Note: Descriptions are shown in the official language in which they were submitted.
BACKGR~UN~ OF THE INVENTI~N 1 17 7 5 ~1
Fie~d of the Inven~ion
This invention relates to the field o~ e~ectrical connectors1
and more particularly to electrical connectors or connecting a
printed wiring card to a back plane.
Desc~iption of the Prior ~t
Various types of connectors currently exist in the
marketplace for electrically and physically connecting a printed
wiring card on which electrical components are mounted to a back
plane. Perhaps the most common type of connector is the edge-on
connector. The edge-on connector provides a sliding contact
interface to the printed wiring card, yielding a quick and
relatively easy means of installing or removing printed wiring
cards.
The edge-on connector, while quite popular, does contain
several drawbacks inherent in its design. First, repair or
replacement o a damaged connector pin can be a very difficult
and time consuming task due to the often resulting congested
wiring on the back plane. In addition, the fact that the
individual pins of the edge~on connector are soldered in place on
the back plane further complicates this task. A second drawback
of the edge-on connector i9 the fact that any one edge-on
connector type is restricted to accommodating printed wiring
cards of a fixed thickness. A variation in the thickness of a
printed wiring card, as a result in a variation of the number of
individual layers of printed wire runs on the printed wiring,
card, requires edge-on connectors of varying si~es~
A second type oE connector for electrically and physically
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connecting a printed wiring card to a back plane is the plug-on
connector. Typically, the plug-on connector is restricted to
being mounted on only one side of a printed circuit card, and can
employ either a single or multiple rows of connecting pins.
An advantage of the plug-on connector is a higher density of
connections per linear inch due to the use of an individual
connection pin for each connection as opposed to a linear portion
of the printed wiring card as is used with a printed wiring card
used with an edge-on connector. This feature provides even
greater density of connections when multiple rows of connection
pins are used. While the plug-on connector does yield a higher
density of connections per linear inch, it suffers from the same
problem inherent in the edge-on connector with respect to repair
or replacement of connection pins physically attached to the back
panel.
Due to the relatively large number of connection pins that
are customarily present in large systems, and the great
difficulty associated with the repair or replacement of a damaged
connection pin, it is desirable to separate a portion of the
connection pins affixed to the back plane which are used for
wiring purposes from that portion of the connection pin which
serves to electrically connect the printed wiring card to the
back plane. This approach is used with a pressure-pressure
connector type.
The pressure-pressure connector functions to connect a
printed wiring cad to a back plane by a plurality of single
electrical connections~ As the pressure connector type does not
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involve the physical interconnecting with a pin on the back
plane, the risk of damaging a pin which in the case o the
edge-on or plug-on connector is soldered in place beneath a large
amount of congested wiring on the back plane, does not exist. A
drawback of the pressure-pressure connector, however, is the fact
that the pressure-pressure connector must be rigidly mounted to
both the printed circuit card as well as the back plane. This
results in a somewhat inconvenient arrangement with respect to
removal of the printed wiring card.
1o SUMMARY OF THE INVENTION
Thereforel there is provided by the present invention, a
connector for electrically connecting terminal points of a
printed wiring card to corresponding terminal points of a
backplane which comprises a first block of a dialectric material
having embedded therein a plurality of connection pins of an
electrically conducting material, a first end of each of the
connection pins protruding from a first surface of the first
block and a second end of each of the connection pins protrudiny
from a second surface of the first block, wherein the first and
second surface are essentially at right angles to each other.
The connector also includes a second block of a dialectric
material, a spacer element having a first predetermined
thickness, and an element for fastening the first block to the
second block. ~ -> (continues)
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The spacer element is po~itioned between the Eirs~ block and the
second block causing a space of the first predeter~lined thickness
to exist between the first block and the second block, the space
adapted to receive the printed wirin~ card having a second
predetermined thickness. The place of protrusion of each of the
first end of the connection pin ~rom the first surface o~ the
first block aligns with the corresponding terminal point of the
printed wiring card when the printed wiring card is inserted in
the space, and the amount of protrusion of each of the first end
of the connection pin from the first surface of the first block
is essentially a fixed amount such as to cause a first pressure
contact between each of the first end of the connection pin and
the corresponding terminal point of the printed wiring card when
the printed wiring card is inserted in the space. A second
element for fastening the first block to the backplane, such that
the place of protrusion of each of the second end of the
connection pin from the second surface of the first block aligns
with the corresponding terminal point of th~ backplane! and the
amount of protrusion of each of the second end of the connection
pin rom the second surface of the first block is sufficient to
make an electrical connection when held in pressure contact
against the terminal point of the backplane.
In the preferred embodiment disclosed herein, the connector
described herein provides a high density of electrical
connections by employing a double tier arrangement of electrical
contacts.
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1 ~75~1
Accordingly, it is an object o~ the present invention to
provide a highly versatile connector which can be used to provide
electrical connections to one or both sides of a printed wiring
card.
It is another object of the present invention to provide an
electrical connector which can accommodate printed wiring cards
- of varying thicknesses,
It is a further object of the present invention to provide a
highly versatile connector which can be used to provide
electrical connections to one or both sides of printed wiring
cards of varying thicknesses.
It is yet another object of the present invention to provide
a connector for connecting a printed wiring card to a back plane
which cannot reflect damage to the back plane pins and associated
wiring.
It is still a further object to provide a connector which
offers a high degree of flexibility and application, as well as a
high density of electrical connections while remaining economic
in use.
The foregoing and other objects, features and advantages of
the invention will become apparent from the following more
particular description of a preferred embocliment of the
invention, as illustrated in the accompanying drawings.
DESCRIPTION OF DP~A~INGS
The various novel features of this invention, along with the
foregoing and other objects, as well as the invPntion itself both
as to its organization and method of use, may be more fully
understood from the following description of an illustrated
embodiment when read in con~unction with the accompanying
drawings, wherein:
Figure 1 is a perspective vies of an edge-on connector and an
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associated printed wiring card oE the prior art
Figure 2 is a side view of an edge-on connector affixed to a
back plane of the prior art;
Figure 3 is a side view of a plug-on type connector affixed
to a printed wiring card adjacent to a back plane of the prior
art;
Figure 4 is a side view of a pressure-pressure type connector
affixed to a printed wiring card and a back plane of the prior
art;
Figure 5 is a side view of the connector made the subject of
the present application affixed to a back plane providing
electrical connections to one side of a printed wiring card;
Figure 6 is a side view of the connectors made the subject of
the present application affixed to a back plane providing
electrical connections to both sides of a printed wiring card;
and
Figure 7 is a view of a portion of an edge of a printed
wiring card illustrating a double tier of offset electrical
connections as used in connection with the preferred embodiment
of the invention herein.
DES(~RIPTION QF TEIE ~EFERRED ErqBODI~lENT
In order to more easily understand the features of the
present invention, some connectors of the prior art will first be
discussed. Perhaps the most common type of connector is the
edge-on connector, as illustrated in Figure 1. With the edge-on
connector arrangement, an edge 101 of the printed wiring card 102
has a plurality of electrical contacts 103 fabricated along one
edge. The edge-on connector 104 has a matching number of
electrical contac~s 105 arranged along an inner gap 106 of
edge-on connector 104 which mate with electrical contacts 103 on
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3 :~77~1
printed wiring card 102 when the edge 101 o~ the p~lnted wi~ing
card 102 is inserted into the gap 106 of edge-on connector 104.
A side view of the edge-on connector is illustrated in Figure 2.
The edge~on connector is composed of a housing 201,
connection pins 202 which extend ~rom the point of connec~ion to
the printed circuit card 203 through the connector housing 201 to
the rear of the connector housing, and a mounting of the
connector housing 2G1 to the back plane 104 by mounting means
205.
The edge-on connector can provide connections to a printed
wiring card on either one or both sides of the printed wiring
card by appropriate connection pins 203~ The connection pins 203
can be made individually removable from the connector housing 201
for repair and replacement purposes.
The edge-on connector provides a sliding contact interface to
the printed wiring card, yielding a quick and relatively easy
means of installing or removing printed wiring cards.
The connection pins 203 are electrically connected to the
back plane by individually soldering each pin to its respective
location on the back plane. Thereafter, the numerous pins of the
various edge-on connectors soldered to the back plane are
interconnected by individual wires. The resulting wiring on the
back plane is often quite congested.
It is observed that the edge-on connector requires an edge of
the associated printed circuit card to serve as a male type
connector, with the edge-on connector serving as the female
connector.
The edge-on connector, while quite popular, does contain
several drawbacks inherent in its design. First, repair or
replacement of a ~
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damaged connector pin 203 can be a very di~ficult and time
consuming task due to the often resulting congested wiring on the
back plane. In add~tion, the fact that the individual pins of
the edge-on connector are soldered in place on the back plane
further complicates this task.
A second drawback of the edge~on connector is the fact that
any one edge-on connector type is restricted to accommodating
printed wiring cards of a fixed thickness. A variation in the
thickness of a printed wiring card, as a result in a variation of
the number of individual layers of printed wire runs on the
printed wiring card, requires edge-on connectors of varying
sizes.
A second type of connector for electrically and physically
connecting a printed wiring card to a back plane is the plug-on
connector, a side view of which is i-llustrated in Figure 3. The
plug-on connector is composed of two parts: a male portion 301
which is mounted on the associated printed circuit card 302, and
a female portion 303 which is mounted on the back plane 306. The
individual connection pins 304 of the female portion ~03 extend
through the back plane in a similar fashion as the edge-on
connector connection pins, and are soldered in place on the back
plane.
Typically, the plug-on connector is restricted to being
mounted on only one side of a printed circuit card, and can
employ either a single or multiple rows of connecting pins 305.
An advantage of the plug-on connector is a high~r density of
connections per linear inch due to the use of an individual
connection pin for each connection as opposed ~o a linear portion
of the printed wiring card as is used with a printed wiring card
used with an edge-on ~ ~ ~
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connector. This Eeature provides even greateL density o~
connections when multiple rows of connection pins 305 are used.
While the plug-on connector does ~ield a higher density of
connections per linear inch, it suffers from the same problem
inherent in the edge-on connec~or with respect to repair or
replacment of connection pins physically attache~ to the back
panel 306.
In addition, the plug-on connector requires the use of two
separate connectors for each connection, i.e., a male connector
301 permanently mounted on the printed wiring card 302, and a
female connector 303 permanently mounted on the back plane 306.
Consequen~ly, the cost assGciated with the use of the plug~on
type connector is necessarily greater than that of the edge-on
connector type.
Due to the relatively large number of connection pins that
are customarily present in large systems, and the great
difficulty associated with the repair or replacement of a damaged
connection pin, it is desirable to separate a portion of the
connection pins affixed to the back plane which are used for
wiring purposes from that portion of the connection pin which
serves to electrically connect the printed wiring card to the
back plane. This approach is used with the pressure-pressure
connector type. A side view of the pressure-pressure connector
type is illustrated in Figure 4.
The pressure-pressure connector Eunctions to connect a
printed wiring card 401 to a back plane 402 by a plurality of
single electrical connections 403. The electrical connections
403 are in pressure contact with the desired electrical
connec~ion points on both the back plane 405 and the printed
wiring card 404 The pressure-pressure connector housing 406 is
affixed to the printed wiring card 401 by mounting means~
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407. The printed wiring card is affixed to ~he back plane 402 by
mounting means 408. A~ the pre.ssure-pres~ure connector type does
not involve the physical interconnecting with a pin on the back
plane, the risk of damaging a pin which in the case of the
edge-on or plug-on connector is soldered in place beneath a large
amount of congested wiring on the back plane, does not exist~ A
drawback of the pressure-pressure connector, however, is the fact
that the presure-pressure connector must be rigidly mounted to
both the printed circuit card as well as the back plane. This
results in a somewhat inconvenient ~rrangement with respect to
removal of the printed wiring card.
A side view of an embodiment of the invention made the
subject of this application is illustrated in Figure 5.
Connector 501 is affixed to back plane 502 by mounting means 503,
and connects points 505 and 506 on printed wiring card 504 with
points 507 and 508 respectively on back panel 502. Connector
retaining bar 509 functions to aid in retaining printed wiring
card 504 in position adjacent to connector 501, and is secured in
place by mounting means 512 which is affixed to connector 501 and
retaining bar 509, passing through a slot 513 in printed wiring
board 504. A space means 514 functions to define and maintain
the desired distance between connector 501 and retaining bar 509
for the appropriate thickness of printed wiring board 504.
Several points are noted with respect to Figure 5. First,
the connection interace between connector 501 and printed wiring
card 504 is a sliding interace, i.e., electrical connections are
made between connector 501 and printed wiring card 504 when
printed wiring card 504 is slid into place between connector 501
and connector retaining bar
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509, thereby bringing connection pins 510 and 511 of connector 501 into
electrical contact with the desired connection points 505 and 506 on
printed wiring card 504.
Secondly, the electrical connection interace between connector 501
and back panel 502 is a pressure interface, i.e~, electrical connection
between back panel terminal points 507 and 508 and connection pins 510
and 511 of connector 501 are held in pressure contact with back panel
502 by mounting means 503. Consequently, connector 501 furnishes an
electrical interface between printed wiring card 504 and back panel 502
without the necessity of connector 591 connection pins being soldered to
back panel 502. By so providing for a pressure interface with the back
panel, the very difficult practical problem of dealing with the
ramifications of damaged connector pins on the back panel has been
elLminated.
It is also observed from Figure 5 that connector 501 physically
mounts only on the back plane and the associated retaining means,
retaining bar 509, or, as is subsequently described herein, the
corresponding connector for providing electrical connections to the
opposite side of the printed wiring board. Connector 501, while
providing a sliding interface to printed wiring card 594, does not
require a physical mounting to printed wiring card 504, as was reguired
with the pressure-pressure connector illustrated in Figure 4.
Consequently, printed wiring card 504 is easily removable from connector
501.
Another feature inherent in ~he connector made the subject of the
present ap~lication is the fact that the identical type connector can be
1 177551
used to provide electrical connections to either or both sides of the
printed wiring card. As illustrated in Figure 6, printed wiring card
601 has connector 603 and 604 positioned on opposite sides adjacent to
back panel 602. By so providing electrical connections along an edge of
the connector, the identical connector can provide electrical connec-
tions between either or both sides of a printed wiring card and back
plane.
An additional feature which naturally follows from the design of
the connector is the capability of providing electrical connections to
either or both sides of a printed wiring card, independently of the
thickness of the printed wiring card. m is feature would be
particularly attractive to manufacturing facilities where the thickness
of the printed wiring cards may vary due to the layers of printed wiring
present on printed wiring cards. With the present connector, variations
in board thicknesses do not impact the use of the connector, as would be
the case with the edge-on connector. To the contrary, the same
connector can be used, with adjusting only the connector-to-connector
distance to reflect the change in thickness of the printed wiring card~
m is function is accomplished by spacer means 609 which serves to define
and maintain the desired distance between connectors 603 and 604 for the
appropriate thickness of printed wiring board 601. Conse~uently, the
same connector can be used, to provide electrical connections to one or
both sides of printed wiring cards of varying thicknesses.
me invention made the subject of the present application also
provides for the use of offset multiple tiers of electrical contacts on
the sliding electrical contact interface with the printed wiring cardO
1 1775~1
Figure 5 illustrates a side view of the connector employing an offset
double tier 510 and 511 of electrical contacts. Figure 6 illustrates
the connector made the subject of the present application employing an
offset double tier of connections 605, 606 and 607, 608 to provide
electrical connections to both sides of printed wiring board 601.
In the preferred emb~diment of the connector herein, the offset
between adjacent tiers of electrical connection points was chosen to be
equal to one-half of the width between adjacent electrical connection
points. This is illustrated in Figure 7, which illustrates a portion of
one edge of a printed wiring board used with the connector described
herein.
In the preferred embodiment of the connector made the subject of
the present application, the connective elements 510 and 511 shown in
Figure 5 between the printed wiring card 504 and the back plane 502 are
solid metalic connectors.
m e above description is included to illustrate the preferred
embodiment of the present invention, and is not meant to limit the scope
of the invention. The scope of the invention is to be limited only by
the following claims. From the above discussion, many variations will
be apparent to one skilled in the art that would yet be encompassed by
the spirit and scope of the invention herein.
