GB2197992A

GB2197992A - Sheathed cable reclamation

Info

Publication number: GB2197992A
Application number: GB8711941A
Authority: GB
Inventors: Raymond Philip Walker
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-11-21
Filing date: 1987-05-20
Publication date: 1988-06-02
Also published as: GB8627926D0; GB8711941D0

Abstract

A sheathed cable 100 is led to rollers 10, 12 having cutting blades 20, 22 in the grooves of the rollers, where the sheath is cut into two parts. The sheath may be PVC or copper from a mineral-insulated copper and the filler 108 is collected at 110 while the internal conductors are collected on a reel. A loop of wedge-shaped wire (120, Fig. 4) may be used to strip the filler from the conductors. The wire in the loop is moved periodically to present a fresh sharp edge to the filler. <IMAGE>

Description

Sheathed Cable Reclamation DESCRIPTION The invention relates to recovery of materials from scrap and has particular, but not necessarily exclusive, application to recovery of materials from metal cased electrical cable, such as the well-known "pyro", which has one or more copper conductors inside a copper earthing sheath with an electrically-insulating and heat-resistant infill, most often magnesia.

Basically, for "pyro", the problem is to efficiently reclaim the copper, as the infill is an inert material not readily itself removed, say by chemical means or heat. In particular, improvement is sought herein over methods of removal that involve beating the "pyro" mechanically to break it up and release the infill, perhaps after cutting it into small lengths.

Recovery of material from P.V.C. sheathed wires, especially valuable metal conductor wires, say of copper, is also a problem now that burning off the covering is an unacceptable source of pollution and manual stripping of the sheathing is time consuming and tedious where large scale recovery is envisaged.

The present invention aims to solve the above mentioned problems.

Accordingly, the present invention proposes longitudinal cutting of the outer sheath, so that the latter is then readily removed to reveal inner wire(s).

Where the outer sheathing is metal, this may be readily spread after cutting to enable release of its infill from both the sheath and such wire(s). Otherwise with P.V.C. sheathed cable the wire(s) are readily separated from the sheath after longitudinal cutting.

Suitable apparatus employs a rotary blade, preferably with its cutting edge exposed in a circumferential groove through which the scrap is passed/drawn such as by pulling or pushing. The rotary blade means may comprise a pair of rollers with registering bladed grooves which rollers can themselves serve to provide traction on the scrap and cut the sheath of same at diametrically opposite positions thereby splitting the sheath into two halves.

Such halves and internal wires are readily guided off via a suitable block or other guide means at the exit from the nip of the roller, and provision may readily be made to collect any infill material. A block bored to receive the wire from which the infill material is to be removed is one particularly convenient embodiment, the inlet end being tapered and generally blade like to aid removal of the infill material from the wire. Where several wires are present a respective bore is provided for each wire.

The end may also serve to separate and deflect the severed outer sheath halves or a separate abutment may be provided for this purpose.

An alternative stripping technique utilises blade means comprising a flexible wire of wedge cross-section which is formed into a loop about the wire which is passed therethrough to strip off the infill material.

A prototype has been built and tested and practical implementation of this invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a part-sectional view of apparatus on I-I of Figure 2; Figure 2 is a view of the apparatus of Figure 1 from one side; Figure 3 is a diagrammatic illustration of the steps of sheathed cable reclamation according to one embodiment; and Figure 4 is an end view of a loop of wire used for stripping material from conductors, and also showing a cross-sectional view of the wire.

In the drawings, upper and lower registering rollers 10 and 12 make a nip at 14 whereat registering circumferential grooves 16, 18 each have intruding blades 20, 22 that will grip and cut through the sheath of a "pyro" cable. The rollers 10, 12 are keyed on shafts 24, 26 respectively, journaled one above the other in and extending between side plates 28, 30. For that purpose, reduced shaft ends 32, 34 are shown in ball-bearings 36, 38 set in counter bores 40, 42 of the side plate 28 and covered by clamp plates 44, 46 bolted (48, 50) in threaded bores of the side plate 28; and flanged bushes 52, 54 are shown bolted in holes 56, 58 through the other side plate 30. It will be evident that other journaling could be employed, say of rolleror needle-type at both side plates.Fastening of the rollers 10, 12 to keying on the shafts 24, 26 is shown by way of clamp nuts 60, 62 acting on washers 64, 66, but any suitable securing system may be used.

Ends of the shafts 24, 26 protruding beyond the side plate 30 are shown fitted with similar meshing gear wheels 68, 70 also conveniently keyed in place and located by clamp nuts 72, 74 and associated washers.

The lower shaft 26 is shown with an in-board drive gear wheel 78 keyed thereto and located relative to the gear wheel 70 by a spacer 80.

The side plates 28, 30 are shown welded to abase plate 82 itself secured to a frame bracket or angle at 84, 86. However, such is no more than exemplary, as, indeed, are the relative locations of side plates, rollers and gear wheels, and a sandwich or embedded construction for the bladed rollers.

In operation, drive applied by a chain, toothed belt, or gear system to the wheel 78 will result in substantially equal speeds of rotation for the rollers 10 and 12 into the grooved nip 14 of which "pyro" cable can be offered and will be gripped between, drawn through, and cut by the blades 20, 22, thus producing, beyond the nip 14, readily accessible halves of the sheath and internal wires all readily guided away via a suitable grooved or passaged guide block or other guide system. The thus-stripped copper will readily release the infill for easy collection, thereby resulting in complee reclamation of all con,stituent materials.

Experiments are in hand as to possible advantage for edge-serrated or segmented blades over "straight" cutting edges, and it will be evident that more than one set of rollers and/or -multiple-grooved may be provided.

Figure 3 shows a sheathed cable 100 being fed between the nip rollers 10, 12 where the outer sheathing is cut, conveniently at diametrically opposite locations, with the two halves thereof being shown separated off at A, B for which purpose abutment members 102 are provided. This leaves the central conductor(s) with some or all filling adhered therearound as at 104. Only one conductor is shown in the illustration. This conductor wire is fed into a bore of a stripping block 106, the bore of which is dimensioned to receive closely the conductor and the end of the stripping block is tapered to an annular cutting edge which serves to strip off the infill 108 as the conductor is drawn through. The infill is collected by any convenient vehicle - such as tray 110.

The conductor wire 112 is shown being wound onto a reel 114. The conductor can be secured to the reel so that driving of the reel can be used to draw the sheathed cable through the splitting and stripping stages.

An alternative is to push the sheathing through the splitting and stripping stages, indeed the splitting apparatus can be designed to grip the sheathing so that rotation of the cutting nip rollers serves to move the sheathing therethrough and to push the conductor(s) through the stripping block.

Figure 4 illustrates one way of stripping the infill from the conductors which ensures that a sharp edge is always available. The tapered stripping component comprises a loop of wedge shaped wire 120 which is arranged round the conductor. By indexing the wire periodically a sharp cutting edge 122 can be made available for longer periods of time than would be possible with a simple annular cutting orifice. A block may be provided to support the loop of wire.

Figure 3 shows separate abutments 102 for peeling back the split sheathing. In fact the block 106 can be used for this purpose. The wheels 10, 12 are shown dotted merely to indicate their presence and are in fact at 90 degrees to the position illustrated.

The afore-described apparatus and method can be used to recover P.V.C. sheathed cables, single or multi-core with each core single or multistrand, as well as metal sheathed cable such as "Pyro".

Claims

1. A method of reclaiming sheathed cables comprising longitudinal cutting of an outer sheath, so that the latter is then readily removed to reveal inner wire or wires.

2. A method as claimed in claim 1 for sheathed cables having an infill between the outer sheath and inner wires further comprising releasing its infill from both the sheath and such wire or wires.

3. A method as claimed in claim 1 or 2 in which the outer sheath is cut using a rotary blade.

4. A method as claimed in claim 1, 2 or 3 in which the sheath is cut at diametrically opposite positions thereby splitting the sheath into two halves.

5. A method as claimed in one of claims 1 to 4 in which the cut sheath is guided off via a block or other guide means and the wire or wires are stripped of infill by passing through a bore in said block or other blade means.

6. A method as claimed in any one of claims 1 to 5 in which the sheath is passed between a pair of rollers having registering bladed grooves to split the sheath at diametrically opposite positions.

7. A method as claimed in claim 6 in which the traction to draw the scrap through the rollers is provided by the nip of the bladed rollers on the sheath.

8. A method as claimed in ' any one of claims 1 to 6 in which the sheathing and/or wires are gripped downstream of the cutting position and pulled to cause the scrap to be drawn through the cutting station and the infill stripping position.

9. A method as claimed in claim 7 or 8 in which the winding of the wire(s) onto a reel serves to provide traction for the scrap.

10. A method of reclaiming sheathed cables substantially as hereinbefore described with reference to the accompanying drawings.

11. Apparatus for use in reclaiming sheathed cables comprising a support for the cable and cutting means comprising a rotary blade for cutting the outer sheathing longitudinally so that the latter is then readily removed to reveal inner wire or wires and release any infill from both the sheath and such wire(s).

12. Apparatus as claimed in claim 11 in which the blade comprises a cutting edge exposed in a circumferential groove through which the scrap is drawn.

13. Apparatus as claimed in claim 12 in which two such bladed circumferential grooves are provided in the form of rollers with their grooves in registration for passage therethrough of the scrap to cut the sheath of same at diametrically opposite positions.

14. Apparatus as claimed in any one of claims 11, 12 or 13 further comprising a block for separating the sheath from the wire(s) and/or annular blade means through which a wire is passed for stripping of the infill therefrom.

15. Apparatus as claimed in claim 14 in which the annular blade means is part of the block.

16. Apparatus as claimed in claims 14 or 15 in which the annular blade means is formed by a bore in the block.

17. Apparatus as claimed in claim 14 or 15 in which the annular blade means is formed by a loop of wire.

18. Apparatus as claimed in claim 17 in which the wire has a wedge shaped cross-section.

19. Apparatus as claimed in any one of claims 11 to 18 further comprising traction means for drawing the scrap through the cutting means.

20. Apparatus as claimed in claim 13 or any of claims 14 to 19 when appendant to claim 13 in which the rollers are rotatably driven and the nip of the bladed grooves on the scrap provides the traction therefor.

21. Apparatus for use in reclaiming sheathed cables constructed and arranged substantially as illustrated and with reference to Figures 1 and 2 or 3 or 4.