CA1099877A - Production of cables with undulated tension relief elements - Google Patents
Production of cables with undulated tension relief elementsInfo
- Publication number
- CA1099877A CA1099877A CA295,249A CA295249A CA1099877A CA 1099877 A CA1099877 A CA 1099877A CA 295249 A CA295249 A CA 295249A CA 1099877 A CA1099877 A CA 1099877A
- Authority
- CA
- Canada
- Prior art keywords
- tension relief
- cable
- relief elements
- velocity
- undulated
- 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.)
- Expired
Links
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
- H01B13/22—Sheathing; Armouring; Screening; Applying other protective layers
- H01B13/24—Sheathing; Armouring; Screening; Applying other protective layers by extrusion
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Manufacturing Of Electric Cables (AREA)
- Insulated Conductors (AREA)
- Ropes Or Cables (AREA)
Abstract
PRODUCTION OF CABLES WITH UNDULATED
TENSION RELIEF ELEMENTS
Abstract In the production of electric cable in an extruder head having undulated tension relief elements embedded in the jacket, the jacketing material and tension relief elements are introduced at a velocity greater than the cable core, with such velocity being subsequently decreased to provide a compressive force which forms the undulations.
TENSION RELIEF ELEMENTS
Abstract In the production of electric cable in an extruder head having undulated tension relief elements embedded in the jacket, the jacketing material and tension relief elements are introduced at a velocity greater than the cable core, with such velocity being subsequently decreased to provide a compressive force which forms the undulations.
Description
This invention reLates to electric cables, and more particularly to electric cables having undulated tension relief elements embedded in the cable jacket.
U. S. Patents Nos. 3, 879, 518 and 3, 983, 313 disclose electric cables having undulated tension relief elements embedded in the cable jacket. In accordance with such patents, the cable jacket is formed of polyethylene and the undulation of the tension relief elements results from the shrinkage of polyethylene during cooling thereof.
In some cases, it is highly desirable to provide cables with undulated tension relief elements in which the cable jacket is îormed from a material other than polyethylene. For example, polyeth~lene is flammable and in cases where non-flammability is desired the cable jacket should be formed from a non-flammable mate~ial, such as, polyvinyl chloride; however, polyvinyl chloride does not have the shrinkage properties of polyethylene. As a result, undulation of the tension relief element can not be effected by cooling of the cable jacket~
In accordance with the present invention there is provided a process for providing a jacketed cable core having undulated tension relief elements therein by introducing a cable core, a jQcketing material and tension relief elements into an extruder head to produce a tubular jacket for the core having the tension relief elements embedded in the jacketing material, with the radial undulations of the tension reli~f elements being provided by ., ~, .~................. .
.
~~
87~
introducing the tension relie~ elements and the jacketing material at a velocity greater than the velocity of the cable core and thereafter reducing the velocity of the jacketing material having the tension relief elements therein to produce the undulations in the tension relief elements.
In this manner, the cable jacket can be produced from materials other than polyethylene in that the shrinkage properties of the polyethylene are no longer required for providing undulations in the tension relief elements.
~ qore particular ly, the relative velocities between the cable core and the jacketing material are controlled in a manner to generate an axial compressive force in the cable jacket and tension relief elements to pro-vide the undulations. The greater the difference in the relative speeds, the greater the undulations and by proper coordination the desired undulation can be achieved~
Accordingly, the abrupt axial compression which occurs at the extruder head outlet or beyond the discharge therefrom produces the undulation, whereby undulation of the tension relief elements can be obtained independently of the properties; i.e,, shrinkage property, of the jacketing material.
Thus, in accordance with the present invention, there is a retarding effect on the jacketing material including the tension relief strands and such retarding effect is provided by the velocity difference between the jacketing material and cable core.
' '' ' ~ '' "" . ' '':
In the case of a highly compressible and viscous jacketing material such compressive force is exerted immediately beyond the mouthpiece of the extruder head and there is a swelling of the jacketing material; i. e., the outer diameter of the jacket is greater than the inner diameter of the mouthpiece.
It is also possible to obtain such a retarding effect with a material of low viscosity and compressibility within the mouthpiece of the extruder head by providing a mouthpiece having an increas-ing inner diameter in the direction of flow, whereby the velocity of the jacketing material decreases as it passes through each larger area. In such a case, the tension relief elements would be fed at a rate corresponding to the velocity of the jacketing material in the smaller diameter area of the mouthpiece in order to provide the desired undulation.
The invention will b~ fur~er described with respect to the accompanying drawings, wherein:
Figure 1 is a schematic axial longitudinal sectional view through the extruder head of a cable extruding machine with a cable being made therein; and Fi gure 2 is a schematic plan v ew of a cable segment with partly exposed tension relief elements.
It is to be understood that the general principles for forming the Jacketed cable in accordance with the present invention are -3~
~9877 in accordance with those set ~orth in the aforementioned United States Patents Nos. 3,879,518 and 3,983,313, with the present invention differing from such patents by the fact that the jacket may be produced from materials other than polyethylene and that the undulations are formed by control-ling the parameters within the extruder head, as described, instead of depending on the shrinkage characteristics of the jacketing material.
Referring to the drawings, a cable extruder head 10 is provided with an opening 11 for coupling the screw of the extruder (not shown). A premade cable core 13 made of insulated electric conductors moves in the direction of arrow 12 into head 10 wherein the outer jacket 14 is applied there-on, to provide finished cable 15, which is cooled off in the commonly known manner.
As particularly shown in Figure 2, the finished cable 15 has a cable core comprised of conductors 16, insulation 17; i.e., five sets of two twisted conductor pairs 19, and a core 21 made of plastic material. Around the conductor pairs 19 is a commonly used wrapping 22 made of plastic bands.
The outer jackek 14 is extruded over wrappings 22 which moves with the cable core 13 into the extruder head wherein an alternating amount of tension relief elements 23 are provided. These elements may be constructed from groups of yarns or twines having different thread dimensions whereby the number of groups on the one hand and the number of yarns or twines for each group on the other hand depend on the number of conductor pairs l9, the required minimum breaking stress of the cable and ~he thread size. Such numbers also depend on the distance of the groups from each other and the distance of the groups to the inner jacket circumference. These tolerances are disclosed in the aforementioned United States Patents. It is essential that the tension relief elements 23 do not run through jacket l~ absolutely parallel to the cable axis (core 21); i.e., the tension relief elements should be undulated, as shown in Figure 2.
This provides an intimate positive locking between the tension relief elements and the jacket material.
Cable core 13 moves through a nozzle 25 in extruder head lO and discharges into a hollow chamber 30 into which the front ends of channels 26 discharge, with channels 26 being concentri-cally arranged with respect to the fed cable core 13 and of which only two channels are shown in Figure l. The channels 26 are provided with tension relief elements 28 from a supply station, preferably in the form of suspended rollers 27 which carry the yarns or twines 28.
The front end of extruder head lO has an outer matrix or mouthpiece 29 through which the finished cable 15 is withdrawn.
The tension relief elements 28 are imbedded in the jacketing . ``'' ' ''. .' ', . : ~ ' .
material (thermoplastic or elastomeric) introduced through screw coupling 11, and the funnel-shaped hollow chamber 30 receives the jacketing material with the embedded tension relief elements 28.
The speed or velocity of the jacketing material is dependent upon the e~erted pressure and the inner diameter of the mouth-piece 29 and the speed or velocity of the cable core 13 is equal to the drawing-off speed of the finished cable 15. The relative speed or velocit~r between the cable core and jacketing material is controlled in a manner such that the jacketing material moves through the head 10 at a velocity greater than the cable core.
The tension relief elements 23 also ~nove at a velocity greater than the velocity of the cable core and such velocity generally corresponds to the flow speed of the jacketing material.
l~s a resultJ the length of the tension relief elements 23 is longer than the leng~h of cable core 13 or finished cable 15, with the additional length being taken up in the undulation of the tension relief elements 2 3 .
As a result, the dimensions of the undulations can be controlled by controlling the relative velocities of the jacketing material and tension relief elements with respect to the cable coreO Such velocities can be controlled by controlling and/or adjusting the velocity of the cable core (draw-off speed of finished cable), mouthpiece diameter, pressure on jacketing ~0~377 material, etc .
A convenient manner of determining that there is a differencein relative velocities is by measuring the outer diameter of the cable after its discharge from the mouthpiece with respect to the mouthpiece inner diameter. In accordance with the invention, the outer diameter of the cable should be greater than the inner diameter of the mouthpiece wil;h the difference in diameter increas-ing as the relative speed of the jacketing material and tension relief elements increases with respect to the cable core. It has been found that the degree of undulation increases as the velocity difference increases (and the diameter difference between the finished cable and mouthpiece inner diameter increases3 and such difference should be coordinated to provide the required undulation without the tension relief elements overtaking themselves and forming S-like loops. At the e~treme, this could result in retarding the feed movement of the tension relief elements which would result in too great a tension which would reduce cable flexibility. As should be apparent, proper undulation improves flexibility as a result of the bellows effect which permits bending.
``I As should be apparent from the above description, aæ a result of the velocity difference between the jacketing material and cable core, the slower mo-vin~ cable cor e has a retarding effect on the faster moving tension relief elements at the time of forming the jacket on the core, whereby the tension relief ., . ~ , ~ .
elements are undulated, The invention will be further described with respect to the following example; however, the scope of the invention is not to be limited thereby:
EXAMP:LE
. _ In the following tests, the dimensions of the extruder headJ
pressure and charging rate OI the jacketing material is maintained constant for the several tests with respect to each jacketing material.
The drawing-off speed of the cable is changed to thereby change the velocity difference between the jacketing mate:rial and cable core, As the velocity of the jacketing material increases with respect to the cable core, the diameter of the finished cable increases with respect to the mouthpiece inner diameter and the degree of undulation increases.
C~ ~3 CJ) C~l ~p C~ N 1-~ U~
ll ll P-O
d E Q ~
o~ P)' ~ 1~ N ~
1~ N t~ N N N N N N ~ E~ ~. P
~ t~
~ I~
N N ~ ~ 1~ 1~ N N N t~
o o o o o o ~a o o o ~0~' t~ ~ ~ ~ N ~ ~ 1~ ~3 a) N o 1~ 0 O ~ O N E~ o d~
~ tl O
_ ~ ~_ ~ ~ ~ ~ 1~ 1-- N ~ Q ~ ~i ~D o E} ~
~R~
'.' -03 C~ ~ 3 ,_ 5 r.. E~ E~ 3 C3~ ~
~ .
`' ~7 ~ , ,.
The present invention is particularly advantageous in that it is possible to provide a jacketed cable having undulated tension relief element s without limiting the choice of jacketing material to only those that have certain shrinkage characteristics. Thus, for example, if flammability is a concern; e. g., for cables used in mines, a jacket material of low flammability such as polyvinyl chloride can be used. Any one of a wide variety of cables can be produced in accordance with the invention and the desirable properties imparted by undulated tension relief elements, and in particular undulated glass fibers, are not limited to self supporting air cables. For e~ampls, such properties would also have applicability in cables which have to be drawn in lengths Into pipes or shafts or which have to be placed into the ground .
Numerous modifications and variations of the present invention are possible in light of the above teachings and, therefore9 within the scope of the appended claims the invention may be practiced otherwise than as particularly described.
.. ..... .
U. S. Patents Nos. 3, 879, 518 and 3, 983, 313 disclose electric cables having undulated tension relief elements embedded in the cable jacket. In accordance with such patents, the cable jacket is formed of polyethylene and the undulation of the tension relief elements results from the shrinkage of polyethylene during cooling thereof.
In some cases, it is highly desirable to provide cables with undulated tension relief elements in which the cable jacket is îormed from a material other than polyethylene. For example, polyeth~lene is flammable and in cases where non-flammability is desired the cable jacket should be formed from a non-flammable mate~ial, such as, polyvinyl chloride; however, polyvinyl chloride does not have the shrinkage properties of polyethylene. As a result, undulation of the tension relief element can not be effected by cooling of the cable jacket~
In accordance with the present invention there is provided a process for providing a jacketed cable core having undulated tension relief elements therein by introducing a cable core, a jQcketing material and tension relief elements into an extruder head to produce a tubular jacket for the core having the tension relief elements embedded in the jacketing material, with the radial undulations of the tension reli~f elements being provided by ., ~, .~................. .
.
~~
87~
introducing the tension relie~ elements and the jacketing material at a velocity greater than the velocity of the cable core and thereafter reducing the velocity of the jacketing material having the tension relief elements therein to produce the undulations in the tension relief elements.
In this manner, the cable jacket can be produced from materials other than polyethylene in that the shrinkage properties of the polyethylene are no longer required for providing undulations in the tension relief elements.
~ qore particular ly, the relative velocities between the cable core and the jacketing material are controlled in a manner to generate an axial compressive force in the cable jacket and tension relief elements to pro-vide the undulations. The greater the difference in the relative speeds, the greater the undulations and by proper coordination the desired undulation can be achieved~
Accordingly, the abrupt axial compression which occurs at the extruder head outlet or beyond the discharge therefrom produces the undulation, whereby undulation of the tension relief elements can be obtained independently of the properties; i.e,, shrinkage property, of the jacketing material.
Thus, in accordance with the present invention, there is a retarding effect on the jacketing material including the tension relief strands and such retarding effect is provided by the velocity difference between the jacketing material and cable core.
' '' ' ~ '' "" . ' '':
In the case of a highly compressible and viscous jacketing material such compressive force is exerted immediately beyond the mouthpiece of the extruder head and there is a swelling of the jacketing material; i. e., the outer diameter of the jacket is greater than the inner diameter of the mouthpiece.
It is also possible to obtain such a retarding effect with a material of low viscosity and compressibility within the mouthpiece of the extruder head by providing a mouthpiece having an increas-ing inner diameter in the direction of flow, whereby the velocity of the jacketing material decreases as it passes through each larger area. In such a case, the tension relief elements would be fed at a rate corresponding to the velocity of the jacketing material in the smaller diameter area of the mouthpiece in order to provide the desired undulation.
The invention will b~ fur~er described with respect to the accompanying drawings, wherein:
Figure 1 is a schematic axial longitudinal sectional view through the extruder head of a cable extruding machine with a cable being made therein; and Fi gure 2 is a schematic plan v ew of a cable segment with partly exposed tension relief elements.
It is to be understood that the general principles for forming the Jacketed cable in accordance with the present invention are -3~
~9877 in accordance with those set ~orth in the aforementioned United States Patents Nos. 3,879,518 and 3,983,313, with the present invention differing from such patents by the fact that the jacket may be produced from materials other than polyethylene and that the undulations are formed by control-ling the parameters within the extruder head, as described, instead of depending on the shrinkage characteristics of the jacketing material.
Referring to the drawings, a cable extruder head 10 is provided with an opening 11 for coupling the screw of the extruder (not shown). A premade cable core 13 made of insulated electric conductors moves in the direction of arrow 12 into head 10 wherein the outer jacket 14 is applied there-on, to provide finished cable 15, which is cooled off in the commonly known manner.
As particularly shown in Figure 2, the finished cable 15 has a cable core comprised of conductors 16, insulation 17; i.e., five sets of two twisted conductor pairs 19, and a core 21 made of plastic material. Around the conductor pairs 19 is a commonly used wrapping 22 made of plastic bands.
The outer jackek 14 is extruded over wrappings 22 which moves with the cable core 13 into the extruder head wherein an alternating amount of tension relief elements 23 are provided. These elements may be constructed from groups of yarns or twines having different thread dimensions whereby the number of groups on the one hand and the number of yarns or twines for each group on the other hand depend on the number of conductor pairs l9, the required minimum breaking stress of the cable and ~he thread size. Such numbers also depend on the distance of the groups from each other and the distance of the groups to the inner jacket circumference. These tolerances are disclosed in the aforementioned United States Patents. It is essential that the tension relief elements 23 do not run through jacket l~ absolutely parallel to the cable axis (core 21); i.e., the tension relief elements should be undulated, as shown in Figure 2.
This provides an intimate positive locking between the tension relief elements and the jacket material.
Cable core 13 moves through a nozzle 25 in extruder head lO and discharges into a hollow chamber 30 into which the front ends of channels 26 discharge, with channels 26 being concentri-cally arranged with respect to the fed cable core 13 and of which only two channels are shown in Figure l. The channels 26 are provided with tension relief elements 28 from a supply station, preferably in the form of suspended rollers 27 which carry the yarns or twines 28.
The front end of extruder head lO has an outer matrix or mouthpiece 29 through which the finished cable 15 is withdrawn.
The tension relief elements 28 are imbedded in the jacketing . ``'' ' ''. .' ', . : ~ ' .
material (thermoplastic or elastomeric) introduced through screw coupling 11, and the funnel-shaped hollow chamber 30 receives the jacketing material with the embedded tension relief elements 28.
The speed or velocity of the jacketing material is dependent upon the e~erted pressure and the inner diameter of the mouth-piece 29 and the speed or velocity of the cable core 13 is equal to the drawing-off speed of the finished cable 15. The relative speed or velocit~r between the cable core and jacketing material is controlled in a manner such that the jacketing material moves through the head 10 at a velocity greater than the cable core.
The tension relief elements 23 also ~nove at a velocity greater than the velocity of the cable core and such velocity generally corresponds to the flow speed of the jacketing material.
l~s a resultJ the length of the tension relief elements 23 is longer than the leng~h of cable core 13 or finished cable 15, with the additional length being taken up in the undulation of the tension relief elements 2 3 .
As a result, the dimensions of the undulations can be controlled by controlling the relative velocities of the jacketing material and tension relief elements with respect to the cable coreO Such velocities can be controlled by controlling and/or adjusting the velocity of the cable core (draw-off speed of finished cable), mouthpiece diameter, pressure on jacketing ~0~377 material, etc .
A convenient manner of determining that there is a differencein relative velocities is by measuring the outer diameter of the cable after its discharge from the mouthpiece with respect to the mouthpiece inner diameter. In accordance with the invention, the outer diameter of the cable should be greater than the inner diameter of the mouthpiece wil;h the difference in diameter increas-ing as the relative speed of the jacketing material and tension relief elements increases with respect to the cable core. It has been found that the degree of undulation increases as the velocity difference increases (and the diameter difference between the finished cable and mouthpiece inner diameter increases3 and such difference should be coordinated to provide the required undulation without the tension relief elements overtaking themselves and forming S-like loops. At the e~treme, this could result in retarding the feed movement of the tension relief elements which would result in too great a tension which would reduce cable flexibility. As should be apparent, proper undulation improves flexibility as a result of the bellows effect which permits bending.
``I As should be apparent from the above description, aæ a result of the velocity difference between the jacketing material and cable core, the slower mo-vin~ cable cor e has a retarding effect on the faster moving tension relief elements at the time of forming the jacket on the core, whereby the tension relief ., . ~ , ~ .
elements are undulated, The invention will be further described with respect to the following example; however, the scope of the invention is not to be limited thereby:
EXAMP:LE
. _ In the following tests, the dimensions of the extruder headJ
pressure and charging rate OI the jacketing material is maintained constant for the several tests with respect to each jacketing material.
The drawing-off speed of the cable is changed to thereby change the velocity difference between the jacketing mate:rial and cable core, As the velocity of the jacketing material increases with respect to the cable core, the diameter of the finished cable increases with respect to the mouthpiece inner diameter and the degree of undulation increases.
C~ ~3 CJ) C~l ~p C~ N 1-~ U~
ll ll P-O
d E Q ~
o~ P)' ~ 1~ N ~
1~ N t~ N N N N N N ~ E~ ~. P
~ t~
~ I~
N N ~ ~ 1~ 1~ N N N t~
o o o o o o ~a o o o ~0~' t~ ~ ~ ~ N ~ ~ 1~ ~3 a) N o 1~ 0 O ~ O N E~ o d~
~ tl O
_ ~ ~_ ~ ~ ~ ~ 1~ 1-- N ~ Q ~ ~i ~D o E} ~
~R~
'.' -03 C~ ~ 3 ,_ 5 r.. E~ E~ 3 C3~ ~
~ .
`' ~7 ~ , ,.
The present invention is particularly advantageous in that it is possible to provide a jacketed cable having undulated tension relief element s without limiting the choice of jacketing material to only those that have certain shrinkage characteristics. Thus, for example, if flammability is a concern; e. g., for cables used in mines, a jacket material of low flammability such as polyvinyl chloride can be used. Any one of a wide variety of cables can be produced in accordance with the invention and the desirable properties imparted by undulated tension relief elements, and in particular undulated glass fibers, are not limited to self supporting air cables. For e~ampls, such properties would also have applicability in cables which have to be drawn in lengths Into pipes or shafts or which have to be placed into the ground .
Numerous modifications and variations of the present invention are possible in light of the above teachings and, therefore9 within the scope of the appended claims the invention may be practiced otherwise than as particularly described.
.. ..... .
Claims (4)
1. In the production of electric cable in a cable extruder head wherein a cable core, a jacketing material and tension relief strands are fed into the extruder head to produce a tubular jacket for the core having the tension relief strands embedded in the jacket material, an improved method for providing undulations in said tension relief strands, comprising:
forming said undulations by introducing the tension relief strands and the jacketing material into the extruder head at a velocity greater than the velocity of the cable core and there-after reducing the velocity of the jacketing material having the tension relief strands therein to effect compression and produce undulations.
forming said undulations by introducing the tension relief strands and the jacketing material into the extruder head at a velocity greater than the velocity of the cable core and there-after reducing the velocity of the jacketing material having the tension relief strands therein to effect compression and produce undulations.
2. The method of Claim 1 wherein the jacketed cable is with-drawn from the extruder head and has a diameter greater than the diameter of the outlet of the head.
3. The method of Claim 2 wherein the tension relief strands are glass fibers.
4. The method of Claim 3 wherein the jacketing material is polyvinyl chloride.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2702182.5 | 1977-01-20 | ||
| DE2702182A DE2702182C3 (en) | 1977-01-20 | 1977-01-20 | Process for the production of electrical cables with strain relief |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1099877A true CA1099877A (en) | 1981-04-28 |
Family
ID=5999094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA295,249A Expired CA1099877A (en) | 1977-01-20 | 1978-01-19 | Production of cables with undulated tension relief elements |
Country Status (28)
| Country | Link |
|---|---|
| JP (1) | JPS5391391A (en) |
| AR (1) | AR220114A1 (en) |
| AT (1) | AT362835B (en) |
| AU (1) | AU516418B2 (en) |
| BE (1) | BE862661A (en) |
| BR (1) | BR7800325A (en) |
| CA (1) | CA1099877A (en) |
| CH (1) | CH617528A5 (en) |
| CS (1) | CS207585B2 (en) |
| DD (1) | DD134162A5 (en) |
| DE (1) | DE2702182C3 (en) |
| DK (1) | DK148856C (en) |
| FI (1) | FI64250C (en) |
| FR (1) | FR2378339A1 (en) |
| GB (1) | GB1565763A (en) |
| GR (1) | GR66069B (en) |
| IE (1) | IE46028B1 (en) |
| IT (1) | IT1092533B (en) |
| LU (1) | LU78888A1 (en) |
| MX (1) | MX143709A (en) |
| NL (1) | NL176028C (en) |
| NO (1) | NO146154C (en) |
| NZ (1) | NZ186191A (en) |
| PL (1) | PL110166B1 (en) |
| PT (1) | PT67477B (en) |
| SE (1) | SE7714507L (en) |
| YU (1) | YU8478A (en) |
| ZA (1) | ZA78211B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4826346A (en) * | 1985-04-11 | 1989-05-02 | Mitsubishi Jukogyo Kabushiki Kaisha | Camshaft preferably for an internal combustion engine |
| US5767441A (en) | 1996-01-04 | 1998-06-16 | General Cable Industries | Paired electrical cable having improved transmission properties and method for making same |
| CN112848193A (en) * | 2020-12-31 | 2021-05-28 | 万江(厦门)线缆有限公司 | Double-layer cable, manufacturing method thereof and used mold |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2126751A1 (en) * | 1971-05-28 | 1972-12-07 | Kabel Metallwerke Ghh | Coaxial high-frequency cable with cavity insulation |
| GB1413674A (en) * | 1972-09-05 | 1975-11-12 | Lynenwerk Kg | Electric cables |
| US3983313A (en) * | 1972-09-05 | 1976-09-28 | Lynenwerk Kg | Electric cables |
-
1977
- 1977-01-20 DE DE2702182A patent/DE2702182C3/en not_active Expired
- 1977-09-23 DK DK422877A patent/DK148856C/en not_active IP Right Cessation
- 1977-11-28 AT AT0850577A patent/AT362835B/en not_active IP Right Cessation
- 1977-12-20 SE SE7714507A patent/SE7714507L/en not_active Application Discontinuation
- 1977-12-22 NO NO774423A patent/NO146154C/en unknown
- 1977-12-23 FI FI773920A patent/FI64250C/en not_active IP Right Cessation
- 1977-12-28 AR AR270544A patent/AR220114A1/en active
- 1977-12-29 PT PT67477A patent/PT67477B/en unknown
- 1977-12-29 FR FR7739607A patent/FR2378339A1/en active Granted
-
1978
- 1978-01-05 BE BE184120A patent/BE862661A/en unknown
- 1978-01-09 NL NLAANVRAGE7800257,A patent/NL176028C/en not_active IP Right Cessation
- 1978-01-09 CH CH19678A patent/CH617528A5/en not_active IP Right Cessation
- 1978-01-11 NZ NZ186191A patent/NZ186191A/en unknown
- 1978-01-12 ZA ZA00780211A patent/ZA78211B/en unknown
- 1978-01-17 YU YU00084/78A patent/YU8478A/en unknown
- 1978-01-18 LU LU78888A patent/LU78888A1/en unknown
- 1978-01-18 IE IE108/78A patent/IE46028B1/en unknown
- 1978-01-19 DD DD78203300A patent/DD134162A5/en unknown
- 1978-01-19 JP JP377278A patent/JPS5391391A/en active Granted
- 1978-01-19 IT IT19445/78A patent/IT1092533B/en active
- 1978-01-19 CA CA295,249A patent/CA1099877A/en not_active Expired
- 1978-01-19 BR BR7800325A patent/BR7800325A/en unknown
- 1978-01-19 PL PL1978204089A patent/PL110166B1/en unknown
- 1978-01-19 MX MX172104A patent/MX143709A/en unknown
- 1978-01-20 CS CS78407A patent/CS207585B2/en unknown
- 1978-01-20 AU AU32571/78A patent/AU516418B2/en not_active Expired
- 1978-01-20 GR GR55213A patent/GR66069B/el unknown
- 1978-01-20 GB GB2443/78A patent/GB1565763A/en not_active Expired
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