Draft model 02 - Communicating vessel to 1 pipe pressure

If there are too many organs in the wall of the box, the weight of the box will become heavier and the storage space will be reduced. And the small damage to the internal structure causes the box to no longer be opened,

So I thought about a simpler mechanism that can be installed in the wall to achieve this goal. Because the box can be opened and must be able to be re-locked, bear in mind that it needs to be resilient. So I set up a sliding box opening, which is locked by an open round tube as a bolt, and rainwater flows into the round tube. A spring or a rubber material arranged at the bottom of the round tube reaches a fixed position through a hydraulic device. The latch is released and the box can be opened.