| 摘要 |
The present invention relates to improvements in and relating to water closet cisterns. In the invention there is provided a flush mechanism for a cistern (1) of the type comprising a vertically mounted and movable stem (2) with valve means (3) at the lower end thereof, wherein a bell (5) having an open lower end is fixed coaxially on the stem (2) below the high water level (6) in the cistern (1) and means (8, 9) are provided for the optional introduction of air into the upper part of the bell (5) so as to allow water to drain from the mouth of the bell (5) as the water level in the cistern (1) falls, the arrangement being such that when air is not introduced into the bell (5), the mass of water retained within the bell (5) is sufficient to displace the stem (2) downwards and cause closure of the valve means (3) prior to discharge of the entire water content of the cistern (1). By use of such a bell (5) as a variable weight on the stem (2), it is possible to ensure that the stem (2) is urged downwards as the water level in the cistern (1) falls below the bell (5) or optionally when the bell (5) is allowed to drain, to ensure that the complete contents of the cistern (1) is discharged before the stem (2) sinks to its original position. |
