Power cable with plastic insulation and an outer conducting layer

• US 4,008,367 A
• Filed: 06/23/1975
• Issued: 02/15/1977
• Est. Priority Date: 06/24/1974
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Sunderhauf, Heinz
• Primary Examiner(s): Grimley, Arthur T.
• Application Number:
  US05/589,006
• Time in Patent Office: 603 Days
• Field of Search: 174/102 R, 174/102 SC, 174/105 SC, 174/106 SC, 174/107, 174/120 R, 174/120 SC, 174/120 SR, 174/110 PM
• US Class Current: 174/107
• CPC Class Codes: H01B 13/24 by extrusion extrusion of cables with plastic material in general B29C48/15
• CPC Class Codes: H01B 7/0275 comprising one or more extruded layers of insulation
• CPC Class Codes: H01B 9/00 Power cables

Abstract

In a power cable including a central conductor, an extruded inner conductor surrounding the conductor, an inner layer of extruded insulation surrounding the inner conducting layer, an extruded outer conducting layer surrounding the extruded insulation, a metal shield surrounding the outer conducting layer and an outer insulating sheath surrounding the metal shield, an intermediate insulating layer having a mechanical peel strength lower than that of the outer conducting layer and of the inner insulating layer is interposed between the inner insulating layer and the outer conducting layer to permit the outer insulating layer, metal shield and outer conducting layer to be easily peeled away from the inner insulating layer without damage to the outer conducting layer and without leaving a conducting residue on the inner insulating layer.

Claims

1. In a power cable including a central conductor, an extruded inner conducting layer surrounding said conductor, an inner layer of extruded insulation surrounding said inner conducting layer, an extruded outer conducting layer surrounding said insulating layer, a metal shield surrounding said outer conducting layer, and an outer insulating layer surrounding said metal shield, an improved construction permitting said outer insulating layer, metal shield and outer conducting layer to be peeled away from said inner insulating layer without damage to said outer conducting layer, comprising an intermediate insulating layer having a mechanical peel strength lower than the mechanical peel strength of the outer conducting layer and of said inner insulating layer, said intermediate insulating layer interposed between said inner insulating layer and said extruded outer conducting layer.

2. A power cable according to claim 1 wherein the mechanical strength of said intermediate layer is less than 60% of the mechanical strength of the plastic insulation and outer conducting layer.

3. A power cable according to claim 1 wherein said intermediate layer consists of a plastic material with an olifin polymerisate base.

4. A power cable according to claim 3 wherein said olifin polymerisate base has mixed therewith at least one of the group of inert mineral fillers consisting of chalk, chalk flint, kaolin, and silicon dioxide.

5. A power cable according to claim 2 wherein said intermediate layer is one of the group consisting of an insulating varnish and an insulating adhesive.

6. A power cable according to claim 5 wherein the wall thickness of said intermediate layer is between 0.1 and 0.3 mm.

7. A power cable according to claim 1 wherein said intermediate layer consists of a plastic material with an olifin polymerisate base.

8. A power cable according to claim 1 wherein said olifin polymerisate base has mixed therewith at least one of the group of inert mineral fillers consisting of chalk, chalk flint, kaolin, and silicon dioxide.

9. A power cable according to claim 1 wherein said intermediate layer is one of the group consisting of an insulating varnish and an insulating adhesive.

10. A power cable according to claim 1 wherein the wall thickness of said intermediate layer is between 0.1 and 0.3 mm.