Electrical signal transmission equipment bay

An electrical signal transmission equipment bay, comprising a number of ingoing and outgoing cables (81, 15) which are connected, by means of relevant row connectors (79) and coaxial connectors (61) to signal processing boards (19, see FIG. 3) contained in the functional units (25). The coaxial connectors (61) are prepositioned during mounting in openings (59) of a displaceable mounting beam (47) which is subsequently secured to a positioning plate (35) which comprises openings (63) wherethrough the coaxial connectors (61) are inserted. Subsequently the positioning plate (35) is rigidly connected to the supporting beams (1, 3) in the bay. The bay is particularly suitable for use in telephone exchanges. (FIG. 2).

The invention relates to an electrical signal transmission equipment bay, 
comprising two parallel supporting beams wherebetween cable guide beams 
extend which are directed transversely of the supporting beams and which 
are situated in a first vertical plane, and also cables, going into and 
out of the bay, which are guided along the cable guide beams and which 
extend mainly parallel to the supporting beams inside the bay, the ends of 
a number of said cables being provided with a row connector for electrical 
connection to one of a number of plug-in signal processing boards, each 
accommodated in one of a number of functional units accommodated in the 
bay, via successively a row connector which is situated on a positioning 
plate for the respective functional unit, a master printed wiring board 
which is connected to the positioning plate, and a further row connector 
which is connected to the positioning plate and into which that signal 
processing board is plugged. 
In a known bay of the described kind (Philips Telecommunication Review, 
Vol. 33, No. 3, September 1975, page 145), the positioning plate is 
provided with row connectors for so-called low-frequency ingoing and 
outgoing station cables, as well as with row connectors for low-frequency 
connections between the signal processing boards in a functional unit. As 
a result of the miniaturization of the signal processing boards, the 
number of signal processing boards per functional unit has increased and 
hence also the number of ingoing and outgoing station cables. The space 
between the cable guide beams and the positioning plate is thus occupied 
by ingoing and outgoing cables to such an extent that the accessibility of 
the cable ends provided with connectors is more different, and also the 
movability of the cable ends is substantially decreased. This movability 
and accessibility should be optimum for suitable connection of the 
connectors to the positioning plate in the comparatively small working 
space. 
The problem concerning the connection of connectors has become still more 
significant since now, in addition to the low-frequency cables, use is 
also made of high-frequency cables of the coaxial type whose cable ends 
are provided with coaxial connectors. These coaxial connectors are to be 
secured on the positioning plate on which a connection is established with 
mating coaxial connectors provided on the signal processing boards. 
Because the so-called plugging tolerance of coaxial connectors is 
substantially smaller than the plugging tolerance for row connectors (in 
the low-frequency part of the positioning plate), it is difficult in the 
available small height working spaces between already mounted functional 
units to align the coaxial connectors on the cable ends so that their 
centres coincide with the centres of the mating coaxial connectors on the 
signal processing boards. 
The invention has for its object to provide a bay in which the alignment of 
the coaxial connectors and mating connectors is facilitated, whilst said 
connectors are also readily accessible at the same time. 
To this end, the invention is characterized in that between the supporting 
beams there is provided at least one mounting beam which extends 
transversely of the supporting beam and on which are positioned a number 
of coaxial connectors each connected to the end of one of the cables, said 
coaxial connectors cooperating, via a number of openings in said 
positioning plate, with a number of mating coaxial connectors which are 
provided on the signal processing boards in the respective functional 
unit, said mounting beam being adapted for detachable suspension from the 
supporting beams during the positioning of said coaxial connectors on the 
mounting beam, and being adapted for subsequent rigid connection to the 
positioning plate prior to rigid connection of the positioning plate to 
the supporting beams. 
Because the mounting beam prealigns the coaxial connectors with respect to 
the apertures in the positioning plate, suitable mounting of the 
positioning plate is possible, followed by easy mounting of the signal 
processing boards in the functional units. 
In order to prevent accurate positioning of the hole pattern in the 
positioning plate with respect to the hole pattern in the mounting beam 
from increasing the cost during the punching process, a preferred 
embodiment of the bay is characterized in that the mounting beam as well 
as the positioning plate is provided with openings through which the 
coaxial connectors are inserted with clearance.

The prior art bay shown in FIG. 1 comprises two metal supporting beams 1 
and 3 which extend parallel to each other and which have an L-shaped 
transverse profile, said beams being secured to relevant vertical columns 
5 and 7 which form a lateral as well as a rear boundary of the bay. 
Between the supporting beams 1 and 3 there are provided a number of 
horizontal cable guide beams 9 which comprise brackets 11 and pins 13 for 
guiding station cables 15 going into and out of the bay and so-called 
internal cables 17 which inter alia serve for the power supply of signal 
processing boards 19 (only one signal processing board is visible.) The 
cables 15 and 17 extend mainly parallel to the supporting beams 1 and 3 
and are uniformly distributed over the entire width of the bay when the 
bay is fully occupied. The cables 15 are provided near their ends with row 
connectors 21 of a customary type, whilst the cables 17 are provided near 
their ends with row connectors 23 which are also of a customary type. The 
row connectors 21 and 23 of a section of the bay which is not yet occupied 
by a functional unit 25 are connected for the time being to a horizontal 
parking beam 27 screwed onto the supporting beams 1 and 3. Before a 
section of the bay is occupied by a functional unit 25, the relevant row 
connectors are detached from the relevant parking beam. In the present 
case, a section which is situated underneath the parking beam 27 is 
occupied. To this end, inter alia relevant row connectors 29 are detached 
from a parking beam 31 and are subsequently inserted through a window 33 
in a metal positioning plate 35. On the positioning plate 35 there are 
provided row connectors 37 whereto the row connectors 29 are connected. 
The positioning plate 35 is secured to the supporting beams 1 and 3 only 
after all relevant, previously parked row connectors have been inserted 
through the relevant windows of the positioning plate. Subsequently, these 
connectors are connected to the relevant row connectors on the positioning 
plate. 
The functional unit 25 is mounted on the positioning plate 35 after the 
positioning plate 35 has been mounted on the supporting beams 1 and 3. The 
functional unit can then be filled with a number of signal processing 
boards only the signal processing board 19 thereof being shown for the 
sake of simplicity. The functional unit 25 comprises guides 39 for the 
sliding and plugging of the signal processing boards 19. The signal 
processing boards 19 comprise a printed wiring board on which a number of 
electrical components are mounted for the processing of electrical 
signals. In the present case, concerning bays intended for telephony, said 
components act on speech signals. On the positioning plate 35 a row 
connector 41 is provided for each signal processing board 19. The signal 
processing boards 19 are provided with a known plug section (not shown) 
which is inserted into the row connectors 41. On the rear of the 
positioning plate 35 there is provided a master board 43 which is mounted 
on the positioning plate and which is provided on both sides with printed 
wiring and also with plated-through holes. All row connectors (37 and 41) 
mounted on the positioning plate 35 comprise connection pins which are 
inserted, through openings in the positioning plate 35, into the 
plated-through holes of the master board 43. The electrical connection of 
these connection pins to the master board 43 is realized in one operation 
by wave-soldering before the mounting of the positioning plate 35. The 
master board 43 comprises recesses 45 for inserting the row connectors 29. 
Due to the use of coaxial cables which are suitable for high frequencies 
and whose ends are provided with coaxial connectors, these coaxial 
connectors must be inserted through openings in the positioning plate for 
electrical connection to mating coaxial connectors provided on the signal 
processing boards 19. Contrary to row connectors, these coaxial connectors 
and mating connectors must be very accurately aligned in order to prevent 
damaging of the contact pins and the contact sockets. During the mounting 
of the positioning plate 35 on the supporting beams 1 and 3, however, 
hardly any space remains behind the positioning plate 35 for the 
maneuvering of the coaxial connectors. In the bay in accordance with the 
invention which is described hereinafter, the problem described with 
reference to the prior art bay is solved. The parts of the bay in 
accordance with the invention which correspond to the prior art bay are 
denoted by corresponding reference numerals (FIG. 1) and are not 
elaborated for the sake of brevity. 
The coaxial part of the station cables going into and out of the bay shown 
in FIG. 2 is shown at the left. Underneath the parking beam 31 there is 
provided a horizontal mounting beam 47 of sheet metal (for example, 
steel). In the case of a plurality of sections which correspond to a 
plurality of functional units 25 of a bay, there is a repetitious pattern 
of mounting beams extending between two parking beams. For example, a 
mounting beam 49 is situated between the parking beams 27 and 31. The 
mounting beam 47 is bent at right angles twice near its left as well as 
near its right end, so that ears 51 and 53 are formed. In each of the ears 
51 and 53 there is provided a recess 55, so that the mounting beam 47 can 
be loosely suspended from pins 57 screwed into the supporting beams 1 and 
3. The size of the recess 55 and the diameter of the pin 57 are matched so 
that the mounting beam 47 can be shifted to the left as well as to the 
right and upwards and downwards with respect to the pins 57. Preferably, 
use is made of a pin in the form of a so-called shouldered bolt (bolt 
comprising a head and an abutment shoulder) which is screwed into the 
supporting beams 1 and 3 only so far that the ears 51 and 53 can still be 
slid forwards and backwards between the said head and the supporting beams 
1 and 3. Obviously, the mounting beam 47 can be suspended in a 
displaceable manner from the supporting beams 1 and 3 in a variety of 
ways. The described method, utilizing the ears 51 and 53 which are formed 
by bending at right angles twice, offers the advantage that the ears 51 
and 53 also provide adequate space for the cables behind the mounting 
beam. After having been suspended, the mounting beam 47 can thus be tilted 
and slid in all directions. The mounting beam 47 is provided with a 
regular pattern of holes 59. The ends of the coaxial cables 15 are 
provided with coaxial connectors 61 which can be inserted through the 
holes 59 with a clearance. In the lower part of the positioning plate 35 
there is provided a pattern of holes 63 which corresponds to the pattern 
of holes 59 in the mounting beam 47. When the positioning plate 35 is 
mounted, the coaxial connectors 61 also project with a clearance through 
the holes 63 in the positioning plate 35. Coaxial connectors 65 which mate 
with the coaxial connectors 61 are mounted on the signal processing boards 
19 (see FIG. 3) by means of L-shaped strips 67 which are secured on the 
signal processing boards 19. A coaxial connector 61 and the mating coaxial 
connector 65 is provided for each coaxial connection 69, the details of 
which will be described with reference to FIG. 9. 
The FIGS. 2, 3 and 5 clearly show that the positioning plate 35 is 
subdivided into three sectors. Proceeding from the bottom upwards, there 
is provided a first sector which comprises the pattern of holes 63 for the 
coaxial connectors 61 which form coaxial connections 69 (see FIG. 9) in 
conjunction with the mating coaxial connectors 65 (see FIG. 3), said 
connections 69 being present in the coaxial station cables 15 going into 
and out of the bay. The coaxial connections 69 are usually installed at 
the site of a bay, so that the accessibility of these connections must be 
optimum for mounting. Above the pattern of holes 63 there is provided a 
further pattern of holes (not shown in FIG. 5 for the sake of simplicity) 
for inserting coaxial connectors 71 which are connected to mating coaxial 
connectors 73 which are provided on the L-shaped strips 67 of the signal 
processing boards 19. The coaxial connectors 71 and the mating coaxial 
connectors 73 together form coaxial connections of the same type as the 
coaxial connections 69 (see FIG. 9) and are used for interconnecting the 
signal processing boards 19 of the same functional unit 25. This is 
realized by means of coaxial cables 75 (see FIG. 3) which extend 
substantially horizontally behind the positioning plate 35. In FIG. 3, the 
coaxial cables 75 have been turned one quarter of a turn in order to make 
them visible. The third and upper section of the positioning plate 35 is 
occupied by the low-frequency row connectors 41 in which the signal 
processing boards 19 are plugged by way of row connectors 77 if present. 
The row connectors 41 are connected, via the master board 43 (see FIG. 3), 
to the row connectors 37 which are also situated in the third section. The 
row connectors 37 are connected, by way of row connectors 79 (see FIG. 2) 
inserted through the windows 33, to cables 81. The cables 81 serve for 
low-frequency connections going into and out of the bay. The cables 81, 
however, may also include cables for low-frequency connections between the 
signal processing boards 19 of one and the same functional unit (for 
example, the cables 17 in FIG. 1). 
The coaxial connectors 61 are mounted on the mounting beam 47 before the 
mounting beam 47 is suspended from the pins 57, so that optimum 
accessibility and maneuverability of the connectors is obtained. This is 
also partly due to the fact that the height (in the vertical direction in 
the mounted condition) of the mounting beam 47 is substantially smaller 
than the height of the positioning plate 35 which is to be mounted at a 
later stage. After all coaxial connectors 61 have been secured on the 
mounting beam 47, the beam is suspended from the pins 57. Because the 
positioning plate 35 itself is aligned again with respect to the mounting 
beam 47, the coaxial connectors 61 have thus been prealigned with respect 
to the pattern of holes 63 in the positioning plate 35. Because the 
functional unit 25 itself is aligned again with respect to the positioning 
plate 35, the coaxial connectors have also been prealigned with respect to 
the mating coaxial connectors 65 which are situated on the signal 
processing boards 19 which are to be slid into the functional unit 25 at a 
later stage. The alignment of the positioning plate 35 with respect to the 
suspended mounting beam 47 is realised by means of alignment tags 83 and 
85 which are formed on the mounting beam 47 and which fit in relevant 
holes 87 and 89 provided in the positioning plate 35 (see FIGS. 2 and 5). 
A third alignment tag 91 of the mounting beam 47 fits in a hole 93 of the 
positioning plate 35. After alignment of the positioning plate 35 with 
respect to the mounting beam 47, the mounting beam which is still movably 
suspended from the pins 57 is screwed to the positioning plate 35. This is 
effected by means of at least two screws 95 and 97 which are screwed into 
threaded holes in the mounting beam 47. Only one threaded hole 99 is 
visible in FIG. 2. The alignment of the functional unit 25 with respect to 
the positioning plate 35 is realised by means of an alignment tag 101 
which is punched from the positioning plate 35 and which fits in a slot 
102 formed in the bottom plate of the functional unit 25. After the 
positioning plate 35 has been secured to the mounting beam 47, the 
positioning plate 35 is screwed to the supporting beams 1 and 3 by means 
of screws 103 which are secured in the positioning plate 35 at the left 
(not visible) as well as at the right and which are prevented from falling 
out of the positioning plate 35 by means of threaded bushes 105 which also 
determine the distance between the positioning plate 35 and the supporting 
beams 1 and 3. Subsequently, the functional unit 25 is screwed to the 
positioning plate 35, after which the signal processing boards 19 are 
inserted into the functional unit 35. Simultaneously per signal processing 
board 19, the row connectors 77 are connected to the row connectors 41, 
the mating coaxial connectors 73 are connected to the coaxial connectors 
71, and the mating coaxial connectors 65 are connected to the coaxial 
connectors 61 (see FIG. 3). 
In order to prevent the extremely small manufacturing tolerances of notably 
the positioning plate 35 and the mounting beam 47 from having a 
cost-increasing effect, a given clearance is provided between the coaxial 
connectors 61 and the holes 59 and 63 in the mounting beam 47 and the 
positioning plate 35, respectively. This clearance is denoted by the 
reference numeral 107 for the positioning plate 35 and by the reference 
numeral 109 for the mounting beam 47 in FIG. 9. In principle, the 
clearances 107 and 109 may be the same. Obviously, said clearances are 
also attuned to the permissible plugging tolerance of the coaxial 
connectors. The coaxial connection 69, formed by the connection of the 
coaxial pin connector 61 to the coaxial socket connector 65 as well as by 
the bushes 110 and 112 is of a customary construction. However, of 
essential importance are the clearances 107 and 109 for the outer parts of 
the connection which project through the positioning plate 35 and the 
mounting beam 47. It is also to be noted that, after the said connection 
has been established, it is not necessary to eliminate the lateral 
slidability in the holes 63 and 65 by the tightening of a nut 111 and a 
spacing bush 113. It is sufficient to lightly tighten the nut 111 and the 
bush 113. 
The increased data flow per cable and the increased miniaturisation of the 
electrical components on the signal processing boards 19 have given rise 
to a greater development of heat than previously in the functional units 
25. Because the signal processing boards 19 are vertically arranged in the 
functional units 25 (see FIG. 1) and because the functional units 25 are 
provided with circulation apertures 115 (see FIG. 10), use can be made of 
the natural draught of heated air. If necessary, this natural draught can 
be supplemented by forced cooling. Forced cooling of this kind, however, 
is not necessary in a considerable number of cases, if, like in a 
preferred embodiment of the described bay, use is made of a roof-shaped 
guiding device 117 which is mounted each time between two functional units 
25 and which serves as a cooling device. The comparatively cold air 
entering in accordance with the arrows 119 can rise between the signal 
processing boards 19 (not shown for the sake of simplicity) according to 
the broken lines 121, and can escape according to the arrow 125 through a 
window 123 in the guiding device 117. 
It will be clear that the bay in accordance with the invention is not 
restricted to a given type of cable such as said coaxial cables. 
Fibre-optic telecommunication cables presently being developed can also be 
advantageously used in the described bay. The alignment of the likewise 
coaxial connector parts is of major importance for such a type of cable.