Hinged removable connector module

This invention relates generally to shelves for housing printed circuit packs (PCPs) and more particularly to the provision of connections for operation, administration, maintenance and provisioning functions.

Shelves for housing PCPs face significant space restrictions. This is particularly so for shelves located in a central office of a telephone switching service provider. The space available is dictated by the height, width and depth of the racks which a service provider uses for holding the shelves. It is important to minimize the space occupied by any component of a system.

A shelf typically has a printed circuit board (PCB) extending across the rear, referred to as a backplane, which has a series of connectors on its front face. Alternatively, the backplane may be placed more forwardly in the shelf and have a series of connectors on both its front and rear face. In such cases, the backplane may be referred to as a midplane. PCPs are oriented perpendicular to the backplane and plugged into the connectors on the backplane. These connectors generally have a super set of pins to match a large number of connection configurations so that a variety of different PCPs may alternatively be plugged into the same position in the backplane.

I/O connections for,carrying input and output signals to the PCPs within the shelf and connections for the control of the shelf, namely the operation, administration, maintenance and provisioning (OAM&P) of the shelf itself, are also usually made through the backplane. The type of cable connectors required for the I/O of the PCPs will vary depending on the PCPs connected to the shelf. In contrast, the number and type of connectors required for the OAM&P of a shelf supplied by a particular service provider is normally fixed.

For both I/O and OAM&P, typically a fixed pattern of cable connectors is mounted on the back surface of the backplane. Although a fixed pattern is acceptable from the OAM&P perspective, there are several disadvantages to this mode of enabling cable connections for the OAM&P of the shelf. First, access to the cable connectors is only available from the rear of the backplane. Second, the mounting of the cable connectors on the rear of the backplane means that the backplane must sit sufficiently forward in the rack to accommodate their presence. This limits the usable depth of rack and, by extension, the width of the PCPs which may be plugged into the backplane. Third, placing the cable connectors on the rear of the backplane prevents the backplane from being used in the midplane configuration. Forth, if there were a fault found with one of the OAM&P connectors, the entire backplane would need to be replaced.

One solution which has been proposed by Murphy et al. is described in U.S. Pat. No. 5,769,644. In that solution, both the I/O connections for the PCPs in the shelf and the connections for the OAM&P are done through a module which extends outward from the side of the shelf. This module can be exchanged with other connector modules where a change in the PCPs in the shelf necessitates a change in the I/O connectors. This removes the cable connectors from the rear of the backplane and allows more flexibility to change PCPs without needing to change the backplane. However, because the OAM&P connectors are on the same module, the change in the I/O connectors also results in an unnecessary change in the OAM&P connectors. Also, the module is in a fixed position relative to the shelf.

The present invention is directed to an improved shelf for housing PCPs. A backplane extends across the shelf. A connector module having the OAM&P connectors is electrically connected to the backplane and has two positions. In one position it extends sideways from the shelf with the connectors facing either forward or backward, depending on the user's preference. This allows the user front or rear access for connection to the connectors of the module. In the second position, the OAM&P connector module is substantially flush with the side of the shelf. This position allows the OAM&P module to be tucked out of the way to minimize the space used by the OAM&P module and allow access to what is behind it along the side of the shelf.

Advantageously, the OAM&P functionality is on a separate module which may be changed or left unchanged irrespective of any changes made to other connectors in the system.

Also advantageously, if used in conjunction with a system that removes the I/O connectors from the backplane, the backplane may sit more rearwardly in the shelf, and thus the size, and consequently the functionality, of the PCPs which connect into the backplane may be increased. Alternatively, the backplane may be used in a midplane configuration.

Further, the dual positioning allows for easy access to connect to the connectors of the OAM&P module while allowing the OAM&P module to be tucked out of the way when new connections are not being made.

Preferred embodiments of the invention will now be described with reference to the attached drawings in which:

FIG. 1 depicts an isometric view of a shelf for housing PCPs in accordance with an embodiment of the present invention;

FIGS. 2A 2 B and 2 C respectively depict an isometric front view, a front view, and an isometric rear view of an OAM&P connector module in accordance with an embodiment of the present invention;

FIG. 3 depicts a partial cross-sectional view through line 3 — 3 of FIG. 1; and

FIG. 4 depicts an enlarged partial isometric view of the OAM&P module positioned flush against the left side of the shelf in accordance with an embodiment of the present invention.

FIG. 1 shows a shelf 10 for housing PCPs, which may be part of a telephone switching-system. It has an.open front 11 with a left side panel 12 and a right side panel 14 extending along the sides of the open front from a rear to a front of the shelf 10 to define a shelf space 13 . A front cover 16 provides electromagnetic interference (EMI) protection to the otherwise open shelf 10 . The front cover 16 is hinged to the shelf 10 at a lower end by hinges 18 . An air vent 20 is attached to the shelf 10 above the front cover 16 . The air vent 20 has openings defined therethrough which allows airflow from the interior of the shelf 10 when the front cover 16 is in the closed position (i.e. rotated upward to cover the open front 11 ). An air deflector 22 deflects. air which exits the shelf 10 after travelling upwards through the shelf 10 .

At the front of the shelf 10 is a fiber guide 38 . Also utilized for the positioning of fiber are a fiber bracket 44 , fiber guides 46 and fiber guides 48 . At the rear of the top of the shelf 10 are I/O connector modules. The examples of such modules depicted in FIG. 1 are coaxial cable connector modules 30 , an RJ45 connector module 33 and a champ connector module 32 .

In the interior of the shelf 10 is a lower cross member 42 which, along with a similar upper cross member (not shown), is used to create a plurality of side-by-side receiving stations which guide PCPs into and hold PCPs within the shelf 10 . Positioned in the left most of these receiving stations is a backplane extender card 50 . The backplane extender card 50 is a printed circuit board and has a plurality of visual indicators 51 , typically light emitting diodes, which indicate the status of some of the OAM&P functions of the shelf 10 . A plurality of lenses 17 in the front cover 16 allow the status of the visual indicators 51 to be seen when the front cover 16 is in the closed position.

Mounted on the left side panel 12 and the right side panel 14 are mounting brackets 26 . The mounting bracket on the right side panel 14 cannot be seen in FIG. 1 . The mounting brackets 26 are used to mount the shelf 10 into a rack of a service provider. On an exterior face of the left side panel 12 and forwardly of the mounting bracket 26 is an OAM&P module 52 in accordance with the present invention. The OAM&P module 52 is electrically connected to the backplane extender card 50 through a hole 59 in the left side panel 12 . In FIG. 1, the OAM&P module 52 is shown to be partially rotated forward on a hinge 54 such that it extends sideways from the left side panel 12 of the shelf 10 . This substantially forward facing position is the first of two relative positions in which the OAM&P module is positioned for operation. A pair of screws 56 are used to secure the OAM&P module 52 to the left side panel 12 and are normally secured to the left side panel 12 . A second pair of screws 58 are fastened to the left side panel 12 only when the OAM&P module 52 is secured flush against the left side panel 12 . When the OAM&P module 52 is rotated forwardly, as shown in FIG. 1, the pair of screws 58 are not engaged with the left side panel 12 . Other means, other than a hinge, may be used to move between the first position and the second position.

The details of the OAM&P module 52 can be seen in FIGS. 2A through 2C. The OAM&P module 52 is comprised of a PCB 60 held in a frame 62 . The PCB 60 is sandwiched between the frame 62 and a plexi-glass plate 66 and held in place by a plurality of screws 64 .

On the front face of the PCB 60 are connectors used for the OAM&P functionality of the OAM&P module 52 . Specifically, there are a plurality of wire bonding posts 68 . The plexi-glass plate 66 is present to protect the installer's hands when holding the OAM&P module 52 during wire wrapping on the wire bonding posts 68 . There are also three RJ45 connectors 70 , a fan connector 72 , a TBOS (Telemetry Byte Oriented Serial) D-Sub connector 74 , and two input timing reference interface connectors 76 . Although this collection of connectors are described in the present embodiment, any set of OAM&P connectors which are required by a service provider may be used.

Also present on the frame 62 is a wire bonding strain relief post 78 . Wires which are wire wrapped around the wire bonding posts 68 are first threaded through the wire bonding strain relief post 78 to reduce strain on the wire wrap connections.

The frame 62 is connected by the hinge 54 to a securing plate 80 . The screws 56 are held by the securing plate 80 while screws 58 are held by the frame 62 . Extending from a side of the PCB 60 adjacent the securing plate 80 , is a flexible extension 82 . The PCB 60 and the flexible extension (flexi-cable) 82 may typically be comprised of copper electrical traces held within a resin structure. The flexible extension 82 is held against the securing plate 80 by a plate 84 held in place by a pair of screws 86 . The flexible extension 82 is folded around such that the front of a connector 88 which is connected to the flexible extension 82 is rear facing. The connector 88 is used to electrically connect the OAM&P module 52 to the backplane extender card 50 (not shown in this figure).

FIG. 3 shows how the flexible extension 82 and the connector 88 electrically connect the OAM&P module 52 to the backplane extender card 50 .

At the rear of the lower cross member 42 is located a backplane 90 . Attached to a front face of the backplane 90 are a plurality of edge connectors 92 . Inserted into the left most of the edge connectors 92 is an edge connector 94 . The edge connector 94 is electrically and mechanically connected to the backplane extender card 50 . The edge connector 92 and the edge connector 94 are adapted to mate and electrically connect the backplane extender card 50 to the backplane 90 . The backplane extender card 50 extends forwardly substantially perpendicular to the backplane 90 to a point forward of mounting bracket 26 .

Also situated forwardly of the mounting bracket 26 and rearwardly of the front cover 16 is the OAM&P module 52 . Top views of the wire bonding posts 68 and the connectors 70 and 72 are visible in FIG. 3 . The PCB 60 is held against the frame 62 by the screws 64 . At the edge of the OAM&P module 52 closest to the left side panel 12 , the hinge 54 connects to the securing plate 80 . The securing plate 80 is connected to left side panel 12 by the screws 56 . The flexible extension 82 extends through the left side panel 12 and is held against the securing plate 80 by the plate 84 . The flexible extension 82 is electrically connected to the backplane extender card 50 by the mating of the connector 88 on the flexible extension 82 and a connector 100 on the left face of the backplane extender 50 . Thus the wire bonding posts 68 and the connectors 70 , 72 , 74 (not shown in this figure), and 76 (not shown in this figure) are electrically connected to the backplane 90 through the PCB 60 , the flexible extension 82 , the connector 88 , the connector 100 , the backplane extender card 50 , the edge connector 94 and the left most of the edge connectors 92 . The OAM&P module 52 may be removed and replaced by disconnecting the connector 88 from the connector 100 and unscrewing the screws 56 and the screws 58 , if secured, from the left side panel 12 .

The flexible extension 82 permits the rotation of the OAM&P module 52 to be accommodated without interfering with the electrical connection between the OAM&P module 52 and the shelf 10 . In particular, the flexible extension 82 is both flexible enough and long enough to maintain the electrical connection throughout the rotation of the OAM&P module 52 from a position flush against the left side panel 12 to a position where the OAM&P module 52 extends sideways from the left side panel 12 .

Although the backplane extender card 50 is used in the present embodiment, the backplane extender card 50 may be eliminated where the flexible extension 82 is designed to be long enough to reach the backplane 90 directly and the connector 88 is adapted to connect to the left most of edge connectors 92 .

Additionally, although the present embodiment is directed to the use of a backplane at the rear of the shelf, the backplane may alternatively be used in a midplane configuration at an intermediate location in the shelf. In such a configuration, the backplane extender card may either extend forwardly or rearwardly.

The position of the OAM&P module 52 depicted in the FIGS. 1 and 3, namely the OAM&P module 52 being positioned to be forward facing and including other positions where the OAM&P module is rotated further forward, is the positioning normally used for making connections to the OAM&P module 52 . Although the present embodiment depicts the OAM&P module 52 as being forward facing, the OAM&P module 52 could also be designed to be rearward facing.

In FIG. 4 the OAM&P module 52 is depicted in the second position in which it is intended to be used. The OAM&P module 52 is positioned flush against the left side panel 12 and the screws 58 are engaged with the left side panel 12 to hold the OAM&P module 52 against the left side panel 12 . This positioning is used when it is desirable to move the OAM&P module 52 out of the way. In the present embodiment, this position allows access to the mounting bracket 26 . However, in other embodiments, other components may be rearward of the OAM&P module 52 .

Other than the PCBs and the connectors, the components of shelf 10 are generally of a steel alloy construction.

The above description of embodiments should not be interpreted in any limiting manner since variations and refinements can be made without departing from the spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.