US2875421A - Electrical trunk line and connector - Google Patents

Description

Feb. 24, 1959 J. JORDAN 2,875,421

ELECTRICAL TRUNK LINE AND CONNECTOR Filed May 20, 1954 2 Sheets-Sheet 1 INVENTOR l/OJEPH J 0;?04/1 Fig.1.. gm wg TTORNEYS Feb; 24, 1959 J. JORDAN ELECTRICAL TRUNK LINE AND CONNECTOR 2 Sheets-Sheet 2 Filed May 20, 1954 INVENTOR JOSEPH JORDAN V; M n, A TORNEYS United States Patent 2,875,421 ELECTRICAL TRUNK LINE AND CONNECTOR Joseph Jordan, Oakland, Calif. Application May 20, 1954, Serial No. 431,095 2 "Claims. (Cl. 339-22 The present invention relates to an improved system of display lighting particularly adapted to the lighting of Christmas trees or the like where a relatively large number of light bulbs are required to be placed in a variety oflocations about or upon an objectto be illuminated.

Various applications of lighting systems require a high degree of flexibility of the system as in the ornamentationof Christmas trees wherein conventional systems necessitate the use of large amounts of wiring to energize lightbulbs disposed as desired throughout the tree. The present system. provides maximum flexibility of lighting systems of this type through the use of wiring means having a multiplicity of simple connections. In particular the present invention provides an improved trunk line adapted to ..receive in electrical connection branch cords having light bulb receptacles thereon; This trunk line is constructed to receive said branch cords in connection at substantially any place along its length, i. e., the trunk line substantially comprises an elongated connector so that no matter what combination or spacing of branch cords is'desired the trunk line readily accommodates same.

It is an object of the present invention to provide an improved lighting system. including a plurality of branch cords and a trunk line adapted to receive same in electrical connection at substantially any point thereon.

It is another object of the present invention to provide an improved lighting system having a flexible trunk line comprising a continuous conductor with integral electrical connection means over the entire length thereof for branch cord connection thereto.

It is a further object of the present invention to provide an improved lighting system having a flexible elongated trunk line including continuous electrical conductors therethrough and adapted to receive branch cords in electrical connection therewith on all sides of the trunk line for the entire length thereof.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part ofthe specificationf It is to be understood, however, that variations in the showing made by the said drawings and description may he adopted within the scope of the invention as set forth in the claims.

The invention is illustrated in the accompanying drawingswherein:

;Figure--l shows a portion of a lighting system in ac cordance with the invention in position upon a Christmas tree; -Figure 2 is a perspective view of part of a trunk lin partially broken away to show interior details thereof.

Figures 3, 4 and 5 are perspective v iews of alternative embodiments of the trunk line of the present invention.

Figure 6 is a center longitudinal section of a branch line connector with the portions thereof separated.

Figure 7 is a sectional view taken at 77 of Figure 6 with the portions thereof in engagement.

Figure 8 is a center longitudinal section of an alternative connector embodiment with the portions thereof separated. a

Figure 9 is a sectional view taken at 9-9 of Figure 8 with the portions thereof in engagement.

Considering now the invention in some detail and referring first to Figure l of the drawings there is shown somewhat diagrammatically a Christmas tree 11 having a central vertical trunk with spaced outwardly extending branches which are to be illuminated. The lighting system of the invention includes one or more elongated trunk lines 12 with conventional electrical plugs 13 at the ends thereof whereby the lines 12 may be energized from floor plugs or the like and whereby a number of lines may be electrically connected in series. The trunk lines 12 define a plurality of female connectors 14 closely spaced along the entire length of each for receiving in electrical connection a plurality of branch cords 16. The branch cords each include miniature male electrical connectors on at least one end thereof for mating with any of the female connectors integral with the trunk line 12 and the branch cords may be provided in different lengths with one or more light bulb receptacles 17 on each whereby light bulbs 18 inserted therein are energized through the trunk line 12. It is contemplated that the trunk line shall be formed of a flexible material such as rubber or the like surrounding electrical conductors and a hook 19 is firmly anchored to one end of at least the upper trunk line of a set for hanging same from a top limb of the tree 11. The branch cords 16 are also flexible so as to be easily wound about the branches if desired.

Considering now the preferred construction of certain elements of the system and referring to Figure 2, the trunk line 12 is therein shown as including an elongated housing 21 of substantially rectangular cross section with a pair of parallel electrical conductors 22 extending longitudinally therethrough. The housing 21 is substantially solid and formed of a flexible electrically insulating material such as rubber. In the interest of minimizing the cross sectional size of the trunk line 12 the conductors 22 are disposed close to one of the sides thereof and there is defined by the housing a plurality of pairs of transverse apertures 23 with each aperture extending from one conductor to the housing side farthest therefrom, as shown. The pairs of apertures are equally spaced along the entire length of the trunk line to provide a maximum flexibility of electrical connection thereto. Within each of the apertures 23 there may be provided clamping means'24 having for example the form of a U-shaped metal strip disposed about the conductor 22 and extending into an aperture with the strip ends deformed to form resilient clamping means. Miniature male electrical connectors on the ends of the branch cords 16 are connected to the trunk line merely by pressing the prongs thereof into the female connectors formed by each pair of apertures 23 whereby the branch cords are electrically connected across the conductors 22 of the trunk line for energization therefrom.

Figure 3 shows a further trunk line construction in whichthe conductors 22 are disposed substantially equidistant from two opposite sides of the housing 21 which in this case preferably has a rectangular cross section with two sides longer than the other. In addition to the apertures 23 extending-to the conductors 22 from one of the shorter housing sides a second plurality of pairs of apertures 26 extend from the conductors 22 to the opposite housing side, as shown. The trunk line housing is in this case somewhat larger in one cross sectional dimension so that an adequate aperture length is provided for arne t proper gripping of male connectors and somewhat different clamping means 27 may be herein employed with same including a pair of metal strips disposed one on each side of each conductor and extending in both directions therefrom within opposite apertures 23 and 26 with the strip endsdeforrned as shown to clamp the prongs of male electrical connectors inserted in the female connectors defined by the pairs of apertures.

Figure 4 shows a further trunk line structure somewhat similar to the embodiment of Figure 2 with the conductors 22 disposed adjacent one housing side but with longitudinally spaced removable housing side portions 28 hearing lengths of the conductors 22 within the housing. These housing portions may be secured to the remainder of the housing by bolts 29 having large pitch threads gripping the sides of transverse housing openings 31 and the removable portions 26 are disposed in line with the housing apertures as for facilitating the joinder of clamping means 32 to the conductors 22. These clamping means 32 are disposed one in each of the apertures 23 of each pair thereof and are similar in structure to those of Figure 2 with a substantially Ueshaped configuration but not extending about the adjacent conductor 22; A part of the clamping means is unfolded to extend beyond the bottom of the U and this is joined to the conductor in electrical contact therewith, as shown.

One further trunk line embodiment is illustrated in Figure and in this instance for the purpose of minimizing the trunk line cross section the conductors 2 2 are laterally spaced on a diagonal of the trunk line housing cross section which is substantially square. Pairs of apertures are formed in each side of the housing 21 and considering the section illustrated, one aperture 33 is quite long while the other aperture 34 is short in that the conductors 22 are not equally spaced from the housing side in which these apertures are formed. The pairs of apertures are spaced along each side of the trunk line housing, as shown, and clamping means such as that of Figure 2 are provided, however, one of the clamps 36 is longer than the other clamp 37. The longer clamp 36 in the long aperture 33 provides a sufficient gripping action to make up for any lack thereof in the shorter clamp 37. A slightly different male connector 3? is employed with this trunk line embodiment in that a pair of prongs 41 and 42 of unequal length are provided thereon for mating with the apertures of unequal length. In order to plug the connector into the opposite side of the trunk line; it is only necessary to reverse the prong position by rotating the connector ninety degrees.

In addition to the above noted structures of the trunk line, various difierent connectors may be provided for branch cord to trunk line connection and branch line to branch line connections. Referring to Figures 6 and 7 there is shown a connector including a male portion 43 and a female portion 44 with each being preferably formed of an insulating material such as molded rubber vulcanized to the remainder of the branch cord for examplel The male portion 43 includes a pair of parallel blades 46 extending from the end thereof and electrically connected internally thereof to separate conductors of the cord as by looping the conductors through the inner blade ends. The female portion 44 has a pair of parallel longitudinal slots aligned with said blades 46 for receivingsame and each having narrow U-shaped strips .47 therein deformed as shown to clamp the inserted blades and separately connected at their inner ends to individual conductors of the cord.

These connectors may be alternatively formed as shown in Figures 8 and 9 by providing in a male portion of rubber or the like a pair of extending rigid cylindrical prongs 49 which are connected internallyof the portion to separate conductors of the cord, as shown. A flexible female portion 51 of the connector includes a pair of parallel apertures 52 within each of which there is disposed a hollow split metal cylinder 53 with each connected to separate conductors of the cord. The apertures 52 have a slightly smaller diameter than that of the cylindrical prongs 49 so that insertion of the latter in the former expands the cylinders 53 radially outward to assure a firm grip between the two portions of the connector.

The lighting system and elements thereof described above will be seen to provide a maximum degree of flexibility in that substantially any desired lighting arrangement may be attained with a minimum of wire so that in the illumination of such as a Christmas tree, for example, the wiring is substantially invisible. In this respect it has been found advantageous to form the connectors of a smaller size than conventional electrical plugs and as an example theconnectors of Figures 6 -9 may have a diameter of V inch with each portion thereof having a length equal to its diameter. Similarly the .trunk line need only have a maximum cross sectional dimension of inch with the apertures therein being Mi inch apart and pairs of apertures being spaced about an inch apart. Additional flexibility results from the provision of trunk lines and branch cords ofdifierent lengths, as above noted, and in connection with the illumination of Christmas trees, trunk lines of two and three feet in length are advantageous while branch cords of one, one and onehalf and two feet provide for most contingencies. 'Although innumerable different combinations of dimensions are possible those set out above are found admirably suited for Christmas trees inasmuch as an entire system covering any size tree with lights is readily accommodated by the tree structure and can hardly be seen. among the foliage thereof.

What is claimed is: r

1. An improved trunk line for a lighting system comprising an elongated flexible electrically insulating housing of substantially solid rectangular crosssection, and a pair of parallel electrical conductors disposed longitudinally Within said housing substantially upon a diagonal of the cross section thereof, said housing having means defining a plurality of pairs of laterally spaced apertures disposed along the length of each side of said housing in communication with said conductors from exteriorly of said housing and defining a plurality of integral female electrical conductors on each side of said housing and spaced along the entire length thereof.

ZJAn'im'proved lighting system comprising an elongated flexible' electrically insulating trunk line having a substantially uniform rectangular cross section with a pair of parallel electrical conductors extending longitudinally therethrough and spaced apart on a diagonal of the trunk line cross section, said trunk line defining a plurality of pairs of apertures equally spaced along each side thereof and extending transversely into communication with said conductors, and each pair of apertures including one long aperture and one short aperture extending to the respective conductors.

References Cited in the file of this patent UNITED STATES PATENTS 1,067,024 Hall et al. July 8, 19.13 1,568,156 Herskovitz Jan. 5, 1926 2,089,856 Reynolds Aug. 1Q, 1937 2,481,181 Walter Sept. 6, 1949 2,533,222 Cohen Dec: 12, 1950 2,558,029 Wood June 26, 1951

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