| 摘要 |
An automatic liquid delivery apparatus (12) which employs no moving parts and requires no external source of energy except gravity to operate, dispenses liquid from a constantly available source (10) which is open to the atmosphere, to a receiver (13) or zone requiring liquid in response to a detector (14) which is located in the zone and initiates discharge of the liquid. The apparatus (12) includes a valve device which retains liquid against discharge from a container or supply by air pressure confined in a space (28) in a passage. The valve device delivers liquid through the passage (40) when air in the space is released by a control device, a detecting mechanism or other automatic operating element. The detecting mechanism (14) can sense the moisture level in soil, in liquid, in roots growing in moist air, in plant tissues or any other location where moisture differentials can be detected. |
