Abstract: A flame containment and suppression baffle architecture for a card cage of an electronic circuit cabinet includes a baffle structure having a pivotable flap that is retained by a meltable solder attachment in an open position, that normally allows cooling air, either convection or forced fed, to exit the card cage housing. In the event of a fire in the card cage, any flame or heat therefrom is steered by a set of guide rails along a canted baffle deflector, to the solder attachment. This focusing of heat upon the solder attachment causes the solder to melt quickly, so that the flap is released and rotates downwardly to a second (vertical) position against the air vents, closing the only exit for the flame and smoke. Smoke soon backs up until it starves the flame of oxygen and extinguishes the flame. Where the card cage is equipped with a forced air system, a microswitch may be located above the baffle roof with its actuator passing through a slot in the baffle and resting on the flap.

Abstract: A printed circuit board card cage contains upper and lower perforated sheet metal plates, having a plurality of mutually opposed staggered patterns of bumps, that are configured to form guide channels for guiding printed circuit boards into engagement with respective card slot backplane connectors, thereby eliminating the need for attachment of a separate set of card guides. The patterns of card guide bumps or ‘upsets’ are arranged so as to direct, yet constrain, the travel paths of printed circuit boards from their points of insertion through grooves in rails at the front of the chassis to the backplane connectors, while providing minimal interruption of a gridwork of cooling air flow perforations through the sheet metal plates. The upsets themselves do not penetrate the sheet metal plates, and the size of the perforations are such that there are no EMI leaks, thus eliminating the need for and assembly of additional perforated plates.

Abstract: A centralized cross-connect (DS0)-time slot routing scheme for multiple bandwidth communication circuit cards is executed by a supervisory control card installed in a distributed backplane of a time division multiplex (TDM)-based communication system equipment shelf. The distributed backplane supports a plurality of TDM time slots, and has a plurality of card slots in which communication circuits cards are installed. A relational database provides a transport association among the TDM time slots of the backplane and DS0 communication channels of communication circuits cards that allows any DS0 communication channel of any port of any communication circuit card to be associated with any TDM communication transport time slot of the backplane. The supervisory control card controls the transport of DS0 communication channels in selected TDM communication transport time slots in accordance with the contents of the relational database.