Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TWIST TYPE EIECTRIt:~ RECEPTP.CLE
The invention relates to an improved twist-type
receptacle for an electrical conn&ctor which i~ fab~i~
cated as a one-piece member and wherein the terminals
axe self-captivating. It is particularly adapted to
5 receive ~ photoelec~ric controlle.r in a lighting lumi-
naire .
Electrical connectors which are locked by twistirlg
are well-known in the art and axe commonly used to pre-
vent accidental separation of the plu~ from the recep-
~acle. In order that components made by dierent manu~
factur2rs be interchangeable, the configuration and
spacing of male and female contacts in such connectors
is largely dictat2d by standards adopted by National
Electrical Manuacturers Association (NEMA)o Notwith-
standing such standardization, there remains substantial 'i
~ scope or improvement in khe design o the parts to
; achieve greater reliability, to facilitate manufacture,
and or ease and convenienee in a~sembly. - 1,
In linear type connectors, that i5 in connectors
wherein the plug i5 mexely pushed into the receptacle
and is not ~hexeaft r twis~ed in order to lock i~, ~he
U54 0~ self~ aptivating terminals is well-known. ~ow-
ever wi~h twist~ype conne~tors in which the contac~
are subject to both linear insertion and then rotation,
, ~
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it has not up ~o the present been possible to use self-
captivating terminals. A~ a result, the insulating body
of the receptacle has generally ~een made of several
pieces, for instance a body piece ha~ing cavities in
which the ~erminals are inserted, and a cover which is
then fastened to the body in order to lock the terminals
in the caviti~s. This has meant more complicated as-
semblies and has increased the cost of manufacture.
SUMkl~RY OF T~E INVENTI ON
The object of the invention is ~o provide a twist~
type receptacle for an electrical connector of which the -.
body consists of a single piece of insulating matexial
which is readily formed and wherein the terminals are
sel~-captivatedO .-
In accordance with the invention, the receptacle is .
f~bricated as a one-piece memher having several through
apertures or passages the walls of which are pxovided
with ledge~. The terminals comprising contacts for en-
gaging those of the plug in its push in and twist motion.;
are provided with rearwardly directed resilient ears or
barbs which lock the terminals in place by engaying the
ledges.
In a preferred embodiment the receptacle has three
- through passages the walls of which are provided with
ledges. The terminals comprise curved twin-blade female
contacts fox ac~ommodating the blades of the plug and .
have barbs which initially ride over the ledges when the
terminals are inserted into t~e passages. Upon passing
over the ledges in the longitudinal direction of terminal
inser~ion, the baxbs spring laterally outward ~ehind the
ledges thereby captivating the terminals. Over-insertion
of the terminals in the forward direction i5 prevented
by means of web portions which are integrally formed in
con~unction with the passages. In this manner the ter-
minal~ cannot be removed either in the forward or rear-
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ward directons. Keying tabs may be provided upon the
terminals in order to facilitate assembly.
DESCRIPTIOI_OF D~WING
FIG. 1 is an exploded view in perspective .~howing a
female receptacle embodying the inv~ntion and a mating
male plug.
~ IG. 2 is a perspective view of a self-captivating
~erminal used in the receptacle.
FIG. 3 is a frasmentary sectionalized perspective
view showing the terminal captivated in one of the pas-
sages through the recep~acle.
DETAILED DESCRIPTION
For purposes of illustration, a two-part electrical
connector 1 is shown in FIG. 1 comprising complementary
male plug 2 and ~emale receptacle 3 facing.each other in
exploded relationship. The male plug ` includes a base
member 4 ~ insulating material such as nylon surmou~ted
by a cylindrical housing 5. The base member has three
male contact blades or prongs 6, 7 and 8 extending down
from the face thereof in a standard Nema configur~tion.
Where plug 2 corresponds to a photoelectrlc contrcller,
the housing 5 encloses suitable photoelectric control
components i~ electrical circuitry with the contact mem-
bers~ Alternatively the contact members may be connected
25 to conductors of a cable or may be merely short-circuited
toge~her where plug 2 is a shor~ing plug and ~he photo-
electric sontrol is dispensed with~ `
The receptacle 3 in which the invention is directly
embodied is a one~piece me~ber of insulating ma~erial,
;30 preferably one which is non tracking and thus non-shorting.
The face portion 10 of the receptacle contains spaced .-
arcuate slots 12, 13 and 14 which lead into passageways
within the body portion 11 housing the terminals having
female contacts which accomm~date the mating blades 6, 7
F~
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....
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and 8 of the plug. These terminals have conductors at-
tached to them which, in the case of a photoelectriG con-
troller, are connect2d into the lamp circuit of the lu-
minaire~
The invention is predicated on the design of the
ter~inals as shown at 15 in FIG. 2, in con junction with
that of the acc:o~nodating passage or chamber 16 in the
receptacle body as shown in FXG~ 3. Terminal 15 is a
one-piece strut:ture blanked out of sprîng metal stock,
for instance phosphor bronze or alternatively spring
s~eel plated to increase its electrical conductivity and
resistanc2 to corrosion. The terminal is generally
channel-shaped in its mid-portion with a front wall 17
and side walls 18. The side walls extend upwardly into
converging portion~ 19, parallel portions 20 and di~erging
portions 21. The vertical portions 20 constitute the
female contact portions which are penetra~ed by one of
the male conta~t members 6 to 8. A wire attaching means
takes the form of a crimping lu~ portion 22 which extends
20 down from the ~ront wall 17 and is crimped about a con-
ductor 2 3 .
As seen in FIG. 1, each of the male contact members
is essentially an L-shaped blade of arcuate cross sec~ion
and includes a vertical leg portion 24 terminated by a
horizontal lug portion 25. The lug portion projects
forwardly in the direction of twist or rotation of the
plug relative to the receptacle, such being clockwise as
illustxated. The contact members 6 to 8 are of sufficient
len~th nd thickness to extend through the slots 12 to
14 in the receptacle and to be resilien~ly received be-
tween the pairs of ~ertiçal contact portions 20 of the
terminals. The curving slots 1.2, 13 and 14 in the re-
ceptacle face have an arcuate length such that after full
insertion of thP contact members, the plug 2 may be
35 twisted (clockwise) relative ~o ~he recep~acle 11 and
., .. ., .. . .. .. . _ . . ... _ .. .. , .. ....... _ ...... . . ........ ... .. ...... ......... . . ... ....
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the lug portions 25 of khe male contact members 6, 7
and 8 will engage the underside 26 of the face or web
l0 of the receptacle. This locks the parts together ~o
they cannot be pulled apart.
When the plug is initially pushed down into the re-
ceptacle, the lug portions 25 slide down between the
vertical portions 20 of the te~minals, and then as the
plu~ is twisted the vertical leg portions 24 of the con-
tact members move in a~ indicated by curved arrow 27 in
FIG. 2. When the plug is fully home ~about 20 twist),
the hole 28 in the male contact members i~ engaged by
dimple 29 in the outer or convex female cont2ct and this
provides a minor locking effect preventing untwisting
of the part~ except by deliberate application o~ force.
Arcuate slots 13 and l4 are identical, but slot 12 is
slightly longer in ordex to accommodate male contact
member 6 which is lo~ger axially and has a greater ~r-
cuate length than the others, thereby providing for a
polarized receptacle~
In accordance wi~h the invention, terminal 15 is
; pxovided with a laterally projecting rearwardly dire~ted
barb or resilient ear 31 in at least one and preferably
both of its sidewalls 18. Correspondingly, the passage
ox chamber 16 into which the terminal i5 inserted is pro-
vided with a ledge 32 for each barb extending ~rom the
bottom of body ll up to the rest location of the barb
when the terminal is in place. The terminals are in-
sexted into the passages l~ in the body from the und~r-
side and the barbs initially ri~e over the ledges. Upon
passing the ledges in the direction of ~erminal insertion
~upward), the barbs spring laterally outwaxd behind the
ledges, thereby captivating the terminals. Over-insertion
of the terminals in the forward direction i5 prevented
: by the web portions 26 which are integxally fo~ed in the
face of the re~eptacl~ at the same time as the passages
....... ,.... _.. =. . ~ ~_ _.. __ _, _ _ . __ , __ _ _,,, ., ,,.,.. ,. ,.. , , , . _., .
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16 are molded in the body. The transverse 510ts 33 in
the face of the receptacle and into which the arcuate
slots extend are necessary because the die member for
molding the ledges 32 within the passages 16 must be
inserted and withdrawn from above. A keying tab 34 pro~
jects from the front wall 17 of the terminal and rides
in a slot 35 formed in the wall of cavity 16. It assures
proper orientation according to pian when a terminal 15
with at~ached wire 23 is inserted into one of the passages
16. Also the tab makes the terminal more stable in its
cavity. Once captivated in the passage, a texminal can
only be removed by using a special tool to squeeze back
~he barbs 31.
The invention thus provides a reliable twist-locX~
ing type receptacle particularly suitable for accommodating
a photoelectric controller. The flange 36 surrounding the
face 10 has holes 37 in it for convenience in fastening
the receptacle to a panel. Such flanye may be omitted
where the receptacle is used as part of an electrical con-
nector only. The assembly of the terminals having pre-
attached wires to the receptacle is readily done without
requiring use of any special tools and a more flexible
approach to assembly procedures is made possible.
The preferred embodiment of the invention which
25 has been illustrated and described in detail is intended
by way of example only and various changes and modifica-
tions may be made therein without departing from the scope
or spirit of the invention.
