Fyffytr1 asked:
> I have several brass tent rope tensioners, some with the Nov.30, 80 (1880) patent mark and some without.
> My questions are, were they all military issue and when did they stop being produced?
As the US Patent date on the version in your photo shows, it was invented and patented in 1880 (by Mr. E.B. Thompson). The US Army did not adopt it for issue/use until 1889. That fact rather strongly indicates civilians were buying and using these Thompson's Patent "tent-slip" tent rope adjusters in a large enough quantity to keep them in-production during the 9 years until the US Army started ordering vast quantities in 1889.
Sidenote 1:
Mr. Thompson renewed his "tent-slip" Patent just before the original (1880) one expired, in 1896. Thus, some are marked with the renewal-date in addition to having the 1880 date on them. See the photo below. (With appreciation, I give credit to Creskol for first posting that pic here in the What Is It? forum, several years ago.)
Sidenote 2:
When the US Patent expires, anybody can manufacture and sell the object, which no longer needs to be Patent-marked. So, the ones we dig which are unmarked were manufactured 17 years or more (1913 and later) after Mr. Thompson's 1896 renewal of his original patent expired. I dug an unmarked one in a World War One training site near Fort Fisher NC. Also, fellow T-Net relicdigger Metaldiggr reported (above) that he found some in a 1933-44 Civilian Conservation Corp site. And now, Charlie P. has reported seeing "similar" ones on Korean War Era army tents, and he mentions they (or a close approximation of them) may still be for sale.
