Improved electric cable

Abstract

 An improved electric cable is made according to the electric and size characteristics of Class 2 but which, owing to a greater number of small diameter wires, has a flexibility equal to or, at least for some sections, greater than that of cables of Class 5.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an improved construction for an electric cable conductor.

[0002] As is known, electric cables conventionally comprise one or more conductors or wires, coated by an insulating material.

[0003] The construction and characteristics of the mentioned conductors, according to reference rules, are divided into Classes, defining their electric, constructional and size characteristics.

[0004] The conductor family according to the present invention is referred to Class 2 of the IEC (International Electrotechnical Commission) 60228 rule.

[0005] The conductors in this Class are defined as "rigid" and they must comprise a small minimum number of component elementary wires (see the accompanying table).

[0006] The stiffness or rigidity characteristic of the conductor is a consequence of the greater diameter of the few elementary individual wires thereof, which, moreover, have a diameter which increases proportionately to the overall cross-section of the finished conductor.

[0007] Another required rule to be met is the maximum value of the electric resistance of the finished conductor.

[0008] Vice versa, the above mentioned standard or specification provides, in the Class 5, a conductor comprising a high number of small diameter elementary wires, thereby providing the conductor with flexibility properties, but with larger allowed electric resistance values.

[0009] It should be pointed out that a less electric resistance value would involve, the conductor cross-section being the same, a larger current capability.

[0010] In general, the flexibility of a conductor will depend, for each cross-section thereof, on the diameter of the elementary wires and their amounts, so as to meet the standardizing requirements and criteria related to their assembling for providing a reduced diameter of the finished product.

SUMMARY OF THE INVENTION

[0011] The aim and objects of the present invention is to provide a flexible conductor of Class 2, by suitably assembling a comparatively high number of small elementary wires, so as to provide said flexible conductor with the desired flexibility characteristics, similar to or better than those of Class 5, but with an electric resistance as that required by Class 2 (and accordingly a larger current flow capability).

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Further characteristics and advantages of the present invention will become more apparent hereinafter from the following drawings and enclosed tables.

[0013] It should be apparent that the invention can be made, for each cross-section, by exploiting the most suitable combination of the diameter of the selected elementary wire, in the range shown in the table, the elementary wire number to meet the required electric resistance characteristic, and the adopted assembling technique.

[0014] A further characteristic shown in the table is the small diameter of the finished conductor with respect to that of the equivalent conventional "rigid" conductor of Class 2 and, more specifically, with respect to that of the related conductor of Class 5.

Figure 1 shows a portion of the electric conductor according to the invention, the insulation material being partially removed;

Figure 2 is a view similar to figure 1;

Figure 3 is a view of the construction as cross-sectioned along the plane III-III of figure 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] With reference to the number references of the above mentioned figures, the insulated conductor construction according to the invention has been generally indicated by the reference number 1, and comprises the conductor 2 as insulated at 3.

[0016] The insulated electric conductor 1 according to the invention is constructed according to the electric characteristics and minimum wire number of Class 2 but, owing to the large number of said wires, which have a small diameter, has a flexibility equal to or better than that of the conductors of Class 5, for some cross-sections.

[0017] The table shows, for red copper conductors and pinned copper conductors, data related to parameters characterizing the construction of the present invention, for the disclosed cross-sections:

	CHARACTERISTICS
	1		2	3
Cross Section [mm2]	Maximum electric resistance [at 20°C]		Diameter of the used elementary wires [mm]	Maximum diameter of the conductor [mm]
	Red Copper [/km]	Tinned Copper [/km]
6	3.08	3.11	0.30 ÷ 0.90	3.2
10	1.83	1.84	0.30 ÷ 0.90	3.8
16	1.15	1.16	0.30 ÷ 0.90	4.9
25	0.727	0.734	0.30 ÷ 0.90	6.1
35	0.524	0.529	0.30 ÷ 0.90	7.2
50	0.387	0.391	0.30 ÷ 0.90	8.3
70	0.268	0.270	0.30 ÷ 0.90	10.0
95	0.193	0.195	0.30 ÷ 0.90	11.5
120	0.153	0.154	0.30 ÷ 0.90	13.0
150	0.124	0.126	0.30 ÷ 0.90	14.3
185	0.0991	0.100	0.30 ÷ 0.90	16.2
240	0.0754	0.0762	0.30 ÷ 0.90	18.7
300	0.0601	0.0607	0.30 ÷ 0.90	21.0

Claims

1. An improved conductor construction, of Class 2 according to the IEC 60228 standard, characterized in that said conductor construction comprises a plurality of small diameter elementary wires forming said conductor.

2. A conductor or cable construction, according to claim 1, characterized in that each said conductor wire has a diameter from 0.30 to 0.90 mm, depending on its cross-section.

3. A cable construction, according to claim 1 or 2, characterized in that said cable construction comprises electric characteristics of Class 2 and has a flexibility equal to or larger than the flexibility of the electric conductors of Class 5.

4. A cable construction, according to one or more of the preceding claims, characterized in that said conductors are made of tinned copper or red copper.

5. A cable construction, according to one or more of the preceding claims, characterized in that the red copper and tinned copper conductors have the following constructional parameters:

	CHARACTERISTICS
	1		2	3
Cross Section [mm2]	Maximum electric resistance [at 20°C]		Diameter of the used elementary wires [mm]	Maximum diameter of the conductor [mm]
	Red Copper [/km]	Tinned Copper [/km]
6	3.08	3.11	0.30 ÷ 0.90	3.2
10	1.83	1.84	0.30 ÷ 0.90	3.8
16	1.15	1.16	0.30 ÷ 0.90	4.9
25	0.727	0.734	0.30 ÷ 0.90	6.1
35	0.524	0.529	0.30 ÷ 0.90	7.2
50	0.387	0.391	0.30 ÷ 0.90	8.3
70	0.268	0.270	0.30 ÷ 0.90	10.0
95	0.193	0.195	0.30 ÷ 0.90	11.5
120	0.153	0.154	0.30 ÷ 0.90	13.0
150	0.124	0.126	0.30 ÷ 0.90	14.3
185	0.0991	0.100	0.30 ÷ 0.90	16.2
240	0.0754	0.0762	0.30 ÷ 0.90	18.7
300	0.0601	0.0607	0.30 ÷ 0.90	21.0

6. A cable construction, according to one or more of the preceding claims, characterized in that said cable construction comprises one or more of the disclosed and/or illustrated characteristics.

Drawing