CA2135552A1 - Device for an electronics rack for receiving further electronic assemblies - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A device for an electronics rack having at least one electronic circuit board is adapted to receive additional electronic circuit boards, each of which can be connected in electrically conductive manner to the circuit board already present. The device has a multi-part receiving element which consists of a mounting plate with plates swingably arranged on its ends. The mounting plate has locking hooks on the sides facing towards and away from the circuit boards, by which a rear plane provided with edge connectors is detachably connected to the mounting plate and by which the device is detachably connected to the electronics rack. This provides a particularly inexpensive way of equipping an electronics rack subsequently with additional circuit boards which are connected in an electrically conductive manner to an internal system bus.

Description

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DEVICE FOR AN ELECTRONICS RACR "~`
FOR RECEIVING FI~RTHER ELE:CT}~ONIC ASSEM~3LIES

The present invention refers to a device for an electronics rack provided with at least one electronic card, capable of receiving further electronic cards, each of which can be electrically connected to the card ¦ already present.
I Electronic cards (also known as printed-circuit ,..
boards) relating to data and control electronics are generally connected to each other by connectors having a large number of pins. In known connectors a few printed-circuit boards called option cards (process-oriented modules, interface modules) are plugged into or ~ ;
equipped with such a connecting device. These option -cards must be connected electrically to the card already -~;
20 present (a standard card). Communication of the option -cards with each other or of the option cards with the ;~
standard card is effected by means of a system bus.
Connectors which have solved the problem of -,. .. .
retrofitting with option cards in various ways are 25 available on the market. ~
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~t 2 4j From the Siemens prospectus "3-SIMOREG-K Devices in ; Hybrid Technique -- Variable-Speed DC Drives" a compact !,i current-converter is known which already, in its basic ,3 concept, is provided with a number of additional and auxiliary functions. These functions are distributed over several printed-circuit boards which are arranged one above the other in the housing. Each such board is detachably connected to lugs on the housing. The communication of these boards with each other takes place via ribbon-cable bus connections. This data and j control printed-circuit board is difficult to service and unfriendly to use because it is expensive to assemble.
¦ Siemens prospectus "SIMOVERT P D.C. Link Converter 6SE12 for drives up to 37 kW", discloses a mounting or ¦ complete device of a D.C. link converter in which a swingable board holder for receiving the control board I and option boards ~process-oriented modules, interface modules) is arranged directly behind the device door of the apparatus. This board support, also known as an electronics rack, is described in detail in German Utility Model G 8 812 275. Compared to the previously mentioned converter, the option boards here are easily accessible and can be rapidly replaced as they are 2S introdu~ed into this electronics rack. The communication between the boards of this electronics rack is also effected by ribbon-cable bus connections.
The disadvantage of the electronics rack is that at the ~13 3~

time of establishing the electronics rack it must be -.
known how many boards at most are to fit into it.
In a further D.C. link converter, known from Siemens Catalog DA 66.2-1992, which is known as the "
D.C. Link Converter SIMOVERT P for Variable-Speed Three-Phase Current Drives", a board support (installation System ES 902) is provided. This board support is ;-provided in the standard version with the "Electronic ~ ~
Power Supply RPS (Rack Power Supply)" board and the ~;`
"Control and Regulating Assembly ICS (Inverter Control System)". In a standard expansion, power line feed back via an anti-parallel fully controlled power line ~
rectifier, the board support is also provided with a ; ~-"Power Line Control Set and Intermediate Control DLC ~ `
15 (D.C.-Link Controller)" board. ; -In the case of parallel-connection converters the board support is expanded by the "Pulse Distributer and Noise-Evaluation Board IPD (Inverter Pulse Distributer)" ~
board. Furthermore, this board support also has an `-20 additional four free places. The boards are ~.
electrically connected to each other via a bus conductor board, also known as a "back plane", on the rear of the -~
board support. This board support, which already has the bus connection of the option boards in the basic device, is simple but expensive to operate.

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~ 4 SUMMARY OF THE INVENTION
The present invention provides a very cost- -favorable option by which an electronics rack can be , subsequently equipped with electronic boards.
More particularly, the present invention provides a device for receiving further electronic boards, each of which can be conductively connected to a board which is already present. The device has a multi-part receiving element consisting of a mounting plate with plates for f 10 the guidance of the further boards, provided swinyably on its end. The mounting plate bearing has locking hooks on the side facing towards and away from the boards, by which, on the one hand, a back plane provided with edge connectors can be detachably connected to the ! 15 mounting plate and, on the other hand, this device can be detachably connected to the electronics rack.
In accordance with the present invention, this device provides a particularly inexpensive way of subsequently providing an electronics rack with 20 additional electronic boards. These additional boards are adapted to be electrically connected to the bus system of the board of the electronics rack which is already present. In the course of so equipping the electronics rack, which in itself may be a simple 25 housing, the housing need not be taken apart or removed. ~
Furthermore, the interchangeability of the boards is ~--retained and there is no reduction of the space for front-panel installation elements on the front side of ~' ~' ' `

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each board. Furthermore, the device of the invention can be inserted in an easy and inexpensive manner into an electronics rack without the use of tools. Upon mounting the device in an electronics rack, no additional connecting elements are required. The use of this device is possible in any housing or electronics ;~;, rack insofar as holes and receivers for the locking and fastening of the device are provided.
i The present invention has positioning pins and 1 10 positioning webs on the sides facing away from the circuit boards to facilitate its proper installation in electronics rack. ; ``
The mounting plate is conveniently provided with a recess in the shadow of the edge connectors to 15 accommodate the contact pins extending from the back of ~
the bus circuit board. The mounting plate further -includes a support arm and holding arm on the side facing the circuit boards by which a two-part back plane can be fastened and its position adjusted. Indeed, the 20 back plane may be formed of several parts. ~
Film hinges join the swingable plates to both ends ~ ;
of the mounting plate. This allows the invention to be ~ ~-~
shipped and stored in a space-efficient flat position until ready for installation in an electronics rack. At that time, the plates can be bent out of the flat position and locked into the correct position -(perpendicular to the mounting plate) with locking hooks. The base part of the locking hooks acts as ;~

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2 ~ 3 5 ~ ~ 2 spacers to keep the plates in the proper position. Each swingable plate includes detent hooks on the side facing j away from the circuit boards to properly lock the t~ invention into place in the electronics rack.

BRIEF DESCRIPTION OF THE DRAWINGS
By way of further explanation, reference is had to the drawing, which diagrammatically shows one embodiment of the device in accordance with the invention.
Fig. 1 shows a front view of a multi-part receiving element of a device in accordance with an embodiment of the present invention in the condition in which it is delivered.
Fig. 2 shows a rear view of the multi-part receiving element of Fig. 1.
Fig. 3 shows the device of the present invention in mounting condition.
Fig. 4 shows the device of the invention in an electronics rack.
Fig. 5 shows the course of the subsequent equipping of an electronics rac~ with the device in accordance with the invention.
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DETAILED DESCRIPTION
Fig. 1 is a front view, i.e., the side 6 facing the additional boards 2 and 4 (Fig. 5) of a multi-part receiving element 8 of a device 10 in accordance with ;~
the present invention which is shown in mounting :- ..... .... .......................................................... ... ..... .. ,.: ::
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7 ,-condition in Fig. 3. This multi-part receiving element ~ ~-8 consists of a mounting plate 12 and swingable plates 14 and 16. These swingable plates 14 and 16 are each connected by a film hinge 18 to an end side 20, 22 of the mounting plate 12. The film hinges 18 are so developed that the plates 14 and 16, also known as arms, can be bent out of the position in which they are supplied (as shown in Fig. 1), approximately at right angles to the mounting plate 12, also known as rear wall. In this so-called mounting condition (Fig. 3) the arms 14 and 16 rest against the ends 20 and 22 respectively of the rear wall 12. The arms 14 and 16 ;
are in each case provided with guides 24 which are intended to guide the additional electronic boards 2 and `~
lS 4 as shown in Fig. 5. These guides 24 can be provided ¦ with spring elements so that the circuit boards 2 and 4 (Fig. 5) are fixed in the guides 24. Furthermore, the I arms 14 and 16 are provided with vent holes, the ( arrangement and geometrical dimensions of these vent 20 holes depending on the vent holes of the electronics ;~
rack 26.
As shown in Fig. 1, the mounting plate 12 has, on the side 6, locking hooks 28, support arms 30, a holder arm 32, and recesses 34. By means of the locking hooks ~ ;
28, the support arms 30, and the holder arm 32, a two-part back plane 36 (Fig. 3), (also known as bus circuit ;;
board~ is fastened and adjusted. As can be noted from Fig. 3, this bus circuit board 36 consists of a circuit ~1 2 ~ 3.~ 2 o . 8 J board, in particular a multi-layer circuit board, and of :. several edge connectors 38. Thle circuit board contains ! all necessary electrical connections of the contact pins for the edge connectors 38 present. The upper part of the two-part rear plane 36 rests on the support arms 30 and is fastened by means of the locking hooks 28. The lower part of the two-part rear plane 36 is held by the holding arm 32 and a locking hook 28. The rear wall 12 of the multi-part receiving part 8 can also be provided - :
with a single-part back plane 36 which, for instance, has edge connectors 38 for more than two additional circuit boards 2 and 4. In the case of a single-part bus circuit board 36, the support arms 30 and the holder arm 32 are no longer required.
The bus circuit board 36 has the ends of the :
contact pins of the edge connectors 38 on its solder side, so that no flat surface is present on the solder side of the bus circuit board 36. In order that such a f bus circuit board 36 can be fastened to the mounting 20 plate 12, the locking hooks 28, the support arms 30 and :
the holding arm 32 are either of a length corresponding to the length by which the contact-pins lengths extend out of the bus circuit board 36, or else, as shown in .
Fig. 1, the mounting plate 12 has recesses 34 which ;.`~
receive the length of the contact pins extending out of the bus circuit board 36. The recesses 34 are arranged, in each case, in the shadow of a edge connector 38 of :~
the bus circuit board 36. In this way, the rear plane ~.
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:Y 36 can be mounted at minimal distance from the rear wall ~
12, so that the additional boards 2 and 4 and a board 40 -~; which is already present in the ~lectronics rack 26 form a plane on the front side ~Fig. 5).
!; 5 On locking hooks 28 there are provided double-3 detent hooks which are spaced from each other. The ~; space between the adjacent detent hooks increases towards the hook on the free end and the hooks are arranged on facing sides of the detent hooks. With such a locking hook 28 there is obtained a stable locking of the rear plane 36 to the rear wall-12, which can also be I easily produced. By the use of several locking hooks 28 for the fastening of the rear plane 36 to the rear wall 12 of the multi-part receiving part 8, the locking hooks 28 also take over the adjustment task.
Fig. 2 is a rear view of the multi-part receiving element 8. It can be noted from this view that the side 42 of the rear wall 12 facing away from the boards 2 and ( 4 also has locking hooks 28 and positioning pins 44. By means of these locking hooks 28 and positioning pins 44, the multi-part receiving part 8 is fixed in the housing ~-26 and locked in the rear wall of the housing 26 (Fig.

4). The rear sides of the arms 14 and 16 also each have detent hooks 46 and positioning webs 48, the arm 16 being cut away to the greatest part in Figure 2. By means of these detent hooks 46 and positioning webs 48, the arms 14 and 16 can in each case be fixed and locked in the cover ancl bottom of the electronics rack 26.

~ 2 1 3 .~ 2 ';, 10 . From Figs. l and 2 it can also be noted that the multi-part receiving element 8 is made in a single piece as a plastic injection molding. In this way, the receiving element 8 can be mass produced at low cost and 5 is of sufficient stiffness to assure dependable mounting in the electronics rack 26 and a suitable use of this device 10 for receiving further option boards 2 and 4.
As already mentioned, Fig. 3 shows the device 10 for receiving in mounting condition additional boards 2 3 10 and 4, not shown here in order to avoid cluttering the drawing. The mounting condition of the device 10 is characterized by the fact that the back plane 36 is fastened to the rear wall 12 of the multi-part receiving part 8 and that the two arms 14 and 16 which are lS swingably arranged at the ends form approximately a right angle with the rear wall 12.
This embodiment of the multi-part receiving element -`~
8 differs from the embodiment shown in Fig. 1 by the fact that the arms 14 and 16 arranged on the end sides 20 are provided here with guides 24, each arranged on a side 50 facing the boards 2 and 4. Furthermore, each of `
the guides 24 is provided with spring elements 52. -These spring elements 52 are a part of each guide 24 -which, in its turn, is part of an arm 14 or 16. These 25 spring elements 52 fix the corresponding boards 2 and 4 ;~
in the guide and compensate for tolerances in thickness of the boards 2 and 4 and/or manufacturing tolerances of the injection molded element 8.
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Fig. 4 shows an electronics rack 26 without standard board 40 and without aclditional boards 2 and 4, - ;~
in which rack the device 10 of the invention for the receiving of additional electronic boards 2 and 4 is placed and locked. For the housing 26, a shaped sheet-metal part is provided, the shape of the housing 26 being produced by bending this shaped sheet-metal part along predetermined edge lines. By means of this shaped sheet-metal part there is obtained a one-piece, rigid, economical housing 26. The housing 26 is provided on its rear wall 54 with an opening 56 produced by bending a part of the rear-wall plate inward at a right angle, as a result of which this part serves as holding plate 58 for a multi-pin edge connector 60. The bottom 62 and the cover of this electronics rack 26 are each provided with a guide 64 which is so arranged that a blade connector 66 (Fig. 5) of a standard board 40 engages in the edge connector 60 upon the pushing-in of this standard board 40.
The manner of assembling the device 10 for the - ~;
receiving of further boards 2 and 4 will be explained on basis of Figs. 4 and 5.
, An existing elec~-onics rack 26 which already contains a standard board 40 is to be subsequently equipped with two additional circuit boards 2 and 4.
The electronics rack 26 differs from the embodiment of the housing 26 in Fig. 4 by the fact that the side wall on the left has been dispensed with, whereby the housing .`, ! . ' 2 1 ~ 2 26 is further simplified. With converters, standard board 40 is a regulation and control board, which is provided with a control terminal strip 66 and an interface terminal strip 68. In the inserted position 5 of the standard board 40 shown here, the control -~
terminal strip 66 is in contact with the edge connector 60 (Fig. 4) on the holding plate 58 of the housing 26.
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The interface terminal strip 68 is not in contact with ` ~
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an edge connector in the standard version. `~
If this electronics rack 26 is now to be further ;~
equipped, then the standard board 40 must be pulled out -~
7 of this housing 26 so that the device 10 of the I invention can be introduced in mounting position into the housing 26. Upon the introduction of this device 10 into the electronics rack 26, the device 10 is guided by the side wall of the housing and/or by the two guides 64 present. When the rear wall of the housing is reached, the locking hooks 28 on the arms 14 and 16 and the opposite side 42 of the mounting plate 12 snap into corresponding openings and receivers in the housing 26, . ~: . ,.
thus fastening the device 10 for receiving additional circuit boards 2 and 4 while in the housing 26. The locking hooks 28 of the device 10 have not been shown her.e. Thereafter, the original standard board can be inserted as customary in place and fastened. The interface terminal strip 68 now engages into an edge ;
connector 38 of the bus circuit board 36. In this way, the bus system of the standard board 40 is connected by `~

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21~a~2 the interface terminal strip 68 to the bus circuit board 36 of the device 10. Additional circuit boards 2 and 4 (for example, a process-oriented module and an interface module) can now be inserted and connected in electrically conductive manner with the bus system of the standard circuit board 40.
Upon the mounting of the device 10 for the receiving of additional electronic boards 2 and 4, no ~ool is necessary. Furthermore, no additional connecting parts are required.
With this device lO in accordance with the invention there is now the possibility, on the one hand, `~
of being able to construct the electronics rack 26 in a particularly simple manner and, on the other hand, of being able to equip such a simple electronics rack 26 with additional boards 2 and 4, which can be installed economically, easily, and without tools, rapidly on the spot.

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Claims (12)

1. A device for an electronics rack that has at least one electronic circuit board for receiving further electronic circuit boards, that can be electrically connected with the board already present, the device comprising a multi-part receiving element including a mounting plate; end plates, arranged swingably on the ends of said mounting plate and including guides, for additional circuit boards; locking hooks on sides of the mounting plate facing and away from the circuit boards whereby a rear plane provided with edge connectors can be detachably connected to the mounting plate; and, wherein said element can be detachably connected to the electronics rack.

2. The device of claim 1, in which the base part of the locking hook acts as spacer.

3. The device of claim 1, in which the mounting plate includes positioning pins on a side facing away from the circuit boards.

4. The device of claim 1, in which the end plates have positioning webs on the sides facing away from the circuit boards.

5. The device of claim 1, in which the mounting plate is provided with at least one recess in a shadow of the edge connectors of the rear plane.

6. The device of claim 1, in which a film hinge is provided as swingable connection between said mounting plate and said end plates.

7. The device of claim 1, in which the mounting plate includes a support arm for the rear plate on the side facing the circuit boards.

8. The device of claim 1, in which the mounting plate includes holding arm on the side facing the circuit boards.

9. The device of claim 1, in which each of the end plates is provided with detent hooks on a side facing away from the circuit boards.

10. The device of claim 1, in which the rear plane is formed in several parts.

11. The device of claim 1, in which the multi-part receiving element is formed as one piece.

12. The device of any of claims 1 and 11, in which said multi-part receiving part element comprises a plastic injection molded portion.