摘要 |
A pressure switch having a ball valve or contact mounted in an internal chamber to move in response to predetermined relatively high and relatively low fluid pressures in an inlet that opens into the chamber to make or break an electrical circuit through the switch and that incorporates a one-piece sealing element that is constantly exposed to the fluid pressure and is uniquely formed and cooperative with the ball contact and with the walls of the chamber to prevent leakage of the fluid from the chamber effectively without significantly interfering with free unobstructive movement of the ball contact in use. |