Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to cabinets ~or electrical
or electronic e~uipment.
More particularly, the invention relates to bay-
mounted cabinets, these cabinets also being known as
"wiring cubicles".
As is known, bay mounting is a mode of construction
wherein the component members of electrical or electronic
equipment are mounted on printed circuit boards carried by
supports, called "drawers" or "baskets", which can slide
on rails or slides inside a metal casing. Each drawer is
equipped with one or more electrical connectors, each
affording a fairly large number of connections. The various
elements of the device are easily accessible when the
drawers areextracted from the casing.
As will be explained in more detail hereinafter,
the wiring cubicles hitherto known are complicated in
construction and consequently inconvenient, particularly
because of the difficulties which they place in the way of
wiring operations, and they only have an insufficient
number of connections for the printed circui-t boards which
the~ contain.
An object of the invention is to provide a wiriny
cubicle which meets practical requirements better than
hitherto and which, in particular, overcomes the
disadvantages indicated above.
According to this invention there is provided a
cabinet for electrical or electronic e~uipment, comprising
a casing, a plurality of supports movable on horizontal
slides carried by lateral walls of the casing, the supports
comprising sets of further slides arranged in pairs in such
a manner that each pair of said further slides can receive
a vertically disposed printed circuit board, wherein at
least one horizontal wall of each support consists of a
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horizontally disposed printed circuit board carrying one
of the said sets of slides and havin~ lateral edges engaging
the slides carried by the casing, and wherein each of the
slides carried by the lateral walls of the casing and of
the slides carried by the or each horizontally disposed
printed circui~ board comprises a connector adapted to
receive a peripheral portion of a printed circuit board
and having contact members adapted to engage respective
conducting tracks on the peripheral portion of the printed
circuit board and means for ensuring that the contact
members are open during insertion into or extraction from
the connector of a printed circult board, the arrangement
being such that each of the connectors Eorming the slides
carried by the horizontally disposed printed circuit board
can make electrical contact with conducting tracks formed
on the peripheral portion adjacent that horizontal side of
the vertically disposed printed circuit board which engages
the slide, and the connectors forming the slides carried by
the casing can make electrical contact with conducting
tracks formed on the horizontally disposed printed circuit
board on the peripheral portions adjacent said lateral edges,
the connectors forming the slides on the horizontally
disposed printed circuit hoard being electrically connected
to the conducting tracks on that board.
The said connectors are "zero insertion force
connectors", by which is meant connectors equipped with a
mechanism which opens its contact members or allows them to
open, just before and durin~ the introduction of any
printed circuit board into the connector, and just before
and during the extraction of such a board from the connector,
that is to say to remove the active regions of the contac-t
members from the volume swept by this board in such a manner
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as to render zero the force necessary for the introduction or
for the extraction of the board and to protect the protective
coverings both of the contact members and of the connecting
tracks of the boards from any wear by friction. Once the
board has arrived in tis working position, the mechanism in
question closes the contact members or allows the~ to close,
that is to say causes them to bear resiliently, through their
active regions, on the corresponding connecting tracks of the
board, which tracks are generally provided on both faces of
the board. Such zero insertion force connectors can be
classified in three main categories: that where the
above-mentioned mechanism acts in the sense of opening the
contact members leaving these to close under the effect of
their own resilience; that thwere the mechanism in question
acts in the sese of closing the contact members leaving these
to open under the effect of their own resilience; and finally
that where this mechanism acts alternately in the sense of
opening and of closing the contact members. The first two
categories are familiar to those skilled in the art of printed
circuit boards; as for the third category,, it is illustrated,
in particular, as illustrated particularly in Canadian Patent
#1,05~,880, issued 17 April 1979 bearing title, IMPROVEMENTS
IN OR RELATING TO CONNECTING DEVICES FO~ PRINTED CIRCUIT
BOARDS AND THE LIKE of the inventor, Francois Robert BONHOMME.
Whatever the type of zero insertion force connector
which is adopted in the cabinet of the invention, the object
aimed at is, in fact, achieved. Actuallyl the connector-
slides carried by the casing enable the number of outlets of
the circuits to be increased while the connector-slides
carried by horizontally disposed printed circuit boards,
facilitate the wiring operations.
It will be apparent that the extended possibi:Lities
of design which are offered by the equipment
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according to the invention enable numerous electrical
connectors, which facilitate the establishment o~ verv
numerous outlets for electrical circuits, to be accommodated
in the smallest space, and this without using a mechanism
requiring great precision, the usual rigid drawer being
essentially replaced by a horizontally disposed board guided
in two rows of zero insertion force conne~tors.
Each support may advantageously comprise a single
horizontally disposed printed circuit board and a set of
board guides each positioned in the same vertical plane as
a respective one of the connectors forming the slides
carried by the horizontally disposed printed circuit board
and adapted to receive the edge of a vertically disposed
printed board opposite the edge received by the connector.
Each board guide is preEerably fixed directiy to the
associated connector on the horizontally disposed board.
Those casing vertical walls comprising zero
insertion force connectors as slides for said horizontally
disposed printed circuit boards preferably consist of
printed circuit boards.
The invention also includes a printed circuit
board for use in a cabinet as defined above, wherein the
board is ~rovided on at least one its faces with a series
of parallely-extending zero insertion force connectors.
The invention will now be described, by way of
example, with reference to the accompanying drawings, in
which :
Figure 1 shows, in exploded perspective view, the
essential elements of a prior art wiring cubiclei.
Figure 2 shows, in a similar manner to Figure 1,
the essential elements of a wiring cubicle which is
constructed in accordance with one of the preferred
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embodiments o~ the invention.
~ igure 3 shows, in perspective view with cut-
away portions, the main components of a wiring cubicle which
is constructed according to a second preferred embodiment
o~ the invention.
~ igure 4 shows in front view the wiring cubicle
of ~igure 3, represented at a smaller scale.
Figure 1, illustrating the prior art~ is provided
so as to make the novelty and the advantages of the
invention more apparent.
According to the known construction shown in
Figure 1, the casing 1 of the cabinet comprises three
vertical walls conne~ted at right angles, that is to say a
rear wall 2 and two lateral walls 3 t only one of which is
illustrated. ~long each lateral wall 3, the casing 1 carries
a plurality of superimpos~d sets o two horizontal slides,
each set comprising a lower slide 4 and an upper slide 5.
On the two symmetrical lower slides 4 and on the two
symmetrical upper slides 5 there can slide a rigid drawer 6
which generally comprises a horizontal lower wall 7, a
horizontal upper wall 8, a vertical transverse wall 9 and
two vertical lateral walls 10 ; these lateral walls 10,
only one of ~hich is illustrated, are parallel to the
lateral walls 3 o-f the casing 1. Tongues 11 and 12 project
from each vertical lateral wall 10 of the drawer 6 to
engage respectively in the slides 4 and 5. The horizontal
walls 7 and ~ of the drawer 6 have slides or guide grooves
13 and 14 which open towards one another in pairs in such a
manner that each pair of grooves 13 and 14 can receive
vertically a ~rinted circuit board 15 which, apart from
electrical or electronic components, carries conducting
connection tracks 16 onlv on its rear vertical edge (that
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is to say the vertical edge ~irst engaged in the grooves 13
and 1~ hen each board 15 is completely introduced into
its drawer 6, its tracks 16 touch resilient contact members
(not shown) which belong to a connector 17, the connectors 17
which correspond to the various boards 15 being carried by the
vertical transverse wall 9 which constitutes the back of the
drawer 6. The contact members of these connectors are connected
by wires ~not shown) to the terminals of a multiple connector
(male or female) 18 which is likewise carried by the vertical
transverse wall 9 of the drawer and which co-operates with
a matching multiple connector 19. At the height of each
drawer 6, the casing 1 carries such a matching connector 19 on
its rear vertical wall 2 which constitutes the back of the
casing 1.
As it has just been described, this known wiring
cubicle generally gives satisfaction but its mechanical
construction is complicated and it is consequently expensive.
Moreover, all the electrical connections emerge solely
through the back wall 9 of the drawers 6 and through the
back wall 2 of the casing 1 ; this is why, in many
applications these electrical connections are insufficient
in number in relation to the electrical circuits which are
contained or could be contained in the printed circuit
boards 15.
It is order to overcome these disadvantages
that the wiring cubicle according to the invention has been
created, a first preferred embodiment of which is illustrated
in Figure 2.
As shown in Figure 2, the casing comprises three
vertical walls ~not illustrated) in the usual manner, which
are generally fixed to four uprights 20. Along each of its
latexal walls, the casing carries horizontal slides each
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consisting of one or more aligned zero insertion force
connectors 21. These connectors 21 have a ~-shaped section
and are disposed in pairs at the same height, the connectors
of each pair opening towards one another. ~ support 22, -the
lower wall of which consists of a horizon-tally disposed
printed circuit board 23 (hereinafter called the "mother
board"), can slide on the two connector-slides 21 of each
pair. The width of this mother board 23, that is to say its
hori~ontal dimension measured at right angles to the
direction of introduction and e~traction which is represented
by an arrow F, is only sligh-tly less than the distance
between the bottoms of the two connectors-slides 21. On its
two edges parallel to the direction F, each mother board 23
has connecting tracks 24 which touch the contact members
(not shown)of the connector-slides 21 when these contact
members are closed on the principle referred to above.
Parallel to the direction F, the mother board 23
carries slides which consist of zero insertion force
connectors 25. These connectors 25 have a U-shaped section
and their contact members are permanently connected to the
printed circuits o~ that mother board 23 carrying said
connectors 25. A board guide 26l in the form of a gallows,
is fixed, in the same mean vertical plane as each connector-
slide 25, either preferably to this connector-slide 25, or
to the mother board 23. On its upper horizontal branch, the
board guide 26 has a groove 27 which plays the same part as
each groove 14 in Figure 1. It is thus possible to insert,
through the front face of the casing, inside each groove 27
and the subjacent connector-slide 25, a vertically di.sposed
printed circuit board 28 (a "daughter board") which differs
from the board 15 of the known apparatus of Figure 1 in that
its connecting conducting tracks 29 are disposed, not on its -
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rear edge, but on its lower hori20ntal edge.
Thus a wiring cubicle is obtained, the mode oEassembly of which is as follows. The connec-tor-slides 21
are first mounted by connecting the tails 30 of their
contact members to the usual insulated outlets of the wiring
cubicle ; then, after these contact members have been opened,
the complete support 22, that is to say the mother board 23,
equipped with the board guides 26 and with the connector-
slides 25, the tails of the contact members of which are
connected to the lateral tracks 24 oE the mother board 23,
is introduced as far as it will go, in the direction of the
arrow ~, after which the said contact members are closed.
Then, after the contact members of the connector-
slides 25 have been opened, as many daughter boards 28 as
necessary are fully introduced into each of these latter
connector-slides, by engaging their horizontal edges in one
of the connector-slides 25 and in the groove 27 which is
associated with the slide, after which the contact members
of these connector-slides 25 are closed.
If it is desired to remove a daughter board 28 to
check it or to replace it with another, it is sufficient to
open the contack members of the corresponding connector-
slide 25 to release it and so permit its extraction in the
opposite direction to that oE the arrow F.
In a m~dification (not illustrated) of the
described embodiment, each board guide 26 is replaced by an
upper connector-slide symmetrical with one oE the lower
connector-slides 25, and all the upper connector-slides are
fixed to a second mother board symmetrical with the mother
board 23, the two mother boards then possibly being
mechanically connected to one another, for example b~ means
of ver-tical walls similar -to the walls 9, 10 of the known
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apparatus shown in Figure 1. In this case, of course, it is
necessary to associate with the second mother board (not
illustrated), two connector-slides similar to those which
are designated by reference numeral 21 and carried at the
required height by the casing.
According to the embodiment shown in Fiyures 3
and 4, the casing of the cabinet comprises three vertical
walls, that is to say two lateral walls which will be
referred to below and a rear wall 31. These vertical walls
are generally fixed to four uprights 40. Along each of its
lateral walls, the casing carries horizontal slides each
consisting of one or more aligned zero insertion force
connectors 41. These connectors 41 have a U-shaped section
and are disposed in pairs at the same height, the connectors
of each pair opening towards one another. There has been
represented diagrammatically in Figure 3 a control member
32, either sliding or rotating, which enables opening and
closing all electrical contact members of a connector 41 or
of like aligned connectors.
A support which consists of a printed circuit
mother board 43 can slide on the connector-slides 41 of
each pair. The width of this mother board 43, that is to say
its horizontal dimension measured at right angles to the
direction of introduction and extraction which is represented
by an arrow F in Figure 3, is only slightly less than the
distance between the bottoms of the two connector-slides 41.
On its two edges parallel to the direction F, each mother
board 43 has connecting tracks (not shown) which touch the
contact members (not shown) of connector-slides 41 when these
contact members are closed on the principle referred to
above.
Parallel to the direction F, each mother board 43
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carries slides which consist of zero insertion force
connectors 45 the contact members of which are permanently
connected to the printed circuits of said mother board 43.
The connectors ~5 may be provided either on one of the
sides only of mother boards 43, as shown in Figure 3 or as
represented on the three lowermost mother boards ~3 of
Figure 4, or on both sides of mother boards 43, as
represented on the two uppermost mother boards 43 of Figure
4. These connectors 45 have a U shaped section and are
disposed in pairs in the same vertical plane parallel to
direction F, the connectors 45 of each pair opening towards
one another. Inside the connectors 45 of such a pair, it is
thus possible to insert, from the front face of the casing,
a printed circuit daughter board 48 which is ~rovided with
conducting tracks for cooperating with the contact members
of connectors 45 respectively. Atthe upper part of Figure
4, there are shown daughter boards 48 whose lower edges only
engage the connectors 45 carried by the underlying mother
b~ard 43. In this event the upper edges of these daughter
boards are guided by grooves in board guides which may be
fixed to said underlying mother board, in the manner
disclosed with reference to Figure 2.
The cabinet which has just been described is thus
far similar to that of the precediny embodiment.
According to the embodiment of Figures 3 and 4,
those vertical lateral walls of the casing which comprise
zero insertion ~orce connectors 41 as slides for mother
boards ~3 consist of printed circuit boards 33 (herein-
after called "grandmother boards"), the contact me~bers of
connectors 41 being permanently connected to the printed
circuits of said grandmoth~r boards 33. Depending on the
height of the casing, each vertical lateral wall of the
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casing may consist either of one grandmother board 33, or
of at least two grandmother boards which are superimposed
and electrically connected to each other~
Uprights 40 are provided with securing holes 34
which are spaced a constant distance or "modulus" apart,
along the height of these uprights, and each grandmother
board 33 is provided with securing holes 35 vertically
spaced apart a length equal to this "modulus" or to a
multiple thereof, a pin 36 being inserted in each pair of
registering holes 34, 35.
The cabinet thus comprises three sets o printed
circuit boards :
1) two vertical grandmother boards 33 provided
with printed circuits 37 for making connections between at
least two mother boards 43 ;
2) two or generally more than two horizontal
mother boards 43, provided with printed circuits (in general
on both sides) or making connections between at least two
daughter boards 48 ;
3) a plurality of vertical daughter boards 48,
parallel to grandmother boards 33, which daughter boards
carry the conventional electric and electronic components
(capacitors, resistors, transistors, etc.) on either or both
sides.
It is not excluded ho~7ever that mother boards 43
and qrandmother boards 33 also carry some com~onents nor
that some dauqhter boards 48 carry(on eitheror both sides)
connecting printed circuits such as circuits 39, as a
complement or a substitute to electric or electronic
componentsO
~ ccording to the embodiment of Figure 3 and 4,
it is possible to make in advance all the electrical
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connections, during the production of the various printed
circuit boards 33, 43, 48 by using conventional technlques.
There is no difficulty in attaching connectors 41 and 45
respectively to boards 33 and 43 and in piercing holes 35
in ~oards 33.
As these printed circuitboards and the frame 31,
40 of the cabinet are supplied to the assemblers, they have
only to proceed as follows :
- fixing the grandmother boards 33 to the frame ;
- inserting mother boards 43 in connector-slides 45 and
closing the contact members of said connector-slides ;
- connecting feed conductors 52 to one or several
connectors 51 provided at the lower portion of grandmother
boards 33, these connectors 51 being plain connectors or
zero insertion force connectors.
Because of the great number of electrical
conneations which may be made between the various levels
of the cabinet through the printed circuits 37, 39 of
grandmother boards 33 and daughter boards 48, simple printed
circuit boards can be used instead of, as usual, multilayer
boards which are very expensive.
On the other hand the present invention allows :
- to dispense with the drawers or baskets of conventional
cabinets ;
- to shorten the electrical path between ~he various
circuits, which is particularly significant for application
to computers where the travelling times of electrical
pulses are to be taken into account ;
- to dispense with all the wiring operations proper and
conse~uently to prevent any mistakes being made during
such operations ;
- to permit of changing connections after assembling,
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either by suhstituting a modified board to one of
boards 33, 43 or by cancelling a printed connection, in
particular one of the printed connections 37a of a
grandmother board 33, and replacing it by a conductor
wire 53 which is subsequently soldered to circuits of
the board.
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