Improvements in Phonographs and Phonograms.
Year: 1887

page_text: Date of Application, 14th Dec., 1887
Complete Specification Left, 14th Sept., 1888
Complete Specification Accepted, 19th Oct., 1888
PROVISIONAL SPECIFICATION.
Improvements in Phonographs and Phonograms.
I, GEORGE EDWARD GOURAUD, of Little Menlo, Beulah Hill, in the County of
Surrey, late Colonel in the United States Army, do hereby declare the nature
of this invention (a communication to me from abroad by Thomas Alva Edison, of
Llewellyn Park, in the County of Essex and State of New Jersey, one of the United
States of America,) to be as follows:-
The object of this invention is generally to so improve the phonograph that it
will be well adapted for use by the public and will be a convenient and efficient
machine for various uses. More especially the object is to improve the recording
and reproducing qualities of the instrument, to provide a proper motor for running
the phonogram-cylinder at a uniform speed, to provide a suitable phonogram-cylinder
and phonogram, and to arrange and construct the several parts of the machine so
that its manipulation will be simple, readily understood and convenient for the
purposes for which the machine is designed.
The frame of the machine is constructed, for convenience, of a top and bottom
plate, each constructed as a spider composed of four arms, the ends of the arms of
the two frames being joined by vertical posts. To these posts are connected the yokes
of four magnets, each projecting from the post to which it is attached towards the
adjoining post to which its pole-pieces are connected by braces of brass or other
non-magnetic metal. The poles of the four magnets project inwardly and are cut
with concave faces, the poles of all four magnets being in the line of a circle. Within
this circle, mounted upon a vertical shaft, a fly-wheel, constructed of brass and
having a heavy rim, so as to increase its weight. Upon the periphery of the rim
of the fly-wheel are secured a number of armatures of iron, which are placed vertically,
equal distances apart, and travel in their movement close to the pole-pieces of the

page_text: magnets. Upon the shaft, above the wheel, is mounted a sleeve, of insulating material,
upon which
secured a metal collar, and above this collar, a commutator; the com-
mutator being composed of a ring of metal having its surface broken by blocks of
insulating material, so that it presents alternate spaces of insulation and metal in a
manner well understood. From the collar projects an arm in a radial direction, and
upon the end of this arm is pivoted a swinging weight-arm, which, by its outward
movement, moves a lever which is held against its movement by an adjustable spring.
The lever bears normally upon an insulated contact-screw, which is connected by a
wire with the base of the commutator. The magnets have one end of their windings
connected together by a wire. The other end of the windings of two opposite
magnets are connected together by a wire; while the other ends of the windings of
the other opposite magnets are connected together by another wire. These wires are
connected with two springs which bear upon the face of the commutator. A spring
bears directly upon the collar. These three springs are supported by a circular piece
of insulation, which is supported above the fly-wheel and below the top plate by means
of posts extending down from the top plate. The motor is driven by a battery or
other source of electricity. One pole of the battery which drives the motor is con-
nected with the wire, which joins one end of the windings of all the magnets; while
the other pole of the battery is connected with the spring bearing upon the collar.
The parts are arranged so that the fly-wheel will be turned by the magnets always in
one direction. The one pair of opposite magnets first receive the current and attract
two armatures upon the wheel, and then the other pair of magnets receive the current
and attract two armatures upon the wheel, the current being transferred from one
pair of magnets to another in succession, so that the wheel is given a continuous
rotary movement. An excess of battery power is preferably used, and the speed of
the wheel controlled by the governor, formed by spring-retracted arms. This governor
opens the circuit when the speed exceeds the normal, so that, within limits of variation,
which are so small as to be practically of no effect in the operation of the machine,
the speed will be kept uniform. By the adjustment of its spring, the governor can
be made to work at any desired point. By the use of an electro-magnetic motor of
this description, namely, one composed of a heavy fly-wheel carrying armatures on its
periphery, which are attracted by magnets arranged in a circle around the fly-wheel,
a slow and uniform motion can be obtained, which is a matter of the highest
importance in the operation of the phonograph, and tends to simplify the construction,
since the complication introduced by the employment of a number of speed-reducing
wheels is avoided. Projecting from the before mentioned collar on the opposite side
to the governor is an arm carrying a weight at its end for counter-balancing the
weight of the governor, so that the wheel may be a balanced one.
The shaft upon
which the fly-wheel is mounted is stepped on a jewel at the centre of the bottom plate,
giving freedom of movement to the wheel and reducing the noise of friction to the
minimum, so as to not affect materially the operation of the phonograph. Upon the
top plate is journalled a horizontal shaft, this shaft being carried by a journal-box in
the top of an arched standard at the centre of the top plate, and at one end by a
journal-box at the end of one of the arms of the top plate. Between these bearings,
the shaft is larger than it is outside of such bearings; so that it bears against the
inner faces of the bearings by shoulders which prevent any longitudinal movement of
the shaft. The shaft projects beyond the first mentioned bearing to the opposite side
of the machine from the other bearing, but is not supported at its ends, it being free
to receive the phonogram-cylinder, which is slipped upon this shaft, preferably
removably, and held by a spring-pin taking into a hole in the end of the shaft.
This phonogram-cylinder is made hollow of brass or other suitable metal, its
heads bearing upon the shaft so as to centre the cylinder properly. The cylinder is
made slightly taper for a purpose which will be presently explained; its inner end,
that next to the bearing, being somewhat larger than its outer end. The inner end of
the phonogram-cylinder is constructed as a bevelled friction-wheel, upon which bears
a bevelled pinion of some suitable soft material. This pinion is mounted upon the
upper end of the fly-wheel shaft, which projects through the top plate into the space

page_text: between the legs of the arched standard. The pinion may be provided with an
operative face of leather, or other similar material, mounted upon a metal hub. This
metal hub is preferably constructed to slide vertically upon the fly-wheel-shaft, it
being prevented from turning thereon by a suitable key; and beneath the pinion
is a spiral spring, which forces the pinion upwardly and keeps it solidly against the
bevelled wheel on the inner end of the phonogram-cylinder, so that the wear of the
surfaces is taken up and the pinion is kept in firm contact. By the use of this
bevelled friction gearing, of which the soft-surfaced pinion is a part, the motion
is changed from the vertical shaft of the motor to the horizontal shaft of the phono-
gram-cylinder without the production of noise which would be detrimental to the
operation of the instrument. The horizontal arrangement of the motor permits a
large fly-wheel to be used, while the compactness of the instrument is maintained.
Between its bearings, the horizontal shaft is cut with an exceedingly fine screw-
thread, of the peculiar construction which will be explained further on; while outside
of the bearing, remote from the phonogram-cylinder, the shaft is provided with a
hand-wheel by which it can be held when it is desired to remove the phonogram-
cylinder from the shaft, or remove the phonogram from the phonogram-cylinder
without taking the latter off of the shaft. Parallel with the horizontal shaft, and
located in the rear of the same, is a guide-rod, mounted in suitable supports at its
ends and extending entirely across the machine. Upon this guide-rod is an accurately
fitting tube, which is of such length that it can be moved upon the rod, between the
supports at the end of the rod, a distance equal to the length of the phonogram-cylinder.
Upon the end of this tube next to the phonogram-cylinder is secured the holding arm
which carries the recorder and reproducer while at the opposite end of this tube is
the guide-arm, which engages with the lead-screw. The guide-arm is rigid and has a
hub which slips on the said tube and is secured thereto by a set-screw. This guide-
arm projects toward the horizontal shaft, terminating at its free end above the screw-
thread. The end of the arm is slotted so as to form two guide-checks, between which
plays a vertically sliding block. This block bears upon the screw-thread, and is cut
with a section of the corresponding thread. A spring extends along the top of the
arm, and is secured to the sliding block, forcing such block downwardly upon the
screw-thread, so that a rocking movement of the tube can be made within certain
limits without disengaging the block from the screw-thread. The screw-thread and
the thread upon the block are cut as fine as it is possible to make a screw-thread
having the desired wearing capacity. This screw-thread is preferably made with
about one hundred threads to the inch; and in order to make such a fine thread do
the work required of it without danger to the guide-arm being forced back, these
threads are formed like ratchet-teeth the engaging sides of the threads being straight
and the other sides bevelled, so that the danger of slipping backward is entirely
obviated. Upon the other end of the tube is secured an arm by means of a set-screw,
such arm projecting forward over the centre of the phonogram-cylinder. Upon the
upper end of this arm is pivotted a holding frame placed nearly at right angles to the
arm and made similar to the frame of spectacles with two eyes. A pivot-screw for
this frame passes through the frame at one side and centrally between the eyes; the
nut for securing the frame bearing upon the spring-washer beneath it, so that the
frame will hold itself at either limit of its throw, and will not be jarred from position.
The arm has two horns through which a set-screw passes for limiting the movement
of the holding frame and for adjusting the point at which the frame will be stopped
when swung in either direction, so as to bring its holding eyes in the correct relation
to the phonogram-cylinder. These holding eyes carry the recorder and reproducer,
the construction of which will be presently explained; and the object of the swinging
frame is to permit either the recorder or reproducer to be brought into operative
relation with the phonogram-cylinder. The eyes have fingers which project forward
and have passing through them adjusting screws which rest, as each eye is brought
into position for operation, upon a guide-rest which extends parallel to the horizontal
shaft in front of the phonogram-cylinder, and supports the holding frame at the

page_text: required elevation to bring the recorder or reproducer into accurate adjustment. The
fingers have small handles attached to them by which the swinging holding frame can
be more conveniently manipulated. Behind the guide rod there is another rest to
receive the arm carrying the holding frame when it is thrown back. This rest is
preferably more or less springy in its character, so as not to jar the parts injuriously
when the arm is thrown back upon it. Passing through the arm near the tube, is the
shank of a cutting tool, which is thrown forward by a spring on the inner side of the
arm, and is retracted by a thumb-nut on the screw-threaded end of the shank outside
of the arm. This cutter is designed to turn off the surface of the phonogram, so as to
make it true for recording, or to turn off one record and leave the surface ready for
another record. This enables one phonogram to be used over and over again for
recording and reproducing; the recorder and reproducer being brought into operative
relation with the clear surface, as the diameter of the phonogram-cylinder is decreased,
by the adjustment of the adjusting screws, the yielding guide-block permitting this to
be done. Upon the arm carrying the holding frame for the recorder and reproducer,
and above such holding frame, is secured a carrying plate, to which is connected a
tube. This tube serves as the mouth and ear-piece of the instrument; or it may have
mouth- and ear-pieces removably attached to it. The said plate
stationary and the
holding eyes are swung under it alternately, so that one tube answers both for
recording and reproducing, thus adding to the simplicity of the instrument. The
recorder is a circular plate, which fits either eye of the carrying frame; it being
provided with a rib engaging with a groove in the eye, so that it will always have the
same position in the eye. A set-screw is used for holding the plate in the eye. This
recorder-plate has an opening through it, which is brought into line with the tube
when the eye is swung into position for the operation of the recorder. The back of
the plate is recessed to form a circular chamber on a shoulder in which is placed the
diaphragm, which is preferably made of celluloid or some other light material, and is
placed in the recess at the back of the recorder-plate, but is left free at its edges. The
recording point is secured to the centre of the diaphragm by wax or in any other suit-
able way. This point is constructed of a thin plate of steel, which is cut or ground to a
point on one edge and is bevelled backwardly away from that edge so as to give a
support for the indenting point and prevent vibration of that point in operation.
This point passes through the end of a lever, and is secured therein by a set-screw;
the point being surrounded between the lever and the diaphragm by a small tube of
rubber or other suitable material. The said lever is rigid in its construction and is
mounted upon a cross-pin of considerable length, which is journalled at its ends, at
the sides of the recorder-plate. The said lever extends beyond such pivot-pin, and
rests at its outer end against a block, which is faced with a piece of pure india-
rubber. The block is set in a recess in the edge of the recorder-plate, and is adjusted
forward by a screw. This adjustable block with its elastic face form a yielding
limiting stop for the movement of the indenting point. The other end of the said
lever extends beyond the indenting point and receives inward pressure from a spring
which is secured to the rim of the recorder-plate, opposite to the said block, and
presses the said lever and the indenting point inwardly, so as to give the centre of the
diaphragm a slight inward bend, producing an initial strain upon the diaphragm.
Between the end of the said spring and the said lever, a piece of india-rubber is
placed. The lever being rigid in its construction and in its support by the long
bearing, prevents any vibration of the indenting point; while the adjustable limit-
stop, formed by the block and rubber, limits the movement of the diaphragm to a
small compass.
The
This construction of recorder has been found exceedingly. effective in use.
diaphragm is highly sensitive and responds accurately to speech-vibrations. The
movement of the indenting point is quite free within exceedingly small limits; but
the resistance to its movement increases enormously as the extent of the movement is
increased. Hence the importance of the fundamental tones in the operation of the
instrument is reduced, while the hissing tones which produce movements of a small

page_text: extent are given an undue importance in the record. This makes the reproduced
sound clear and intelligible, since the hissing sounds are brought out clearly and can
be distinguished from the scraping noises of the instrument.
It will be observed that the diaphragm is under constant tension and can have no
movement at all, except that which is permitted by the elasticity of the yielding
limit-stop. Heretofore the diaphragm of the phonograph-recorder and the indenting
point have not been limited in their forward movement except by the capacity of the
diaphragm for vibration. This has permitted strong waves, owing to great momentum
and the small amount of energy stored up as a retracting force, to give abnormal and
untruthful vibrations to the diaphragm. With the present recorder, the diaphragm
does not force the lever forward into space, but compresses matter always in contact,
viz.: the rubber. Hence nearly all the work is stored up in the compression of the
rubber to effect the return movement; and the momentum becoming a small factor
compared to the power stored up, the diaphragm is not given untruthful vibrations.
This principle of construction of the recorder is termed by the inventor a closed or
constrained system of movement, as distinguished from the open or free system of
movement heretofore employed.
The reproducer employed is also an improved instrument of great effectiveness.
It has a plate, similar to the recorder-plate, which is held removably in the corrre-
sponding eye, in the same way that the recorder-plate is held in its eye. This
reproducer-plate has an opening through it, which is brought into line with the tube
for bringing the reproducer into operative relation with the phonogram-cylinder.
The reproducer-plate is recessed at its back and has stretched across it a diaphragm,
which is preferably a thin animal membrane. This diaphragm is secured in place
by a ring which is secured to the back of the reproducer-plate; while the diaphragm
is stretched by another ring which has a neck screwing into the opening of the
reproducer-plate and is capable of being turned by a tool, so as to stretch the diaphragm
more or less. To one edge of the ring is secured a fine spring-wire, which is long
enough to reach from the point where it is secured to the centre of the diaphragm,
and has its inner end turned downwardly to follow the spiral line of indentations
upon the phonogram. The inner end of this spring-wire is attached to the centre
of the diaphragm by a strip of rubber; the tendency of the spring-wire being to
bend away from the diaphragm, so that it strains the small rubber strip and places
the diaphragmn under an initial tension. The movement of the point of the wire in
reproducing is so slight that the strain is never wholly removed from the rubber
strip; and hence the diaphragm is always under tension, which tends to draw it
outwardly at the centre." This makes the instrument exceedingly sensitive and
capable of reproducing sounds accurately; the end of the wire being rounded and
burnished, it will not obliterate the phonogram-record even though that record be
made in quite soft material.
The inventor has found that by connecting the reproducing point with the diaphragm
by a strip of elastic material, such as rubber held under tension, the proper wave
motion is transmitted to the diaphragm ; but the scratching noises, which seem to
require molecular transmission, are largely obliterated.
The indenting point of the recorder has an appreciable width, while the reproducing
point of the reproducer is much finer. Hence the track of indentations on the phono-
gram will be much wider than the reproducing point; and the adjustment of the
reproducing point laterally with respect to the indented track need not be extremely
accurate. Should the reproducing point be found to rest only on the edge of the
indented track, which will be indicated by imperfect reproduction, the adjustment of
one of the set-screws upon the horns of the carrying arm while the listening
tube is held to the ear, will cause the spectacles to be adjusted so as to bring the
reproducing point sufficiently into the indented track to give the required clearness
of reproduction.
It will be observed that both the recorder and reproducer are complete instruments,
each in itself, held by a plate readily removable from the machine. This enables

page_text: these instruments, which are delicate parts of the apparatus, to be readily removed
from the machine for repair, adjustment or replacement by other similar parts. As
has been previously stated, the phonogram-cylinder is slightly taper. This is also
true of the bore of the phonograms, which are constructed of a cylinder of some
hard material, and covered with a recording surface of wax or wax-like substance.
The recording surface is a true cylinder; while, as before stated, the internal bore of
the cylinder is tapered to fit the phonogram-cylinder; so that the phonogram can be
pushed upon the cylinder, and will be held thereon by friction. The base for the
wax-like coating is in the preferred form of the phonogram, moulded from a plastic
material, such as plaster of Paris, which is strong and light, and does not change its
shape or size materially under atmospheric conditions. Instead of using plaster of
Paris, I may mould the base from sealing wax, from asphalt, or from a mixture of
shellac with sand, sawdust or other suitable material.
It is proposed to make these phonograms the entire length of the phonogram-
cylinder and also to divide such full-length phonograms into parts, so that sectional
phonograms will be produced, which will be, for illustration, one fourth, one half, and
three fourths the length of the full-sized phonogram. All of these sectional phono-
grams as well as the full-sized phonogram, will have the taper bore, so that they can
be pushed upon the taper phonogram-cylinder until they bind, and the instrument
can then be adjusted to them for recording and reproducing. By having the
phonogram-cylinder mounted upon the horizontal shaft, outside of the bearing, the
phonograms can be slipped on and off the cylinder without disturbing any part of the
machine. Upon the guide-rest is marked a graduated scale by which the reproducing
instrument for reproducing from any part of the phonogram can be set. A phono-
gram may have upon its surface the record of two or more letters or other papers or
memoranda and a note may be filed with the phonogram stating between what
numbers on the scale each letter or memorandum is recorded on the phonogram.
This will enable the instrument to be set for reproducing the exact letter or
memorandum by adjustment with reference to the scale.
A pan may be slipped under the phonogram-cylinder upon the frame for receiving
the shavings from the phonogram when the cutter is being used.
For the control of the instrument, it is only necessary that a proper circuit-breaker
should be placed in the circuit between the battery and the motor, so that the motor
can be stopped and started at will. It will be observed that by raising the recorder
or reproducer off the phonogram-cylinder, the yielding guide block, which takes into
the lead-screw, will also be raised out of engagement with the lead-screw; and
although the phonogram-cylinder continues to turn, the recorder or reproducer is not
advanced. This enables an operator of the instrument to set the instrument back
any distance he may desire to reproduce over again any portion of the matter which
he has misunderstood or desires to have repeated.
As an additional feature of construction, it is proposed to provide the phonograph
with a heated burnishing tool for burnishing the wax-like surface of the phonogram
in rear of the cutting tool. This improves the articulation of the phonograph, since
the effect is to smooth out the tool-marks produced in turning the phonogram-surface
to a true cylinder, and to reduce greatly the scratching noise heard in the recorder,
and consequently made a part of the record which is reproduced by the reproducer.
It may be effected by causing the shank of the cutting tool, adjustable by means of a
nut, to pass through the travelling holding arm. There is also carried by the extension
on the arm a heated burnishing tool. This is adjustable by means of a screw, and acts
upon the phonogram-surface after the cutting tool.
The burnishing tool may be composed of a platinum strip or wire to which heavier
wires or rods lead. These rods are connected, by a flexible cord, with a battery for
supplying a current for heating the strip or wire. The strip or wire is heated to a
dull red, and is made to bear lightly on the wax or wax-like surface of the phonogram.
The heat may, however, be produced by a small alcohol lamp, which is carried by the
guide-sleeve and travels with the holding arm. The burnishing tool in this latter

page_text: arrangement may be a silver or aluminium wire, say one eighth of an inch in diameter
and reduced to one thirty-secondth of an inch at its burnishing end, such end being
heated by conduction from the lamp. The end of the wire above the flame of the
lamp may carry a plate, so that the tool can be adjusted without disturbing the
influence of the lamp. The wire will be held by parts constructed of a material
which is a poor conductor of heat.
The phonogram is a cylinder slipping over the phonogram-cylinder. It has a
surface of wax, or of wax-like material, on a base of harder material, such as plaster
of Paris. The phonogram may be turned and burnished before being placed on the
phonogram-cylinder of the phonograph; but it is preferred to have the cutting and
burnishing tools upon the phonograph itself, since the phonogram can then be turned true
to the cylinder of the machine, and can have the record removed from its surface so
that the phonogram can be used over and over again.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C.,
Agent for the Applicant.

page_text: Improvements in Phonographs and Phonograms.
I, GEORGE EDWARD GOURAUD, of Little Menlo, Beulah Hill, in the County of
Surrey, late Colonel in the United States Army, do hereby declare the nature of this
invention (a communication to me from abroad by Thomas Alva Edison, of Llewellyn
Park, in the County of Essex and State of New Jersey, one of the United States of
America) and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
The object of this invention is, generally, to so improve the phonograph that it will
be well adapted for use by the public, and will be a convenient and efficient machine
for various uses. More especially the object is to improve the recording and reproducing
qualities of the instrument, to provide a proper motor for running the phonogram-
cylinder at an uniform speed, to provide a suitable phonogram-cylinder and phonogram,
and to arrange and construct the several parts of the machine so that its manipulation
will be simple, readily understood and convenient for the purposes for which the machine
is designed.
In the accompanying drawings
Figure 1 is a top view of the machine.
Figure 2 a horizontal section on the line 2-2 in Figure 3, with a diagram of the
motor-connections.
Figure 3 a vertical section on the line 3-3 in Figure 1, with swinging holder and
guide-arm thrown back.
Figure 4 an elevation of the machine, looking at the end of the phonogram-
cylinder.
'
Figure 5 a top view of the swinging holder, carrying the recorder and reproducer.
Figure 6 a side elevation of the guide-arm.
Figure 7 a sectional view, on an enlarged scale, showing the engagement of the
spring-guide-block with the lead-screw.
Figures 8 and 9 are a bottom view and central section respectively of the recorder.
Figures 10 and 11 a bottom view and central section respectively of the reproducer.
Figure 12 is an elevation of the guide-rest.
Figure 13 a sectional view of a phonogram, showing, by dotted lines, its division
into sections.
Figure 14 an elevation showing the four different sizes of the phonogram.
Figure 15 is an end elevation of the phonogram-cylinder, the phonogram and the
holding arm, showing a heated burnishing tool applied to the phonograph.
and
Figure 16 a top view of the parts of Figure 15 with the holding arm broken away;
Figures 17 and 18 are views similar to Figures 15 and 16, showing a modified form
of the heated burnishing tool.
With reference to Figures 1 to 14 of the drawings:
The frame of the machine is constructed, for convenience, of a top and a bottom

page_text: plate, A, B, each constructed as a spider composed of four arms, the ends of the arms
of the two frames being joined by vertical posts a. To these posts are connected the
yokes of four magnets, C, C¹, 02, 03, each projecting from the post to which it is
attached towards the adjoining post to which its pole-pieces are connected by braces b
of brass or other non-magnetic metal. The poles of the four magnets project inwardly
as shown, and are cut with concave faces; the poles of all four magnets being in the
line of a circle. Within this circle, mounted upon a vertical shaft a, is a fly-wheel D',
constructed of brass and having a heavy rim so as to increase its weight. Upon the
periphery of the rim of the fly-wheel are secured a number of armatures D2 of iron,
which are placed vertically, equal distances apart, and travel in their movement close
to the pole-pieces of the magnets C, C1, C2 and 03. Upon the shaft D, above the
wheel D¹, is mounted a sleeve d of insulating material, upon which is secured a metal
collar e, and above this collar a commutator f; the commutator being composed of a
ring of metal having its surface broken by blocks of insulating material, so that it
presents alternate spaces of insulation and metal in a manner well understood. From
the collar e projects an arm d in a radial direction, and upon the end of this arm is
pivoted a swinging weight-arm d², which, by its outward movement, moves a lever d³,
which is held against its movement by an adjustable spring d. The lever d³ bears
normally upon an insulated contact-screw d, which is connected by a wire with the
base of the commutator f. The magnets C, C, C2 C3, have one end of their windings
connected together by a wire 2. The other end of the windings of the two opposite
magnets C and C² are connected together by a wire 3; while the other ends of the
windings of the other opposite magnets C and C³ are connected together by a wire 4.
The wires 3 and 4 are connected with two springs and 2, which bear upon the
face of the commutator f. A spring bears directly upon the collar e. These three
springs are supported by a circular piece of insulation g, which is supported above the
wheel D¹ and below the top plate by means of posts extending down from the top
plate. The motor is driven by a battery or other source of electricity. One pole of
the battery E which drives the motor is connected with the wire 2, which joins one
end of the windings of all the magnets; while the other pole of the battery is connected
with the spring f3 bearing upon the collar e. The parts are arranged so that the fly-
wheel D will be turned by the magnets always in the direction shown by the arrow
in the drawings. The magnets C and C² first receive the current and attract two
armatures upon the wheel, and then the magnets C and C³ receive the current and
attract two armatures upon the wheel; the current being transferred from one pair of
magnets to another in succession, so that the wheel is given a continuous rotary
movement. An excess of battery power is preferably used, and the speed of the wheel
controlled by the governor, formed by the spring-retracted arms d² and d³. This
governor opens the circuit when the speed exceeds the normal, so that, within limits
of variation which are so small as to be practically of no effect in the operation of
the machine, the speed will be kept uniform. By the adjustment of the spring (4,
the governor can be made to work at any desired point. By the use of an electro-
magnetic motor of this description, namely, one composed of a heavy fly-wheel
carrying armatures on its periphery which are attracted by magnets arranged in a
circle around the fly-wheel, a slow and uniform motion can be obtained, which is a
matter of the highest importance in the operation of the phonograph and tends to
simplify the construction, since the complication introduced by the employment of a
number of speed-reducing wheels is avoided. Projecting from the collar e, on the
opposite side to the governor, is an arm g¹ carrying a weight at its end for counter-
balancing the weight of the governor, so that the wheel may be a balanced one.
The shaft D is stepped on a jewel g at the centre of the bottom plate A, giving
freedom of movement to the wheel and reducing the noise of friction to the minimum,
so as not to materially affect the operation of the phonograph. Upon the top plate A
is journalled the horizontal shaft F, this shaft being carried by a journal-box / in the
top of an arched standard hat the centre of the top plate, and at one end by a
journal-box at the end of one of the arms of the top plate. Between the bearings h
and, the shaft F is larger than it is outside of such bearings, so that it bears
B

page_text: against the inner faces of the bearings by shoulders which prevent any longitudinal
movement of the shaft. The shaft F projects beyond the bearing h to the opposite
side of the machine from the bearing 2, but is not supported at its end; it being
free to receive the phonogram-cylinder G, which is slipped upon this shaft, pre-
ferably removably, and held by a spring-pin h³ taking into a hole in the end of
the shaft.
This phonogram-cylinder is made hollow, of brass or other suitable metal, its heads
bearing upon the shaft so as to centre the cylinder properly. The cylinder is made
slightly taper for a purpose which will be presently explained; its inner end, that next
to the bearing h, being somewhat larger than its outer end. The inner end of the
phonogram-cylinder is constructed as a bevelled friction-wheel i, upon which bears a
bevelled pinion of some suitable soft material. This pinion i is mounted upon the
upper end of the shaft D which projects through the top plate into the space between
the legs of the arched standard . "The pinion may be provided with an operative
face of leather, or other similar material, mounted upon a metal hub. This metal hub
is preferably constructed to slide vertically upon the shaft D, it being prevented from
turning thereon by a suitable key; and beneath the pinion is a spiral spring, which
forces the pinion upwardly and keeps it solidly against the bevelled wheel on the inner
end of the phonogram-cylinder, so that the wear of the surfaces is taken up and the
pinion is kept in firm contact. By the use of this bevelled friction gearing, of which
the soft-surfaced pinion is a part, the motion is changed from the vertical shaft of the
motor to the horizontal shaft of the phonogram-cylinder without the production of
noise which would be detrimental to the operation of the instrument. The horizontal
arrangement of the motor permits a large fly-wheel to be used, while the compactness
of the instrument is maintained. Between the bearings and 2, the shaft F is cut
with an exceedingly fine screw-thread of the peculiar construction which will be
explained further on; while outside the bearing the shaft is provided with a
hand-wheel j, by which the shaft can be held when it is desired to remove the
phonogram-cylinder therefrom, or to remove the phonogram from the phonogram-
cylinder without taking the latter off the shaft. Parallel with the shaft F and located
in the rear of the same, is a guide-rod H, mounted in suitable supports at its ends and
extending entirely across the machine. Upon this guide-rod is an accurately fitting
tube, which is of such length that it can be moved upon the rod, between the
supports at the ends of the rod, a distance equal to the length of the phonogram-
cylinder. Upon the end of this tube next to the phonogram-cylinder is secured the
holding arm which carries the recorder and reproducer; while at the opposite end of
this tube is the guide-arm 7 which engages with the lead-screw j. The guide-arm 7 is
rigid and has a hub which slips on the tube k, and is secured thereto by a set-screw.
This guide-arm projects toward the shaft F, terminating at its free end above the
screw-thread j. The end of the arm 7 is slotted, so as to form two guide-cheeks
between which plays a vertically-sliding block . This block bears upon the
screw-thread and is cut with a section of the corresponding thread. A spring 12
extends along the top of the arm 7 and is secured to the block 1', forcing such block
downwardly upon the screw-thread, so that a rocking movement of the tube k can be
made within certain limits without disengaging the block from the screw-thread j.
The screw-thread ; and the thread upon the block are cut as fine as it is possible to
make a screw-thread having the desired wearing capacity. This screw-thread is
preferably made with about one hundred threads to the inch; and in order to make
such a fine thread do the work required of it without danger of the guide arm being
forced back, these threads are formed like ratchet-teeth, as shown in Figure 7; the
engaging sides of the threads being straight and the other sides bevelled, so that the
danger of slipping backward is entirely obviated. Upon the other end of the tube k
is secured the-arm I by means of a set-screw; such arm projecting forward over the
centre of the phonogram-cylinder. Upon the upper end of this arm I is pivoted the
holding frame I, placed nearly at right angles to the arm I, and made similar to
the frame of spectacles with two eyes m, m². The pivot-screw m² for this frame.
passes through the frame at one side and centrally between the eyes m m³, the nut for
j

page_text: the
securing the frame bearing upon the spring-washer beneath it, so that the frame will
hold itself at either limit of its throw and will not be jarred from position. The arm
1
has two horns m³ through which the set-screw m passes for limiting the movement of
the frame I and for adjusting the point at which the frame will be stopped when
swung in either direction, so as to bring its holding eyes in the correct relation to the
phonogram-cylinder. These holding eyes carry the recorder and reproducer, the
construction of which will be presently explained; and the object of the swinging
frame is to permit either the recorder or reproducer to be brought into operative
relation with the phonogram-cylinder. The eyes m m³ have fingers n n¹, which
project forward and have passing through them adjusting screws n², which rest, as
each eye is brought into position for operation, upon a guide-rest K which extends
parallel to the shaft F in front of the phonogram-cylinder and supports the holding
frame at the required elevation to bring the recorder or reproducer into accurate
adjustment. The fingers nn have small handles attached to them, as shown in
Figure 4, by which the swinging holding frame can be more conveniently manipulated.
Behind the guide-rod H there is another rest H¹ to receive the arm I when it is thrown
back. This rest is preferably more or less springy in its character, so as not to jar tho
parts injuriously when the arm is thrown back upon it. Passing through the arm I,
near the tubek, is the shank of a cutting tool L, which is thrown forward by a
spring o on the inner side of the arm, and is retracted by a thumb-nut o' on the
screw-threaded end of the shank outside of the arm. This cutter L is designed to
turn off the surface of the phonogram, so as to make it true for recording; or to
turn off one record and leave the surface ready for another record. This enables one
phonogram to be used over and over again for recording and reproducing
recorder and reproducer being brought into operative relation with the clear surface,
as the diameter of the phonogram-cylinder is decreased, by the adjustment of the
screws n the yielding guide-block permitting this to be done. Upon the arm 1,
above the holding frame for the recorder and reproducer, is secured a carrying plate M
to which is connected a tube M'. This tube serves as the mouth- and ear-piece of the
instrument, or it may have mouth- and ear-pieces removably attached to it. The
plate M is stationary and the holding eyes are swung under it alternately, so that one
tube answers both for recording and reproducing; thus adding to the simplicity of
the instrument. The recorder N is a circular plate which fits either eye, m or m³, of
the carrying frame; it being provided with a rib engaging with a groove in the eye,
so that it will always have the same position in the eye. It is shown as held by the
eye m'. A set-screw p is used for holding the plate in the eye. This plate N has an
opening p' through it, which is brought into line with the tube M when the eye m' is
swung into position for the operation of the recorder. The back of the plate N is
recessed to form a circular chamber on a shoulder in which is placed the diaphragm N¹,
which is preferably made of celluloid or some other light material and is placed in the
recess at the back of the plate N, but is left free at its edges. The recording point p²
is secured to the centre of the diaphragm by wax or in any other suitable way. This
point is constructed of a thin plate of steel, which is cut or ground to a point on one
edge and is bevelled backwardly away from that edge so as to give a support for the
indenting point and prevent vibration of that point in operation. This point passes
through the end of the lever p³ and is secured therein by a set-screw p₁, the point
being surrounded between the lever and the diaphragm by a small tube p of rubber
or other suitable material. The lever p³ is rigid in its construction and is mounted
upon a cross-pin po of considerable length, which is journalled at its ends at the sides
of the plate N. The lever 2³ extends beyond the pivot-pin p and rests at its outer
end against a block 7, which is faced with a piece of pure India-rubber . This
block is set in a recess in the edge of the plate N and is adjusted forward by a
screw . The adjustable block g and its elastic face q form a yielding limiting stop
for the movement of the indenting point. The other end of the lever på extends
beyond the indenting point p² and receives inward pressure from a spring 73 which
is secured to the rim of the plate N opposite to the block and presses the lever p³ and
the indenting point inwardly, so as to give the centre of the diaphragm a slight inward

page_text: bend, producing an initial strain upon the diaphragm. Between the end of the
spring and the lever p³ a piece of India-rubber is placed. The lever being
rigid in its construction, and in its support by the long bearing, prevents any vibration
of the indenting point; while the adjustable limit-stop, formed by the block q and
rubber g', limits the movement of the diaphragm to a small compass.
This construction of recorder has been found exceedingly effective in use. The
diaphragm is highly sensitive and responds accurately to speech-vibrations. The
movement of the indenting point is quite free within exceedingly small limits; but
the resistance to its movement increases enormously as the extent of the movement
is increased. Hence the importance of the fundamental tones in the operation of the
instrument is reduced, while the hissing tones which produce movements of a small
extent are given an undue importance in the record. This makes the reproduced
sound clear and intelligible, since the hissing sounds are brought out clearly and can
be distinguished from the scraping noises of the instrument.
It will be observed that the diaphragm is under constant tension and can have no
movement at all, except that which is permitted by the elasticity of the yielding
limit-stopy. Heretofore the diaphragm of the phonograph-recorder and the indenting
point have not been limited in their forward movement except by the capacity of the
diaphragm for vibration. This has permitted strong waves, owing to great momentum
and the small amount of energy stored up as a retracting force, to give abnormal and
untruthful vibrations to the diaphragm. With my present recorder, the diaphragm
does not force the lever forward into space, but compresses matter always in contact:
viz., the rubber 7. Hence nearly all the work is stored up in the compression of g
to effect the return movement; and the momentum becoming a small factor com-
pared to the power stored up, the diaphragm is not given untruthful vibrations.
This principle of construction of the recorder is termed by the inventor a closed or
constrained system of movement, as distinguished from the open or free system of
movement heretofore employed.
The reproducer employed is also an improved instrument of great effectiveness. It
has a plate o, similar to the plate n, which is held removably in the eye m¹ in the
same way that the plate n is held removably in the eye m¹. This plate o has an
opening a through it, which is brought into line with the tube M' for bringing the
reproducer into operative relation with the phonogram-cylinder. The plate o is
recessed at its back and has stretched across it a diaphragm o', which is preferably a
thin animal membrane. This diaphragm is secured in place by a ring ', which is
secured to the back of the plate o; while the diaphragm is stretched by another
ring, which has a neck screwing into the opening of the plate and is capable of
being turned by a tool so as to stretch the diaphragm o more or less. To one edge
of the ring is secured a fine spring-wire u³, which is long enough to reach from
the point where it is secured to the centre of the diaphragm, and has its inner end
turned downwardly as shown, to follow the spiral line of indentations upon the phono-
gram. The inner end of this spring-wire u³ is attached to the centre of the diaphragm
by a strip of rubber; the tendency of the spring-wire being to bend away from
the diaphragm, so that it strains the small rubber strip and places the diaphragu
under an initial tension. The movement of the point of the wire in reproducing
is so slight that the strain is never wholly removed from the rubber strip *; and
hence the diaphragm is always under tension, which tends to draw it outwardly at the
centre. This makes the instrument exceedingly sensitive and capable of reproducing
sounds accurately; the end of the wire being rounded and burnished, it will not
obliterate the phonogram-record, even though that record be made in quite soft
material.
The inventor has found that by connecting the reproducing point with the
diaphragm by a strip of elastic material, such as rubber held under tension, the proper
wave motion is transmitted to the diaphragin; but the scratching noises, which seem
to require molecular transmission, are largely obliterated.
The indenting point of the recorder has an appreciable width, while the reproducing
point of the reproducer is much finer. Hence the track of indentations on the

page_text: phonograph will be much wider than the reproducing point and the adjustment of
the reproducing point laterally with respect to the indented track need not be
extremely accurate. Should the reproducing point be found to rest only on the edge
of the indented track, which will be indicated by imperfect reproduction, the adjust-
ment of one of the screws m³, while the listening tube is held to the ear, will cause
the spectacles to be adjusted so as to bring the reproducing point sufficiently into the
indented track to give the required clearness of reproduction.
It will be observed that both the recorder and reproducer are complete instruments,
each in itself, held by a plate readily removable from the machine. This enables
these instruments, which are delicate parts of the apparatus, to be readily removed
from the machine for repair, adjustment or replacement by other similar parts. As
has been previously stated, the phonogram-cylinder is slightly taper. This is also
true of the bore of the phonograin P, the same being constructed of a cylinder of
some hard material and covered with a recording surfaces of wax or wax-like sub-
stance. The recording surface s is a true cylinder, while as before stated the internal
bore of the cylinder is tapered to fit the phonogram-cylinder; so that the phono-
gram can be pushed upon the cylinder and will be held thereon by friction. The
baser for the wax-like coating s is, in the preferred form of the phonogram, moulded
from a plastic material, such as plaster of Paris, which is strong and light, and does
not change its shape or size materially under atmospheric conditions. Instead of
using plaster of Paris, I may mould the base from sealing wax, from asphalte or
from a mixture of shellac with sand, sawdust or other suitable material.
It is proposed to make these phonograms the entire length of the phonogram-
cylinder; and also to divide such full-length phonograms into parts, so that sectional
phonograms will be produced, which will be, for illustration, one-fourth, one-half,
and three-fourths the length of the full-sized phonogram. All of these sectional
phonograms, as well as the full-sized phonogram, will have the taper bore, so that
they can be pushed upon the taper phonogram-cylinder until they bind, and the
instrument can then be adjusted to them for recording and reproducing. By having
the phonogram-cylinder mounted upon the shaft F, outside the bearing, the
phonograms can be slipped on and off the cylinder without disturbing any part of
the machine. Upon the guide-rest k is marked a graduated scale t, by which the
reproducing instrument for reproducing from any part of the phonogram can be set.
A phonogram may have upon its surface the record of two or more letters or other
papers or memoranda; and a note may be filed with the phonogram stating between
what numbers on the scale t each letter or memorandum is recorded on the phono-
gram. This will enable the instrument to be set for reproducing the exact letter or
memorandum by adjustment with reference to the scale t.
As shown in Figure 4, a pan T may be slipped under the phonogram-cylinder G upon
the frame A for receiving the shavings from the phonogram when the cutter Lis
being used.
For the control of the instrument, it is only necessary that a proper circuit-breaker
should be placed in the circuit between the battery and the motor, so that the motor
can be stopped and started at will. It will be observed that by raising the recorder
or reproducer off the phonogram-cylinder, the yielding guide-block", which takes
into the lead-screw j, will also be raised out of engagement with the lead-screw; and
although the phonogram-cylinder continues to turn, the recorder or reproducer is not
advanced. This enables an operator of the instrument to set the instrument back any
distance he may desire to reproduce over again any portion of the matter which he
has misunderstood or desires to have repeated.
With reference to Figures 15 to 18 of the drawings:
As an additional feature of construction, it is proposed to provide the phonograph
with a heated burnishing tool for burnishing the wax-like surface of the phonogram in
rear of the cutting tool. This improves the articulation of the phonograph, since the
effect is to smooth out the tool-marks produced in turning the phonogram-surface to
a true cylinder, and to reduce greatly the scratching noise heard in the recorder, and
consequently made a part of the record which is reproduced by the reproducer. This

page_text: feature is shown in Figures 15 to 18, to which especial reference is now made. Gis
the revolving phonogram-cylinder. I is the travelling holding arm mounted on the
guide-sleeve I and carrying the recorder and reproducer; the arm and sleeve being
fed laterally by a lead-screw on the shaft of the phonogram-cylinder, as will be well
understood. The frame 1', carried by the arm I, rests upon the guide-rest K, it being
adjustably supported thereon by a set-screw n². Through the arin I passes the shank
of the cutting tool L, adjustable by means of the nut o'. There is also carried by an
extension on the arm I the heated burnishing tool R. This is adjustable by means of
the screw and acts upon the phonogram-surface after the cutting tool. In
Figures 15 and 16, the burnishing tool is composed of a platinum strip or wire to
which heavier wires or rods lead. These rods el are connected by a flexible cord V
with a battery for supplying a current for heating the strip or wire v. The strip or
wire is heated to a dull red, and is made to bear lightly on the wax or wax-like
surface of the phonogram. In Figures 17 and 18, the heat is produced by a small
alcohol lamp W, which is carried by the guide-sleeve I and travels with the holding
The burnishing tool in this latter arrangement may be a silver or aluminium
wire 1, say one-eighth of an inch in diameter and reduced to one thirty-second th of
an inch at its burnishing end, such end being heated by conduction from the lamp.
The end of the wire w above the flame of the lamp may carry a plate w¹ so that the
tool can be adjusted without disturbing the influence of the lamp. The wire
will be held by parts constructed of a material which is a poor conductor
of heat.
arm.
ひ
The phonogram P is a cylinder slipping over the phonogram-cylinder G. It has a
surface of wax, or of wax-like material, on a base of harder material, such as plaster
of Paris. The phonogram may be turned and burnished before being placed on the
phonogram-cylinder of the phonograph; but it is preferred to have the cutting and
burnishing tool upon the phonograph itself, since the phonogram can then be turned
true to the cylinder of the machine, and can have the record removed from its
surface, so that the phonogram can be used over and over again.
Having, now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I claim :-
1st: An improved recording phonograph constructed and operating substantially
as herein described.
2ndly An improved reproducing phonograph constructed and operating sub-
stantially as herein described.
:
3rdly An improved recording and reproducing phonograph constructed and
operating substantially as herein described.
:-
4thly In a phonograph, the combination, with a horizontal shaft carrying a
phonogram-cylinder, of a vertical shaft connected with the horizontal shaft through
friction gearing, and provided with a governed electro-magnetic motor comprising a
fly-wheel with armatures on its rim attracting electro-magnets located around the
fly-wheel and furnished with a suitable commutator, substantially as and for the
purposes herein set forth.
5thly In a phonograph, the use of a swinging spectacle-frame carrying both
the recorder and the reproducer, and adapted to be swung so as to bring either
the one or the other into operative relation with the phonogram, substantially as
herein described.
6thly In a phonograph, the use of a guide-rest serving to carry the recorder
and reproducer and to determine the relation of each to the phonogram, substantially
as herein described.
7thly In a phonograph, the use of a yielding guide-block permitting the
adjustment of the holding arm with relation to the phonogram without disengaging
the guide-block from the lead-screw, substantially as herein described.
Sthly In a phonograph, the combination, with the revolving phonogram-cylinder,
of the lead-screw on the cylinder-shaft, the moving guide-sleeve having the guide-arm
projecting therefrom and carrying a yielding guide-block engaging with the lead-screw,

page_text: the holding arm projecting from the said guide-sleeve over the phonogram-cylinder, a
guide-rest in front of the phonogram-cylinder, and an adjusting screw supporting
the holding arm upon the guide-rest, substantially as and for the purposes herein
set forth.
9thly In a phonograph, the use of a cutting tool arranged or operating
substantially as herein described for turning off the surface of the phonogram.
10thly In a phonograph, the use of a heated burnishing tool arranged or
operating substantially as herein described for burnishing the surface of the
phonogram.
:-
11thly In a phonograph, mounting a phonogram-cylinder upon a shaft outside
the bearings of the latter, substantially as herein described, whereby a removable
cylindrical phonogram may be readily slipped on and off said cylinder.
12thly In a phonograph, the use of a phonogram-cylinder having a taper bore,
substantially as herein described.
13thly The use of sectional phonograms, substantially as herein described.
14thly
The improved construction of cylindrical phonogram having a taper bore
and a cylindrical recording surface, substantially as herein described.
15thly The improved manufacture of hollow cylindrical phonograms substantially
as herein described; same having a base moulded from plastic material, which
becomes hard and substantially unchangeable, and a coating of softer material for
receiving the phonographic record.
16thly The improved construction of phonograph-recorder, operating upon a
constrained or closed system of movement, substantially as herein described.
17thly The improved construction of phonograph-reproducer, operating sub-
stantially as herein described, and having its point mounted upon or connected with
a spring which tends to throw the point away from the diaphragm, such point being
connected by a strained elastic strip with the diaphragm, whereby the diaphragm is
given an initial tension which is not entirely overcome by the movement of the
point.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C.,
Agent for the Applicant.