Thread: Parautoptic Safe Lock circa 1840s-1850s

Originally Posted by Patent

Hi Doug.
" I remember reading about a similar lock that took the bit and returned it via a little chute *inside* the door. This denied an attacker the chance of examining his false bit for any clue(s) as to why it had failed and alerted the owner to tampering. The true bit could of course be retrieved because the lock would be open. I do not recall mention of any special tool for inserting the bit or turning the lock.

I cannot recall where I read about this, (more than thirty years ago!) but the description has stayed with me and indeed is the reason for my username on this site. It may have been in the "Rudimentary Treatise"

A lock that fits that description is the subject of another Yale US patent, 12,932, that was issued in 1855. This patent uses the same Grasshopper type key.
BBE.

Attachment 2629

BBE:
I do not have a patent number however Doug MacQueen correctly pointed out that the grasshopper lock was patented by William Hall. Attached is a drawing by E.Willis of the grasshopper lock and key.

BBE. William Hall of Boston. Power Proof Lock. Patent number 5686. August, 1st. 1848.
Regards.
Patent.

BBE.
Thanks for the reference to US patent, 12,932. I believe that lock is refered to as Linus Yale's Peanut Key Lock. There is an example in the Mossman collection.
Is anybody aware of the existance of the lock as described in US Patent 10,584.
Thanks.
Patent.

Referring back to the original post and lock, I recently looked at a Edwards and Fernald (Boston) safe with a keyhole setup like the one pictured. One rectangular slot above another rectangular slot. I think I found the patent for that one. The key bit, after it is inserted into its slot (lower), the handle closes a curtain on the key hole and it is forced up against the tumblers. I will double check this info and the patent and post pictures and the patent if it is different than the one already posted.

Originally Posted by Steve Dudley

Attachment 2629

Steve, None of your attachments appear or even seem to exist on the server. Could you please try to upload again ?

Thanks

Thanks to all for the info on these locks, I never knew that there were so many variations on this theme. I have always wondered why a similar system is not common today. Locks working on similar lines would not be difficult to make using modern CNC manufacturing techniques and indeed could use fewer, smaller and more simple parts, use less precise lever packs etc. if the levers were not available for manipulation. Or have I missed something? Being an amateur I probably haven`t spotted a major flaw in the whole idea....

I am unable to send any pics today but the patent which seems to fit the lock pictured in the first post is by M.R. Stephenson 9,126 Jul 13, 1852.

I will try to figure out what I'm doing wrong with my photo's





I tryed to upload one at a time. This is my key and a drawiing of lock