[0001] The present invention relates to a release mechanism for releasing maritime rescue
equipment, preferrably being openable containers comprising inflatable lifeboats.
Such containers are, while being fastened to suitable support stands on board the
relevant ships, by means of claspable straps releasably retained on the support stands
while having one of the ends of the straps permanently fastened onto the support stands
and having the other ends of the straps releasably fastened to the support stands
in a generally standardized manner involving a so-called release hook being hooked
into a hole within the support stand. The release hook comprises an eye portion adapted
to stay in connection with a back-bend end of the straps and a protruding base portion
of the hook with a free end portion extending relatively far backwards which at the
end comprises a retaining protrusion for the retaining of an anchoring ring encirculating
the base portion of the hook and the respective free end portion. The free hook end
portion can be let through the retaining hole within the support stand og thereafter
be locked against pull-out by letting the locking ring down over the retaining protusion
on the free end of the hook.
[0002] The backwards protruding free end is resiliently depressible into the base portion
of the hook so that, to manually achieve a release of the connection provided by the
hook, the hook can be sufficiently compressed to provide a releasing of the locking
ring from the retaining protrusion and thereafter flip and retract the hook from its
grip in the hole in the support stand thus releasing the floatable container whereby
a connection to the ship still is in general maintained by means of a lifeline which
at last may be cut by means of release means or a knife having been installed in the
liferaft.
[0003] In the later years a release device has been added to this traditionally embodied
release system which automatically is able to break the retaining hook connection
whenever a water pressure corresponding to submersion down to a depth of a few meters
below the surface of the sea. By means hereof it is safeguarded that the liferaft
container in case of an actual shipwreck is going to be released in time so that the
liferaft still can also be of use in case a manual release has not been carried out.
As an example an embodiment of such a hydrostatic release device is disclosed through
the Danish industrial pattern No. DK-BR-1998 00279.
[0004] It has been found that the simplest way of employing the hydrostatic release device
is so that the two main members which may be mutually locked or released are mounted
respectively through a fixed connection to the support stand and in shape of a releasable
member being provided with the hole which receives the aforementioned release hook
whereby it is mandatory that long time before an activation of the hydrostatic release
device, as caused by a factual sinking of the ship, may take place, it is possible
manually to provide a release.
[0005] The hydrostatic release device thus provides an added safety without deviation from
the safety provided by means of the aforementioned, in general employed release hooks.
[0006] Through the existence of the present invention it has been found that the traditionally
provided release hooks present problems of safety with regard to the easiness of release
which is being required of them. Thus, when applying an initially tight tensioned
strap, in case of exposure of the strap to an increased level of humidity, the tension
of the strap is further augmented, and in that case a correspondingly strong tension
within the strap provides a pulling in the release hook whereby the free end portion
of the release hook is forced to an elastic pivoting away from the main stem of the
hook thus resulting in a so strongly augmented outwards tensioning within the aforementioned
locking ring that it becomes difficult to release it through a manual squeezing of
the release hook. Furthermore, the release hook has to be released from the retaining
gripping by being bent outwards to achieve a transverse translation of the external
hook portion away from the retaining hole, and this necessary bending outwards of
the hook is made difficult to perform due to an increased pulling within the eye-end
of the hook. Therefore, by means of the present invention a changed standard for the
fastening of the releasable strap end has to be provided for so that a fairly easy
provided releasing is safeguarded independent on the size of the tension within the
strap. A further purpose according to the invention moreover is to depict an embodiment
of the hydrostativ release device enabling it to function as a the manual release
means.
[0007] According to the invention, the coupling portion of the hydrostatic release device
being adapted to be coupled onto the strap through the aforementioned release hook
is bracelike shaped in such a manner as to make it directly or releasably couplable
to the eyelet or to the loop of the strap while employing a releasable coupling beam
which by means of a transverse locking-split-pin or a corresponding manually pull-out
locking means is locked against any unintended release from the bracelike portion.
By means hereof, the aforementioned coupling portion of the hydrostatic release device
may function as well as an automatically releasable portion or as a strap retaining
means making a manual releasing of the strap possible.
[0008] By means of the aforementioned mounting of the strap on a coupling portion which
is locked against being pulled-away from the aforementioned bracelike portion the
pulling force from a tensioned strap is being received by the bracelike portion and
by the coupling beam extending through the eyelet of the strap, and the easiness with
which the aforementioned locking-split-pin can be pulled-out from the locking position
it occupies is only influenced by the larger or minor value of the friction against
pull-out depending upon the pulling force within the strap. A locking-split-pin which
is provided with a rigid strap ring will in practice easily lend itself to be manually
pulled-out even in case of a strong-tensioned coupling connection, thus a releasing
will more easily be brought to take place than while employing the aforementioned
release hooks.
[0009] Hydrostatic release devices may be activated in different manners than by employing
water pressure, different manners to be mentioned are thus: By means of water contact,
by means of electric signals, by means of radio signals, by means of air-/gas pressure,
by means of vacuum, but also other manners of releasing are possible as well as combinations
hereof all dependent upon the various conditions.
[0010] Embodiments according to the invention are specified in more details as follows under
reference to the drawing, wherein:
Fig. 1 in the perspective illustrates a conventionally employed supporting device
for a life raft container, and
fig. 2 correspondingly illustrates a release coupling according to the invention.
[0011] In Fig. 1 of the drawing a liferaft container 2 is illustrated which is arranged
supported in a support stand 4 and is fastened to the support stand by means of an
upper strap 6 which connectingly extends down to a retaining eye 8 of a release hook
10 which comprises an upwards extending fork branch 12 which is let through a below
arranged retaining hole comprised in a part 14 of a coupling. This part in itself
forms a releasable part of a hydrostatic release coupling device 16 which moreover
is coupled onto a fixed bottom part of the support stand 4. The strap 6 thus lends
itself to be released as well manually by being taken off the release hook 10 and
away from the element 14 as automatically through a releasing of the element 14 itself.
[0012] According to the embodiment illustrated in Fig. 2 the upper end of the part 14 of
the coupling is shaped as a bracelike member 18 of which one branch comprises an outwards
extending protrusion 20 while the other branch exhibits a hole for receiving a locking
split-pin 22. To the bracelike member 18 belongs a transverse beam 24 which at the
ends comprises eyelets, adapted to be put down over the ends of the branches, and
between them a straight beam portion so that the transverse beam 24 is adapted to
be able to be inserted through an eyeshaped free end of the strap or through the loop
of the strap 6 and thereupon can be mounted in place on the branch ends of the bracelike
member 18 with inclusion of the accompanying locking provided in part through the
providable gripping connection with the locking protrusion 20 and in part through
the mounting-in-place of the locking split-pin 22.
[0013] Hereafter, the part 14 of the coupling will function as being automatically releasable
just as formerly provided, but the strap 6 itself is now manually directly releasable
away from the part 14 of the coupling, i.e. performed by a simple pulling-out of the
locking split-pin 22 through the employing of a pull-eyelet 26 provided on it.
[0014] It is not excluded that other usable manners providing releasable fastening of the
end of the strap directly onto the part 14 of the coupling may be found, but, it will
however after all be attained, that the release hook 10 which it is difficult to handle
can be omitted and which release hook, it in practice is required, has to be mounted
in place on the strap only by the producer who delivers the liferaft container 2 itself.
[0015] It should be noticed, that the illustrated embodied device according to the invention
furthermore presents the advantage that due to the achieved simplified embodiment
the risk for an erroneous mounting of the unit might take place is minimized, because
the embodiment in itself guides how the single relevant items belonging to the coupling
system have to be connected together. This feature forms an important aspect with
regard to safety.
1. Release mechanism to the releasing of maritime rescue equipment, preferrably openable
containers for inflatable lifeboats, being of the type which comprises a manually
openable gripping connection between a support stand connected part and an achoring
part being mounted onto an eyelet at the end of a holding strap which serves to the
fastening of the equipment, characterized in that the support stand connected part terminates in an open retaining fork with an internal
width which substantially corresponds to the width of the strap, which strap comprises
branch ends being shaped with retaining means for a releasable anchoring member extending
between these branch ends thereby forming the said anchoring means, and which retaining
means are comprised of respectively a fixed pulling-away-abutment (20) and a with
a pull-handle (26) provided transverse locking-split-pin (22) inserted in a hole in
the respective branch end.
2. Release mechanism according to claim 1 whereby the to the support stand connected
part is comprised within a hydrostatic automatic release device characterized in that the said retaining fork is shaped as an integral member arranged directly at the
end of the releasable part of the automatic release device.