6) der Treppe (5), sowie über Rollen an dem ersten Abschnitt und zurück zu einem
Davit (3, 4, 26) erstreckt.
1. Une échelle de coupée pour bateaux du genre comprenant une échelle à coulisse (5)
comportant un premier tronçon (6) articulé sur une première plate-forme (1) ou analogue
reliée au pont du bateau et un second tronçon (7) déplaçable à coulissement par rapport
audit premier tronçon et portant articulée sur son extrémité libre une seconde plate-forme
(8) supportée par au moins un bossoir (3, 4) ou analogue par l'intermédiaire d'un
système de câbles (9, 10) qui est agencé pour maintenir ladit seconde plate-forme
(8) dans une position sensiblement parallèle au pont du bateau indépendamment de l'inclinaison
des tronçons d'échelle (6, 7), et dans lequel au moins un câble de support (21) est
conçu pour supporter l'échelle et commander le déplacement dudit second tronçon d'échelle
(7) par rapport audit premier tronçon (6), caractérisé en ce que le ou chaque câble
(9, 10) supportant ladite seconde plate-forme (8) s'étend en passant par la plate-forme
(8) jusqu'audit premier tronçon (6) de l'échelle (5).
2. Une échelle de coupée telle que revendiquée dans la revendication 1, caractérisée
en ce qu'au moins I:un desdits câbles (9, 10) part d'un bossoir (3), contourne une poulie (14) située
à un coin de ladite seconde plate-forme (8), contourne au moins une poulie (18) située
sur ledit premier tronçon (6) de l'échelle, revient à ladite plate-forme et rejoint
un bossoir en contournant une poulie (17).
3. Echelle de coupée telle que revendiquée dans la revendication 1 ou 2, caractérisée
en ce qu'un au moins desdits câbles (9, 10) va d'un bossoir (3, 4) à un coin de ladite
plate-forme (8), passe par des poulies situées sous ladite plate-forme et remonte
jusqu'audit bossoir, atteint en passant par d'autres poulies un autre bossoir (26),
descend jusqu'audit premier tronçon (6) de l'échelle (5) et remonte en passant par
des poulies portées par ledit premier tronçon jusqu'à un bossoir (3, 4, 26).