Under pressure ring will follow the arc slide axially relative to the button bar

It should be noted, taken from a mechanical manual investigation groove depth is small, if roots unclear bottom pressure in the circular ring will follow the axial sliding movement relative to the button bar, the loss of a ring effect. Therefore, the design of the groove depth should be  power transformers  bigger, processing bottom  air circuit breaker  to clean the root, or simply use the pin structure is more reliable. About flameproof enclosure on the copper sleeve, joysticks require co-ordinated with  circuit breakers , copper sleeve is an interference fit with the housing, and the joystick is a clearance fit. Copper sets the amount of interference should not be too large, should be controlled not more than 0.05mm, copper sleeve wall thickness should not be less than 2.5mm, or assembly problems.