Early Style Wurlitzer Direct Drive Gear

(Wurlitzer Service Manual image courtesy of Dana Johnson)

This early Pianino (from a Wurlitzer Service Manual) is what a coin piano operator was faced with before the introduction of the patented Wurlitzer Direct Drive Gear system, which happily did away with the cumbersome, service prone flat-belt and countershaft drive arrangement. Notice the difficulty of getting to and adjusting the flat-belt situated behind the various mechanisms and that runs between the countershaft and crankshaft pulley.

(Photograph courtesy of Rusty King)

This early (circa 1911) open gear style Wurlitzer Direct Drive Gear Standard is still quite functional today. The unit stands about 6-3/4" high to the top of the fiber gear. Units like this were used in the early 88-note pianos, such as the Mandolin Quartette, the Mandolin Sextette, and early 65-note pianos. Its appearance looks to be identical to those shown in circa 1906 Wurlitzer catalogues and advertising material. The specimen pictured is installed in Wurlitzer Style IX #16,040, which is shown in the Wurlitzer ledger as being shipped from the factory on September 23, 1911.

Machined surfaces on the separate base casting and the upper cast housing are joined at the center point of the worm gear shaft, with each casting contributing one-half of the cast iron worm gear bearing. Essentially the bearing is a hole bored through the two joined castings. A small oil sump in the base is basically the size of the recess necessary to accommodate the worm gear, holding a small amount of oil that can be soon depleted due to oil seepage through the shaft bearings and then being slung off of the shaft. Note that the original "flexible steel shaft" going between the motor and gear standard has been replaced with a modern component, but otherwise the unit is complete and original to the instrument.

(Photograph courtesy of Dana Johnson)

This short version of the open gear standard is installed in Wurlitzer Style I, No. 17452, a 65-note automatic piano. Here the front crankshaft bearing cap has been removed, revealing the brass bushing and the assortment of bearing cap spacers. These thin metal shims (and sometimes a few paper spacers) are used to adjust the fit of the bearing, so that the shaft turns freely by hand, but without too much play so that the bearing "knocks" when under load.

(Photograph courtesy of Dana Johnson)

This view of the crankshaft bearing cap (from the open gear standard shown above and installed in Wurlitzer Style I, No. 17452) clearly shows the installed brass bushing. These bushing halves normally should fit easily but snugly into the cast iron bearing cap, but not so tightly as to deform it. The oil lubrication hole is in the center of the bushing, which is in line with the oil cup screwed into the top side of the bearing cap. Later units (or early units where the bushings have been replaced) have pot metal bushings, which tend to swell and become brittle with age.

(Photograph courtesy of Dana Johnson)

The tall version of the open gear standard is original to this "bay front" style Pianino, No. 10570. The tall version stands about 8-3/4" tall. The worm gear and fiber gear assemblies are essentially identical to those used in the shorter version. The outstanding visible difference between the "short" and "tall" versions is the much taller, stretched base casting. As is common with Pianinos, the crank stub shaft is pinned and fitted with a 5" O.D. wooden belt pulley. The leather belting going upward is passing through the roll mechanism shelf, and provides power for the the spoolbox.

(Photograph courtesy of Dana Johnson)

Another variation for the open gear standard, which in this case a tall version, also standing about 8-3/4" high, is installed in Pianino No. 19255. Although perhaps not obvious by a quick glance, this specimen has a modified base casting to accommodate the rewind cam and cam following linkage, which is only marginally visible in this picture. The 5" O.D. wooden belt pulley supplies motivating power to the spoolbox located above the worm gear standard and pump area.

(Photograph courtesy of Dana Johnson)

From Pianino No. 18406, this picture (with the wooden pulley removed) shows the cam-follower lever and associated rewind linkages in and around the tall open gear unit. Notice the coil spring to the left of the crankshaft that keeps the cam-follower roller tightly against the triangular cam. The small vertically oriented pneumatic (at picture center) is what pushes the trip lever forward to engage the rewind trip pin at the end of the cam-follower lever. Then, once engaged, the trip lever is forced down, in turn twisting the intermediary shaft that pulls down on the rewind linkages next to the spoolbox located high above.

(Photograph courtesy of Dana Johnson)

This free standing tall open gear standard has been rebuilt and remains to be re-installed in Pianino No. 19255. This view clearly shows the modified base casting, which more or less has had some of the otherwise symmetrical front side whittled away and flattened, so as to accommodate and provide a smooth surface by which to bolt the support lever upon which the cam-follower lever pivots. Although not so obvious, the actual cam is triangular, and is integrally cast as part of the flange that holds the fiber gear. The cam's outward three facing surfaces have been machined smooth. The wooden pulley is clamped around the crankshaft stub shaft, which has a pin running through it so as to keep the pulley from slipping on the stub shaft.