Contactor and general switching device comprised thereof

A contactor, comprising:

• an enclosed space containing a liquid or a gas arc extinguishing medium or a vacuum;
• and
• a movable contact head separates the enclosed space into two chambers, wherein at least one of the two chambers is provided with a static contact head, at least one contact unit of the static contact head one to one aligns with at least one contact unit of the movable contact head forming at least one arc gap, the at least one contact unit of the movable contact head is hollow enabling the two chambers to communicate;
• wherein the movable contact head reciprocates, the at least one contact unit of the movable contact head is receivably engaged with and disengaged from the at least one contact unit of the static contact head, the two chambers are alternately compressed and expanded, wherein the liquid or the gas arc extinguishing medium rushes into the at least one arc gap back and forth through the hollow of the at least one contact unit of the movable contact head, and circulates between the two chambers, providing the contactor and a self-circulating reciprocal synchronous arc extinguishing pump to implement turning ON, OFF of the contactor and synchronous arc extinguishing thereof.