Heat exchanger with expansible tube seal

Claim 1

IN A STRUCTURE FOR SUPPORTING TUBES OF A HEAT EXCHANGER IN PREDETERMINED SPACED RELATIONSHIP ONE WITH ANOTHER, THE COMBINATION OF: SPACED FIRST AND SECOND MEMBERS EACH HAVING OPENINGS THERETHROUGH, EACH OF SAID OPENINGS IN SAID FIRST MEMBER BEING IN AXIAL ALIGNMENT WITH A CORRESPONDING OPENING IN SAID SECOND MEMBER TO THEREBY DEFINE PLURAL TUBE RECEIVING PASSAGEWAYS DIMENSIONED TO FREELY RECEIVE A TUBE THERETHROUGH; EXPANSIBLE MEANS ARRANGED BETWEEN SAID FIRST AND SECOND MEMBERS ADJACENT EACH OF SAID TUBE RECEIVING PASSAGEWAYS, EACH OF SAID EXPANSIBLE MEANS FORMING A WALL PORTION OF THE TUBE RECEIVING PASSAGEWAY ASSOCIATED THEREWITH, SAID EXPANSIBLE MEANS COMPRISING AN ELASTOMERIC MATERIAL WHICH EXPANDS WHEN EXPOSED TO HEAT EXCHANGE MEDIUM, SAID EXPANSIBLE MEANS MATERIAL BEING SUBSTANTIALLY UNAFFECTED BY TEMPERATURE CONDITIONS OF SAID HEAT EXCHANGE MEDIUM; AND RELATIVELY RIGID FASTENING MEANS FOR SECURING SAID FIRST MEMBER TO SAID SECOND MEMBER WITH SAID EXPANSIBLE MEANS THEREBETWEEN, SAID FASTENING MEANS ENCOMPASSING THE OUTER PERIPHERY OF SAID EXPANSIBLE MEANS AND FILLING THE SPACE BETWEEN SAID FIRST AND SECOND MEMBERS SO THAT ON EXPOSURE OF SAID EXPANSIBLE MEANS TO SAID HEAT EXCHANGE MEDIUM AND CONCURRENT EXPANSION OF SAID EXPANSIBLE MEANS, SAID EXPANSIBLE MEANS WALL PORTION TIGHTLY GRIPS THE TUBE IN EACH OF SAID PASSAGEWAYS.