GB2168391A - Apparatus paying off strand - Google Patents

Abstract

Wire (3) is drawn through a guide (4) at a point along the axis of a non-rotating bobbin (1), the wire passing over a circumferential rim (2) (which may be one rim of the bobbin or a freely-rotating spinner disc). A retarder is provided in the form of a cylindrical array of bristles (6) which project from a base (7) and extend parallel to the bobbin axis to contact the rim. With the wire sliding around the rim, the wire contacts the successive bristles and deflects them radially outwards, so that the wire is appropriately retarded. The deflection of the bristles is however small so that they are less susceptible to fatigue. The base may be formed in two halves placeable onto a reel rim from diametrically opposite sides, and may be adjusted along the axis of the reel. The bristles may be of plastics, carbon fibre or spring steel material. <IMAGE>

Description

SPECIFICATION Wire or thread paying off apparatus The present invention relates to an apparatus for paying off wire, thread or other elongate flexible material, hereinafter referred to for convenience as wire which expression is intended to encompass any such elongate flexible material. The apparatus finds utilisation particularly, but not exclusively, in the wire and cable industry where the wire is stored and transported as a winding on a reel or bobbin.

In known paying off apparatus, the reel or bobbin is mounted non-rotatably in a fixed position, usually with the bobbin axis vertical. A spinner disc is mounted on the axis of the bobbin and beyond one end of the bobbin, preferably just above the bobbin when the latter is mounted vertically. In use, the wire to be paid off is pulled from the bobbin and runs over the edge of the spinner disc to be guided through a point disposed generally on the bobbin axis but spaced from the spinner disc.

During the paying off procedure, the wire slides around the circumference of the spinner disc which thereby rotates. In other known apparatus, the spinner disc is omitted and the wire runs instead around the circumference of the rim of the bobbin.

This is generally less satisfactory since there is more friction between the wire and the rim than there would be with a spinner disc and also because any imperfections in the rim may cause the wire to catch and possibly break.

In both the above known apparatus, a retarder is provided to act on the wire to impart thereto a constant back tension. A well known form of retarder comprises a disc of radiating bristles mounted above the spinner disc or above the rim of the bobbin and fixed against rotation. The wire runs against these bristles to deflect successive bristles and thereby be retarded. Such bristle disc retarders are known as cats whisker retarders.

Cats whisker retards are however subject to certain disadvantages. The bristles are susceptible to eventual fatigue from a number of causes. Their deflection is out of the plane of their disc and cir cumferentially since the wire has an upward or ax ial component of movement as well as its rotational movement as it is wound off the bobbin.

The wire may have an abrasive surface which would cause rapid wear of bristles. Furthermore, at high running speeds, the wire may be thrown clear of the bristles such that there is no longer a retard ing action and the tension in the paid off wire will vary.

It has been proposed to overcome this latter dis advantage by providing instead of the cats whisker retarder or additionally thereto a hoop surrounding the spinner disc and provided with inwardly di rected bristles. However, this is not always reliable at high speeds in giving a constant tension.

Another disadvantage of known types of paying off apparatus provided with a spinner disc is that the spinner rotates and has a certain inertia such that when it is desired to stop the paying off, the spinner continues to rotate dragging the wire with it and thereby kinking or even breaking the wire.

Certain processes, such as knitting wire for use as oil filters or pan scourers require repeated stopping of the machine and therefore the paying off apparatus. Also, they require the wire to be fed at a very high speed and under low tension. For these purposes, cats whisker retarders have been found to be ineffective. In general, the optimum ratio of bristle to wire diameter is in the region of 10:1. Where the wire to be paid off is of very small diameter, the bristle diameter cannot be reduced accordingly without impairing its rigidity and it becomes useless for retardation. If the ratio is exceeded in order to maintain rigidity, the wire becomes damaged when run at high speed through the excessively thick bristles.

It is an object of the present invention to provide a paying off apparatus with retarding means which are operative over a range of tensions and wire speeds and particularly, but not exclusively, for use with fine wire running off at high speeds. it is also an object of the invention to provide an apparatus which overcomes the disadvantages set out above.

According to a first aspect of the present invention there is provided an apparatus for paying off wire or thread or other elongate flexible material (herein after wire) comprising disc means over the circumference of which the wire passes, the disc means being part of or mounted to a fixedly mounted bobbin or reel wound with the wire to be paid off, and retarder means comprising a substantially cylindrical array of bristles mounted to a nonrotating base substantially concentric with the bobbin or reel, the bristles extending from the base in a direction generally parallel to the axis of the bobbin and adapted to contact or pass so adjacent to said disc means that, in use, wire being paid off contacts said bristles in the region of said disc means. The bristles are preferably of plastics material, although they may be of metal or carbon fibre or any similar substitute.

The base may advantageously be located around the part of the bobbin remote from the disc means.

Alternatively, the base may encircle the bobbin at any desired axial location whereby it may be used with different sized bobbins or the bristles may bear against the disc means with a predetermined but variable force whereby the tension of the wire paid off may be varied to any desired degree.

According to a second aspect of the present invention there is provided a substantially cylindrical array of bristles for use with a bobbin or reel from which wire is to be paid off, each bristle extending generally parallel to the axis of the bobbin.

An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an apparatus embodying the invention shown in use; and Figure 2 is a perspective view of the apparatus in disassembled condition.

Referring now to the drawings, there is shown a bobbin or reel 1 wound with wire, thread or other flexible elongate material to be paid off. The bobbin 1 is held on a stand and fixed against rotation.

The wire is paid off around the circumference of a spinner disc 2 mounted for free rotation immediately above the bobbin 1. The wire 3 then passes through a guide 4, over a pulley 5 and hence to the work station where it is required. The bobbin 1 and spinner disc 2 are shownn as being mounted vertically, although they could equally well be mounted horizontally or at any desired angle.

The bobbin 1 is surrounded by a cylindrical array of bristles 6, each bristle extending in a direction generally parallel to the axis of the bobbin. the bristles 6 are held at their lower end (as seen in the Figures) on a base 7 which surrounds the bobbin. As can be seen in Figure 2, the base comprises two halves so that its installation is convenient. The base 7 shown comprises a steel box section to which is attached a plastic angle into which the bristles are fastened. Alternatively, the steel box section may be replaced by a steel angle, which would be easier to fabricate to the shape desired. The bristles are each of such length that they extend above the spinner disc 2 sufficiently far for them not to be hooked under the spinner during operation of the apparatus.A prefered length of bristle is 150mm. The bristles either touch the spinner disc or pass very closely thereto such that as the wire 3 is withdrawn around the circumference of the spinner disc 2 it contacts each bristle in turn forcing it outwardly by a small distance sufficient to allow the wire to pass.

Since the bristles move only a small amount, fatigue of the bristles is markedly reduced when compared to the bristles of the cat whisker retarder. Furthermore, the bristles touching the spinner disc 2 cause braking and the spinner disc moves only very slowly if at all. Thus, there is less problem with the wire breakage at machine stops caused by the inertia of known spinner discs.

The base 7 of the retarder is shown as being around the lower part of the bobbin 1. However, means are provided whereby it can be raised upwardly or otherwise along the axis of the bobbin.

This enables a retarder with standard bristle length to be used with bobbins of varying axial lengths.

Also, it allows the tension of the wire being paid off to be varied. As the base 7 is moved nearer to the spinner disc, the bristles contact the spinner disc with more force and therefore the retarding effect is greater. Thus the wire is paid off at a higher tension.

The apparatus has been described as comprising a spinner disc 2. However, this may be omitted and the wire paid off around the circumference of an upper rim of the bobbin 1. This may be effective where the rim is free from such imperfections as may cause the wire to catch.

The bristles are generally constructed of plastics material although they could be carbon fibres or even of spring steel material. The number of bristles may be varied to vary the tension at which the wire is paid off or the material of each bristle may be changed for similar effect.

The apparatus embodying the invention is particularly suited for paying off fine wire at high speeds, although it may also be used for other type of wire at any suitable speed.

Claims (6)

1. An apparatus for paying off wire, thread or other elongate flexible material, said apparatus comprising a circumferential rim surface over which the wire passes as it is drawn from a fixedly mounted bobbin or reel wound with the wire to be paid off, said rim surface being part of or mounted to said bobbin or reel, and a retarder comprising a substantially cylindrical array of bristles mounted to a non-rotating base substantially concentric with the bobbin or reel, the bristles projecting from the base in a direction generally parallel to the axis of the bobbin or reel and arranged to contact or pass so close to said circumferential rim surface that, in use, the wire being drawn from said bobbin or reel contacts said bristles in the region of said rim surface to deflect the successive bristles radially outwards as the wire slides around said rim surface.

2. An apparatus as claimed in claim 1, in which said rim surface is provided on a spinner disc mounted for free rotation beyond one end of the bobbin or reel.

3. An apparatus as claimed in claim 1 or 2, in which said base is formed as two separable halves to facilitate installation with respect to the bobbin or reel from diametricaily opposite sides thereof.

4. An apparatus as claimed in any preceding claim, in which said base is positioned around a rim of the bobbin or reel at the opposite end of the bobbin from the end beyond which the wire is drawn.

5. An apparatus as claimed in any preceding claim, further comprising means for adjusting the position of said base along the axis of the bobbin or reel.

6. An apparatus for paying off wire or thread or other elongate flexible material, substantially as herein described with reference to the accompanying drawings.