Wurlitzer Style 17 (Regular) PianOrchestra
Philipps Pianella Model Special
Feeder (Pump) Bellows

(Photographs courtesy of David Ramey, Jr.)

The wind-pressure spill valve unit is at right (attached to the side of the pressure reservoir). It consists of a large, hinged pallet valve topside a hollowed out block of wood. This valve is pulled open to relieve excess pressurized air whenever the reservoir reaches a predetermined fill point. When the PianOrchestra is triggered into rewind mode the vacuum flushing valve, also a large pallet valve (not visible in the photograph) but located on top of the vacuum reservoir, abruptly opens, thereby neutralizing any air pressure differential within it. This allows the spring loaded vacuum reservoir to fully relax (or open), which then, in turn, pulls on the wire link between the fully open vacuum reservoir and the wind-pressure spill valve, thereby also releasing any wind-pressure. During rewind the feeder bellows continue to function normally, but with the vacuum flushing valve and wind-pressure spill valve both open, air merely cycles aimlessly through the bellows with little or no useful pressure differential produced.

(Photographs courtesy of David Ramey, Jr.)

The vacuum flushing valve is located on top of the vacuum reservoir. It is nothing more than a simple but large pallet valve that is physically connected by a chain (originally by some sort of flexible cord) to the long horizontal wooden lever located just above the valve chest shelf. This lever has a pivot point (not visible in this image) and when the short end of the lever is pushed down by a projecting metal pin on the rewind hook linkage the long end of the lever is raised, and so by means of the connecting chain the vacuum flushing valve is pulled open.

(Photographs courtesy of David Ramey, Jr.)

This internal view of the wind-pressure reservoir, with the top cover removed, shows the arrangement of the reinforcing gussets glued to the inside surface of the flexible leather covering. The gussets strengthen the leather in such a way that it easily folds inward along predetermined lines, instead of puffing outward, which would stress the glue joints that hold the leather to the reservoir framework.

(Photographs courtesy of David Ramey, Jr.)

This view inside the wind-pressure reservoir shows the simple one-way pallet valves that admit pressurized air from the wind-pressure bellows. These valves fall closed of their own light weight, and can open with no more than a slight puff of air. The valve in the center is for the bellows chamber nearest and touching the reservoir structure, while the one near the back edge (at far right) is for the bellows chamber underneath and next to the chassis floor.

(Photographs courtesy of David Ramey, Jr.)

The two pump sticks connect the crankshaft with the feeder bellows, with each crank being offset 90 degrees, so as to provide a more even loading on the leather drive belts and electric motor. The set of bellows to the front are for wind-pressure, while the rear set of bellows develop a partial vacuum. The long band-saw cuts on the pump sticks allow the bearing points at each end to be somewhat adjustable. For the crankshaft end the top bearing holes have to be split open wide enough to slip the crankshaft lobe through the end of the stick, and then have the pump stick halves spring back to their rest position sos that the bearing hole fits comfortably snug on the crank throw. For the lower end connecting point of each bellows, a large wood screw serves as the bearing point, which can be inserted without having to force the pump stick halves apart. The small hole drilled at the end of each band-saw cut is to prevent the wood from splitting, by spreading out any potentially "splitting" forces over a wider area.

(Photographs courtesy of David Ramey, Jr.)

This image illustrates how a cut and trimmed leather bellows skin is laid out in preparation for gluing on the various reinforcing gussets. The precise size and location of each gusset is carefully drawn out on the inside surface of the leather. When this is done, each gusset is then glued into its exact position according to the drawn outlines.

(Photographs courtesy of David Ramey, Jr.)

This image shows the internal gussets glued in place. The gussets for PianOrchestras were originally made out of a dense European made cardboard with an interwoven fiber structure that made it very strong, durable, and not subject to layer separation.

(Photographs courtesy of David Ramey, Jr.)

This view shows the red paper seals glued in place. It was common practice to seal the exterior of exposed wood structures of the feeder pump and its reservoirs, as well as gusset reinforced portions of bellows leather, with a coating of glue topped off with a durable red paper.

(Photographs courtesy of David Ramey, Jr.)

In this photograph the fully prepared bellows leather is creased and folded into position, ready for gluing onto the bellows wood framework.

(Photographs courtesy of David Ramey, Jr.)

Here the restoration of the vacuum bellows, the wind-pressure bellows, and the pressure reservoir has been completed, as they stand upright on their hinge-point ends. The next step is to rejoin the two separate sets of bellows, and then mount the pressure reservoir on top of the unified bellows assembly.

(Photographs courtesy of David Ramey, Jr.)

The beautifully restored feeder pump is now basically complete, with both the vacuum and pressure reservoirs attached. All that remains now is to put the access covers back on both reservoirs, and then mount the fully assembled feeder pump back into the PianOrchestra chassis.