Bluthner Patent Action

[Richard Brekne]

    "Abstract", according to Merle Mason, is "the connecting rod, in a
    vertical piano mechanism, running between the wippen and the rear
    end of  the respective key. It is also known as a /sticker/..."

    Tom Cole

Yes... my point exactly. This is not really the role of the combination 
roller (knuckle) and repetition lever that the Bluthner actions so 
called <<abstract>> has.  The only roll it has to play at all as a 
<<connecting rod>> is that of connecting to the hammer shank. It is 
clearly not an abstract in the sense that the word <<sticker>> usually 
(as in always) refers too.

The part is nothing more or less then a repetition arm that has the 
knuckle integrated into it as instead of the Herz/Erard solution of 
integrating the roller into the hammer shank.   The reason being 
obviously that in the Bluthern their is no whippen per se as the jack is 
a stand alone part integrated as part of the key. It also has a 
secondary roll to play as an integrated part of the capstan mechanism.  
In the Herz / Erard the capstan raises the whippen and jack so as to not 
only achieve correct hammer blow, but to (for the properly oriented 
jack/rep lever condition) regulate the equivalent of lost motion between 
the jack and roller. In the Bluthner, blow distance is regulated 
directly by the hammer rest rail instead of the combination jack and rep 
lever that the whippen is. That leaves the jack distance to the roller 
free to be regulated independently from the key itself. Hammer blow is 
given by the hammer rest rail so there is no real capstan roll to be 
played... the jack is simply regulated to give free movement under the 
knuckle much in the same way a capstan does its very different job in 
the Herz/Erard action.

So the term Abstract seems to be to my thinking a poor choice as it 
obviously leads one to think in the direction of the drop action 
<<sticker>> where its real roll is very very much different.  Its a 
replever with the knuckle integrated into it. I'd just call it what it 
is.  A repetition lever.

Cheers
RicB