U.S. patent number 3,767,974 [Application Number 05/214,624] was granted by the patent office on 1973-10-23 for insertion and extraction lever for printed circuit cards.
This patent grant is currently assigned to Cogar Corporation. Invention is credited to Charles Edward Card, Jr., Daniel Joseph Donovan, Jr..
United States Patent |
3,767,974 |
Donovan, Jr. , et
al. |
October 23, 1973 |
INSERTION AND EXTRACTION LEVER FOR PRINTED CIRCUIT CARDS
Abstract
A lever for aiding in inserting printed circuit cards into and
extracting them from mating connectors mounted in a multiple card
guiding arrangement. The cards ride in individual slots in a
multiple card cage, and during insertion they can be guided freely
until the card's output conductors initially confront the receiving
connector block at the rear of the cage. At this point, cylindrical
bosses on corresponding upper and lower levers are positioned to
contact a reinforced edge of the card, with pivoting action by the
lever driving the card into the cage and urging the card's
conductors into their mating connectors. Rotation of the levers in
the opposite direction brings another cylindircal boss on each
lever into contact with an inner surface of the card's reinforced
edge, extracting the card conductors from the connector block and
permitting free-sliding removal of the card from the cage.
Inventors: |
Donovan, Jr.; Daniel Joseph
(Hopewell Junction, NY), Card, Jr.; Charles Edward
(Philmont, NY) |
Assignee: |
Cogar Corporation (Wappinger
Falls, NY)
|
Family
ID: |
22799812 |
Appl.
No.: |
05/214,624 |
Filed: |
January 3, 1972 |
Current U.S.
Class: |
361/798; 439/64;
439/327; 439/157; 361/725; 200/292; 439/153; 361/754 |
Current CPC
Class: |
H05K
7/1409 (20130101) |
Current International
Class: |
H05K
7/14 (20060101); H05k 005/00 () |
Field of
Search: |
;317/11DH,117,118
;200/166PC ;339/17L,17LC,17LM,17M,17N |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Tolin; Gerald P.
Claims
We claim:
1. Apparatus for controlling the positioning of a plurality of
circuit cards with respect to a card guiding system comprising a
plurality of cards, a housing for receiving said cards which are
removably mounted in said housing, a pair of control lever means
for each of said cards mounted on said housing for inserting each
of said cards into and extracting it from said housing, each of
said cards including a control edge for transmitting to each of
said cards insertion and extraction forces applied by said pair of
control lever means.
2. Apparatus in accordance with claim 2 wherein said housing
includes a plurality of guide slots for receiving said cards, and
wherein said slots define a limit stop for said insertion of said
cards.
3. Apparatus in accordance with claim 2 wherein said control edge
of each of said cards includes at least one arm gripping each of
said cards, said arm having means cooperating with said limit stop
to define the final insertion depth of each of said cards within
said housing.
4. Apparatus in accordance with claim 3 wherein said cooperating
means includes a ridge extending beyond the dimensions of each of
said cards, said ridge coming into contact with said limit stop at
said final insertion depth for each of said cards.
5. Apparatus in accordance with claim 4 wherein said housing
includes a plurality of connector blocks mounted on a rear wall
thereof, each of said cards includes a plurality of conductive
members received within said connector blocks, and wherein said
conductive members are received with said connector blocks at said
final insertion position of each of said cards.
6. Apparatus in accordance with claim 1 wherein said pair of
control lever means includes a first boss for applying said
insertion force to each of said cards and a second boss for
applying said extraction force to each of said cards.
7. Apparatus in accordance with claim 6 wherein said housing
includes an outwardly projecting mounting finger carrying said pair
of control lever means for rotational movement, said finger having
a transverse bore, and said pair of control lever means including a
bifurcated mounting portion having at least one pivoting ear
received within said bore of said finger.
8. Apparatus in accordance with claim 7 wherein said finger
includes a forward tapered region accommodated within and to spread
said bifurcated mounting portion of said pair of control lever
means, said spreading terminating when said pivoting ear mates with
said bore of said finger, thereby defining the pivoting arc of said
pair of control lever means.
9. Apparatus in accordance with claim 6 wherein said housing
includes means mounting said part of control lever means for
rotation toward and away from said housing, and wherein said first
boss contacts said control edge of each of said cards during
extraction of each of said cards from said housing.
10. Apparatus in accordance with claim 9 wherein said first and
second bosses are substantially cylindrical in shape.
11. Apparatus in accordance with claim 9 wherein each of said cards
includes a plurality of conductive elements along a rear edge
thereof and said housing includes a plurality of connector blocks
for receiving said conductive elements of each of said cards and at
least one channel for guiding each of said cards toward said
connector blocks, and wherein each of said cards is inserted into
said channel and rides freely therein until said rear edge is in
confronting relationship with said connector blocks, the rotation
of said pair of control lever means toward said housing causing
said first boss to force said conductive elements into said
connector blocks.
12. Apparatus in accordance with claim 11 wherein the rotation of
said control lever means away from said housing causes said second
boss to contact said control edge to withdraw said conductive
elements from said connector blocks, to thereby reposition each of
said cards for free riding within said channel.
13. Apparatus in accordance with claim 11 wherein each of said
cards further includes retaining means for cooperating with said
pair of control lever means for positively urging each of said
cards into its insertion position, said retaining means including
an outwardly projecting tab having a pair of gripping wings, and
said pair of control lever means includes a retention slot in the
body thereof having a pair of side flanges, said control lever
means adapted to be rotated further toward said housing after said
conductive elements have been received within said connector blocks
to cause said side flanges of said slot to pass over said gripping
wings to establish a retention position for each of said cards.
Description
This invention relates to equipment-handling apparatus, and in
particular, to a device for controlling the loading and unloading
of circuit cards into the out of card-connecting housings.
The development of high speed electronics in recent years has been
continuing at ever-increasing rates. Together with that
development, the applications of integrated circuitry for use in
such electronic circuits have also advanced rapidly. Integrated
circuits, such as miniaturized semiconductor "chips" and wafers,
are generally mounted together on some common board or card for
connection to other electronic apparatus. Thus, typical circuitry
element in systems utilizing integrated circuits would be a module
having numerous semiconductor components (e.g., flip-flops)
therein. Output leads are connected to these components and act as
external connectors from each module. The modules are generally
mounted on rigid printed circuit cards or boards which themselves
have wired interconnections -- each card may carry many modules and
the output conductors or tabs at the edges of the cards are
arranged to be coupled to connector blocks fixed to machine frames
(e.g., of a memory unit). In this manner, each card may carry
hundreds of thousands or even millions of bits of information.
It is also known to mount several cards together in a common
housing to provide even greater memory or programming capacity. One
arrangement along these lines is to mount cards side by side in a
cage-type unit, with each card having its own mounting position and
female connecting blocks. Because of the critical importance of
proper mounting, it is essential that the cards be aligned
precisely during mounting -- this also serves to minimize the risk
of card mutilation and ensures that neither the card conductors nor
the connector blocks are damaged in loading or unloading the cards.
These several problems, while having been generally recognized
heretofore, have not been adequately solved by the prior art.
Thus, prior art systems have often ignored the problem of
facilitating multiple mounting of cards. In prior art arrangements,
circuit cards are often manually forced into their respective
connector blocks. This technique is unsatisfactory for several
reasons, including the lack of control over both the insertion and
extraction steps, and the real possibility of damage being caused
to either the cards or the connector blocks because of the use of
excessive force. This manual approach, which is also time
consuming, too frequently leads to binding or even breaking of the
cards.
One prior art attempt at alleviating these problems has been to
employ small pivotable tabs on each card. These tabs are designed
to engage a flange on the card cage and to pull the card into the
cage and to eject it therefrom when desired. However, these tabs
were wholly inadequate because they still failed to give the
operator much control over the insertion or extraction steps. For
instances, with more concentrated cards, there may be many output
conductor tabs and a corresponding increase in the number of
connectors. This may lead to the need for greater force to be
applied for insertion and extraction, and the small pivotable tabs
on each card could not furnish sufficient leverage or force to
properly perform both the insertion and extraction steps. Moreover,
by mounting the tabs on the cards, additional bulk was created for
the cards which made ordinary handling thereof more difficult.
It is therefore an object of this invention to obviate one or more
of the aforesaid difficulties.
It is a further object of this invention to provide a more
convenient technique for controlling the positioning of electronic
circuit cards in a card mounting system.
It is also an object of this invention to facilitate the insertion
of circuit cards into and their extraction from a multiple card
guiding system.
It is still another object of this invention to arrange for the
accurate connection of elecontric circuit cards to connectors in
electronic apparatus.
Additional objects and advantages of this invention will become
apparent when considered in conjunction with one particular
illustrative embodiment of the invention, wherein one or more
circuit cards are introduced into a multiple card guiding
arrangement so that contact can be made between the conductive tabs
on the card and the stationary connector blocks on the frame of a
memory unit or other similar piece of apparatus. In one embodiment,
the card guiding system takes the form of a cage having a plurality
of parallel slots for receiving the circuit cards. The initial
insertion of cards into the cage is done manually, with the card
itself being inserted in aligned upper and lower slots or channels.
As the card is inserted further into the cage, it reaches the point
where contact is made between a reinforced edge or stiffener on the
outer vertical edge of the card and a boss on the control lever.
This stiffener is provided to receive pressure from the lever of
the invention and to transmit that pressure to the card to complete
the insertion process.
Specifically, when the card reaches its initial contact position
during insertion, the card stiffener comes into contact with a
first substantially cylindrical boss on corresponding upper and
lower control levers or control lever means. These levers are
mounted on tapered fingers which project outward from the cage, and
which are provided with recessed holes to receive pivoting ears on
the lever. When the levers are mounted with their pivoting ears in
the recesses of the tapered cage fingers, there is sufficient drag
in the pivotal movement of the levers to overcome any gravity
forces (e.g., to permit the lever to remain stationary once it
occupies either an upper, intermediate, or lower position).
When contact has been established between the card stiffener (at
upper and lower points) and the first boss on corresponding upper
and lower levers, the rear metallized conductors on the card are in
confronting relationship with the corresponding connector blocks at
the rear of the cage. Thus, the invention insures that the initial
contact between the card and the control lever will occur just
prior to actual contact between the metallized conductors on the
card and the connector block. This prevents any improper insertion
of the card into the connectors and also permits the levers of the
invention to maintain complete control over the insertion and
extraction steps.
Thereafter, each of the upper and lower levers are rotated about
their respective pivoting ears and toward the cage unit. After a
brief rotation, a second boss on each of the levers comes into
contact with the card stiffener. As rotational force continues to
be applied to the levers by an operator, the second cylindrical
boss bears against the card stiffener and drives it firmly towards
the rear of the cage. The metallized conductors on the card are
thereby inserted into the female connector blocks at the rear of
the cage, with insertion being complete when the levers have moved
from their horizontal position (the initial contact point) to a
substantially vertical position. In this latter position, the
second cylindrical boss continues to be in engagement with the card
stiffener, and helps to maintain the card in the inserted
position.
The card stiffener is also provided with upper and lower stops,
formed at the junction at the card itself with the stiffener. The
stop is a blunt edge of the stiffener element which projects
inwardly towards the card cage and which rides above the card on
its upper edge and below the card on its lower edge. As the
insertion process takes place, the stop comes into contact with the
base of the respective upper and lower guiding channels to limit
the insertion depth of the card into the cage. The actual depth of
insertion of the card conductors into the mating connectors is
thereby limited by the dimensional relationship of the card
stiffener stop and the depth of the card guidance channel, thereby
preventing the improper application of excessive forces on the
connector block.
After the final insertion position is obtained, with the control
lever substantially vertical and the card stiffener stop in contact
with the guide channels, the lever is then moved slightly further
in the same rotational direction as it has been during insertion.
This brings a slot in the lever handle over corresponding upper and
lower retention snaps projecting outwardly (i.e., away from the
cage) from the card stiffener. These snaps have a base portion and
a slightly enlarged outer portion, for example in the form of
sidewise projecting wings or tabs. The slots in the levers are
provided with corresponding shoulders on either side such that the
further depression of the lever over the snap causes the snap wings
to be forced past the side ledges of the slot. This retains the
lever in pressure engagement with the card stiffener, and acts as a
clamp for the entire system to avoid any problems associated with
possible card movement or vibrational forces.
The extraction process commences with the removal of the lever from
the retention snap. After the slot has been disengaged from the
snap, pivotal lever motion is continued until an extraction boss at
one end of each lever comes in contact with an inner edge of the
card stiffener. This applies outwardly directed forces against the
card as the levers are rotated. As lever motion continues, the card
is withdrawn from the connector blocks and is partially extracted
from the card cage itself. Thereafter, the card, which is now
riding freely in the guiding channels, can be easily withdrawn by
the attendant.
It is therfore a feature of an embodiment of this invention that a
lever is mounted on a card cage and is pivotable with respect to a
circuit card to urge the card into proper contact with a stationary
connector block and to extract it therefrom.
It is also a feature of an embodiment of this invention that an
insertion and extraction lever is provided with a pair of bosses,
one of which transfers lever force to the circuit card during
insertion into a housing and the other of which transfers such
force to the card during extraction from the housing.
It is a further feature of an embodiment of this invention that a
combined insertion and extraction lever for use in a circuit card
mounting sytem includes a slot for receiving therein a projecting
tab on the card to positively retain the card in position after
insertion.
Additional objects, features and advantages of the invention will
become apparent when considered in conjunction with a presently
preferred but nonetheless illustrative embodiment of the invention
explained in the following detailed description and as shown in the
accompanying drawing, wherein:
FIG. 1 is a perspective view of a multiple card mounting system
comprising a card cage, and illustrating a specimen circuit card
partially inserted into the cage, and other cards in the fully
inserted condition;
FIG. 2 is a side view of the control lever of the invention;
FIG. 3 is a front edge view of the lever;
FIG. 4 is a cross-sectional view through the retention slot of the
lever, taken along the lines 4--4 of FIG. 3, in the direction of
the arrows;
FIG. 5 is a fragmentary sectional view of the upper portion of the
lever, taken along the lines 5--5 of FIG. 3 in the direction of the
arrows;
FIG. 6 is a side view of the cage, illustrating a circuit card
having been inserted up to the point of initial contact between the
card stiffener and the upper and lower levers;
FIG. 7 is a fragmentary showing of the cage and card during the
insertion process showing only the upper lever and its direction of
rotation during insertion;
FIG. 8 is a fragmentary showing of the cage with the card having
been fully inserted, the lever being in the substantially vertical
position;
FIG. 9 is a fragmentary showing of the cage and card stiffener,
partially broken away to reveral the contact between the card stop
on the stiffener and the cage guiding channel, and also showing the
lever slot having been engaged by the retention slot;
FIG. 10 is a fragmentray view of the retention snap and lever slot
in engaging relationship, taken from the perspective of line 10--10
of FIG. 9 in the direction of the arrows; and
FIG. 11 is a fragmentary showing of the cage and card, with the
control lever being pivoted in the direction of the arrow for
extraction of the card from the cage.
The multiple card guiding system 20 of the invention as illustrated
in perspective in FIG. 1 includes a cage having side panels 22
which are rigidly fixed to a rear frame or connector board 24. A
plurality of connector blocks 26 is mounted on board 24, with an
additional plurality of blocks 26 being located between side plates
22 and in line to receive the printed circuit cards upon their
insertion. A series of parallel upper and lower guide channels 28
project outward from the rear of board 24 to define the insertion
and extraction paths of the printed circuit cards.
A typical printed circuit card 34 is illustrated as being partially
inserted into (or extracted from) the cage system 20, with
insertion and extraction being controlled by levers 46 which are
fixed to the cage by being mounted over fingers 32 which themselves
project outward from transverse cage bar 30. The printed circuit
card 34 illustrated in FIG. 1 includes active electronic portion 36
which has on one side a plurality of semi-conductor modules 38 and
on the other a plurality of soldered connections 40 which project
through the card from module 38, making contact with various
internally wired connectors. The outer edge of card 34 is defined
by reinforced stiffener member 42 (which is generally of one-piece
molded construction) which is permanently attached to active card
portion 36. Stiffener 42 functions to receive the bearing forces
from lever 46 during the insertion and extraction steps and
transfers the forces to card portion 36 without damaging that
portion. The card is provided with upper and lower projecting tabs
42a which actually receive the principal thrust of the control
levers during insertion and extraction. Also formed as part of
stiffener 42 are corresponding upper and lower retention snaps 44
which are adapted to fit within slot 52 on levers 46 to firmly
position cards 34 within the cage system 20 after insertion has
been completed.
Considering FIG. 1 along with FIGS. 2-5, it will be appreciated
that lever 46 includes a first outer insertion boss 48 and a second
inner extraction boss 50, as well as through slot 52 for the
retention of cards 34 in cage 20 after insertion has been
completed. Each of levers 46 is provided with a pair of inwardly
facing ears 54 at the upper end of the lever as shown in FIGS. 2
and 3. These ears are adapted to occupy through holes 32a in
tapered fingers 32. The fingers 32 are provided with a lead-in
angle or taper, such that the upper side branches 53 of levers 46
are spread apart (during mounting of the levers) until ears 54
enter the finger holes 32a. Thereafter, levers 46 pivot relatively
freely about their mounting position within finger holes 32a,
although the system is designed to have some "drag" upon the levers
to permit any particular rotational position of levers 46 to be
maintained against gravity. Considering FIGS. 3 and 4, the
configuration of slot 52 includes an outer portion and an inner
portion of reduced width adapted to fit over retention snap 44. In
particular, slot 52 is provided with oppositely confronting
shoulders 52a which can be forced over outwardly projecting wings
44a on retention snaps 44 to affirmatively hold cards 44 in
position after the insertion process has been completed. This
retention arrangement is illustrated in FIGS. 9 and 10 and will be
described in greater detail below.
THE INSERTION STEP
The insertion of a circuit card 34 is commenced by placing the
upper and lower edges of active card portion 36 in corresponding
upper and lower guide slots 28a within card mounting system or cage
20 (see FIG. 1). The slot 28a is sufficiently wide to permit free
riding of card portion 36 therein, and the card is moved towards
the rear of cage 20 by an attendant until the position illustrated
in FIG. 6 is attained. At this point, levers 46 are in
substantially horizontal orientation, such that inner bosses 50 (to
be used primarily for extraction as described below) of both upper
and lower levers are contacted by the inner edges of upper and
lower projecting tabs 42a of card stiffener 42. At this point, it
will also be appreciated that the rear edge 35 of card 34 (which
carries the conductive tabs coupled to all the soldered connections
on the card) is confronting but is not actually contacting the
connector block 26 mounted on supporting board or frame 24. Thus,
the maximum insertion depth of card 34 with levers 46 in the
horizontal or open position is with rear card edge 35 not quite
making contact with connector blocks 26. This ensures that no
improper manual and uncontrolled insertion of the card will take
place.
Once card stiffener tabs 42a make contact with bosses 50 as
illustrated in FIG. 6, levers 46 are pivoted about their respective
ears 54 as shown (for the upper lever only) in FIG. 7 (see
direction of arrow). This rotation brings insertion boss 48 into
contact with stiffener 42 and applies a force vector substantially
perpendicular to the stiffener edge from both the upper and lower
contact points between lever 46 and stiffener 42. Continued
application of rotational pressure (e.g., by an operator's
downwardly and inwardly pressing upper lever handle 47) urges card
34 further within cage 20. In particular, rear conductive ede 35 of
card 34 enters mating connector block 26 and makes electrical
contact with the connectors therein, with the card and lever
assuming the positions illustrated in FIG. 8. At this point, lever
46 is substantially vertical, and boss 48 is in bearing contact
with card stiffener 42, although it is not forcing card 34 any
further into the cage.
THE RETENTION ARRANGEMENT
As also shown in FIG. 8, retention snap 44 has entered within slot
52 of lever 46. At this point, however, sidewise projecting tabs or
wings 44a of retention snaps 44 have not passed flanges 52a within
slots 52. Accordingly, lever 46 is still capable of being withdrawn
upward by an operator, and correspondingly, card 34 is not
positively fixed in place within cage 20. Thus, it is conceivable
that extraneous forces (e.g., vibration or improper jostling of the
card) could result in the cards being withdrawn slightly from the
cage, thereby breaking some contacts between rear conductive edge
35 and connector blocks 26.
In order to avoid this problem, levers 46 are forced past the
position illustrated in FIG. 8 to that shown in FIG. 9. Continued
inward rotational force is applied to actuating handle 47, and
insertion boss 48 transfers this force to the card via stiffener
42. Card 34 cannot, however, be inserted any further within cage 20
because of a stop arrangement between stiffener 42 and cage guiding
channel 28. In particular, stiffener 42 is provided with an
inwardly projecting arm 42b which, at its innner edge 42c, is
elevated above active card portion 36. Edge 42c of stiffener
thereby acts as a stop limiting the further insertion of card 34
when edge 42c comes into contact with guiding channel 28 as shown
in FIG. 9. The dimensions of guiding channel 28 are such that at
the point of limiting, rear conductive edge 35 of card 34 is
appropriately i serted within connector blocks 26 without being
forced to the furthest rear edge of those blocks.
Accordingly, when further rotational forces are applied to levers
46 as previously mentioned, the bearing of boss 48 against
stiffener 42 does not insert card 34 within cage system 20 any
further. However, by applying such additional force at handle 47,
wings 44a of retention snaps 44 overcome the resistance offered by
flanges 52a within lever slot 52 and snap past these flanges to
occupy the position shown in FIG. 10. At this point, therefore,
lever 46 is retained at an angle slightly inward from the vertical
(see FIG. 9) and forcibly retains card 34 in its fixed inserted
position to minimize any possible effects of vibration or other
extraneous forces. This retention position will be maintained for
so long as lever slot 52 has its inwardly facing flanges 52a past
wings 44a of retention snaps 44.
THE EXTRACTION STEP
The extraction process is commenced by disengaging the retention
slot from the wings of the retention snaps. This is done by an
operator applying outward pivotal force to levers 46 at handles 47.
Flanges 52a within slot 52 thereby move outward past wings 44a of
retention snaps 44 and in essence, lever 46 reassumes the position
illustrated in FIG. 8.
Referring to FIG. 11, movement of lever 46 is then continued in the
direction indicated by the arrow until extraction boss 50 comes in
contact with an inner surface of stiffener tab 42a. Continued
rotation of lever 46 applies substantially horizontal and outwardly
directed forces to card stiffener 42. These forces are sufficient
to overcome the gripping relationship between rear conductive edge
35 of card 34 and the connectors within mating connector blocks 26
at the rear of the cage 20. Rotational movement is then continued
unitl levers 46 are essentially in the position illustrated in FIG.
6, namely with extraction bosses 50 in contact with the inner edges
of tabs 42a of stiffener 42. However, at this point, levers 46 have
reached the maximum rotational position because of contact between
bosses 50 and fingers 32. Cards 34 are now capable of freely riding
within guide slots 28a and an operator can simply withdraw the
card, levers 46 having overcome the principal resisting force which
had been the mating relationship between rear conductive edge 35
and connector block 26.
It is to be understood that the above-described embodiments are
merely illustrative of the application of the principles of this
invention. Numerous variations may be devised by those skilled in
the art without departing from the spirit or scope of the
invention.
In order to permit variations in tolerance which naturally occur in
the fabrication of the parts, the lever is preferably made out of
thermal plastic, such as manufactured by General Electric under the
tradename LEXAN, which plastic material permits the lever to act in
the manner of a spring thereby significantly improving the
retention characteristics of the lever.
* * * * *