US2260365A

US2260365A - Electrical plug connector

Info

Publication number: US2260365A
Application number: US196632A
Authority: US
Inventors: Charmoy Harry
Original assignee: Hatfield Wire & Cable Co
Current assignee: Hatfield Wire & Cable Co
Priority date: 1938-03-18
Filing date: 1938-03-18
Publication date: 1941-10-28
Anticipated expiration: 1958-10-28

Description

H. CHARMOY ELECTRICAL PLUG CONNECTOR Filed March 18, 1938 2 Sheets- 821a l INVENTOR Harry Oharmqy ATTORNEYS H. CHARMOY ELECTRICAL PLUG CONNECTOR Oct. 28, 1941.v

I v 2 Sheets-Sheet 2 v Q I Filed March 18; 1 958 INVENTOR arry Uiax'mqy BY I @0544 c aw ATTORNEYS Patented Oct. 28, 1941 su-zomcar. rwo. oomcroa Harry Charmoy, Long'lsland City, N. Y., to Hatfield Wire & Cable 00., Hillside.

assignor N. 1., a

corporation of New Jersey Application March 18, 1938, Serial No. 196,832

210laims.

The present invention relates to electrical plug connectors, and as far as certain features are concerned, to connectors of the prong type, in which the root sections of a pair of spaced terminal pieces are retained in corresponding preformed longitudinal recesses of a one-piece premolded resilient plug body.

Also, as far as certain features are concerned, the invention is adapted for that type of electrical plug connector, which is assembled by drawing the terminal pieces with the conductor wires electrically attached thereto, through the respective recesses; of the plug body from the neck end oi said body, until the prong sections of said pieces extend outwardly beyond the face end of said body, and the roots of said pieces are embedded in said recesses.

One object of the invention is to provide an electrical plug connector of the type referred to, in which terminal pieces are accurately positioned longitudinal and firmly retained in the recesses of the resilient plug body, without the use of screws, rivets or other similar fastening means.

Another object is to provide a male plug connector having terminal pieces with spring rongs,

which retain their resiliency under the most severe conditions of use, which, when inserted in a socket plug, will be firmly retained in electrical contact therewith, and which can be withdrawn therefrom without catching in said socket plug. Y

Another object is to provide terminal pieces, having spring prong fingers affording the greatest amount of resiliency, while presenting the maximum amount oi contact area, so that said fingers will yield readily into effective electricalcontact with the terminals of a socket plug, with a minimum amount of distortion of said terminals.

In carrying out the invention, each terminal piece is made from a single fiat strip of metal, rcversely bent at opposite ends to form a spring contact finger at the prong section, and to aflord at the root section the double thickness required to completely fill the corresponding recess in the plug body, alter said prong section with its double thickness has passed through said recess during assembly process.

As another feature, the terminal piece in certain embodiments of the invention, has a reversely bent prong section, with a spring portion, which extends longitudinally of, and transversely symmetrically with respect to said section, and which is free to flex longitudinally when inserted in a socket plug, the unsprung portion of said section having anchoring means with respect to the resilient plug body.

As another feature, the terminal piece of certain embodiments oi the invention has a reversely bent prong section, divided longitudinally to form at least two spring fingers, independently yieldable into electrical contact with the terminals of a socket plug.

In the accompanying drawings, in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. 1 is a perspective view of one form of assembled plug connector, embodying the present invention,

Fig. 2 is a longitudinal cross-section of the assembled plug connector of Fig. 1,

Fig. 3 is a front elevation of one of the terminal pieces of the plug connector of Fig. 1,

Fig. 4 is a longitudinal section of the terminal piece, taken on line H of Fig. 3,

Fig. 5 is a rear elevation of the terminal piece of Figs. 3 and 4.

Fig. 6 is a side elevation, partly in section, showing the first stage in the mounting of the terminal pieces of Figs. 3 to 5 in the plug body,

Fig. 7 is a longitudinal section of a portion of the plug body, with another form of terminal piece mounted therein,

Fig. 8 is a perspective view of the terminal piece 01' Fig. 7, showing one of its spring fingers partly broken or! for thev sake of cleamess,

Fig. 9 is a longitudinal section of a portion of the plug body, with another form of terminal piece mounted therein,

Fig. 10 is a perspective view of the terminal piece of Fig. 9, showing one of the spring fingers partly broken on,

Fig. 11 is a longitudinal section of a portion of the plug body, with another form of terminal piece mounted therein,

Fig. 12 is a perspective view of the terminal piece of Fig. 11, showing one of its prong sections partly broken ofl,

Fig. 13 is a longitudinal section of a portion of the plug body, with still another form of terminal piece mounted therein, and

Fig. 14 is a perspective view of the terminal piece of Fig. 13, and showing one of its spring fingers partly broken oil.

Referring now to the drawings, there is shown in Fig. 1 an electrical connector plug, including a premolded one-piece flexible insulating body It, desirably made of soft rubber composition, a pair of transversely spaced terminal pieces ii, firmly ing the root sections ll of the terminal pieces II, I

and interspaced by a central plug body section l9, and a pair of recesses 20 diverging from said center recess l6, and communicating with the inner ends of said recesses II respectively. The body section l9 has a pair of inclined surfaces 2| at its inner ends, serving to form seats for offset portions of the terminal pieces I I as will be more fully described hereinafter, and the diverging recesses 20 are provided with bays 22 on their outer sides for receiving the enlargements formed by the terminal connections between the bare ends 23 of the conductor cord l4 and the inner terminal ends of said pieces.

In the form shown in Figs. 1-6, each of the terminal pieces H is made from a single flat strip of resilient metal such as brass, main backing section 24, reversely bent sharply at 26 to form a prong spring finger 2'5, and a section 21 at its other end reversely bent sharply at 28 in close overlapping relationship with said backing section, and forming therewith the root l8 of double thickness adapted to be embedded in the corresponding recess ll of the plug body I. The spring finger 25 has its free end spaced from the backing section 24, and is desirably slightly bowed outwardly lengthwise thereof, so that said free end will not catch in the contact socket of a socket plug (not shown) when said spring finger is being pulled out therefrom.

The backing section 24 and the spring finger 25 are desirably provided with registering holes 29 near the fold line 26, for receiving a pair of hook members 4| in the operation of mounting the terminal piece in the plug body as shown in Fig. 6, and as will be hereinafter more fully described.

The terminal stripis sharply crimped at the bent section 28 to form an oblique offset 30, which is adapted to seat on the corresponding inclined surface 2| of the plug body I0, and which is desirably provided with a notch 3| in the center thereof for receiving the bare end 23 of one corresponding conductor wire in the formation of the electrical connection between said wire and the terminal piece II. This notch 3| is desirably formed by punching a hole through the terminal strip prior to the bending and crimping thereof, and reversely'bending said strip across the center of said hole along the fold line 28. This hole serves not only to form the notch 3|, but also serves to weaken the strip along the fold line 28 so that it may be easily bent along said line.

In the formation of the electrical connection between a wire and the terminal piece H, the bare end 23 of said wire also passes desirably through registering holes 32 formed in the backing section 24 and-the overlapping section 21 of said terminal piece.

The bent-over section 21 has a substantially triangular tongue 33 struck therefrom to form a barb directed toward the root end of the terminal piece and serving to engage the plug body I0, so

l6, extending through the neck l and includes 9.

as to accurately locate the terminal piece I longitudinally of said plug body as will be more fully described hereinafter.

The

free ends

34 and 35 of the

bent terminal sections

25 and 21 respectively are a comparatively short distance apart and the backing section 24 is provided with an embossing 36 extending longitudinallyv across the space between said ends to impart substantial rigidity to said backing section where the terminal piece is of single thickness.

In the operation of mounting the terminal pieces into the plug body, the end of the conductor cord I4 is split to form a pair of branch connectors 40, and the outer bare ends 23 thereof are passed through the notches 3| and through the registering openings 32 of the terminal pieces I and desirably soldered therein to form strong electrical connections therewith. The two terminal pieces H as shown in Fig. 6 with the wires electrically connected thereto and the spring fingers 25 facing each other, are positioned on the neck side of the clamped plug body In preliminary to the assembly operation. A pair of spaced fingers 4| having hooks then forced respective through the recesses ll, 20 and then through thecenter recess |6 of the plug body l0 from the face end l3 thereof, until said hooks extend outwardly beyond the neck of said plug body.

In the molding of plug body In, thin walls 43 are formed between the mold coresdividing the V recesses 20 and the center recess l6. These thin walls 43 are ruptured when the hooked fingers 4| are forced therethrough, and for the purpose of clearness are shown in Fig. 6, but not in Fig. 2. After the hook fingers 4| are passed through the plug body I!) as shown in Fig. 6 the hook ends 42 thereof are slipped through the registering openings 29 of the terminal pieces These 'hook fingers 4| are then retracted through the plug body, carrying with them the terminal pieces these fingers 4| being given the necessary lateral movement corresponding to the sinuous shapes of the various recesses of the plug body as they pass therethrough, until the root sections|8 of said terminal pieces are properly positioned in the recesses respectively with their offset sections 30 seated upon the inclined surfaces 2| of said plug body. In this mounted position of the terminal pieces H, the backing sections 24 of the respective terminal pieces II will be parallel to each other, the spring fingers 25 will face each other, and the free ends of said fingers will extend a. small distance beyond the face end |3 of the plug body I0, so that said fingers will not bind on said face end, and will be free to flex when inserted in a socket plug ,(not shown)- nal pieces into the interior of said body l0, thereby assuring against the binding of the spring fingers on the face end |3 of said body. When the terminal pieces H are brought home in their proper position indicated, the hook fingers 4| are disengaged from the terminal piece The cross-section of each recess ll of the plug body I0 is such that the root section l8 of the corresponding terminal piece M will be frictionally gripped firmly therein by the resilient material of the plug body. Since this recess I! must be large enough to permit the passage therethrough of the double thickness of the prong section |2 of the terminal piece during at their outer ends are The tongues 33 by their engagement with the plug body In serve to prevent the retraction of the termiaeedaes the assembling operation, which double thickness is no greater than that'of the root section IS, the double thickness at said root section will assure the complete filling of said recess so-that said terminal piece will be held firmly in position. The double thicknessat' this root section serves not only to'completely fill the recess 11,

'but'also serves to impart substantial rigidity to the onset 30, which by its seating engagement with the body seat 2| will eflectively-resist"themost severe pulling stress on the terminalpiece V encountered during use. The embossing 36 'on the backingsection 24, extending from opposite sides of the body face I3, serves t'o strengthen said backing section against transverse bending, especially at said body facewhere said bend ing would otherwise be apt totake'p'lace.

As far as certain aspects of the invention are 1 concerned the prong section I! of the terminal piece Il may be made withoutthe spring finger 25, so that said section will be of -a"'single'-t hickness. In that case the recess II will permit'the easy passage of this 'pr'ong section therethroug h during the assembling operation, but WiIl be completely filled by the double thickness 01 the root section in assembled position.

In the forms shown in Figs. 7- to 14, ther'e and transversely symmetrically with respect to said section, and which is freeto flex longitudinally, when inserted'ina socket plug/the unsprung portion of said section having anchoring means with respect to the -resilient"plug body" In common with the terminal piece shown is provided a reversely bent prong section, with a spring portion, which extends longitudinally of in said recess, withthe barb'56 biting into the plug body section l9 to prevent the retraction of the terminal 'piece into the interior of the plug body. This central prong member '55 also. serves to bring the contact area of the terminal piece-to that required by the Board of Underwriters, and to form with the backing section 24a,- a-doublu thickness at the face end I3 of the mug body;

affording the necessary strength against .transverse bending without the necessity 'OffEmDOS S- I ing said backing section.

Since the two spring fingers56 arerelatively: yieldable transversely, the prong will more read-'1 ily 'yield into efiective electricalcontactywith l5 the corresponding terminal member of asocket plug, so that permanent" distortion of said terminal-member by said contact'is obviated.

, its inner unattached end in'an oblique barb,

corresponding to that shown .inLFig; 8, 'and'the two side. members 64 are" longitudinally bowed in Figs. 1 to 6, the-terminal piece shown in Figs. 7 and 8 is made from a single flat strip of resilient metal, and has a main backing section 24a, and areversely bent section Zla at one end, forming'with said backing sectionf-a'root I6a, provided with an end oblique offset 3M for seating engagement inthe plug body, and

open ings

31a and 32a for receiving the bare'en'ds' of a conductor wire.

The modified form of prong includes a'section 50, reversely bent sharply-from the outer end of the main backing section 241a, and'having an outer end portion 5|, of substantially length in contact with said backing section, to facilitate entry of the p'rong into a socket plug. The inner end portion of the prong section 50, is divided longitudinally to its unattached end desirably by a pair of parallel slits 54, to form a central straight flat member 55, and a"-pair of side members'56 of equal length. These side members 56 are-bent obliquely outward from the backing section 24a to form substantially straight relatively yieldable spring contact Tflnge'rs, and the central prong member 55 is in contact with the backing section 24a, and desirably formed at its unattached end with an oblique barb 58, beyond the free ends of the spring fingers 56.

The two prong sections 240. and 5| are provided with registering holes 29a for engagement by the pulling hooks 42 shown in Fig. 6, during the assembling operation.

In the plug assembled position shownin Fig. 7, the root 16a of the terminal piece is retained in the corresponding. recess ll of the plug body ID as already described with reference to the construction of Figs. 1 to 6, the free ends of the spring fingers 56 extend a small distance beyond the face end l3 of the plug body topermit ready transverse fiexure of said fingers, and the inner end of the central prong member 55 is anchored outwardly along the main lengths thereof to form relatively yieldable spring fingers, with inner unattached ends .66 extending substantially parallelfto and in contact'with the backing section"24b.- v i f :In the plug assembled position shownin Fig;

9, the root l8b of the terminal piece is held in its respectiveplug recess H, the prong extends beyond the face end- B ofithe plug body l0, and

the offset end of the central prong member 63, as well as the" ends 66 of the springfingers 64 are retained insaid recess. By means'of this construction, the spring fingers 64, with their inner ends 66 held against transverse movement, butfree to slide longitudinally in the recess ll, will flex longitudinally. into'electrical engagementwiththe contact blade of a socket plug, by=a snap actibnwhen inserted therein,

and the possibility of thesespring ends 6lircatch- I I ing in,the plug socket, when the terminal piece is being pulledout therefrom is'obviated. Furthermore, thereis no possibility that thesefin'gers will lose their resiliency, or thatthey 'will be bent permanently into ineffective positionnlose tothe backing section 2422 after a period of use. In the form shown in Figs. 11 and'12, the terminal piece has a root I80, identical with'that shown in the construction of Figs. 7 and8, and theprong is formed with a reversely bent section 10,,longitudinally divided to its unattached inner end, desirablycby a' pair of parallel slits -'ll, to form a pairof similar straight side meme bers l2, and a central member 13. Thisicentral member 13- is bowed outwardly to form a spring finger, and terminates at, its inner end me section H, parallel to and in contact with the,

15 of the side members 12, are anchored. inv said I I recess against lateral movement-with respectto x the backingsection 24c so that the terminal piece a since 'the:unattachedend 'll thereo'fcan slide, ,7 e I a Jnain backing section, .a section at one end "forming, therewith a rootof doublethicknessfor frictional] engagement in such recess, 'a' section I 1 at g-the [other end} revers'ely bent-with vrespect'l. the e if r ns a s fi g r j he free,

spri'ng fingers 80, instead, of extending obliquely straight along .their; entire lengths from there- 1 ver'sely ibent prong,section-jhxhave respective the backing sectionfld, and respectiveportlons blades of .;said'socket. :All of .theiconstructi "14 are desirably assembled iii-Pa v manneri indicatedwith reference to theconstructionofFigs.

above description or shown in the accompanying drawings/shall be, interpreted-as illustrative and-f notin a limiting'senset l claimj-ias-ic new and, desire to secure by Letters resilient plug body,'and' comprising a strip-like memberhaving a mainbacking section; 'a section plug body' toform a contactlprong, the free ends" of-said'reverse1y bent sections-extending to near rpre formed recess of r a one piec'e pre molded tion at one end thereof reversely-bent topro'vide springiingeriand the opposed portion of said thefaceend ofsuch plug body to form a conis held: against retraction in the a plug body, and

I the-.-spring flngerpll has a-sn ap,actionwhen inserted in. a plug socket," and will notcatch in v5 said socket whens withdrawn; -,therefrom. This gspringiqilnger :13: is free Alex longitudinallm;

longitudinally inthe recess IL- "I'he' iconstructiono'f Figs: ,13, I and 4 is v to that shown in Figs. '1 and 8, exceptthat the portions 82, 'extendinglobliquely with respect to 83: extending substantially 1 parallel -,,thereto.; This construction may be desirable for;,use,with"" i certain typesrof :socket plugs, since :thefspringi angers i" I will T bejsubstantially parallel tojthe. plug ssocket; whensinserted therein, thereby as silrings greater contactflsarea with the contactj as: teachings. :1 "to 1=.to 6,?and. as far as certain'aspects of theuin ve'ntion embodied in these constructions'of (Figs. If-to "14 areconcemed, the roots of the terminal "pieces may be'madeof-a single thickness.

. 30 m'an'yx changes could be made inthe above; i. article and :many apparently widely different a embodiments :of this invention could be made withoutvdepartingfrom the scope of the claims, it is intended that all matter I containediin the ig-Having jthus-described.my invention whati' l 7 at one'end thereof reversely bent to provide with said backing sectiona double my root having} a bent double ply end for anchoring'eng'agement in such recess, and a-se'ction at the other end 50 of' 'said backingpsectionreverselybent to form'a 'springiflnger extendingalong the {length-of saidv backing-section, said spring finger 'and the opposed portion of said backing section being adapted ,to'extend beyond the face end of such "with said backingsection a root of-double thick Y jnessfor frictional engagementins'aid recess, and

-'a section at the other end of ,such backingsection reversely bent to form'a spring-finger, said T backing section being'adaptedto extend'beyond "tact prong, the free ends of said reversely bent sections being spaced; apart, and the portion of said backing section between 1 the free, ends j 'of 75 "gaeo, gsaidlreversely jbent sections being provided. with I.against,transverse' bending;, facture, an electrical;

a longitudinal'embossing to'strengthen the p rg; tionof said terminal piece-of single .3. As an article of man terminal piece, adapted to, be fembedded infa. pre-formed recess of a one-piece v resiliefnt plug body and comprising a. strip-like'member having thereof reversely bent'f with respect thereto and ends of said' reverselvbent sectiqnsbelng spaced. I apart', the portion of said backingfsection be-i tween saidfree ends being provided with an eme bo sing extendinglengthwisefof's'aid backingsec ti ijrb mpsnin rigidity to team backing s j type, including a one-piece resilientzplug body having'qa central recess entending throughthe neck end thereof), and agpair-iof spaced parallel recesses-communicating withflsaid central recess, f 7 a-pair.. of terininal pieces each havingamainf;

transversely-Hunt to provide with said/{backing section aj ro' c t of double-thicknessv frictionally re ftained in jone of said spaced recessea anda sec 35 reversely bentto' [form a spring finger, each of a said spring fingers and the; opposed portion of th o o n back n e e xt n n 9 i: j wardlyyondthe face end 'of said plug body;

tion' at the other end of said flbacking section t0.,formj a contact prong, the-free ends of said reversely-;.bent sectlonsbeing spaced apart, and Y the portion of said backing vsectionbetv reen said 1 free-endsbeing providedflwith alongitudinally; x extending embossing to strengthen said backing 'section against transverse bending; and a con d'uctor jcord extending through said central; re

cess {and presenting bare wires 'atdts ends, elec-f trically ;connected ,to the inner ends ofgth re-x spective terminal pieces.

: s an electrical plug connector of the brbii j having a central recess throughtheneck'end thereof, a pair of substantially. parallel spaced "type, including a one piece resilient plug body, f

elongated-passageways extending tov the face end l i of said plugbody,, and a pair ofspaced, recesses diverging from saidcentral recessandgcommuni 1 K eating withthe respectivei inner ends of-said l parallel passageways, said passageways defining therebetweena plug section aflording; a.

pai of'spaced inclined surfaces at itsinner end ad acent to therespectiv'e inner ends-of said pas I sageways, a pair of terminal pieces: having doubled over root sections at their inner ends frictionally retained, in the respective passage- .ways, and having double. plyintui nedoif sets at. i

said inner ends Seated ;11PQIl;S8i1d inclined Sur faces, and prongs at theirouter ends extending outwardly beyond'the faceend'of said plug body, and iaconductor cord extending through: said' central recess, and having a pairof diverging branches in, the respective div rging recesses,

- ,presentingbare wires :at their ends, electrically respectiveconnected to, the Iin'nerends ofthe terminal pieces. y

I -6. An. electrical plug connector: of the prong type, including a one-piece resilient plug body having a' central-recess through the neck end thereof, a pair of substantially parallel spaced elongated passageways extending to the face end of said plug body, and a pair-of spaced recesses diverging from said central recess, and communicating with the respective inner ends of said passageways, said recesses having laterally outwardly extending bays on the respective outer sides thereof, a pair of terminal pieces having doubled root sections at their inner ends with the inner extremities thereof turned inward to form'double ply offsets anchored in said diverging recesses, the lengths of said root section being frictionally retained in their respective parallel passageways, and prongs at their outer ends extending outwardly beyond the face end of said plug body, and a conductor cord extendin through said central recesses, and having branch sections in said diverging recesses, presenting bare wires at their respective ends, with electrical connections to the inner ends of the respective terminal pieces, the enlargements formed by said electrical connections extending in the re- 7 spective bays of said diverging recesses.

7. An electrical plug connector of the prong type, including a one piece resilient plug body, having a central recess through the neck end thereof, a pair of substantially parallel spaced elongated passageways communicating with said central recess, and a pair of recesses diverging from said central recess and toward the respective inner ends of said passageways, thin webs extending across the respective recesses, a pair of terminal pieces having root sections frictionally retained in the respective passageways and prongs at the outer ends thereof extending outwardly beyond the face end of said plug body, a conductor cord extending through said central recess and having branch connections passing through said diverging recesses, extending through and engaged by said webs, and electrically connected at the inner ends thereof to the respective terminal pieces.

8. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member, having a main backing section, and a prong section at one end, reversely bent, and slit longitudinally to form a pair of relatively yieldable spring fingers said fingers being bowed for resiliency.

9. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member having a main backing section, and a prong section at one end, reversely bent, having parallel slits extending longitudinally to the unattached end of the prong section, the metal between a pair of said slits being bowed outwardly solely at the median part of its length.

10. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member, having a main backing section, and a prong section at one end reversely bent, and divided longitudinally to its unattached end to form a pair of adjoining members, one of said 'niembers being in close lapping proximity to said backing section throughout substantially the entire length of said member, and having its inner piece adapted to be retained in a resilient plug body, and comprising a strip-like member, having a main backing section, and a prong section at one end reversely bent and divided longitudinally to its unattached end to form a pair of adjoining members, one of said members having an outwardly bent portion to form a spring finger, and one of said members having at its inner unattached end an offset, adapted to be retained in said plug body in assembled position, and to prevent the retraction of said terminal piece into the interior of said plug body.

12. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member, having a main backing section, and a prong section at one end reversely bent and divided longitudinally to its unattached end to form a pair of adjoining members, one of said members, having an outwardly bent portion to form a spring finger, the other member being substantially flat and in contact with said backing section, and having at its outer unattached end an offset, adapted to be retained in said plug body in assembled position, and to prevent the retraction of said terminal piece into the interior of said plug body.

13. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member, having a main backing section, and a prong section at one end reversely bent, and divided longitudinally to its unattached end to form three adjoining members, the two outer members being bent outwardly to form spring fingers, and the middle member lying in close lapping proximity to said backing section substantially throughout the entire length of said middle member, and having its inner unattached end adapted to be retained in said plug body in assembled position.

14. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member hav-- ing a main backing section, and a prong section at one end reversely bent, and divided longitudinally to its unattached end to form three adjoining members, the two outer members being bent outwardly to form spring fingers, the middle member being substantially flat and in contact with said backing section, and having at its inner unattached end an ofiset, adapted to be retained in said plug body in assembled position, and to prevent the retraction of said terminal piece into the interior of said plug body.

15. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member having a main backing section, and a prong section at one end reversel bent, and divided longitudinally to its unattached end to form two adjoin= ing members, one of which is bent outwardly to form a spring finger adapted to have its free end spaced from the face end of the plug body in assembled position, the unattached end of the other member extending beyond the free end of said spring finger towards the other root end of the backing section, and being adapted to be retained in said plug body in assembled position.

16. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member having a main backing section, and a prong section at one end reversely bent and divided longitudinally to its unattached end to form two adjoining members, the opposed prong sections of said terminal piece at their socket entry end being crimped into contact with each other, one of said members being bent obliquely outwardly along a straight line to the free end thereof to form a spring finger, the free end of said spring finger being adapted to be spaced from the face end of said plug body to permit transverse spring movement thereof, the other member being flat throughout substantially its entire length and in contact .with said backing section, the unattached nd of said latter member being adapted to be retained in the plug body in assembled position.

1'7. An electrical plug connector oi'the prong type, including a one piece resilient plug body, having a central opening extending to the neck end of said plug body, and a pair of spaced recesses communicating with said central opening, and a pair or terminal pieces each having a backing section frictionally retained in its corresponding recess, and having a reversely bent section forming, with said backing section a prong, said bent section being dividedlongitudinally to form a pair of relatively yieldable spring conltact 18. An electrical plug connector of the prong type including a one piece resilient plug body, having a central opening extending to the neck end of said plug body, and a pair of spaced recesses communicating with said central opening, and a pair of terminal pieces, each having a backing section, frictionally retained in its correhaving a central opening extending to the neck end'oi said plug body, and a pair of spaced recesses communicatingwith said central opening, and a pair of terminal pieces, each having a backing section, frictionally retained in its corresponding recess, and having a reversely bent section, forming with said backing section a prong, said bent section being divided longitudinally to its unattached end to form a pair of adjoining members, one of said members being bent outwardly to form a spring finger, the other member having an inner offset end anchored in its respective recess, and engaging the wall 01 said recess to prevent retraction of said terminal piece into the interior of the plug body.

20. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like membenhaving a main backing section, and a prong section. at one end, reversely bent, and divided longitudinally to its unattached end to form a pair of members, bowed outwardly to form relatively yieldable spring fingers, the inner unattached ends thereof extending parallel to and in contact with said backing section. V

21. As an article of manufacture, a terminal piece, adapted to be retained in a resilient plug body, and comprising a strip-like member, having a main backing section, and a prong section at on: end, reverselybent, and divided longitudinally to its unattached end to form three adjoining members, the ,central member being in close overlapping relationship with said backing section, and having an offset at its inner end for anchorage in said plug body, the other side members being bowed outwardly to form relatively yieldable spring fingers, the inner unattached ends therof extending parallel to and in close overlapping relationship with said backing section, and being adapted to be retained in said plug body.

HARRY CHARMOY.