For others reading this thread, here are some links regarding the PCT patents mentioned by Z7E:
1) https://www.wipo.int/pct/en/
2) https://patentscope.wipo.int/search/en/search.jsf

Here is a starting point for searching existing patents in the United States, including a seven-step strategy:
https://www(dot)uspto(dot)gov/patents/search
https://www(dot)uspto(dot)gov/learning-and-resources/support-centers/patent-and-trademark-resource-centers-ptrc/resources/seven

Searching the patents is fascinating:
- some of the products and ideas are futuristic and/or complicated,
- others are elegantly simple and clever improvements on everyday items,
- a few cause me to wonder how a patent could have been granted!