| 摘要 |
<p>This invention relates to a headgear construction comprising a shell having fitting means secured within the shell for engagement with the head of the wearer. The fitting means include at least one chamber connected to a source of compressible fluid. Upon placement of the headgear on the head, the source of fluid is engaged by the wearer's head to displace fluid from the reservoir into the chamber. At the same time, means automatically restrict the flow of fluid from the chamber back to the source whereby there is a variation in the dimensions of the head receiving space of the headgear. The wearer can, thus, force a variation in the head receiving space until a comfortable fit is achieved, and then release pressure whereby the size achieved will be automatically retained until the headgear is removed.</p> |
