Patent ID: 7278441
Filing Date: 2007-10-09
Classification: F16K,Y10T

Abstract:
1. A fluid control device comprising a valve case having a fluid channel, a valve element holder upwardly or downwardly movable for holding a valve element for opening or closing the fluid channel, a lower casing provided on an upper portion of the valve case, an upper casing joined to the lower casing, a valve stem disposed in a space defined by the upper and lower casings and having a lower end in bearing contact with the valve element holder and a piston secured to the valve stem, an upper space being formed between and defined by an upper surface of the piston and a lower surface of a top wall of the upper casing, a lower space being formed between and defined by a lower surface of the piston and an upper surface of a bottom wall of the lower casing, the fluid control device being characterized in that a compression coil spring is provided in one of the upper space and the lower space for biasing the piston, a compressed air admitting passageway being in communication with the other of the upper and lower space, such that, when the compression coil spring for biasing the piston is provided in the upper space with the compressed air admitting passageway in communication with the lower space, the fluid control device serves as a fluid control device of the normally closed type wherein the piston is biased downward axially, and when the compression coil spring for biasing the piston is provided in the lower space with the compressed air admitting passageway in communication with the upper space, the fluid control device serves as a fluid control device of the normally open type wherein the piston is biased upward axially, and the normally closed fluid control device and the normally open fluid control device are obtained by using the same valve case, same valve element, same valve element holder, same lower casing, and same upper casing, in configuration, respectively, and by using a different valve stem, different piston and different compression coil spring in configuration, respectively.