Note: Descriptions are shown in the official language in which they were submitted.
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;
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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.
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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
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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$erence to the accom,pan~ing drawings in which:
FIGURE 1 is a perspecttye view of a connector
havtng a wire extending therefrom.
FIGURE 2 is a side elevatlonal view of the
connector o~ FIGURE 1 with the w,ire omitted. A plug is
shown also in side eIevational view poised in position
for assembly to the connector to bring the power blade of
the plug into contact with internal contacts o~ the
receptacle. Also the ~ides of the connector are
illustrated in the F~GURE in phantom in a partially
opened position.
FIGURE 3 ts a top plan view of the connector of
F~GURE 1, aga~n with the wire omitted and illustrating
~ the connector housing in a ~ull~ opened position to display
,~ 20 the internal contacts mounted ~ithin the receptacle
housing.
FIGURE 4 is a pers,pectiVe view of one form of
contact usable tn th,e connector of FIGURES 1, 2 and 3.
FIGURE 5 is~a Yertical sectional view of a
portion of the connector taken along the line 5-5 of
FIGURE 3.
~ FI-GURE 6 is a vertical sectional view of
'~ another portion of the cQnnecto~ taken along the broken
line 6-6 of FIGURE 3.
Referring first to FIÇURE l a connector 10 is
illustrated in perspective'Vie~ with a two-strand wire
12 extending thère~ro,m,,the ~ire having two conductors 14
within the outer sheath Qf wire 12. The connector 10 is
~ade up of an outer insulating housing having a base
35 poxtion 16 and two si-de'portions 18 and 20. T~o screws
22 serve to hold the'connector 10 in an assembled
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position when a wire such as 12 has been connected
thereto. The base 16 i5 a midportion of a single housing
and the si,des 18 and 20 are end portions connected to the
midportion 16 by two living hinges 24 and 26. The base
or midportion 16 o~ the h,ousing has -two blade entry
ports 28 and 30. ~t w:ill be obserYed that the port 28
i$ 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.
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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
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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
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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
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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.
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