| 主权项 |
1. A supply valve for an air respirator configured to be attachable to a facepiece, the supply valve comprising:
an inflow port for medium-pressure air from a compressed air supply source; a supply port for the medium-pressure air to the facepiece; and a diaphragm to be activated when internal pressure of the facepiece being worn by the wearer is reduced lower than predetermined pressure, wherein the medium-pressure air is supplied to the facepiece via the supply port when the diaphragm is activated to leave the valve open, wherein: the supply valve for the air respirator further comprises a cylindrical housing and a slider configured to be reciprocally slidable on an inner peripheral surface of the housing in an axial direction of the housing; in the housing, a pilot valve seat is formed on an outer side of one end portion of opposite end portions in the axial direction, and the pilot valve seat is urged by a first spring in a direction directed from an outer side to an inner side of the housing and is coupled to the diaphragm provided on the outer side of the housing, and a main valve seat is formed on an inner side of an opposite end portion of the one end portion, and the inflow port is formed between the opposite end portions; a pilot valve contactable with the pilot valve seat, and a main valve configured to be contactable with the main valve seat are formed in the slider, and the main valve is urged by a second spring in a direction that the main valve is contacted with the main valve seat; when a wearer of the facepiece is in a non-inhalation state, the supply valve of the facepiece under connection with the compressed air supply source is in a neutral state where the pilot valve is contacted with the pilot valve seat, and the main valve is contacted with the main valve seat; and when the wearer is in an inhalation state, the diaphragm is activated in the facepiece , and the pilot valve seat moves in a direction against an urge of the first spring and is spaced away from the pilot valve contacted, whereby leaving the pilot valve open, and the medium-pressure air flowed in from the inflow port by leaving the pilot valve open allows the slider to slide in a direction against an urge of the second spring, and the main valve is spaced away from the main valve seat by sliding the slider in the direction, whereby leaving the main valve open, and the medium-pressure air passes through between the main valve and the main valve seat and flows to the supply port, whereby flowing into the inside of the facepiece. |
