Music Trade Review

Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
THE
MUSIC
TRADE
REVIEW
9
A Discussion As to Whether the Speaking and Non-Speaking Pneumatics
Should Be Operated On a Fluctuating Tension, Or On Two Tensions, One
Fixed and the Other Fluctuating—The Advisability of Working Downward
If we lived in a world where things could be
fashioned slowly and lovingly by their makers,
without need to think of pot-boiling, without
either the fear or the hope of gain, without
aught of necessity save that of making the
things perfect, we should avoid nearly all the
confusion, waste and futility which characterize
the modern industrial age. Most of the stupidi-
ties which discourage the acute thinker or the
energetic reformers alike proceed from the ne-
cessity imposed on us of cutting short the
period of incubation and putting on the market
of the world our inventive productions in an
immature state. It is as true of industry as
of human life that birth is but the beginning. It
is equally true that only actual experience of
daily use in the infinitely variegated conditions
of the world can tell us the real virtues and
the real defects of an invention. But it is
still more true that if it were possible—or,
rather, if we were willing—to restrain our haste
to make money out of our inventions, we should
always be able to avoid much of the confusion,
much of the disappointment and nearly all of
the failure of performance to match promise,
that seem to dog the footsteps of every new and
important device that comes into the world.
In no department of inventive endeavor have
the evil results of premature exploitation been
more apparent than in the realm of music-
pneumatics. The first cabinet players were
dreadfully inadequate in every detail, although
they were undoubtedly conceived as to principle
in a manner substantially correct. In fact, it
is just this that snakes us wish the period of
gestation had been much longer. For the prin-
ciple has been shown to be substantially right,
while the details according to which the prin-
ciple has been worked out have been so often
changed arbitarily and even futilely that nothing
short of general confusion arising from exploita-
tion before the problem has been thought out
can account for the phenomena as we know
them to exist.
There is one element in the applications of
pneumatic principle that affords an excellent
indication of the confusion of thought which
has so long held back the player mechanism
from its full and complete realization. This
relates to the level of pressure on which the
machine is to operate. The player mechanism,
as we all know, has been evolved down to a
type which includes certain specific elements
common to all individuals. These are either
power-producing or power-expending elements.
The latter are broadly to be divided into two
classes, speaking and non-speaking. The speak-
ing elements are the striking pneumatics and
the valves which control them. The non-speak-
ing elements are the roll-driving motor, the ex-
pression pneumatics and such other elements
as automatic-tracking devices, etc. Eliminating
the first great division, or power-producing ele-
ments, which of course comprises what may be
called the bellows system, we have to observe
that the second division, classified into speaking
and non-speaking elements, is in a curious and
anomalous position. For it is obvious that
whereas the non-speaking elements require a
fixed pressure, invariable at all times, for their
right operation, the speaking elements decidedly
need the precise reverse; namely, a fluctuating
pressure, with the fluctuations produced by and
under the immediate control of the person or
agency directing the performance.
We, therefore, have a nice problem in pneu-
matics before us, which has been ignored in
practice by all designers, but which should no
longer be overlooked. When it is understood
and acted on, player design will be much more
efficient and much more highly refined.
The question is whether the speaking and the
non-speaking pneumatics alike should be oper-
ated on a fluctuating tension or on two tensions,
one fixed and one fluctuating. Further, if the
idea of a fixed pressure for the non-speaking
pneumatics be adopted, should it be high or
low? Lastly and most important of all, should
the fluctuations be produced by stepping down
from a fixed high, or up from a minimum low,
tension?
Now the ordinary player operates on the step-
up principle, beginning with no pressure and
rising as high as the foot-pumped bellows will
permit, which is usually no more than two
pounds to the square inch. Designers, of course,
have always recognized the necessity of run-
ning the roll-driving motor on a fixed pres-
sure, and have devised governors for assuring
this. But, so long as the power is stepped up
from a normal zero and constantly tends to fall,
it is plain that the motor must run on very
low pressure and consequently must be of rela-
tively large size. As for the other non-speaking
pneumatics, they are never run on fixed pres-
sure, because special governing apparatus would
be too cumbersome to be practical. Hence, the
advantage of fixed levels for working the non-
speaking pneumatics is only gained in part and
very imperfectly.
Now, where a motor-driven power plant is
used, it is, of course, possible to run all the
non-speaking pneumatics on fixed pressure with-
out any trouble, for if the power plant main-
tains a fixed rate of displacement in the ex-
haust units, it is an easy matter to see that
all the non-speaking elements may work on a
calculated pressure, which may not only remain
constant, but should be as high as possible.
The higher this working pressure is, the smaller
may be the moving parts and the more readily
and rapidly will they operate, an advantage of
the utmost importance in such details as the
sustaining pedal pneumatic.
Likewise it is possible in a motor-driven
mechanism to assure that the speaking elements
shall work by stepping down from a maximum.
That is to say, the pressure level induced by the
bellows system being fixed and high, the full
pressure is the measure of the maximum play-
ing power. All playing powers less intense than
this must be had by artificially stepping down.
All of the above is practicable, but designers,
even yet, have failed to lay hold of the obvious
method of securing the best results under this
plan. The present power-driven player mechan-
ism is simply an ordinary mechanism of the
foot-pump type provided with a rapidly moving
auxiliary exhaust set adjusted to it. The pres-
sure level attained is never greater than can
be attained, momentarily, by foot pumping on a
good and well-designed bellows, and its only
advantage is that it is continuous. Even so,
(Continued on page 10)
Cabinet Profits Pay the Rent
This Is Particularly True At This Time of the Year
Notv is the time to cash on
c a b i n e t s . If you haven't
fortified yourself for the
demand write to Cabinet
headquarters. Be it Cabineis
for Player Rolls or Cabinets
for Talking Machine Records
we can give you what you
want.
Our attractive book tells
the story and our up-to-
date stock sheet shows you
what we can ship in time
for Holiday trade.
No. 609—"ADAM" PLAYER ROLL CABINET
Mahogany Top and Front .
Holds 90 Piano Player Rolls
Do it now and address it—
THE UDELL WORKS
1204 W. 28th Street
INDIANAPOLIS, IND.