Archived posting to the Leica Users Group, 1998/04/27
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Marc,
??? Am I missing something?
I checked Chisum on Patents, and it says that the 1790 Act set the term at 14 years and that the Patent Act of 1836 set the term at 17 years from issuance, where it stayed until the amendment in 1994 changed it to 20 years from filing.
Bob
>>> Marc James Small <msmall@roanoke.infi.net> 04/26 12:01 PM >>>
At 06:29 AM 4/26/98 +0000, Chris Bitmead wrote:
>Since when was it possible to make a bayonet proprietry?
The design of a bayonet mount can be patented; if so, it has the same
protections as do any other patented devices.
Leica patented the original M39 LTM mount in 1931; in later years, Exakta,
Voigtlander, Leica, Hasselblad, Zeiss, Nikon, Canon, &c all patented their
proprietary designs. The life of these is either 20 or 21 years, depending
on national law. The US law was traditionally 21 years, and most of these
were patented here as well as in their home countries to obtain that extra
year of protection.
The Zeiss-designed M42 mount doesn't seem to have ever been patented or, at
the least, I've never seen documentary proof that it was. But it is the
exception: when Zeiss designed the K-mount for Asahi, they ensured that
BOTH Zeiss and Asahi held the patent rights on it.
Marc
msmall@roanoke.infi.net FAX: +540/343-7315
Cha robh bas fir gun ghras fir!