The Steinway Bell Patent

[Ron Nossaman]

>One of the functions of the nosebolt--probably their most important 
>function--is to couple the plate to some belly structure and prevent it 
>(the plate) from vibrating. The bell/bolt arrangement is simply another 
>form of nosebolt.
>
>Del


And in an area where the piano would have likely benefited from a beam to 
the belly rail anyway.

Ron N