Printing Circuit Mounting Structure

Abstract

A mounting structure for a printed circuit board and an associated electrical edge connector. A pair of mutually opposed guides receives the circuit board and a pair of seats on said guides receives the associated electrical edge connector. Each end of the electrical edge connector is secured in the seat by a locking means consisting of an elastic projection of the guide having a shoulder for engaging the electrical edge connector. Each circuit board is of compressible plastic material having a width in excess of the nominal dimension so that when a plurality of guides are assembled side-by-side into a pack, the pack can be sidewardly compressed, resulting in the guides assuming the nominal dimension.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a mounting structure for printed circuit boards, including a pair of guides of synthetic plastic material which are disposed parallel and facing each other, and spaced so as to permit the insertion and sliding of the opposite edges of a printed circuit board between the guides, each of said guides being provided at one end with a seat adapted to receive one end of an electrical edge connector for the board.

The known structures of this type do not allow the connector to be withdrawn once it has been fixed at the ends in the respective seats in the two guides and therefore render repair and replacement operations difficult and laborious.

SUMMARY OF THE INVENTION

This difficulty is overcome by the present invention, which provides a mounting structure for printed circuit boards, including a pair of guides of synthetic plastic material which are disposed parallel and facing each other, and spaced so as to permit the insertion and sliding of the opposite edges of a printed circuit board there between. Each of the guides is provided at one end with a seat adapted to receive and lock in position one end of an electrical edge connector, this seat being formed in a projection of the guide adapted to be bent elastically with respect to the guide itself so as to permit the introduction and withdrawal of the connector.

The guide set forth in the invention is particularly seated for use with automatic wiring techniques. In known systems for mounting connectors, if it is desired to employ the technique of automatic connection of the backwiring between edge connectors by means of a wiring machine, considerable precision in the mounting of the connectors is required and the corresponding dimensions must be checked to facilitate operation with the machine, which positions itself point by point in steps of predetermined length. If the width of the guides varies, or if the connectors are not properly positioned, the machine cannot operate. In the present invention, the guides are made of compressible plastic material having a transverse width in excess of the nominal dimension, so that by assembling a plurality of guides into a pack, and compressing the pack, each of the guides and its associated edge connector will assume the desired nominal dimension. This being the case, the printed circuit boards and edge connectors are accurately positioned with respect to one another and the automatic wiring machine can be used to connect the edge connectors without further checking of dimensional accuracy.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the printed circuit board guide in accordance with this invention;

FIG. 2 is a side elevational view of a pair of the guides of FIG. 1 in opposed relationship and engaging an edge connector; and

FIG. 3 is a perspective view of a plurality of opposed pairs of the guides of FIG. 1 in combination with a mounting frame, a printed circuit board and a plurality of edge connectors.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1 the guide 1 for a printed circuit board is manufactured by molding a synthetic plastic material having a certain degree of bending and compression elasticity (for example Nylon Sniamid ASN 23/33). The central portion 2 of the guide has a reduced thickness and along a rib thereof there is formed a groove 3 adapted to permit insertion and sliding of the edge of a printed circuit board. The groove is provided with a flared entrance 4 at the front end for facilitating the insertion of the printed circuit board.

The guide 1 terminates at the ends in blocks 5 and 6, having transverse openings 7 and 8 respectively for mounting the guide 1 on parallel cylindrical rods 18, as shown in FIG. 3. Blocks 5 and 6 are constructed with plane and parallel opposite faces a and b (for example, a tolerance of 5/100 is required in the planarity of the two faces) so as to facilitate the assembly of a plurality of guides, as will be described hereinafter. The width of each of the blocks 5 and 6, that is the distance between the faces a and b, is obtained by molding with an excess tolerance, for example 13 mm. plus 0.1 mm. minus zero mm.

The block 6 at one end of the guide 1 has a projection 9 shaped so as to form a seat 10. This seat is adapted to receive and lock one end 15 of an electrical connector 14 (FIG. 2). The projection 9 is a thin elastic projection of the block 6 and which can be bent with respect to block 6. The projection 9 terminates in a lug 13 shaped like a key and including shoulder portion 16 which, by cooperating with a flange 12 of block 6, defines the seat 10 into which the end 15 of the connector 14 is fitted. The ends 15 of the edge connector 14 are provided with openings 17, while the flange 12 of each guide 1 is provided with a locating peg 11 which engages the corresponding opening 17 to position connector accurately.

For extending each connector 14 there is needed a pair of guides 1 (FIG. 2) disposed in the same plane and parallel to and facing each other and spaced so as to permit the insertion and sliding of the opposite edges of a printed circuit board along the grooves 3. Each guide 1 is mounted in a fixed position by means of a pair of the cylindrical bars 18 (FIG. 3)extending through the openings 7 and 8. Once a pair of guides 1 has been mounted in the manner described, it is possible to insert a connector 14 and then lock it in a set position for coupling to the printed circuit board inserted between the pair of guides 1. By pressing on the keys 13 of each of the two guides 1, the projections 9 can be bent away from each other to permit the insertion of the connector 14, which engages locating pegs 11 as it is inserted. The projections 9 are thereafter released and return elastically to the normal position, enclosing and locking the ends 15 of the connector in the seats 10. The withdrawal of the connector can be achieved in a manner which is similar and obvious when repair or replacement operations make this necessary.

The keys 13 of the guides also bear clearly visible indicia which identify the particular connector 14 associated with each pair of guides 1.

Referring to FIG. 3, it can be seen that it is possible to assemble a plurality of pairs of guides 1 so as to form a pack for mounting a corresponding plurality of printed circuit boards. In order to achieve this, adjacent guides 1 are mounted in a direction transverse of the boards in such manner as to cause the faces a and b of each guide 1 to mate with the faces b and a respectively, of adjacent guides. It is then possible to fix the guides 1 in predetermined nominal positions by compressing the pack of guides transversely by any suitable clamping mechanism (not shown). Granting uniformity of compression of the intermediate guides, each of the guides 1 will assume the desired nominal dimension in width. It follows that, due to the effect of the setting achieved by means of the locating pegs 11, the mounting of the connectors 14 will also take place with an approximation to the nominal dimension which is sufficient to permit operations of automatic wiring of the connectors by means of machines which are programmed to position themselves point by point at the nominal dimensions laid down for the connectors themselves.

Claims

We claim:

1. A mounting structure for mounting an electrical edge connector and a circuit board comprising at least a pair of spaced, substantially parallel, mutually opposed support members, each of said support members including a pair of guides for receiving said circuit board and at least one of said support members including means for releasably holding said edge connector, said means for releasably holding comprising an integral piece of elastic material having an opening into which an end of said edge connector fits and further having means responsive to pressure for enlarging said opening from a normal dimension in which said elastic material is relatively relaxed to an enlarged dimension in which said elastic material is relatively flexed, said means responsive to pressure being adjacent said opening and having a surface upon which finger pressure can be applied, said opening having two opposed surfaces between which said end of said connector can be inserted when said opening is enlarged, at least one of said opposed surfaces having a projection which fits into a corresponding recess in said connector, said end of said connector being insertable and removable from said opening when pressure is applied to said means responsive to pressure, which pressure makes said opening wider than said end of said connector and the said end of said connector being held by said means for releasably holding when the pressure is removed, the removal of pressure allowing said elastic material to return to said relatively relaxed state, said opposed surfaces closing on said end of said connector with said projection carried by one of said surfaces entering said recess in said end of said connector.

2. The structure according to claim 1 wherein at least one of each of said pairs of support members includes identifying indicia.

3. A mounting structure including a plurality pairs of support members in accordance with claim 2 assembled in side-by-side relationship to form a pack, each of said support members being of compressible material and having a width in excess of nominal dimension, whereby upon the application of a sideward compressing force each of said support members assumes said nominal dimension.

4. A mounting structure in accordance with claim 3 wherein each of said support members comprises a center portion and first and second end portions attached to opposite ends of said center portion and being of width greater than said center portion, said means for releaseable holding projecting from said second end portion.

5. The structure according to claim 1 wherein said guides and said means for releasably holding have in common said integral piece of elastic material.

6. A mounting structure for holding an electrical edge connector in juxtaposition to its associated printed circuit board comprising:

a pair of opposed guide members for receiving said printed circuit board therebetween,

at least one releasable holding means for holding said edge connector, said releasable holding means being formed of a single piece of elastic material fixedly attached at one end to one of said guide members with the other end projecting outwardly from said one guide member along an axis and being manually bendable from an unflexed condition aligned with said axis to a flexed condition when said other end is displaced laterally from said axis, said releasable holding means comprising:

an opening for receiving an end of said edge connector, said opening being defined by a pair of aligned opposed surfaces moveable with respect to one another between a normal closed position when said elastic material is in said unflexed condition wherein said surfaces are substantially perpendicular to said axis and engage opposite sides of said end of said edge connector to hold said edge connector therebetween and an open position of greater dimension than said end of said edge connector when said elastic material is in said flexed condition wherein at least one of said surfaces is no longer substantially perpendicular to said axis, said open position facilitating insertion and removal of said edge connector,

means responsive to manually exerted pressure attached to said other end of said releasable holding means for displacing said other end laterally of said axis so as to move said surfaces to said open position, and

a projection on one of said surfaces, said projection extending into said opening to engage a corresponding recess in said edge connector.