Weather dependent plant watering device - uses expansion of pine block due to humidity to control water supply line

摘要

The automatic plant watering system which operates depending on the weather, employs a sensor (1) to control the water, which consists of a block of pine wood. This is retained inside a frame (6) with a spike at the bottom which is embedded in the earth. The bottom of the block ends above ground level, and carries a pointed fitting (2) which rests on the flexible water tube (3) closing the tube when extended. When dry, the wood contracts and lifts the fitting, allowing water to pass through the tube. The tube carries a small capillary tube (9) which discharges onto a trough (10) nearly half way up the wooden block. After a quantity of water has been dilivered, sufficient water is deposited by the capillary tube onto the trough to wet the block and expand it enough to close the supply tube. An adjusting cap (4) is mounted on top of the frame.