GB2250718A

GB2250718A - Filament dispensing arrangement

Info

Publication number: GB2250718A
Application number: GB8331480A
Authority: GB
Inventors: Michael John Cahill
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1982-11-27
Filing date: 1983-11-25
Publication date: 1992-06-17
Anticipated expiration: 2003-11-25
Also published as: GB2250718B

Abstract

A filament dispensing arrangement, for example for dispensing filament from a submarine to a wire-guided torpedo, includes a flexible hose 5 through which a filament 4 is dispensed and fluid supply means 8 which cause fluid to flow through the hose 5 thus assisting passage of the filament through the hose and also allowing the stiffness of the hose to be controlled by suitable selection of fluid flow rate and size of orifice 6. <IMAGE>

Description

FILAMENT DISPENSING ARRAGEMENTS This invention relates to filament dispensing arrangements and in particular, but not exclusively, to arrangements for dispensing wire from a submersible vehicle.

Such arrangements may be used when dispensing wire from a submarine to a wire-guided torpedo or for dispensing a wire to a submersible vehicle for monitoring the condition of the submersed parts of an oil rig.

When a wire-guided torpedo is launched from a parent vehicle the torpedo and parent vehicle may move a combined distance from the launch location of many kilometres. Part of the guidance wire is stored in the torpedo and is dispensed rearwardly therefrom as the torpedo travels to its destination, the remainder of the wire being stored on the parent vessel near the launch tube for the torpedo and being dispensed as the parent vessel moves from the location at which the torpedo was launched.

After the torpedo is launched, the parent vessel may perform various manoeuvres, possibly heading in the opposite direction to that in which the torpedo is travelling. In dispensing the wire from the parent vessel it has been the practice to provide a hose fixed to the parent vessel and to allow the wire to be drawn through the hose to attempt to avoid fouling of the wire with the propulsion or steerage means of the parent vessel during such manoeuvres. This apparatus and method previously adopted suffer from the following disadvantages.

Friction between the wire and hose may become excessive thus requiring a strong and consequently bulky wire.

If fouling of the wire with the parent vessel is to be avoided, the hose must have a "stand-off" capability to dispense the wire away from the body of the vessel and this has previously been achieved by using a stiff hose; but this stiffness is a disadvantage when the torpedo is moving in a direction offset to the axis of the free end of the hose because the wire rubs heavily on the walls of the hose. The provision of a stiff hose to give a stand-off capability therefore may increase friction between the wire and the hose.

The invention seeks to overcome these disadvantages and to provide a dispensing arrangement in which the friction between the dispensed wire and the hose is reduced yet which still allows a stand-off capability.

According to one aspect of this invention, there is provided a dispensing arrangement for dispensing a filament, for example wire, which arrangement includes a flexible tubular element through which the filament may be drawn from an inlet end thereof to an outlet end thereof, and fluid supply means operable to cause fluid to flow through said tubular element, said fluid acting to assist passage of the filament through the tubular element.

This arrangement allows the friction load on the filament as it is drawn through the tubular element to be reduced. It is thought that this is caused by providing a hydrodynamic effect which reduces contact of the filament with the bore of the tubular element. Additionally, the fluid supply means causes and increased internal pressure acting in the tubular element, thereby stiffening it.

Preferably, the arrangement includes fluid supply control means arranged to control the flow of fluid through the tubular element thereby to allow the stiffness of the tubular element to be maintained at a predetermined degree.

In one arrangement, the fluid supply means comprise a pump delivering fluid to the inlet end of the tubular element. In this instance, the control means may include a by-pass circuit and associated valve means operable to allow the mass flow delivered to the tubular element to be varied to achieve the required degree of stiffness.

At its end remote from the fluid supply means, the tubular element may include orifice means of reduced internal cross-section as compared to that of said tubular element, said orifice means serving to maintain the internal pressure acting in the tubular element and also serving to at least reduce contact of the filament with the wall of the tubular element at that end region.

Preferably, said dispensing arrangement includes storage means adapted to store the filament and the tubular element each in a compact (e.g. coiled) condition.

Further orifice means may be provided within the tubular element at intervals along the length thereof each sized and located so as to produce a pre-determined pressure distribution along the length thereof, thereby to impart a selected stiffness characteristic to the tubular element.

In another aspect of this invention, there is provided a dispensing arrangement for dispensing an elongate flexible signal-carrying element from a water-based vehicle, said arrangement including storage means for storing said flexible element, a flexible tubular element attached at one end to said vehicle and through which said flexible element may be dispensed, and fluid supply means operable to cause fluid to flow through said tubular element thereby to assist passage of the filament through the tubular element.

The fluid is preferably water and a low drag additive may be mixed therewith.

Further aspects will become apparent from the following exemplary description of a filament dispensing arrangement with reference to the accompanying drawing which is a general schematic representation of a filament dispensing arrangement.

The filament dispensing arrangement illustrated is for use in dispensing a wire from a submarine to a torpedo to allow the torpedo to be guided under command signals sent from the submarine along the wire. The dispensing arrangement would be located in the in-board end region of the torpedo launch tube and is illustrated in a deployed condition.

Referring to the drawing, there is shown a torpedo launch tube 1 at the inboard end of which is situated a hollow storage drum 2 in which is housed a core-less bobbin 3 of wire 4. An elongate flexible hose 5 formed of hose reinforced by POTEE fibres or metal wires is attached to the inboard end of the drum 2 and passes through the drum thence out of the launch tube to trail from the submarine. In use the wire 4 is drawn through the hose 5, unravelling from the interior of bobbin 3. An orifice element 6 is provided at the end of the hose remote from its attachment to drum 5, having an internal diameter substantially less than the internal diameter of hose 5. The orifice element is preferably made of a low friction material such as Delrin (an acetal resin).At the inboard end of the drum 2 adjacent the hose 5 is provided an inlet port 7 supplied with fluid by pump 8 via pipe 9. The pump is fitted with a regulatable by-pass circuit 10 to allow the flow of fluid supplied to drum 2 and thence along hose 5 to be adjusted as required. The amount of fluid flow supplied to the drum 2, and the size of orifice element 6 are selected so that in one aspect the flow through the hose 5 is sufficient significantly to reduce friction between the hose 5 and wire 4 as the wire is dispensed and in another aspect so that the pressure within hose 5 is sufficient to impart to the hose sufficient stiffness to provide a stand-off capability.

The flow of fluid through the hose 5 may be increased or decreased to suit the velocity of wire dispensing required.

The orifice element 6 is an optional feature, but when present, serves both to regulate the internal pressure in the hose and also to hold the wire away from the wall of the hose. Other orifice elements or guides may be placed along the length of the hose to provide a predetermined pressure distribution thereby to generate a particular flexibility characteristic. The length of the hose is typically about 50m.

Prior to launch of a torpedo, the hose 5 may be coiled around the bobbin 3 and releasably attached by means of a shear pin or similar arrangement to the rear end of the torpedo. On launch of the torpedo, the hose 5 is drawn out to its full extent from the drum 2 whereupon it is released from the torpedo whereafter wire 4 is drawn through the hose assisted by fluid supplied by pump 8.

The fluid employed would be sea water with which a low-drag additive had been mixed.

The above described arrangement allows the use of a thinner wire, thus increasing the possible range of guidance and reducing the volume of wire that has to be employed.

In the arrangement, fluid is forced through the hose 5 to assist the passage of the wire through the hose by skin friction, whilst serving to lubricate the areas where contact would otherwise occur between wire and hose.

Claims

1. A dispensing arrangement for dispensing a filament, which arrangement includes a flexible tubular element through which the filament may be drawn from an inlet end therof to an outlet end thereof and fluid supply means operable to cause fluid to flow through said tubular element, said fluid acting to assist passage of said filament through the tubular element.

2. An arrangement according to claim 1, which further includes fluid supply control means adapted to control the flow of fluid through the tubular element.

3. An arrangement according to claim 1 or claim 2, wherein the fluid supply means comprise a pump delivering fluid to the inlet end of the tubular element.

4. An arrangement according to any of the preceeding claims, wherein the outlet end of the tubular element includes orifice means of reduced internal cross-section as compared to that of the flexible tubular element, said orifice means serving to maintain the internal pressure acting in the tubular element and also serving to at least reduce contact of the filament with the internal wall of the tubular element adjacent said outlet end region.

5. A dispensing arrangement according to any of the preceeding claims, which further includes storage means adapted to store the filament and the tubular element each in a compact condition.

6. A dispensing arrangement according to claim 4, wherein further orifice are provided within the tubular element spaced along the length thereof, each sized so as to produce a predetermined pressure distribution along the length thereof thereby to impart a selected stiffness characteristic to the tubular element.

7. A dispensing arrangement for dispensing an elongate flexible signal-carrying element from a water-based vehicle, said arrangement including storage means for storing said flexible element, a flexible tubular element attached at one end to said vehicle and through which said flexible element - be dispensed, and fluid supply means operable to caul fluid to flow through said tubular element, ;thereby to assist passage of the filament throught the tubular element.

8. A dispensing arrangement according to claim 7, wherein said fluid comprises water with a low drag additive added thereto.

9. A dispensing arrangement substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawing.

Amendments to the clans have been ffled as follows 5. A dispensing arrangement according to any of the preceding claims, which further includes storage means adapted to store the filament and the tubular element each in a compact condition.

6. A dispensing arrangement according to Claim 4.

wherein further orifices are provided within the tubular element spaced along the length thereof, each sized and located so as to produce a predetermined pressure distribution along the length thereof thereby to impart a selected stiffness characteristic to the tubular element.

7. A dispensing arrangement for dispensing an elongate flexible signal-carrying element from a water-based vehicle, said arrangement including storage means for storing said flexible element. a flexible tubular element attached at one end to said vehicle and through which said flexible element may be dispensed, and fluid supply means operable to cause fluid to flow through said tubular element, thereby to assist passage of the filament through the tubular element.

8. A dispensing arrangement according to Claim 7, wherein said fluid comprises water with a low drag additive mixed therewith.