Two Or More Plural-contact Coupling Parts Combined In One Integral Unit Patents (Class 439/638)
- Plug having surrounding screw-thread-coupling contact (Class 439/642)
- Receptacle having internal screw-thread-coupling contact combined with plug having spaced, longitudinally engaging, prong-like contacts (Class 439/647)
- Plural receptacles with each having screw-thread-coupling contact (Class 439/648)