Originally Posted by Gray fox

I couldn't stop considering the definition of transverse and vibrating shuttle, and ended up here:

https://en.wikipedia.org/wiki/Bobbin_driver

Possibly this is not definitive, but it clarifies things for me. A bullet shuttle on an arcing path is vibrating; a boat shuttle on a straight path is transverse. But that makes the 1890s Hengstenberg-Anker a hybrid, as well as the Singer 48K. It has a straight path, but a bullet shuttle. Curious business, these old machines.

Dianne in Colorado