Another in the series of pianos designed without relying on a wooden pinblock such as the Mason & Hamlin screwstringer
and the Baker upright
In this case the tuning pin is a snug fit through a hole in the plate. On the other side of the plate the protruding end of the pin is split and fitted with a wedge, somewhat like an axe handle.
The wedge is driven in just enough to provide the proper friction for tuning.
No wood to break down over time and very stable tuning