US3708608A

US3708608A - Electric power cord and method of making

Info

Publication number: US3708608A
Application number: US00108092A
Authority: US
Inventors: D Wyman
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-01-20
Filing date: 1971-01-20
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02

Abstract

An electric power cord comprising conductors made up of elongated conductive filaments encased by an insulating jacket. The filaments of each conductor are arranged and the jacket constructed to allow easy penetration thereof by conductive prongs of an electrical load member (e.g. a light). In addition, two cords can be placed side by side and electrically spliced by conductive prongs penetrated through the jackets and conductors of the adjacent cords. In the method of manufacture, continuous conductive filaments are juxtaposed and arranged to form apertured conductors and encased (in sets of two or three) with an easily penetrable, insulating material.

Description

Jan. 2, 1973 [541 ELECTRIC POWER CORD AND METHOD OF MAKING Dennis- G. Wyman, 4 Crestline Court, Owings Mills, Md. 211 17 Filed: 7 Jan. 20, 1971 Appl. No.:' 108,092

Inventor:

us. 01. ..174 70 11, 29/624, 174/117 R, 174/117 F, 336/96, 317/101 CM 1111.01. ..H0lb 7/08 174/117 As, 8.5, 70 R; 339/96, 98,2 LR;

Piel ..317/10l CM r" I g 'Il/i l/ Field 0fSearch.l74/ll3, 117 R, 117 F, 117 FF,

FOREIGN'PATENTS OR APPLICATIONS 1,299,075 6/1962 France 312,039 12/1955 Switzerland ..174/113 Primary Etaminer-E. A. Goldberg Attorney-Joseph R. Slotnik [5 7 ABSTRACT An electric power cord comprising conductors made up of elongated conductive filaments encased by an insulating jacket. The filaments of each conductor are arranged and the jacket constructed to allow easy penetration thereof by conductive prongs of an electrical load member (e.g. a light). In addition, two cords can be placed side by .side and electrically spliced by conductive prongs penetrated through the jackets and conductors of the adjacent cords. 1n the method of manufacture, continuous conductive filaments are juxtaposed and arranged to form apeitured conductors and encased (in sets of two or three) with an easily penetrable, insulating material.

9 Claims, 6 Drawing Figures PATENTEDJAN 2191a ATTORNEY but? ELECTRIC POWER CORD AND METHOD OF MAKING SUMMARY OF THE INVENTION The present invention is directed to a novel electric power cord which allows connection of an electric load member thereto at virtually any point along its length. The cord is constructed to facilitate ready and easy connection and disconnection of electric load members thereto without requiring tools of any kind. The cord is constructed to regain basically its original nature upon disconnection of any or all of the electric load members thereby rendering it highly versatile and very safe in use. Also, two or more cords are readily electrically connected and disconnected using one or more splicing members. Again, the cords allow connection and disconnection without tools of any kind, and regain essentially their original nature upon disconnection.

In the method of making this cord, continuous conductive filaments are kinked, arranged in sets of two or three to form conductors made up of a plurality of kinked filaments juxtaposed to one another but with the kinks displaced or offset relative to one another. The conductors are then fed through an extruding or draw casting die where an insulating jacket of soft, easily penetrable material is applied thereto. This method facilitates use of high speed forming techniques and results in a reliable and low cost product.

Main objects of the present invention, therefore, are to provide a novel electric power cord which facilitates ready connection and disconnection of one or more electric load members thereto at an infinite variety of positions along its length, which facilitates ready splicing and disconnection of two or more cords, which requires no tools of any kind to effect connection and disconnection of these electric load members thereto or for splicing and disconnection of two or more cords, and which cord returns basically to its original state upon disconnection of an electric load member or upon disconnection of two or more cords.

Further important objects of the present invention are to provide a novel method whereby a power cord of the above character is formed, continuously and inexpensively and results in a reliable, safe, and versatile product.

' Additional important objects of the present invention will become more apparent from a consideration of the detailed description and claims to follow taken in conjunction with the drawings annexed hereto.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating an electric power cord embodying .the present invention and shown with an electric load member connected thereto and one disconnected therefrom;

FIG. 2 is an enlarged sectional view of FIG. 1 taken along the line 2-2 thereof;

FIG. 3 is a view illustrating schematically a sectional plan view, in two dimensions, of the cord of FIG. 1;

FIG. 4 is an enlarged view illustrating one of the conductors of FIG. 3 and showing a conductive prong penetrated therethrough;

FIG. 5 is a view similar to FIG. 2 and showing two cords of the invention spliced together; and

FIG. 6 is a schematic view illustrating the method of the present invention.

BROAD STATEMENT OF THE INVENTION of said cord, said filaments of each conductor being juxtaposed substantially each said filament being deformed laterally of said cord substantially throughout their length and relative to a large number of the other of said filaments, whereby to define a series of random apertures therealong, said insulating jacket being formed of a soft, pliable, and easily penetrable material.

In another aspect, the present invention comprises an elongated cord having a plurality of spaced, parallel conductors extending substantially throughout its length, means at one end of said cord for connection of said conductors to an electric source, said conductors including electrically conductive filaments defining an open lattice having randomly spaced, relatively small apertures substantially continuously along their'length, a sheath of easily penetrable, self-sealing insulating material encasing said conductors, said cord receiving one or more pronged electrical load members along its length by manually pressing said prongs through said sheath and into said apertures in said conductors, said filaments being disposed within said sheath for limited. movement relative to one another when engaged by said prongs whereby to permit said apertures to shift, said sheath material being constructed to snugly grip said prongs to support and retain said load members and electrically protect said prongs, said sheath material being further constructed to reclose the openings formed therein by said prongs upon removal of said load members from said cord.

In still another aspect, the present invention relates to an electric power cord comprising a plurality of conductors formed from elongated conductive filaments laterally deformed regularly along their length, said filaments of each said conductor being displaced longitudinally of others of said filaments, whereby to define random, irregular apertures transversely through said conductors substantially continuously throughout their length, said conductors being encased by a sheath of pliable, easily penetrable material having inherent cold flow chacterictics.

In still another aspect, the present invention relates to an infinite female connector comprising two or more elongated conductors encased and separated by a jacket of relatively soft, pliable insulating material, said conductors including juxtaposed electrically conductive filaments movable relative to one another and defining randomly spaced, relatively movable apertures disposed substantially continuously along their length, means for connecting two of said conductors to an electric source, said jacket having good cold flow chacteristics and being easily penetrable by conductive prongs of an electrically conductive member to allow said prongs to engage and move said filaments and penetrate respective ones of said conductors by way of aligned ones of said apertures, said jacket material reclosing and rescaling the openings formed in said jacket by said prongs upon removal of said prongs therefrom.

In yet another aspect, the present invention relates to the method of making an electric power cord comprising the steps of selecting a plurality of elongated, laterally deformed electrically conductive filaments, arranging the filaments in spaced sets with the filaments of each set juxtaposed and the lateral deformations of each said filament being displaced longitudinally of the lateral deformations of a large number of the other of said juxtaposed filaments to define spaced, random and irregular apertures along said set, and encasing said filaments sets with an easily penetrable insulating material.

In yet another aspect, the present invention relates to the method of making an electric power cord comprising the steps of laterally kinking a plurality of substantially continuous conductive filaments, displacing at least some of said filaments longitudinally relative to others and arranging said filaments in laterally spaced sets, whereby to form random, irregular apertures substantially continuously throughout their length, and continuously encasing said spaced sets of filaments with an easily penetrable, electrically insulating material. v

DETAILED DESCRIPTION Referring now more specifically to the drawings, an electric power cord embodying the present invention is illustrated generally at 11 in FIG. I and is seen to include an elongated, flexible cord body 13 having a male plug connector 15 at one end thereof. The connector 15 has a plurality of

plug blades

17, 19 for connection to a conventional female plug receptacle.

As shown in FIG. 2, the cord body 13 includes a plurality of

conductors

21, 23 encased and separated from one another by an insulating sheath or jacket 25. The

conductors

21, 23 are made up of a plurality of individual wires 27 interconnected with respective ones of the

plug blades

17, 19.

As in conventional electric power cords, the cord of the present invention is adapted to have an electrical load member connected thereto. In accordance with the invention and as a result thereof, the cord 1 1 forms an infinite female connector and facilitates ready connection of one or more electrical load members thereto at virtually any point along its length.

As shown in FIG. 2 and schematically in FIG. 3, the individual wires 27 making up the

conductors

21, 23 are arranged such that they define spaced apertures 29. In a preferred form, this is achieved by forming at least some of the wires 27 with

alternate kinks

31, 33 defining a zigzag configuration, and displacing some of the wires 27 longitudinally relative to others as seen schematically in'two dimensions in FIG. 3. By so doing, the juxtaposed wires 27 of each

conductor

21, 23 define a three dimensional latticework. In actuality, the apertures 29 are randomly spaced along each conductor and define irregular paths transversely through the

conductors

21,23.

The insulating jacket 25 is preferably made from a relatively soft, flexible and easily penetrable material having inherent cold flow chacteristics. A number of synthetic materials possessing the necessary characteristics are readily available, among which are the class of highly plasticized polyvinyl chloride (PVC) known as plastisol. This material is particularly advantageous in that it is readily extruded in place over and around the

conductors

21, 23 and presents an attractive appearance and highly functional jacket.

The cord 11 is adapted to have one or more electric load members electrically connected thereto at virtually any position along its length. Exemplary load members are illustrated as electric lights shown at 35 in FIGS. 2 and 2. These lights 35 include a base 37 having an incandescent bulb 39 fixed thereto and provided with

conductive prongs

41, 43 dependent therefrom. The

prongs

41, 43 are spaced, center to center, a distance which corresponds to the center to center space of the

conductors

21, 23.

The lights 35 are electrically connected to the cord 11 by pressing the

prongs

41, 43 through the jacket25 and into the

conductors

21, 23, respectively. The jacket material, as described above, is soft and easily penetrable and allows the prongs to pass easily therethrough. After the

prongs

41, 43 penetrate the outer layer of the jacket 25, they enter the

conductors

21, 23 by way of the randomly spaced apertures 29,between the individual wires 27.

The apertures 29 generally are smaller than the thickness of the

prongs

41, 43; however, the flexible nature of the wires 27 and that of the wire Iatticework forming the

conductors

21, 23 allows sufficient give so that the

penetrating prongs

41, 43 expand successive ones of the apertures 29 transversely through the

conductors

21, 23 and cause them to generally align with one another. This allows the

prongs

41, 43 to easily pass into and substantially through the

conductors

21, 23 as seen in FIG. 2. At the same time, the wires 27 grip the

prongs

41, 43, as shown in FIGS. 2 and 4, and hold the prongs in place in the

conductors

21, 23 to maintain good electrical contact therewith. The jacket 25 tightly grips the

prongs

41, 43 and electrically protects them.

In some cases, such as with the newer miniature decorative lights, the holding power of the wires 27 and the jacket 25 on the

prongs

41, 43 is sufficient to support the members 35. However, it may be necessary or desirable to provide the load members 35 with additional holding means such as

contoured gripping fingers

45, 47 which releasably grip the sides of the cord body 13, as shown in FIGS. 1 and 2.

The load members 35 are removed from the cord 11 simply by manually pulling them away therefrom. When the

prongs

41, 43 are withdrawn, the wires 27 relax back to their original shape. Also, because of the inherent cold flow chacteristics of the jacket 25, it basically regains its original state and reseals the openings fromed by the

prongs

41, 43. Thus, the cord 11 can be used again and again and the load members 35 can be moved around as desired with complete safety. Further, the load members 35 are readily connected to and disconnected from the cord 11 quickly and easily and without requiring any tools of any kind.

As described above and shown in FIG. 1, the cord 1 l is connected to a suitable A.C. electric power source by means of the male plug connector 15. In some cases, it may be desirable to utilize less voltage than is normally available at these sources. Such may bethe case with the miniature decorative lights referred to above. There it may be desirable to utilize on the order of 3.5 volts, rather than the normal house voltage of volts. To this end, the male plug may have a stepdown transformer (not shown) built directly into it to reduce the voltage in the

conductors

21, 23 to the desired level. Of course, it will be appreciated that the invention is not so limited.

Furthermore, it will be appreciated that the number and gauge of the wires 27 can and will vary according to the current and voltage chacteristics required in the particular installation. The invention, of course, contemplates three conductor cords as well as the two conductor cord shown.

Turning now to FIG. 5, shown there are two cords 11A and 11B electrically connected by a splicer 51. The cords 11A and 11B are laid side by side and are held togetherby a pair of contoured, flexible retaining fingers formed integral with the splicer 51. A pair of

conductive metal prongs

57, 59 have their heads embedded in the insulating splicer member 51 and penetrate the cords'llA and 11 B to electrically connect

conductors

21A and 21B, and 23A and 238, respectively, when the splicer 51 is in place. As was the case with the cord 11, the jackets 25A and 25B have good cold flow characteristics and effectively self seal the openings therein when the splicer 51 is withdrawn. Thus, as many individual cords 11 as desired may be quickly and easily joined together and disconnected at will.

The method of the preset invention is illustrated schematically in FIG. 6. As shown there, a series of wires 27 are continuously fed to a forming station A which includes one or more sets of cooperating gearlike

cogged wheels

61, 63. The wires 27 emerge from station A with a zigzag configuration as shown, and move into station B where some of the wires 27 are displaced longitudinally relative to one another. This may be achieved by feeding some of the wires 27 along a straight line path, and others over

idler rollers

65, 67, 69, 71 spaced different distances from the straight line path.

Next, the wires 27 reconverge to a set of two (or three) conductors at station C where the jacket 25 is continuously extruded thereover. Emerging from station C is the finished cord 11 which is then cut to length. One end of the cord 11 then has a male plug 15 secured thereto while the other end is sealed off.

It will be understood that a certain amount of tension is needed todraw the wire from station A through station C. Thus, to insure that sufficient kink remains in the wires 27 as the jacket 25 is extruded thereover, the wires may be over kinked at station A. Only approximately 5 to 10 lbs. pull is needed to feed the-wires 27 through the system and this is easily accommodated.

By the foregoing, there has been disclosed a preferred form of the invention; however, various additions, substitutions, modifications, and omissions may be made thereto without departing from the spirit of the invention.

What is claimed is:

1. An electric power cord comprising a plurality of conductors encased and separated by an insulating jacket, each said conductor including a plurality of elongated conductive filaments extending generally longitudinally of said cord, said filaments of each said conductor being juxtaposed and substantially each said filament being deformed laterally of said cord substantially throughout their length and relative to a large number of the other of said filaments, whereby to define a series of random apertures therealong, said insulating jacket being formed of a soft, pliable and easily penetrable material.

2. An electric device comprising an elongated cord having a plurality of spaced, parallel conductors extending substantially throughout its length, means at one end of said cord for connection of said conductors to an electric source, said conductors including electrically conductive filaments defining an open lattice having randomly spaced, relatively small apertures substantially continuously along their length, a sheath of easily penetrable, self-sealing insulating material encasing said conductors, said cord receiving one or more pronged. electric load members along its length by manually pressing said prongs through said sheath and into the apertures in said conductors, said filaments being disposed within said sheath for limited movement relative to one another when engaged by said prongs whereby to permit said apertures to shift, said sheath material being constructed to snugly grip said prongs to support and retain said load members and electrically protect said prongs, said sheath material being further constructed to reclose the openings formed therein by said prongs upon removal of said load members from said cord.

3. An electric power cord comprising a plurality of conductors formed from elongated conductive filaments laterally deformed regularly along their length, said filaments of each said conductor being displaced longitudinally of others of said filaments, wherebyto define random, irregular apertures transversely through said conductors substantially continuously throughout their length, said conductors being encased by a sheath of pliable, easily penetrable material having inherent cold flow chacteristics.

4. An infinite female connector comprising two or more elongated conductors encased and separated by a jacket of relatively soft, pliable insulating material, said penetrate respective ones of said conductors by way of aligned ones of said apertures, said jacket material reclosing and resealing the openings formed in said jacket by said prongs upon removal of said prongs therefrom.

5. The method of making an electric power cord comprising the steps of selecting a plurality of elongated, laterally deformed, electrically conductive filaments, arranging the filaments in spaced sets with the filaments of each set juxtaposed and the lateral deformations of each said filament being displaced longitu dinally of the lateral deformations of a large number of the other of said juxtaposed filaments to definespaced, random, irregular apertures along said set, and encasing said filaments sets with an easily penetrable insulating material.

6. The method of making an electric power cord comprising the steps of laterally kinking a plurality of tioned such that the kinks of adjacent wires are displaced longitudinally of one another, whereby to form said apertures.

8. A device as defined in claim 2 wherein said apertures extend irregularly transversely through said con I ductors, said apertures being generally smaller than said prongs, whereby said prongs expand said apertures and are gripped by said filaments.

9. A device as defined in claim 8 wherein said filaments comprise conductive wires extending substantially the length of said cord.

Claims

2. An electric device comprising an elongated cord having a plurality of spaced, parallel conductors extending substantially throughout its length, means at one end of said cord for connection of said conductors to an electric source, said conductors including electrically conductive filaments defining an open lattice having randomly spaced, relatively small apertures substantially continuously along their length, a sheath of easily penetrable, self-sealing insulating material encasing said conductors, said cord receiving one or more pronged electric load members along its length by manually pressing said prongs through said sheath and into the apertures in said conductors, said filaments being disposed within said sheath for limited movement relative to one another when engaged by said prongs whereby to permit said apertures to shift, said sheath material being constructed to snugly grip said prongs to support and retain said load members and electrically protect said prongs, said sheath material being further constructed to reclose the openings formed therein by said prongs upon removal of said load members from said cord.

3. An electric power cord comprising a plurality of conductors formed from elongated conductive filaments laterally deformed regularly along their length, said filaments of each said conductor being displaced longitudinally of others of said filaments, whereby to define random, irregular apertures transversely through said conductors substantially continuously throughout their length, said conductors being encased by a sheath of pliable, easily penetrable material having inherent cold flow chacteristics.

4. An infinite female connector comprising two or more elongated conductors encased and separated by a jacket of relatively soft, pliable insulating material, said conductors including juxtaposed electrically conductive filaments movable relative to one another and defining randomly spaced, relatively movable apertures disposed substantially continuously along their length, means for connecting two of said conduCtors to an electric source, said jacket having good cold flow chacteristics and being easily penetrable by conductive prongs of an electrically conductive member to allow said prongs to engage and move said filaments and penetrate respective ones of said conductors by way of aligned ones of said apertures, said jacket material reclosing and resealing the openings formed in said jacket by said prongs upon removal of said prongs therefrom.

5. The method of making an electric power cord comprising the steps of selecting a plurality of elongated, laterally deformed, electrically conductive filaments, arranging the filaments in spaced sets with the filaments of each set juxtaposed and the lateral deformations of each said filament being displaced longitudinally of the lateral deformations of a large number of the other of said juxtaposed filaments to define spaced, random, irregular apertures along said set, and encasing said filaments sets with an easily penetrable insulating material.

6. The method of making an electric power cord comprising the steps of laterally kinking a plurality of substantially continuous conductive filaments, displacing at least some of said filaments longitudinally relative to others and arranging said filaments in laterally spaced sets, whereby to form random, irregular apertures substantially continuously throughout their length, and continuously encasing said spaced sets of filaments with an easily penetrable, electrically insulating material.

7. A cord as defined in claim 1 wherein said filaments comprise elongated wires formed with alternate kinks defining a zigzag configuration, said wires being positioned such that the kinks of adjacent wires are displaced longitudinally of one another, whereby to form said apertures.

8. A device as defined in claim 2 wherein said apertures extend irregularly transversely through said conductors, said apertures being generally smaller than said prongs, whereby said prongs expand said apertures and are gripped by said filaments.