Improvements in Pneumatically Operated Automatic Musical Instruments.
Year: 1899

page_text: Date of Application, 1st Mar., 1899
Complete Specification Left, 24th Oct., 1899-Accepted, 25th Nov., 1899
PROVISIONAL SPECIFICATION.
Improvements in Pneumatically Operated Automatic Musical
Instruments.
I, CHARLES BIGELOW KENDALL, of 53, State Street, Boston, Massachusetts,
United States of America, Broker, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to pneumatically operated musical instruments,
particularly those of the kind referred to in the Specification of my prior Patent
No. 15696 of 1897.
In my aforesaid prior specification I described, for the purpose of operating the
devices employed for actuating the fret-stops and the pickers for plucking the
strings, a pneumatic box divided into compartments or valve chambers provided
with valves which were controlled by what I termed "primary actuators in the
form of small bellows. These primary actuators were situated within an exhaust
compartment or chest in said pneumatic box, which chest was common to all of
the valve chambers and was kept in a vacuous condition by means of bellows
operated by suitable mechanism. The aforesaid primary actuators were connected
by pipes with a "tracker bar" past which a perforated music sheet was caused to
travel. As the perforations in such sheet came opposite one or more of the openings
in the tracker bar the external atmosphere was allowed to enter the respective
primary actuators and cause one or other of the respective valves to be lifted,
whereby one or more of the valve chambers were put into connection with the
exhaust chest and the devices for actuating the fret stops and the pickers thus
pneumatically operated.
The chief object of my present invention is to improve the construction of the
aforesaid pneumatic box.
According to this invention I substitute for the aforesaid box a series of
sectional pieces which when combined together constitute the equivalent of the
said box. The lower portion of each section is formed with cavities or chambers
which communicate by pipes with the openings in the tracker bar and above each
of the said cavities or chambers I arrange a flexible diaphragm. Each of these
diaphragms is furnished with a stem of wood or other appropriate material which
projects into a valve chamber located above said stem. The upper part of said
valve chamber is formed with openings one of which communicates with the
atmosphere and is capable of being closed by a spherical valve in said valve
chamber when the aforesaid stem is lifted, while the other opening communicates
with one of the series of actuators controlling the fret stops and the pickers. The
aforesaid stems extend through an exhaust chamber which is located above the
diaphragms and which is in communication with the exhaust bellows. Therefore
when the perforated music sheet in its passage past the tracker bar permits air
to enter below one or other of the diaphragms, the latter will be lifted and the
stem caused to bring the spherical valve into a position to close the opening in
the valve chamber leading to the atmosphere and to open to the vacuum chamber,
the passage communicating with the fret-stop and picker actuators, whereby the

page_text: latter will be pneumatically operated as explained in the specification of my
aforesaid prior patent.
Between the diaphragms and the cavities or chambers in the lower portion of the
sectional pieces, I provide a dust chamber for collecting the dust that might other-
wise reach an air vent with which each of the diaphragms is provided. The area
of the dust chambers with relation to the tubes leading from the tracker bar,
should be such that the air in entering said dust chambers will be free to expand
sufficiently to liberate any dust particles which it may contain, and yet not expand
so much as to be incapable of effectually operating the said diaphragms. If
desired a screen may be applied to each of the dust chambers to more effectually
collect the dust and such screen may be in the form of a gauze partition.
Each of the aforesaid sectional pieces is composed of separable parts, which, for
convenience of detachment are connected together by means of clips or clamps.
These clips or clamps may be in the form of spring strips suitably bent at their
ends to grip the bottom and top parts of the sectional pieces. Screws or similar
devices for attaching the parts together are thereby dispensed with. The aforesaid
sectional pieces may be connected together in the apparatus by means of adjustable
end clamps or in any other suitable manner.
I wish it to be understood that although I have herein more particularly referred
to my improvements in connection with devices for playing a stringed musical
instrument, such improvements are equally applicable to any other kind of musical
instrument that is adapted to be played by pneumatic mechanism under the control
of a moving perforated music sheet.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in Pneumatically Operated Automatic Musical
Instruments.
I, CHARLES BIGELOW KENDALL, of 53, State Street, Boston, Massachusetts,
United States of America, Broker, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention,has reference to pneumatically operated musical instruments,
particularly those of the kind referred to in the Specification of my prior Patent
No. 15696 of 1897.
In my aforesaid prior specification I described, for the purpose of operating the
devices employed for actuating the fret-stops and the pickers for plucking the
strings, a pneumatic box divided into compartments or valve chambers provided
with valves which were controlled by what I termed "primary actuators" in the
form of small bellows. These primary actuators were situated within an exhaust
compartment or chest in said pneumatic box, which chest was common to all of
the valve chambers and was kept in a vacuous condition by means of bellows
operated by suitable mechanism. The aforesaid primary actuators were connected
by pipes with a "tracker bar" past which a perforated music sheet was caused to
travel. As the perforations in such sheet came opposite one or more of the openings
in the tracker bar the external atmosphere was allowed to enter the respective

page_text: primary actuators and cause one or other of the respective valves to be lifted,
whereby one or more of the valve chambers were put into connection with the
exhaust chest and the devices for actuating the fret stops and the pickers thus
pneumatically operated.
The chief object of my present invention is to improve the construction of the
aforesaid pneumatic box.
According to this invention I substitute for the aforesaid box a series of separable
sectional casings or actions which when connected together in the apparatus by
means of adjustable end clamps or in any other convenient manner constitute the
equivalent of the said box.
Each of the aforesaid sectional casings or actions is composed of separable paris
or sub-sections, which, for convenience of detachment are connected together by
means of clips or clamps.
The lowest sub-section or dust chest of each sectional casing is provided with
cavities or chambers which communicate with the openings in the tracker bar.
Each of these chambers provided with a transverse dust screen, and the part of
the chamber above the dust screen is enlarged.
The next sub-section or diaphragm chest is provided with flexible diaphragms
an communication with the chambers in the lowest sub-section.
The next sub-section or exhaust valve chest carries spherical valves adapted to
be operated by the said flexible diaphragms, and is provided with valve ports
communicating with an exhaust chamber formed immediately above the
diaphragms.
The top sub-section comprises the valve chest cover which is provided with valve
ports connecting the valve chamber to the external atmosphere, and also with
ports communicating with a bellows motor for operating the musical instrument.
The exhaust chest is common to all the actions.
These sectional casings or actions are separable or sectional in a double sense,―
that is to say, each complete sectional casing is separable as a whole from the
series of sectional casings having a common exhaust chest, and the sub-sections
of each sectional casing may be readily taken apart and all their interior portions
examined, repaired or adjusted, if necessary.
In order that my invention may be clearly understood and readily carried into
effect I will proceed to describe the same more fully with reference to the accom-
panying drawings in which;
Figure 1 is a plan view, and Figure 2 a side view of a series of these sectional
casings or actions arranged side by side. Figure 3 is an end view on a reduced
scale showing a series of the actions in their relation to the tracker bar, music
sheet, and bellows motors ordinarily employed in instruments of this class.
Figure 4 is a plan view, and Figure 5 is a side view, of one of these complete
sectional casings, shown separately. Figure 6 is a side view, in section taken on
the line 6-6 of Figure 4, showing the interior construction and arrangement
of the sectional casing. Figure 7 is an edge view of the sectional casing shewn in
Figures 4 and 5. Figure 8 is an edge view in section, taken on the line S-8
of Figure 6. Figure 9 is an end view, and Figure 10 a side view, partly in section,
of the valve chamber cover: Figure 11 is a plan view and Figure 12 a side view,
partly in section, of the valve chamber and exhaust chest sub-section; Figure 1
is a plan view, and Figure 14 a side view, partly in section, of the diaphragm
sub-section and Figure 15 is a plan view, and Figure 16 a side view, partly in
section, of the dust chamber sub-section of one of the sectional casings.
S S are the separable sectional casings each of which comprises a valve chest
cover 20, an exhaust valve chest 21, a diaphragm chest 22, and a dust chest 23.
These chests are made of uniform width, in order that the joints between the
sections may be air tight when they are assembled and clamped together in series
for operation. Packing strips 24 are preferably placed between the sectional
casings which, when firmly compressed between the clamping pieces 25 and 26,
are thereby rendered as nearly air-tight as possible, the strips 24 being provided

page_text: with an aperture coincident and coextensive with the exhaust chamber 44, so as
to make that chamber extend through and be common to all the actions of the
assembled series.
Each action is, provided with an inlet tube 27, which extends from its base 23
to the tracker bar 28, across which latter the music sheet 29 is drawn by winding
it from the roller 30 to the roller 31, or rice versa, as best shown in Figure 3.
Each action is also provided with a tube 32, which extends from an opening in
the cover 20, and affords communication between the valve chamber 33 and the
bellows motor 34. The bellows 34 is held in its open position during the inter-
mission in its operation, by means of the spring 36 as shown in Figure 3. This
arrangement and relation of the pneumatic actions to the controlling music sheet,
and to the motor, shown in Figure 3, is of the customary kind, and therefore need
not be more particularly described.
The separable sectional casings are herein shown each to contain two complete
and independent pneumatic actions, which are exactly alike in all respects, and it
is obvious that each said sectional casing may be made wide enough to contain aný
desired number of these actions.
Each of the valve chest covers 20 is provided with air ducts 40, which ducts lead
to the external atmosphere, and if desired, are covered by the gauze netting 41,
to keep out the dust. The exhaust valve chest 21 is provided with the valve
chambers 33, from which the ducts 43 lead to the exhaust chamber 44, which latter
is common to all of the actions contained in the series and in fact, when these
sectional casings are assembled in series, the exhaust chamber 44 being open
entirely through each sectional casing as shown in Figure 5, forms a continuous
exhaust chest common to all of the pneumatic actions in the assembled series.
The ducts 43 are located immediately below the similar ducts 40 in the cover, and
the valve 46, which is spherical in form, is located between these two ducts. The
ends of the ducts are preferably faced with washers 42 and 45 of paper, leather,
or similar substance, to form air-tight seats for the valve. The height of the
valve chamber 33, and the consequent separation of the valve seats 42 and 45,
is only sufficient to allow either duct to be opened to the desired extent when
the valve is resting against the seat of the opposite duct, as best shown in Figures 6
and S. The distance between the faces of the valve seats may be varied to alter
the duct opening, but in all cases such distance is less than the diameter of the
valve, so as to retain the latter in place. This arrangement serves also to centralize
the valve with each of its seats, and causes it when in operation to reciprocate
between its two positions shown in Figure 6, in a direct line. Therefore, as the
required movement is very short, the valve may be operated with great rapidity
and certainty of action.
Under the influence of its own weight, and of the partial vacuum in the exhaust
chest 44, the spherical valve 46 rests during the intermissions in its movement
upon its lower seat 45, closing the duct 43, leading to the exhaust chamber 44,
and opening the duct 40 to the external atmosphere. Each valve is operated,
under the control of its corresponding aperture in the music sheet, by means of
the valve pin 47, the lower end of which is centered and supported by a vibrating
pneumatic diaphragm 48, which is attached to the upper surface of the diaphragm
chest. 22, and covers the diaphragm chamber 49 located immediately beneath and
in line with the ducts 40 and 43, the diaphragm being cupped or fulled so as to
be capable of vertical movement at its centre, (represented by comparison of the
positions of the actions shown in Figure 6), sufficient to raise the valve 46 from
the lower duct 43, to close the upper duct 40. The diaphragms are each provided
with a small vent aperture 50 (Figure 3) through which is exhausted the air that
remains in the space below the diaphragm after the passage of a music sheet per-
foration over the corresponding hole in the tracker bar; so that during the
intervals between the passage of the successive perforations of the music sheet over
the tracker bar aperture, the vacuum existing in the exhaust chest 44 is extended
to the music sheet, thereby enabling the action to respond with the utmost

page_text: promptness upon the admission of air through the succeeding perforation in the
music sheet.
Each of the inlet tubes 27, extending from the tracker bar to the actions, enters
a dust chamber 51 in the dust chest 23. This dust chamber has a cross sectional
area greater than that of the interior of the inlet tubes 27, so that the air upon
entering the dust chamber is expanded. This expansion of the air has a tendency
to liberate the particles of dust which may have entered the dust chamber 51
with the blast of air, thereby permitting such particles to settle down to the
bottom of the chamber, out of the principal air current, which latter passes upward
toward and against the diaphragm 48. The lower ends of the dust chambers 51
are closed by means of the plugs 52, through which the tubes 27 pass. These
plugs are preferably of rubber or other compressible material, and are made
tapering, so as to make an air-tight closure for the dust chamber and around the
outside of the tube. The discharging ends of the tubes are also preferably turned
to one side, as shown in Figures 6 and 16, so as to discharge directly against the
side of the dust chamber 51. This serves to deflect the air and its contained dust
and thereby assists in separating the latter and allowing it to settle down to the
bottom of the dust chamber.
The upper end of the dust chamber 51 is preferably covered by a porous
diaphragm 53, formed of a piece of gauze netting which is most conveniently sup-
ported upon a shoulder formed by the enlarged chamber or counterbore 54. This
enlarged counterbore is preferably made of a diameter and location coincident
with the diaphragm chamber 49. This enlargement of the chambers 49 and 54
permits of a further expansion of the incoming air as it passes from the chamber 51
through the porous diaphragm 53, which further expansion serves to liberate and
arrest from the said air, the dust that may have reached this point.
The operative effect of the air upon the diaphragm 48 is not materially
diminished by the reduction of its pressure due to the aforesaid expansion, inas-
much as the area of the diaphragm, upon which the reduced pressure is exerted,
is obviously increased in a ratio corresponding to that of the reduction of pressure.
The diaphragm chest 22 and the dust chest 23 are preferably made in separate
parts, as herein shown, in order to afford ready access to the gauze netting 53,
and to the under side of the diaphragm 48. The joint between these chests is
packed by means of the strip 38, so as to prevent leakage of air when the actions
are in use, the pressure of the clamps 56 being sufficient for this purpose.
When the perforated music sheet, in its passage past the tracker bar, permits
air to enter below one or other of the diaphragms, the latter will be lifted and
a stem 47 caused to bring the spherical valve into position to close the opening in
the valve chamber leading to the atmosphere, and to open to the vacuum chamber,
the passage communicating with the bellows 34 whereby the musical instrument
will be pneumatically operated as explained in the specification of my aforesaid
prior patent.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. A sectional casing for pneumatic sections, comprising a separable cover for
the valve chamber, and detachable means for clamping the cover to place.
2. A sectional casing for pneumatic actions, comprising a separable valve chest
containing an exhaust chamber and a valve chamber therefor, with detachable
means for clamping the valve chest in place.
3. A sectional casing for pneumatic actions, comprising a separable diaphragm
chest, and means for clamping it in place.
4. A sectional casing for pneumatic actions, comprising a separable dust collect-
ing chamber, and means for clamping it in place.
5. A sectional casing for pneumatic actions consisting of separable sub-sections
comprising an exhaust valve chest, a cover therefor, a diaphragm chest, a cover

page_text: therefor, and a dust chest, with a detachable means for clamping the sub-sections
together in operative relation.
6. In a pneumatic action, in combination with the air inlet, an enlarged
expanding chamber for separating and collecting the dust.
7. In a pneumatic action, in combination with the primary pneumatic and the
air inlet, an enlarged dust collecting chamber between the air inlet and the
primary pneumatic.
8. In combination with a pneumatic action, an air inlet therefor, a diaphragm
chamber, and an intermediate enlarged dust collecting chamber.
9. In a pneumatic action, the combination of a spherical valve, and two oppo-
sitely disposed ducts having circular valve seats whereby the valve is centered and
retained in place.
10. In a pneumatic action, the combination of a spherical valve, a chest and a
removable cover therefor provided with oppositely disposed ducts having circular
seats for the valve, for the purpose of centering and retaining the valve in operative
position.
11. In a pneumatic action, the combination of a valve, a chest therefor provided
with oppositely disposed ducts having circular valve seats, a vibrating pneumatic
diaphragm for moving the valve from one seat to the other, an air inlet leading
to the diaphragm, and means for controlling the admission of air to the diaphragin
12. In a pneumatic action, in combination with the air inlet thereof, an enlarged
expanding chamber, and a porous diaphragm for separating and collecting the
dust.
13. In a pneumatic action, in combination with the primary pneumatic and the
air inlet thereof, an enlarged dust collecting chamber and a porous diaphragm
between the air inlet and the primary pneumatic.
14. A pneumatic action for a musical instrument, constructed, arranged, and
operating, substantially as described with reference to the accompanying drawings
for the purpose specified.
Dated this 24th day of October 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.