KJT travel switch, position switch (also known as limit switch) of a kind, is a commonly used small current master electrical appliances. The collision of the moving parts of the production machinery is utilized to make its contact action to realize the connection or disconnection of the control circuit to achieve a certain control purpose. Usually, these switches are used to limit the position or travel of mechanical movement, so that the movement of machinery according to a certain position or travel automatically stop, reverse movement, variable speed movement or automatic round-trip movement.