keyboard levelling

[Phillip Ford]

>Hi List,
>This question is obvious to me, but I don't know the history of innovation in
>piano design.
>Has anybody tried a balance rail pin which screws in and out of the balance
>rail, with micro-thread like tuning pins, to adjust it's height.
>A flange at the bottom on which sits one felt punching and then the key,
>which goes up and down when adjusted from the top. Has to be quicker, easier
>and more accurate.
>Bruce Browning-The Piano Tuner.

Yes.  There are several patented ideas like this as well as other 
variations.  One example of the idea that you mention is patent 1,118,939
to G Lawrence on Dec. 1, 1914.  I don't know why none of them
became accepted by the industry.  The idea that you mention
seems like a straightforward way of dealing 
with this, as it involves no other modifications to a conventional 
action.  It also doesn't seem like it should be terribly expensive to 
incorporate.  It also would allow those that think that it's a good idea to 
attempt to duplicate the action force at the capstan with lead weights, 
repeatedly remove keys, and put little colored pieces of paper under them 
to do it that way if they wished.

Phil Ford