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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electrical connectors and, more particularly, to
bi-level card edge connectors and a method of manufacturing the same.
2. Prior Art
In electrical arts it is a common practice to use a connector to
mechanically and electrically couple a mother printed circuit board with a
daughter printed circuit board as of the vertical edge card variety. In
such a practice, there has been an evolution towards placing electrical
contacts closer and closer together while maintaining a high, constant
stress between the electrical contacts and the areas to be contacted. In
placing the contacts closer together, as to 20 contacts per linear inch,
the width of each contact must decrease. One such connector is found in
U.S. Pat. No. 4,846,734, entitled "Vertical Edge Card Connectors" by
Thomas G. Lytle which is assigned to the same assigned as herein and is
incorporated by reference in its entirety herein.
There has also been developed a special type of connector which is known in
the art as a bi-level connector; i.e.: a connector having two types of
contacts that make contact with a daughter printed circuit board in two
locations or at two levels. The two types of contacts are generally
intermixed or alternatingly arranged in two opposing rows. The first type
of contacts are arranged at a predetermined pitch, such as 100 mils,
between the first type of contacts. The second type of contacts are also
arranged at a predetermined pitch, such as 100 mils, between the second
type of contacts such that there is a 50 mils pitch between the adjacent
first and second contacts. One such connector is described in copending
patent application Ser. No. 07/287,765, filed Dec. 21, 1988, now U.S. Pat.
No. 4,934,961, entitled "Bi-Level Card Edge Connector And Method of Making
The Same" by Piorunneck et al. which is assigned to the same assignee as
herein and which is incorporated by reference in its entirety hereby.
U.S. Pat. No. 4,045,114 to Dechelette discloses a two part housing for an
electrical connector that are bonded together to secure the contacts in
their required positions. U.S. Pat. No. 4,842,538 to Noschese disclosed a
card edge connector having a body shell and follower with bi-level
contacts therebetween. U.S. Pat. No. 4,179,177 to Lapraik discloses a card
edge connector with an outer housing and inner housing. U.S. Pat. No.
4,298,237 to Griffith et al. discloses a card edge connector having
contacts at three levels aligned in columns.
However, even thought the art is replete with many different types of
connectors, a problem still exists with providing a card edge connector
with contact spacing at a sufficiently close and dense an arrangement to
allow for faster communication between mother and daughter printed circuit
boards such as with the use of more numerous contacts and yet still be
suitably sized for practical applications such as in relatively small
desktop computers. One problem in this regard is that prior art connectors
have been only 8, 16 and 32 bit connectors. Whereas higher bit connectors,
such as 128 or 256 bit or higher, could obviously transmit signals at a
higher rate of speed than old connectors. However, one major problem with
connectors having closely spaced contacts is the problem of cross-talk and
induction between the contacts due to electromagnetic forces. A further
problem exists in that faster signals have larger electrical spikes which
produce stronger electromagnetic impulses. In addition, another problem
with connectors is that the contacts must provide a relatively short or
direct path between the daughter board and mother board to prevent
propagation delays and, the signal sent through the contacts must be
impedance matched to prevent reflection waves.
It is therefore an objective of the present invention to provide a new and
improved connector and method of manufacturing the same that can overcome
the above problems in the prior art as well as provide additional features
and advantages.
SUMMARY OF THE INVENTION
The foregoing problems are overcome and other advantages are provided by a
bi-level card edge connector having a plurality of closely spaced
contacts.
In accordance with one embodiment of the present invention, an electrical
connector is provided for mechanically and electrically connecting a
mother printed circuit board and a removable daughter printed circuit
board of the edge card type. The connector has a first housing, a
plurality of a first type of contacts, a plurality of a second type of
contacts and a contact separator. The first housing is comprised of an
electrically insulating material and has a top surface with a slot for
receiving a portion of a daughter printed circuit board and at least two
rows of contact chambers on opposite sides of the slot. The first type of
contacts are positioned in at least some of the contact chambers with the
first type of contacts having a relatively tall height in the contact
chambers. The second type of contacts are positioned in at least some of
the same contact chambers as the first type of contacts and have a
relatively short height in the contact chambers. The contact separator is
located, at least partially, inside the contact chambers between portions
of the first and second types of contacts located in the same contact
chambers.
In accordance with another embodiment of the present invention, an
electrical connector is provided for mechanically and electrically
connecting a mother printed circuit board and a removable daughter printed
circuit board of the edge card type. The connector comprises a housing, a
plurality of a first type of contacts, and a plurality of a second type of
contacts. The housing has a first housing member and a second housing
member. The first housing member is comprised of an electrically
insulating material and has a top surface with a first slot, a first
series of contact chambers communicating with the first slot, and a bottom
aperture communicating with the first slot. The second housing member is
comprised of an electrically insulating material and has a second slot and
a second series of contact chambers communicating with the second slot.
The second housing member is, at least partially, positioned in the first
housing member bottom aperture with the first slot aligned with the second
slot for receiving a portion of a daughter printed circuit board therein.
The first type of contacts are positioned in at least some of the first
series of contact chambers and have a relatively tall height therein. The
second type of contacts are positioned in at least some of the second
series of contact chambers and have a relatively short height relative to
the first type of contacts.
In accordance with one method of the present invention a method is provided
of manufacturing an electrical connector for mechanically and electrically
connecting a mother printed circuit board and a removable daughter printed
circuit board of the edge card type. The method comprises the steps of
providing a first housing being comprised of a dielectric material and
having a top surface with a slot for receiving a portion of a daughter
printed circuit board and a plurality of contact chambers communicating
with the slot; inserting and mounting a plurality of a first type of
contacts in the contact chambers, the first type of contacts having a
relatively tall height in the contact chambers; inserting and mounting a
plurality of a second type of contact in the contact chambers, the second
type of contacts having a relatively short height in the contact chambers
and being located in at least some of the same contact chambers as the
first type of contacts; and inserting a separating member into the first
housing between portions of the first and second types of contacts.
In accordance with another method of the invention; a method of
manufacturing an electrical connector for mechanically and electrically
connecting a mother printed circuit board and a removable daughter printed
circuit board of the edge card type is provided. The method comprises the
steps of providing a first housing being comprised of a dielectric
material, the first housing having a top surface with a first slot for
receiving a portion of the daughter printed circuit board, a plurality of
first contact chambers communicating with the first slot, and a bottom
aperture; inserting and mounting a plurality of a first type of contacts
in the first contact chambers, the first type of contacts having a
relatively tall height in the first contact chambers; providing a second
housing being comprised of a dielectric material and having a second slot
and a plurality of second contact chambers communicating with the second
slot; inserting and mounting a plurality of a second type of contacts in
the second contact chambers, the second type of contacts having a
relatively short height relative to the first type of contacts; and
inserting the second housing, at least partially, into the first housing
bottom aperture with the first slot being aligned with the second slot.
In accordance with another embodiment of the invention an electrical
connector assembly is provided for mechanically and electrically
connecting a mother printed circuit board and a removable daughter printed
circuit board of the edge card type. The assembly comprises a first signal
section and a second power section. The first signal section has a first
elongate housing of dielectric material with a top surface having a first
slot for receiving a first portion of a daughter printed circuit board and
a first plurality of spring contacts extending into the first slot with
the first housing having a keyed end portion. The second power section has
a second housing of dielectric material with a top surface having a second
slot for receiving a second portion of a daughter printed circuit board
and a second plurality of spring contacts extending into the second slot.
The second housing has a keyed end portion such that the first and second
sections can be connected to each other at their end portions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut away partial perspective view of a high density bi-level
card edge connector incorporating features of the present invention.
FIG. 2 is a cross sectional view of the connector shown in FIG. 1.
FIG. 2a is a cross sectional view of a grounding contact separator for use
with the contacts and outer housing shown in FIG. 2.
FIG. 3 is a plan side view of a connector incorporating features of the
present invention.
FIG. 4 is a partial cross-sectional view of the signal module of the
connector shown in FIG. 2 taken from inside the card receiving slot.
FIG. 5 is a partial cross-sectional view of the power section of the
connector shown in FIG. 3 taken from inside the card receiving slot.
FIG. 6 is a partial cut away perspective view of a connector incorporating
features of the present invention with a mother printed circuit board and
daughter printed circuit board.
FIG. 7 is a cross sectional view of the connector shown in FIG. 6.
FIG. 8 are schematic bottom views of an outer housing and two different
types of inner housings.
FIG. 8a is a schematic view of the pitch of the contacts for a connector
having the outer housing and the first inner housing shown in FIG. 8.
FIG. 8b is a schematic view of the pitch of the contacts for a connector
having the outer housing and second inner housing shown in FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown a cut away partial perspective view of
a card edge connector 10 incorporating features of the present invention.
Although the present invention is being described with reference to the
embodiments shown in the drawings, it should be understood that the
present invention can be embodied in many different alternate embodiments
with any suitable size, shape, configuration or type of elements.
The connector 10 shown in FIG. 1 generally comprises a signal module 12 and
a power module 14. However, in an alternate embodiment of the invention
the power module 14 need not be provided. In addition, the signal module
12 need not have a keyed end for mating with the power module 14 as shown
in FIG. 1, but rather, may be provided as a singular form of connector as
shown in FIG. 3. In the embodiment shown in FIG. 1, the signal module 12
is generally comprised of a housing 16, a plurality of an upper or first
type of electrical contacts 18, a plurality of a lower or second type of
electrical contacts 20, and a contact separator 22. The housing 16 is
generally comprised of an electrically insulating dielectric material and
has a general elongate length with a top 24, a bottom 26, two sides 28 and
30, and two ends 32 (only one of the ends is shown in FIG. 1).
The housing 16 is a general rectangular or boxed shape member and has an
extended length largely determined by the number of contacts to be
supported therein. The majority of the bulk of the housing 16 is
essentially comprised of the parallel sidewalls 28 and 30 extending the
entire length of the housing 16. The end walls 32 are generally formed
integrally at the ends of the sides walls 28 and 30 with sufficient
thickness to add rigidity to the housing 16. Referring also to FIG. 2, a
cross sectional view of the signal module 12 is shown. The housing 16
generally comprises a slot 34 extending into the housing from the top 24.
The slot 34 extends down into the housing 16 along substantially its
entire height and is generally intended to receive a portion of a daughter
printed circuit board. In the embodiment shown, the housing 16 also has a
card stop portion 36 located at the bottom of the slot 34 extending
between the housing end walls 32 and separating walls 46 and 48 on
opposite sides of the housing 16. The card stop portion 36 is generally
intended to limit the farthest most depth of insertion of a daughter board
and, in the embodiment shown, also acts as a prestress for the lower or
second type of contacts 20. The housing 16 may also comprise intermediate
walls (not shown) between the two side walls 28 and 30 that add rigidity
to the housing 16 and also act as a polarizing means to form multiple
slots 34 in the housing 16 as is known in the art. In the embodiment
shown, the housing 16 also comprises suitable bi-level keying projections
38 for positioning different types of daughter boards at different levels
in the housing 16 when inserted such as disclosed in copending patent
application Ser. No. 07/287,765, now U.S. Pat. No. 4,934,961. Located in
the interior of the housing 16 and communicating with the slot 34 are two
rows of contact chambers 40 and 42 on opposite sides of the slot 34.
Although contacts chambers are described with reference to the embodiments
shown, it should be understood that any suitable means may be provided to
keep adjacent contacts separated from each other. Located at the top 24 of
the housing and extending down into the contact chambers 40 and 42 are
prestress portions 44 for prestressing the first type of contacts 18.
Located between and at least partially defining adjacent contact chambers
are separating walls 46 and 48 of the housing 16 which aid in keeping
contacts in one contact chamber from contacting contacts in an adjacent
contact chamber. Passing perpendicular to and communicating with the
contact chambers 40 and 42 are separator slots 50 and 52 which extend into
the housing 16 from the bottom 26. The separator slots 50 and 52 are
generally rectangular shaped, but may be slightly tapered towards their
tops. In the embodiment shown, the separator slots 50 and 52 transverse
substantially the entire length of the housing 16. However, in an
alternate embodiment each one of the separator slots 50 and 52 may be
comprised of multiple individual and separate slots. The separator slots
50 and 52 are generally intended to receive the separator 12 as will be
further described below.
As mentioned above, the signal module 12 has two types of contacts; upper
contacts 18 and lower contacts 20. The contacts 18 and 20 are generally
made of an electrically conductive material and have daughter board
contact portions 54 and 55 and mother board contact portions 56 and 57;
respectively. The upper contacts 18 have their daughter board contact
portions 54 located in a position nearer to the top of the slot 34 than
the lower contacts' daughter board contact portions 55. In the embodiment
shown, both the upper and lower contacts 18 and 20 are spring contacts
with intermediate portions 19 and 21 fixedly mounted in the housing 16
with the aid of suitable barbs or the like (not shown). The daughter board
contact portions 54 and 55 project from the contact chambers 40 and 42
into the card receiving slot 34 and are intended to be at least partially
pushed away from the slot 34 by an inserted daughter board and make
contact with conductive traces on the daughter board. In the embodiment
shown, the mother board contact portions 56 and 57 are provided as solder
tails. However, any suitable means of electrically connecting the contacts
18 and 20 to a mother board may be provided including surface mounting. As
shown in this embodiment, each upper contact 18 faces another upper
contact in an opposite contact chamber. Also in this embodiment, each
lower contact 20 faces another lower contact in an opposite contact
chamber. However, it should be understood that not every upper and lower
contact need face an opposite upper and lower contact. In the embodiment
shown, the upper and lower contacts 18 and 20 are both positioned in the
same contact chambers. Thus, for each contact chamber in the two rows 40
and 42 two contacts are housed therein; a lower contact 20 and an upper
contact 18. However, it should be understood that not every contact
chamber 40 and 42 need have both upper and lower contacts in them.
As can be seen in FIGS. 1 and 2, the separator 22, in the embodiment shown,
is a single member made of suitable dielectric material and has a first
side 58, a second side 59, two end portions (not shown) connecting the
first and second sides 58 and 59 and forming a generally open interior.
However, in an alternate embodiment of the invention, the separator 22 may
be provided as two or more separate members. The sides 58 and 59 of the
separator 22 are substantially the same cross-sectional size and shape of
the separator slots 50 and 52. In addition, the separator 22 may include
suitable means to lock the separator into place in the slots 50 and 52 and
may also be suitably shaped to act as a locking wedge when inserted into
the slots 50 and 52.
The housing and separator configuration shown in FIGS. 1 and 2 is generally
provided to perform three functions. First, it allows for relatively easy
insertion of both the upper and lower contacts 18 and 20 into the housing
16. Second, it provides an additional means of retaining the contacts 18
and 20 in the housing 16. Third, it helps to keep the upper and lower
contacts that are in the same contact chambers electrically isolated from
each other.
Generally, the method of making the signal module 12 shown in FIGS. 1 and 2
comprises first inserting the upper contacts 18 into the housing 16. Then,
the lower contacts 20 are inserted into the housing 16. Then, the
separator 22 is inserted and fixed in the separator slots 50 and 52
between the upper and lower contacts. In a preferred embodiment the
separator sides 58 and 59 have a wedge shaped cross-section and are
press-fit into the separator slots 50 and 52. However, any suitable means
can be used to fix the separator 22 to the housing 16.
Referring also to FIG. 2A, there is shown an alternate embodiment of a
separator member 22a. In the embodiment shown, the separator member 22a is
comprised of an electrically conductive member 60 having a coating of
dielectric material 62 and a plurality of solder tails 64 extending from a
bottom thereof. In addition to keeping the upper and lower contacts 18 an
20 electrically isolated from each other in the same contact chambers, the
separator 22a can also be connected to a ground in a mother printed
circuit board via its solder tails 64. Thus, although electrically
isolated from the contacts 18 and 20 because of the dielectric cover 62,
the electrically conductive member member 60 can intercept, at least
partially, electromagnetic impulses generated in the contacts 18 and 20 by
the flow of electricity therethrough and transmit the intercepted
electromagnetic impulses to the ground in the mother printed circuit board
to thereby prevent cross-talk between contacts.
The high density bi-level card edge connector described above is generally
intended for high speed applications. However, it can obviously be used
for normal speed applications also. Unlike the ordinary bi-level
connectors known in the art, wherein each contact chamber has only one
contact and, upper and lower contacts are alternatingly arranged on both
sides of the housing, the present invention nearly doubles the number of
contacts in its housing in substantially the same space as with other
connectors known in the art. Thus, the present invention can be used to
increase the number of signals being sent through the signal module 12 at
the same time due to the increased density or number of contacts. In
addition, rather than using the increased density of contacts to send more
signals at the same time along different paths, the increased number of
contacts can be used for grounding purposes with every other pair of
opposing lower contacts 20 and every other pair of opposing upper contacts
18 being connected to a ground in the mother printed circuit board. The
grounded opposing pairs of upper and lower contacts 18 and 20 could be
alternatingly arranged in the contact chambers such that only about half
of the contacts would be signal contacts and the other contacts would be
grounds. Thus, as shown in FIG. 4, the signal contacts S would have an
alternating arrangement, but with ground contacts G located above and on
both sides of the lower signal contacts S and, below and on both sides of
the upper signal contacts S.
As described above, high speed signals generate a relatively high spike of
electromagnetic impulse. The faster the signal the greater the
electromagnetic impulse. The greater the electromagnetic impulse, the
greater the possibility of magnetic forces from one contact generating a
cross-talk or interference signal in an adjacent or proximate contact. By
use of the present invention, each of the signal contacts is substantially
surrounded on two sides and either its top or bottom by grounding contacts
that intercept electromagnetic impulses and substantially prevent the
impulses from interfering with other signal contacts. Thus, substantially
faster signals can be sent through the signal module 12 without
significant increase in cross-talk between signal contacts. Since faster
signals can be sent, more signals can be sent in a given period of time
than as in old connectors thereby allowing faster communication between
the mother and daughter printed circuit boards.
The power module 14, in the embodiment shown in FIGS. 1 and 2, is similar
to the signal module 12 with various different exceptions. First, the end
32 of the signal module housing 16 has a T-shaped aperture 88. The power
module 14 has a housing 90 with a T-shaped end 92 suitably sized and
shaped to be received in the signal module T-shaped aperture 88. This use
of the mating ends of the two modules 12 and 14 locks the modules 12 and
14 together in at least two directions and suitable additional means (not
shown) may also be provided to lock the power module 14 to the signal
module 12 in all directions. FIG. 3 shows a side view of an alternate
embodiment of the invention wherein the connector 10 has an integrally
formed signal section 13 and power section 15. Referring back to FIGS. 1
and 2, the housing 90 has a card receiving slot 94 extending thereinto
from its top and suitable contact chambers 96 on both sides of the slot
94. In the embodiment shown, each contact chamber 96 has only one contact
therein with upper contacts 18 in the middle contact chambers 96 and lower
contacts 20 in the end contact chambers 96 on both sides of the upper
contacts 18. The power module 14 and the reason for this preferred
arrangement of contacts will be further described below.
Referring now to FIG. 6, an exploded partial perspective view of a mother
board 2, a daughter board 4, and an alternate embodiment of the connector
10 is shown. The daughter board 4 has two rows of contact traces on each
side; an upper row 66 and a lower row 67. This portion of the daughter
board 4 is generally intended to be inserted into the card edge receiving
slot 34 of the signal module 12. The upper row of traces 66 are aligned
with the lower row of traces 67 on the card shown, but the present
invention can also be used with daughter boards that do not have their
upper and lower rows of traces aligned as will further be described below.
The daughter board 4 also has a recess 68 to accommodate the end wall 32
of the signal module 12 when the daughter board is inserted into the
connector 10. Located at the end of the daughter board 4 is a power
section 70 having power contact strips or traces 72 on each side. In the
embodiment shown, the power contact traces 72 each have a downwardly
extending portion or tab 74.
The mother printed circuit board 2 generally includes a first plurality of
apertures 76 intended to receive the solder tails 56 and 57 of the
contacts in the signal module 12. The mother board 2 also has a second
plurality of apertures 77 intended to receive the solder tails 56 and 57
of the contacts in the power module 14. A suitable electrically conductive
plate 78 is provided on the mother board 92 interconnecting the second
plurality of apertures 77. However, it should be understood that the
present invention need not include a power module or other means to
transmit large amounts of power from the mother board 2 to the daughter
board 4.
Referring also to FIG. 7 a cross-sectional view of the connector shown in
FIG. 6 is shown. In the embodiment shown, the signal module 12 is
generally comprised of an outer housing 80, an inner housing 82, an upper
series of contacts 84 on both sides of the module and a lower series of
contacts 86 on both sides of the module. Both the inner and outer housings
are comprised of dielectric material. The outer housing 80 generally
comprises a first series of contact chambers 98 on opposite sides of the
housing 80, a center card receiving slot 100, and a cavity 102 extending
into the outer housing 80 from its bottom. The cavity 102, in the
embodiment shown, communicates with both the two rows of contact chambers
98 and the outer housing slot 100.
The inner housing 82 generally comprises a second series of contact
chambers 104, a center card receiving slot 106 that passes through a top
108 of the inner housing, and a card edge stop 110 located at the bottom
of the slot 106. The top 108 also comprises, in the embodiment shown, a
top contact prestress portion 112 and a bottom contact prestress portion
114 on both sides of the slot 106. In the embodiment shown, the outer
profile of the inner housing 82 is substantially identical to the shape of
the outer housing cavity 102 such that the inner housing 82 can be
inserted into the cavity 102 and fixedly connected to the outer housing 80
by suitable means (not shown). When the inner housing 82 is inserted into
the outer housing 80, the inner housing slot 106 aligns with the outer
housing slot 100 to form the module card receiving slot 34.
When the signal module 12 is assembled, as shown in FIG. 7, the upper
contacts 84 are at least partially housed in the outer housing contact
chambers 98 and are at least partially prestressed by the top contact
prestress portion 112. The lower contacts are at least partially housed in
the inner housing contact chambers 104 and are at least partially
prestressed by the bottom contact prestress portion 114. Both the upper
and lower contacts 84 and 86 have suitable barbs or the like to fixedly
connect them to the outer and inner housings, respectively. In a preferred
embodiment the upper and lower contacts 84 and 86 are aligned with each
other. However, as further described below, this is not a requirement of
the present invention.
The assembly of the signal module 12 shown in FIG. 7 can be accomplished in
various alternating steps, but in a preferred method of manufacturing the
signal module 12 the upper contacts 84 are first inserted into and mounted
to the outer housing 80 inside the outer housing contact chambers 98.
Then, the lower contacts 86 are inserted into and mounted to the inner
housing 82 inside the inner housing contact chambers 104. Then, the inner
housing 82 is inserted into the cavity 102 of the outer housing 80 and
fixedly mounted therein. The inner housing 82 suitably insulates the lower
contacts 86 from the upper contacts 84 and also wedges the intermediate
portions of the upper contacts 84 against the outer housing to further
secure the upper contacts 84 in the module 12.
In the embodiment shown in FIG. 6, the connector 10 has a power module 14.
However, as noted above, a power module need not be provided with the
connector. The power module 14 is generally provided to supply electricity
from the mother board 2 to the daughter board 4. The power module 14 shown
in the drawings is particularly adapted to allow for hot mating or power
active connection of the daughter board 4 into the connector 10; i.e.:
insertion of the daughter board 4 into the power module 14 when the
contacts in the power module are connected to a supply of electricity from
the mother board 2. A problem with attempting to make a connection of a
daughter board 4 to a connector actively connected to a power source in
the prior art was that arcing or jumping of electricity from the contacts
in the connectors to the daughter board would result in degradation or
distraction of the contact surfaces due to pitting and burning from the
high temperatures generated by arcing. Due to the small size of the
contacts and contact surfaces, the pitting and burning resulted in the
prevention of electrical connection between the contacts in the connectors
and the daughter board. The present invention can include a power module
as described above or unitary connector having a power section that
overcomes the problem caused by pitting and burning. Although the power
module 14 does not eliminate arcing between the contacts in the power
module 14 and the contact strip 72, the bi-level configuration of the
contacts 18 and 20 and the interconnection of the contacts 18 and 20 at
the conductive plate 78 on the mother board 2, which allows the contacts
18 and 20 to have the same electric potential, combine functions with the
power strip 72 and its tab 74 to force the arcing to occur between the
upper contacts 18 and the tab 74. This results in the lower contacts 20
and the majority of the power strip 72 not being affected by arcing
because of interconnection of the upper and lower contacts 18 and 20 at
conductive plate 78 which, once electrical connection is made between the
upper contacts 18 and the power strip 72, results in all of the contacts
18 and 20 in the power module 14 having the same electric potential as the
power strip 72 and thus no arcing occurs between the lower contacts 20 and
the power strip 72 as the daughter board is further inserted. Hence, the
power module of the present invention allows for repeated connection and
disconnection of a daughter board to a card edge connector when power to
the mother board is active. Referring to FIG. 5, a schematic
cross-sectional view of the power section 15 of the connector of FIG. 3 is
shown. In the embodiment shown, the power section is integrally formed
with the power section 13, but a section separator 116 has been inserted
into the card receiving slot to separate the contacts of the signal
section from the contacts of the power section. In the embodiment shown,
the power section 15 has one middle upper contact 18 on each side and
three lower contacts 20 on each side. However, any suitable arrangement
can be provided.
Referring now to FIGS. 8, 8A and 8B, another feature of the present
invention will be described. FIG. 8 generally shows schematic bottom views
of an outer housing 120, a first inner housing 122, and a second inner
housing 124. The outer housing 120 is similar to the outer housing 80
shown in FIG. 6, but has two series of keying slots 126 and 128, as well
as an end keying slot 130. The keying slots 126, 128 and 130 are generally
provided to ensure proper insertion and alignment of the inner housings in
the bottom aperture 102. The outer housing 120 is adapted to receive
either the first inner housing 122 or the second inner housing 124. The
first inner housing 122 has suitable keying extensions 132 and an end
keying extension 134. The keying extensions 132 are suitably positioned on
the first inner housing 122 such that when the first inner housing 122 is
inserted into the outer housing bottom aperture 102, they are received in
the second series of keying slots 128 and position the first inner housing
122 at a precise longitudinal position relative to the outer housing 120.
With the first inner housing 122 suitably positioned and mounted to the
outer housing 120, the relationship of the upper contacts 84 (see FIG. 6)
located in the outer housing 120 relative to the lower contacts 86 (see
FIG. 6) located in the first inner housing 122 can be an alignment between
the contacts as schematically shown in FIG. 8A with a pitch of about 0.05
inch between pairs of contacts, both upper and lower. The end keying
extension 134 is merely provided for polarization means to insure that the
first inner housing is not accidentally inserted into the outer housing
102 in a 180 degrees opposite orientation.
The second inner housing 124 is similar to the first inner housing 122,
except for the location of its keying extensions 132 and the longitudinal
location of its lower contacts 86 (see FIG. 6) in the second inner housing
124. When the second inner housing 124 is inserted into the outer housing
bottom aperture 102, the keying extensions 132 are received in the first
series of keying slots 126 and position the second inner housing 124 at a
precise longitudinal position in the outer housing 120. With the second
inner housing 124 suitably positioned and mounted to the outer housing
120, the relationship of the upper contacts, located in the outer housing
120, relative t | | |
