US2810115A - Connectors for lamp cords - Google Patents

Description

Oct. 15, 1957 c. w. ABBOTT 2,310,115

CONNECTORS FOR LAMP CORDS Filed Aug. 22, 1955 ff. M

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2,810,115 CNNECTRS FOR LAMP CORDS Charles W. Abbott, New Rochelle, N. Y., assignor to Abbott Deveiopments, inc., New Haven, Conn., a cor poration of Connecticut Application August 22, 1955, Serial No. 529,877 2 Claims. (Cl. 339-97) This invention relates to means for electrically connecting two lamp cords, especially duplex lamp cords, and this application is a continuation in part of copending application 216,542 tiled March 20, 1951, now abandoned.

The term duplex lamp cord is well known in the trade and is used to mean a cord comprising two conductors arranged side by side in parallel relation and untwisted. it will be understood that these duplex cords are employed for connecting a wide variety of objects in a house lighting circuit and the like, such for exampie as electric table and iioor lamps, radios, electric clocks and similar devices.

It is often desirable to interconnect two lamp cords, either to extend the length of one cord, or to replace a worn out length or" cord. This is particularly true in the home but housewives although wanting to make such connections have usually hesitated to do so feeling that it is an electricians job, requiring, as it has, tools for taking apart and reassembling the bulky connection devices employed, for trimming oif the ends of the cords, baring the wires of cord conductors, etc. Usually it has been necessary to secure wires of cord ends under binding posts or to twist together cord Wire ends, if the connection was made directly without a connecting device, and this last operation required the further step of taping the twisted together wires to insulate the conductors of each cord from one another and to provide an insulating covering over the interconnected cord ends. In addition to being difficult for the ordinary housewife to use, such connector devices for duplex cords as have heretofore been available have been bulky and unsightly and involving male and female members each of which must be connected to conductor ends before they can be connected to one another.

lt has heretofore been suggested to interconnect the ends of two conductors by pushing them axially upon the respective pointed ends of a conductive pin within a tube or channel, and to prevent the conductors being inadvertently pulled off the points of the pins by clamping the conductor ends between opposed ribs contacting the conductor on opposite sides within the tube or channel. However, at the present time lampcords differing widely in diameter are available in the market and obviously ribs which are xed in position and which provide a satisfactory grip on conductors of one diameter provide less of a grip or no grip at all when conductors of smaller diameters are employed. Furthermore, the cords of greater diameter were usually insulated with a rubber composition which even though vulcanized could be penetrated by the ribs to a greater extent than the insulation of the newer cords insulated with plastic compositions. The prior art connectors employing relatively straight pins to make contact between the conductor ends and employing opposed ribs to lock the conductor ends on the points of the connector pins are no longer satisfactory.

Accordingly it is an object of this invention to overcome deciencies of the prior art and provide means for connecting one duplex lamp cord to another which are simple, practical and inexpensive.

Another object of the invention is to provide means of the above mentioned kind which will be simple and quick to use without requiring the use of any tools.

Another object of the invention is to provide connection devices which are small, strong and of pleasing appearance.

Other objects of the invention will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features 0f construction, combinations of elements, arrangements of parts, and in the several steps and relation and order of each of said steps to one or more of the others thereof, all as will be pointed out in the following description, and the scope of the application of which will be indicated in the following claims.

The invention will be best understood if the following description is read in connection with the drawings, in which,

Figure 1 is a perspective View of one form of duplex cord connecting device in its actual size;

Figure 2 is a perspective view on an enlarged scale showing the inner face of the cover;

Figure 3 is a perspective view of the inner face of the bottom or body member shown in Figure l;

Figure 4 is a plan view of the device partly broken away;

Figure 5 is a side cross sectional view taken on the line 5-5 of Figure 4;

Figure 6 is a transverse line 6-6 of Figure 4;

Figure 7 is a transverse cross sectional view taken on the line 7-7 of Figure 4;

Figure 8 is a side elevational view on a somewhat enlarged scale of one of the pins having hooked ends embodying my invention.

Figure 9 is an end view of one of the hook ends.

Figure l0 is a sectional view taken on the line 10--10 of Figure 8.

ln Figures 1 to 10 inclusive there is shown a device for electrically connecting two duplex lamp cords, Figure l showing the device in its actual size and the other figures showing it on an enlarged scale. This device serves to extend the length of one duplex cord by joining another length of cord to it. it comprises a body member 10, and a cover member 12, each of which is thin and narrow, and each of which is grooved on its inner face with two pairs of channels, those illustrated being part round or substantially semi-circular channels, those of one pair being aligned with those of the other pair respectively in end to end relation, but terminating short of one another leaving a transverse middle line. The channels in the cover are disposed so that when the cover member 12 is positioned on member 10 they will complement those in the member 10, thereby providing space for the conductors comprising a duplex cord.

As shown herein the bottom member 10 is grooved on its inner face with the substantially semi-circular pairs of channels Ma and 16a, and 15a and 17a. Channels 14a and 16a have common end opening 13a and then fan apart inwardly. Similarly channels 15a and 17a have the common end opening 20a and then fan apart inwardly, the inner end of channel 15a being aligned with the inner end of channel 14a but spaced from it by the transverse web 24, and the inner end of channel 17a being aligned with the inner end of channel 16a but being spaced from it by the transverse web 26.

Extending through and locked into the transverse webs 24 and 26 are the conductor pins 28 and 30 respectively, the ends of which are bent to form hooked shaped con-` tacts which are substantiallyl wedge shaped in horizontal sectional view taken on the 3. cross section. The points of the hook end portions of the pins taper to the top and each has a thin outer face x and side walls y diverging to :a thicker inner face z. The rear .face z -is preferably'substantially at to resist the conductor being pulled olf the point of the hook by a force exerted substantially .axially ,of the pin. The .pins are snpported so .that their pointed .ends 28a and 2819 and 30a and 30h are in full view and are positioned substantially along the center line of the channels into which they project, when the members l@ and 12 `are assembled. As shown herein the webs are slotted with a canter locking .offset and the pins are forced fitted into them. The ends of the pins ,are preferably swedged in the ,same operation in which the canter is formed and as the wire from which :the pins are formed is cut into lengths, ,and .bent into hook form by die as the pins are set in said webs and downset to cause the bottom of the hooks to rest on the surrounding channel wall.

The cover 1 2 is similar in shape and size to the member 10, but has no conductive pins assembled therein. Its inner Vface is grooved with the part round or substantially semi-circular pairs of channels 14h and 16h, complementary to the grooves 14a and 16a in the inner face of member 10, and 15b and 1711, complementary to the grooves 15a and 17a in the face of member 10. Channels 14b and 16b have the common end opening 18h and then fan apart inwardly. Similarly channels 15b and 17b have the .com-mon end opening 20h and then fan apart inwardly. The inner end of channel 15b is aligned with the inner end of channel 14b but spaced from it by the transverse web 31, and the inner end of channel 17b is aligned with the inner end of channel 16b but spaced from it by the transverse web 32.

In Ithe cover member 12 screw holes h are provided extending through the area between the channels 14h and 16b and between the channels 15b and 17b, the outer ends of said holes being enlarged to receive the heads of screws vs which are counter-sunk therein. In the body member screw holes h are provided, extending through the area between the channels 14a and 16a, and between the channels a and 17a and similarly positioned to the screw holes h in the cover member so that when the cover member is assembled to the body member the screw holes h in the cover member will be aligned and in register with the screw holes h in the body member. As shown herein the screw holes h' in the body member are internally threaded to engage the lower ends of the screws s respectively.

Preferably the head of each screw s is provided with turning slots of a width to receive the edge of a coin, for example a ten cent piece, or a knife blade, nail tile or the like for turning the screw. No other tool is necessary and the operation of connecting one duplex cord end to another may be performed very readily by a housewife without tools, and without having to bare the ends of the conductors and twist them together and thereafter insulate them with tape, or without having to bare the en ds of the conductors and secure them to binding posts with the screwing and unscrewing of the binding posts which is involved when prior art connectors using such posts are employed.

In .connecting the duplex lamp cords with the connection device described above the ends of the two conductors .comprising each of the cords to be connected are separated and the conductor ends comprising one cord are positioned within the grooves 14a and 16a, and pushed down on the hook ends 28a and 30a of the conductive pins -28 and 30 respectively, causing the hooks to penetrate Tand .extend well into .the center of the bundles of wires comprising the conductive cores of said conductors and lto be well imbedded therein with the Hat faces of the hooks within, and spaced from, the inner .extremities of the conductors respectively. The wires comprising a -condnctor end `are usually twisted and ,tend tolclose around the ,inserted hook point. The .ends of the conductors comprising the other duplex cord are then brought into said channels 14a and 16a from the direction of the end opening 20a and pushed down on the hook ends 28b and 30h of said pins 2S and 30 until the said hooks have penetrated well within the cores of said conductors. The housewife or other person making the connection in performing this operation with the means disclosed herein is able to see the contact points at the time they enter the conductors and thus make certain that the conductive cores of the conductors are well engaged by the hook ends of the pins respectively. It will be noted that the device disclosed herein has that advantage and that many of the wires comprising the core Yof a conductor are in contact with the hook end which has been inserted among them, and that this contact is not just a point contact as is the case when a wire is tangent to a round pin, but extends the full length of the diverging side walls of the hook, Aand provides a contact meeting the 7 amperes overload test of the Underwriters Laboratories. The width ofthe hooks is proportioned to the diameter of the channels inwhich the conductor ends are respectively received so that when the wires comprising a conductor end are forced' apart by the insertion of .a hook contact of the kind disclosed herein they are pinched and rmly held between the lateral edges of the flat face of the hook i. e. the widest part Vof the hook contact, and the surrounding channel wall. Differences in the diameters of conductors are compensated for lby pushing the point of the hook Contact further through the conductor thus increasing the width of the portion of the contact which enters the conductor and expands the `bundle of wire comprising it. The deficiency of the prior art devices in dealing with conductors of different diameters is thus overcome.

After the conductor ends of both duplex cords have been pushed down on the points of the hook ends of said pins 28 and 30 respectively the cover 12 is screwed onto the body 10.

Within the channels 14a and 16a and 15a and 17a and adjacent theprrespective outer ends thereof a pair of ribs r are provided, the said ribs projecting part way into the space .dened by the channels, and in channels Mb and 16h, and 15b and 17b, adjacent the respective outer ends thereof a single rib r is provided, positioned so that when the top and bottom parts 10 and 12 are assembled together a rib in each channel of member 12 will lie between the ribs in each channel of member iti whereby .the conductors in said channels will be engaged on opposite surfaces and `given a sinuous form. The provision of such ribs is not new and as stated above .the prior Vart relied on thein almost entirely to provide a mechanical engagement strong enough to meet the 3() lb. strain test of the Underwriters Laboratory, but much less dependence can now be placed upon this means in View of the wide variation inthe diameters of lamp cord conductors now on the market. I prefer however, to employ such ribs in combination with the means disclosed herein for gripping the wires comprising a conductor between the sides ofthe hook contacts and the surrounding channel walls. very good results with the structure disclosed herem and have had no diculty in meetingl the Underwriter Laboratorys 30 lb. strain Relief Test.

In this way a very rm dependable connection is proends of two duplex cords in a very simple way, and the whole operation may be performed visually and very quickly, without the need of any skill, and without the use of any tools other than the use of a coin, knife blade, nail le or the like for tightening or loosening the screws s, and the resulting coupling is not .only effective but very strong, of small size and pleas ingappearance.

There has thus been provided an improvement in duplex lamp cord connecting devices in which the lvarious objects hereinabove set forth together with many thor- Oughly practical .advantages i-are successfully achieved. As various possible lembodiments might be made of the 5 mechanical features of the above invention and as the art herein described might be varied in Various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

What I claim is:

1. A device for electrically connecting one duplex lamp cord to another which comprises, two parts each grooved with semi-cylindrical grooves to receive in alignment the double ends of two lamp cords to be connected, and means for securing the parts together with the grooves of one part coacting with the grooves of the other part to provide tubular channel means for receiving the `opposed ends of the conductors to be connected, two pins mounted in one of said parts, with each pin extending axially of one of the said channel means to engage the twisted bundles of wires comprising the cores of opposed lamp cord conductors, the end portions of each of said pins being bent at an angle to the center portion of the pin for insertion in the ends of opposed aligned conductors respectively, each bent end portion of said pin having a wide inner surface normal -to the body portion of the pin and having side surfaces inclined toward one another outwardly of the pin and meeting in a sharp edge facilitating insertion of the end into the core of a conductor, the wide inner surface of each bent up end portion of the pin serving to resist apull tending to pull conductor end otr the pin end.

2. The device of claim 1 in which each of the substantially semi-cylindrical grooves in the part in which said pins are mounted is divided into two axially aligned grooves by a transverse web comprising part of the said part, and said pins are mounted within said transverse webs respectively, with their opposite ends extending into the aligned and opposed groove portions respectively, with their bent up portions extending from the bottom of said groove portions respectively through the longitudinal center line of said grooved portions respectively.

References Cited in the tile of this patent UNlTED STATES PATENTS 527,184 Richey Oct. 9, 1894 2,525,449 Contant Oct. 10, 1950 2,567,783 Richardson Sept. 11, 1951 2,675,531 Sams et. al. Apr. 13, 1954

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