Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~13~547
This invention relates to a zero insertion force
electrical connector.
There is known, a zero insertion force electrical
connector comprising an insulating housing body part,
a row of electrical terminals fixedly mounted in the
housing body part and an insulating lever which is
pivotable about a fulcrum on the housing body part,
each terminal having an elongate resilient contact
portion proiecting into an opening in the housing body
part, through which opening a male contact member can
be introduced along an insertion path, the lever being
engaged with the contact portions of the terminals in
such a way that in a first angular position of the le~er
- the contact portion of each terminal is withdrawn from
the insertion path and in a second angular position
of the iever, the contact portion intersects the
insertion path,.each terminal having a locking portion
disposed externally of the housing body part and being
adapted to be force fitted into a support for the
connector.
The support will usually be in the form of a
circuit board to printed conductors of which the terminals
are soldered when the locking portions have been force
fitted into the support.
-Since such a connector is usually of miniature
size, and the terminals are densely spaced, it ~s the
pr.actice to assemble the terminals to the support prior
- 2 - ~
113~547
to assembling the housing to the tenminals. This is
because the high insertion forces that are required
to drive the locking portions of the terminals into
the support would tend to damage the housing of the
connector, especially in the case of slight misalignment
of the insertion tooling, if the housing were to be
assembled to the connector prior to the assembly of
the terminals to the support.
The present invention proceeds from the realization
that the connector should preferably be supplied to
the end user in a fully assembled condition, in
readiness to be mounted to its support by the end user,
and that it should accordingly be ensured that the
insertion forces are applied directly to the terminals,
to avoid the terminals being dislodged from the
connector, to avoid undue force being exerted against
any plastics and inherently fragile parts of the
connector, and to avoid undesired disassembly of the
plastics parts. Thus, for example/ the levers are
fragile and are easily dislodged or damaged.
According to one aspect of the invention,
therefore, in a zero insertion force electrical connector
as defined in the first paragraph of this specification,
each terminal is provided with a seat for a tool which can
be inserted throu~h the opening to force the locking
portion ol the terminal into the support.
- The housing body part is preferably provided
.
~3~5~7
with resilient means urging the lever against the
fulcrum.
,According to another aspect of the invention,
a zero insertion force electrical connector, comprises
an insulating housing body part including first and
second elongate side walls secured together in
parallel spaced relationship, and a row of elongate
resilient electrical terminals between the side walls,
each terminal comprising, a contact surface intermediate
its ends for engaging a male contact member when such
has been inserted between the side walls along an
$nsertion path extending transversely of the row of
terminals, a locking portion for forcible insertion
into a support for the connector, a root portion
remote from the contact surface and by means of
which the terminal is fixedly located between the
side walls, and a free end portion, the contact surface
being positioned between the free end portion and the
root portion, and the locking portion being positioned
on the side of the root portion, remote from the free
- end portion and externally of the housing body part,
there being attached to the housing body part, a
shroud having a depending margin engaged about the
~ree end portions of the terminals and a pivot member
remote from the depending margin, engagi~g a ~ulcrum
on the housing body part, a cam mounted between the
s~roud ar.d the ad~acent side wall being movable to pivot
4 --
113854q
the shroud between a first angular position in which the
contact surfaces are withdrawn from the insertion
path and a second angular position in which the
contact surfaces intersect such path; wherein each
terminal is provided between its root portion and its
contact surface with a seat for a tool which can be
inserted along the insertion path to force the locking
portion of the terminal into the support, the adjacent
side wall having a resilient projection extending
through a support for the cam and engaging the shroud
resiliently to urge a lip thereon into a recess in
the fulcrum, thereby to secure the shroud to the
housing body part.
As described below, it is a particular advantage
of this aspect of the invention that the effective
lever length of the resilient projection is desirably
long. The resilience of the mounting of the shroud
to the housing body part and thus the protection of
the shroud against vibration arising from the insertion
forces is thereby enhanced.
For a better understanding of the invention
two embodiments thereof will now be described by way
of example with reference to the accompanying drawings
in which:-
Figure 1 is an enlarged perspective view,
showing part broken away, of a stackable, zero insertion
- force electrical plug receptacle connector according
-- 5 --
~13~54q
to a first embodiment of the invention, ir. a closed,
plug contacting position;
Figure lA is a fragmentary perspective view of a
detail of the connector of Figure 1, drawn to a
reduced scale;
Figure 2 is an enlarged cross-sectional view of
the connector of Figure 1 when mounted on a printed
circuit board and showing part of a tool in use in the
insertion of terminals of the connector into holes
in the printed circuit board;
Figure 3 is a similar view to that of Figure
2, but in which the tool is not shown, the connector
being shown in stacked relationship with a further
and similar connector (only part of-which is shown)
wh~ch is also mounted on a printed circuit board;
Figure 4 is a similar view to that of Figure
2 but in which the tool is not shown and in which the
connector is shown in an open, plug receiving position;
Figure 4A is a fragmentary sectional view
taken on the lines IVA - IVA of Figure 2;
Figure 4B is a fragmentary sectional view taken
on the lines IVB - IVB of Figure 4;
Figure 5 is a fragmentary cross-sectional view
illustrating the assembly of a part thereof to the
connector;
Figure 5A is a f.ragmentar$~ sectional view taken
on the lines VA - VA of Figure 5;
-- 6 --
1138S47
Figure 6 is an enlarged perspective view of a
terminal of the connector; and
Figure 7 is a view similar to that of Figure
4 but illustrating a second embodiment of the connector
in association with an edge portion of a printed circuit
board which the connector is adapted to receive.
Reference will now be made to Figures 1 to 6.
A stackable, zero insertion force electrical
plug receptacle connector 1, comprises an insulating
housing containing two rows of terminals 2. Only one
terminal of each row is shown (Figures 2, 3 and 4).
Each terminal 2 comprises, as best seen in
Figure 6, an elongate, resilient contact part
consisting of a free end portion 4 having a bight
defining a depression 6, a bowed portion defining a
convex contact surface 8, and a shank 9. The shank 9
is connected to a bight 14 of a widened, tool-receiving,
portion 10 having a central longitudinal blind slot
12, one rounded end 13 of which extends into the ~ight
1~. The other end 16 of the slot 12, which end is
also rounded, provides a tool seat, as described below.
The end part 18a of the portion 10, remote from the
shank 9, has, struck out therefrom, a retaining
tongue 18 disposed between the end 16 of the slot 12
2~ and a locking portion 20 of the terminal. The
portion 20 is bifurcated, to provide a pair of
oppositel~ bowed legs which are resiliently deformable
'1138547
towards one another, these being connected at one end
to the part 18a and at the other to a male contact
member in the form of a rectilinear plug 22 of the
terminal.
The connector 1 has an insulating housing
which includes a one piece, moulded, elongate body part
24 having a pair of upstanding, parallel side walls
26 which are spaced from one another in the transverse
direction of the part 24 in substantially parallel
relationship, and a longitudinal barrier wall 28
having a chamfered tip 31 and being disposed midway
between the side walls 26. The wall 28 is connected
to thebwalls 26 at either end by respective blocks 29
and 29' (Figures 1, 4 and 5). A series of longitudinally
lS spaced, transverse webs 32 formed integrally
with the walls 26 and 28, define a row of cavities 30
on either side of the barrier wall 28, as best seen
in Figure 1, these cavities extending ~ertically (as
seen in Figures 2 to 4) completely through the body
part 24 of the housing. The wall 28 has opposed
abutment faces 31A in a widened, receptacle portion
30B of each cavity 30.
As shown in Figures 5 and 5A each web 32 has
a lower (as seen in Figure 5) thickened portion 34 having
opposed recesses 34A (Figure SA). Reducçd width
portions 30A of the cavities 30 extend between adjacent
portions 34. Each barrier wall 28 has a vertical
-- 8
113~S4`7
(as seen in Figure 5) groove 28A communicating with
the adjacent cavity portion 30A. A thickened wall
portion 36 extends along the bottom part of each side
wall 26 and is provided with a vertical slot 38
opposite to each cavity 30. Formed integrally with
each wall 26 is a thin, stiffly resilient finger
40 which projects laterally therefrom and extends
through the adjacent slot 38 and beyond the wall
portion 36. -Each finger 40 is of substantially
S-shape as seen in longitudinal section, having near
its free end, a bight 40A having an upwardly (as
seen in Figures 2, 3, 4 and 5) directed crest 40B.
Each wall portion 36 has, as best seen in Figure 1,
projecting laterally therefrom, on either side of
each.of its slots 38, a pair of longitudinally
extending ful~ra in the form of hook-like projections
42, the free ends 42A of which extend towards the
fingers 40. Each projection 42 is undercut to provide
a r-ecess 42B. The upper (as seen in ~igures 1, 4 and
5) end of each wall portion 36 defines a series of
planar shelves 44, above each of which protrudes
laterally from the side wall 26, a rectangular
projection 46.
The ~iall 26 has a flat lower face 26B, the
wall 28 having a flat lower face 28B, the faces 26B
and 28B being coplanax.
In order to assemble the terminals 2 to the
_ g _
~13~S4`7
body part 24, each terminal 2 is inserted, with its
plug 22 leading, into one of the cavities 30, from
that end of the cavity 30 which is adjacent to the
tip 31 of the wall 28, towards the lower face 28B
thereof. As best seen in Figure 5A, the widened
portion 10 of the terminal 2 slides during the
insertion of the terminal 2, into the recesses 34A
of the thickened portions 34 of an adjacent pair of
the webs 32, the tongue 18 of the terminal 2 wedgingly
engaging the adjacent wall 26, in the cavity portion
30A to restrain the terminal 2 against withdrawal
from cavity 30. The terminal 2 is accordingly fixedly
located in the housing, with the con'act surface 8
of the terminal disposed opposite to one of the
abutment faces 31A of the wall 28 and the free end
portion 4 of the terminal 2 projecting beyond the
adjacent side wall 26 so as to be substantially level
with the tip 31 of the wall 28. The locking portion
20 and thus the plug 22 of the terminal 2, then lie
outside the housing beyond the faces 26B and 28B, of
the walls 26 and 28.
As best seen in Figures 1, lA and 5, the housing
of the connector 1 also includes a one piece, insulating,
cam member 48 comprising a pair of elongate cam plates
50 connected together at their left hand (as seen in
Figure 1) ends by a we~ 52 from which extends a platform
54 provided with an operating handle 56 joined to the
-- 10 --
113~S4~7
web 52. - -
As shown in Figure 1, the platform 54 hasa channel-like track 58 slidably receiving a rail 60
formed integrally with, and projecting axially from,
the end wall 29 of the housing part 24. Each cam
plate 50 is, as shown in Figure lA, 4A and 4B, provided
with a series of ramps 62 extending, and being spaced
from one another, longitudinally of the plate S0.
A stop wall 64 is provided at the thicker end 62A
of each ramp 62.
The cam member 48 is assembled to the housing
part 24 with the cam plates 50 slidably received
therein so as to rest on the shelves 44 and to seat
against the side walls 26.
The housing of the connector 1 also includes
one piece cam follower levers in the form of a pair
of insulating shrouds 66. Each shroud has a top (as
seen in Figures 1, 2, 3, 4 and 5) wall 68 having a
depending longitudinal margin 70, which, when the
shrouds 66 have been assembled to the body portion 24,
engages over, i.e. is hooked over, the free end portions
-4 of the terminals 2 of one of the rows thereof, with
the free end portion of the margin 7 in the depression 6
of the terminal 2. Connected to, and extending
2~ perpendicularly from, the top wall 68 of each shroud
66 is a siae r,Jall 72 having a row of apertures 74
extending lengthwise of the connector 1. There projects
-- 11 --
~13t~547
from the lower edge of each aperture 74, a pivot
member in the form of a lip 76 which is inclined
inwardly of the housing and has a rounded tip 77. The
end 78 of the wall 72, remote from the top wall 68
is also rounded.
In order to assemble each shroud 66 to the
housing part 24, the margin 70 thereof is first hooked
over the free ends of the terminals 2 (as shown in
Figure 5), of the corresponding row and the shroud
66 is then pivoted about the bottoms of the depressions 6
of these terminals to cause the end 78 of the wall 72
of the shroud 66 to engage the crests 40B of the fingers
40 of the adjacent wall 26, resiliently to deflect these
f$ngers away from the projections 42, there above,
so that these projections enter the apertures 74,
and the rounded tip 77 of the lip 76 enters the
recesses 42B of the projections 42, being retained
therein by the resilient action of the fingers 40
agair.st the end 78 of the wall 72. The free end
portions 4 of the terminals 2 are also deflected
resiliently to allo~ the projections 42 to enter the
apertures 74, and therefore assist the action of the
fingers 40 in retaining the tip 77 in the recesses 42B.
Each shroud 66 can readily be released from
the housing part 24 by prying the end 78 of the shroud
66 to cause the lip 76 to snap out from between the
f.ingers 40 and the projections 42.
- 12 -
113~547
Since the fingers 40 are formed on the walls
26 themselves rather than on the wall portions 36,
these fingers are of suitably long lever length.
Each terminal 2 can be withdrawn from the housing
part 24 by engaging a hooked tool end (not shown~
in the slot 12 of the terminal 2 and then withdrawing
the tool.
As will be apparent from Figure 2, the plugs
22 of the terminals 2 of the fully assembled connector
can be simultaneously locked into holes 86 in a printed
circuit board 88 positioned beneath the connector 1,
by means of an insertion tool 80. The tool 80 is of
elongate (in the longitudinal direction of the
connector 1), rectangular shape and comprises an anvil
block 82 from opposite sides of which depend
rectilinear, terminal insertion blades 84, the total
number of these.blades being equal to that of the
ca~ities 30 of the housing part 24.
The plugs 22 of the terminals 2 are first
inserted into the holes 86 until the locking portions
20 rest against the upper (as seen in Figure 2) face
of the board 88. Each blade 84 is then inserted into
a cavity 30 so as to pass between the contact surface
8 of the terminal 2 therein, and the adjacent surface
31A of ~he wall 28 (as shown in Figure 2), so that
the tip 84A o~ the blade 84 enters the slot 12 of the
terminal, and seats against its end 16. The tip 84~ is
~3~547
arcuate so as to correspond to the curvature of the
end 16. The block 82 is now depressed, for example
by means of a power driven ram (not shown), to force
each locking portion 20 into a hole 86 there beneath,
whereby the legs of the portion 20 (which is initially
substantially over sized with respect to the hole 86)
are resiliently forced towards one another so that the
portion 20 is securely locked in its hole 86.
Although high insertion forces are required to
insert the portions 20 into the holes 86, the connector
is protected from d~mage, since the insertion forces are
applied directly to the terminals and not to the
housing and the blades 84 are supported against the
abutment surfaces 3L~ of the central barrier wall 28
to restrain the blades from buckling, the terminals
2 serving to urge the blades ~4 against the surfaces
31A. The blades 84 are flexible enough to allow them
to be deflected slightly, initially to align them with
the ends 16 of the slots 12.
By virtue of the secure and resilient engagement
of the tips 77 of the lips 76 in the recesses 42B
of the projections 42, ad~itional assurance is provided
that the shrouds 66 are not dislodged ~rom the housing
part 24, or dama~ed, as a result of the vibration
arising from the application of the high insertion
forces.
In tlle fully inserted position of the portions 20,
- ].4 -
113~S47
the faces 26B and 28B engage the upper surface
of the board 88.
The connector 1 can be placed in an open, plug
receiving condition (Figure 4) by sliding the cam
member 48 (from its Figures 1 and 4A position) along
the rail 60 in the direction of the arrow 90 in Figure
1, to cause the cam plates 50 to be withdrawn from the
housing part 24 so that the thicker ends 62A of the
ramps 62 engage the projections 46 (Figure 4B),
to force the shrouds 66 angularly away from one another,
and thus away from the walls 26, the shrouds 66 swinging
about the pivotal axis provided by the tips 77 and
the floors of the recesses 42B. The depending margins
70 of the wall 68 thus pull the terminals away from
the barrier wall 28 as shown in Figure 4, to allow
a plug to be inserted between the wall 28 and the
contact portion 8 of each terminal, substantially
without insertion force. The outward movement of
the cam member 48 is limited by the abutment of the
stop walls 64 of the plates 50 against the projections 46.
The contact portions 8 of the terminals can be
made operatively to engage the inserted plugs by
returning the cam member 48 to its initia3 position
so as to return the shrouds 66 to their initial
positions. The colmector is then in a closed plug
contacting position.
As shown in ~'igure 3, the connector 1 described
- 15 -
113~547
above may be mated in stacked relationship with a
further and similar connector LA, mounted on a printed
circuit board 88A, the plugs 22A of the terminals 2A
of the connector lA being inserted along insertion
paths, in the directions of the arrows 51 in Figure
4, into the cavities 30 of the connector 1 when in its
open, plug receiving position (Figure 4~ and the
connector 1 there after being placed in its closed
plug contacting position (Figure 3).
According to the embodiment of Figure 7, a
zero insertion force connector lX is adapted to
receive a male contact member in the form of a printed
circuit board 92, instead of electrical plugs as in
the case of the first embodiment. To this end, the
barrier wall 28X terminates at a position well below
the contact surfaces 8 of the terminals 2 and has an
upper (as seen in Figure 7) surface 90, a single
central opening 30X being formed in each web 32X
~oining the side walls 26 to the barrier wall 28X.
In the open position of the connector lX, the printed
circuit board 92 is inserted into the openings 30X
a~ong an insertion path, in the direction of the
arro~ 93 in Figure 7 until the leading en~ of the
board 92 seats upon the surface 90. The connector lX
is then placed in its closed position so that the
contact portions 8 of the terminals 2 engage printed
conductors 94 on either side of the board 92. The
- 16 -
113t~54`7
connector lX is otherwise constructed-and operates
in the same way as the connector 1 described above.
Parts of the connector lX which are the same as
corresponding parts of the connector 1, bear the
same reference numerals.
Since the barrier wall 28X does not extend
between the contact portions 8, a shim block (not shown)
should be inserted between the two rows of terminals
2 prior to using the tool 80 to insert the portions
20 of the terminals 2 into the holes in the printed
circuit board 88.
The fingers 40 on either side of the housing
could be replaced by single resilient member serving
the same purpose.
The connector 1 may if desired have only a single
row o~ terminals 2, the wall 28 acting as an external
side wall of the housing and only one shroud 66 being
provided. Similarly, in the connector lX, the webs
32X on one side of the cavity 30X may be replaced by
an external side wall of the housing.
- 17 -
