GB2257064A - Mineral insulated cable manufacture - Google Patents
Mineral insulated cable manufacture Download PDFInfo
- Publication number
- GB2257064A GB2257064A GB9211945A GB9211945A GB2257064A GB 2257064 A GB2257064 A GB 2257064A GB 9211945 A GB9211945 A GB 9211945A GB 9211945 A GB9211945 A GB 9211945A GB 2257064 A GB2257064 A GB 2257064A
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- Prior art keywords
- rolls
- pair
- filled tube
- cross
- openings
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
- H01B13/004—Apparatus or processes specially adapted for manufacturing conductors or cables for manufacturing rigid-tube cables
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/38—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, pack rolling
- B21B2001/383—Cladded or coated products
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Metal Rolling (AREA)
Abstract
In a rolling mill 14 for use in the manufacture of mineral insulated electric cable, each roll of each pair 21, 21'... of rolls has in its circumferential surface at least two circumferentially continuous grooves 25, 25'... each of which co-operates with the corresponding groove of the other roll of the pair to define a circular opening. The openings defined by the co-operating grooves 25, 25'... of each pair 21, 21'... of rolls are of cross-sectional sizes differing from one another. Preferably, each pair 21, 21'... of rolls is so mounted on a rigid support structure that the pair of rolls is adjustable with respect to the support structure in a direction parallel to the axes of the rolls. The rolling mill is less expensive and more efficient than rolling mills hitherto proposed and used in the manufacture of mineral insulated electric cable. <IMAGE>
Description
MINERAL INSULATED CABLE MANUFACTURE
This invention relates to a method of, and apparatus for, manufacturing mineral insulated electric cables, that is to say cables of the kind comprising at least one elongate conductor insulated from a surrounding sheath of metal or metal alloy, and where there is more than one elongate conductor from the other conductor or conductors, by compacted mineral insulating powder, usually but no necessarily magnesium oxide.
In methods of manufacturing mineral insulated electric cables hitherto proposed and/or employed, mineral insulating powder and a conductor rod or conductor rods are simultaneously introduced into a preformed metal tube of a predetermined length, the powder is densely packed in the tube and around the conductor rod or rods to form what will hereinafter be referred to as "a filled tube", and the filled tube is then caused to pass through means which reduces the filled tube to the required cross-sectional shape and size. In some cases, the preformed metal tube of predetermined length is two or more preformed metal tubes welded end-to-end during the course of the process as described and claimed in our British Patent No.: 2093262B.
It is common practice to employ, as the means which reduces the filled tube to the required cross-sectional shape and size, at least one rolling mill comprising a plurality of pairs of rotatably driven rolls which are mutually spaced apart in the direction of travel of the filled tube. Each roll of each pair of rolls of the mill has in its circumferential surface a circumferentially continuous groove which co-operates with the groove of the other roll of the pair to define an opening through which the filled tube passes, the opening defined by the co-operating grooves of each pair of rolls, except the first pair of rolls, being of a cross-sectional size smaller than that of the opening defined by the co-operating grooves of the preceding pair or rolls so that the cross-sectional size of the filled tube is reduced in predetermined stages as the filled tube travels through the plurality of the rolls of the rolling mill. With a view to maintaining the cross-sectional shape of the filled tube as it passes through the pairs of rolls of the mill approximately circular, it is the custom to dispose adjacent pairs of rolls so that their axes are inclined substantially normal to one another and to provide downstream of the rolling mill or mills at least one pair of finishing rolls which finally forms the reduced filled tube into a cross-section of substantially circular shape.Usually, to enable a mineral insulated electric cable to be made of any one of a plurality of cross-sectional sizes lying between the upper and lower limits defined by the plurality of pairs of rolls of the rolling mill, at least some of the pairs of rolls at or near the downstream end of the rolling mill are so mounted in the mill that they can be moved so that they play no part in reducing the cross-sectional size of the filled tube. A rolling mill as so described will hereinafter be referred to as "of the kind described".
After the filled tube has been reduced by pairs of rolls of a rolling mill or mills of the kind described to a substantially circular cross-sectional shape of the required size, the reduced filled tube passes through in-line annealing apparatus, positioned downstream of the rolling mill or mills, and is coiled in a multiplicity of superimposed turns by means of equipment generally known and hereinafter referred to as a down coiler. A down coiler includes a circular block which is mounted with its axis vertical and which can be rotatably driven about its axis to impart a tensile force to a filled tube and so draw the filled tube through processing stations of a mineral insulated electric cable manufacturing line.Filled tube manufactured in and advancing from the cable manufacturing line passes several times around the block and, as the rotatably driven block continues to impart a tensile force to the filled tube and so draw it through the cable manufacturing line, coils of filled tube from the block drop successively into a pak positioned beneath the down coiler in a multiplicity of superimposed turns.
Where it is desired to provide for manufacture of mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another, it has been proposed to employ apparatus comprising a plurality of rolling mills of the kind described disposed in line, a plurality of in-line annealing apparatus, each downstream of a rolling mill or of at least two rolling mills, a plurality of down coilers, each down coiler being disposed downstream of an in-line annealing apparatus and, immediately upstream of each rolling mill, except at least the first rolling mill, means for accommodating a pak containing coils of filled tube coiled in a multiplicity of superimposed turns.Whilst the aforesaid apparatus enables a mineral insulated electric cable of any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of crosssectional sizes differing from one another to be manufactured, it has the serious disadvantages that it is extremely expensive in capital outlay in view of the number of rolling mills of the kind described and in-line apparatus required and is extremely inefficient when mineral insulated electric cable of a larger cross-sectional size is being manufactured and a rolling mill or rolling mills and in-line apparatus associated therewith are lying idle.
It is an object of the present invention to provide an improved method of, and improved'apparatus for, manufacturing mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another in which a predetermined length of filled tube is caused to pass through one or more than one rolling mill of the kind described, which improved method and improved apparatus are substantially less expensive and substantially more efficient than the methods and apparatus hitherto proposed and used for this purpose.
In the improved method according to the inventions, the rolling mill, or at least the last rolling mill, is so modified that each roll of each pair of longitudinally spaced pairs of rotatably driven rolls has in its circumferential surface at least two circumferentially continuous grooves each of which cooperates with a groove of the other roll of the pair to define an opening, the openings defined by the co-operating grooves of said pair of rolls being of cross-sectional sizes differing from one another, the openings of the co-operating grooves of said plurality of pairs of rolls of the mill constituting at least two series of openings in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by cooperating grooves of the preceding pair of rolls and the last opening of each of said series of openings, except the last of said series of openings, being of a crosssectional size greater than the first opening of the immediately succeeding series of openings; the filled tube is caused to pass through a first series of openings defined by co-operating grooves of the plurality of pairs of rolls of said modified mill so that the cross-sectional size of the filled tube is reduced in predetermined stages, the partially reduced filled tube is caused to pass through in-line annealing apparatus disposed downstream of said modified mill and is coiled in a pak in a multiplicity of superimposed turns by a down coiler; and the partially reduced filled tube from said pak is caused to pass through an immediately succeeding series of openings defined by cooperating grooves of the plurality of pairs of rolls of said modified mill so that the cross-sectional size of the partially reduced filled tube is further reduced in predetermined stages, the further reduced filled tube is caused to pass through said in-line annealing apparatus and is coiled in a pak in a multiplicity of superimposed turns by said down coiler.
Where each roll of each pair of rolls has in its circumferential surface three or more circumferentially continuous grooves each of which co-operates with a groove of the other roll of the pair to define an opening, e.g. four grooves, so that the openings of the co-operating grooves of said plurality of pairs of rolls constitute three or more series of openings, e.g. four series, in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by co-operating grooves of the preceding pair of rolls, the filled tube may be caused to make as many passes through the rolling mill and associated in-line annealing apparatus, using a different series of openings in each pass, as may be necessary to reduce the filled tube to the required cross-sectional size.
Preferably, in passing from an opening defined by co-operating grooves of one pair of rolls to an opening defined by co-operating grooves of an adjacent pair of rolls, the filled tube passes through a tubular guide which is fixed with respect to said pairs of rolls and into which a lubricant may be fed.
After each pass through a series of openings defined by co-operating grooves of the pairs of rolls of the modified mill and before its passage into said inline annealing apparatus, the partially reduced or reduced filled tube may be caused to pass through at least one pair of finishing rolls which forms the partially reduced or reduced filled tube into a crosssectional shape of substantially circular form.
Before each pass through a series of openings defined by co-operating grooves of the pairs of rolls of the modified mill, the filled tube or partially reduced filled tube may be caused to pass through means which straightens the filled tube or partially reduced filled tube and, after each such pass, and passage through the or each pair of finishing rolls when present, and before its passage into said in-line annealing apparatus, the partially reduced or reduced filled tube may pass through cleaning apparatus.
A plurality of filled tubes of the same cross-sectional shape and size may be reduced to the required cross-sectional size by forming a socket at the trailing end of one filled tube of predetermined length, inserting a body of metal or metal alloy in the bottom of the socket for detecting and identifying the position at which the reduced filled tube must be cut and, before the trailing end of said filled tube passes into the modified rolling mill or the first of the rolling mills, forming a plug at the leading end of another filled tube of predetermined length and fitting said plug into the socket at the trailing end of the first filled tube.
The invention further includes improved apparatus for use in the manufacture of mineral insulated electric cable having any one of a multiplicity of crosssectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another, which improved apparatus comprises a rolling mill comprising a plurality of longitudinally spaced pairs of rotatably driven rolls in which each roll of each pair of rolls has in its circumferential surface at least two circumferentially continuous grooves each of which cooperates with a groove of the other roll of the pair to define an opening, the openings defined by the cooperating grooves of said pair of rolls being of crosssectional sizes differing from one another, the openings of the co-operating grooves of said plurality of pairs of rolls constituting at least two series of openings in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by co-operating grooves of the preceding pair of rolls and the last opening of each of said series of openings, except the last of said series of openings, being of a cross-sectional size greater than the first opening of the immediately succeeding series of openings.
Where, as is preferred, each roll of each pair of rolls has in its circumferential surface four circumferentially continuous grooves each of which cooperates with a groove of the other roll of the pair to define an opening, the four openings defined by the cooperating grooves of said pair of rolls being of crosssectional sizes differing from one another; the openings of the co-operating grooves of said plurality of pairs of rolls constitute four series of openings in each of which series the opening defined by co-operating grooves of each pair or rolls, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by co-operating grooves of the preceding pair of rolls; and the last opening of the first series of openings has a cross-sectional size greater than that of the first opening of the second series of openings, the last opening of the second series of openings has a cross-sectional size greater than that of the first opening of the third series of openings and the last opening of the third series of openings has a cross-sectional size greater than that of the first opening of the fourth series of openings.
To provide for guiding and lubrication of a filled tube or partially filled tube through the rolling mill, preferably between adjacent pairs of rolls there is disposed a guide which is fixed with respect to said pairs of rolls and which has a plurality of rectilinear tubular passages in axial alignment with the openings defined by the co-operating grooves of said pairs of rolls. Preferably, also, means is provided for feeding a lubricant into each of said tubular passages.
With a view to facilitating feeding of a filled tube or a partially reduced filled tube through a series of openings in the rolling mill of the improved apparatus, preferably each pair of rolls, and each guide when disposed between adjacent pairs of rolls, is so mounted on a substantially rigid support structure that the pair of rolls, and guide, is or are adjustable with respect to the support structure in a direction substantially parallel to the axes of the rolls so that a selected opening defined by co-operating grooves of the rolls, and the associated rectilinear tubular passage in the guide, can be arranged to lie on the axis of an advancing filled tube or partially filled tube.
Such adjustment of each pair of rolls, and of each guide, may be effected by a pneumatically or hydraulically operated piston.
To enable a mineral insulated electric cable to be made of any one of a plurality of cross-sectional sizes lying between the upper and lower limits defined by the series of openings of the plurality of pairs of rolls of the modified rolling mill, preferably each of at least some of the plurality of pairs of rolls also has an opening which is defined by co-operating grooves of the rolls and which is of such a cross-sectional size that a partially reduced filled tube will pass freely therethrough without its cross-sectional size being further reduced by the pair of rolls.
The improved apparatus of the invention preferably also includes, downstream of the rolling mill, at least one pair of finishing rolls, preferably three pairs of finishing rolls, which will form a reduced filled tube into a cross-sectional shape of substantially circular form, each roll of the or each pair of finishing rolls having in its circumferential surface at least two circumferentially continuous grooves each of which cooperates with a groove of the other finishing roll of the pair to define an opening of substantially circular cross-section, the openings defined by the co-operating grooves of said pair of finishing rolls being of crosssectional sizes differing from one another.Preferably, the or each pair of finishing rolls is so mounted on a substantially rigid support structure that said pair of finishing rolls is adjustable with respect to said support structure in a direction substantially parallel to the axes of the finishing rolls.
The improved apparatus further also includes, downstream of the rolling mill, and finishing rolls when present, in-line annealing apparatus that can be readily modified for annealing partially reduced or reduced filled tube of any particular cross-sectional size and, upstream of said annealing apparatus, means for cleaning an advancing filled tube or partially reduced filled tube. Preferably, a down-coiler is disposed downstream of said in-line annealing apparatus and, preferably, also, means for straightening a filled tube or partially reduced filled tube is disposed upstream of the rolling mill.
The improved apparatus may be used in conjunction with and downstream of conventional apparatus for manufacturing mineral insulated cable, which conventional apparatus comprises a rolling mill of the kind described in which each roll of each pair has in its circumferential surface a single circumferentially continuous groove which co-operates with the groove of the other roll of the pair to define an opening and, downstream of the rolling mill of the kind described and upstream of the modified rolling mill of the improved apparatus, in-line annealing apparatus.
It will be appreciated that the improved method of, and apparatus for use in, manufacturing mineral insulated electric cable has the important advantages that mineral insulated cable having any one of a multiplicity of cross-sectional sizes lying within a predetermined wide range of cross-sectional sizes can be manufactured using a single modified rolling mill, or only two modified rolling mills, and that during manufacture of any one of a majority of said multiplicity of cross-sectional sizes, no part of the apparatus is lying idle.
The invention is further illustrated by a description, by way of example, of preferred apparatus for use in the manufacture of mineral insulated electric cable with reference to the accompanying drawings, in which:- Figure 1 is a diagrammatic representation of the preferred apparatus;
Figure 2 is a fragmental diagrammatic side view of two pairs of rolls of the modified rolling mill of the preferred apparatus;
Figure 3 is a view taken in the direction of Arrow
A in Figure 2, and
Figure 4 is a sectional view taken on the line IV
IV in Figure 3.
Referring to the drawings, the preferred apparatus comprises conventional apparatus 1 and, downstream of the conventional apparatus, improved apparatus of the present invention.
The conventional apparatus 1 comprises a rolling mill 2 comprising a plurality of pairs of rotatably driven rolls which are mutually spaced apart in the direction of travel of a filled tube, cleaning apparatus 3 for cleaning a partially reduced filled tube emerging from the rolling mill and, downstream of the cleaning apparatus, in-line annealing apparatus for annealing the partially reduced filled tube. Each roll of each pair of rolls of the rolling mill 2 has in its circumferential surface a single circumferentially continuous groove which co-operates with the groove of the other roll of the pair to define an opening through which a filled tube F can pass.The opening defined by the co-operating grooves of each pair of rolls of the rolling mill 2, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by the co-operating grooves of the preceding pair of rolls so that the cross-sectional size of the filled tube F is reduced in predetermined stages as the filled tube travels through the plurality of the rolls of the rolling mill. As is the custom, adjacent pairs of rolls of the rolling mill 2 are so disposed that their axes are inclined normal to one another.
The improved apparatus 11 disposed downstream of the conventional apparatus 1 comprises straightening apparatus 12 for straightening partially reduced filled tube emerging from the in-line annealing apparatus 4, a modified rolling mill 14 comprising a plurality of pairs of rotatably driven rolls which are mutually spaced apart in the direction of travel of a partially reduced filled tube, cleaning apparatus 15, in-line annealing apparatus 16 and a down-coiler 17. Each roll of each pair of longitudinally spaced pairs of rotatably driven rolls of the modified rolling mill 14, of which first and second pairs 21 and 21' are shown in Figures 2 and 3, has in its circumferential surface four circumferentially continuous grooves 25,25'.... each of which co-operates with a corresponding groove of the other roll of the pair to define an opening, the openings defined by the co-operating grooves of said pair of rolls being of cross-sectional sizes differing from one another. The openings of the co-operating grooves 25,25'.... of the plurality of pairs 21,21'....
of rolls of the modified rolling mill 14 constitute four series of openings in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair 21 of rolls, is of a crosssectional size smaller than that of the opening defined by the co-operating grooves of the preceding pair of rolls.The last opening of the first series of openings defined by co-operating grooves 25,25'.... of each pair 21,21'.... of rolls has a cross-sectional size greater than that of the first opening in the first pair 21 of rolls of the second series of openings, the last opening of the second series of openings has a cross-sectional size greater than that of the first opening in the first pair of rolls of the third series of openings and the last opening of the third series of openings has a cross-sectional size greater than that of the first opening in the first pair of rolls of the fourth series of openings.
To provide for guiding and lubrication of a partially reduced filled tube passing through the modified rolling mill 14, upstream of the first pair 21 of rolls and between adjacent pairs 21,21'.... of rolls there is disposed a guide 22,22'.... which is fixed with respect to the pairs of rolls and which has four rectilinier tubular passages 24,24'.... in axial alignment with the openings defined by the co-operating grooves 25,25'.... of the pairs of rolls. A passage 26,26'.... entering into each tubular passage 24,24'....
enables a lubricant to be fed into the tubular passage.
With a view to facilitating feeding of a partially reduced filled tube through a selected series of openings in the modified rolling mill 14, each pair 21,21'.... of rolls, and each guide 22,22'...., is so mounted on a rigid support structure (not shown) that the pair of rolls, and guide, are adjustable with respect to the support structure in a direction parallel to the axes of the rolls so that a selected opening defined by co-operating grooves 25,25'.... of each pair of rolls, and the associated rectilinear tubular passage 24,24'.... in each guide, can be arranged to lie on the axis of an advancing partially reduced filled tube.The modified rolling mill 14 also includes, downstream of the last pair of rolls, a pair of finishing rolls for forming a partially reduced filled tube into a crosssectional shape of circular form, each roll of the pair of finishing rolls having in its circumferential surface four circumferentially continuous grooves each of which co-operates with a groove of the other finishing roll of the pair to define an opening of circular cross-section, the openings defined by the co-operating grooves of the pair of finishing rolls being of cross-sectional sizes differing from one another. The pair of finishing rolls is so disposed that the axes of the rolls are inclined normal to the axes of the rolls of the pairs 21,21'....
of rolls of the modified rolling mill 14.
On emerging from the in-line annealing apparatus 4 of the conventional apparatus 1, the partially reduced filled tube F passes through the straightening apparatus 12 into the first series of openings defined by cooperating grooves 25,25'.... of the plurality of pairs 21,21'.... of rolls of the modified rolling mill 14 so that the cross-sectional size of the partially filled tube is further reduced in predetermined stages.
Downstream of the pair of finishing rolls of the modified rolling mill 14, the partially reduced filled tube F passes through the cleaning apparatus 15 and inline annealing apparatus 16 to the down-coiler 17 where the partially reduced filled tube is coiled in a pak in a multiplicity of superimposed turns. The pak is then moved to a position P upstream of the straightening apparatus 12 and partially reduced filled tube F from the pak is caused to pass from the pak into the straightening apparatus and from the straightening apparatus into the second series of openings defined by co-operating grooves 25,25'.... of the pairs 21,21'....
of rolls of the modified rolling mill 14 so that the cross-sectional size of the partially reduced filled tube is still further reduced in predetermined stages.
After emerging from the pair of finishing rolls of the modified rolling mill 14, the further reduced filled tube F passes through the cleaning apparatus 15 and inline annealing apparatus 16 to the downcoiler 17 where it is again coiled in a pak in a multiplicity of superimposed turns. The further reduced filled tube F in the pak may be further reduced in cross-section, if desired, by repeating the passage of the partially reduced filled tube from position P through the improved apparatus 11 using the third, or third and fourth, series of openings defined by co-operating grooves 25,25'.... of the pairs 21,21'.... of rolls of the modified rolling mill 14 until a filled tube of the required cross-section is obtained.
Claims (23)
1. A method of manufacturing mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another in which a filled tube is caused to pass through one or more than one rolling mill of the kind described, wherein the rolling mill, or at least the last rolling mill, is so modified that each roll of each pair of longitudinally spaced pairs of rotatably driven rolls has in its circumferential surface at least two circumferentially continuous grooves each of which cooperates with a groove of the other roll of the pair to define an opening, the openings defined by the cooperating grooves of said pair of rolls being of crosssectional sizes differing from one another, the openings of the co-operating grooves of said plurality of pairs of rolls of the mill constituting at least two series of openings in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by co-operating grooves of the preceding pair of rolls and the last opening of each of said series of openings, except the last of said series of openings, being of a crosssectional size greater than the first opening of the immediately succeeding series of openings; the filled tube is caused to pass through a first series of openings defined by co-operating grooves of the plurality of pairs of rolls of said modified mill so that the cross-sectional size of the filled tube is reduced in predetermined stages, the partially reduced filled tube is caused to pass through in-line annealing apparatus disposed downstream of said modified mill and is coiled in a pak in a multiplicity of superimposed turns by a downcoiler; and the partially reduced filled tube from said pak is caused to pass through an immediately succeeding series of openings defined by cooperating grooves of the plurality of pairs of rolls of said modified mill so that the cross-sectional size of the partially reduced filled tube is further reduced in predetermined stages, the further reduced filled tube is caused to pass through said in-line annealing apparatus and is coiled in a pak in a multiplicity of superimposed turns by said downcoiler.
2. A method as claimed in Claim 1, wherein, in passing from an opening defined by co-operating grooves of one pair of rolls to an opening defined by cooperating grooves of an adjacent pair of rolls, the filled tube passes through a tubular guide which is fixed with respect to said pairs of rolls.
3. A method as claimed in Claim 2, wherein a lubricant is fed into each tubular guide.
4. A method as claimed in any one of the preceding
Claims, wherein, after each pass through a series of openings defined by co-operating grooves of the pairs of rolls of the modified mill and before its passage into said in-line annealing apparatus, the partially reduced or reduced filled tube is caused to pass through at least one pair of finishing rolls which forms the partially reduced or reduced filled tube into a crosssectional shape of substantially circular form.
5. A method as claimed in any one of the preceding
Claims, wherein, after each pass through a series of openings defined by co-operating grooves of the pairs of rolls of the modified mill, and passage through the or each pair of finishing rolls when present, and before its passage into said in-line annealing apparatus, the partially reduced or reduced filled tube passes through cleaning apparatus.
6. A method as claimed in any one of the preceding
Claims, wherein, before each pass through a series of openings defined by co-operating grooves of the pairs of rolls of the modified mill, the filled tube or partially filled tube is caused to pass through means which straightens the filled tube or partially reduced filled tube.
7. A method as claimed in any one of the preceding
Claims in which a plurality of filled tubes of the same cross-sectional shape and size are continuously reduced to the required cross-sectional size, wherein a socket is formed at the trailing end of one filled tube of predetermined length, a body of metal or metal alloy is inserted in the bottom of the socket for detecting and identifying the position at which the reduced filled tube must be cut and, before the trailing end of said filled tube passes into the modified rolling mill or the first of the rolling mills, a plug is formed at the leading end of another filled tube of predetermined length and said plug is fitted into the socket at the trailing end of the first filled tube.
8. Apparatus for use in the manufacture of mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another, which apparatus comprises a rolling mill comprising a plurality of longitudinally spaced pairs of rotatably driven rolls in which each roll of each pair of rolls has in its circumferential surface at least two circumferentially continuous grooves each of which co-operates with a groove of the other roll of the pair to define an opening, the openings defined by the co-operating grooves of said pair of rolls being of cross-sectional sizes differing from one another, the openings of the co-operating grooves of said plurality of pairs of rolls constituting at least two series of openings in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair of rolls, is of a crosssectional size smaller than that of the opening defined by co-operating grooves of the preceding pair of rolls and the last opening of each of said series of openings, except the last of said series of openings, being of a cross-sectional size greater than the first opening of the immediately succeeding series of openings.
9. Apparatus as claimed in Claim 8, wherein each roll of each pair of rolls has in its circumferential surface four circumferentially continuous grooves each of which co-operates with a groove of the other roll of the pair to define an opening, the four openings defined by the co-operating grooves of each pair of rolls being of cross-sectional sizes differing from one another; the openings of the co-operating grooves of said plurality of pairs of rolls constitute four series of openings in each of which series the opening defined by co-operating grooves of each pair of rolls, except the first pair of rolls, is of a cross-sectional size smaller than that of the opening defined by co-operating grooves of the preceding pair of rolls; and the last opening of the first series of openings has a cross-sectional size greater than that of the first opening of the second series of openings, the last opening of the second series of openings has a cross-sectional size greater than that of the first opening of the third series of openings and the last opening of the third series of openings has a cross-sectional size greater than that of the first opening of the fourth series of openings.
10. Apparatus as claimed in Claim 8 or 9, wherein between adjacent pairs of rolls there is disposed a guide which is fixed with respect to said pairs of rolls and which has a plurality of rectilinear tubular passages in axial alignment with the openings defined by the co-operating grooves of said pairs of rolls.
11. Apparatus as claimed in Claim 10, wherein means is provided for feeding a lubricant into each of the rectilinear tubular passages of each guide.
12. Apparatus as claimed in any one of Claims 8 to 11, wherein each pair of rolls is so mounted on a substantially rigid support structure that the pair of rolls is adjustable with respect to the support structure in a direction substantially parallel to the axes of the rolls so that a selected opening defined by co-operating grooves of the rolls can be arranged to lie on the axis of an advancing filled tube or partially filled tube.
13. Apparatus as claimed in Claim 10 or 11, wherein each pair of rolls and each guide disposed between adjacent pairs of rolls is so mounted on a substantially rigid support structure that each pair of rolls and each guide is adjustable with respect to its support structure in a direction substantially parallel to the axes of the rolls so that a selected opening defined by co-operating grooves of the rolls and the associated rectilinear tubular passage in the guide can be arranged to lie on the axis of an advancing filled tube or partially filled tube.
14. Apparatus as claimed in Claim 12 or 13, wherein the apparatus includes a pneumatically or hydraulically operated piston for effecting said adjustment of each pair of rolls, and of each guide when present.
15. Apparatus as claimed in any one of Claims 8 to 14, wherein each of at least some of the plurality of pairs of rolls also has an opening which is defined by cooperating grooves of the rolls and which is of such a cross-sectional size that a partially reduced filled tube will pass freely therethrough without its crosssectional size being further reduced by the pair of rolls.
16. Apparatus as claimed in any one of Claims 8 to 15, wherein the apparatus also includes, downstream of the rolling mill, at least one pair of finishing rolls which will form a reduced filled tube into a cross-sectional shape of substantially circular form, each roll of the or each pair of finishing rolls having in its circumferential surface at least two circumferentially continuous grooves each of which co-operates with a groove of the other finishing roll of the pair to define an opening of substantially circular cross-section, the openings defined by the co-operating grooves of said pair of finishing rolls being of cross-sectional sizes differing from one another.
17. Apparatus as claimed in Claim 16, wherein the or each pair of finishing rolls is so mounted on a substantially rigid support structure that said pair of finishing rolls is adjustable with respect to said support structure in a direction substantially parallel to the axes of the finishing rolls.
18. Apparatus as claimed in any one of Claims 8 to 17, wherein the apparatus further also includes, downstream of the rolling mill, and finishing rolls when present, in-line annealing apparatus that can be readily modified for annealing reduced or partially reduced filled tube of any particular cross-sectional size and, upstream of said annealing apparatus, means for cleaning an advancing filled tube or partially reduced filled tube.
19. Apparatus as claimed in Claim 18, wherein a downcoiler is disposed downstream of said in-line annealing apparatus.
20. Apparatus as claimed in any one of Claims 8 to 19, wherein means for straightening a filled tube or partially reduced filled tube is disposed upstream of the rolling mill.
21. Apparatus for use in the manufacture of mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another, which apparatus comprises a rolling mill of the kind described in which each roll of each pair has in its circumferential surface a single circumferentially continuous groove which co-operates with the groove of the other roll of the pair to define an opening, in-line annealing apparatus downstream of said rolling mill of the kind described, and, downstream of said in-line annealing apparatus, as claimed in any one of Claims 8 to 20.
22. Apparatus for use in the manufacture of mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
23. A method of manufacturing mineral insulated electric cable having any one of a multiplicity of cross-sectional sizes lying within a wide predetermined range of cross-sectional sizes differing from one another substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9211945A GB2257064A (en) | 1991-06-11 | 1992-06-05 | Mineral insulated cable manufacture |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB919112547A GB9112547D0 (en) | 1991-06-11 | 1991-06-11 | Mineral insulated cable manufacture |
| GB9211945A GB2257064A (en) | 1991-06-11 | 1992-06-05 | Mineral insulated cable manufacture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9211945D0 GB9211945D0 (en) | 1992-07-15 |
| GB2257064A true GB2257064A (en) | 1993-01-06 |
Family
ID=26299052
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9211945A Withdrawn GB2257064A (en) | 1991-06-11 | 1992-06-05 | Mineral insulated cable manufacture |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2257064A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2100159A (en) * | 1981-04-07 | 1982-12-22 | Cables De Lyon Geoffroy Delore | Apparatus for manufacturing cable having a metal sheath |
-
1992
- 1992-06-05 GB GB9211945A patent/GB2257064A/en not_active Withdrawn
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2100159A (en) * | 1981-04-07 | 1982-12-22 | Cables De Lyon Geoffroy Delore | Apparatus for manufacturing cable having a metal sheath |
Non-Patent Citations (1)
| Title |
|---|
| METALS HANDBOOK 8th Edition published by American Society of Metals. Pages 758 and 759 * |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9211945D0 (en) | 1992-07-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |