Method of making an electron tube

Claim 1

METHOD OF MAKING AN ELECTRON TUBE COMPRISING THE STEPS OF: (A) SIMULTANEOUSLY FORMING A PLURALITY OF PRELIMINARY SLOTS IN A SIDE PORTION ADJACENT TO ONE END OF A TUBULAR CUP-SHAPED GRID BLANK, SAID SIDE PORTION BEING REMOTE FROM AN EVENTUAL ACTIVE REGION OF THE COMPLETED GRID, AND IN AN INTURNED FLANGE AT SAID ONE END AT LEAST A PREDETERMINED DISTANCE INWARDLY OF THE PERIPHERY OF SAID FLANGE AND LESS THAN A RADIAL DIMENSION OF SAID INTURNED FLANGE, (B) LOOSELY MOUNTING SAID SLOTTED GRID BLANK IN A SUBASSEMBLY COMPRISING SAID BLANK AND A SECOND TUBULAR GRID BLANK WITHIN SAID SLOTTED GRID BLANK, SAID SECOND BLANK HAVING TRANSVERSE DIMENSIONS OF SUCH MAGNITUDE THAT WHEN SAID SECOND BLANK IS IN CONCENTRIC RELATION WITH RESPECT TO SAID SLOTTED BLANK, SAID BLANKS ARE MUTUALLY SPACED SAID PREDETERMINED DISTANCE, (C) INSERTING INTO SOME ONLY, OF SAID SLOTS AND INTO THE SPACE BETWEEN SAID GRIDS IN RADIALLY PARALLEL RELATION WITH RESPECT TO SAID BLANKS, A PLURALITY OF GAUGING MEMBERS EACH HAVING A TRANSVERSE MAGNITUDE SUBSTANTIALLY EQUAL TO SAID DISTANCE, WHEREBY SAID LOOSELY MOUNTED BLANK IS URGED INTO CONCENTRIC RELATION WITH RESPECT TO SAID SECOND BLANK, AND THE CONCENTRICITY MAY BE CHECKED BY VISUAL OBSERVATION THROUGH THE OTHER OF SAID SLOTS, (D) MUTUALLY FIXING SAID GRID BLANKS IN SAID CONCENTRIC RELATION, (E) SIMULTANEOUSLY FORMING AXIALLY PARALLEL SLOTS IN SAID TWO GRID BLANKS IN THE EVENTUALLY ACTIVE REGIONS OF SAID BLANKS AND SUBSTANTIALLY AS CONTINUATIONS OF SAID PRELIMINARY SLOTS, (F) SEALING A TUBULAR ANODE TO SAID SUBASSEMBLY WITH THE EVENTUAL ACTIVE REGIONS THEREOF COEXTENSIVE WITH THE EVENTUAL ACTIVE REGIONS OF THE SLOTTED GRID BLANKS, AND (G) EXTENDING A CATHODE HEATER ASSEMBLY INTO SAID SECOND SLOTTED GRID BLANK IN SUBSTANTIAL RADIAL REGISTER WITH SAID EVENTUAL ACTIVE REGIONS.