AU593667B2

AU593667B2 - Sub-rack arrangement

Info

Publication number: AU593667B2
Application number: AU75316/87A
Authority: AU
Inventors: Samuel Dean
Original assignee: Standard Telephone and Cables Pty Ltd; Standard Telephone and Cables PLC
Current assignee: Nokia Services Ltd
Priority date: 1986-07-17
Filing date: 1987-07-07
Publication date: 1990-02-15
Anticipated expiration: 2007-07-07
Also published as: AU7531687A

Description

593667 0 8 V 0 0 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-1969 COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED "SUB-RACK ARRANGEMENT" The following statement is a full description of this invention, including the best method of performing it known to us:- This invention relates to a sub-rack arrangement for mounting plug-in circuit boards, particularly, though not exclusively associated with teleconmmunications equipment.

Sub-rack arrangements of the aforementioned kind are normally mounted in a vertically stacked manner on a rack with the station cable usually entering the from one side. The conductors of the station cable are then coupled via wires or conductive tracks to elements of a connector which mates with an edge connector on a plug-in circuit board.

In a known sub-rack arrangement, conductors of the station cable are terminated on a terminal array located on the front edge of a top shelf of the sub-rack. The top shelf comprises a circuit board whose conductive ft o 0 tracks connect contact elements of the terminal array to conductive tracks So of a back plane circuit board, the conductive tracks of the back plane circult board being connected to contact elements of connectors which mate with edge connectors on plug-in circuit boards. The plug-in circuit boards are cooled by a thermal plenum located at the bottom of the sub-rack.

The known arrangement, though satisfactory, is relatively expensive, particularly the top shelf assembly, and requires space for the thermal plenum. It is an object of the present invention to provide a sub-rack arrangement of a simple and inexpensive construction which does not require a top shelf to support the terminal array nor does it require a thermal plenum.

It is a further object of the present invention to provide an optical coupler mounting arrangement which prevents damage to optical cable coupled to a plug-in circuit board.

According to the invention there is provided a sub-rack arrangement ih i for electronic equipment, comprising a first wall member and a second wall member disposed in a fixed parallel spaced relationsiip and joined by two side wall members to define a space, said space being divided into a first compartment and a second compartment by a shelf member extending between 2

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said side wall members and lying in a plane substantially parallel to the plane of the first wall member and the second wall member, said first compartment being defined by at least the first wall member and the shelf member. and the second compartment being defined by the second wail member and the shelf member, and a rear panel incorporating a plurality of conductive tracks thereon, said rear panel being disposed in a plane substantially normal to the planes of said wall members and forming the rear wall of the first compartment and the second compartment, wherein said first wail member and said shelf member are provided with guide member means on interfacing sides thereof for slidably eceiving and supporting a first pair of opposite edges of at least one demountable circuit board provided with a first mateable Connector means mounted proximate an edge thereof, which edge is substantially normal to said first opposite edges, and wherein the o 0 rear panel of said first compartment has mounted thereon at least one seco *0 ond mateable connector means for mating with said first mateable connector o means of a supported circuit board, the rear panel of said second compartment having mounted thereon at least an array of terminal means contacts of which are connected to contacts of said second mateable connector means via Sconductive tracks on said rear panel.

26' In order that the inven~lon may be readily carried into effect, an embodiment thereof will now be described with reference to the drawings in :~:which: p. Fig. 1 is a perspective view of a sub-rack incorporating the present Sinvention, Fig. 2 is a perspective view of a front cover arrangement for the subrack shown in Fig. 1, Fig. 3 shows an optical coupler element mounting arrangement for mounting an optical coupler element on a plug-in circuit board, Fig. 4 shows details of part of the top shelf of the sub-rack of Fig.

13 ToA' Fig. 5 is a plan view of a preferred top shelf arrangement.

Referring to Fig. 1, the sub-rack 1 comprises an open fronted generally box-shaped metal housing approximately 4 40mm wide x 330mrm high x 250mm deep, including a bottom wall 2, a back wall 3, two side walls 4, and a top wall 5. Attached to back wall 3, but spaced therefrom is a fibre glass panel 6. Panel 6 incorporates conductive tracks (not shown) on both major surfaces thereof. The interior of housing 1 is divided into an upper and a lower section by a shelf 8 made rigid by a flange 9 along each edge of the shelf. The rear edge flange is provided with four studs 10 (see Fig. 4) whereby panel 6 can be attached to flange 9 to increase the rigidity of panel 6. Shelf 8 and bottom wall 2 are each provided with two parallel *.linear arrays of closely spaced holes 12 and 13 whose diameters are such Sthat they co-operate with resilient tabs (not shown) on circuit board guide rails 14, with which the guide rails are detachably mounted. One side wall 4 is provided with an aperture 15 through which office cable (not shown), I fit including optical fibres, may enter the top section of the housing. The opposite side wall may also be provided with a similar aperture. Bottom wall 2 is provided with two tongues 16 extending outwardly from the corners formed with the side walls 4 and lying in the same plane as bottom wall 2.

Tongues 16 slidably co-operate with grooves 17 (see Fig. 2) to slidably retain front cover 18 at least partly below bottom wall 2 when access to the h-ousing is required. To close the housing, front cover 18 is slidably wihrwnutl igemas 9c-operates with studs 20, only one of which ftis shown, whereupon the front cover can be swung upwards to close the housing. A latch means (not shown) latches the front cover in place. Frontjj' cover 18 is provided with two spaced arrays of ventilation holes 21 and 22 for ventilation of the housing when it is closed.

That part of the fibre glass panel 6 located in the upper section of housing 1 is provided with a plurality of cable conductor terminal means 23 3dY two only being shown, whose contact elements (not shown) are connected to C) 4 conductive tracks on panel A plurality of co-axial connector sockets 24~, two only being shown, are also mounted on panel 6 in the upper section.

The contact elements (not shown) of connector sockets 24~ are connected to conductive tracks on panel 6. Preferably, terminal means 23 are in the form of insulation displacement terminals. That part of fibre glass panel 6 located in the lower section of housing 1 is provided with a plurality of connectors, one only, 25, being shown. Contact elements of connector are connected to contact elements of terminal means 23 and connector sockets 214 via conductive tracks. Connector 25 mates with an edge connector of a plug-in circuit board (not shown) slidably supported in guide rails 114.

A preferred feature of the present invention is the provision of an 0 0 arrangement which prevents damage to optical fibres coupled to the plug-in ~:circuit board via optical couplers. When one or more optical fibres are coupled to the plug-in circuit board there is a danger that the circuit a board could be withdrawn while the optical fibre is still coupled thereto, in which case it is likely that the optical fibre may be strained and damaged. The preventative arrangement comprises an aperture 26 in shelf 8 located such that when the edge connector 29 of a plug-in circuit board supported in guide rails 1~4 is mated with connector 25, optical coupler sockets 27, (Fig. 3) supported on support bracket 28, are located immediately beneath aperture 26, but clear of the edges of the aperture. When Ssockets 27 are coupled to optical coupler plugs (not shown), the plugs are :within the boundary of aperture 26. The ref or the plug-in circuit board Scannot be withdrawn because the optical coupler plug will abut the front edge of aperture 26. To withdraw the plug-in circuit board the optical plurality of discrete apertures 26, or one extended aperture whose length extends the width of shelf 8. As shown and described in relation to Fig.

Pig. 5 shows a preferred top shelf 8 having two double rows of closely spaced holes 12 and 13 between which is located an array of ventilation holes 31. An elongated rectangular aperture 26 extends virtually the whole width of shelf 8 to accommodate optical connectors which may be fitted to any of the circuit boards mounted in the guide rails. The double row of holes 12 and 13 permits a high degree of flexibility in spacing the circuit board guide means.

The spacing between plug-in circuit boards can be selected, depending on the dimensions of components mounted therein. This can be easily accomplished by locating the resilient tabs of guide rails 14 in appropriately spaced holes 11 and 12.

*o While the present invention has been described with regard to many particulars, it is to be understood that equivalents may be readily substio o\ tuted without departing from the scope of the invention.

«o 0 9 i If I t; Ct C EC CC C C C (I t -K: a

Claims

1. A sub-rack arrangement for electronic equipment, comprising a first wall member and a second wall member disposed in a fixed parallel spaced relationship and joined by two side wall members to define a space, said spa., being divided into a first compartmcnt and a second compartment by a planar shelf member extending between said side wall members and lying in a plane substantially parallel to the plane of the first wall member and the second wall member, said first compartment being defined by at least the first wall member and the shelf member, and the second compartment being defined by the second wall member and the shelf member, and a rear panel of insulating material incorporating a plurality of conductive tracks thereon, said rear panel being disposed in a plane substantially normal to the planes of said wall members and forming the rear wall of the first compart- ment and the second compartment, wherein said first wall member and said shelf member are provided with guide member means on interfacing sides thereof for slidably receiving and supporting a first pair of opposite edges of at least one demountable circuit board provided with a first mateable connector means mounted proximate an edge thereof, which edge is substantially normal to said first opposite edges, and wherein the rear panel of said first compartment has mounted thereon at least one second mateable connector means for mating with said first mateable connector means of a supported circuit board, the rear panel of said second compart- ment having mounted thereon at least an array of terminal means contacts of which are connected to contacts of said second mateable connector means via conductive tracks on said rear panel.

2. An arrangement as claimed in claim 1, wherein said rear panel is attached to an interfacing edge of said shelf member.

3. An arrangement as claimed in claim 1 or 2, wherein said shelf mem- ber is provided with a flange member about its periphery, said flange mem- Xepr extending substantially normal to said shelf members major surface. prov said wher parti plac

6. wher part

7. o whey a o whi pa C be o O whe e hol at] paii ber 0 whe 1. i hol t yen CI 1 whe for soc 1 cl ;u o^ V II II I. 2 21 rr 2') I e i 1 0 -1 Li--~ 0 *0 0 0 0 000*04 0 0 00 ~10 00 0 0 0 0~ 00 0 00* 0 0* 00 0 040 4. An arrangement as claimed in claim 3, wherein the flange member is provided on its interfacing edge with a plurality of stud members to which said rear panel is attached. An arrangement as claimed in any one of the preceding claims, wherein said terminal means mounted on said rear panel in the second com- partment comprise at least one terminal assembly having insulation dis- placement elements. 6. An arrangement as claimed in any one of the preceding claims, wherein said terminal means mounted on said rear panel in said second con-- partinent includes at least one co-axial connector element. 7. An arrangement as claimed in any one of the preceding claims, wherein a cable aperture is provided in at least one of the two side walls which define said second compartment.

8. An arrangement as claimed in any one of the preceding claims, wherein said first wall member and said shelf member are each provided with at least two rows of spaced holes forming pairs of opposite holes, each pair of holes receiving resilient mounting tabs provided on said guide mem- bers.

9. An arrangement as claimed in any one of the preceding claims, wherein said shelf member is provided with an array of first ventilation holes.

10. An arrangement as claimed in claim 9, wherein said array of first ventilation holes lies between said at least two rows of spaced holes.

11. An arrangement as claimed in any one of the preceding claims wherein said shelf member is provided with an optical fibre plug aperture for containing at least one optical fibre plug when it is coupled to a socket mounted on at least one demountable circuit board.

12. An arrangement as claimed in any one of the preceding claims, in- cluding a removable front cover panel. 00*$ 00 *0 0 0* 0 01 *0;1 ~I I I III I I. I t r t V t t

13. An arrangement 3.s claimed in claim 12, wherein said front cover panel includes pivot means on which said front cover panel is swung.

14. An arrangement as claimed in claims 12 or 13, wherein said front cover panel includes an array of second ventilator holes. An arrangement as claimed in any one of claims 12, 13 or 14, wherein two opposite side edges of the front cover panel are respectively provided with a channel means arranged to slidably co-operate with a pair of opposite narrow ledges extended from the first wall member beyond each side wall, said ledges slidably supporting the front cover panel when it is swung away from said sub-rack and slid beneath the second wall member.

16. A sub-rack arrangement substantially as herein described with ref- erence to Figs. 1 to 5 of the accompanying drawings.

17. A telecommunication equipment rack incorporating at least one sub- rack arrangement as claimed in any one of the preceding claims. DATED THIS TWENTY-FIRST DAY OF NOVEMvBER, 1989 STANDARD TELEPHONES AND CABLES PTY. LIMITED 9 I Ct I IC /2 A