| 摘要 |
This invention is a device for automatically watering unattended houseplants with ordinary tap water. The device controls the rate of dischar ge of water from a reservoir by means of a replaceable multilayer sandwich-type flow control wafer, which is made of several layers of deformable gasket material, laboratory filtration paper, and thin flexible plastic. The gasket and plastic layers contain designed patterns of through-holes and passages which force the water to flo w over and through the filtration paper to control the rate of release of water fro m the reservoir. The design also uses the filtration paper to remove particles fro m the tap water which could clog the system and stop the flow. Over the course of the watering cycle the water gradually loosens the adhesive bonds between the filtration paper and the plastic, which increases the effective flow area of the filtration paper to partially compensate for the reduction in pressure head which occurs as the reservoir empties, thus keeping the water flow rate more constant over the watering cycle than it would be if controlled only by a simple orifice or filter. The watering device includes registration and compression rings which position and seal the flow control wafer, a concave funnel-like reservoir opening for filling the devicein situ, and a narrow integral spike which supports the device in the plant soil and creates an op en vertical passage which facilitates water penetration deep into the plant's root syste m.
|
