It somewhat reminds me of https://en.wikipedia.org/wiki/Z1_(computer) although this mechanism is definitely superior in terms of friction. I guess the majority of research into mechanical computers stopped shortly after electrical/relay ones started becoming more interesting, which is why there's definitely better mechanical designs possible.

In fact, people probably use a lot of mechanical devices which can serve as logic gates without knowing it --- although everyone focuses on electronic digital computers, the mechanisms on which computers can be built are surprisingly vast and simple.

Also, the PDF is rather bloaty for the content, because all the figures are extremely high-resolution bitmap images instead of vector graphics, despite looking like they were created with a vector graphics program.