[pianotech] Player question

John Ross jrpiano at eastlink.ca
Tue Aug 10 14:01:45 MDT 2010


Hi Chuck,
Thank you.
Could you explain what happened when you didn't replace the gusset leather?
John Ross
Windsor, Nova Scotia
On 2010-08-10, at 3:19 PM, Chuck Behm wrote:

> John  - The bellows with gussets are pumping bellows. You'll notice that they are sprung to be closed all the time. When you push on the pedals, you open the bellows, pulling air from the reservoir bellow. Then, when you let back on the pedals, the spring closes the bellows. The flap valve on the inside closes, and the flap valve on the outside opens, allowing the release of air.  If you don't have gussets, the fabric of the bellows cloth will be likely to pop out as well.
> 
> The reservoir bellows is sprung to be open. As the air is drawn out by the pumping bellows, it collapses, sucking the fabric of the bellows inward. If the pedals are pumped less vigorously, the bellows begin to be opened by the inner springs, pulling air from the chest of the player action overhead. The fabric at no time is likely to pop out.
> 
> This is just my impression of how the mechanism works. I know that not replacing the gusset material is not a good idea, in that I tried that once.  Chuck Behm



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