US2004901A - Electrical conductor - Google Patents

Description

June 1935- D R. G. PALMER 2,004,901

ELECTRICAL CONDUCTOR Filed Dec. 18, 1925 E. 1 TE. E TE- 5 Tsfi T315 1 N VEN TOR.

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Patented June 11, 1935 UNITED STATES PATENT OFFICE- ELECTRICAL CONDUCTOR Dwight R. G. Palmer, South Orange, N. 1., as-

signor to General Cable Corporation, New York, N. Y., a corporation of New Jersey- Application December 18, 1925, Serial No. 76,182

7 Claims. (Cl. 173-267) My invention relates broadly to electrical conconductors housed within a flexible metallic ductors and more particularly to a construction armor. In two conductor cable one wire conof electrical conductor particularly adapted for veys the current to the service outlet while the use in the wiring of buildings and residences for other wire is grounded or in neutral and provides power and lighting current supply to outlets the return channel. Both conductors are gener- 5 throughout the building. ally rubber insulated and are mechanically pro- One of the objects of my invention is to protected by the use of cotton braids or with other vide an electrical assembly which may be maninsulating or metallic protection. I provide an ufact-ured more inexpensively than assemblies insulated metallic conductor and an uninsulated heretofore employed for performing the same conductor of non-corrosive metal which extends 10 service, where less material is required in the parallel to, adjacent to, or is spiralled around manufacture of the assembly and smaller overthe insulated conductor forming a member adall size of the assembly is secured than has hereiacent to the insulated condu t r 0r conductors tofore been possible in wiring constructed for. and the inner walls of the metallic armor or 5 a similar purpose. sheathing. By virtue of the relatively small nother Object of my invention is to provide diameter of the uninsulated conductor the outer a conductor in which a housingsheath is armetallic armor or sheathing is substantially ranged to enclose an insulated and uninsulated smaller in diameter than the diameter of armored electrical conductor where the uninsulated eleca le heretofore required in this w A u 90 trical conductor lies adjacent the interior walls Stantlal saving in the material in the manufacof the sheath, the insulated conductor being for ture' of the assembly is therefore Obtainedthe purpose of carrying current while the unin- Referring to the drawing in more detail, refersulated conductor serves for the grounded side ence character I designates a metallic cond tor; of the circuit, that is the neutral conductor, and 2 an insulat n v in 3 a raid o raids th r 95 for polarity identification. over impregnated or finished with a moisture re- By reason of the construction of the conducpellent. A flexible metallic armor 4 encases the tor which I provide, Iam enabled to save concovered conductor I and interposed between the siderable material in its manufacture and yet outer covering 3 and the inner wall of the sheathprovide a safe electrical conductor for performing I provide an auxiliary conductor 5 of noning all of the functions of more expensive conc os ve m ta-L AS represented in F g. 1, the 3 ductors heretofore available in the art. auxiliary conductor 5 extends parallel to the in- My invention will be more fully understood sulated conductor I, while in Fig. 2 the conductor from the following specification by reference to 5 is twisted around the insulated conductor and the accompanying drawing, wherein: utilizes the armor as a joint ground. In Fig. 3 5 Figure 1 is side elevation of an armored cable I have shown the covered conductor l encased in partially broken away to illustrate the principle a sheath 6 of fibrous material with the auxiliary of my invention; Fig. 2 is a modified view oi an conductor 5 extending parallel to the covered conarmored cable in which the neutral conductor ductor I and immediately beneath the sheath 8. serves both as a mechanical spacing member for In 4 a C du o C stru d in co dance the insulated conductor and as the grounding with the conductor of Fig. 3 has been illustrated, 40 side of a circuit; Figs. 3 and 4 show applications but the auxiliary conductor 5 is spiralled beneath of my invention to electrical conductors prothe fibrous protector 6. vided with insulated sheaths under which the In Fig. 5 I have shown the conductor of my polarity identification conductor is arranged; Fig. invention housed within a stiff metallic conduit 1 5 is a fragmentary view of the conductor of my with the auxiliary conductor 5 immediately ad- 45 invention housed within a metallic or other conjacent the outer surface of the covering 3 in a duit; Figs. 6, 7, 8, 9 and 10 are cross-sectional position to establish electrical connection with views taken on lines 66, 88, 9-9 and the interior walls of the conduit 1. Illl1l of Figs. 1, 2, 3, 4 and 5, respectively; Fig. In Flg. 11 I have shown by reference character 11 shows the comparative saving in material in 8 the usual armored cable conductor in which 50 the assembly of my invention over the assembly twin conductors 9, each separately insulated are heretofore available in the art. encased, the conduit having a diameter rep- In the standard wiring of buildings or resiresented at A. In my construction the diameter dences it is customary to employ flexible arm- B of the flexible conduit is substantially smaller ored cable constituted by two or more insulated than the corresponding diameter A. This con- 55 struction brings about a saving in the cost of manufacture of the cable, the assembly cost, and reduces the expense in material cost by saving the expense of insulation of neutral conductor 5 and reducing the necessary diameter of the flexible conduit 4.

I have found that electrical conductors manuiactured in accordance with my invention, de-

' scribed herein, is practical in manufacture and and a pair of flexible metallic members helically woundaround said insulating covering, one of said pair of flexible members having a substantially circular cross-section and serving as a bare neutral conductor, and the other of said pair of flexible members being in the form of a band wound in overlapping and interlocking relation over said aforementioned flexible member of said pair for providing a flexible casing around Said insulated member and the other helically wound member. c

2. An electrical cable comprising a flexible conductor, an insulating covering for said conduc tor, and a pair of flexible metallic members helically spirally wound around said insulating covering and having a winding pitch differing one from the other, one of said helical members being wrapped about said insulating covering and serving as a bare neutral conductor and the other of said helical members being constituted by a helically wound interlocking member in electrical and mechanical contact with said aforementioned helical member for encasing said insulating covering.

3. An electrical cable of the class described comprising, in combination, an insulated live wire conductor, a flexible, helical, metal armor closely surroundingthe insulated lives-wire conductor, and a bare neutral or return conductor adapted to be connected with the grounded side of the line, said bare neutral conductor being disposed helically between the armor and the insulated conductor and in electrical contact with the former.

4. An electrical cable of the class described comprising, in combination an insulated live-wire conductor, a flexible, helical, metal armor closely surrounding the insulated live-wire conductor, and a bare neutral or return conductor adapted to be connected with the grounded side of the line, said bare neutral conductor disposed helically between the armor and the insulated conductor and in electrical contact with the former, the helix 0f the bare neutral conductor being of longer convolutions than the helix of the armor, the cable thus constituted being small, equally flexible in all directions and of substantially uniform over-all dimensions.

5. An electrical cable of'the class described, comprising, in combination, an insulated livewire conductor, a flexible, helical, metal armor closely surrounding the insulated live-wire conductor, and a bare neutral or return conductor disposed helically between the armor and the insulated conductor and in electrical contact with the armor, said bare neutral conductor being arranged in much longer convolutions than the armor and being of small dimension radially of the cable; i

6. An electric cable comprising, in combina tion, an insulated live-wire conductor, this wire with its insulation being circular in cross-section, a bare neutral orreturn wire disposed helically in long convolutions about the insulated conductor, said bare conductor having a relatively small dimension radially of the conductor, anda flexible, helical, metal armor applied in shorter convolutions about both conductors, the whole being a small uniformly flexible cable of substantially uniform over-all dimensions, suitable for housewiring.

'7. An electrical cable comprising, in combination, a flexible conductor, an "insulating covering for said conductor, a bare neutral conductor adapted to beconnected with the'grounded side of acircuit wound helically around the insulated conductor, and a flexible, helically wound metallic armor of shorter lay than the bare neutral conductor surrounding the insulated and bare neutral conductors, the bare neutral con- DWIGHT G. PALMER.

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