WO1992015187A1

WO1992015187A1 - Stiffening element

Info

Publication number: WO1992015187A1
Application number: PCT/DE1991/000974
Authority: WO
Inventors: Hans-Werner Kranz; Eugen Assel
Original assignee: Siemens Aktiengesellschaft
Priority date: 1991-02-20
Filing date: 1991-12-13
Publication date: 1992-09-03
Also published as: DE9102008U1

Abstract

The invention concerns a stiffening element (2) for an assembled printed circuit board (4) with at least two plug-in connectors (6, 8). The stiffening element (2) consists of a shaped section (10) with a groove (28) running parallel to the narrow side (30, 32). The width (bN) of the groove is equal to the thickness (dL) of the printed circuit board and the depth (tN) corresponds to the marginal surface of the printed circuit board on which the components are not mounted. The length (1) of the shaped section (10) is equal to the distance (d) between the two plug-in connectors (6, 8). This makes it possible to restraighten bent assembled printed circuit boards (4) in the longitudinal axis of the plug-in connectors. These assembled printed circuit boards (4) can then be plugged in again without difficulty.

Description

Stiffening element

The invention relates to a stiffening element for an assembled printed circuit board with at least two plug connectors and to a stiffening element for an assembled printed circuit board with a connector.

For problem-free insertion of assemblies or assembled printed circuit boards with a plug connector or at least two plug connectors in a subrack or for fulfilling standardized plug-in conditions for free plug connectors, assemblies and / or assemblies bent around the longitudinal axis of the plug connector are particularly useful. PCB stiffening and centering elements required.

A fastening means for plug-in connectors for printed circuit boards is known from US Pat. No. 4,134,632. A bracket is provided as the fastening means, which fastens the plug connectors on the printed circuit board by gripping around the plug strips and guide pins, which are fastened to bulges of the bracket, engaging in the fastening holes of the plug connector while the bracket is connected to the printed circuit board. The bulges are supported on the fastening areas of the plug connectors. By means of this fastening means, the plug connectors are fastened to the printed circuit board in such a way that the printed circuit board can no longer splinter due to the fastening. This also stiffens the circuit board in the longitudinal axis of the connector.

A stiffening and coding device for a printed circuit board of a plug-in module, which is provided with at least two spaced plug-in connectors, is known from utility model G 88 05 197. This stiffening and coding device consists of a cuboid block with a high resistance moment, which connects the spaced plug connectors to one another in such a way that the block is supported on the printed circuit board and in each case a fastening area of the plug connectors. The length of the block corresponds to the distance of the two connectors. In order to further increase the rigidity of the printed circuit board, the block is provided with at least one bracket which engages around a plug connector and is supported on its second fastening area. A narrow side of the block facing away from the front of the plug-in module is provided with a receptacle for means for centering and coding the plug-in module.

From DE 34 13 862 AI a stiffener for a printed circuit board is known. This is a printed circuit board which is inserted as a backplane between two rear cross rails of a subrack. A web is provided as stiffening, which extends from one of the two cross rails to the other and is connected to the printed circuit board at several points. This avoids bending or deformation of the printed circuit board, for example when pulling or plugging in assemblies.

From US Pat. No. 3,491,267, circuit board busbars for the current distribution on printed circuit boards for direct plugging are known. These circuit board busbars are plugged into the circuit board at any point, the busbars running at right angles and / or parallel to one another. In addition to the function as a component for power supply and interference suppression, they also serve to increase the rigidity of the circuit board.

In these known embodiments of stiffening and centering elements, they are installed either on one side on the assembly or on both sides on the assembly and in the subrack. These known embodiments have the following disadvantages:

- restriction of the PCB assembly area due to the element fastening,

- Consideration when installing connectors,

- Retrofitting in the test field / service is not possible or only possible to a limited extent, - Use only for a certain subrack structure,

- Use for a specified connector assignment in the rack,

- Consideration of clearances and creepage distances.

The invention is based on the object of specifying a stiffening element for an assembled printed circuit board with one or at least two plug connectors, which eliminates the disadvantages listed.

The object is achieved according to the invention with the features of claim 1 or 2.

Characterized in that the stiffening element according to the invention consists of a cuboid shaped part with a groove running parallel to the narrow side, the groove width of which corresponds to the circuit board thickness and the groove depth of the free area of the edge of the printed circuit board, and the length of the molded part corresponds to the distance between the two connectors , the printed circuit board with the connectors is inserted in the

Connector longitudinal axis aligned, i.e. the deflection is reduced to a minimum in order to meet the plug-in conditions. With this configuration of the stiffening element, the element can be retrofitted, i.e. retrofitting in the test field / service is possible. Since this element is subsequently plugged onto the printed circuit board and uses only the printed circuit board edge blank area, the printed circuit board mounting area is not restricted and the stiffening element need not be taken into account when installing the connector.

In a further embodiment of the stiffening element, which is provided for a printed circuit board with a plug connector, the stiffening element consists of a cuboid shaped part, one end face of which is provided with two spaced webs and the other end face of which is provided with an adapter piece, the spacing of the webs corresponds to the width of the connector, the molding and the adapter piece is provided with a groove extending to the common narrow side. The free edge of the printed circuit board is aligned by the one-sided fork-shaped formation of the stiffening element and the long groove.

In an advantageous embodiment of the stiffening element for a printed circuit board with at least two plug connectors, the end faces of the molded part are each provided with spaced webs, the spacing of these webs in each case corresponding to the width of a plug connector.

In a further advantageous embodiment of the stiffening element for an assembled printed circuit board with at least two plug connectors, the end faces of the molded part are each provided with a frame-shaped web, each frame-shaped web being designed in such a way that each connector is used as intended is enclosed.

These two advantageous embodiments center the connectors, i.e. aligned in the longitudinal axis of the connector, whereby the assembled printed circuit board is straightened again. Since in these embodiments of the stiffening element this element is clamped to the plug connectors by the straightening oments that occur, a groove can be dispensed with here.

In a further advantageous embodiment of the stiffening element, resilient latching hooks can be provided instead of the groove, which are attached to a flat side of the cuboid-shaped part in such a way that when these latching hooks are used as intended, the connectors engage behind.

For a cost-effective production of the stiffening element, plastic is provided as the material, so that the stiffening element can be manufactured as a molded plastic part. To further explain the invention, reference is made to the drawing, in which several embodiments of the stiffening element according to the invention are schematically illustrated.

Figure 1 shows a first embodiment of the stiffening element, Figure 2 shows the rear view and in

Figure 3 shows its intended use, Figure 4 shows a second embodiment of the stiffening element and Figure 5 illustrates its intended use, Figure 6 shows the stiffening element of Figure 1 with a circuit board with a connector, Figure 7 shows a third embodiment of the Versteifungsele¬ elements, Figure 8 shows the rear view and in

FIG. 9 shows its intended use, FIG. 10 shows an advantageous embodiment of the stiffening element according to FIG. 1 and FIG. 11 illustrates a further advantageous embodiment of the stiffening element according to FIG. 1.

In Figures 1 to 11, the same parts are provided with the same reference numerals.

FIG. 1 shows a first embodiment of a stiffening element 2 for an assembled printed circuit board 4 with two plug connectors 6 and 8. The stiffening element 2 consists of a cuboid shaped part 10, both of which

End faces 12 and 14 are each provided with spaced webs 16, 18 and 20, 22. The distance d _{st of} these webs 16 and 18 or 20 and 22 correspond to the width b _ς . a plug connector 6 or 8 (FIG. 3). In addition, a flat side of the cuboid shaped part 10 facing away from the printed circuit board 4 is provided with a recess 26. Since a subrack, which receives circuit boards 4 with at least two connectors 6 and 8, has a central connecting rail, this is Stiffening element 2 is provided with a recess 26 corresponding to the connecting rail.

FIG. 2 shows the rear view of the stiffening element 2 shown in FIG. 1. The cuboid molded part 10 has a groove 28 which runs parallel to a narrow side 30 or 32 of the molded part 10. The length 1 of the molded part 10 and thus the length 1 _{N of} the groove 28 corresponds to the distance d between the two connectors 6 and 8 of the printed circuit board 4. The groove width b _{N of} this groove 28 corresponds to the circuit board thickness d. and the groove depth t _{N of} this groove 28 corresponds to a printed circuit board edge free area.

FIG. 3 shows the intended use of the stiffening element 2. The stiffening element 2 is plugged onto the printed circuit board 4 in such a way that the fork-shaped webs 16, 18 or 20, 22 connect the plug connector 6 or 8 partially embrace. When the stiffening element 2 is pushed onto the connectors 6 and 8, these are brought back into the connector longitudinal axis, i.e. the deflection of the circuit board 4 is straightened. In order to support the straightening of the deflection, particularly between the two spaced-apart plug connectors 6 and 8, the groove 28 is provided in the molded part 10, which serves to guide the printed circuit board 4. The stiffening element 2 has reached its end position when the printed circuit board 4 is inserted in the groove 28 of the molded part 10 of the stiffening element 2. Due to a moment applied by the stiffening element 2, which counteracts the bending moment of the printed circuit board 4, the stiffening element 2 is clamped to the printed circuit board 4 and the plug connectors 6 and 8.

In the embodiment shown in FIG. 1, a groove 28 can be dispensed with without having to accept disadvantages. The torque to be applied by the stiffening element 2 with a high resistance moment is sufficient to minimize the deflection of the printed circuit board 4 and thereby itself to be clamped with the printed circuit board 4 in such a way that the stiffening element 2 is captively attached to the printed circuit board 4.

By aligning this populated circuit board 4 with two connectors 6 and 8 in the longitudinal axis of the connector, bent assemblies 4 can be plugged into a rack again without any problems, or standardized plug-in conditions for free connectors can be fulfilled again without having to take measures that could possibly endanger the components on the assembly 4.

FIG. 4 shows a further embodiment of the stiffening element 2, the intended use of which is illustrated in FIG. 5. Compared to the first embodiment according to FIG. 1, the end faces 12 and 14 of the cuboid shaped part 10 are each provided with a frame-shaped web 34 and 36. These frame-shaped webs 34 and 36 are designed such that when the stiffening element 2 is used as intended, the plug connectors 6 and 8 of the printed circuit board 4 are completely framed. As a result, the moment that the stiffening element 2 counteracts the bending moment of the printed circuit board 4 has been increased.

It goes without saying that the webs 16, 18 and 20, 22 of the first embodiment according to FIG. 1 and the frame-shaped webs 34 and 36 of the second embodiment according to FIG. 4 are adapted to the individual plug connectors / design families (DIN 41612 series 1, DIN 41612 series 2) become.

FIG. 6 shows the first embodiment of the stiffening element 2 according to FIG. 1, which is provided for an assembled printed circuit board 4 with two plug connectors 6 and 8, when using a printed circuit board 4 with only one plug connector 8. The second plug connector 6 is through an adapter piece 38 is inserted, which is fastened on the printed circuit board 4 in such a way that the web ends of the bars 16 and 18 enclose this adapter piece 38 on both sides. In this embodiment of the Vers ^' teifungsele entes 2 has been dispensed with the groove 28, to recognize that the web 18 abuts the end face 40 of the circuit board 4 with its rear side. Furthermore, the front surfaces of the connector 8 and the webs 20 and 22 lie in one plane.

So that the stiffening element 2 with a high section modulus can apply a torque directed against the bending moment, the first and second embodiment of the reinforcement element 2 requires two spaced abutments, which are formed either by the plug connectors 6 and 8 or by the adapter piece 38 and the plug connector 8 .

FIG. 7 shows a third embodiment of the reinforcing element 2, the rear view of which is shown in FIG. 8 and the intended use in FIG. 9. In this embodiment, one end face of the cuboid shaped part 10 is provided with an adapter piece 42 and the other end face 14, as before, with the webs 20 and 22. The groove 28 has been extended beyond the molded part 10 by the adapter piece 42. For reasons of symmetry, the adapter piece 42 is just as long as the webs 20 and 22. This configuration of the cuboid shaped part 10 gives a stiffening element 2 for an assembled printed circuit board 4 with only one plug connector 8, the mode of operation being different from the embodiment of the stiffening element 2 according to FIG 1 or 4 has not changed.

FIG. 10 shows an advantageous refinement of the stiffening element 2 according to FIG. 1. This refinement consists in that the surface of the molded part 10 which faces the printed circuit board 4 and which receives the groove 28 is additionally provided with resilient latching hooks 44 and 46 are. These latching hooks 44 and 46 are attached to the flat side of the molded part 10 in such a way that they engage behind the connectors 6 and 8 when used as intended. These latching hooks 44 and 46 are additional means whereby a stiffening element 2 according to the embodiment according to FIG. 1 or 4 can be connected to the printed circuit board 4 in a vibration-proof manner without a groove 28. As shown in FIG. 11, codings can be provided on the flat sides 48 and 50 of the webs 16 and 20, for example a comb coding 52 which, for example, reproduces the module designation or module number in coded form.

Claims

1. stiffening element (2) for an assembled printed circuit board (4) with at least two plug connectors (6, 8), consisting of a cuboid shaped part (10) with a groove (28) running parallel to the narrow side (30, 32), the groove width ( b _N ) correspond to the circuit board thickness (d.) and the groove depth (t _N ) of the printed circuit board edge free area, and the length (1) of the molded part (10) corresponds to the distance (d) of the two plug connectors (6, 8) from one another .

2. Stiffening element (2) for an assembled printed circuit board (4) with a connector (8), consisting of a cuboid shaped part (10), one end face (14) with two spaced webs (20, 22) and the latter other end face are provided with an adapter piece (42), the distance ( _st ) of the webs (20, 22) _{corresponding} to the width (b _ςt ) of the connector (8) and one to the narrow side (30, 32) of the Molded part (10) and the adapter piece (42) extending groove (28) is provided, the groove width (b _N corresponds to the circuit board thickness (d.) And the groove depth (t _N ) corresponds to the printed circuit board edge free area.

3. stiffening element (2) according to claim 1, characterized in that the end faces (12, 14) of the molded part (10) are each provided with spaced webs (16, 18, 20, 22), the distance (d _ςt ) of the webs (16, 18, 20, 22) corresponds to the width b _st ) of the plug connector (6.8).

4. stiffening element (2) according to claim 1, characterized in that the end faces (12, 14) of the molded part (10) are each provided with a frame-shaped web (34, 36), the frame-shaped web (34, 36) being designed in this way is that one connector (6,8) is enclosed when used as intended.

5. stiffening element (2) according to one of claims 1 or 3 to 4, characterized in that the printed circuit board (4) facing flat side of the molded part (10) with resilient latching hooks (44,46) are provided such that these latching hooks when plugged on (44, 46) engage behind the plug connectors (6, 8).

6. stiffening element (2) according to one of claims 1 to 5, d a d u r c h g e k e n z e i c h n e t that a narrow side (48.50) of the webs (16.20) are provided with a coding.

7. stiffening element (2) according to one of claims 1 to 6, d a d u r c h g e k e n n z e i c h n e t that plastic is provided as the material.

8. stiffening element (2) according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that metal is provided as material.

9. stiffening element (2) according to claim 7, d a d u r c h g e k e n n z e i c h n e t that the element (2) is a plastic injection molded part.

10. stiffening element (2) according to claim 6, d a d u r c h g e k e n n z e i c h n e t that a Kammko¬ coding (52) is provided as coding.

11. stiffening element (2) according to claim 6, d a d u r c h g e k e n n z e i c h n e t that as a coding a pin coding is provided.