US2647245A - Readily attachable electrical connector - Google Patents

Description

July 28, 1953 c. E. GILBERT READILY ATTACHABLE ELECTRICAL CONNECTOR File'd Sept. 28, 1949 2 Sheets-Sheet l ATTORNEYS l 8, 1953 c. E. GILBERT 2,647,245

READILY ATTACK-{ABLE ELECTRICAL CONNECTOR Filed Sept. 28, 1949 2 Sheets-Sheet 2 i=l.l7. 91 gas)? 92 INVENTOR. CHARLES GILBERT 0m 43% ATTORNEYS w p W m EF 3" 1 o i m Q. ll! it y 6 6 w a 1 6 J; 2 1 1m? ////////1 w w m. Ww F f H m w MZ/ M 1 a8 W 7%: WW I. 0//////A//NflA// -I a; 0 8

Patented July 28, 1953 UNITED eATENT OFFICE Application September 28, 1949, serial no. 118,256

5 Claims.

The present invention relates to newva-nd' use: ful improvements in electrical connectors of the type used for making an electrical connection between electrical two-conductor lines, where, for instance, one of said lines is connected to an 5 electrical supply outlet and the other to a cord for an electrical appliance. I I

Theprincipal ob'jec'tof the invention is to provide improved forms of electrical connectors or this type which can be made of aminim'um miniher of parts and produced at a minimum cost and which-permit the cord to be coupled to the con hector by the user in a ready and simple" manner.

Another object of the invention is to provide connectors of this type'in which the contact e1ements thereof may be" securely positioned and held in the connector body correct alignment and in secure contact with a conductor c'or'dwithout the use of screws, rivets, or other seeming devices. I I

A further object is to provide an electrical con"-- nector construction in which the contact elements thereof are simply positioned in the con nector'hody' and in which the connection of the conductor cord to the contact elements may be readily made without requiring any separation or stripping of the respective" conductors of the cord.

Still another object is to' provide electrical connectors which can be easily assembled anddis'- assembled without the exercise of any particular mechanical skill and without requiring tools therefor.

It is still a further object to providetelectrical connectors of thetypes above referred to either 3'33 of the male or female types. I

Yet another Object of the present invention" is" to provide an improved and simplified device for connecting a plurality of appliances or cords to a single cord, to permit use of a single electrical outlet receptacle for such a plurality of appli anees or cords. I

Further objects and advantages of the present invention will become more apparent: frond con sideration of the following description of p' f'erre'd' forms thereof taken in conjunction the appended drawings, in Which-=- Figure 1 is a longitudinal cross-sectional as sembi'y view of a plug'andit's connected cord; in accordance with the present invention; viewed along=line l---i' ofFigur'e 2; I I

Figure 2 is a transverse"cross sectionalview'of the apparatus of Figure l; takenalon'g line- 2- thereof;

FigureS is a top view of the plugof Figure 1 55" stitu-ted for that of- Figure 10;

-- PS t-E of Figure 14; and- 2 v v with the cover removed and without the conductdr'corci in place; I Figiire i is a cross-sectional view of the plug taken-along lit'iedtof Figure 1-; I I Figure 5 is a bottom view of the plug coyer partly in section, taken along line 5-=-5 of Figure 1; V

Fig-tire 6 isari elevation end view of the plug" assembly of Figure I viewed from the left side of Figure I; s I Figure 7 is another elevation end; view or plug; assembly ofthe present invention viewed fromthe right of Figure, 1,- and without the condnotor cord; i I I Figure '8- is' a side elevation view of theplug body contact assembly of the invention, omitting the-cover; I I \I I Figure 9' is an end view ofthe'device o fFi'gure 8' viewed from the right thereof; I I I Figure 10 is a developed or unfolded vie of the contact element used in the plug of Figures 1 to 9-;

Figuredr isasimilardeveloped of a r'fio'd ified formof contact; element which may be set Figure 121s asimilar view of; still another egatact'element which may be substituted for either of those 0% Figure 10 or- Figure 11; II II I Figure 1-3 is a-transverse-end- -view of amodjified form of the device of Figures- 1 to 9; II

Figure 14" is" a longitudinal crossssectional view of a plug receptacle embodyingthe principles of the present invention and viewed along line M -Ht of Figure 15; a

Figure 15 is a transverse cross sectional vieur of camping receptacle along line tfi' lfr of Fig- I Figure 16 is a bottom view of the receptacle and contact assembly viewed along line Figure 17 is a-develeped or unfolded view of a contactelen ent which may be used inthe device of figures 1e to 16. II

Figu-re's l-to- 10 il1ustrate detail a plug assembly embodyingthe present-inventionand adapted tobe readily connected-tea conductor cord This plug assembly comprises-four elements -a-body 24,

a cover- 3g;vand two ideriticalcontactelements or prongs 2t and 12 Referring more particularly to Figure 10, which shows a preierred form of each prong" 23 and 24, each such" prong is suitably form d (asby-p'un'ching and'foldin m a strip" 3 against one another when the prong is folded about a line 21 to produce the lower bend 28 as as shown in Figure 1. One of the portions, such as 25, exceeds the other in length by virtue of a tab 29 and a pair of sharp points 3| formed therein. As shown in Figure l with respect to the prong 24, tab 29 is bent at right angles to he remainder of the prong and assists in positioning r n 24 in the plug body 2 l ie pl ug body 2| is preferably molded from rigid electrically insulating material, such as any of the well-known thermosetting or thermoplastic insulating substances, and is in the form of a generally hollow rectangular casing having a bottom wall 32, end walls 33 and 34, side walls 35 and 36 and open at the top. A plurality of transverse partitions or walls 31, 38 and 39 are provided, which contribute to the rigidity and strength of the plug body and also have additional functions.

as will be described. t

The center partition 33 terminates at its top in an inverted V-shape shown at 4| in Figure 2 and serves to locate the two conductors of the cord to be attached to the plug. Where separate w res are used, this partition 38 positions thesewircs properly in relation to the prongs, to insure proper contact therewith.

Each of the partitions 31 and 39 forms a guide and retaining support for a corresponding one of the prongs 23 and 24. As seen in Figure 1, Just to the outside of each of these walls 31 and 39 a respective slot 42 or 43 is formed in the bottom wall 32 of the plug body 2|, and is adapted to ac commodate a corresponding prong 23 or 24. As will be seen in Figure 4, each of these slots 42 and 43 is formed to have individual guides for each of the portions 25 and 26 of the prong 23 or 24, which is then adapted to be readily slid into the slots 42 or 43 parallel to the partitions 31 or 39. In assembly the punched and folded prong 23 or 24 is inserted into one of the slots 42 or 43 with the longer prong side 25 adjacent the corresponding partition 31 or 39. The top portion 29 of this longer side is then bent over as shown at 29 in Figure l to form a retaining means for the prong, to prevent it from sliding out of the body 2 The points 3|, however, protrude upwardly beyond the ends of the'walls 31 and 39 as shown in Figure 3. This arrangement of the prongs causes the points 3| of prong 23 to lie on one side of the vertex 4| of the inverted V of wall 38 while the points 3| of the other prong 24 lie on the other side of this vertex 4|.

The side walls 35 and 3B of the plug body 2| and one end wall 33 extend beyond the upper ends of the partitions 31, 38 and 39 by an amount approximately equal to the thickness of the conductor cord to be attached to the plug. The other end wall 34 has an opening 46 formed therein sufiicient to accommodate the conductor cord and this opening is located at least partially somewhat below the upper end of the partition walls 31, 39. This opening may be formed merely by shortening wall 34, if desired. Preferably the wall 34 is also made slightly shorter than the other end wall 33 as shown in Figure 7. The plug cover 22 is also formed as a generally rectangular member having a rectangular channel 41 running tberethrough and corresponding closely in dimensions to the transverse cross-section of the plug body 2|, to provide a loose sliding fit therewith. It contains a full top wall and full side walls 52 and 53. One end wall, however (corresponding in location to plug body end wall 33) is completely omitted,

while the other, as shown in Figure '7 (corresponding to the body end wall 34) is but a partial end wall 54. The bottom wall 56 contains a longitudinally extending opening 51 slightly wider than the width of the prongs 23 and 24. On the inside of the top wall 5| of the cover 22 are a pair of spaced projections 58, 59 having gradually sloping connection to the flat inner surface of the 4 top wall 5|. These projections have a depth related to the size of the conductor cord and the points 3| as will now be described.

In assembling the device the conductor cord (which, for example, may be formed of the conventional two-conductor rubber-covered lamp cordor two independent conductors) is merely out to desired size or may be already of suitable size. There is no need to separate the conductors or to strip their ends. The end 6| of the conductor cord 32 is then placed in the recess in the plug body 2| formed by the end wall 33 and partition 31, as shown in Figure l. The conductor cord 62 is then bent at right angles to lie across the length of the top of the plug body 2| in contact with the points 3|. If two separate conductors are utilized the pointed upper wall 4| of partition 38 serves to align each of these conductors against the inside of the side walls 35 and 3B of the plug body in alignment with the points 3| of the prongs 23 and 24. A two-conductor cord is of proper size to position itself similarly. The cover 22 is then placed around the conductor cord 32 and is slid over the plug body 2| with the inwardly protruding edges 33 at the bottom of the cover 22 engaging the bottom wall 32 of the plug body 2|. In so doing the projections 58 and 59 force the respective conductors of the cord 62 into intimate contact with the points 3| which are thereby caused to pierce the insulation of the conductor cord and make electrical contact with the conductive wires. In this way no stripping or separation of the conductors is required, and they are electrically connected to the prongs 23 and 24 in simple fashion. At the same time, the larger end wall 54 of the cover 22 causes the conductor cord 32 to assume an offset position as shown at 63, by creating a double bend at that point which provides a strain relief so that any tension or stress on the cord 62 is taken up by the wall 54, which prevents the stress from being communicated to the contact between the points 3| and the conductors of the cord 52.

In this way there is provided an extremely simple plug arrangement having only three different parts, and only four parts in all, by which a plug can be readily manually connected to a cord without in any way requiring stripping or slitting of the conductors. Therefore, the assembly of the plug on a cord can be performed by anyone, without any tools being required, while still providing good electrical contact between the cord and the prongs of the plug and providing a plug which, when assembled on a cord, will withstand considerable tension or stress without impairing its action. In addition, it will be noted that the cord 62 extends transversely of the plug prongs '23 and 24, so that when the plug is inserted in the usual wall outlet or receptacle the conductor cord 62 tends to lie flat against the wall rather than extending perpendicular thereto in an unsightly fashion as has been characteristic of many prior art devices.

It will be understood that the prongs can be made in a wide variety of forms while maintaining the advantages of the present invention.

scamme- Thus, in place of having both points 3| --on the portion 25, as shown in Figure 1].- a: single point 31 may be formed on portion 25 with a further point- 3la formed onportion. and offset relative to point 3i when the prong is bent. Alterna-- tively, if desired, two points 3% can be: put on portion 25 and two additional points 3I' formed on portion 2-6, or one point can be put on each or two points on; either or a single point on either one. The points on the two portions 25, 26 may be aligned or staggeredany of these. dorms. In addition, instead of forming the prong'by' bendin double as in Figures-- and 11. a S

preferably thicker prong of the desired shape may be used as shown in Figure 12, which prong may have either two points 34- as shown or but a single point or a larger plurality of points.

In order to provide a finger hold. to facilitate entry or removal of the plug. into or from an outlet or receptacle, the side walls 5 2,53- may-be. curved as shown at E6. Alternatively, the structure shown in Figure 13. may be utilized, in. which the cross-section of the plug body has been altered to provide laterally extending portions II and 1.2 at the top which engage the inwardly extend- ' ing portions 13 and 14 of the bottom of cover, which latter portions correspond to elements 55 of Figure By this. arrangement the grasping. of the plug for removal of. or entry into an out.- let is facilitated by providing a, better finger held. In the form shown in Figure 13 the prong arrangament and internal arrangement of. both the cover and the plug body are essentially as in the preceding figures.

Figures 14 to 1'? showanother form of conhector embodying the principles of the present invention. In this. instance, however, the connector is a plug receptacle or female. connector adapted to make connection with either a plug, of the types shown in Figures 1. to 13. of this application, or any conventional type of. two-prong.

p O rdinarily plug receptacles are utilized either in wall outlet receptacles or at the ends of extension conductor cords to make. a connection with a further conductor cord. However, in so doing, the. utility of such. devices has remained limited since but a single plug can be introduced into any one. plug receptacle, so that but a single cord can be connected thereto. In many situations it is desirable to connect more than. one cord to a given outlet receptacle. as, for example, where a. pair oflamps or a pair of other electrical appliances are. to be connected to such a receptacle for their energization. In the past it. has become customary to use a type of device, sometimes. termed cube. taps whichincludes a single. plug arrangement adapted to be inserted into a wall receptacle; this plug arrangement being connected to a plurality of plug receptacles. formed in the device itself. In this way a plurality of conductor cords can be tapped into the cube tap, to be connected. in parallel and all energized in multiple. upon insertion of. the cube tap. into the wall receptacle. This necessitates the use of separate conductor cords for the. respective electrical devices to be. energized. thereby. The use of such a multiplicity of cords all running to a single point adjacent. the wall. receptacle is oftentimes unsightly and inconvenient. g

The present invention. presents an improved form of plug receptacle. which can be. connected, at. any point along a conductor cord- In. this.

way, it two closely adioining electrical devices element 4| as in Figure 2 is alsapr d or appliances are to be energized r'rem a given single wall receptacle, the conductor cord for one of them. can be plugged directly into the wall receptacle in the usual manner; then by mounting the. plug receptacle of the present invention on. that conductor cord adjacent the second electrical. device, a plug receptacle is provided. into which the conductor cord for such second device would-be plugged, whereby but a single conductor cord extends from the wall receptacle to a point adjacent the two electrical devices being energized. This avoids completely the necessity of using any device such as a cube tap and also eliminates any extra conductor 7 cords running along the floor or wall near the wall receptacle.

The device of Figures 14 to 17' is very similar to" the devices illustrated in Figures 1 to- 13' in its manner of connection to a conductor cord. shown in Figures 14 to 16, this pliig receptacle is. formed by a body member lil, a cover member 82', and a pair of contact members 83 and 84,. these contact members being formed identically. The body member 8! is a generally rectangular" parallelepiped having a cord-receiving channel 86 formed: in the face shown at the bottom of Figures. 14- and 15. A pair of slots 81- and 88? are also formed in the body 8-! extending from the channel perpendicularly thereofand trans versely through. the entire extent of the body member 81. Theseslots 8 and 'allare formed to receive and retain the contacts 86 and" 83'.

The structure of these contacts 83 and 84 is shown in Figure 1.7, which shows a developed view (that is. an. unfolded view) of the contact member. As shown iii-this figure, each contact member is formed of a wider portion 91 and a narrower portion 92. 'Theouter edges of the narrower-portion 9 2 are extended by cuts for a v short. distance along the wider portion at as shown atflii so that when the narrower portion" 92 is bent. at the dotted line 34, it forms the shape shown in: Figure 14, having a pair of upstanding cars 96 left. on the wider portion extending just beyond. the: bend: shown at 91' in Figure 14. These earsv 96: help locate the contact members 83 and 84: in. the slots 81 and 88'; thus, formed in the side wall of each slot 83 and 84 he narrower slot; 98; which is just wide enough to accommodate: the widerv portion. SF of the contact member. Ribs 99 adjoining this narrow slot 88 keep the contact.- member from falling into the large slot 813'- or 84:. However, the separation between the: ribs: Slit is s-ufli'cient to permit free passage of the narrower portion 92 of the contact member, which therefore is locatedwithin the larger-slot 83,. or; as in. a position to be slidably engaged by the pron-gs" of a plug entering the slot 83 or 84.. Thesenarrow slots so extend only partially from the channel 86 toward the upper face 85 of the receptacle body 8 and have a shoulder 97 at their uppermost extent. This shoulder 91' en'- gages the ears 96' and prevents the contact memher from passing out of the slot 83 or as in an upward direction.

- The wider portion 91 of'each contact member also has an extending point Hi2 similar to the poihtsfit shown in. Figures mm 12. This point extends below the: upper boundary of the channel 8.6; and is. adapted topierce: the: insulation of the:- conductor cable and to engaeg one conductor thereof in t esamemanner'asdescribed With respect-toiF-igures. l. to. 10.. A conductor-position.-- ing V-shapecl protuberance: 1.93..- corres-ponding; tor

ovdedi.

V The cover member 82 is formed as a generally open-ended hollow rectangular member with an open upper side as at I116. The cover 82 is adapted to slide over the body member 81, the opening I06 engaging the protruding upper face ID! of the receptacle body to form a smooth outer surface for the fully assembled device. The inner lower surface of the cover 82 carries a pair of protuberances I88 similar in size and location to the protuberances 58 and 59 of Figure 5, which serve to press the conductor cord against the points I02 to make contact electrically between the wires of the cord and the contact elements 83 and 84. It will be noted that since the contact elements 83 and 84 are identical, but are positioned in a back-to-back relationship the points I02 of contact 83 cooperate with one wire of the cord while the points I02 of the contact 84 cooperate with the other conductor as shown in Figure 5.

It will be seen that the configuration of the narrower portion 92 of each contact shown in Figure 14 provides an offset formation. The material of the contact member is brass or the like, having a good degree of resiliency plus good electrical conductivity, and upon insertion of the prongs of a plug into the openings 81 and 88, each prong engages a corresponding narrower portion 92 of the contacts 83 and 84, and the resiliency of the contact members 83 and 84 maintains them under pressure and in good electrical contact with the prongs.

The cover 82 is provided with a partial end wall III which provides a strain relief for the conductor cord by causing the double bend shown at H2 in a manner similar to that described above relative to Figure 1.

It will be seen that this receptacle can be mounted anywhere along the length of a conductor cord. To assemble it on a connector cord, the cover is removed and the cord is laid in the channel 86 with its wires generally overlying the respective sets of points I02. The cover is then passed around the wire (which freely goes through the opening I06 therein) and is slidably engaged on the body 82. In so doing the protuberances H18 press the Wires into good electrical contact with the respective sets of points 102. The conductor cord then may extend outwardly on both sides of the body and in no Way is interfered with by the receptacle.

It will be understood that, if it is desired to place the receptacle at the end of a cord, the end of the cord may be placed in the recess H2 formed in the receptacle body 81 similar to the recess in the plug body of Figure 1 between end wall 33 and partition 3'! as shown in Figure 1.

Accordingly, this plug receptacle may be assembled and mounted or connected to the conductor cord just as readily as the plugs of Figures 1 to 13, requiring no stripping or separation of the wires, or any special attention thereto. The wire is merely laid into the channel 86 and the cover assembled on the body. This simple action provides all the operations necessary for complete assembly, which is thus very easily effected without any tools whatever.

It will be understood that many minor modifications of the present invention can be readily conceived Without departing from the spirit thereof. Accordingly, the above description is intended to be illustrative only, and is not to be interpreted in a limiting sense, the present invention being limited solely as defined in the appended claims.

What is claimed is: I

1. An electrical connector comprising a unitary molded body of insulating material having a pair of parallel contact-element-receiving openings, a pair of sheet metal contact elements positioned respectively within said openings, each of said elements having a contact-making portion adapted to make electrical contact with another electrical element and also having a sharply pointed end opposite thereto, the points of said ends being disposed along parallel lines separated by a distance substantially equal to the separation of the wires of a two-conductor cord intended to be connected to said connector, said body having a straight cord-receiving channel interconnecting the corresponding ends of said openings and extending perpendicularly to said openings and to said contact elements, said element pointed ends extending into said channel adjacent opposite sides thereof, and a cover linearly slidably engageable on and partially surrounding said body, and having an inner surface substantially parallel to said channel, said inner surface also having a pair of protuberances which in the assembled position of said cover on said body respectively overlie the points of respective contact element ends, said protuberances in said assembled position being spaced from said pointed ends by a distance less than the thickness of an insulated conductor of said cord while said cover inner surface is spaced from the opposite boundary of said channel by a distance at least equal to the thickness of said insulated conductor, whereby upon assembly of said cover on said body, friction between said cover and said cord is minimized while said protuberances are adapted to press the respective conductors of said conductor cord against the respective pointed ends of said contact elements to pierce the insulation of said conductors and to make electrical contact with the Wires thereof.

2. An electrical connector as in claim 1 wherein said body is formed with a pair of flanges extending outwardly from and parallel to said channel, and said cover partially surrounds said flanges.

3. An electrical connector as in claim 1 wherein said contact elements and said body are formed with engaging portions which prevent movement of said elements relative to said body in a direction into said openings and away from said channel.

' 4. An electrical connector comprising a unitary molded body of insulating material having a pair of parallel contact-element-receiving openings, apair of contact elements positioned respectively within said openings, each of said elements having a contact-making portion adapted to make electrical contact with another electrical element and also having a sharply pointed end opposite thereto, said body having means defining a conductor-cord-receiving channel interconnecting said openings and extending perpendicularly to said contact elements, said contact element pointed ends being located at respectively opposite sides of said channel, and a generally channel-shaped cover linearly slidably engageable on and partially surrounding said body, said cover having a partial end wall which in the assembled position of said cover extends across said cordreceiving-channel for providing a strain relief for said conductor cord, the inner surface of said coverbeing substantially parallel to said channel and having a pair of smoothly tapered protuberances' which in the assembled position of said cover on said body respectively overlie the pointed ends of said contact elements and are spaced from said pointed ends by a distance less than the thickness of the insulated conductor of said cord, whereby upon sliding assembly of said cover on said body said protuberances are adapted to press the respective conductors of said conductor cord against the respective pointed ends of said contact elements to pierce the insulation of said conductors and. to make electrical contact with wires thereof.

5. An electrical connector as in claim 4, wherein said body has a further recess adjacent one end thereof and parallel to said contact-elementreceiving openings for receiving the end of said conductor cord.

CHARLES E. GILBERT.

References Cited in the file of this patent UNITED STATES PATENTS Number 5 1,966,563 2,159,064 2,353,778 2,360,444 2,402,766 10 2,419,652 2,475,243

Number Name Date Russell July 17, 1934 Walter May 23, 1939 Mattis July 18, 1944 Pollock Oct. 17, 1944 Moore June 25, 1946 McLarn Apr. 29, 1947 Irrgang July 5, 1949 FOREIGN PATENTS Country Date Great Britain Apr. 6, 1933

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