Surge arrester assembly

Claim 1

A two electrode gas tube arrester comprising, (a) an insulating tubular member having a central bore; (b) first conductive end cap means carried on one end of said tubular member and in abutting relationship thereot, said end cap means including a central conductor extending axially thereon through said tubular member to present the free end thereof beyond the other end of said tubular member; (c) second conductive end cap means carried on said other end of said tubulr member, said second end cap means having a portion extending over said free end of said conductor such that an ionization gap is defined therebetween; (d) said second end cap means including a first cylindrical portion bonded to the external surface of said tubular member and a second cylindrical portion of reduced diameter joined thereto by a shoulder portion, and further including a circular portion in juxtaposition to said free end of said conductor, said ionization gap being defined (i) by the space between said conductor free end and said circular portion or (ii) by the space between said conductor and said second reduced diameter portion; (e) said shoulder and said other end of said tubular member defining a clearance therebetween for controlling the size of said first mentioned ionization gap space; (f) said first and second end cap means being joined to said tubular member in gas tight relationship to form a control volume; and (g) ionizable gas in said control volume.