.
Home Manuals Supplies Videos Consult Technical Testing Contact

How the Notes Play -A Simple Explanation

Chapter 2: The Bellow

While there is no argument about the fact that it is vacuum which makes the player piano work, it is the bellow which uses and creates that vacuum. The average player piano contains one hundred bellows of various sizes and each bellow has its own job. In order to operate correctly, every bellow must be air-tight. Also, every bellow works together with a valve of one sort or another.

Since Chapter 1 dealt with the note, or poppet, valve it seems appropriate to continue with the note bellow, or striker pneumatic. In the drawings below, the bellow is mounted on a "wind chest" which acts as a channel between the valve assembly and the bellow. Typically, the bellow would be mounted on the underside of the wind chest but for purposes of explanation and ease of understanding I have placed it on top.

Referring to Figure 8, when the pouch rises, it pushes the valve (in red) up and closes off the exhaust port. This the entire pneumatic assembly with all it's partsThis allows the vacuum, from the source, to pass through the valve guide into the upper half of the valve assembly and from there into the bellow. As the vacuum sucks the air out of the bellow it collapses and activates a note on the piano. When the pouch relaxes the valve drops back to its starting point and seals off the port through which the vacuum passed and in doing so simultaneously opens the exhaust port allowing outside air to rush in and "fill up" the previously collapsed bellow (see Figure 9). At this point it should be noted that the configuration of the wind chest is a bit more complicated than the drawings indicate. This the entire pneumatic assembly with all it's partsTo begin with, as stated earlier, the bellow is normally mounted on the bottom tier of the wind chest so that when it is activated, or closed, the moveable board will travel in an upward direction pushing on the underside of a key or a tab protruding from the action of the piano. And since the weight of the piano key or the piano action is resting on the moveable board there is a natural tendency for the bellow to return to an open position once the valve is deactivated.




To Be Continued

We Gladly Accept These Cards
Discover, VISA, MasterCard

back to top..To The Top of this Page . . . back to index ..To The HOME Page


This page was last revised February 8, 2013 by John A. Tuttle, who Assumes No Liability
For The Accuracy or Validity of the Statements and/or Opinions
Expressed within the Pages of the Player-Care Domain.
Cartoon Graphics by E7 Style Graphics (Eric Styles)


Since "Player-Care" is an internet business, I prefer that we correspond via E-Mail (click here to fill out the 'Request Form'). However, if I'm not in the middle of some other activity, you can reach me at 732-840-8787. But please understand that during the hours from 8AM-5PM EST (Mon-Sat), I'm generally quite busy. So, I probably won't answer the phone. If you get the answering machine, please leave a detailed message stating the reason for your call. Also, repeat your name and phone number clearly and distinctly. By necessity, I prioritize everything in my life. And, if you call and just leave your name and number, and ask me to call you back, it might be a day or two before I return your call. Why? Because I don't know why you want me to call and I might not be prepared to assist you in an effective and efficient manner. If you leave me an E-Mail address (which I prefer), spell it out phonetically. The more you do to help me, the more I can help you in return. Don't rush. You have four minutes to record your message.


Grand 16 IconGrand 32 Icon

407 19th Ave, Brick, NJ, 08724
Phone Number 732-840-8787
Upright 32 IconUpright 16 Icon
Google Adsense Ad