Le mardi 28 janvier 2020 06:20:29 UTC+1, AS a écritÂ*:
On Tuesday, January 28, 2020 at 12:10:26 AM UTC-5, Tango Whisky wrote:
Patents run for 20 years, so anything connected to Grob gliders will have expired long ago.

..... unless they get renewed.

Uli
'AS'

You can't renew a patent after 20 years. It becomes public domain, and that's it.