Modular Connector for Switching Frame

My present invention relates to a switching frame, designed for selectively interlinking incoming and outgoing transmission lines of a telecommunicating system, and more particularly to a modular connector constituting one of several identical units to be assembled in such a frame.

Switching frames of the type here envisaged may be used to establish semipermanent connections between a number of incoming lines and a like number of outgoing lines of a central office; the term "lines", as here used, includes both local circuits and signal paths leading to remote stations. In some instances, as with a private branch exchange (PBX) or switchboard, the number of outgoing lines may differ from the number of incoming lines.

In all these cases it is necessary for an operator to have ready access to line terminations, such as jacks or plugs, between which a connection is to be made or broken; such access is also desirable for the purpose of connecting testing equipment to an incoming or outgoing line.

Conventional modular units of this description, which must be bolted to one another and to a supporting frame member, are inconvenient to readjust since their accessibility is limited and the process of disassembling and reassembling is time-consuming.

The object of my invention is to provide an improved modular unit for the purpose set forth which avoids these inconveniences.

In accordance with the present invention, I provide a generally prismatic connector housing preferably of generally rectangular outline, this housing having two major surfaces interconnected by at least three minor surfaces. A bank of input terminals on a first minor surface and a bank of output terminals on a preferably opposite second minor surface are respectively tied to incoming and outgoing lines which are to be selectively interlinked. A first and a second set of leads extend within the housing from the input and output terminals, respectively, and emerge in a first and a second zone at one of these major surfaces. A third and a fourth set of leads extend within the housing from third and fourth zones of the same major surface to a third minor housing surface where the terminations of these leads can be selectively interconnected by suitable linking elements or jumpers. The first and third sets of leads as well as the second and fourth sets of leads are connected to one another by conductor means preferably incorporated in a printed-circuit board forming part of the major housing surface from which these leads emerge.

Though the zones referred to need not be physically separated and may even be interlaced, it will be advantageous to provide separate compartments for the first and second sets of leads respectively assigned to the input terminals and the output terminals. In order to realize a particularly compact structure, I prefer to accommodate the two banks of terminals in respective recesses formed along the larger sides of a generally rectangular housing perimeter. This allows the associated incoming and outgoing lines to be led in by way of substantially longitudinally extending passages from the smaller side opposite the aforementioned third minor surface carrying the terminations of the third and fourth sets of leads.

According to a further feature of my invention, this third minor surface adjoins a junction box into which the lead terminations extend and which is preferably removably attached to the connector housing.

The above and other features of my invention will now be described in detail with reference to the accompanying drawing in which:

FIG. 1 is a side-elevational view of a modular connector according to my invention;

FIG. 2 is an end view of the connector shown in FIG. 1;

FIG. 3 is a view similar to FIG. 1 but with removal of a protective cover to expose an underlying printed-circuit board;

FIG. 4 is a cross-sectional view taken from above on the line IV--IV of FIG. 1;

FIG. 5 is a top view of the unit shown in FIG. 1;

FIG. 6 is an end view taken from the side opposite that of FIG. 2; and

FIG. 7 is a side-elevational view of a junction box forming a part of a unit, the box being reversed with reference to its position in FIGS. 1 and 3.

The modular connector unit shown in the drawing comprises a generally prismatic housing 1 (preferably of resinous material) forming an upper and a lower compartment 16, 17 (FIG. 3) supported by a common wall 28 (FIG. 4). The major housing surface opposite wall 28 is the outer face of a printed-circuit board 19 overlain by a cover 13 which is removably clipped thereto.

Along the larger sides of its rectangular outline, housing 1 is formed with a pair of recesses 2', 2" accommodating respective banks of terminals 3 and 4 in the shape of slanting pins. The recesses 2' and 2" are normally closed by removable lids 9', 9" clipped onto the housing by being resiliently fitted into undercuts 29', 29" and slots 20', 20". On the side opposite wall 28, however, the recesses are open even with covers 9', 9" and 13 in place.

On one of the minor housing surfaces, i.e. at left as seen in FIG. 1 and FIGS. 3-5, I provide means for removably clipping the connector unit to a supporting bar 5 carried on a switching frame partly indicated at 14. The upper edge of bar 5 fits into a groove defined by an overhanging lip 6 while its lower edge is engaged by a spring clip 7 secured to a ledge of the housing. It will be apparent that a number of identical modular units can be clipped alongside one another onto the same bar 5.

On the opposite minor surface, I provide a junction box 8 having lugs 23', 23" which slidably fit into pockets 22', 22" of housing 1. Bosses 24', 24" of box 8 have threaded bores 25', 25" to receive nonillustrated screws by which they are attached to housing wall 28, this wall being provided for that purpose with holes (not shown) aligned with bores 25', 25". Bosses 24' and 24" are integral with a block 18, bracketed by lugs 23', 23", which is frictionally or otherwise retained in the box 8 and can be extracted therefrom to enable the replacement of that box by a different one. Hinged to housing 1 at 11 is a door 10 which has a tongue 12 resiliently snapping into a groove at the top of the box when the door is closed; when it is swung open as shown in FIG. 6, access is had to two rows of contact elements 21a, 21f respectively connected to terminals 3 and 4 in a manner about to be described.

Passages 15' and 15" on the attachment side of housing 1, as best seen in FIG. 2, communicate with recesses 2' and 2" to facilitate the insertion of bundles of incoming lines a and outgoing lines f (only two of each shown) into these recesses where their extremities are tied to associated terminals 3 and 4, respectively. Each terminal 3 is connected to a lead b which extends downwardly into compartment 16 of housing 1 and then laterally outwardly, perpendicularly to the major housing surfaces, into the printed-circuit board 19 as seen in FIG. 3. In an analogous manner, terminals 4 are connected to respective leads e which pass upwardly into housing compartment 17 and then extend transversely into printed-circuit board 19. In the present instance, in which there are 24 input terminals 3 and as many output terminals 4, the ends of leads b and e are arrayed in an upper zone B and a lower zone E, respectively, of board 19. Conductor strips g and h of the printed circuit extend from these zones to two further zones C and D shown at right in FIG. 3, zone C carrying projecting ends of leads c tied to contact elements (e.g. plugs or jacks) 21a while zone D carries projecting ends of leads d tied to contact elements 21f. Leads c and d, accordingly, angularly pass into box 8 through insert 18, as best seen in FIG. 4. Thus, an electrically continuous path extends from each incoming line a via a terminal 3, a lead b, a strip g and a lead c to a respective contact element 21a on insert 18; similarly, an electrically continuous path extends from any contact element 21f on that insert by way of a lead d, a strip h, a lead e and a terminal 4 to a respective outgoing line f.

As diagrammatically indicated in FIG. 6, any input-side contact element 21a can be connected to any output-side contact element 21f by a jumper 26. FIG. 6 also shows the possibility of establishing a circuit to any line via the corresponding contact element in series with a testing device diagrammatically represented as a lamp 27.

Door 10 can carry a nonillustrated label containing information about the electrical connections to be established within junction box 8.

Obviously, the internal connections within junction box 8 between leads c, d and contact elements 21a, 21f can be modified, with different groupings of these elements and possible omission of some of them.