U.S. patent number RE32,559 [Application Number 06/933,009] was granted by the patent office on 1987-12-15 for card edge connector locking device.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to James L. Fedder, Attalee S. Taylor.
United States Patent |
RE32,559 |
Fedder , et al. |
December 15, 1987 |
Card edge connector locking device
Abstract
The invention is a locking device for locking circuit cards in
zero-insertion force card edge connectors of the type having a
vertically moving upper housing. More particularly, the locking
device includes two pairs of pivotally mounted arms which are
cammed inwardly from each side of the card. The upper nose-shaped
ends of the arms enter holes in the card so that the card cannot be
removed without actuating the camming mechanism.
Inventors: |
Fedder; James L. (Harrisburg,
PA), Taylor; Attalee S. (Palmyra, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
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Family
ID: |
23801495 |
Appl.
No.: |
06/933,009 |
Filed: |
November 20, 1986 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
453653 |
Dec 27, 1982 |
04487468 |
Dec 11, 1984 |
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Current U.S.
Class: |
439/325;
439/630 |
Current CPC
Class: |
H01R
12/7005 (20130101); H05K 7/1405 (20130101); H01R
13/639 (20130101); H01R 12/88 (20130101) |
Current International
Class: |
H05K
7/14 (20060101); H01R 13/639 (20060101); H01R
013/639 () |
Field of
Search: |
;339/75MP,176MP
;439/325-328,629-637 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McQuade; John
Attorney, Agent or Firm: Osborne; Allan B.
Claims
We claim:
1. A locking device for use with card edge connectors of the type
having a lower housing, a vertically moving upper housing, a card
receiving slot and cavities normal to and opening into the slot,
said locking device comprising:
a. a pair of identical, elongated arms, pivotally mounted at their
lower ends to the lower housing with the pivotal motion being
normal to the card receiving slot, said arms extending upwardly
into the cavities in the upper housing and having on their upper
ends a nose which faces towards the slot; and
b. a first follower on one side of each arm and cooperative cam
means on the cavity wall adjacent thereto to pivot the arms in
towards the slot as the upper housing moves upwardly whereupon the
noses enter holes in a card which may be in the slot to lock the
card therein, and a second follower on the other side of each arm
and cooperative cam means on the cavity wall adjacent thereto to
pivot the arms out from the slot as the upper housing moves
downwardly whereupon the noses are withdrawn from the holes to
unlock the card.
2. The locking device of claim 1 wherein the first follower
includes a downwardly facing, arcuate shoulder and the cooperating
cam means on the cavity wall adjacent thereto includes a slanting
but generally horizontal surface against which the arcuate shoulder
follows to rapidly pivot the arm inwardly as the upper housing
begins to move upwardly.
3. The locking device of claim 2 wherein the first follower further
includes an edge wall extending upwardly from the arcuate shoulder
and the cooperating means further include a vertical wall extending
downwardly from the generally horizontal surface and against which
the edge wall abutts to hold the arm inwardly towards the slot.
4. The locking device of claim 1 wherein the second follower
includes an upwardly facing, arcuate shoulder and the cooperating
cam means on the cavity wall adjacent thereto includes a downwardly
facing, slanting but generally horizontal surface against which the
arcuate shoulder follows to rapidly pivot the arm away from the
slot as the upper housing nears the end of a downward travel.
5. The locking device of claim 4 wherein the second follower
further includes an edge wall extending downwardly from the arcuate
shoulder and the cooperating means further includes a vertical wall
extending downwardly from the generally horizontal surface with the
edge wall bearing against the vertical wall to hold the arm in
towards the slot for substantially most of the downward travel of
the upper housing. .Iadd.
6. A locking device for use with card edge connectors of the type
having a lower housing, a vertically moving upper housing, a card
receiving slot and cavities normal to and opening into the slot,
said locking device comprising:
a. a pair of identical, elongated arms pivotally disposed in the
lower housing with the pivotal motion being normal to the card
receiving slot, said arms extending upwardly into the upper housing
and having on their upper ends a nose which faces towards the slot;
and
b. a first follower on one side of each arm and cooperative cam
means on the cavity wall adjacent thereto to pivot the arms in
towards the slot as the upper housing moves upwardly whereupon the
noses enter holes in a card which may be in the slot to lock the
card therein, and a second follower on the other side of each arm
and cooperative cam means on the cavity wall adjacent thereto to
pivot the arms out from the slot as the upper housing moves
downwardly whereupon the noses are withdrawn from the holes to
unlock the card. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention disclosed herein relates to devices for removably
locking printed circuit cards in card edge connectors. More
particularly, the invention relates to zero insertion force card
edge connectors having sliding cam members to cam the contact
elements against the traces on the card and simultaneously to move
the locking arms into holes in the card.
2. Prior Art
The invention disclosed herein is a novel improvement and a
departure from at least the following:
______________________________________ U.S. Pat. No. Patentee
Class/Subclass ______________________________________ 3,573,706
Haberlen 339/17 3,970,353 Kaufman 339/75 MP 4,017,138 Evans 339/75
MP ______________________________________
Haberlen discloses a flat H-shaped leaf spring with the free ends
of the upwardly extending legs having inwardly facing noses. The
spring is positioned in the card edge connector so that a card
enters in between the legs where upon the noses removably enter a
hole in the card to retain it in the connector.
Kaufman discloses substantially the same type of locking device
with differences being primarily in the way the device is
positioned and retained in the connector. Both the Haberlen and
Kaufman devices are shown as being used with high insertion force
card edge connectors.
Evans discloses a locking device consisting of upright latch arms
at each end of a connector having a vertically moving member which
cams the contact elements into engagement with the traces on the
card. The latch arms, each having facing hooks at the free ends,
are cammed upwardly as the moving member is pushed down so that the
hooks move in over the top edge of the card to retain it in the
connector. Additionally, release arms are provided which lock the
latch arms in the latched position and, upon being pushed inwardly,
release the latch arms so that the card may be withdrawn.
SUMMARY OF THE INVENTION
The invention disclosed herein comprises a pair of locking arms
pivotally mounted to the lower housing of a zero insertion force
card edge connector. The free ends of the arms extend upwardly into
the upper housing and are cammed in and out of the card slot as the
upper housing is moved up and down. Nose-shaped free ends on the
arms enter holes in the card so that the card cannot be withdrawn
from the connector without moving the arms back out of the
holes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view showing a zero insertion force
connector into which the locking device of the present invention is
incorporated. The drawing shows, in phantom, one pair of locking
arms of the locking device;
FIG. 2 is a cross-sectional view looking into the connector of FIG.
1 from an end and shows the locking arms cammed out of the card
slot; and
FIG. 3 is the same view as FIG. 2 but taken after the locking arms
have been cammed into holes in a circuit card positioned in the
card slot.
DESCRIPTION OF THE INVENTION
The invention disclosed herein is a locking device for removably
locking circuit cards in a card edge connector. The locking device
utilizes the mechanism of a zero insertion force connector 10 shown
in the several drawings. This connector has a lower housing 12, a
vertically moving upper housing 14, camming mechanism 16 which,
moving longitudinally, raises or lowers the upper housing through a
series of ramps (not shown). Further, a plurality of contact
elements (not shown) are positioned in the connector. Upper beams
(not shown) on the elements extend upwardly into cavities 18 in the
upper housing and as the upper housing moves up, the beams are
cammed in towards card slot 20 to bear against traces (not shown)
on a card which may be positioned therein.
Under normal conditions, the beams exert enough pressure on the
card so that it does not move. This is not true under high
vibrational forces and the like which can cause the card to shift
up and also move lengthwise in the slot. The latter motion must be
guarded against to prevent short circuits and mismatch.
Accordingly, the locking device of the present invention locks the
card in the connector and prevents any motion whatsoever. Further,
the cards cannot be withdrawn without taking a positive step; i.e.,
actuating camming mechanism 16.
The locking device includes two pairs of identical, elongated arms
22 with one pair positioned adjacent each end of card slot 20. FIG.
1 shows one pair of arms 22 in phantom.
With reference to both FIGS. 1 and 2, each arm is pivotally mounted
at its lower end 24 in lower housing 12 with the pivoting direction
being towards and away from the card slot; i.e., normal to the
longitudinal axis of connector 10. The mounting means may be pins
26 or the like.
Arms 20 extend upwardly into cavities 28 in the upper housing.
Facing cavities are horizontally offset as shown in FIG. 1. The
upper ends 30 of the arms include a nose 32 located on the inside
edge 34 so that it projects in towards card slot 20.
Each arm includes a first follower 36 on side 38 and a second
follower 40 on opposite side 42. With the arms being identical, the
first follower 36 and side 38 on one arm; e.g., the left-hand arm
in FIG. 2, faces in the same direction as the second follower and
side 42 on the other, facing arm; e.g., the right-hand arm in FIG.
2. The followers are located just below upper ends 30 of the arms
so that they may be actuated by cam means located on sidewalls 44
of cavities 28 in upper housing 14.
First follower 36 includes a downwardly facing, arcuate shoulder 46
and merging therewith, outwardly facing edge wall 48. First
follower 36 rides along first cam surface 50 that includes a
slanting but generally horizontal surface 52 and below that, a
vertical wall 54.
Second follower 40 includes an upwardly facing arcuate shoulder 56.
This surface rides along U-shaped second cam surface 58, the bight
60 of which faces downwardly. As shown in FIGS. 2 and 3, the bight
is slanting but generally horizontal.
To reiterate, each arm has a first follower 36 on one side and a
second follower on the opposite side. Being identical, arms in
opposing (but offset) cavities will offer different sides to a
viewer looking into the connector from an end; e.g., FIGS. 2 and 3.
Similarly, cavity walls on one side of the arms carry different cam
surfaces.
The operation of the locking device of the present invention will
now be explained.
In FIG. 2, connector 10 is in the open position; i.e., the upper
beams of the contact elements (not shown) are back in their
cavities in the upper housing so that circuit card 62 was inserted
into slot 20 without force. Locking arms 22 are also retracted in
their cavities 28.
To close connector 10, camming mechanism 16 (FIG. 1) is moved
longitudinally. Upper housing 14 is thereby moved vertically
upwardly. Cam surfaces (not shown) in the contact element cavities
18 cam the upper beams in against traces on card 62.
Simultaneously, locking arms 22 are pivoted inwardly by first
followers 36 riding against the upwardly moving first cam surfaces
50. The inwardly directed motion is brought about by arcuate
shaped, downwardly facing shoulder 46 riding on slanting surface
52. Since the angle that surface makes relative to the horizontal
is small, this inward motion is quite rapid. During this motion,
noses 32 enter holes 64 in card 62. Since the cavities 28 and the
arms are offset, the noses do not meet but rather slide by one
another. As the upper housing continues to move, vertical wall 54
of cam surfaces 50 engages edge walls 48 of the first followers and
holds the arms in the locking position shown in FIG. 3.
To open connector 10, camming mechanism is pushed back, causing
upper housing 14 to move downwardly to the FIG. 2 position. As it
moves down, the upper beams on the contact elements move away from
the card as do locking arms 22 by means of second followers 40
riding along second cam surfaces 58. Second followers 40, riding up
one side of the U-shaped cam surface 58, enters and travels along
bight 60. The arms are thus pulled back and the noses retracted
from holes 64. Note that the arms are held in towards the slot for
substantially most of the downward travel and only near the end are
the arms rapidly pulled back upon the arcuate shoulder 58
encountering and following bight 60. The card may be freely
withdrawn from the slot.
One of the advantages of this invention is that if for some reason
the connector is closed without a card in the slot, and then one
tries to insert a card, it will hit the upper ends of the arms and
not the upper beams which would, of course, damage them, probably
beyond repair.
The foregoing detailed description has been given for clearness of
understanding only, and no unnecessary limitations should be
understood therefrom, as some modifications will be obvious to
those skilled in the art.
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