I have had several customers recently ask about tension setting
methods and whether we can supply castings in the appropriate
platinum alloy such as Kretchmer’s S+2. We have supplied castings in
this alloy for years, however, I do not have any on how
to set. I recall that Kretchmer had patented the alloy, but I do not
recall whether the method was patented too. If any Orchidians have
any knowledge about this I would love to be able to share it with my
customers.
Yes he has (or his heirs have ) patents on the tension setting in
heat treatable alloys see US Patents 5188679, 5084108
Both of those patents expired on January 28, 2009. So anyone in the
USA is now is free to make such tension set jewelry as those patents
protected. Anyone outside the USA (baring any foreign patents which I
have NOT looked for) has always been free to make such tension set
jewelry, just not to import it into the USA. Of course, that doesn’t
let anyone off the hook that infringed BEFORE the expiration of the
patents.
However, one cannot use Kretchmer’s platinum-gallium (-palladium)
alloys as spelled out in patents 5,846,352 and 6,562,158 IF (and most
likely it is so) their maintenance fees have been paid (at 3.5 years
for both and also 7.5 years for the first).
If anyone seriously needs the issues sorted out I strongly suggest
connecting with a good Intellectual Property attorney. Don’t hesitate
to read the patents first but concentrate on reading the broadest
claim’s only (Claim 1 only in both cases), they are very specific so
not just any platinum-gallium alloy will infringe and even such
alloys will NOT infringe if the spelled out heat-treating or Vickers
hardness values are not met.
I thought the term of US patents is 20 years from the date of
filing which would give both of those patents a couple more years ?
For patents filed after June 1995, it’s 20 years from filing date.
Prior to that, it’s 17 years from the date of issue or 20 years from
filing, whichever is longer.
Prior to that, it's 17 years from the date of issue or 20 years
from filing, whichever is longer.
Correct enough for this case (as usual the law has some nuances that
are exceptions). And also the law requires the payment of maintenance
fees to keep the patent in force after the conclusion of the 3rd,
7th, and 11th year.
But in this case more specifically, the later of the two patents
(5188679) includes a terminal disclaimer that explicitly disclaims
any period that would normally be included in it’s 17 year term
beyond the date of the 17 year term of the earlier (5084108) patent.
This disclaimer is almost certainly done to avoid “double
patenting,” i.e., getting a second term of protection for the same
thing already patented. Hence, both patents expired January 28, 2009
(or, perhaps unlikely, earlier if their maintenance fees weren’t
paid).