CA2079660A1 - Manufacture of cables - Google Patents
Manufacture of cablesInfo
- Publication number
- CA2079660A1 CA2079660A1 CA 2079660 CA2079660A CA2079660A1 CA 2079660 A1 CA2079660 A1 CA 2079660A1 CA 2079660 CA2079660 CA 2079660 CA 2079660 A CA2079660 A CA 2079660A CA 2079660 A1 CA2079660 A1 CA 2079660A1
- Authority
- CA
- Canada
- Prior art keywords
- die
- tube
- fluid
- container
- extrusible
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 13
- 239000012530 fluid Substances 0.000 claims abstract description 16
- 239000004020 conductor Substances 0.000 claims abstract description 10
- 239000011810 insulating material Substances 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims abstract description 6
- 238000003825 pressing Methods 0.000 claims abstract description 5
- 238000000886 hydrostatic extrusion Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 230000000903 blocking effect Effects 0.000 claims 1
- 238000001125 extrusion Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C23/00—Extruding metal; Impact extrusion
- B21C23/007—Hydrostatic extrusion
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Extrusion Of Metal (AREA)
Abstract
ABSTRACT
MANUFACTURE OF CABLES
A cable is formed by extruding an extrusible sheath through a die by applying pressure to a non-compressible fluid surrounding the sheath, the sheath having held within it at least one extrusible conductor, spaced from the sheath by pressure-transmitting material, such as compacted powdered insulating material.
Figure 2
MANUFACTURE OF CABLES
A cable is formed by extruding an extrusible sheath through a die by applying pressure to a non-compressible fluid surrounding the sheath, the sheath having held within it at least one extrusible conductor, spaced from the sheath by pressure-transmitting material, such as compacted powdered insulating material.
Figure 2
Description
~ ~ 7.~3 ~
MANUFACTURE OF CABLES
This invention relates to a method of manufacturing cables and especially, though not exclusively, to a method of manufacturing mineral insulated cables, that is to say, cables of the type consisting of one or more electrical conductors enclosed within a tubular metal sheath and insulated from the sheath by compacted powdered insulating material. The invention also relates to apparatus for carrying out such manufacture.
It is known to use a hydrostatic extrusion process to form cable cores and wires. In such processes, the metal to be shaped into a core or wire is preshaped to fit a die formed at one end of a high-pressure container. The metal is surrounded by a pressure -transmitting liquid inside the container. By applying a force to a plunger to compress the liquid within the container, pressure from the liquid gradually forces the metal through the die to form a cable core or wire.
Hydrostatic extrusion processes have not hitherto been used to manufacture cables, although it has now been found that such a process provides an economical and attractive alternative to conventional cable manufacturing processes.
Accordingly it is an object of the present invention to provide a novel and advantageous ~ethod of manufacturing cables.
According to one aspect of the present invention, there is provided a method of manufacturing a cable by hydrostatic extrusion including the step of extruding an extrusible elongate member through a die by applying pressure to a non-compressible fluid at least partially surrounding said elongate member, said member comprising an extrusible tube and at least one extrusible conductor held within and spaced from said tube by pressure-transmitting material.
It may further include the step of forming a fluid-tight seal in said die formed in a container by introducing one end of said member into said die prior to introducing said fluid into said container.
Preferably said pressure-transmitting material is mineral insulating material.
According to a second aspect of the present invention, there is provided an apparatus for manufacturing cables by hydrostatic extrusion including a substantia11y fluid-tight container capable of receiving an elongate member to be extruded, said member including an extrusible tube and at least one extrusible conductor held within and spaced from said tube by pressure-transmitting material and said container having a die formed in an outer wall thereof, one end of said member bein~
introduced into said die, in use; said container being arranged to contain a non-compressible fluid, said fluid at least partially surrounding said member; and means for applying pressure to said fluid sufficient to cause the tube and conductor to be extruded through the die.
One embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-Figure 1 is a cross-section of the apparatus according to one embodiment of the invention prior to extrusion of the cable;
Figure 2 is a cross-section of the apparatus of Figure 1 ~ ~3 ~ 6 'J
during the extrus~on process, and Figure 3 is a cross-section of the apparatus, according to a further embodiment of the invention, prior to extrusion of the cable.
In Figure 1 the preform 1 to be formed into a cable is shown prior to extrusion. It comprises a copper tube 5, lm in length with a diameter of 165mm. The tube walls are 15mm thick. At one of end of the tube 5 is a base plate 3 formed integrally with the tube. The tube 5 contains a copper conductor 9 spaced from the tube walls by pressure-transmitting mineral insulating material 7, such as magnesium oxide.
The insulating mater;al is held in place by a disc 11.
For extrusion, the preform 1 is inserted into a die 13, 15 formed in the bottom wall 19 of a container 17. The die has a part-conical section 13 open to the inside of the container 17 and a cylindrical section 15, open to the outside of the container 17.
The maximum diameter of the part-conical section 13 is larger than the outer diameter of the tube 5 so that the tube 5 can be held in place by forcing it into the die prior to extrusion. The minimum diameter of the part-conical section 13 is less than the outer diameter of the tube 5 and equal to the diameter of the cylindrical section 15. Thus, on forcing tube 5 through the die, it emerges outside the container 17 as a cable. If the diameter of section 15, and hence the cable diameter, is 15mm, the length of cable produced is approximately 90m.
The container 17 has a cylindrical wall 21 sealed at the bottom end by wall 19 and at the top end by a plunger 23.
Referring to Figure 2, during extrusion, after the preform 1 is inserted into the part-conical section 13, thereby sealing the die, the container is filled with hydraulic fluid 25.
By forcing the plunger 23 downwards, (towards wall 19 in the direction of the large arrow 26), the hydraulic fluid 25 is compressed and exerts a pressure on the tube 5 and back plate 3 in the directions shown by the small arrows. The effect of the 2 a 7.r~
pressure is to force the preform 1 down through the die 13, 15 thereby compacting the insulating material 7 and reducing the diameters of the tube 5 and conductor 9.
Clearly the shape of the die need not be part-conical; the die could have a partly ogival cross-section, for example, as shown in Figure 3.
To prevent leakage of the hydraulic fluid 7, it will be appreciated that the external surface of one end of the preform 1 could have a shape which matches the shape of the inner end part of the internal surface 13' surface of the die 31. In Figure 3, the inner end of the die 31 has a part ogival cross-section which is matched by the shape of one end of the preform 1. In the embodiment shown in Figure 1, for example, the preform could have the same conical shape as the part-conical section 13.
MANUFACTURE OF CABLES
This invention relates to a method of manufacturing cables and especially, though not exclusively, to a method of manufacturing mineral insulated cables, that is to say, cables of the type consisting of one or more electrical conductors enclosed within a tubular metal sheath and insulated from the sheath by compacted powdered insulating material. The invention also relates to apparatus for carrying out such manufacture.
It is known to use a hydrostatic extrusion process to form cable cores and wires. In such processes, the metal to be shaped into a core or wire is preshaped to fit a die formed at one end of a high-pressure container. The metal is surrounded by a pressure -transmitting liquid inside the container. By applying a force to a plunger to compress the liquid within the container, pressure from the liquid gradually forces the metal through the die to form a cable core or wire.
Hydrostatic extrusion processes have not hitherto been used to manufacture cables, although it has now been found that such a process provides an economical and attractive alternative to conventional cable manufacturing processes.
Accordingly it is an object of the present invention to provide a novel and advantageous ~ethod of manufacturing cables.
According to one aspect of the present invention, there is provided a method of manufacturing a cable by hydrostatic extrusion including the step of extruding an extrusible elongate member through a die by applying pressure to a non-compressible fluid at least partially surrounding said elongate member, said member comprising an extrusible tube and at least one extrusible conductor held within and spaced from said tube by pressure-transmitting material.
It may further include the step of forming a fluid-tight seal in said die formed in a container by introducing one end of said member into said die prior to introducing said fluid into said container.
Preferably said pressure-transmitting material is mineral insulating material.
According to a second aspect of the present invention, there is provided an apparatus for manufacturing cables by hydrostatic extrusion including a substantia11y fluid-tight container capable of receiving an elongate member to be extruded, said member including an extrusible tube and at least one extrusible conductor held within and spaced from said tube by pressure-transmitting material and said container having a die formed in an outer wall thereof, one end of said member bein~
introduced into said die, in use; said container being arranged to contain a non-compressible fluid, said fluid at least partially surrounding said member; and means for applying pressure to said fluid sufficient to cause the tube and conductor to be extruded through the die.
One embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-Figure 1 is a cross-section of the apparatus according to one embodiment of the invention prior to extrusion of the cable;
Figure 2 is a cross-section of the apparatus of Figure 1 ~ ~3 ~ 6 'J
during the extrus~on process, and Figure 3 is a cross-section of the apparatus, according to a further embodiment of the invention, prior to extrusion of the cable.
In Figure 1 the preform 1 to be formed into a cable is shown prior to extrusion. It comprises a copper tube 5, lm in length with a diameter of 165mm. The tube walls are 15mm thick. At one of end of the tube 5 is a base plate 3 formed integrally with the tube. The tube 5 contains a copper conductor 9 spaced from the tube walls by pressure-transmitting mineral insulating material 7, such as magnesium oxide.
The insulating mater;al is held in place by a disc 11.
For extrusion, the preform 1 is inserted into a die 13, 15 formed in the bottom wall 19 of a container 17. The die has a part-conical section 13 open to the inside of the container 17 and a cylindrical section 15, open to the outside of the container 17.
The maximum diameter of the part-conical section 13 is larger than the outer diameter of the tube 5 so that the tube 5 can be held in place by forcing it into the die prior to extrusion. The minimum diameter of the part-conical section 13 is less than the outer diameter of the tube 5 and equal to the diameter of the cylindrical section 15. Thus, on forcing tube 5 through the die, it emerges outside the container 17 as a cable. If the diameter of section 15, and hence the cable diameter, is 15mm, the length of cable produced is approximately 90m.
The container 17 has a cylindrical wall 21 sealed at the bottom end by wall 19 and at the top end by a plunger 23.
Referring to Figure 2, during extrusion, after the preform 1 is inserted into the part-conical section 13, thereby sealing the die, the container is filled with hydraulic fluid 25.
By forcing the plunger 23 downwards, (towards wall 19 in the direction of the large arrow 26), the hydraulic fluid 25 is compressed and exerts a pressure on the tube 5 and back plate 3 in the directions shown by the small arrows. The effect of the 2 a 7.r~
pressure is to force the preform 1 down through the die 13, 15 thereby compacting the insulating material 7 and reducing the diameters of the tube 5 and conductor 9.
Clearly the shape of the die need not be part-conical; the die could have a partly ogival cross-section, for example, as shown in Figure 3.
To prevent leakage of the hydraulic fluid 7, it will be appreciated that the external surface of one end of the preform 1 could have a shape which matches the shape of the inner end part of the internal surface 13' surface of the die 31. In Figure 3, the inner end of the die 31 has a part ogival cross-section which is matched by the shape of one end of the preform 1. In the embodiment shown in Figure 1, for example, the preform could have the same conical shape as the part-conical section 13.
Claims (6)
1. A method of manufacturing a cable by hydrostatic extrusion including the step of extruding an extrusible elongate member through a die by applying pressure to a non-compressible fluid at least partially surrounding said member, said member comprising an extrusible tube and at least one extrusible conductor held within and spaced from said tube by pressure-transmitting material.
2. A method as claimed in Claim 1 further including the step of forming a fluid-tight seal in said die formed in a container by introducing one end of said member into said die prior to introducing said fluid into said container.
3. Apparatus for manufacturing a cable by hydrostatic extrusion including a substantially fluid-tight container capable of receiving an elongate member to be extruded, said member including an extrusible tube and at least one extrusible conductor held within and spaced from said tube by pressure-transmitting material and said container having die in an outer wall thereof and one end of said member being introduced into said die, in use; said container being arranged to contain a non-compressible fluid, said fluid at least partially surrounding said member; and means for applying pressure to said fluid sufficient to cause the tube and conductor to be extruded through the die.
4. Apparatus as claimed in Claim 3 wherein said means for pressurising said fluid, is a plunger which forms at least part of a wall of the container.
5. Apparatus as claimed in Claim 3 wherein said member further includes, at at least one end of said tube, blocking means to confine said insulating material within said tube.
6. Apparatus as claimed in any of Claims 3 to 5 wherein the internal surface of the inner end of the die is shaped to match the external surface of said one end of said member, so as to prevent egress of said fluid from said container in use thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB919121042A GB9121042D0 (en) | 1991-10-02 | 1991-10-02 | Manufacture of cables |
| GB9121042.7 | 1991-10-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2079660A1 true CA2079660A1 (en) | 1993-04-03 |
Family
ID=10702375
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2079660 Abandoned CA2079660A1 (en) | 1991-10-02 | 1992-10-01 | Manufacture of cables |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0535835A1 (en) |
| AU (1) | AU2538792A (en) |
| CA (1) | CA2079660A1 (en) |
| GB (2) | GB9121042D0 (en) |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1186419A (en) * | 1967-09-14 | 1970-04-02 | British Insulated Callenders | Improvements in or relating to the manufacture of Copper Clad Aluminium Rod |
| SE327180B (en) * | 1968-03-15 | 1970-08-17 | Asea Ab | |
| DE1957700C3 (en) * | 1969-11-17 | 1979-01-11 | Tuerk & Hillinger Gmbh & Co, 7200 Tuttlingen | Device for manufacturing and compressing an electric heater |
| GB1340862A (en) * | 1970-12-18 | 1973-12-19 | Atomic Energy Authority Uk | Extrusion processes |
| SE350711B (en) * | 1971-02-10 | 1972-11-06 | Asea Ab | |
| SE370027B (en) * | 1973-01-30 | 1974-09-30 | Asea Ab | |
| GB2205263B (en) * | 1987-06-03 | 1991-03-06 | Ass Elect Ind | Manufacture of mineral insulated cables |
| US4933141A (en) * | 1988-03-28 | 1990-06-12 | Inco Alloys International, Inc. | Method for making a clad metal product |
| WO1990014671A1 (en) * | 1989-05-17 | 1990-11-29 | Metal Manufactures Limited | Manufacture of mineral insulated metal sheathed cables |
-
1991
- 1991-10-02 GB GB919121042A patent/GB9121042D0/en active Pending
-
1992
- 1992-09-18 GB GB9219764A patent/GB2260095A/en not_active Withdrawn
- 1992-09-18 EP EP92308547A patent/EP0535835A1/en not_active Withdrawn
- 1992-09-25 AU AU25387/92A patent/AU2538792A/en not_active Abandoned
- 1992-10-01 CA CA 2079660 patent/CA2079660A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| GB9121042D0 (en) | 1991-11-13 |
| EP0535835A1 (en) | 1993-04-07 |
| AU2538792A (en) | 1993-04-08 |
| GB9219764D0 (en) | 1992-10-28 |
| GB2260095A (en) | 1993-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5922155A (en) | Method and device for manufacturing an insulative material cellular insulator around a conductor and coaxial cable provided with an insulator of this kind | |
| RU2178349C2 (en) | Method for joining or welding metallic objects by means of electromagnetic field | |
| CA2060691C (en) | Full closure h-shaped connector | |
| US5408743A (en) | Process for connecting an electric cable having a light metal core to a standardized end element | |
| US3922769A (en) | Method for making composite wire | |
| US20020094715A1 (en) | Cap for an electrical connector | |
| CA1063969A (en) | Formation and utilization of compound billet | |
| US5499449A (en) | Method of manufacturing battery terminals | |
| CA2358574A1 (en) | Compression connector | |
| US3739470A (en) | Connector | |
| US3557301A (en) | Sheathing of electrical cables | |
| US3539708A (en) | Electrical connector and apparatus and method for making same | |
| US3010184A (en) | Method of making an electrical connection | |
| CA2079660A1 (en) | Manufacture of cables | |
| CA2008682C (en) | Method of and apparatus for making mineral insulated cable | |
| US2755926A (en) | Method of extruding elongated members | |
| ATE116470T1 (en) | COAXIAL CABLE. | |
| US3608026A (en) | Method of manufacturing rods or tubes from powder | |
| ES2014855A6 (en) | Large gauge insulated conductor and coaxial cable process for their manufacture. | |
| US4912842A (en) | Method and device to shape a braided sheath in a cable consisting of an outer covering, a braided sheath and conductors | |
| CA2159868A1 (en) | Flexible jumper and method of making | |
| US3805574A (en) | Equipment for extrusion | |
| USRE25847E (en) | Method op making an electrical connection | |
| RU2050605C1 (en) | Process of manufacture of dense multiple-conductor composite billets | |
| US3789642A (en) | Method for hydrostatic extrusion of tubes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |