A tempering arrangement for containers, particularly for bottles with photo-developing chemicals, has a tank for accommodating a tempering bath and having an opening for inseting a container, an abutment provided in the tank and engageable with the container in an end position of the latter...
patents.justia.com
There may be others, like design patent on the shape/appearance and I didn't bother looking since nobody else, except
@wiltw, seems to want to do their homework.
BTW, what
@beemermark describes has been true since the beginning of the U.S. Patent agency, and is stated in a lot of documentation throughout the nineteeth century when there was a huge interest/upsurgence in inventing and patenting of inventions.
The ease of "stealing" also depends on the type of patent. Design patents are much more easily "violated" than a utility patent.