IMPROVEMENTS IN MECHANICAL MUSICAL INSTRUMENTS
Year: 1884

page_text: I WILLIAM BRITAIN, Junior, of Nugent House, Lambton Road, Hornsey Rise,
London, in the County of Middlesex, Gentleman, do hereby declare the nature of
my invention for "IMPROVEMENTS IN MECHANICAL MUSICAL INSTRUMENTS
as follows:-
to be
My Invention relates to improvements in mechanical musical instruments
actuated by a perforated music sheet and it consists :-in an improved construction
of bellows, the bellows being formed on each side of a board working between two
other boards fixed at the required angle and having when required an extended
hinge to ensure its working correctly; in an improved pneumatic action obtained
by the aid of a flexible diaphragm covering a raised valve seat in connection with
suitably arranged channels from the wind chest and music sheet; in a sliding
arrangement of the reed chest for changing the key of the music played; in
arranging the rollers that press the music sheet so that, together with their frame
and springs, they may be raised upon a hinge at one end for the insertion of the
music in sheets or endless bands; in a method of producing expression by using
springs of short range upon the reservoir and causing the safety valve to come into
action in different positions of the springs, as loud or soft is required; also in an
automatic swell worked by diaphragms connected with the wind chest and music
sheet by channels.
In constructing an improved mechanical musical instrument embodying my
improvements: I proceed as follows:-
I make the bellows of a top board having an underboard fixed to it, by a block
at one end, at any required angle, and a third board working between them with
the leather and usual fittings on each side of it, thus forming a double bellows one
part of which opens as the other shuts. Where it is not possible to work the
bellows from a line through the centre of pressure I carry out an extended hinge at
the back to the correct point of support.
I use a reservoir of ordinary construction below the underboard of the bellows
and an expression safety valve hereinafter explained. I make the reed chest with
the ordinary chambers or channels and reeds, but I raise the valve holes above the
surface by means of tubes, and about level with the tops of these tubes I place a
board having holes out in it concentric with the tubes but considerably larger, and
I cover each hole with a diaphragm, of leather, skin, or any suitable material,
which I make rather baggy so that it may rise and fall as required. I form
channels running from the backs of the diaphragms to the centre of the diaphragm
board where each is met by a vertical hole or channel continued upwards through
the "port-block or wind outlet to the music.

page_text: Immediately below each vertical channel is a small hole, which I term the
"Injector," in communication with the air in the reed chest.
The perforated band or music sheet and the bellows being set in motion by the
ordinary driving gear the action of the instrument will be as follows:-
When a blank space in the music sheet is over the top of the vertical channel
the wind presses through the reed to the underside of the diaphragm and being
met by a greater pressure, on the other side, from the wind which passes through
the small hole or "injector" and along the channel at the back of the diaphragm,
the valve hole is effectually stopped. The greater pressure is due to the diaphragm
being larger than the valve-hole.
When an opening in the music sheet passes over the top of the vertical channel
the jet of air from the small hole acts like an injector and carries the air from
behind the diaphragm up the vertical channel and so opens the valve-hole and
allows the reed to speak; the action is of course assisted by the pressure below the
diaphragm.
I secure the reed-chest and diaphragm board together and so construct them that
they may slide on the top board of the bellows and be held down by the "port-
block" by means of springs pressing upon pins, and thus, the pitch of any tune
may be raised or lowered by semi-tones to suit any voice or any other instrument.
I propose to drive the music sheet by the aid of a rubber roller worked by a band
round a pulley at its end and another on the crank axle, but I may use any con-
venient arrangement. I use two rollers to press the music. sheet, one to hold it
tight on the rubber driving roller and the other to keep it tight over the "port
block," and for convenience of putting in the music I set these rollers on an
independent frame hinged at one end, whereby they may be raised while the music
is being inserted, and I may secure this frame by a catch and spring or otherwise,
when down and pressing the rollers on the music-sheet.
I have a lid on each side of the instrument to form a swell, and to each of these
lids connect a tail-piece reaching beyond the hinge of the lid, which is actuated
by a larger diaphragm with channels, a small, one leading to the wind-chest and a
larger one leading through the "port-block" to the music sheet-I use for the
reservoir springs of a short range increasing rapidly in strength as they are opened,
and I actuate the safety valve by a lever which may be in connection with the
swell by a link, so that when the swell is shut the safety valve is opened at a
position when the springs do not exert much pressure; but when the swell is open
the safety valve does not open until the reservoir is full and the springs exert their
full pressure, and by this means I obtain an expression in addition to the swell.
If desired the two may be worked separately, and the same arrangement may
be used for a suction instrument by the reverse arrangement of the springs and
valve.
The arrangement I have described is for a compression instrument with the
diaphragm after the reed (i,e, following the course of the wind) but I may use the
diaphragm before the reed-In a Suction Instrument, whether the diaphragm is
before or after the reed, I propose to divide the "port-block" by the music sheet and
to connect its top part directly with the wind chest, the under part having the
" injector "holes opening to the atmosphere. I may in some cases substitute for
the "Injector," a small hole placed in the centre of the diaphragm so that the
wind leaking through it is only what has passed the reed, whereby there is no
waste.

page_text: I, WILLIAM BRITAIN Junior of Nugent House Lambton Rd Hornsey Rise
Middlesex, do hereby declare the nature of my invention for IMPROVEMENTS IN
MECHANICAL INSTRUMENTS and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention relates to improvements in that class of instruments known as
mechanical reed organs actuated by a perforated music sheet or paper.
In the accompanying drawings Fig. 1. is a vertical section through all the
principal parts of an instrument. Fig. 2. is an elevation of the pressing rollers and
their frame and Figs 3, 4, 5, and 6, are modifications of the pneumatic valve
action.
The letters refer to the same parts in each drawing.
I make the outer case a a support the main base board b, to which I fix at a
suitable angle another board b' forming the top board of the reservoir. Between
these two boards I make another one 6' to work, having the bellows constructed on
each side of it;-between it and the main board b at the top, and. between it and
the board 61 underneath; so that when one bellows is open the other is shut. The
centre board. 6' I work by links and cranks in the usual way. Where it is
impossible to attach the links in a line across the centre of preasure, I carry &
support from the back of the board 62 to its centre of action. so that it oscilates.
about that point. I make the inlet valve holes c through the board b outside the
air-chamber, and the outlet valve holes c through the board b inside the air-
chamber; in the same way the inlet valves c for the underneath bellows are
outside the reservoir, and the outlet valves are inside the reservoir. The. drawing.
shows two such pairs of bellows. I connect the air-chamber, with the reservoir by
the way c
I make the air-chamber d in the ordinary way, with the reeds and the reed
cells d' but with, the valve seats d³ raised a little above the surface, to give free
passage for the air.
Over the valve holes, and raised slightly above them I fix a board e with holes, e¹
sunk in it concentric with, but larger that the valve holes, I cover, these holes with
diaphragms of leather or other suitable material e and connect them with the
music-sheet through the port-block f by the channels and e' and with the air
chamber by a much smaller channel e³.
The action then is as follows:-
When a blank place in the music-sheet is over the channel e the air passes,
through the hole es and along the channel e¹ to the back of the diaphragm e: at the
same time it passes through the reed to the face of, the diaphragm, but, the preasure
of the air being, equal on each side, and the back being larger than the face, or
valve seat, the valve is closed. Then when a hole in the music-sheet opens the top
end of the channel e the wind blowing through the small hole e and up the
channel, acts like an injector and carries the air from behind the diaphragm out
with it, and so opens the valve, the preasure under the valve of course assisting.
This description applies to a preasure instrument with the valve after the reed
(that is, in the direction of the wind,) but Fig. 3 shows part of a preasure
instrument with the valve before the reed.

page_text: Figs. 4 and 5 represents parts of suction instruments one with the valve before,
and the other with it after the reed. In these case I continue the channels e¹
above the music-sheet, and connect the upper part by the passage e with the
exhaust bellows, and the under part I connect by the passage e' with the
external air.
Fig 6 represents another modification where the hole is substituted by one
placed in the diaphragm; the action is the same.
I fix the air-chamber and diaphragm board together, and make them to slide
upon the main board b and I hold them down air-tight by the port-block fand the
springs f¹, so that they can be moved lengthwise of the port-block; changing
the respective positions of the channels e (Fig 2), and so altering the key of
the music played by semitones, without altering the outward appearance of the
instrument.
I fix the handle to the end of the cranked axle g and drive the music by the
rubber roller h through the band g¹ and wheel g³. I make two presser rollers held
down by springs ; one, i to press the music sheet upon the rubber roller h, and
the other to hold it tight over the port-block, and I connect these two togather
by a frame i working on hinges at one end, and having a catch at the other so that
they may easily be raised, as shown in Fig 2 to admit the music, either in an
endless band, or sheet.
(
I make an automatic swell or swells k k to work with diaphragms and channels
the same as the notes, so that when there is a hole in the music sheet, the air
escapes from behind the diaphragms kk and the lids close, but when there is no
hole in the music sheet the diaphragms force the tails of the lids down and
open the swell.
I make an automatic expression by fixing the pin m¹ that works the safety
valve m³, on the end of a lever m working at m³, and the other end of the lever I
connect by the link m' with the swell; so that when the swell is shut the safety
valve is opened where the spring exerts but slight preasure, but when the swell is
open the safety valve does not open until the reservoir is wide open and under full
preasure. When desirable I work the expression by a seperate diadiaphragm so that
it can work independand of the swell.
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 pneumatic action for a mechanical musical instrument consisting of a
diaphragm acting as a valve with the necessary air passages substantially as
described.
2. The the method of changing the key of the music substantially as described.
3. The bellows of an instrument consisting of a single moving board with the
bellows constructed on either side of it, substantially as described.
4. The rollers for pressing the music sheet, hinged, togather with their frame so
as to facilitate the introduction of the music-sheet substantially as described.
5. An automatic swell for a mechanical musical instrument worked with
diaphragms substantially as described.
6. An automatic expression for a mechanical musical instrument produced by the
varying preasure of the spring substantially as described.