Might be useful:
https://patents.google.com/patent/US20070045319A1/en
[Not for the patent (looks like a BearVault), but for this under Background:]
The Purple Mountain Engineering (PME) “Tahoe” bear canister is made from 6061 aluminum. The canister body is heat treated after assembly, and the top is TIG (Tungsten Inert Gas) welded to the canister body. The cover (lid) is hinged (stainless steel riveted to the top and lid). Closure of the lid is accomplished by a DZUS fastener rated at 600 pounds closure force. As with the other prior art solutions, the Tahoe suffers from several disabilities, including complexity, comparatively high cost and heavy weight (two pounds, six ounces) and small capacity.
https://backpackinglight.yahoogroups.narkive.com/VwSmWMLE/purple-mtn-eng-bear-canister-for-sale
[From 18 years ago, complete with miss-pellings]
… It has the same holding capacity as the Garica can (i.e. approx 730 cu in) but only weighs 2 lbs 6 oz…that’s 6 oz lighter than the Garica. Since it is made of heavy duty aircraft aluminum, it is more slender than the bulky injection-molded plastic Garcia can which has that annoying raised bead running across the middle of the can. The Purple Mtn can has the same snap-lock mechanism as the Wild Ideas Bearikade. Also, it is anodized a metallic magenta color so you can spot it easily (in case a bear rolls it away from original location).
[Followup]
And finally, the Purple Mountain bear can, if it’s really 8” x 12”,
can only have a capacity of 603 cubic inches, not 730 (unless those
dimensions are wrong),and that would actually be correct only if those
were its interior dimensions. The Garcia lists its capacity at 614, I
think, and its dimensions are 8.8” x 12” . The Bearikade Weekender, at
9” x10”, actually has about 630 cubic inches of volume, though they
list it as 650. Usability is a whole ‘nother issue.
[Followup]
Apparently the brand-new price on the Purple Mountain Engineering
all-aluminum anodized some pretty bright color and 6 ounces lighter
(and .8 inch narrower) than the Garcia bear canister and which is
approved (take a breath) is $99.95. About 600 cubic inches. About 2
lbs 6 oz.
https://www.linkedin.com/in/david-thornberry-66334226
CEO
Purple Mountain Engineering, Inc
Jan 2000 – 2006 6 years
Machine Shop and Bear Canister (for backpacking) manufacturer.
https://www.bizapedia.com/ca/purple-mountain-engineering-inc.html
[With contact info for the “registered agent”]
Good luck.
— Rex
PS – PME Tahoe still on the approved list for a few other National Parks, too.