| 摘要 |
A face mask has a relatively soft canopy and a more rigid reinforcement member moulded together from different plastics as two shots in a dual-shot moulding process. The peripheral sealing edge of the canopy is tapered to a reduced thickness to increase its flexibility. The reinforcement member is a frame with radially-extending arms supporting respectively a gas port by which gas can enter the mask, a valve that allows air into the mask when there is an inadequate supply at the gas port and a selectively closable vent. The mask is secured to the patient's head by a harness attached to ends of the harness arms. |
