Relay apparatus with hermetic seal construction

Claim 1

A HEADER WALL ASSEMBLY FOR USE WITH ELECTRICAL APPARATUS TO MAINTAIN DIFFERENT ATMOSPHERES ON OPPOSITE SIDES THEREOF IN ISOLATION FROM EACH OTHER, COMPRISING A METAL PANEL WITH FRONT AND REAR SIDES AND HAVING AN APERTURE THERETHROUGH, A STEEL ALLOY SLEEVE HAVING AN INNER END IN SAID APERTURE AND BEING BRAZED AROUND THE ENTIRE PERIPHERY THEREOF TO THE PANEL IN HERMETICALLY SEALING RELATION, SAID SLEEVE ALSO HAVING AN OUTER END PROJECTING FROM THE FRONT SIDE OF THE PANEL, A STEEL ALLOY TUBE HAVING A FIRST END DISPOSED CONCENTRICALLY WITHIN SAID SLEEVE AND SPACED THEREFROM AND HAVING A SECOND END PROJECTING FROM THE REAR SIDE OF THE PANEL, A GLASS ANNULUS WITHIN SAID SLEEVE AND SURROUNDING SAID TUBE AND HAVING INNER AND OUTER PERIPHERIES FUSED TO AND INTEGRAL WITH THE TUBE AND SLEEVE RESPECTIVELY, A CONDUCTOR ELEMENT EXTENDING INWARDLY THROUGH THE TUBE AND BEING SOLDERED TO THE TUBE IN HERMETICALLY SEALING RELATION TO PREVENT PASSAGE OF GAS ENDWISE THROUGH THE TUBE, AN INNER INSULATION ON THE CONDUCTOR ELEMENT, A METALLIC BRAID SURROUNDING SAID INNER INSULATION, AN OUTER INSULATION SURROUNDING THE BRAID, THE INSULATIONS AND BRAID PROJECTING INTO THE SLEEVE, A SECOND RIGID METALIC SLEEVE IN TIGHT-FITTING RELATION ON THE OUTER INSULATION AND BEING SOLDERED TO THE BRAID AND INTERFITTED WITH SAID FIRST MENTIONED SLEEVE AND WELDED THERETO IN STATIONARY AND ELECTRICALLY CONDUCTING RELATION.