VALVE TYPES & MANUFACTURING TECHNIQUES (xvi) - B7G & B9A VALVE ASSEMBLY RUMBLES ON - PRE SEALING PREPARATION..

Electrode assemblies returned from feeder to parent factory were complete except for the getter and in the case of battery valves, the filament.  In both cases, these components were added at the parent factory, immediately prior to the assemblies being sealed into the envelope and the valve being pumped.   This was to avoid contamination of these labile components which were vacuum stored until useage.

Attachment of the getter is a simple process where a strip of metal ribbon coated with getter material is welded to the stirrup wire at the top of the electrode assembly.   

Insertion of the battery filament however, is a very delicate process, requiring a keen eye and superb hand-eye co-ordination as the filament is intoduced through the top of the assembly.  The filament tab, forms the lower connection between filament and pin.  The spring at the top of the filament is attached to the appropriate conductor to form the second connection,  A complete assembly is shown below as '2' shown with it's attendant envelope having a pumping manifold sprue shown as '1'.