1. Field of the Invention
This invention relates to an air seal for sealingly engaging a printed circuit board to deliver cooled air across electrical components mounted thereon and more particularly to a removable air seal which is easily replaced as it becomes damaged.
2. Description of the Prior Art
It is common practice to mount printed circuit boards in a frame wherein the boards are removably retained in side-by-side array in generally parallel planes. The boards are spaced from one another to provide clearance for the electrical elements that are mounted on each board. Operation of the circuit of each board produces heat, which at least in the generally large arrays of circuit boards, must be dissipated or the components would overheat. Thus, it is also common to direct cooling air between the spatially separated circuit boards to provide a means of removing the heat. Further, it is not uncommon for such array to be used in an environment, such as an airplane, where the amount of cooling air is rather limited and thus its effect must be optimized.
As more clearly explained in reference to the figures describing the prior art, it has been common practice to pre-assemble two adjacent circuit boards in spatially separated orientation with the surfaces of each board on which the electrical components are mounted in facing arrangement. This permits the cooling air to be directed between the two boards to cool the components of each board. The assembled board pairs are then removably mounted in a frame with each pair bridging an elongated opening therein that permits cooling air to be fed therebetween. Flexible seals are provided, between the inner face of the boards and the elongated aperture in the base plate of the frame through which the air flows, to provide a seal between the air opening and the interior space to limit cooling air leakage. However, after repeated removal and replacement of the paired board assembly, as for checking and/or repair, the flexible stationarily mounted seals become damaged to the extent it is necessary to replace them. Heretofore, this has essentially required the replacement of the plate member on which the seals are attached which in turn could result in the removal of all boards and the replacement of all seals even though only the replacement of a few seals is required. Alternatively, the repair could be made by removal of sufficient number of paired circuit boards from the frame to permit replacement of individual seals by forcefully removing the seals from their supposedly permanent attachment to the frame plate and re-gluing new seals in their position, all of which is relatively laborious and time consuming.