Patent ID: 8240368

Claim:
An all-ceramic slidable ball joint assembly for use in an all-ceramic, air-to-air, indirect heat exchanger, said ball joint assembly comprising in combination (I) a spherical body having an outer surface and an inner surface and having a near side and a tube side, said near side and tube side having a center point, said near side having a truncated face to form a flat surface on said near side; said spherical body having an opening of essentially uniform size and a predetermined length through said center point from the near side through the tube side, said tube side having a truncated face to form a flat surface on said tube side; said outer surface of said spherical body being covered with a thin, soft, woven, ceramic fabric; and, (II) a ceramic tube, said ceramic tube having a predetermined outside diameter which is larger in diameter than said spherical body opening, said ceramic tube having an end that is smaller in diameter than the diameter of the ceramic tube, wherein the reduced diameter end of the ceramic tube is insertable into said opening of the spherical body, the length of the smaller diameter on said end being equivalent to the predetermined length of the spherical body opening.