Music Trade Review
Issue: 1922 Vol. 74 N. 8 - Page 9
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FEBRUARY 25,
1922
THE MUSIC TRADE REVIEW
Those Interested in Perfecting and Refining the Player-piano, From a Me-
chanical Standpoint, Can Find Much Room for Experimentation in the Field
of Motor Design—Some Improvements Easily Possible of Accomplishment
In the course of a fairly lengthy experience in
the player business, taken largely upon its engi-
neering side, the writer has had occasion to note
how little change has been made in the design of
the wind-motor and of its transmission gears.
Part of this state of affairs may indeed be ac-
counted for by the fact that the early designs of
motors and transmission gears were remarkably
sound considering the inexperience of the design-
ers, so that it has not seemed necessary to make
frequent changes. Yet there are certain con-
siderations in the case which ought to receive
more attention than in general they do receive at
the present time.
Power Consumption Fifty Per Cent
For one thing, it is not usually remembered
that the ordinary wind motor absorbs about one-
half the effort put in at the foot-treadles, or by
the power-pumping arrangement, whichever is
used. Tn some cases the proportion is more
nearly three-fifths than one-half. Incredible as
this statement may appear, it is nevertheless
demonstrably true. In these columns there was
once published a series of curve tracings show-
ing current fluctuations graphically recorded by
a watt-meter attached to an electric motor which
was running the power-plant of a player-piano
of standard make. The meter showed plainly
that the current consumption needed to supply
power to run a music roll silently was never less
than one-half of the consumption required for
playing the same roll, the average speed in both
cases being the same. It must be plain that this
constitutes a weakness in the design of the
player-piano. It is, in fact, a serious weakness
and one which calls for immediate remedy.
A good deal of such dissatisfaction as has been
voiced regarding the foot-expression player-piano
is to be traced to this wastefulness of the wind
motor. If that motor were less energetic in con-
suming power the job of "pedipulating" would be
much less laborious and there would be much
less excuse for the cry that the people do not
want to "pump." Moreover, any gain in motor
economy is also a gain in playing power, for the
same effort would mean, in the improved condi-
tions, less continuity of effort and consequently
less fatigue, with simultaneously greater power
available for the purpose of sounding the tones.
The Leakage Tendency
Designers of motors have been very conserva-
tive. The first motors were indeed well and care-
fully made. They represented the embodiment
of a well-conceived idea and they have retained
their hold to this day, with alterations only in
details of construction. Yet it must be evident
that, successful as they are in a rough and ready
fashion, simple as they are and easy to "make,
silent and durable as they undoubtedly are, much
remains to be done before they can be called
satisfactory from an engineering standpoint. The
principal trouble with them lies, of course, in
their tendency to leakage at the joints. The
sliding valves do not maintain against the inter-
nal vacuum anything like tight joints, and indeed
it is impossible that they should. The leather
leaves of the motor units crack and leak. The
transmission gums up, clogs, drags and wears at
the gears.
The Gulbransen Engine
One of the finest examples of good motor con-
struction was the Gulbransen engine motor. This
was built of metal in the form of a three-cylinder
double-acting marine engine, with pistons, pistor.
rods and a highly effective rocking-valve gear
The consumption of power certainly did not ex-
ceed one-half the consumption of the wooden
bellows engine. The control was perfect and
the power very great. The latest of these en-
gines was built with a single rotary valve, which
made the timing perfect and was even more eco-
nomical than the original type. We have always
believed that this motor, though it was finally
abandoned, was the most economical and power-
ful ever designed. It certainly excelled as an
engineering work and was undoubtedly sound in
principle.
Without a doubt there ought to be a recon-
sideration of the motor in respect of its general
design. It is absurd that the mere task of turn-
ing the music roll should absorb one-half or
more of the total power-producing capacities of
the bellows. And if this fact were more generally
realized there would soon be an improvement, or
at least an attempt to produce something better.
That something better can be produced we
have no manner of doubt. The Gulbransen motor
was more costly, of course, than one made in the
(Continued
on pa
is an accomplished fact with
Pratt Read
Player Actions
Our factory is running full force and full
time, producing and shipping more player
actions than at any time prior to the
Armistice.
, .
Over 60 piano manufacturers install them.
The Pratt Read Player Action Co.
Main Office and Factory, Deep River, Conn.
Foreign Office, 21, Mincing Lane, London.
'
FEBRUARY 25,
1922
THE MUSIC TRADE REVIEW
Those Interested in Perfecting and Refining the Player-piano, From a Me-
chanical Standpoint, Can Find Much Room for Experimentation in the Field
of Motor Design—Some Improvements Easily Possible of Accomplishment
In the course of a fairly lengthy experience in
the player business, taken largely upon its engi-
neering side, the writer has had occasion to note
how little change has been made in the design of
the wind-motor and of its transmission gears.
Part of this state of affairs may indeed be ac-
counted for by the fact that the early designs of
motors and transmission gears were remarkably
sound considering the inexperience of the design-
ers, so that it has not seemed necessary to make
frequent changes. Yet there are certain con-
siderations in the case which ought to receive
more attention than in general they do receive at
the present time.
Power Consumption Fifty Per Cent
For one thing, it is not usually remembered
that the ordinary wind motor absorbs about one-
half the effort put in at the foot-treadles, or by
the power-pumping arrangement, whichever is
used. Tn some cases the proportion is more
nearly three-fifths than one-half. Incredible as
this statement may appear, it is nevertheless
demonstrably true. In these columns there was
once published a series of curve tracings show-
ing current fluctuations graphically recorded by
a watt-meter attached to an electric motor which
was running the power-plant of a player-piano
of standard make. The meter showed plainly
that the current consumption needed to supply
power to run a music roll silently was never less
than one-half of the consumption required for
playing the same roll, the average speed in both
cases being the same. It must be plain that this
constitutes a weakness in the design of the
player-piano. It is, in fact, a serious weakness
and one which calls for immediate remedy.
A good deal of such dissatisfaction as has been
voiced regarding the foot-expression player-piano
is to be traced to this wastefulness of the wind
motor. If that motor were less energetic in con-
suming power the job of "pedipulating" would be
much less laborious and there would be much
less excuse for the cry that the people do not
want to "pump." Moreover, any gain in motor
economy is also a gain in playing power, for the
same effort would mean, in the improved condi-
tions, less continuity of effort and consequently
less fatigue, with simultaneously greater power
available for the purpose of sounding the tones.
The Leakage Tendency
Designers of motors have been very conserva-
tive. The first motors were indeed well and care-
fully made. They represented the embodiment
of a well-conceived idea and they have retained
their hold to this day, with alterations only in
details of construction. Yet it must be evident
that, successful as they are in a rough and ready
fashion, simple as they are and easy to "make,
silent and durable as they undoubtedly are, much
remains to be done before they can be called
satisfactory from an engineering standpoint. The
principal trouble with them lies, of course, in
their tendency to leakage at the joints. The
sliding valves do not maintain against the inter-
nal vacuum anything like tight joints, and indeed
it is impossible that they should. The leather
leaves of the motor units crack and leak. The
transmission gums up, clogs, drags and wears at
the gears.
The Gulbransen Engine
One of the finest examples of good motor con-
struction was the Gulbransen engine motor. This
was built of metal in the form of a three-cylinder
double-acting marine engine, with pistons, pistor.
rods and a highly effective rocking-valve gear
The consumption of power certainly did not ex-
ceed one-half the consumption of the wooden
bellows engine. The control was perfect and
the power very great. The latest of these en-
gines was built with a single rotary valve, which
made the timing perfect and was even more eco-
nomical than the original type. We have always
believed that this motor, though it was finally
abandoned, was the most economical and power-
ful ever designed. It certainly excelled as an
engineering work and was undoubtedly sound in
principle.
Without a doubt there ought to be a recon-
sideration of the motor in respect of its general
design. It is absurd that the mere task of turn-
ing the music roll should absorb one-half or
more of the total power-producing capacities of
the bellows. And if this fact were more generally
realized there would soon be an improvement, or
at least an attempt to produce something better.
That something better can be produced we
have no manner of doubt. The Gulbransen motor
was more costly, of course, than one made in the
(Continued
on pa
is an accomplished fact with
Pratt Read
Player Actions
Our factory is running full force and full
time, producing and shipping more player
actions than at any time prior to the
Armistice.
, .
Over 60 piano manufacturers install them.
The Pratt Read Player Action Co.
Main Office and Factory, Deep River, Conn.
Foreign Office, 21, Mincing Lane, London.
'
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