[OSM-talk] Is anyone able to share image of a bump gate?
osm-talk at mx-server.de
Thu Apr 15 20:19:41 UTC 2021
> I am looking for images of bump gates, available on open license
I've added an illustration of a bump gate.
This image was published in an US patent in 1954. AFAIK US patents
published before March 1989 are in Public Domain, as long as they don't
contain a specific copyright notice, which the source patent does not have.
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