US Patent 7466530 Surge arrester

A surge arrester includes an outer electrode and an other electrode. An electrically conductive contact element is spaced apart from the outer electrode by an air gap. The electrically conductive contact element is pretensioned by a spring mechanism that exerts a spring force on the contact element in the direction towards the outer electrode. An electrically conductive connection is located between the other electrode and the contact element. The air gap between the outer electrode and the contact element is arranged in a tightly enclosed hollow space.