US2954544A - Electrical plug connectors - Google Patents

Description

Sept. 27, 1960 J. w. FOCOSI ELECTRICAL PLUG CONNECTORS Filed July 22, 1957 m 2 M M w 0 5 v w M 5 0 a R 4 6 2 6 M, 3 3 2 Wu %fiw F M/Vf/VTOI?! JOSE/ H l l/ FOCUS/ ATT'Y 2,954,544 ELECTRICAL PLUG CoNNEcToRs Joseph W. Focosi, 5119 N. Nagle Ave., Chicago 36, '11]. Filed July 22, 1957, Ser. No. 673,256 1 Claim. 01. 339- 182) This invention relates in general to an automotive accessory plug and is more particularly described as an electrical plug connector adapted to make electrical connection with an electric outlet socket now usually installed on automobile panel boards for use with cigarette lighting and electrical equipment, but which may have a more general application with any electric lighting socket.

The electric socket now commonly installed upon the front panel board of an automobile and sometimes in other accessible places may now be used for connecting and illuminating automobile safety flares and signals, heating baby bottles, operating electric shavers and other similar uses as well as for the installed cigarette lighters.

In the present application, a quick acting accessory plug is provided which may be inserted or slipped readily in place which will tightly engage the center and a side contact of the socket by simply sliding the plug into position, and at the same time providing an outer handle for inserting and removing the plug.

An important object of the invention is to provide an accessory plug in which both contacts are spring pressed so that the plug may be pushed or slipped into engagement with a sliding movement instead of a rotary movement;

A further object of the invention is to provide an accessory plug having a portion serving as a handle for inserting and removing the plug from its connection with a. socket; to provide improved means for connecting the contact elements of the plug with wire conductor terminals; to provide improved means for attaching contact members at the ends of conductor wires; to provide improved means for producing and attaching conductors to the ends of conductor wires; to provide improved terminals for self-locking engagement; and to provide a construction for reversing polarity when desired.

Other objects of the invention will be apparent from the accompanying drawings, in which,

Fig. 1 is a perspective view of an accessory plug in accordance with this invention;

Fig. 2 is an enlarged split view of an accessory plug casing as shown in Fig. 1, showing the conductors within the plug and the conductor wire attachments thereto as the plug is applied in a socket;

Fig. 3 is a fragmentary view of an improved conductor fastening; Fig. 4 is a perspective view of a modi fied conductor terminal; Fig. 5 is a perspective view of conductor terminal with a straight tip;

Fig. 6 is a perspective view of a portion of a strip of conductor contacts; and Fig. 7 is a perspective view showing the contacts of Fig. 6 as applied to the ends of conductor wires.

This accessory plug is made of complementary halves with conductors assembled in one part and the two parts then riveted or otherwise tightly connected together with provisions for securely attaching contact at the ends of the conductors inserted through openings at the end of latent O i Patented Sept. 27, 1960 the casing. The contacts are attached to the ends of the conductors before they are inserted in the casing.

Referring now more particularly to the drawings, this plug connector comprises two similar casing parts 10 and 12 which when placed together have a longitudinal split forming a circular contact portion at one end and a somewhat flattened handle portion at the other end and the longitudinal split is on a substantially diametric central plane for assembling the parts in the casing. These casing parts 10 and '12 are of hard plastic or other other suitable non-conductors and are substantially hollow at the inside except for certain connecting operating parts. In one end of each casing part is a semi-circular recess 14 for seating a circular contact tip 16 therein, the easing part having a cross partition 18 spaced a short distance within this end and also having a recess 20 therein for seating the tip. At the inner end of the tip is a flange 22 which bears against the inner side of the partition 18 and is held in resilient engagement therewith by a bent spring contact 24 firmly attached at one end to the inner end of the tip. The outer end of the tip 16 is rounded to make a good electrical engagement.

At one edge of the casing 10 is an inwardly recessed flat portion 26 having slots 28 and 30 at the ends and inwardly extending projections 32 and 34 at the ends of the flat portion 26. This provides an inwardly opening recess 36 into which a sharp angular bend 38 of the spring contact 24 and is movable freely back and forth therein. The other end of this contact 24 has an angul'arly bent extremity 40 hooked around a post 42 formed in the handle end of the casing. The spring contact 24 being made of metal, resiliently presses the flange 22 of the tip 16 against the partition 18 and any depression of the tip causes the angular bend 38 to move freely backward in the recess 36.

Another bent spring metal contact 44 has an angularly offset portion 46 which projects outwardly through the slot 30 on the outside of the flat portion 26 and inwardly through the slot 28 with one bent end 48 disposed within the casing and engaging the inner side thereof adjacent the cross partition 18. The other end of this spring contact 44 is hooked around a post 50 and has an angul'arly bent extremity 52 extending inwardly from the post. The flat portion 26 and the projections 32 and 34 provide means for spacing the metal contacts 24 and 44 apart and also eliminate arcing of the current between them.

Between the posts 42 and 50 is a longitudinal partition 54 with a connected cross piece 56 at the inner end, the partition 54 and the posts 42 and 50 being of a length to extend above the split line between the casing parts and to extend into corresponding recesses (not shown) in the casing part 12. Also at the other end of the plug are two projections 58 which register with recesses (not shown) in the other casing part 12, these projections and the partition serving to register and position the casing parts in alignment. In order to secure the casing parts with the spring contacts therein tightly together, a screw or rivet 60 is inserted through registering perforations in bosses 62 located centrally of the casing parts and the ends of the rivets or the other fastening means are seated in the recesses 64 in the outer sides of the casing parts.

In order to prevent the spring contacts 24 and 44 from moving away from their respective posts 42 and 50, ribs 66 and 68 are provided near the handle end of the plug connector which extend up close to the respective posts 42 and 50, but are separated from the posts by slots 70 and 72 respectively into which the edges of the spring contacts 24 and 44 are seated, the angular bent extremities 40 and 52 hearing resiliently but against the intermediate partition 54 which separate them when there are I no conductors attached to the plug.

In order to connect a pair of conductors 74 and 76 of the twin connected type and preferably having stranded copper wires 78 in the plug, each conductor has a terminal:80 (FigsLZ and, 7) i with portions 82 wrapped aroundv the extremity of the wire insulation ofthe conductor and teeth ,84 formed up of the material between the wrapping portions 82. so that when these portions are crimpedupon the insulated end of the conductor, they will penetrate the wrapping and willengage-the stranded wires 78-:makinga: satisfactory electrical connection therewith. Theouter end. of each terminal 80 has a hat portion 86 withan angularly bent extremity 88.

In'Fig. 4, a terminal 81 is shown having teeth 83 at the sides bendable over the insulation 74 of a conductor and havingsmaller teeth 85 at the sides bendable over stripped metal wires at'the end of the conductor. A portion: 87 ,is curved'instead of fiat and an extremity 89 is bent angularly to-the adjacent curved portion 37. This cont-act makes a firm engagement with the bent extremities 49' and 52 of the spring contacts when inserted in the endiof a plug.

Inapplying these terminals 80 (and 81) to a pair of connected conductor wires, the fiat portions 86 are at the insides andthe bent extremities 88 extend outwardly so that when these conductors are to be connected into the'plug, the terminals 80 are inserted in the handle end of the plug at opposite sides of the partition 54 and are pushedinwardly against the bent extremities 40 and 52 of the spring. contacts 24 and 44 respectively as shown more clearly inFig. 2 so that these bent extremities extend over the ends of thebent extremities 4d and 52 and are pressed by them tightly against the partition 54 holding the terminals and conductors attached thereto tightly in placeand in good electrical contact.

The terminal 80 as shown in Fig. 5 is made up of a fiat extremity 86 and the wrapping portion 82 which is applied to a conductor is shown with the teeth 84 indented inwardly. The outer flat portion 86 may be formed without the outer bent extremity 38 and if inserted in a plug in such condition, the terminals attached to conductors are held by the resilient engagement of the bent extremities 40 and 52 but conductors with the bent ends 88 and .89 are held much more firmly in position.

In order to provide terminals which are tightly lodged in place and also make improved contact engagement, terminals 99 and 81 as shown in Figs. 3 and 4, the contact portions of which are formed with curves 87 or angular waves 92 and 94 adapted to seat the bent extremities 40 and 52 of the spring contacts 24 and 44 between the waves of each terminal, making firm electrical connection with the spring contacts.

In all forms of terminals 89, 8d and 92 as shown by Figs. 2, 3 and 4, the inserted extremities of these terminals engage the connected cross piece 56 and prevent or limit the insertion of the terminal contacts beyond the cross piece, the engagernentof the bent extremities prevent withdrawal of the terminals.

At the end of the plug opposite the contact 16, it is formed with opposite inwardly rounded grooved portions 9'6 and with opposite flattened sides 93 at rig-ht angles thereto so thatthe plug may-be tightly gripped and-insertedin close quarters and forming: forefinger and thumb engaging portions. The flattened portion of the handle is marked with plus) indicating the polarity of the contact tipconnection, and -(minus) indicatingthe polarity of the offset projection portion 46. The plug 16 when inserted in-a socket 100 will alwayscause engagernent of the plug with a central contact 102 in the end of the socket and the offset portion 36 will always engage a wall portion 104--in the outer portion of a socket or receptacle. In making this engagement, it is not necessary to ,turn. the plug into. the socket, but spring contact 44 to which the offset,46 is connected has sufi'icient resilience so that it will beheld firmly but removably in the shell and the contact tip'resilient-ly engaged with the Gentral contact 102. In removing the plug, it is pulled straight out, the olfset portion 46 yielding or springing inwardly as the plug is removed.

Some automobiles are now equipped with 12 volt batteries and some still have 6 volt batteries. The lighter receptacle socket 1% for a standard 12 volt battery is smaller (by .028 of an inch) than a standard 6 volt socket, and a 6 volt accessoryplug is provided with a round protrusion 101 which. projects, approximately .025 ofwaninch outwardly from the plug, at the forward end of its thickest midsection'portion; Nearthe handle end is a circle RPS-with the designation 61 therein, The 12 volt plug is similarly marked 12v in the circle 103, and the universal plugwithno protrusionhas no marking.

In producing the contact terminals for the conductors, they may be stamped from a continuous strip 106 of material having ears 108 and formed with locating or positioning openings 110 at-spaced distances apart. The tongues84 are punched out of the material between the ea-rsv1'08 and they may be offset oppositely at the same timeif desired to form the opposite portions 82 which are bent about the-conductors. ably formed between the side portions 82 and the fiat portion 86 and the bent extremity 88 is preferably formed when the last terminal is cut from the strip. The tenninal forming operation is thus continuous and is usually performed on an automatic machine, preparing the terminals for separate application to the ends of insulated conductors .as shown. The terminals 31 having the teeth 83 and are similarly produced.

Accessory plugs of this kind are thus prepared completely without any soldered connections; a firm electrical connection is made between conductors which are attached thereto; the terminals may be used for trouble lights, portable spotlights, bottle warmers, battery chargers, defrosters, electric fans and many other electrical automobile accessories. The plugs may also be used with other outlet sockets for making similar electrical connections for other electrical accessories. The terminals may be furnished separately in connection with conductors having connected terminals as shown, and they may also be furnished with terminals which are. applied to other conductors connected to the desired accessories.

While a preferred construction has been described in some detail, it should be regarded byway of illustration and examples rather than as a restriction or limitation thereof, as many changes in the construction, combination and arrangement of the parts maybe made Without departing from the spirit and scope of the invention.

I' claim: Anelectrical accessory plug 'for a socket having an inner end contact and a shell insulated therefrom, comprisinga longitudinally split hollow insulating casing, a pair of spring strip contacts-mounted in the casing having bent portions and adapted to flex therein, means in the casing engaging one end of each contact to, holdthem firmly and in spaced relation, one contact having a slidable, tip at the other end of the contact projecting from the end of the-casing to resiliently engage the inner end contact of a socket, the other strip contact having-an angular offset near its other end projecting laterally from and depressible in the casing tomake 'a resilient connection with. the shell of the socket, means to contact the said engaged ends of the contacts in the casing and extending therefrom to provide electric circuit connections, said slidable tip having a flange at a distance from the end and inside of the casing, and the casinghaving a perforated cross partition through which the tip extends and the flange engages the inner sideof theipar-tition to limit the outward sliding movement of thetip pressed outwardly by the bent portion of the resilient strip Contact, the hollow interior portion of the casing providing a space to receive the bent portion transversely thereof, the interior of the casing havlng a fiat Notches 112 are prefers 5 portion adjacent the angular offset of said strip for spacing the strip contacts apart and inward projections at the ends of the flat casing portion forming an inwardly opening recess to receive the extremity of said bent portion to guide and limit the movements of said strip contact and the tip as it is moved back and forth.

References Cited in the file of this patent UNITED STATES PATENTS 1,949,141 Blaylock Feb. 27, 1934 2,238,696 Hanley Apr. 15, 1941 2,245,986 Krauss June 17, 1941 David July 10, 1945 Bellek Feb. 28, 1950 Stanley Aug. 7, 1951 Knapp et a1. Mar. 24, 1953 Berg Aug. 4, 1953 Felts et al. Sept. 8, 1953 Ziemianin Oct. 27, 1953 Hurlbut Apr. 6, 1954 Bird et a1 Apr. 17, 1956 Morschel Feb. 8, 1957 FOREIGN PATENTS France May 3, 1943

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