A socket adapter housing has a plurality of line and load blade terminals and jaw contacts. An electrical power disconnect device, mounted in the housing, has contacts switchable between closed and open states, the contacts being serially connected between the line blade terminals and the line jaw contacts....http://www.google.co.uk/patents/US5572396?utm_source=gb-gplus-sharePatent US5572396 - Electric service safety disconnect apparatus with overvoltage and overcurrent protection
