AU600989B2

AU600989B2 - Circuit board extractor arrangement

Info

Publication number: AU600989B2
Application number: AU80882/87A
Authority: AU
Inventors: Herbert Nemeth
Original assignee: Alcatel NV
Current assignee: Alcatel Lucent NV
Priority date: 1986-11-20
Filing date: 1987-11-09
Publication date: 1990-08-30
Anticipated expiration: 2007-11-09
Also published as: EP0269608A2; AT390706B; EP0269608A3; ATA310586A; AU8088287A

Description

ORIGINAL

COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-1969 This document contains the amendments made uinder Section 49 and is correct for printing COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED "CIRCUIT BOARD EXTRACTOR ARRAN~GEMENT'? The following statement is a full description of this invention, including the best method of performing it known to us:- To: The Commissioner of Patents.

I- i 4b This invention relates to an arrangement for inserting and extracting a plug-in circuit board slidably supported on its side edges by a pair of spaced guide rail means attached to a sub-rack, the circuit board inlcuding a multi-contact connector element mounted on its rear edge which couples with a ounter element on the sub-rack.

Various arrangements of the aforementioned type are known, and they are mainly used to apply the force which is necessary to open the contact springs of the connector elements and to overcome the frictional forces between those contacts without damaging the printed circuit board. This is

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E0 particularly important with regard to the ever-increasing tendency towards te miniaturization and, as a result of this development, the steadily increasft ing number of contacts per printed circuit board. The force necessary to Sinsert and withdraw the printed circuit board has become such as to cause the printed circuit board and the connectorcontact springs to be deformed or damaged if the operation is not executed precisely.

These known arrangements are complicated and of such design as to prevent full utilization of space in the vicinity of the circuit boards for cable ducts.

It is an object of the present invention to provide an arrangement which attains by simple means'and without using space around the front of the printed circuit board, the efficient insertion and extraction of the board.

According to the present invention there is provided an arrangement for inserting and extracting a plug-in circuit board slidably supported on its side edges by a pair of spaced guide rail means attached to a sub-rack means by means which include at least one transverse member, said sub-rack means having at least one counter connector element for coupling with at least one multi-contact connector element mounted on said circuit board's rear edge, wherein said circuit board includes a pair of hinged lever means each comprising a handle part connected to a lever part, each lever means )ji i i- i i being pivotally supported by a bearing means attached at respective front corner parts of said circuit board defined by a side edge and the said boards front edge, the free end of each said lever part co-operating with a respective groove in said transverse member upon initial registration of contacts of the connector elements such that by actuation of each said handle means in one direction the resulting leverage urges said circuit board towards said counter connector element to a coupled position in which the connector elements are fully coupled and said circuit board locked in said coupled position, and actuating each said handle means in the opposite dil Q~ rection the resulting leverage urges said circuit board away from said counter connector element to a de-coupled position in which the connector elements are de-coupled and the said circuit board unlocked.

The present invention attains an improved arrangement by hinging the operating levers at a grip ledge which is connected with the outer front edge. In the withdrawn state of the printed circuit board these operating levers are mainly situated within the boundary of the side edges of the printed circuit board. Thus, this grip ledge carries the operating levers including their hinging areas, which on the one hand makes it unnecessary to take additional measures on the printed circuit board itself for the hinging of the operating levers and on the other hand simple production, installation and maintenance are secured. Because in the movable state of the printed circuit board, when the contacts between the connector elements are not yet coupled, and the operating levers are situated within the boundary of the side edges of the printed circuit board, the area outside of the side edges of the printed circuit board is still available for the installation of cable ducts, etc., which makes possible a compact design.

In a further embodiment of the present invention a handle in the middle section of the grip ledge is provided, at which the handles of the operating levers are hinged in the inserted state. This middle handle enables safe handling of the printed circuit board independent of the movable operating levers, whereby in the state of completed insertion of the printed circuit board or even if the printed circuit board is stored outside the equipment, the grip ledge appears to be closed excluding erroneous operation.

According to a further preferred embodiment of the present invention, the operating levers may be kept in the coupled and de-coupled position by resilient end locks, the interacting parts of these end locks being mounted on the operating lever and on the grip ledge. In the de-coupled position held by the operating levers for inserting and withdrawing the printed cir- 10 cult board, the operating levers are resiliently fixed in their rotating Stt position opposite the printed circuit board, thus enabling the printed cir- C~r Iti tee cuit board to be moved solely by means of the middle handle. It is therefore not necessary for the operator to pay attention to the operating levers or to hold them. When inserting directly, that is when the contacts between the connector elements are closed, the operating levers are moved Sinto their coupled position, where they are, again, protected by the end locks opposite the printed circuit board, thus securing transport prot Stection and protection against vibration when being operated.

According to a still further embodiment of the invention, in the inserted state the grip ledge can cover almost completely the vertical space available for the printed circuit board, thus providing protection against electric shock from the electric units and components on the printed circuit board. A closed cooling air duct inside the housing accomodating the printed circuit board is possible.

In a still further embodiment of the present invention the grip ledge is provided with windows and apertures through which front elements such as plugs, switches and displays can be operated and viewed. No additional space is required at the front-end of the printed circuit board for front cabling etc. The windows or apertures may be provided in small plates which alternatively designed according to the respective requirements 1 are insertable into larger apertures of the grip ledge. Identification of the printed circuit board such as identification labels with short identification codes, bar codes etc. can be provided on the grip ledge, as well as other instructions or warnings of electrostatic sensitive components.

Thus the arrangement becomes clearly arranged and easy to check.

The grip ledge and the operating levers may comprise material with defined conductivity, such as a conductive synthetic material, whereby due to the contact between the operating levers and the appropriate grooves in the inserted state of the printed circuit board these operating levers create an electric contact with the transverse supports. With this embodiment of the present invention, potential differences occurring between the printed circuit board or other plug-in units and, the operator, are discharged via the grip l.edge, the operating lever and the transverse support without influencing the functioning of the components installed on the V printed circuit board or the plug-in units.

If according to a still further preferred feature of the present in- Svention, the grip ledge including the operating levers are connected elec- Strically with the ground of the printed circuit board via a defined leakage resistance, slow potential equalization against the ground potential of the printed circuit boards and at the same time an effective protection of the components against electrostatic charging during the manipulation are possible.

According to a still further advantageous embodiment of the present invention, for the purpose of electric and magnetic shielding the grip ledge may have a metal coating which, for example, may consist of Ni. This coating can be easily applied during the production process of the grip ledge and makes additional shielding precautions in the area of the PCB's front-end unnecessary.

In the following, the invention is described in detail by the example of an embodiment depicted in the drawings.

Fig. 1 shows a partly schematical section of an arrangement accoridng to the invention for inserting and withdrawing a printed circuit board with electric components; Fig. 2 shows an enlargement of detail II of Fig. i, in which the cable duct is removed and the printed circuiit board is in the withdrawn state; Fig. 3 shows the same detail as Fig. 2 in which the printed circuit board is inserted completely; and Figs. 4 and 5 each show enlargements of the details IV and V of Fig. 2 Sor 3, respectively.

lc For the purpose of explaining the invention, only the transverse supports 1, 2, 2' as well as the longitudinal supports 3 being supported by the aforementioned transverse supports which are fixed to the sub-rack are necessary. The sub-rack however, is not depicted in the drawings. In the longitudinal supports 3 a printed circuit board 4 with electric components (not shown) is guided in the direction of arrow 5. This printed circuit board carries a male or female multi-point connector 7 with a large number of contact pins or contact springs at its inner front-end 6. Multipoint connector 7 in the fully inserted state of the printed circuit board 4 this state being indicated by a continuous line interacts with a male or female counter multipoint connector, thus providing the electric connections to the printed circuit board which are necessary for the operation of the whole arrangement; the counter multipoint connector is not shown.

Because of the large number of contacts of the multipoint connector 7, which has become necessary due to today's larger density of the components mounted on each printed circuit board, considerable force is required to overcome the contact forces and frictional forces when the multipoint connector 7 is inserted into the counter multipoint connector; this also applies to the withdrawal of the printed circuit board. In order to be able to apply this force safely and without any possibility of damage to the multipoint connectors and/or their contacts, two operating levers 11 which 6 7

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'-4 -4 are rotatable at the FOB level and hinged onto the printed circuit board 4 (see arrow 10) are arranged in the area of the outer corners 8, 9 of printed circuit board These operating levers 12. interact with a locking arm 12 hooking into grooves 13 fixed to the equipment. This hooking-inoperation takes place as the contacts of the connection elements are interacting.

Fig. 1 also shows a grip ledge 15 connected with the outer front edge 1~4 of the printed circuit board 4. This grip ledge 15 has a middle handle 16 at which the operating levers 11 are hinged (see Figs. 2 and 3).

In the inserted state of printed circuit board L4, locking arms 12 are Shooked into grooves 13 which are notched at the transverse supports 1 or 2, 44 respectively. The coupled position of the operating levers 11 is fixed by Send locks (see Figs. 2 and thus transport protection as well as protection against vibration is attained. To withdraw printed circuit board 4I Sinto the position indicated in Fig. 1 with dash-dotted lines, the operating levers 11 are swung from the coupled position into the movement end position where they are located within the boundary of the side edges 17 of the Aprinted circuit board, and held by means of the end locks. Thus, space in the area of the front lower transverse support 2 is created which can be used for the cable duct 18. Thereby providing very compact architecture.

In the detail depicted in Fig. 2 printed circuit board 4I is in the withdrawn state in which the connector elements (not shown) are un-coupled.

The side edges 17 of the printed circuit board can freely slide in respective grooves of the longitudinal supports 3. This movement, is indicated by arrow 5. In Fig. 2 the cross section of the transverse support 2 can be seen as well, which has a longitudinal groove 19 for the installation of the cable duct (not shown. Fig. 2 also shows a further longitudinal groove for installation, adjustment and support of the longitudinal supports 3 as well as a groove 21, which together with a stopping surface 22 forms the groove 13 for the locking arm 12 of the operating lever 11.

When printed circuit board 4 is shifted from the withdrawn position shown in Fig. 2 to the inserted positon by means of middle handle 16 of grip ledge 15. The connector element at the inner front-end of the printed circuit board 4 starts interacting with the counter multipoint connector element which is fixed to the equipment. In this position the locking arm 12 of operating lever 11 will already be situated above the groove 13 which on the one side is bounded by the surface 23 of groove 21, on the other side by the stopping surface 22. As soon as the operator becomes aware that the connector elements are touching, handles 24 of the operating levers 11 are pushed in the direction of middle handle 16 and the printed circuit board 4 is urged further along the longitudinal supports 3 by the t levers to reach the coupled position depicted in Fig. 3.

Starting from a state of complete insertion of printed circuit board 4 as depicted in Fig. 3, for the withdrawal thereof the operating levers 11 H only have to be swung in the outward direction. As a result the front-end of the locking arm 12 interacts with the stopping surface 22 at the longitudinal supports 3 and, printed circuit board 4 is drawn out of the contacts or contact springs of the connector elements. Thereapon further withdrawal of the printed circuit board 4 can be effected by the middle handle 16 and the operating 1 evers 11 are repositioned as shown in Fig. 2.

Referring to Figs. 4 and 5, the operating levers 11 have flexiblydesigned end locks 25 comprising a spring arm 26 in the area of the bearing ring 27, and a locking angle 28 fixed closely to the grip ledge. The bent design of the locking angle 28 provides two possible end positions for the rotation movement of the operating lever 11 relative to its hinging area fixed to the grip ledge 15, namely the de-coupled position and the coupled position. Thus when the printed circuit board is moved with the middle handle 16 towards the rear, the locking arm 12 as well as the whole operating lever 11 are kept in the de-coupled position, while the coupled position (see Figs. 5 or 3) offers a certain transport protection or protection against vibration, for the printed circuit board 4.

Referring to Figs. 1, 2 and 3 it can be seen that the vertical edge of the printed circuit board can be covered completely by the grip ledge Closing olf the inner part of the equipment. Unauthorized access and the escape of cooling air which is circulated within the equipment can be prevented. Front elements like plugs, switches and display elements or similar components (not shown) can be arranged on the printed circuit board.

I Access to these componen's can be gained through a window provided on the grip ledge 15. In Fig. 2 and 3, at the middle handle 16, a holder 29 for I identification labels is shown.

,The grip ledge 15 as well as the operating levers 11 including their hinging area comprise material of defined conductivity, such as, for example, conductive synthetic material. So that when the printed circuit board is inserted and the grooves 13 are hooked into the operating levers 11, an electric contact with the transverse supports 1 and 2 is provided. The grip ledge 15 may be connected with the ground of the printed circuit board 4 via the predetermined leak resistance which allows slow potential equalization towards ground potential possible in order to avoid negative effects of electrostatic charges on units or components. Moreover, the grip ledge 15, in order to offer electric or magnetic shielding, can have a S metal coating, e.g. a Ni-coating (not shown).

Claims

1. An arrangement for inserting and extracting a plug-in circuit board slidably supported on its side edges by a pair of spaced guide rail means attached to a sub-rack means by means which include at least one transverse member, said sub-rack means having at least one counter connector element for coupling with at least one multi-contact connector element mounted on said circuit board's rear edge, wherein said circuit board includes a grip ledge comprising an elongated member attached to the front edge of the cir- cuit board, a pair of hinged lever means each comprising a handle part con- nected to a lever part, each lever means being pivotally supported by the grip ledge and attached in proximity to respective front corner parts of said circuit board defined by a side edge and the said boards front edge, the free end of each said lever part co-operating with a respective groove in said transverse member upon initial registration of contacts of the con- nector elements such that by actuation of each said handle means in one di- rection the resulting leverage urges said circuit board towards said counter connector element to a coupled position in which the connector ele- ments are fully coupled and said circuit board locked in said coupled posi- tion, and actuating each said handle means in the opposite direction the resulting leverage urges said circuit board away from said counter connec- LI I tor element to a de-coupled position in which the connector elements are Sde-coupled and the said circuit board unlocked.

2. An arrangement as claimed in claim 1, wherein each said lever part lies within the boundary of the adjacent side edge when the said circuit board is in the de-coupled position.

3. An arrangement as claimed in claim 1 or 2, wherein the lever means are resiliently retained in the coupled position and the de-coupled posi- tion by spring means.

4. An arrangement as claimed in any one of claims 1 to 3, wherein said LS grip ledge includes a cover plate. L i i 101

5. An arrang cludes apertures board. ~ement as claimed in claim wherein said cover plate in- for gaining access to elements mounted on said circuit

6. An arrangement as claimed in any one of the preceding claims, wherein said lever means and said grip ledge are formed from electrically conductive material.

7. An arrang-ment as claimed in claim 6, wherein the said printed cir- cuit board 's ground potential is connected to the lever means and the grip ledge via a predetermined resistance means.

8. An arrangement as claimed in any one of claims 1 to 7, wherein said grip ledge is provided with a metal coating.

9. An arrangement as claimed in claim 8, wherein the metal coating is an Ni coating.

An arrangement for inserting and extracting a plug-in circuit board, substantially as herein described with reference to F3igs. 1 to 5 of the accompanying drawings.

11. A communications sub-rack incorporating an arrangement as claimed in any one of the preceding claims. DATED THIS 'WENTY-EIGHTH DAY OF MAY, 1990 ALCATEL N.V.