U.S. patent number 3,683,317 [Application Number 05/056,298] was granted by the patent office on 1972-08-08 for minimal insertion force connector.
This patent grant is currently assigned to Cambridge Thermionic Corporation. Invention is credited to William B. Walkup.
United States Patent |
3,683,317 |
|
August 8, 1972 |
MINIMAL INSERTION FORCE CONNECTOR
Abstract
An electrical connector of the type receiving a male component
lead is characterized by imposition of extremely small or no
insertion forces on the male lead in order to make electrical
connection. An elastically deformable contact strip forms at least
one side of a cavity, and means are provided for deforming the
contact strip in a lengthwise direction. When the contact strip is
in its relaxed state, the male lead can be inserted freely in the
cavity alongside the strip without significant insertion force. The
contact strip has a curved portion with a contact area facing the
inserted male lead, and a compressible portion connected at one end
to the curved contact portion and being substantially fixed with
respect to the cavity at the other end. As the contact strip is
deformed lengthwise, the contact area tends to expand across the
cavity to exert a contact force against the male lead, and the
compressible portion shrinks in its lengthwise dimension, thereby
wiping the contact area along the male lead for reliable
film-removing electrical contact. The contact strip, in some
examples, is formed with a portion having a second contact area
which resiliently touches the opposite side of the male lead from
that contacted by the first contact area. Use of the foregoing
connector involves first, inserting the male lead while the contact
strip is in its relaxed state, permitting free insertion, second,
deforming the contact strip in a lengthwise direction to being
about a film wiping contact between the male lead and contact area,
and third, holding the contact strip in its deformed configuration
for as long as electrical contact is desired to be maintained.
Sockets, for example to receive integrated circuit modules with
linear arrays of male leads, employ connectors of the type
described in multiple configuration, with cavity means positioned
for receiving the male leads, a plurality of contact strips
deformable lengthwise to yield the firm wiping contact described
above, movable means for simultaneously deforming a plurality of
the contact strips, and fastener means, such as screws, for holding
the contact strips in deformed configuration.
Inventors: |
William B. Walkup (Southboro,
MA) |
Assignee: |
Cambridge Thermionic
Corporation (N/A)
|
Family
ID: |
22003487 |
Appl.
No.: |
05/056,298 |
Filed: |
July 20, 1970 |
Current U.S.
Class: |
439/264 |
Current CPC
Class: |
H05K
7/1007 (20130101); H01R 13/193 (20130101) |
Current International
Class: |
H01R
13/02 (20060101); H01R 13/193 (20060101); H05K
7/10 (20060101); H05k 001/07 (); H01r 013/54 () |
Field of
Search: |
;339/17C,17CF,17F,17L,17LC,17LM,17M,74,75M,75MP,75T,174,176M,176MP,176MF,191M,192R,258P |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Marvin A. Champion
Assistant Examiner: Lawrence J. Staab
Attorney, Agent or Firm: Roberts, Cushman & Grover
Claims
1. A connector device for making electrical contact with a male
connector element, characterized by low insertion forces imposed on
said male element, comprising means forming a cavity into which
said male connector element can be inserted freely; said cavity
forming means including an elastically deformable contact strip of
conductive material positioned along one side of said cavity, said
contact strip having a first curved portion forming a first contact
area facing an inserted male element, said curved portion tending
to expand across the cavity toward said male element to exert a
force against said male connector element as said contact strip is
deformed in a lengthwise direction, said strip further having a
compressible portion adjacent said curved portion which contracts
as said strip is deformed in a lengthwise direction, thereby wiping
said first contact area along said inserted male connector element,
said strip further having a second curved portion forming a second
contact area positioned to contact substantially the entire
inserted portion of said male connector element on the side
opposite said first contact area; and means movable to deform only
said first curved portion and said compressible portion of said
contact strip in a lengthwise direction without deforming said
second curved portion thereof in a lengthwise direction, thereby to
expand said first contact area across the cavity to exert a contact
force against said male connector element and to wipe said first
contact area therealong, thereby to make electrical contacts
with
2. A connector device according to claim 1 further comprising means
to hold said movable means with said contact strip in deformed
position, thereby
3. A connector device according to claim 1 wherein said cavity
forming means further includes a fixed base member receiving said
contact strip, and wherein said means movable to deform the contact
strip includes a movable base member having a portion securing an
end of said contact strip; and means for holding said fixed and
movable base members with said contact strip in deformed position
thereby to maintain said electrical contacts.
4. A connector device according to claim 3 wherein said fixed base
member and said movable base member have parallel walls between
which said male connector element and said contact strip are
received; and said portion of said movable base member which
secures said contact strip comprises a lip extending from the
parallel wall formed by said movable base member, said lip being
secured to said first curved portion of the
5. A connector device according to claim 1 wherein said first
curved portion and said compressible portion of the contact strip
together have a substantially S-shaped configuration, the lower end
being secured by said cavity forming means, the upper end thereof
being secured by said movable means and being moved towards the
lower end thereof during lengthwise
6. A connector device according to claim 1 wherein said cavity
forming means comprises a fixed base portion and wherein said
second curved portion with said second contact area is secured in
said fixed base member so that said second contact area is
resiliently movable in a lateral
7. A connector device according to claim 1 wherein said contact
strip further comprises a portion extending substantially in the
direction of said male connector element for attachment to other
electrical devices.
8. A low insertion force socket for use with a device having a
plurality of male connector elements comprising: means forming a
plurality of cavities positioned to freely receive said male
connector elements; said cavity forming means including a plurality
of elastically deformable contact strips each positioned along one
side of a male connector element in a cavity; each of said contact
strips having a first curved portion with a convex first contact
area facing an inserted male connector element, said curved portion
tending to expand across the cavity toward said male connector
element to exert a force against said male connector element as
said strip is deformed in a lengthwise direction, said strip
further having a compressible portion adjacent said curved portion
which compresses as said strip is deformed in a lengthwise
direction, thereby wiping said contact area along said male
connector element, and each of said strips further having a second
curved portion forming a second contact area positioned to contact
substantially the entire inserted portion of said male connector
element on the side opposite said first contact area; means movable
to simultaneously deform only said first curved portion and said
compressible portions of each of said plurality of contact strips
in a lengthwise direction without deforming said second curved
portion thereof in a lengthwise direction, thereby to establish
electrical contacts with said male connector elements; and means
for holding said movable means with said contact strips in deformed
position, thereby to maintain electrical contacts established with
said
9. A socket according to claim 8 wherein said cavity forming means
comprises a fixed base member with a plurality of recesses therein
to receive said contact strips, said fixed base member having
spacer means separating recesses and electrically separating said
contact strips, said movable means comprising a movable base member
interfitting with said fixed base member and having a flange formed
therein for holding said
10. A socket according to claim 9 wherein said means for holding
said movable means comprises means interengaging said fixed and
movable base
11. A socket according to claim 8 wherein said plurality of male
connector elements are aligned in a row, and wherein said cavity
forming means comprises a fixed base member having a plurality of
recesses to receive said contact strips, and wherein said movable
means comprises a movable base member adjacent said fixed base
member and having a lip overhanging
12. A socket according to claim 11 wherein said contact strips have
their first curved portions and their compressible portions
substantially in an S-shaped configuration; and said second curved
portions are secured in said fixed base member so that said second
contact areas are resiliently movable in a laterial direction
13. A socket according to claim 11 wherein said contact strips
further comprise a portion for connection with other electrical
devices, said portions extending from said fixed base member
substantially in the
14. A method of establishing electrical contact with a male
connector element, characterized by low insertion forces,
comprising: providing means forming a cavity into which said male
connector element can be freely inserted; providing alongside said
male connector element as part of said cavity forming means an
elastically deformable contact strip having a first curved portion
with a first contact area facing one side of said male connector
element, a compressible portion adjacent to said first curved
portion which contracts when said contact strip is deformed in a
lengthwise direction and a second contact portion having a second
contact area facing the opposite side of said male connector
element to contact substantially the entire inserted portion
thereof; inserting said male connector element in said cavity while
said contact strip is relaxed; and deforming only said first curved
portion and said compressible portion of said contact strip in a
lengthwise direction without deforming said second contact portion
in a lengthwise direction, thereby to urge said first curved
contact portion against said male connector element and to wipe it
therealong and to urge said second contact portion against said
male
15. A method according to claim 14 further comprising holding said
contact strip in deformed position to maintain said electrical
contact.
Description
The field of the present invention relates to electrical connectors
of the type receiving a male component lead, such as is found on an
integrated circuit module or similar device, where high insertion
forces are undesirable.
In current electronic fabrication, it is typical to mount
integrated circuit wafers or chips on standardized interconnection
packages, which have protruding therefrom a number of
interconnecting pins or leads in a standardized pattern for
connection into larger circuit assemblies. As integrated circuits
become more complex and comprehensive, the number of
interconnections with other circuit elements increases, with a
concomitant increase in the number of connector pins or leads
extending from the standardized package. If the advantages of
miniaturized circuitry are to be retained, the mounting packages
must not increase in size very much. This situation yields
integrated circuit packages which have a large number of small,
mechanically weak, leads which are to be connected to other circuit
assemblies.
Connection of the integrated circuit packages with other electronic
assemblies has typically been by direct soldering or by means of
sockets with pin receptacles in a pattern corresponding to the pin
pattern on the package. The sockets can be wired into the assembly
with no chance of thermal damage to the integrated circuits, and
offer the further advantage of easy replaceability of integrated
circuits should they become defective. However, the interconnection
of an IC package and its socket raises problems as the number of
interconnections increases. First, each pin-socket connection
requires a given amount of insertion force for reliable contact,
since it is typically necessary to provide a forceful wiping
contact to remove high resistance films which form on pin or socket
elements. The total force needed can become high if there are a
large number of connections to be made, which makes accurate
insertion into the socket difficult. Second, as the number of
connectors increases, their mechanical strength tends to decrease
in order to retain space advantages. Third, as the number of
connectors increases, it is typical that the value of the
integrated circuit increases in a geometric relationship. Thus any
destruction of a lead, which would result in the rejection of the
entire package, would have great economic consequences. Thus, it
can be seen that a number of factors working together call for some
improved manner of connecting integrated circuit packages into
electronic assemblies so as to minimize the possibility of package
destruction or damage during the interconnection, and preferably
without losing the advantages of easy replaceability and thermal
safety offered by socket connectors. Many of the same problems are
found not only in connection of integrated circuit packages, but
are found also in other connection contexts where for some reason
one of the connectors is fragile, or the net insertion force is
excessive, or the cost of damaged components is high.
Objects of the present invention are to provide a device for making
electrical contact with a male connector or pin or lead which
permits electrical connection to be made easily and reliably with
minimal likelihood of harm to the male connector, and which can be
easily and inexpensively manufactured in sizes corresponding to
those presently utilized for integrated circuit packages, and which
further permits the male connector to be removed or replaced.
According to the invention, the device for making electrical
contact with a male connector is characterized by imposition of low
insertion forces on the male connector and comprises an elastically
deformable contact strip of conductive material, means including
said contact strip for forming a cavity into which the male
connector is freely insertable when said contact strip is relaxed,
and means to deform said contact strip in a lengthwise direction.
The contact strip has a curved portion with its convex surface
forming a contact area facing the inserted male connector, a said
curved portion tending to expand its contact area across the cavity
to exert a force against the male connector as said contact strip
is deformed in a lengthwise direction. The contact strip preferably
further has a second portion adjacent the curved portion, which
compresses as the strip is deformed in a lengthwise direction,
thereby wiping said contact area along the male connector for
removal of non-conductive films and reliable contact. Means are
also preferably provided for holding the contact strip in its
deformed position of contact with the male connector. The device of
the present invention is used by first, placing the contact strip
in its undeformed position, second, freely inserting the male
connector in the cavity alongside the undeformed contact strip,
third, deforming the contact strip in a lengthwise direction to
bring the contact strip into reliable electrical contact with the
male connector, and fourth, retaining the contact strip in its
deformed configuration to maintain the contact.
Preferably, the contact strip has not only the first and second
portions described above, but also a third portion connected to the
second portion and facing the contact portion for contact with the
male connector, the third portion preferably resiliently supporting
the male connector.
In another aspect, the invention is a socket employing a plurality
of connector devices as described above, and designed for use with
a package having a plurality of male connectors. The socket
comprises cavity means receiving the male connectors, a plurality
of contact strips deformable lengthwise so as to provide the wiping
contact described above, means movable to simultaneously deform a
plurality of said contact strips, and means for holding the movable
means with the contact strips in deformed position. Preferably the
cavity means is formed with a molded plastic base receiving the
contact strips and the movable deforming means is a mount for said
contact strips which is attached to one of the base members and
which causes the strip to be deformed as the member is moved.
These and other objects and novel aspects of the invention will be
apparent from the following description of preferred
embodiments.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a connection device according to the
invention;
FIGS. 2, 3, and 4 are side views of the connector of FIG. 1
illustrating successive positions of the contact strip as it is
deformed in a lengthwise direction to establish electrical
contact;
FIG. 5 is a plan view, partially broken away, of a socket according
to the invention;
FIG. 6 is a right end view of the socket of FIG. 5;
FIG. 7 is a section on line 7--7 of FIG. 5;
FIG. 8 is a bottom view of the socket of FIG. 5;
FIG. 9 is a section on line 9--9 of FIG. 7;
FIG. 10 is an isometric view of another embodiment of the
invention;
FIG. 11 is a plan view of still another embodiment of the
invention, adapted to receive a printed circuit card;
FIG. 12 is a section on line 12--12 of FIG. 11 showing the device
in position for insertion of a printed circuit card;
FIG. 13 is a section similar to FIG. 12, showing the device
positioned to establish electrical contact;
FIG. 14 is a section on line 14--14 of FIG. 11; and
FIG. 15 is a partial section, similar to FIG. 14, showing
1-modification.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1--4 illustrate the basic construction and operation of an
electrical connecting device 10 of the present invention, designed
to accept and make electrical contact with a male connector 12
associated with an arbitrary electrical device 14, a portion of
which is shown in the drawing. The connecting device 10 as
illustrated, comprises an elastically deformable contact strip 16
of conductive material, e.g., beryllium copper initially shaped on
a slide press and subsequently hardened to provide appropriate
springness or elasticity. The deformable contact strip 16 lies in a
recess 18 formed between a fixed base member 20 and a movable base
member 22, both of which can be molded from a non-conductive
plastic material. In brief summary, the deformable contact strip,
when in relaxed position (FIGS. 1 and 2) forms an open pocket or
cavity 24 in which the male connector 12 may be freely inserted,
with little or no insertion force. Thereafter, the base member 22
is moved relatively to the base member 20 (downwardly in FIGS. 3
and 4) to deform the contact strip 16 in a manner which causes a
contact area 26 of the strip 16 to first contact the connector 12
(FIG. 3) and to then rub therealong under firm pressure for
efficient film removal and effective electrical contact
therebetween (FIG.4).
In greater detail, the construction of deformable strip 16 and base
members 20 and 22 to provide the operation described above is as
follows. The deformable contact strip 16 can be subdivided
functionally into four portions. A first portion 16.1 extends
through a hole 28 in fixed base member 20 for connection to other
electrical circuit components as by soldering, wire wrapping, or
the like. As illustrated, the portion 16.1 may be situated
substantially collinear with the connector 12 so that the device 10
establishes the same pattern for connections as the electrical
device 14, thereby making the device 10 compatible with standard
circuit board patterns and procedures. A second portion 16.2 of the
strip 16 provides a resilient wall at one side of the cavity 24 in
which the connector 12 is inserted. This resilient portion 16.2 is
comprised of an offset portion 16.21 extending from connector
portion 16.1 over a ledge 30 provided in base member 20, a
relatively flat portion 16.22 resting against interior surface 32
of base member 20, and another relatively flat portion 16.23 folded
over from the portion 16.22 to provide one side of pocket 24. So
formed, the side 16.23 is not rigid, but provides resilient support
for connector 12, and an additional contact surface 16.24 touching
connector 12 opposite contact surface 26. As shown in FIG. 3, the
lower end of portion 16.23 swings over to bear against the upper
end of portion 16.1 as the connector is closed, and then remains
secured in this position as the connector is closed further to
provide the wiping contact described above.
The remaining two portions 16.3 and 16.4 of the contact strip 16
provide the desired wiping contact. Portion 16.4 is a curved or
bent portion whose outer convex surface faces the male connector 12
and forms the contact area 26 which rubs thereagainst. The portion
16.3 is an initially flat portion which lies against inner surface
34 of movable base member 22 when the contact strip is relaxed
(FIG.2), and which swings away therefrom as the upper end of
portion 16.4 is pushed downwardly by overhanging lip 36 provided on
movable base member 22 (FIG. 3). When the lower end of portion
16.23 meets the stop provided by the upper end of portion 16.1, as
shown in FIG. 3, the lower end of the compressible portion 16.3 is
firmly fixed. Further downward motion of movable base 22 results in
the lengthwise deformation of portions 16.3 and 16.4, which results
in the bending of portion 16.3 to reduce its lengthwise dimension,
and in the downward travel of contact area 26 along male connector
12. At the same time that the contact area 26 is wiped along the
connector 12, the curved portion 16.4 is pushed with increasing
sidewise force against connector 12, this force being resisted by
the resilience provided by portion 16.2 and contact area 16.24 with
the result that the connector 12 is reliably secured in a pinching
fashion between the two contact areas. As shown by FIGS. 3 and 4,
the portions 16.3 and 16.4 substantially form an S-shape whose ends
are moved closer to one another as the connector is closed, with
the result that the S-shape becomes shorter and wider, this action
urging the contact surface 26 both outwardly against and downwardly
along the member 12 against which it rests.
It can be appreciated that the provision of resilient backing
portion 16.2 not only provides an additional contact area 16.24 for
lower contact resistance, but also permits pocket 24 to be made
wider, and to handle a larger range of thicknesses of connectors
12, for any given set of positional and flexural tolerances imposed
on the contact strip 16 and on the base members 20 and 22. Thus,
the pinching forces on connector 12 can be made more uniform, and
less dependent on positioning of contact strip portions 16.3 and
16.4 and on thicknesses of connectors 12.
Once portions 16.3 and 16.4 of contact strip 16 have been deformed
in a lengthwise direction to produce electrical contact with
connector 12, the contact strip 16 is maintained in its deformed
configuration, as symbolized by pin 38 engaging base members 20 and
22 and preventing their relative movement (FIG. 4).
From the above description of the construction and operation of the
connector device 10, it can be seen that base members 20 and 22
engaging contact strip 16 exist to provide fixed support for the
portions 16.1 and 16.2 of the contact strip and movable support for
the end of portion 16.4 permitting lengthwise deformation of
portions 16.3 and 16.4. Thus, a number of constructional variations
are possible, e.g., instead of making lip 36 integral with a
movable base member 22, an alternative construction attaching a
movable lip to a fixed base member could be used. Other such
variations will be apparent.
It is similarly apparent that variations in construction of contact
strip 16 can also be made, for example, by omitting or modifying
one or more of the four portions which compose it. Resilient
portion 16.2 might be omitted if its added contact area and
resilient support were not needed; external connection portion 16.1
might be omitted if other connection provisions were made;
compressible portion 16.3 might be shortened or eliminated if
curved portion 16.4 were sized to provide an adequate rotation or
bending to wipe contact area 26 along the male connector 12;
similarly, curved portion 16.4 might take different shape and still
provide a contact area 26 to be brought into wiping contact with
male connector 12. Some of these variations are illustrated in the
following embodiments in which parts similar or analogous to those
described with reference to FIGS. 1-4 are designated by the same
numerals, prefixed with the added numeral 1, 2 or 3. Thus, the
numerals 12, 112, 212 and 312 designate similar parts.
FIGS. 5-9 illustrate a socket 100 utilizing a plurality of
connector devices 110 each similar to the device 10 described
above, and adapted to receive electrical connectors 112 extending
from an electrical device 114. The particular device 114
illustrated comprises a flat oblong slab 114.1 upon which an
integrated circuit chip 114.2 is placed, and two rows of connectors
112 extending downwardly from opposite sides of the slab. The
connectors 110 of the present invention are particularly
advantageous when used with this type of device, which is fragile,
susceptible to thermal destruction, and expensive to replace.
The socket 100 comprises a fixed base member 120, adapted to rest
on a circuit board, for example, and a movable base member 122
interfitting therewith so as to permit sliding vertical movement.
Both fixed and movable base members can be molded with plastic
materials. A plurality of screws 138 interconnect fixed base member
120 and movable base member 122, and as will be explained
hereafter, serve as the means for closing the connectors 110 and
holding them in closed contact position.
Fixed base member 120 is generally rectangular, but is provided
with end cut-outs or slots 140 and side cut-outs or slots 142
respectively receiving end flanges 160 and side flanges 162
extending down from movable base member 122. At the corners of
fixed base member 120, there remain platforms 144 which threadably
engage screws 138 with threads provided therein or in a threaded
insert. Movable base member 122 is provided with a central opening
164 to receive the electrical device 114 and has a chamfer 166 at
each end to facilitate finger gripping of the electrical device
114.
To accommodate the contact strips 116, similar to contact strip 16
described above, the fixed base member 120 is provided with a
plurality of recesses 118 in the edges thereof which face the side
flanges 162 FIG. 9). The recesses 118 are spaced to match the
spacing of male connectors 112, and are separated by integral
spacers 146 which electrically insulate the contact strips 116 from
one another. In each recess 118, the fixed base member 120 has a
ledge 130 and an aperture 128 corresponding to ledge 30 and
aperture 28 described above. The other end of contact strip 116 is
accommodated in movable base member 122 by means of recesses 168
therein which are aligned with recesses 118 and bounded by
overhanging flange 136 and lateral spacers 170 aligned with spacers
146 to ensure electrical separation of the contact strips 116.
The socket 100 illustrated in FIGS. 5-9 is typically mounted on a
circuit board or the like with connections made to the portions
116.1 of the respective contact strips. To insert an electrical
device 114 in the socket, the screws 138 are positioned so that the
movable base member 120 is spaced away from the fixed base member
120 to put contact strips 116 in relaxed position with the cavities
124 thereof opened to receive connector pins 112. The connector
pins 112 are inserted with minimal force into the opened cavities
124. Screws 138 are then rotated to bring fixed and movable base
members 120 and 122 closer together to thereby simultaneously
deform the contact strips 116 with consequent electrical contact
and film wiping action. When contact is completed, the screws 138
serve as means to hold the contact strips 116 in deformed position
for as long as it is desired that contact be made. Removal of the
electrical device 114 is accomplished by rotating screws 138 to
separate base members 120 and 122. The contact strips 116 return to
their relaxed position and the connector pins 112 can be freely
removed therefrom.
FIG. 10 illustrates yet another embodiment of the invention, a
connector device 200 which comprises a fixed base member 220
forming a recess 218 which accommodates a deformable contact strip
216. As illustrated, base member 220 is substantially U-shaped,
with opposed walls 232 and 234 confining the contact strip 216. The
contact strip 216 differs from contact strips 16 and 116 in that it
has its connector portion 216.1 in line with the portion 216.22
which rests against wall 232, omitting an offset portion such as
portion 16.21 of FIGS. 1-4.
The free end 216.41 of the contact strip 216 is confined under an
overhanging flange 236 of a member 222. The member 222 is provided
with a snap-tang fastener 238 which is receivable in an undercut
slot 239 provided in base member 220, the interfitting fastener 238
and slot 239 being positioned to lock together when the contact
strip 216 has been deformed to make electrical contact with
connector pin 212 of electrical device 214. It should be apparent
that the modifications illustrated in FIG. 10 respecting base
member construction, contact strip construction, and construction
of the means to hold the contact strip in deformed position, could
be substituted for their respective counterparts in the device 10
and socket 100 illustrated in FIGS. 1-9.
FIGS. 11 through 14 illustrate a printed circuit card connector 300
using minimal insertion force connectors according to the
invention. The device is adapted to make electrical connection with
a printed circuit card 314 which has provided therein a plurality
of surface contacts 312 on both sides of the card 314 along one
edge thereof. The surface contacts 312 are connected to various
circuit items on card 314 and are usually provided by printed
circuit techniques. The connector device 300, typically mounted on
a circuit board B, comprises a fixed base member 320 and a movable
base member 322 fastened thereto by means of jack screws 338 for
travel toward and away from the fixed base member 320. The movable
base member 322 is provided with a central opening 364 to receive
the card 314 and has an overhanging flange 336 at opening 364. A
plurality of contact strips 316, one for each surface contact 312,
are mounted between flange 336 and fixed base member 320, the
contact strips 316 being separated from one another by spacers 346
integrally formed with fixed base member 320. The spacers 346
extend into central opening 364 and have rounded upper ends 347 to
help guide the printed circuit card 314 therein. Each contact strip
316 has a connector portion 316.1 extending through a hole provided
in fixed base 320, an offset portion 316.21 to secure the contact
strip against fixed base member 320, a compressible portion 316.3,
and a curved contact portion 316.4 whose end fits underneath flange
336. Portions 316.3 and 316.4 of contact strip 316 function in a
manner similar to portions 16.3 and 16.4 of the contact strip 16
described above, these portions changing shape when deformed
lengthwise so as to develop a wiping electrical contact between
contact area 326 thereof and the surface contacts 312 of card 314.
Use of card connector 300 is similar to use of the socket 200
described above: To insert a card 314, screws 338 are positioned as
in FIG. 12 so that fixed and movable base members 320 and 322 are
separated and the contact strips 316 are relaxed to freely admit
the card 314 therebetween. With the card in place, screws 338 are
tightened to lengthwise deform the contact strips 316 and bring
about the desired electrical contact with the surface contacts 312
of the card, as in FIG. 13. Removal of a card 314 is accomplished
by reversal of the above steps.
Instead of using screws 338 as shown in FIGS. 11 through 14, a
camming means may be used instead. FIG. 15 illustrates a portion of
a card connector similar to that of FIGS. 11 through 14 modified to
substitute a camming means 350 for the screws 338. The camming
means 350 comprises a pin 352 secured to fixed base member 320 and
extending through a hole provided in movable base member 322.
Rotatably mounted on crossbar 354 at the top of pin 352 is a
camming lever 356 with a camming surface 358 bearing against the
surface of movable base 322 to urge it toward fixed base 320 as
lever 356 is rotated, the surface 358 having a flat 359 to lock cam
lever 356 in a position corresponding to deformation of the contact
strips 316.
* * * * *