| 摘要 |
Screw-down tap in which the closing member is applied against the valve seat by rotatable actuating means having a lower helical ramp. The latter coacts with a helical ramp on the closing member. The closing member has a cylindrical stem which is parallel to the axis of the closing member and extends inside the actuating means. The helical ramp on the closing member surrounds at least a part of the stem.
|
