Private post/Steinway Tone Bell

[John Hartman]

Looks like Dale answered this one . Here is a photo of the bottom of a B 
soundboard:

[link redacted at request of site owner - Jul 25, 2015]

Erwinspiano@aol.com wrote:
> In a message dated 10/17/2003 3:48:32 AM Pacific Daylight Time, 
> michael@gambles.fsnet.co.uk writes:
> 
>     Hello John Hartman
>     You've got a really good thread going here - I hope you don't mind me
>     joining in a bit? My model "A" has, what the London Steinway people
>     call a
>     "Tone Bell". Is this what you are calling the "Pulsator"? It can be
>     seen to
>     be there by simply looking at the frame on the treble side. There
>     you will
>     see, or will not see the square head of what apperas to be a large
>     "carriage
>     bolt". Looking underneath the piano there is this inverted conical
>     casting.
>     I note in my rounds that it is only the Steinways with the
>     "Sostenuto" pedal
>     which has this feature - be it an 85 note or an 88 note keyboard.
>     As to creating a new piano from scratch I leave that sort of think
>     to that
>     Italian chap Fazioli (I think that's his name) Anyone had experience of
>     these "wunder-pianos"?
>     Regards
>     Michael G (UK)
> 
>        Michael
>      The tone bell &  pulsator I asked John about are not the same 
> thing. The pulsator is merely a thin strip of maple about 25 mm wide by 
> 7 mm thick by 6 cm long. Depending on the year this feature intersects 3 
> to 5 ribs. Looking under the piano at the board of a S&S B & C you'll 
> see it in the bass corner. It runs 90 Degrees to the ribs and is 
> glued/dowelled to the ribs. The ribs are also thinned out & seem to 
> terminate somewhat at this point even thought he thinned out flatter 
> portions extend to & are glued into notches in the rasten/inner rim. As 
> John said it appears to be an idea that functions like a cutoff bar but 
> I'm thinking it may have an effect hard to quantify. Surely they had a 
> reason.
>   The bell is just a plate stiffening device. A short beam from the 
> belly rail to the case in the same area would allow for another nose 
> bolt that could take the place of the bell. I cant say the bell has any 
> effect in and of itself to influence tone but does stiffen the plate web 
> where it attaches thereby influencing tone. There must be a modest down 
> force of the bell bolt to do so which by the way will increase the 
> downbearing a small amount (tone effect) These bolts also seem to come 
> loose from time to time and cause a weird rattle.
>  Does that help?--Dale



-- 
John Hartman RPT

John Hartman Pianos
[link redacted at request of site owner - Jul 25, 2015]
Rebuilding Steinway and Mason & Hamlin
Grand Pianos Since 1979

Piano Technicians Journal
Journal Illustrator/Contributing Editor
[link redacted at request of site owner - Jul 25, 2015]