U.S. patent number 3,915,538 [Application Number 05/515,487] was granted by the patent office on 1975-10-28 for zero insertion force connector assembly.
This patent grant is currently assigned to Molex Incorporated. Invention is credited to Arnold A. Case, William D. Gruhn, Jr..
United States Patent |
3,915,538 |
Gruhn, Jr. , et al. |
October 28, 1975 |
Zero insertion force connector assembly
Abstract
A zero insertion force connector assembly including a plug
housing that is movable in a socket housing, each housing having an
array of terminals. As the housings are initially moved together,
the terminals are not in engagement and zero insertion force is
provided. When the housings are subsequently moved toward each
other, the terminals are engaged with each other. Movement of the
housings is effected by an improved means which include a pair of
actuator elements mounted on either side of one housing by an
integral hinge and movable into a latched position so that it
forces the other housing member to a position whereby the
individual pairs of contacts are in a touching relation.
Inventors: |
Gruhn, Jr.; William D.
(Lombard, IL), Case; Arnold A. (Chicago, IL) |
Assignee: |
Molex Incorporated (Lisle,
IL)
|
Family
ID: |
24051569 |
Appl.
No.: |
05/515,487 |
Filed: |
October 17, 1974 |
Current U.S.
Class: |
439/342; 439/862;
439/678 |
Current CPC
Class: |
H05B
3/06 (20130101); H01R 13/28 (20130101); H01R
13/62905 (20130101); H01R 2107/00 (20130101) |
Current International
Class: |
H01R
13/02 (20060101); H01R 13/28 (20060101); H01R
13/193 (20060101); H05B 3/06 (20060101); H01R
013/54 () |
Field of
Search: |
;339/75R,75M,75MP,75P,274 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lake; Roy
Assistant Examiner: Bicks; Mark S.
Attorney, Agent or Firm: Hecht; Louis A.
Claims
We claim:
1. A zero insertion force connector assembly including a first
connector housing, a second connector housing mounted for movement
relative to said first housing between an initial position and a
final position, a plurality of pairs of terminals each pair
including one terminal supported by the first housing and the other
terminal supported by the second housing, the terminals of each
pair being spaced apart when said housings are in the initial
position and moving into engagement with each other when said
housings are moved to the final position, and actuating means
associated between said housings for moving said second housing
from the initial position to the final position, the improvement in
said actuating means comprising:
a cam surface formed on the first housing facing the second
housing;
cam means movable between said cam surface and second housing from
a released position to a latched position, whereby said second
housing is moved from the initial position to the final position;
and
interengaging means formed on said cam surface and cam means for
holding said cam means in the latched position.
2. The assembly of claim 1 wherein said cam means is mounted at the
end of an arm movably mounted on the first housing, movement of the
arm causing said cam means to move from its released position to
its latched position.
3. The assembly of claim 1 wherein said cam means is generally
wedge shaped and said cam surface compliments said cam means.
4. The assembly of claim 1 wherein said interengaging means
includes a protrusion formed on said cam surface and a recess
formed on said cam means adapted to receive said protrusion when
said cam means is in its latched position.
5. A zero insertion force connector assembly including a first
connector housing, a second connector housing mounted for movement
relative to said first housing between an initial position and a
final position, a plurality of pairs of terminals each pair
including one terminal supported by the first housing and the other
terminal supported by the second housing, the terminals of each
pair being spaced apart when said housings are in the initial
position and moving into engagement with each other when said
housings are moved to the final position, and actuating means
associated between said housings for moving said second housing
from the initial position to the final position, the improvement in
said actuating means comprising:
a pair of cam surfaces formed on the first housing facing the
second housing;
a pair of cam means, each associated with one of the cam surfaces
and movable in opposite directions between the respective cam
surfaces and the second housing from a released position to a
latched position, whereby said second housing is moved from the
initial position to the final position; and
interengaging means formed on each cam surface and cam means for
holding each cam means in the latched position.
6. The assembly of claim 5 wherein each cam means is mounted at the
end of an arm movably mounted on the first housing, movement of the
arm causing said cam means to move from its released position to
its latched position.
7. The assembly of claim 5 wherein each cam means is generally
wedge shaped and said cam surface compliments said cam means.
8. The assembly of claim 5 wherein each interengaging means
includes a protrusion formed on each cam surface and a recess
formed on each cam means adapted to receive said protrusions when
said cam means is in its latched position.
9. A zero insertion force connector assembly including a first
connector housing, a second connector housing mounted for movement
relative to said first housing between an initial position and a
final position, a plurality of pairs of terminals each pair
including one terminal supported by the first housing and the other
terminal supported by the second housing, the terminals of each
pair being spaced apart when said housings are in the initial
position and moving into engagement with each other when said
housings are moved to the final position, and actuating means
associated between said housings for moving said second housing
from the initial position to the final position, the improvement in
said actuating means comprising:
said second housing being received and reciprocally movable within
said first housing between said initial and final positions;
said first housing including an interior defined by side walls and
end walls, a pair of cam surfaces formed at one end of the interior
of the first housing extended from an end wall and facing and
spaced from said second housing, a pair of apertures formed in
opposing side walls at opposite ends of the space between the cam
surfaces and the second housing, two actuating elements mounted on
the outside of the first housing side walls, one near each
aperture, each actuating member including an arm pivotally mounted
on the side wall having a cam portion on the free end thereof
adapted to be received through the aperture into the space between
the cam surface and the second housing and is movable in said space
from a released position to a latched position when said arm is
pivoted whereby said second housing is moved away from said cam
surfaces from the initial position to the final position, said
first housing further including interengaging means formed on each
cam surface and cam portion for holding each actuator element in
the latched position.
10. The assembly of claim 9 wherein each cam portion is generally
wedge shaped and said cam surface compliments said cam portion.
11. The assembly of claim 9 wherein each interengaging means
includes a protrusion formed on each cam and a recess formed on
each cam portion adapted to receive said protrusion when said cam
portion is in its latched position.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to electrical connectors, and more
particularly to connector assemblies known as zero insertion force
assemblies.
2. Brief Description of the Prior Art
In the use of the conventional electrical terminals, such as widely
used pin and socket terminals, a frictional force, known as an
insertion force, is encountered when terminals are interconnected.
The forces involved are not objectionable when only one or a few
pairs of such terminals are interconnected. However, when a large
number of interconnections are made in a single operation, for
example in the connecting of wiring harnesses or the like, the
total insertion force becomes undesirably large.
In order to overcome the problem of excessive insertion forces,
so-called zero insertion force connectors have been developed. In
the usual arrangement of such connectors, two connector housings
are moved with respect to one another. Each housing carries a
terminal which is adapted to be adjacent a corresponding terminal
carried in the other housing. Initially, the pairs of terminals of
the two housings are not in contact with one another so that little
or no frictional forces resulting from such engagement need be
overcome. When the housings are moved from the initial position to
a final position, the terminals of each pair are moved into
engagement with one another.
In order to move the housings from the initial position to the
final position, there is ordinarily provided some sort of actuating
means. One example of a suitable actuating means is disclosed in
U.S. application Ser. No. 463,267 which has been assigned to the
assignee of the present application. The actuating means of the
earlier filed application is in the form of a single hinge strap
having a portion which pushes against one of the housings when in a
locked position. While this configuration is satisfactory when
dealing with relatively small forces, it has been found that this
configuration does not offer the positive locking forces necessary
over a long period of time when dealing with larger forces
generated when a large number of terminals are interconnected. This
is due to deformation caused by forces exerted against the
actuating member by the two housings and their respective
terminals.
SUMMARY OF THE INVENTION
It is therefore the principal object of the present invention to
provide a zero insertion force connector assembly having an
improved actuating means that will consistently exert a positive
locking force over long periods of time.
This object is accomplished by one form of the improved actuating
means which provides for a cam surface formed on the first housing
facing the second housing, and cam means movable between the cam
surface and the second housing from a released position to a
latched position whereby the housings are moved from an initial
position to a final position, and interengaging means formed on the
cam surface and cam means for holding the cam means in the latched
position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a zero insertion force connector
assembly constructed in accordance with the present invention;
FIG. 2 is a top view of the assembly of FIG. 1 with the connector
housings in an initial position;
FIG. 3 is a top view of the assembly of FIG. 1 with the connector
housings in a final position;
FIG. 4 is a side view, partially broken away, of the assembly of
FIG. 1 with the housings in an initial position;
FIG. 5 is a fragmentary side view similar to part of FIG. 4 in
illustrating the housings in their final position;
FIG. 6 is a front view of the plug connector housing of the
assembly of FIG. 1;
FIG. 7 is an enlarged detail view of one portion of FIG. 6 showing
one terminal receiving cavity and contact chamber;
FIG. 8 is a sectional view taken generally along the line 8--8 of
FIG. 7;
FIG. 9 is a sectional view taken generally along the line 9--9 of
FIG. 7;
FIG. 10 is a back view of the socket connector housing of the
assembly of FIG. 1;
FIG. 11 is an enlarged detail view showing one terminal receiving
cavity of the housing of FIG. 10, viewed from the front;
FIG. 12 is a sectional view taken generally along the line of
12--12 of FIG. 11;
FIG. 13 is an elevational view of one terminal of the assembly of
FIG. 1, illustrating the terminal before it is engaged with a
conductor;
FIG. 14 is a sectional view taken generally along the line 14--14
of FIG. 13;
FIG. 15 is an end view of the terminal of FIG. 13;
FIG. 16 is a view similar to FIG. 12 illustrating a terminal
mounted in a terminal receiving cavity of the socket connector
housing;
FIG. 17 is a view similar to FIG. 8 illustrating a terminal mounted
in a terminal receiving cavity of the plug connector housing;
FIG. 18 is a fragmentary sectional view taken generally along the
line 18--18 of FIG. 17 and showing two contacts of a terminal pair
when the housings are in the initial position;
FIG. 19 is a view similar to FIG. 18 showing the contacts when the
housings are transversely moved partly to the final position;
and
FIG. 20 is a view similar to FIG. 18 and 19 showing the contacts
when the housings are in the final position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-5 in greater detail, the zero insertion
force connector assembly of the present invention, generally
designated 20, is seen to generally include a pair of connector
housings 22 and 24. In the illustrated embodiment of the invention,
the housings 22 and 24 comprise respectively a plug housing and a
socket housing. It should be understood that other housing
configurations could be provided, and in addition one or both of
the housings may be provided with conventional panel mounting
structure.
Each of the housings 22 and 24 is provided with a plurality of
terminals 26. Although each of the terminals used in the assembly
20 is identical with the others, to facilitate an understanding of
the invention the designation 26P is used to designate a terminal
when mounted in the plug housing 22, and the designation 26S is
used to designate a terminal when mounted in a socket housing 24.
The assembly 20 serves to provide a releasable electrical
connection between one group of electrical conductors 28 connected
to the terminals 26P of housing 22 and a second group of electrical
conductors 30 connected to the terminals 26S of the housing 24.
Referring now to FIGS. 13-15, each terminal 26 is formed, as for
example by a sequence of press operations, from conductive sheet
metal material such a brass or the like. Each terminal 26 includes
an intermediate base portion 32 extending between a conductor
engaging portion 34 and a flat blade contact portion 36. In the
illustrated arrangement, the conductors 28 and 30 comprise
insulation clad wire conductors. Consequently, the conductor
engaging portion 34 of each terminal 26 includes wire crimp
structure in the form of a pair of wire crimping flanges 38 adapted
to be crimped against a conductor wire and a pair of insulation
crimping flanges 40 adapted to be crimped against the insulation of
a wire. It should be understood that the present invention may be
applied to connectors used with conductors other than insulation
clad wires, and the conductor engaging portions 34 may take other
forms, such as, by way of example, solder tails, wire wrap posts,
etc.
In order to assist in guiding and retaining each terminal 26 in
position in the housings 22 or 24 after connection to a wire, the
base portion 32 of the terminal is provided with a pair of wing
members 42 on its opposite sides and with a locking tank 44 struck
from an intermediate region of the base 32. preferably the sides
and end of the blade contact portion 36 are coined in order to
provide for smooth insertion of the terminal 26 into its housing
and to provide for smooth engagement of the blade contacts 36 with
one another.
Proceeding now to a more detailed description of the plug and
socket housings 22 and 24, the housings may be formed as by molding
from a suitable plastic material having electrical insulating
properties. In the preferred embodiment, the plug housing 22 and
the socket housing 24 are each adapted to receive 36 terminals 26
arranged in 4 rows of 9 each. It should be understood that more or
fewer terminals could be provided in any type of array. The
housings 22 and 24 are each provided with an array of cavities 48,
one for receiving each terminal 26. Although the cavities of the
plug 22 and socket 24 are similar, the reference 48P is used to
designate a cavity socket 24.
A cavity 48S of the socket housing 24 is shown in FIGS. 11 and 12,
and a cavity 48P of the plug housing 22 is shown in FIGS. 7-9. Each
cavity includes an enlarged entrance area 50 facing the rear of the
respective housing through which a terminal 26 with a conductor
attached is inserted. The individual entrance areas 50 of the
various cavities 48 are separated in both housings 22 and 24 by a
honeycomb wall structure 52 serving to prevent inadvertent short
circuiting between the conductor engaging portions 34 of adjacent
terminals 26.
In order to capture a terminal 26 within the cavity 48, the
cavities are provided with a neck portion of relatively small cross
sectional area defined between sloping guide surfaces 54 facing
toward the entrance area 50 and a pair of opposed shoulders 56.
Commencing adjacent the sloped surface 54, a pair of opposed guide
slots 58 are provided and a stop surface 60 is disposed within each
of the slots 58. When a terminal 26 is inserted into the cavity 48
as shown in FIGS. 16 and 17, the blade contact portion is guided
into the slots by the sloped surfaces 54. As the terminal is
further inserted, the wing members 42 also enter the slots 58. The
locking tang 44 is resiliently compressed toward the base 32 and
moves through the reduced area neck portion of the cavity. When the
tang clears the shoulders 56, the tang moves outwardly to engage
one shoulder 56 and prevent inadvertent withdrawal of the terminal.
Over insertion is prevented by engagement of the leading edges of
wing members 42 with the shoulders 60. The terminal may be inserted
in either of two positions offset one hundred eighty degrees from
each other. This serves to facilitate the assembly of the
connector.
Upon insertion of a terminal 26 into a cavity 48, the base 32 of
the terminal is captured and held in position between the shoulders
56 and 60. The blade contact portion 36 extends outwardly from the
cavity 48 and is supported by the cavity structure in the nature of
a projecting cantilever beam or spring.
The socket housing 24 includes a front surface 62 onto which the
cavities 48S directly open (FIGS. 11 and 17). Thus, in the case of
the socket housing 24, the blade contacts 36 of the terminals 26S
extend forwardly from the surface 62.
With reference to the plug housing 22, this situation is somewhat
different. As can best be seen in FIGS. 8, 9 and 17, there is
provided a contact chamber 64 at the forward end of each cavity
48P. The individual contact chambers 64 are separated from one
another by means of a honeycomb-like cord wall structure 66. As
appears in FIG. 17, in profile each of the contact chambers 64 is
somewhat in the shape of a modified parallelogram. The front
surface of the plug housing 22 is defined by a forward wall 68
(FIGS. 6-9 and 17) onto which each of the contact chambers 64
opens.
In accordance with the invention, there is provided structure for
guiding the housings 22 and 24 relative to one another as they are
joined together in face-to-face relationship. More specifically,
the plug housing 24 is provided with a series of projections 70
extending to the sides of the housing from adjacent the front
surface 62. The socket 24 is provided with two side walls 72 and
two end walls 73 surrounding the periphery of the forward wall 62
of the socket. The walls 72 and 73 serve to protect the blade
contents 36 extending from the wall 62 prior to joining of the
housings 22 and 24 and also to receive the plug housing 22. In
order to guide the housing relative to one another, the side walls
72 are provided with a group of inwardly opening slots or grooves
74 located to receive the guide projections 70 of the plug housing
22.
Initially, as the housings 22 and 24 are moved toward one another,
one of the projections 70 is received into each of the grooves 74.
Preferably, the projection 70 and groove 74 are located at
irregular positions at the edges of the housings in order to
provide an indexing function by insuring that the housings can be
joined only when in the proper orientation.
The path of relative movement between the housings 22 and 24 is
fixed by the shape of the groove 74. As can be seen in FIGS. 4 and
5, each groove 74 is generally L-shaped. Thus, as the housings are
first moved together, they can only move in a first vertical
direction toward one another as the projections move along the
upright leg of the L. The two housings come fully into engagement
with each other in an initial position wherein the forward wall 68
of the plug housing 22 is substantially in engagement with the
front surface 62 of the socket housing 24. In this position, each
guide projection 70 reaches the base portion of the corresponding
L-shaped groove 74. It is now possible for the two housings 22 and
24 to be moved transversely relative to one another with the
projections 70 moving along the base of the L.
As the housings 22 and 24 are moved transversely at one another,
the blade contact portions 36 of each set of terminals 26P and 26S
are moved into electrical engagement. Referring now to FIG. 18, it
can be seen that when the housings are initially joined, and prior
to being moved transversely, the blade contacts 36 of each set of
terminals are spaced from one another within the corresponding
contact chamber 64. The blade contact portions of each pair include
overlapping end segments which overlay one another. The blade
contact portions 36 are parallel with one another, and are inclined
at an angle relative to the direction of transverse movement of the
housings 22 and 24.
As noted above, the chamber 64 is somewhat in the shape of a
parallelogram in cross section and, for the most part, the blade
contact portions 36 are unsupported as they move into engagement
with one another. However, there is provided a support shoulder 78
located behind the back surface of the blade contact 36 associated
with the terminal 26P. This support shoulder 78 supports the blade
contact 36 only adjacent one edge of the blade, the majority of the
width of the blade being unsupported. The supported edge is that
which is furthest from the other blade contact 36 of the socket
housing terminal 26S.
As the two housings are moved transversely from their initial
position of FIG. 18 toward the final position of FIG. 20, the two
blade contact portions 36 move into engagement with one another as
shown in FIG. 19. Relative to the contact chamber 64, the blade
contact 36 of the terminal 26S moves toward the support shoulder 78
and toward the other blade contact 36. After engagement of the two
contacts 36, some additional transverse housing movement takes
place. During this additional movement, both terminals, in
engagement with one another, twist or pivot about the support
shoulder 78. Thus, the support shoulder 78 acts in the nature of a
fulcrum or pivot. Due to this twisting or torsional movement and to
the resiliency of the metal blade contacts 36, a highly desirable
reliable electrical contact action takes place. Moreover, the need
for exacting tolerances is avoided since this arrangement provides
for a degree of overtravel.
Each of the several blade contacts 36 is disposed at a 45.degree.
angle relative to the direction of transverse housing movement. In
light of the fact that the assembly 20 includes a large number of
interconnections, it is desirable to normalize or cancel out those
forces resulting from engagement of the contacts which are not in
line with the direction of transverse housing movement in order to
avoid a tendency of the housings to bind against one another during
transverse movement. For this reason, two of the four rows of
contacts are located offset 90.degree. from the other two rows.
(FIGS. 6 and 10).
In accordance with the present invention, there is provided a novel
actuating means for bringing about transverse movement of the
housings 22 and 24 relative to one another. More specifically, and
referring now to FIGS. 1-5 and 10, the improved actuating means is
seen to generally include two actuator elements, generally
designated 80, formed on the outside of each side wall 72 of the
socket housing 24. Each actuator element 80 is mounted for pivotal
movement by means of an integral hinge portion 82 of reduced cross
sectional area. Each actuator element 80 is movable from a released
or unlocked position illustrated in FIGS. 2, 4 and 10 to a latched
or locked position illustrated in FIGS. 1 and 5.
Each actuator element 80 is provided with an arm portion 84
extending from the hinge portion 82. A wedge shaped cam portion 86
extends generally perpendicularly and inwardly of the free end of
the arm portion 84. The cam portion 86 of each actuator element 80
is adapted to be received in through a respective aperture 90
formed in each of the side walls 72 of the socket housing 24.
Two cam surfaces 92 are formed on the interior of one of the end
walls 73 of socket housing 24. Cam surfaces 92 face and are spaced
from an end wall 96 of the plug housing 22. Each cam surface 92 is
provided with a protrusion 98 which is adapted to be snap-fitted
into a recess 100 formed in each of the respective cam portions 86
of each actuator element 80.
Looking at FIGS. 2 and 3, the operation of the actuating means is
demonstrated as the plug housing 22 is moved from its initial
position (FIG. 2) to its final position (FIG. 3). As each actuator
element 80 is moved toward its latched or locked position, each cam
portion 86 enters its respective aperture 90 and simultaneously
engages its respective cam surface 92 and the end wall 96 of the
plug housing 22. Further insertion of the cam portion 86 of each
actuator element 80 causes the plug housing 22 to move in the
direction indicated by arrow A in FIG. 2 relative to the socket
housing 24. This occurs because of the contour of the cam surfaces
92. When the actuator elements 80 reach their fully latched or
locked position, protrusion 98 is received in a recess 100 in a
snap-fit fashion to lock the respective actuator or element 80 in
the latched position.
The L-shaped configuration of the grooves 74 provide a bayonet-like
locking action. As long as the actuator elements 80 are latched,
the two housing 22 and 24 cannot be separated by pulling them
apart. Should the plug housing 22 not be fully seated within the
socket housing 24, then each actuator element cannot be closed, and
an indication is provided that the housings have not been properly
assembled. Due to the integral hinging of each actuator element 80
on the side wall 72, the arm portion 84 acts as a lever and
provides a mechanical advantage in effecting transverse movement of
the housings 22 and 24 relative to one another.
As the housings 22 and 24 are moved to their initial position, the
blade portion 46 of each socket housing terminal 26S is received
within one of the contact chambers 64 adjacent to but spaced from
one of the blade portions 36 of one plug housing terminal 26P.
Since the terminals 26P and 26S do not contact one another at this
time, zero insertion force is provided. Each contact set is then
closed as housings 22 and 24 are moved transversely of one another.
The wall structure 66 surrounding each contact chamber serves to
isolate each contact pair from its neighbors.
The configuration of the actuating means as described above is such
that deformation of the actuator element 80 or unlocking thereof
will not occur even after relatively long periods of time. This is
due in large part to the fact that the force exerted by the plug
housing 22 is against a relatively thick cam portion 86. Because of
the interengagement of the protrusion 98 with the recess 100, this
force will not cause the actuator element 80 to pop out into an
unlocked or released position. On the other hand, it is still
possible to manually release or unlock each actuator element 80
when desired.
The actuating means of the present invention can be used in any
socket and plug assembly of the type described regardless of the
specific terminal or contact arrangement involved. The same
positive locking feature will be effective in any
configuration.
* * * * *