Gas filled excess voltage protector having electrodes of non-uniform diameter

Claim 1

A GAS-FILLED EXCESS VOLTAGE PROTECTOR COMPRISING A CONDUCTIVE SLEEVE, TWO CUP-SHAPED METAL END CAPS, TWO CYLINDRICAL INSULATING SPACERS FITTING WITHIN AND HERMETICALLY SEALED TO RESPECTIVE ENDS OF THE SLEEVE ON THE ONE HAND AND THE RESPECTIVE END CAPS ON THE OTHER HAND, WHEREBY SAID SPACERS COOPERATE WITH THE SLEEVE AND END CAPS IN FORMING A SEALED ENCLOSURE, AND TWO INTERNAL ELECTRODES CARRIED BY THE RESPECTIVE END CAPS AND EXTENDING TOWARDS EACH OTHER THROUGH THE SPACERS INTO THE SLEEVE IN WHICH THEY TERMINATE WITH PROTECTIVE GAPS BETWEEN THESE ELECTRODES THEMSELVES, AND BETWEEN EACH OF THEM AND THE SLEEVE WHICH CONSTITUTES A THIRD ELECTRODE, CHARACTERISED IN THAT, AS REGARDS EACH OF THE INTERNAL ELECTRODES OF SELFSUPPORTED PORTION OF ITS LENGTH WHICH EXTENDS TO A POINT SHORT OF THE INNER END OF THE ELECTRODE FROM A POINT WITHIN THE CYLINDRICAL SPACER THROUGH WHICH IT PASSES, HAS A CROSS-SECTION SMALLER THAN THAT OF THE REMAINDER OF THE ELECTRODE AT ITS INNER END AND ALSO SUFFICIENTLY SMALLER THAN THE INTERNAL DIAMETER OF THE SPACER TO BE RADIALLY SPACED FROM THE INNER SURFACE THEREOF.