CA1132217A - Unitary connector receptacle with hinged sides - Google Patents

Abstract

UNITARY CONNECTOR RECEPTACLE WITH HINGED SIDES

ABSTRACT OF THE DISCLOSURE
A dead front connector is provided to include a clam shell type insulating housing. The housing sides fold down by means of integral living hinges. The upper parts of the fold-down sides have internal surfaces which press against and grip the insulation of a cord extending into the housing. Electrical contacts are mounted in the housing in alignment with blade entry ports to permit electrical contact with entering electrical blades.

Description

113,Z2~

UNITARY CON_ECTOR RECEPTACLE WITH HINGED SIDES
This application relates generally to the invention of Ostrelich and Smith, Canadian Application Serlal No: 342,326 - filed December 18/ 1979 -Ostrelich et al, entitled INTERLOCK OR BLADE AND
HOUSING S~DE. It also relates to the Canadian Application Serial No. 342,305 - filed December 18, 1979 - Smith ; et al, entitled DEAD FRONT PLUG WITH CORD STRAIN RELIEF.
It also relates to the Canadian Application Serial No.
342,486 - filed December 21, 1979 - Smith et al, entitled DEAD ~RONT PLUG WITH INSULATION PENETRATING
CONTACTS. Each of these~cross-referenced applications is assigned to the same~assignee as the subject application.
The present invention relates ~o an electrical connector receptac~le and~more specifically to a connector which has a so-called "dead front" construction.
Electrical connector`s~which have dead front construction have no exposed~parts to~which wires are attached other than the electric~blades~which are to~receive power from a receptacle or the openings to the contacts of a receptacle itself. For the subject invention the connector is a~receptacle and no electrical parts appeari on its dead front face~but only the openings for insertion of contact blades are evident in the face.
1 ~ The~concept of~the use of~a~dead front type of construction is that it~increases the safety associated with~the~use of connectors lncluding both;

plugs for receiving electric power and receptacles for deliverying electric power to plugs.
In recent times the standard making organizations of this country and particularly the Underwriters Laboratories, have studied the construction of connectors and have determined that connectors should have a dead front construction. The mandating of the use of dead front connectors by UL was the subject of a recent standard and this standard is now in force.
In designing a dead front connector receptacle to receive a connector plug it is advantageous to limit the size of the connector receptacle. The size must be sufficient to receive the blades of a plug and connector receptacles are usually larger than the insulating housing of connector plugs because they must contain the full length of plug blades inserted therein. By contrast the plug has its blade contacts external to its insulation housing so its housing is relatively smaller in conventional plug and ~0 receptacle connector pairs. The designation of a smaller plug body as compared with the receptacle body is based on axial measurements meaning measurements generaIly along the axis of the blades or along the longitudinal axis of a conductive cord or cable extending from the plug or receptacle.
One patent which describes a dead front plug construction is the U.S. Patent No. 4,010,999 - issued March 8, 1977 - Hoffmann. The construction of the plug of this patent was known prior to the Hoffmann patent and was in fact shown and described in British patent 676,144.
It is one object of the present invention to provide a connector which is economical to manufacture ~ and which is reliable in use.

:

- B

, - . ` , . . . ` .. .. . . . ..

.. . . . .. ,. . .. .. .; , . . ..

1~3Z217 Another object is to provide a connector having a clam shell type construction and having a relatively short length as measured axially of the connector.
A further object is to provide a connector having a dead front type of construction and having no metal objects appearing at the dead front surface of the product.
A further bhject is to provide a connector having a screw terminals and blade contacts where the size of the screw terminal and blade contact is small reIative to the size of those of some prior art structures.
Other objects and advantages of the invention will be in part apparent and in part pointed out in the description which follows.
The present invention concerns a dead ~ront connector as the term deàd front is employed in this art.
The dead front connector has an outer housing in the general form of a clam sheIl type s~ructure.
.
Thè housing of this connector is an elongated three-part insulating plastic housing. It is formed with the three~parts in tandem and with living hinge structure connecting each of the end-portions to the ; center portion.
~ 25 The connector has electrical contacts mounted ~ .
within the structure. The contacts themselves are of .
;~ relatively small size and are formed with contact tines extending from the;contact itself. The contacts with the integral tines~are mounted to~the inner face of the middle portion of the three-portion housing.
The housing is preferably provided with strain relief means by which a wire can be held in the connector securely so as to avoid strain on the contacts.
Also an interlock lS provided between the contact and ; 35 the housing sides. Such interlock prevents separation of the middle portion of the houslng from the remainder :
:
~: B
.~ .

... .. . .. ... ... . . . . .. ... . .. ... .. .. ....... . .. ... . ... . . ... . . . . .

~3~L'7 if the living hinge on each side of the center portion is broken or damaged~ The interlock thus prevents removal o~ the center portion and its contacts mounted thereon from the xemainder of the housing.
The p~esent invention will be better understood by re$erence to the accom,pan~ing drawings in which:
FIGURE 1 is a perspecttye view of a connector havtng a wire extending therefrom.
FIGURE 2 is a side elevatlonal view of the connector o~ FIGURE 1 with the w,ire omitted. A plug is shown also in side eIevational view poised in position for assembly to the connector to bring the power blade of the plug into contact with internal contacts o~ the receptacle. Also the ~ides of the connector are illustrated in the F~GURE in phantom in a partially opened position.
FIGURE 3 ts a top plan view of the connector of F~GURE 1, aga~n with the wire omitted and illustrating ~ the connector housing in a ~ull~ opened position to display ,~ 20 the internal contacts mounted ~ithin the receptacle housing.
FIGURE 4 is a pers,pectiVe view of one form of contact usable tn th,e connector of FIGURES 1, 2 and 3.
FIGURE 5 is~a Yertical sectional view of a portion of the connector taken along the line 5-5 of FIGURE 3.
~ FI-GURE 6 is a vertical sectional view of '~ another portion of the cQnnecto~ taken along the broken line 6-6 of FIGURE 3.
Referring first to FIÇURE l a connector 10 is illustrated in perspective'Vie~ with a two-strand wire 12 extending thère~ro,m,,the ~ire having two conductors 14 within the outer sheath Qf wire 12. The connector 10 is ~ade up of an outer insulating housing having a base 35 poxtion 16 and two si-de'portions 18 and 20. T~o screws 22 serve to hold the'connector 10 in an assembled ~322~'7 position when a wire such as 12 has been connected thereto. The base 16 i5 a midportion of a single housing and the si,des 18 and 20 are end portions connected to the midportion 16 by two living hinges 24 and 26. The base or midportion 16 o~ the h,ousing has -two blade entry ports 28 and 30. ~t w:ill be obserYed that the port 28 i$ o~ slightly smaller length than the port 30. This signifies that the ports are polarized, that is, that the port 28 xeceiYes a s,maller po~er blade and the port 30 receives a larger power blade o~ the conventional polarized poWer blade of the conventional polarized power blades as employed in the ~iring advice industry.
Considering next FIGU~E 2, the connector 10 is illustrated in the upper portion o~ the Figure without a ~ire emerging therefrom. At the lower portion of the Figure a portion of a plug 32 is illustrated beneath the connector 10. The plug is t llustrated t n a position for insertion of the power blades,,34 into electrical contact ; ~ith appropriate contacts within the connector 10. The , 20 connector 10 has a housing made up o~ the three portion~
and more specif~cally the` two fold-up end portions 18 and 20 and the ~idportion 16. The end portions 18 and 20 are sho~n in solid line in the assembled position with the scre~ 22~in place holding the two end portions together. In FIGURE 2 the t~o end portions 18' and 20' are shown in their opened po,s,ition hinged open about the two living hinges 24 and 26. Also the plug 32' is lllustrated aboye the solid line plu~ 32 to displa~ the position that plu~ 32 would occupy when the plug is -30 assembled to the connector for electrical contact between the conducting elements thereo~. The blade 34 o~ plug 32 is shown in phantom as blade 34' within the body of connector 10. ~hen in the inserted position the blade 34' makes contact with the internal contacts ,~ 35 36 and 38 of~connector 10. These contacts are'shown in ~ solld line in the broken-a~ay portion of the housing.

~3Z~17 The actual contact between inserted blade 34' and the internal contact 36 of connector 10 is at a lower portion of contact.36 illustrated in phantom in FIGURE 2.
The alignment o~ the contacts in connector 10 is more readily ~yident from FIGURE 3 which is a top plan View of the connector lO in a ~ully opened position.
~s is e~ident from ~GURE 3 the connector lO has three portions 16, 18 and 20, the three portions being held to~ether b~ th.e two living hinges 24 and 26. The center portion 16 has formed therei'n and extending therethrough the t~o blade ports 28 and 30. The center section 16 ~ also has formed as a part of its inner surface means ~or :l supporting in place'on the center section interior,.the : t~o contact elements 36 and.38.
. 15 The contact elements 36 and 38 may be best described with reference to FIGURE 4 wherein a single contact is shbwn in pexspective yiew. The contact of FIGURE 4 is used in duplicate in the connector as the' sing].e part seryes both'positions. ~ith,in the connector body. In other words:the s,in~le ormed part is used as ~ the contact 36 and is also used.as the contact 38.
.. As is evldent:,,the contact of FIGURE 4 is made ."~: up from~a single strip of metal and this single strip is ~ bent and shaped into the contact 38. A terminal strip .l ~ 25 40 has a threaded opening 42 formed therein for mounting of a scre~ member 44 therein. Screw 44 has head 46 on ~ -the opposite side of terminal~strip 40. Strip 40 has : t~o lo~er offset arms:48 and 5~and'has two depending~
cont~act tines 52~and 54 descendin~ from the offset:arms 48 and'50 respecti~ely. The terminal str~p portion 40 has:two anchor elements 56 extending from one lateral : edge and two additional anchor elements 58 extendin~ out ~ throu~h'the other ed~e. These ele~ents serye as self:
':::~ -lock~ng teeth to anchbr the terminal strip into place:in a conforming undersized reces.s formed in the base l6~o~
the'i,nsulating housing of the connector 10.. ~n other `
~ .. ... ..... . .. . .. ..

: . . ~ . . ., ~ . . . ,... ,. - :.: : .

.. . , . ~. : - . . : . . : . .. .: , . -1~3~l7 words, once the element such as 56 o~ FIGURE 4 is placed in a slot 60.formed inte~rally in the base 16 o~ the insulating body of connector 10 it remains in plce and is not removed due to normal use. As is e~ident principally ~rom F~URE 5 the insertion of the strip 40 into slot 60.causes. the gripping teeth 56 and 58 to engage the material of th.e base 16 and prevents the removal of the. terminal 38 fronl its position in base 16.
Also cooperating in the retention of the terminal 38, as ~eIl as terminal 36, in the base 16 of connector 10 is the pair of tabs 62 and 64 ~ormed integrally ~ith the strip 40 but bent at approximateIy 90.degrees ~rom the top sur~ace thereof. The tabs 62 and 64 of terminal 38 interlock With the conforming : 15 recesses 66 and 68 in the ribs 70 and 72 ~ormed inte~rally in the side portion 20 of the insulating : housing o~ connector 10.
~ 1 Similarly the tabs 74 and 76 of the contact 36 :~ are ~ormed to interlock ~lth the recesses 78~and 80 of :~: 20 the ribs 82 and 84 formed integrally w;ith ~side portion ~ : 18 of insulating housln~ o~ connector 10.~ Interlocking ~: of the tabs 62 and 64 into:the recesses 66 and 68 provide a rein~o;rcement bet~een the contact 38 and the side~all 20 of the deyi:ce. Thus when a power blade is ; 25 inserted thrcugh the openlng 30 in base portion 16 it contacts the tines 52 and:54 and tends to push them : upward:. Ho~ever, such pushing is resisted because the strip~40 is anchored ~n the conforming reces.s 60 and in ~`; addltion because the tabs 62 and 64 are disposed within .~ 30. the recesses 66 and 68 of the side wall ribs 70 and 72.
Similarly, rein~orcement~bet~een contact 36 is provided by the interlock o~ the tabs 74 and 76 in the ~ . recesses 78~and 80.o~ the xlbs 82 and 84 of side ~all 18.
: ~ This interlock is also:evident in FIGURE 2 ~here the tab : 35 76 is shown positl~oned within the recess 80 and the ... tab 64 is illustrated positioned within the recess 68 :

~3;~Z~7 of side uall 20.
The contacts 36 and 38 provided by the subject invention are some~,hat unique in their economy of material and effecti~eness in use. Thus the scre~ is seen to be disposed someuhat off center with respect to the contact strip and thi,s i5 evident particularly in FIGURE 5. It is also evident that a blade entering the blade port 30 w~ll pass up and into contact with,'the tines 52 and 54 and will then actually pass up into a position adjacent to the shank 44 of the screw. This compactness of desi~n permits the overall length o~ the connector to be minimized and yet provide a thoroughly effective mechanism for electrical connection o plug blades inserted thereinto. It is evident that the tines 52 and 54 are urged touard each other by spring pressure and that a blade entering therebetween will spread the ~ tines to permit a ~ood spring contact bet~een the tlne ;~ portion of the contact strip and the blade entering "~ thereinto.
~ 20 Accordingly there is a one-piece housing made up ,~ of the three portions connected by the living hinges and there are two relatively small contact elements mounted ~ithin the housing.~ Tuo screus assemble the connector ~ to provide an effecti,ve closure thereof, so that the ,~ 25 user is af~orded a great deal of convenience and reIiability while at the same time having a structure ~ which is economical in material, in time consumed for '~ assembly and in utilization. As is also evident from ~` FIGURE 3 the screu terminals are separated within the housing and are disposed on opposite sides o~ the dead front center section I6 thereby reducing potential probl`ems relating to shorting o~ stray wire strands.
The housing of the connector 10 hàs openings 86 in side portion 18 and has screu receiving ~eIls 88 i,nside'portion 20 to receive the thread of the screUs extending lnto the houslng through'the opening 86. The :~ :

:,, , ~. : ~ . .:, . ; - :. . ,,: ..... , : : . . . , :.
: : - .,: . .-. .,. : . ... - : .. ~ , .. . . .

2~'7 housing is further provided ~ith cord grip mechanism at the outer ends o~ the side portions 18 and 20 and with the coxd opening 90 inside portion 18 and 92 inside poxtion 20.

, ~ ~' `':

:

`: :

.. . . . . . . . .. . . . ... . . .. . .

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A dead front electrical connector comprising an insulating housing made in three sections in tandem joined by two living hinges disposed between adjacent sections, the center section forming the dead front end of said connector, a first end section adapted to be folded up to form one side of the housing of said connector and a second end section adapted to be folded up to form the other side of the housing of said connector, means for joining the folded up first and second end sections to close said housing, said center section being provided with blade entry ports adapted to receive power blades therethrough, a pair of blade contacts mounted in said housing on the interior of the center section, said contacts having a pair of contacts tines on opposite sides of the interior of the blade entry ports.

2. The connector of claim 1 in which each contact is mounted in the interior of the center section by a press fit.

3. The connector of claim 1 in which the contacts are formed with screw terminals.

4. The connector of claim 1 in which the contact tines are generally perpendicular to the external dead front face of the center section of the housing.

5. The connector of claim 1 in which screw terminal strips are formed integrally with the blade contacts and are disposed toward the outer edges of the center section.

6. The connector of claim 5 in which the screws of the screw terminals are oppositely extending.

7. The connector of claim 5 in which the longitudinal axis of the screw of the screw terminal is generally perpendicular to the longitudinal axis of a blade contacting said tines and the two longitudinal axes are non-intersecting.