Heater terminal connections

Claim 1

IN AN ENCLOSURE HEATER UNIT OF THE TYPE HAVING A COMBUSTION CHAMBER ASSEMBLY IN HEAT EXCHANGE RELATIONSHIP WITH THE ENCLOSURE AIR, AND A COMBUSTION PRODUCTS DISCHARGE PASSAGE COMMUNICATING THE COMBUSTION CHAMBER WITH THE OUTSIDE AIR, AN IMPROVED TERMINAL CONNECTION ASSOCIATED WITH THE PASSAGE, COMPRISING A CONDUIT SECURED TO THE UNIT AND COMMUNICATING IN SEALED RELATIONSHIP WITH THE COMBUSTION CHAMBER, A TUBE ON THE UNIT ADJACENT THE CONDUIT AND DEFINING AN ANNULAR RECESS THEREBETWEEN, A SLEEVE ADAPTED TO BE RECEIVED OVER THE CONDUIT AND HAVING AN ANNULAR UPSTANDING FLANGE RECEIVABLE IN THE RECESS, A SEALING ELEMENT IN THE RECESS BETWEEN THE FLANGE AND UNIT, MATING THREADED PORTIONS ON THE CONDUIT AND SLEEVE OPERABLE TO DISPLACE THE SLEEVE AXIALLY OF THE CONDUIT TO COMPRESS THE SEALING ELEMENT BY AND BETWEEN THE FLANGE AND THE UNIT AND RESTRAINED BETWEEN THE CONDUIT AND TUBE, AND A SECOND SLEEVE ANNULARLY OF THE FIRST-MENTIONED SLEEVE AND MATABLE OVER THE TUBE.