CABLE SEPARATION APPARATUS

APPAREILS DE SEPARATION DES CABLES

English Abstract

The invention relates to a cable separation apparatus having the following features: - the apparatus has a fluid-filled cylinder (10), with a closure cover (11), for connection to a first cable section, as well as - a piston (20), which is guided in the cylinder (10) and has a piston rod (23), for connection to a second cable section, with the piston (20) having a hole (22) as a flow channel for the fluid so as to allow the fluid to be exchanged for the two cylinder subareas (15, 16) on both sides of the piston (20), and - a sealing device (13, 14) for fluid-tight connection of the cylinder (10) and closure cover (11), and - one or more release cables (26) which is or are connected to the piston rod (23) and opens the sealing device (13, 14) as soon as the piston (20) has moved back through a predetermined distance under the tensile force into the cable sections, such that the two cable sections are separated from one another.

French Abstract

Linvention concerne un appareil de séparation de câbles avec les caractéristiques suivantes : - lappareil possède un cylindre rempli dun fluide (10), avec un couvercle de fermeture (11), pour raccordement à une première section de câble, ainsi que - un piston (20) qui est guidé dans le cylindre (10) et possède une tige de piston (23) pour raccordement à une seconde section de câble, avec le piston (20) doté dun trou (22) comme un canal découlement pour le fluide de manière à permettre au fluide dêtre échangé pour les sous-zones du cylindre (15, 16) sur les deux côtés du piston (20), et - un dispositif détanchéité (13, 14) pour un raccordement étanche du cylindre (10) et du couvercle de fermeture (11), et - un ou plusieurs câbles de déverrouillage (26) qui est/sont raccordé(s) à la tige de piston et ouvre(nt) le dispositif détanchéité (13, 14) dès que le piston (20) revient sur une distance prédéterminée en raison de la force de traction dans les sections des câbles, de sorte que les deux sections de câbles sont séparées lune de lautre.

Claims

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Claims
1. Cable separation apparatus comprising:
- a fluid-filled cylinder (10), with a closure cover
(11), for connection to a first cable section,
- a piston (20) guided in the cylinder (10) and
having a piston rod (23) for connection to a
second cable section, the piston (20) having a
hole (22) as a flow channel for the fluid so as to
allow the fluid to be exchanged between two
cylinder subareas (15, 16) on both sides of the
piston (20), and
- a sealing device (13, 14) for fluid-tight
connection of the cylinder (10) and closure cover
(11), and
- one or more release cables (26) connected to the
piston rod (23) and opening the sealing device
(13, 14) as soon as the piston (20) has moved back
through a predetermined distance under a tensile
force into the cable sections, such that the two
cable sections are separated from one another.
2. Cable separation apparatus according to Claim 1,
wherein the sealing device (13, 14) comprises:
- a plurality of sealing segments (13) which
surround a circumferential bead-like widened area
(12) on the cylinder (10) and the closure cover
(11), and
- a sealing ring (14) which surrounds the sealing
segments (13) and to which the release cable or
cables (26) is or are attached.

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3. Cable separation apparatus according to Claim 1 or
2, wherein a cable connecting body (25), to which the
release cable or cables (26) is or are attached, is
provided at the end of the piston rod (23).
4. Cable separation apparatus according to any one of
claims 1 to 3, wherein a bursting disc (21) is provided
and blocks the flow channel (22) when in a sound state.
5. Cable separation apparatus according to claim 2,
wherein the cylinder (10) and the closure cover (11)
are composed of steel, and the sealing segments (13)
are composed of bronze.

Description

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Cable separation apparatus
The invention relates to a cable separation apparatus
whose purpose is to separate a cable, a line or some
other structure in the form of a strand (referred to in
general in the following text as a cable) in a specific
situation. Cable separation apparatuses such as these
are used in particular in parachute or paraglider
systems.
Cap apparatuses are normally used for this purpose
which cut through the cable, possibly after a defined
delay time after the initiation pulse, by means of a
cutting apparatus, for example DE 102 30 535 Al. By way
of example, pyrotechnic capping apparatuses are known
which are activated by a pyrotechnic propellant charge.
Known capping apparatuses such as these are relatively
heavy, of relatively large volume, and require an
external drive. In addition, in the case of pyrotechnic
capping apparatuses, hazardous substances are used for
which stringent official regulations must be complied
with when handling them.
The object of the invention is therefore to provide a
cable separation apparatus which makes it possible to
overcome the abovementioned disadvantages of the known
capping apparatuses.
This object is achieved by a cable separation apparatus
comprising:
- a fluid-
filled cylinder, with a closure cover, for
connection to a first cable section,

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- a piston guided in the cylinder and having a
piston rod for connection to a second cable
section, the piston having a hole as a flow
channel for the fluid so as to allow the fluid to
be exchanged between two cylinder subareas on both
sides of the piston, and
- a sealing device for fluid-tight connection of the
cylinder and closure cover, and
- one or more release cables connected to the piston
rod and opening the sealing device as soon as the
piston has moved back through a predetermined
distance under a tensile force into the cable
sections, such that the two cable sections are
separated from one another.

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The cable separation apparatus according to the
invention is fitted into the cable to be separated. The
separation process takes place by the cable separation
apparatus breaking up into two parts at the desired
time.
The apparatus according to the invention makes it
possible to set the delay between the initiation pulse
and the separation. This is physically small,
lightweight and compact, and has no pyrotechnics.
The invention will be described using one exemplary
embodiment and with reference to a figure which shows
an apparatus according to the invention in the form of
an axial cross section, shortly before separation.
The separation apparatus according to the invention
comprises a cylinder 10 and a piston 20 as the main
parts. These are each intended to be connected to the
two sections of the cable into which the cable breaks
up after separation. Holes 1, 2 are provided for
connection.
The piston 20 is inserted in the cylinder 10 and splits
it into two subareas 15, 16, which are filled with an
incompressible liquid. On one side, the cylinder 10 is
closed by a closure cover 11 which seals the cylinder.
The piston 20 has a hole 22 as a flow channel for the
liquid, in order to allow liquid to be exchanged
between the two cylinder subareas 15, 16 in front of
and behind the piston 20.
A bursting disc 21 is advantageously fitted in the
piston 20, and is arranged in front of the flow channel
22. In the sound state, it seals the flow channel 22.
This prevents the piston 20 from being moved
prematurely from its initial position, for example if

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tension is applied to the cable during handling or
packing.
A piston rod 23 runs in a hole in the closure cover 11.
A cable connecting body 25 is located at each end
remote from the cylinder. The piston 20 and cable
connecting body 25 are firmly connected to one another
via the piston rod 23.
The cylinder 10 and closure cover 11 are held by a
sealing device having a plurality of sealing segments
13. In this embodiment, there are three and only three
sealing elements 13 distributed over the circumference
of the cylinder (only two of these can be seen in the
figure). The sealing elements 13 surround a bead-like
widened area 12 on the closure cover 11 and cylinder 10
and are secured by a circumferential outer sealing ring
14, which holds them in position.
The sealing ring 14 is attached to the cable connecting
body 25 by initiation cables 26. Overall, there are
three initiation cables 26 in the illustrated
embodiment, which are distributed uniformly over the
circumference of the sealing ring 14. The length of the
initiation cable 26 is matched to the length of the
movement distance of the piston 20 in the cylinder 10.
At the start of the separation process, the piston 20
has been inserted entirely into the cylinder 10. The
initiation cable 26 is slack, without any stress, in
this piston position. The disconnection pulse
originates from a tensile load shock in the cable
which, for example, may be the opening shock when a
parachute opens. The force of this opening shock causes
the bursting disc 21 to burst, and the force which is
still applied to the cable after the opening shock (=
load on the parachute) pulls the piston 20 out of the
cylinder 10 by liquid being forced through the hole

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that is created in the bursting disc 21 and through the
hole 22 in the piston 20 located underneath it out of
the first subarea 15 into the second subarea 16 in the
cylinder 10. In consequence, the piston 20 in the
cylinder 10 moves slowly out of the cylinder 10.
When, as shown in the figure, the piston 20 reaches the
end area of its movement distance in the cylinder 10,
tension is applied to the initiation cables 26 and they
pull the sealing ring 14 off the sealing segments 13,
which are forced apart from one another because of the
obliquely positioned bead 12 on the cylinder 10 and the
closure cover 11, and the internal higher pressure in
the subarea 15. In consequence, the closure cover 11 is
first of all separated from the cylinder 10 and the
piston 20 leaves the cylinder 10. Together with the
piston rod 23, the cable connecting body 25, the
initiation cables 26 and the sealing ring 14, the
piston 20 hangs freely at the end of the connected
cable section. The cylinder 10 remains at the end of
the other cable section. The cable is thus separated.
The length of the movement distance of the piston 20 in
the cylinder, the diameter of the hole 22 in the piston
20 and the viscosity of the liquid govern the delay
time between the initiation pulse and separation of the
cable.
In order to avoid the loss of components during
separation, the sealing segments 14 can be attached to
the cylinder 10 by means of locking wires 3, for
example by means of a clamping apparatus.
In order to avoid jamming between the bead 12 on the
cylinder 10 and the closure cover 11 on one side and
the sealing segments 14 on the other side, the
materials can be matched to one another. By way of
example, the combination of steel (for the cylinder 10

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and the closure cover 11) and a bronze alloy (for the
sealing elements 13) may be particularly suitable.

Representative Drawing