Patent ID: 7564668

Claim:
Overvoltage protection means for use in power supply, comprising: a housing, a first electrode and at least one second electrode in the housing, an arc chamber between the two electrodes within the housing, and a breakdown spark gap between the two electrodes, an arc forming between the two electrodes when the breakdown spark gap is ignited, wherein at least one outflow and cooling channel is formed in the housing through which hot plasma from the arc chamber can emerge, the at least one outflow and cooling channel extending in a lengthwise direction of the housing and being helical, wherein the housing is formed of two parts arranged coaxially relative to one another, wherein the two housing parts comprise a first, inner housing part that has an external thread and a second, outer housing part that has a corresponding internal thread, and wherein the inner housing part is screwed into the outer housing part, wherein the thread between the inner housing part and the outer housing part forms the at least one outflow and cooling channel, wherein the at least one outflow and cooling channel is substantially longer than the length of the housing, and wherein the external thread and the internal thread have a differing height so as to form an intermediate space therebetween.