WO1991013824A1

WO1991013824A1 - Spooler system

Info

Publication number: WO1991013824A1
Application number: PCT/GB1991/000362
Authority: WO
Inventors: Simon Thomas Nicholls; John Greenleaf Kellett; Adrian Frederick Fulcher
Original assignee: British Telecommunications Public Limited Company
Priority date: 1990-03-08
Filing date: 1991-03-07
Publication date: 1991-09-19
Also published as: GB9005188D0; AU7547591A

Abstract

A spooler system for maintaining a line on a reel (8) under tension to prevent slack. The reel (8) is mounted on a rotary member such as casing (1) that is provided with a plurality of vanes (3) onto which jets (6, 7) of air are directed to induce rotation so as to maintain tension and to wind back any slack onto the reel.

Description

SPOOLER SYSTEM

This invention relates to a spooler system for controlling tension, and particularly to a spooler system which retains or rewinds a line such as a cable or filament on a reel under tension to avoid slack.

In a situation where a line is being unwound from its holder or reel during use, excess line is frequently unwound and the slack is left trailing around the working area. For example, in a robot-operated assembly where the robot might carry out one task using the line, thus unwinding it from the reel, and then back-track to carry out a different task using the line, the excess line which was initially unwound will then be left trailing across the working area. This is an obviously undesirable situation, and it is rendered even more undesirable if the line comprises an optical fibre because tight bends that could inadvertently be formed in a slack line could well damage the optical fibres.

Optical fibre line, within the context of this invention may comprise ' bare' fibre, that is having only a primary coating, or it may comprise one or more fibres in a secondary coating or sheathing. Inadvertent bending of slack line or fibre may occur for example if a robot is used to install a line comprising optical fibres in elements of a system, and in order to reach one element the line is unwound and then the next element is closer to the reel. As the robot back-tracks or moves to the closer element, which could be a work station that has to be repeatedly visited between other elements to process the line, it would be very easy for the slack line to get pulled into kinks or loops of too tight a radius that wovild damage the fibre. The problem is particularly significant when handling optical fibres because, in view of the bend radius limitation, handling apparatus has to ensure that kinks and taut pulls where the

SUBSTI fibre exits from an element are not produced, and in consequence more slack tends to be provided.

In order to avoid undesirable excess line trailing round the working area, a spooler device may be provided such that the line can be readily unwound from its reel and any slack line can be continuously rewound under a tension which is effective but not high enough to damage the fibre as the robot moves.

However if such a device is held under tension by a helical spring there is a limit to the operative length of the spring, and therefore a limit to the length of line that can be rewound. A friction controlled spooler limits excess tension only. Furthermore, both these techniques may prove to be liable to cause too high a tension in the fibre, thus endangering the integrity of the fibre. A means of taking up excess line employing magnets or motors, for example, would be relatively complex and could cause inertia problems and subsequent damage.

According to the present invention there is provided a spooler system comprising a rotary member having a plurality of vanes and means for directing at least one jet of fluid onto the vanes to rotate the rotary member, the rotary member being adapted to provide a winding bias to a line on a reel.

Further according to the invention there is a method of providing a winding bias, the method comprising directing at least one jet of fluid onto vanes associated with a rotary member.

The invention will be described by way of example, with reference to the accompanying drawings, in which:

Figure 1 illustrates one embodiment of the invention; and

Figure 2 is a sectional view of a spooler according to the embodiment shown in Figure 1. Referring to Figures 1 and 2, a spooler 1 has a cylindrical casing 2 which is mounted for free rotation about its longitudinal axis. Conveniently the casing is disposed with the longitudinal axis of rotation vertical and the casing may be mounted on a roller bearing 9 to provide the rotatability. A plurality of inwardly directed vanes 3 are provided extending from the interior of the side wall of the casing, and a tube (not shown) conveys air under pressure to the centre of the casing where the air is then divided into two jets directed in substantially opposite directions towards the side walls of the casing. The air is divided, for example as shown, by the tube separating into two branches 4 and 5 or by a closed ended tube having two vents in the side wall. Two separate supplies - could alternatively be used. The two jets of air impinge on the vanes 3 generally in the directions indicated by arrows 6 and 7, the force of the air on the vanes causing rotation of the casing 2 about the longitudinal axis.

A passageway 10 is formed in the casing of the spooler passing through the centre of the top of the casing and out through the cylindrical side into a guide tube 12. A reel 8 of line on a fixed base 11 is attached to the spooler, preferably with the reel axis concentric with the axis of rotation of the spooler casing. Extension 18 from the fixed base allows this to be effected and also centralises the reel 8. The .free end of the line is passed through the guide tube and the spooler casing, and out through the top of the spooler, such that rotation of the spooler causes line to be unwound from or rewound onto the static reel 8. Thus the line is pulled off manually or otherwise via the spooler against the bias provided thereby. ^* The reel 8 itself does not rotate.

The air jets operating at a particular air pressure provide a constant bias which tends to rewind slack cable onto the reel. The air pressure may be variable so as to be able to adjust the bias level. It will be realised that the bias provided by the air pressure is analogous to a spring or other resilient bias but has the advantage that it is both adjustable and does not suffer from variable response (such as an elastic limit or non linear response) nor is there any limit to the length of slack that can be rewound as there would be with a spring bias: the spooler can,rotate repeatedly until all the slack is rewound.

When dealing with long line lengths, typically the line when originally wound onto the reel 8 will be given a slightly twisted wind to prevent problems with kinking on take off from the reel.

The branches 6 and 7 which may be used to provide the jets of air preferably do not lie at exactly 180 degrees to each other, in order to ensure that any given time when one jet is directed between adjacent vanes the other jet is impinging on a vane, thus preventing the vaned casing from adopting a balanced position. Alternatively the jets could be arranged at a more oblique angle across the vanes.

Air under pressure is particularly convenient fluid to use in this invention since it is readily available and will not affect the working environment after use, but it is possible to envisage the use of other fluids, such as nitrogen in a clean room, to create the force on the vanes which drives the spooler. The spooler will however have utility in other environments besides manufacturing, eg in optical fibre cable laying.^'

The vanes 3 which are shown in Figure 1 as curved could alternatively be flat. It has been found that the provision of about twenty vanes produces a sufficiently continuous, even, rotational force on the spooler.

In a modified embodiment of the spooler the vanes may be provided on the outside of the cylindrical casing with jets of air being appropriately supplied to cause the spooler to rotate. It will also be realised that the casing need not be cylindrical, but of course that is the most convenient shape.

A tension in the cable of less than 1 Newton force has provided sufficient for preventing slack in an optical fibre being used in robot-operating wiring system, and in practice it is preferred to use a tension of less than 0.5 Newtons force, though the force required varies according to the type of fibre that is being used, for example whether it is a primary coated fibre, a package with a foamed outer coating such as that utilised in fibre blowing or a sheathed fibre or fibre bundle.

The extension 18 can include a hollow tubed portion which acts as a conduit for the source of air passing to the jets. The air source would have a suitable entry point into the base portion 11.

The spooler can be detached from the extension 18 to allow a new reel with cable or other line or filament to be substituted.

Claims

1. A spooler system including a spooler comprising a rotary member having a plurality of vanes and means for directing at least one jet of fluid onto the vanes to rotate the rotary member, the rotary member being adapted to provide a winding bias to a line on a reel.

2. A spooler system according to claim 1 in which the fluid is supplied from at least two jets.

3. A spooler system according to claim 2 in which the jets are arranged so that at least one jet is directed onto a vane when at least one other jet is directed between vanes.

4. A spooler system according to any preceding claim in which the fluid comprises air.

5. A spooler system according to claim 1, 2 or 3 in which the fluid comprises nitrogen.

6. A spooler system according to any preceding claim in which the vanes are curved.

7. A spooler system according to any of claims 1 to 5 in which the vanes are flat.

8. A spooler system according to any preceding claim in which the vanes are attached internally to a casing that comprises the rotary member.

9. A spooler system according to any of claims 1 to 7 in which the vanes are attached externally to a casing that comprises the rotary member.

10. A spooler system according to any preceding claim in which the rotary member is to attached a reel support.

11. A spooler system according to any preceding claim in which the tension in the cable is less than 1 Newton force when in use.

12. A spooler system according to any preceding claim in which the tension in the cable is less than 0.5 Newtons force when in use.

13. A method of providing a winding bias, the method comprising directing at least one jet of fluid onto vanes associated with a rotary member.

14. ^■ A method according to claim 13 in which the fluid is supplied from at least two jets disposed such that at least one jet is directed onto a vane when at least one other jet is directed between vanes.