| 摘要 |
The present invention relates to a respirator of the type called a filtering facepiece which is made from a flat pocket of flexible filtering sheet material having a generally tapering shape with an open edge at the larger end of the pocket and a closed end at the smaller end of the pocket. The closed end of the pocket is formed with fold lines defining a generally quadrilateral surface comprising triangular surfaces which are folded to extend inwardly of the pocket, the triangular surfaces facing each other and being, in use, relatively inclined to each other. |
