Hi All, "Duplex Pumper" sounds like a player piano that was designed
to be pumped by two people -- wouldn't that be interesting. But alas,
it's an exhauster assembly with 'duplex' bellows.
What's a 'duplex' bellows? Well, it's like one big bellow made out
of three pieces of wood instead of just two. Something like this: /I\
(I sent a few pictures to Robbie to be put in the Archives.)
My question: Why?
Some of the facts about the assembly:
The perimeter measurements of the duplex bellows and the regular
bellows are identical. (In other words, the height and width are
identical to those found in the regular Lauter-Humana.)
The span of each reservoir bellow is 1/2" wider than every other
regular Lauter-Humana reservoir bellow. However, the 'inside' board
is 1/2" wide. So the overall capacity of the bellow is virtually
identical to a regular reservoir.
The span of the exhauster bellow is one inch wider than every other
regular Lauter-Humana exhauster bellow. And even though the thickness
of the 'inside' board is only 5/8", the throw of the pedal assembly is
identical to that of a regular assembly. So again, overall usable
capacity is virtually identical to that of a regular exhauster bellow.
Also, unlike a regular exhauster assembly, which has one inside flap
and one outside flap for each exhauster bellow, there are two inside
flaps and one outside flap per duplex exhauster bellow.
Next question: Considering that for all intents and purposes the duplex
assembly did not create or use and more vacuum than a regular assembly,
why go to all the trouble (and it is a pain to rebuild) and expense
(and it's more expensive to rebuild) of building such an assembly in
the first place?
And what's more interesting is that a Lauter-Humana in the 39,000 range
has a regular assembly, this one in the 45,000 range has a duplex
assembly, and mine in the 50,000 range has a regular assembly. It's
also interesting to note that other than a little metal plaque that's
tacked on to the assembly, which reads "Duplex Pumper", there is no
other marking on the piano to indicate that it was anything special or
Frankly, I'm at a loss to figure out why a "Duplex Pumper" was invented
or installed. I'm also trying to come up with the 'reasonable
explanations' that the engineer gave to the boss to justify the expense
of re-tooling the exhauster assembly division and increasing parts and
Opinion: It has been suggested by a friend who knows early automobiles
very well that it might have been nothing more than an advertising
gimmick used during a time when competition and the desire to be known
as "the very best" was at its peek. And considering that the Lauter
company was located in Newark, NJ, right across the river from NYC,
I suppose it's possible that the "New and Improved Duplex Pumper" gave
Lauter some 'bragging rights' of a sort. The fact that Lauter returned
to making the regular exhauster assembly just a few short years later
probably points to the fact that the gimmick didn't work, or was, at
best, only mildly successful. Dare I say that other companies quickly
challenged the idea as 'hype', which in turn only served to tarnish the
fine reputation that Lauter enjoyed.
Comments and opinions welcomed.
John A. Tuttle
Brick, NJ, USA