Music Trade Review
Issue: 1918 Vol. 66 N. 8 - Page 9
Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
FEBRUARY 23,
THE MUSIC TRADE REVIEW
1918
9
The Tendency Now Being Shown Towards the Manufacture of High Tension
Player-Pianos Is an Excellent One, and One Which Will Eventually Result
in Many Refinements and Improvements in the Art of Player Making
When one first begins to have some under-
standing of the principle which underlies the
pneumatic action of the player-piano one is
immediately struck with the extremely moderate
nature, as one may call it, of the power-require-
ments. Those who are familiar with what is
called vacuum machinery, as used in sugar re-
fining, in postal tube work, in electric lamp
making and in similar lines, are accustomed to
deal with reductions of internal air-pressure
registering up to 200 inches water column, and
more. But the player mechanism, as now in-
variably constructed, is decidedly a low tension
machine. In other words, the effective power
which is made available by reducing the pres-
sure of internally contained air below that of
the externally pressing atmosphere can scarcely
ever be made to exceed a net difference of two
pounds to the square inch, and is usually main-
tained at about eight ounces per square inch.
The wind-motor, so-called, which runs the music
roll, is usually adjusted to run on about two
ounces per square inch; and the other non-
speaking pneumatics on a little more. Practice
differs more or less and therefore exact figures
cannot be given; but the above are correct for
all practical purposes.
High Tension
The question of changing the basis of pneu-
matic player mechanism from this low tension
to one considerably higher has often been dis-
cussed in a tentative manner. Some investiga-
tion of the facts is worth while because it is
becoming plain the modern demands for ac-
curacy of construction, responsiveness of action,
lightness of operation, etc., must bring about a
change sooner or later in some of the construc-
tional methods now deemed quite efficient.
Fundamentals
The pneumatic power of the player mechanism
is exercised upon eighty-eight sections of the
piano action, each of which requires a pressure
(total) of about two and one-half ounces to trip
it and produce an effective hammer-contact with
the sound-element or string. It is obvious that
any pressure in excess of this amount will pro-
duce tone, and that the strength of tone will be
proportional to the pressure upon the moving
walls of the operating pneumatics which con-
tact the piano action. Now, since air pressure
is, of course, uniform over all parts of a sur-
face, it is plain that the total amount of power
delivered at the action point of the piano de-
pends upon two factors, (1) the actual mathe-
matical difference between the atmospheric
pressure and the internal contained pressure,
and (2) the dimensions of the pneumatics them-
selves. A larger pneumatic operating on a lower
pressure may give as much aggregate pressure
upon the piano action as a smaller pneumatic
operating on higher pressure; and vice versa.
Obsolete Methods
Now, in the early days of the player mecha-
nism, when the only precedents for any design
were those which the reed-organ furnished, the
rule was large parts, low pressure, slow move-
ment of air from place to place, and slow change
of tone power from note to note. The reason
of all this, of course, was that the art of build-
SCHENCKE
PIANO AND
PLAYER-PIANOS
Built to a Standard and not to a Price
SCHENCKE PIANO CO., 245-249 E. 137th St., N.Y.
ing virtually leakless valves, chests and chan-
nels was not yet perfected. Innumerable ex-
periments had to be made with leathers, woods,
shellac, rubber, metal and other materials be-
fore it became possible to produce a tight pneu-
matic stack and bellows. By the time, however,
that this had been accomplished, certain ideas
as to design had become quite (irmly fixed in
the approbation of the practical makers, with
the result that many methods of construction,
originally adopted because their designers knew
no better, were continued long after their use-
fulness had ceased. Moreover, unfortunately,
certain methods of construction had been ad-
vertised to the trade, and even to the public,
to a certain extent, in the early days of the in-
dustry when competition was very sharp and
technical ignorance universal. To these, some
manufacturers became, in a sense, deeply com-
mitted, so that they could, and can, find no de-
cent excuse for discarding them even now when
their inferiority to others equally available and
less expensive is manifest.
The New Tendency
Nevertheless, it is perfectly obvious that the
whole tendency of design is towards higher
tension and consequently smaller parts. The
mechanical advantages of a pneumatic stack, for
instance, in which the pneumatics might be ar-
ranged in a single rank just as are the corre-
sponding action sections of the piano, are so
enormous that they need no description here.
But can pneumatics be made small enough with-
out sacrifice of power?
In order to answer this last question we must,
of course, discover first whether the power
plant which forms part of the player mechanism
can be adapted for any higher tension system.
Now, the present form of bellows, admirably
adapted as it is for its present low tCMision
purposes, is not designed for the rapid move-
ment of air. It is an admirable machine for
displacing slowly large quantities of air; but
it is not able to displace air rapidly. For the
latter purpose a rotary vacuum blower of some
sort is almost essential.
For it is evident that if we are to work on a
higher tension, the problem will be to move air
in small quantities, but at high speed, so as to
obtain and maintain a lower internal pressure.
This will permit of proportionately smaller
valves and pneumatics, but it will also require
more perfect tightness and a more rapid work-
ing power system or bellows set.
Power Drive
It is hard to see how the present reciprocat-
ing bellows can be adapted to give the neces-
sary results. The slow motion of the pumpers
cannot be overcome by the expedient of mak-
ing them proportionately smaller and lighter, for
the feet cannot move them with any comfort
much more quickly than at present is required
with the ordinary bellows. But seeing that the
tendency to-day is all towards the reproducing
piano with its power-driven vacuum system, one
cannot see why the step should not be taken
of producing a small vacuum rotary blower set,
with electric motor, in place of the present foot-
driven bellows. Such a set can be designed
immediately by any manufacturer of electric
pumping machinery, once the figures are given
him showing both the maximum requirements
and the average displacement on average load.
It may be placed at any distance from the
piano, thus clearing the lower deck of encum-
brances, and the place of the ordinary foot-con-
trol can be taken by a system just as easy to
operate, making use of the well-known pedal
movements common to the usual type of player,
and in fact, differing only in being much lighter
and more nearly effortless.
It is not necessary in this place to go into
any detail with regard to the operation of ex-
pression governors to take the place of the or-
dinary variable foot-pressure on pumper bel-
lows, when power blowing is being used. The
methods are perfectly simple, requiring no more
than a connection between each foot pedal and
the corresponding governor for each half of the
divided action. The connection may be a di-
rect pull on the moving walls of the governor,
a pull upon a moving slide-valve or a pull upon
tension springs.
But, aside from this incidental point, the use
of high tension with power blowing will, of
course, have various other modificatory effects.
The pneumatic and valves will, of course, be
smaller proportionately with the increase of ten-
sion. Generally speaking, the blow power need
not exceed ten pounds upon a piano key at the
very maximum, nor does a pianist, hitting with
all his might, get a louder tone or anything else
from the use of more force than this. But
suppose we were using a steady working pres-
sure of, say, only two pounds per square inch
at the blower. Then a pneumatic of five square
inches could deliver a ten-pound blow. If we
were using a normal working pressure of live
pounds the pneumatic need only have two square
inches of surface, and some such dimension,
as these would be probably ideal for our prr
poses, permitting the use of pneumatics snail
enough to stand in a single row or bank agai.s.
the piano action.
Duplex Pressure
There is another point. With a five-p nr.d
pressure, reducible at will, it would be possible
to use a valve operating on the maximum pres
sure, but bleeding out the air from the pneu-
matic into a chest maintained on any pressure
less than this, as determined by the exp-iv.s'on
governor. No such possibility exists n or-
dinarily foot-driven players, which are buiit to
work upwards from zero. But with tliL- maxi-
mum power constantly operating, this great ad-
vantage of a valve working under hig'.i pres-
sure constantly, with a pneumatic work ng on
controllable pressure, becomes possible.
It
would be necessary, on a high tension player
such as we are describing, to use two valves,
simply so that the external pressure on the mov-
ing paper roll might not be so great as to fo*re
leakage through the paper or interfere with t e
legitimate operation of the roll.
Advantages
These few ideas are put forth in order to clear
the ground for a later and more thorough in-
vestigation of the technical questions involved.
It need only be said in conclusion that the ad-
vantages to be gained by the adoption of high
tension are much greater than mere refinement
of design. They involve a whole new vista of
possibilities, smaller size of action, quicker re-
sponse, better control, more musical results.
They apply to every type of pneumatic action,
from the player-piano of commerce to the most
expensive and elaborate grand reproducing
piano. Already there is a tendency to work to-
wards the high tension ideal; a tendency ap-
parently irresistible.
The Kimball Piano House, of Marysville,
Cal., is preparing to move to a new location on
D street.
FEBRUARY 23,
THE MUSIC TRADE REVIEW
1918
9
The Tendency Now Being Shown Towards the Manufacture of High Tension
Player-Pianos Is an Excellent One, and One Which Will Eventually Result
in Many Refinements and Improvements in the Art of Player Making
When one first begins to have some under-
standing of the principle which underlies the
pneumatic action of the player-piano one is
immediately struck with the extremely moderate
nature, as one may call it, of the power-require-
ments. Those who are familiar with what is
called vacuum machinery, as used in sugar re-
fining, in postal tube work, in electric lamp
making and in similar lines, are accustomed to
deal with reductions of internal air-pressure
registering up to 200 inches water column, and
more. But the player mechanism, as now in-
variably constructed, is decidedly a low tension
machine. In other words, the effective power
which is made available by reducing the pres-
sure of internally contained air below that of
the externally pressing atmosphere can scarcely
ever be made to exceed a net difference of two
pounds to the square inch, and is usually main-
tained at about eight ounces per square inch.
The wind-motor, so-called, which runs the music
roll, is usually adjusted to run on about two
ounces per square inch; and the other non-
speaking pneumatics on a little more. Practice
differs more or less and therefore exact figures
cannot be given; but the above are correct for
all practical purposes.
High Tension
The question of changing the basis of pneu-
matic player mechanism from this low tension
to one considerably higher has often been dis-
cussed in a tentative manner. Some investiga-
tion of the facts is worth while because it is
becoming plain the modern demands for ac-
curacy of construction, responsiveness of action,
lightness of operation, etc., must bring about a
change sooner or later in some of the construc-
tional methods now deemed quite efficient.
Fundamentals
The pneumatic power of the player mechanism
is exercised upon eighty-eight sections of the
piano action, each of which requires a pressure
(total) of about two and one-half ounces to trip
it and produce an effective hammer-contact with
the sound-element or string. It is obvious that
any pressure in excess of this amount will pro-
duce tone, and that the strength of tone will be
proportional to the pressure upon the moving
walls of the operating pneumatics which con-
tact the piano action. Now, since air pressure
is, of course, uniform over all parts of a sur-
face, it is plain that the total amount of power
delivered at the action point of the piano de-
pends upon two factors, (1) the actual mathe-
matical difference between the atmospheric
pressure and the internal contained pressure,
and (2) the dimensions of the pneumatics them-
selves. A larger pneumatic operating on a lower
pressure may give as much aggregate pressure
upon the piano action as a smaller pneumatic
operating on higher pressure; and vice versa.
Obsolete Methods
Now, in the early days of the player mecha-
nism, when the only precedents for any design
were those which the reed-organ furnished, the
rule was large parts, low pressure, slow move-
ment of air from place to place, and slow change
of tone power from note to note. The reason
of all this, of course, was that the art of build-
SCHENCKE
PIANO AND
PLAYER-PIANOS
Built to a Standard and not to a Price
SCHENCKE PIANO CO., 245-249 E. 137th St., N.Y.
ing virtually leakless valves, chests and chan-
nels was not yet perfected. Innumerable ex-
periments had to be made with leathers, woods,
shellac, rubber, metal and other materials be-
fore it became possible to produce a tight pneu-
matic stack and bellows. By the time, however,
that this had been accomplished, certain ideas
as to design had become quite (irmly fixed in
the approbation of the practical makers, with
the result that many methods of construction,
originally adopted because their designers knew
no better, were continued long after their use-
fulness had ceased. Moreover, unfortunately,
certain methods of construction had been ad-
vertised to the trade, and even to the public,
to a certain extent, in the early days of the in-
dustry when competition was very sharp and
technical ignorance universal. To these, some
manufacturers became, in a sense, deeply com-
mitted, so that they could, and can, find no de-
cent excuse for discarding them even now when
their inferiority to others equally available and
less expensive is manifest.
The New Tendency
Nevertheless, it is perfectly obvious that the
whole tendency of design is towards higher
tension and consequently smaller parts. The
mechanical advantages of a pneumatic stack, for
instance, in which the pneumatics might be ar-
ranged in a single rank just as are the corre-
sponding action sections of the piano, are so
enormous that they need no description here.
But can pneumatics be made small enough with-
out sacrifice of power?
In order to answer this last question we must,
of course, discover first whether the power
plant which forms part of the player mechanism
can be adapted for any higher tension system.
Now, the present form of bellows, admirably
adapted as it is for its present low tCMision
purposes, is not designed for the rapid move-
ment of air. It is an admirable machine for
displacing slowly large quantities of air; but
it is not able to displace air rapidly. For the
latter purpose a rotary vacuum blower of some
sort is almost essential.
For it is evident that if we are to work on a
higher tension, the problem will be to move air
in small quantities, but at high speed, so as to
obtain and maintain a lower internal pressure.
This will permit of proportionately smaller
valves and pneumatics, but it will also require
more perfect tightness and a more rapid work-
ing power system or bellows set.
Power Drive
It is hard to see how the present reciprocat-
ing bellows can be adapted to give the neces-
sary results. The slow motion of the pumpers
cannot be overcome by the expedient of mak-
ing them proportionately smaller and lighter, for
the feet cannot move them with any comfort
much more quickly than at present is required
with the ordinary bellows. But seeing that the
tendency to-day is all towards the reproducing
piano with its power-driven vacuum system, one
cannot see why the step should not be taken
of producing a small vacuum rotary blower set,
with electric motor, in place of the present foot-
driven bellows. Such a set can be designed
immediately by any manufacturer of electric
pumping machinery, once the figures are given
him showing both the maximum requirements
and the average displacement on average load.
It may be placed at any distance from the
piano, thus clearing the lower deck of encum-
brances, and the place of the ordinary foot-con-
trol can be taken by a system just as easy to
operate, making use of the well-known pedal
movements common to the usual type of player,
and in fact, differing only in being much lighter
and more nearly effortless.
It is not necessary in this place to go into
any detail with regard to the operation of ex-
pression governors to take the place of the or-
dinary variable foot-pressure on pumper bel-
lows, when power blowing is being used. The
methods are perfectly simple, requiring no more
than a connection between each foot pedal and
the corresponding governor for each half of the
divided action. The connection may be a di-
rect pull on the moving walls of the governor,
a pull upon a moving slide-valve or a pull upon
tension springs.
But, aside from this incidental point, the use
of high tension with power blowing will, of
course, have various other modificatory effects.
The pneumatic and valves will, of course, be
smaller proportionately with the increase of ten-
sion. Generally speaking, the blow power need
not exceed ten pounds upon a piano key at the
very maximum, nor does a pianist, hitting with
all his might, get a louder tone or anything else
from the use of more force than this. But
suppose we were using a steady working pres-
sure of, say, only two pounds per square inch
at the blower. Then a pneumatic of five square
inches could deliver a ten-pound blow. If we
were using a normal working pressure of live
pounds the pneumatic need only have two square
inches of surface, and some such dimension,
as these would be probably ideal for our prr
poses, permitting the use of pneumatics snail
enough to stand in a single row or bank agai.s.
the piano action.
Duplex Pressure
There is another point. With a five-p nr.d
pressure, reducible at will, it would be possible
to use a valve operating on the maximum pres
sure, but bleeding out the air from the pneu-
matic into a chest maintained on any pressure
less than this, as determined by the exp-iv.s'on
governor. No such possibility exists n or-
dinarily foot-driven players, which are buiit to
work upwards from zero. But with tliL- maxi-
mum power constantly operating, this great ad-
vantage of a valve working under hig'.i pres-
sure constantly, with a pneumatic work ng on
controllable pressure, becomes possible.
It
would be necessary, on a high tension player
such as we are describing, to use two valves,
simply so that the external pressure on the mov-
ing paper roll might not be so great as to fo*re
leakage through the paper or interfere with t e
legitimate operation of the roll.
Advantages
These few ideas are put forth in order to clear
the ground for a later and more thorough in-
vestigation of the technical questions involved.
It need only be said in conclusion that the ad-
vantages to be gained by the adoption of high
tension are much greater than mere refinement
of design. They involve a whole new vista of
possibilities, smaller size of action, quicker re-
sponse, better control, more musical results.
They apply to every type of pneumatic action,
from the player-piano of commerce to the most
expensive and elaborate grand reproducing
piano. Already there is a tendency to work to-
wards the high tension ideal; a tendency ap-
parently irresistible.
The Kimball Piano House, of Marysville,
Cal., is preparing to move to a new location on
D street.
Future scanning projects are planned by the International Arcade Museum Library (IAML).