Comment by malfist
6 hours ago
Thats all? What happens if the jar is turned upside down in this case? What if something is set on the lid? What if the jar is with someone heading to a camp site in a 4 wheeler and it is vibrated a lot?
6 hours ago
Thats all? What happens if the jar is turned upside down in this case? What if something is set on the lid? What if the jar is with someone heading to a camp site in a 4 wheeler and it is vibrated a lot?
You have a section of threads that seal or have a gasket. This is simpler than a relief valve that can leak or collect bacteria.
The cap is rigid. Either the threads constrain movement or they don't. A section of threads that allow for movement would still find the overall system constrained by other threading.
The pitch stays the same. The simplest way is tapered threading with a sufficiently deep groove to retain when only the first few threads are engaged. Less simple is a custom male profile that transitions into a squared ACME like profile to let gas leak by.