Rodgers' Piano Restorations
The Best Piano Rebuilding in the Business
9091 Ox Bow Rd.   North East, PA 16428
Because  I have a great deal of work to do, I am forced to concentrate my efforts on all matters which concern the tasks before me.   Sadly, the telephone has become a constant source of interruptions to the work schedule which consist largely of people seeking free information and telemarketers.   I lose between one and two hours each day to these people when I answer the phone.   Because of this, I have been forced to shut off phone communication so that I can better serve my customers.  In addition, the email spammers have become so thick that I am getting thousands of spams per day.  They are so thick that even spam busting software cannot stop them.  The spam has flooded my email so badly that I can no longer gain access to my own email.  Even after trying a change to the email address, the spammers found us again in a very short time.  Each time I try to access my email I simply get "timed out" because of all the junk that is in the folder.   Although I would love to be able to communicate via email, I have been totally blocked from that venue by these parasites.  If you wish to communicate with me, the best method at this time is to send a letter to the address listed above.  I know this seems slow compared to other rebuilders, but it will be well worth the effort since the quality available here is of the highest order.

How a Player Piano Works

First, we learn about the valve and pneumatic.

Picture #1
Valve Up.jpg (15821 bytes)

The first thing to understand when learning how a player piano works is the action of air pressure.  Look at Picture #1.  You will see that there is a line that is labeled "Pouch."  This picture is a cross section of a player piano valve.  The pouch is actually a round disc of very thin leather which is glued into the valve block.  This pouch acts like a balloon.  When you apply air vacuum to the area above the pouch and normal air pressure beneath, it sucks the pouch into the position shown above. 

Picture #2
Valve Down.jpg (14104 bytes)

In picture #2 you see the position the pouch ends up in when vacuum is underneath the pouch.

Picture #3
Valve Off.jpg (59100 bytes)

Picture #3 is more detailed to show you how the principal explained above takes shape in a player piano.  The shaded areas are areas that are under suction.  The unshaded areas are under normal air pressure.  Suction is supplied to the valve through the channel labeled "Suction."  The bleed (see Pictures #1 and #2) allows this air suction to be continued down under the pouch as well as being above it.  The action of the air causes the pouch to drop down and also causes the valve to be sucked down against a seat that blocks the suction off from the areas above.

Picture #4
Valve On.jpg (57458 bytes)

In Picture #4 we see what happens when a hole in the player piano roll crosses over one of the signal tubes.  Air is allowed to rush up the tube and under the pouch.  The size of the bleed hole is so much smaller than the size of the signal tube that the suction cannot be maintained underneath the pouch.  This causes the air pressure under the pouch to increase thus pushing the pouch up or inflating it.   The action of the pouch forces the valve body up against the upper seat.   (Called the outside seat.)  With the valve blocking the outside air and also uncovering the lower (or inside) seat the suction is allowed to pass on to the pneumatic.   This causes the pneumatic to be sucked shut. 

The pneumatic is a simple device made up of two identical rectangles of wood.  These two pieces of wood are hinged to each other at one end.   Then, with the pieces held so that they form the shape of a "V" air tight cloth is glued all around their perimeter.  The pneumatic is attached to the action of the piano so that when it is sucked shut the note it is connected to will play.  The loudness of the note will depend on the intensity of the vacuum pressure at the time the valve is activated.

Next:  The Bellows

Home Up Bellows

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