Link Feeder Pumps

(Photograph courtesy of Rusty King)

Front view of an orphaned early Link vacuum and pressure pump with a round belt pulley. The shelf like wooden vacuum header that would normally be mounted above the bellows mechanism has been removed, and the pressure (vacuum exhaust) collector fittings that would be attached underneath each bellows unit are missing. The pump consists of two sets of essentially square bellows, for a total of four bellows. In each set the two bellows are attached to a common central support, with the two individual movable bellow boards connected together by a cast iron plate, one at both the top and bottom. Thus, when one bellow opens the other is closing. In the above example the spacer blocks for the bottom plates (which provide clearance to the pressure manifolds that go under the center of each bellows set) are missing, hence the loosely dangling bottom plates.

The crankshaft connecting "rods" are in fact not rods but complicated "split yoke" castings that straddle the front and back sides of the bellows sets, and attach to a cast bracket on the far or outside surface of the outer most bellows. Along the centerline of the crankshaft is a horizontal metal rail on which wooden guide blocks ride so as to keep the bellows constantly in line and from needlessly flopping around. The offset pin on the pulley is for temporarily attaching the wooden pump stick for a "clean out pump."

(Photograph courtesy of Rusty King)

This top view of an early Link vacuum and pressure pump (with the top vacuum header removed) clearly shows the crankshaft and the odd "split yoke" connecting rods that literally wrap around the each of the duplex bellow assemblies. The crankshaft is brass, and each of the four crankshaft bearings is fitted with its own little oil sump. It is likely that the oil sumps were originally filled with a small amount of waste or soft cording to hold the oil and dribble it out slowly. On the backside of the crankshaft is a small brass link chain sprocket that powers the cone-drive speed transmission for the music roll mechanism.

(Photograph courtesy of Rusty King)

Pressure outlet for a late style Link vacuum and pressure pump. The large brass tee with mounting block is used to capture the exhaust from the underneath side of the left-side bellows, i.e., wind-pressure for blowing pipework, such as violin or flute pipes. The pump's other or right-side bellows would be similarly outfitted, except that instead of a tee it would be fitted with a brass elbow, with a section of rubber hose running between the elbow and tee. Notice the spacing block between the bottom edge of the bellows and the cast iron plate that connects the outer movable boards of each bellow set. This is necessary to allow space for the mounting block that holds the brass tee.

(Photograph courtesy of Rusty King)

Front view of a late style Link vacuum pump equipped with a flat belt pulley. This pump is vacuum only, with no lower pressure collection fittings. This head-on shot clearly shows the metal guide strip that runs the width of the pump assembly and that keep the bellows sets securely in-line with the crankshaft. Adjustable wooden blocks on each outer bellows board are set with a minimum of clearance, so as to keep the bellows properly in line, but not so tight as to cause excessive friction and heat buildup. The off-set pin on the flat belt pulley was used to temporarily connect a clean out pump.

(Photograph courtesy of Rusty King)

This close-up shows of the right side bellows unit on a late Link vacuum pump. Here the rimmed flat belt pulley is evident. More importantly this view shows (at far right) some detail of the swivel bearings to which the "split yoke" connecting rods attach. The cast iron bracket screwed to the outer surface of the bellow has two shoulder screws with a locking nut, one for each half of the connecting rod yoke. Once the "yoke" is in place the shoulder screws can be inserted and locked. The top side of each of the two "yoke" bearing points is drilled and then chamfered to provide oiling holes.

(Photograph courtesy of Rusty King)

Top view of a late Link vacuum pump, which shows the bellows vacuum ports, the crankshaft arrangement with grease cups on each bearing point, and the small brass link chain sprocket for powering the cone-drive speed transmission for the music roll mechanism.

(Photograph courtesy of Rusty King)

This backside view of the late Link vacuum pump shows the general layout more clearly without the cast iron flat belt pulley being in the way. Note the simplicity of the metal guide strip and the adjustable bellows sliding guide blocks. Here the detail of the brass link chain sprocket is unobstructed.

(Photograph courtesy of Rusty King)

This photograph is instructive of the poor care to which many coin pianos were constantly subjected. The crankshaft is in a late style Link pump with grease fittings. The crankshaft lobe at picture center is almost completely worn away, leaving only a small rod like remnant. Look carefully at the center crank throw, and the large circular raised area (from which the little rod projects) that represents the original dimension of the crank bearing surface. It is remarkable that the crankshaft did not break apart at this point, but, at the same time, it is a testament to the durability of Link coin pianos.

Here is some history on this particular Link, circa 1968: The piano was in a restaurant. It was probably quite noisy and Rod Keller, the owner of this and several other establishments in the area, probably heard it banging away and contacted [the late] Ed Freyer.(Flemington, NJ) and eventually convinced Ed to go take a look at it. He put a different pump in it.