| 摘要 |
A cap for forming a sealed cavity around an end of a fastener has an inner cap 10 terminating at an inner cap rim 18 which surrounds an opening into a central cavity 12 and lies in an inner cap plane 19 around a majority of a circumference of the inner cap 10. An outer cap 20 is fitted over the inner cap 10, the outer cap 20 comprising an outer cap body 21 and a skirt 25 extending from the outer cap body 21 to a skirt rim 26 which lies in or slightly below the inner cap plane 19 around a majority of a circumference of the skirt 25. An annular pocket 34 is provided between the skirt 25 and inner cap 10, and a flow space is provided between the outer cap body 21 and the inner cap 10. The flow space is in fluid communication with the annular pocket 34 so that it can receive a flow of sealing material and feed it into the annular pocket 34. The outer cap body 21 is formed from a first material with a first elastic modulus, and the skirt 25 is formed from a second material with a second elastic modulus which is lower than the first elastic modulus. The skirt 25 flexes as the flow of sealing material is fed into the annular pocket 34 so that the skirt rim 26 lifts up to form a gap between the skirt rim 26 and the structure which enables air to escape the annular pocket 34 by flowing through the gap. |
