US3033916A - Electrical conductor - Google Patents

Description

May 8, 1962 D. H. scoFlELD 3,033,916

ELECTRICAL CONDUCTOR Filed June 16, 1958 INVENTOR O/VAD COF/[Z BY m 7% ATTORNEYS United States Patent hice 3,033,916 ELECTRICAL CONDUCTOR n Donald H. Scofield, Redwood City, Calif., assigner to Insul-S-Corp., San Carlos, Calif., a corporation of California Filed lune 16, 1953, Ser. No. 742,075 1 Claim. (Cl. 174-117) This invention relates broadly to electrical distribution systems and, more particularly, to electrical conductors for use in such systems.

It has heretofore been proposed, and is now known, to provide rigid or semi-rigid wires, cables, bars and the like across or through an area within which electrical energy must be supplied to one or more devices such as appliances, tools, machines and .the like. Such a condoctor is supplied with electricity from a suitable source and is tapped at one or more points along its length to provide electrical energy to the devices referred to. :In my co-pending application Serial No. 803,878, til-ed April 3, 1959, entitled Electrical Distribution System, there is disclosed and claimed such -a system, and in the present application I disclose and claim a conductor of new and improved structure ffor use in such la system and by reason of which improved operation is achieved.

The invention is described in the following speciiication and illustrated in the accompanying drawing in which:

FIG. l is a perspective view of a preferred form of conductor provided by the invention;

FIG. 2 is an elevational view showing a tap-cti device applied to the conductor of lFIG. 1;

FIG'. 3 is a perspective view of la second embodiment of the invention, and

FIG. 4 is `a part elevational part sectional view showing a tap-o device applied to the conducto-r of FIG. 3.

Electrical distribution systems of the type to which this invention relates are well known and, in general, comprise an electrical conductor which is suitably supportedat one or more points along its length and is tapped to provide electrical energy to an electrically operated device,',`such as a portable tool, light-ing fixture or the like.

The invention provides an electrical conductor of new and improved construction by reason of which improved and simplified tap-oit means may be used -to transmit electricity from the conductor to a device to be operated. A preferred embodiment of the new and improved conductor is disclosed in FIGS. 1 and 2 and comprises an elongated cable-like element formed of electrically non-conductive material such as -a plastic, hard rubber or the like. This conductor is of uni-form cross section throughout its length and this cross section comprises |a central part 2 Idefined by substantially parallel upper and lower walls 4, 6. At each side of this central part there is a part of outwardly decreasing thickness defined, on one side of the central part, by the outwardly converging upper and lower walls 8, and on the other side by the outwardly converging upper and iower walls 12, 14. 'Ihe upper and lower walls on each side of the central part 2 stop short of juncture and are connected at their outer edges by the side walls 16, 1S each oi which is formed with a central inwardly extending groove which extends longitudinally of the conductor throughout its length.

lMeans are provided by the invention for imparting strength and rigidity to the elongated conductor and such means comprise an elongated, relatively stiff member 20 which is embedded in the enlarged central part 2 of the conductor and which extends from end to end thereof. In the `disclosed embodiments of the invention this 3,633,916 Patented May 8, i962 member is a twisted, multi-strand wire rope, which is disposed midway between the upper and lower walls 4, 6 |and centrally between ythe side walls 16, 18.

Means are also provided by the invention for providing electrical energy along the length of the conductor and such means comprise the elongated electrically conductive wires 3i), 32 which are respectively disposed withing the side parts of the conductor which are defined, respectively, by the walls 8, 10, 16 on one side and walls l2, 14, 18 on the other. Each of these wires, which may be of stranded construction, extends throughout the length of the rconductor in spaced and parallel relation -to the central supporting and stiiening cable 20 and on the opposite sides thereof.

ln accordance with an important feature of the invention each ci the conductive wires 30, 32 is positioned inward of, and closely adjacent, the bottom of the groove 20 which is formed in a side wall 16, 18. Thus, each wire is covered on its outer surface, i.e., the surface removed from the strengthening and stiiening member 20, by only a very thin .membrane 40 which may be easily punctured when it its ldesired to make contact with the conductors in order to supply electricity `from them to a device which is to be operated.

A tapoii device for connecting the two conductors 30, 32 to such a device to be operated is illustrated in FIG. 3, in which there is shown a power take-oil" device the construction of which yforms no par-t of the present invention but is disclosed and claimed in the co-pending application referred to above. ,It will be seen, from FIG. Zand from the co-pending application, that this take-oli device comprises two parts S0, 52 which are brought together in clamping relation to the conductor and that these parts include pointed contact members 54, 56 which, when the takeoff device is in clamping engagement with the conductor, are positioned and operable to pierce the two membranes 4t? and engage the conductive wires 30, 32. l'hese contact members 54, 56 are connected to leads which conduct electricity to the device which is to be operated. .The power take-off device also includes a pointed ground contact member 58 which is positioned and openable, when the power take-olf device is in clamping relation to the conductor, to pierce the non-conductive material forming the central part of the conductor and engage the strengthening and stiifening member 20 in order to provide va ground Contact. This penetration of the central part of the'conductor tothe member 2i) is preferably made through the wall 6.

The plastic or other non-conductive material from which the central and side parts of the conductor are made is a unitary, integral structure which may be manu factored by an extrusion process and, in effecting this, the material may be extruded directly about the strengthening and stiiiening member 20 and the conductive wires 30, 32

A second embodiment of the invention is disclosed in FIGS. 3 and 4 of the drawi gs and, like the embodiment disclosed in FIGS. y1 `and 2, comprises an elongated, cable-like body formed of electrically non-conductive material. This body `is of uniform cross-sectional shape throughout its length and at each point along its length its cross section comprises a central annular part 60 which extends throughout the length of the conductor and has a substantially circular opening therein. A pair of converging arms 62, 64 extend outwardly from one side of the central part 60 and a second part of converg ing arms 66, 63 extend outwardly from the opposite side of the central part. The arms of each pair converge outwardly from the upper and lower parts of the central part 60 Iand therefore each pair of arms defines an opening or passage 70, 72 which extends throughout the length of the conductor. The arms of each pair substantially engage' each other at or adjacent' their outer ends land the arms are formed of a material which permits them to have some ilexibility whereby .they may be spread slightly inorder to give access to the opening 70 or 72 between the arms. l

A stitiening and strengthening member 74, which may be a stranded wire rope, is disposed Within the opening in the centnal part 6tland extends throughout the length of the conductor. Electrically conductive wires 76, 78 are disposed within the openings 70, 72 which are deined by the larmsof each pair of arms, and these wires extend throughout' the length of the conductor.

In` FIG. 4 of the drawings there is illustrated a power take-off device in operative relation to the conductordisclosed in FIG. 4. This takeoff device includes, `among other parts, two pointed contact members'92, 94 which, when the take-oftdevice is in operative clamping relation to the'conductor, p-ass between the arms 62, 64 onV one side of the conductor and between the arms 66, 68 on the other side into electrical contact engagementwith the wires T6, 78. The take-oit device also includes a ground contact member 96 and when the tap-ott` device is in operative clamping relation to the conductor this ground contact member penetrates the wall of the central part 6G' of the conductor to engage the strengthening and stitfening member 74 and eect a ground connection.

It is believed that the use andV `operation of conductors according to the invention will be fully understood from the foregoing description. Conductors `as described and illustrated in this specioation, and according to the invention, may be easily and .cheaply manufactured by an extrusion process but will be strong `and sumciently rigid, because oi the incorporation therein of the central strengthening and stitening member, to support any de- -sired number of power take-ott members and their associated leads. These conductors, including as they do electrically conductive wires which are normally surrounded and protected by the structure of the conductor itself, permit easy and quick take-off of electricity by reason of the fact that the lpart of the conductor which surrounds and protects the wires may be easily 'and quickly pierced or penetrated to give access lto the wires. The conductor also is so constructed that ity may be easily and quicklyl hung'or'otherwise installed by known devices.

While I have described and illustrated certain embodiments of my invention it will be apparent to those skilled in the art that otherV embodiments, as Well as modifications of those disclosed, may be made and practised without departing in any way from the spirit and scope of the invention, for the limits of which reference must be made to the appended claims.

What 4is claimed is:

An electrical conductor structure constructed and intended to be suspended for engagement by contact mernbers, comprising an elongated, unitary cable-like body formed of electrically non-conductive material, said body at each cross `section throughout its length having an enlarged central part comprising substantially parallel upper and lower parts `and oppositely extending side parts, each of said side parts being defined by upper and lower walls which converge outwardly from the central part to 4define an elongated channel extending the length of the side edges of the body, an elongated cable-like supporting member of substantial strength and rigidity embedded within said central part and extending substantially throughout the :length ot the elongated body and positioned therein to be engaged by'a contact member piercing the nonconductive material of the cable-like body, and .an elongated electrical conductor wire embedded in each of said side parts on opposite sides of said cablelike -supponting member and extending substantially throughout the length of the elongated body and adapted to be engaged by electrical .contact members piercing the non-conductive material ofy the cable-like body, each conductor wire lying adjacent the bottom of the said elongated channel.

References Cited'in'the tile of this patent- UNITED STATES PATENTS D. 185,855 Scofield Aug. 11, 1959 2,261,986 Frank et al Nov. 1l, 1941 2,619,553 Kroeckel ..-1 Nov. 25, 1952 2,749,261 Hardison- June 5, 1956 2,856,592v Carlson Oct. 14, y1.958 2,950,338 Taylor Aug. 23, 1960 FOREIGN PATENTS i 834,353 France Aug. 1'6, 1938 424,995 Italy Sept. 5, 1947 747,691 GreatV Britain Apr. 11, 1956

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