MEANS FOR RECORDING SOUNDS, AND SUCH RECORD." IN REPRODUCING SUCH SOUNDSROM
Year: 1878

page_text: LETTERS PATENT to Thomas Alva Edison, of Menlo Park in the State of New
IMPROVEMENT IN
Jersey, United States of America, for the Invention of
MEANS FOR RECORDING SOUNDS, AND
SUCH RECORD."
IN REPRODUCING SUCH SOUNDS FROM
PROVISIONAL SPECIFICATION left by the said Thomas Alva Edison at the
Office of the Commissioners of Patents on the 24th April 1878.
THOMAS ALVA EDISON, of Menlo Park, in the State of New Jersey, United
States of America. IMPROVEMENT IN MEANS FOR RECORDING SOUNDS, AND
REPRODUCING SUCH SOUNDS FROM SUCH RECORD."
IN
My present improvements are for more fully developing and perfecting the devico
heretofore invented by me, and known as the phonograph." By extensive
experiment and research I have been enabled to obtain very perfect articulation
and to produce a record in a convenient form for preservation.
The sound vibrations are made to move a point that by preference is a diamond
or other very hard substance and of a peculiar shape. The sound vibrations in
the atmosphere act upon a diaphragm or other body capable of motion, and the
same moves the indenting point, and acts as a phonograph. The indented material
is properly designated a phonogram, and it is preferably metallic. Sometimes tiu-
foil is used upon a grooved surface; sometimes a thin sheet or leaf of metal is
placed upon a piece of paper having a surface of parafin or similar material.
Sometimes the metallic surface is copper, and where a matrix has been made of
steel or iron by electrotype deposit, or otherwise, upon the phonogram it may be
hardened and used for impressing a sheet or roller of metal, and thereby the original
phonogram can be reproduced indefinitely in metal that may be hardened and used
for any reasonable length of time to utter the sentence, or words, or sounds
phonetically.
The instrument or portion of the instrument that reproduces the sound from the

page_text: •
"
phonogram I term a phonet.** In order to facilitate production, use, and
preservation of the phonograms I employ a ring or margin of thick paper or paste-
board, caused to adhere to the foil or sheet by resinous substance; this is used as a
gauge in placing the sheet in the instrument or replacing the same in the phonet.
I find that a disc revolved by gearing, and a weight or spring, and the movement
regulated by a fan or governor, is a convenient device for presenting the surface to
be indented to the phonograph, and the phonograph is on an arm that swings
towards and from the centre of the disc, and is guided by grooves or other convenient
mechanism.
The phonet device takes the place of the phonograph device when the sounds are
to be reproduced.
When the sheet of material is wrapped around a cylinder its edges are passed
down into a slit and held firmly. Either the cylinder may be moved endwise by a
screw, or the phonograph or phonet devices be moved along the cylinder, and where
the same sound is to be reproduced periodically, as calling out the hours of the day
in a clock, or reproducing the sounds of animals in toys, the phonet is to be brought
to the place of beginning automatically.
The phonographic devices employed by me are preferably a diaphragm of metal,
against which the sound vibrations act." Sections of rubber tube applied to the
surface act as dampers to prevent false vibrations; pieces of felt or similar yielding
material may be used for the same purpose, and a small delicate hoop of spring
metal between the diaphragm and the indenting point renders the phonogram more
perfect than it would be if the diaphragm acted upon the point direct. A similar
effect is produced by a disc upon the arm that carries the point, said disc being so
close to the diaphragm that the atmosphere will produce the vibrations. It is often
advantageous to use a case between the mouth of the speaker and the diaphragm
to gather or hold the sound, and in some instances the head of the speaker should
be inserted into this case up through a hole in the bottom. The mouth-piece is
sometimes slotted or perforated, and has irregular edges to re-inforce the hissing
sounds, and sometimes a membrane of rubber or gutta percha is fitted to the feeth,
and forms a bag between the lips and the diaphragm.
The disc upon the arm that carries the point as aforesaid may be acted upon by
a, magnet, and the current through a helix from a diaphragm, or the motion of the
arm and points may serve to set up a secondary current through such helix in con-
sequence of the motion given by the phonogram to the point. The arm carrying
the point in this latter case should be magnetised.
The phonogram may be produced by the direct action of air concentrated to the
spot by a funnel terminating with a small hole, the end of the funnel being almost
in contact with the moving surface to be indented.
When the foil is perforated instead of indented it can be rolled up in the form of a
horn or cylinder, and revolved, and the articulation result from air blown from the
end of a small tube passing through the perforations as they are presented in
succession. Leverage is sometimes" employed between the diaphragm and the
phonogram, either to lessen or increase the motion of the phonographic action in
recording, or of the phonetic action in speaking, and for recording quartette, trio,
and other characters of singing, two, three, four, or more phonographic devices are
employed upon one cylinder or plate, and the sounds will be reproduced by
corresponding phonets; or where singing is conveyed through tubes to one diaphragm
the phonographic record will be the combined tones, and the reproduction by the
phonet will be complete and correct.
1 find that an arm at right angles to a diaphragm, with a point resting upon the
phonogram, will reproduce the tones by the weight and leverage of the arm moving
the diaphragm. The phonogram may be in the form of a disc, a sheet, an endless
helt, a cylinder, a roller, or a belt, or strip, and the marks are to be either in straight
lines, spiral, zig-zag, or in any other convenient form, so long as the apparatus is
adapted to bring the same in contact with the phonet or speaking part of the
apparatus, and the reproduction of the phonogram from a matrix or copy in relief

page_text: of an original phonogram may he made upon a belt, roller, cylinder. plate, or other
convenient surface.
For
For amusement and instruction this phonograph is capable of extended use.
instance, a revolving cylinder containing phonograms of the letters of the alphabet
and phonet keys, with corresponding letters on them, can be used in teaching the
alphabet and phonogram sentences, speeches, and other matters can be spoken by
the phonet and repeated by the learner without the eyesight being called into use.
For amusement or instruction the phonogram can be of a dog's bark. a rooster's
crow, a bird's song, a horse's neigh, a lion's roar, and the like, and the phonogram
can be used in a toy animal with a single phonet for the reproduction of the original
sound.
This phonograph or speaking machine applied to a mask produces a semblance of
vitality if the phonogram is made to operate upon moveable lips by levers, and in
the production of such a phonogram a portion of the surface is to be indented by
delicate levers and points, receiving motion from the lips during articulation; thereby
a correct reproduction of the motion of the lips is obtained.
In connection with the phonet it is important to avoid the sound that usually
results from the rubbing action of the phonogram upon the point. I am enabled to
prevent this by an electric action between the point and the phonogram. In this
case the phonogram should be of iron, and the point of steel and the parts magnetised
so as to slightly repel each other; the point will follow the undulations and reproduce
the sounds by the phonet. It is important that the point used in the phonet
correspond in shape to that of the phonograph, but slightly smaller, so as to follow
the bottom of the depressions without contact upon the sides. The diaphragm or
other body employed in the phonet to receive motion from the phonogram is
connected with a funnel of paper or other resonant substance that acts as a sounding
board to render the phonet louder and more distinct.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Alva Edison in the Great Seal Patent Office on the 22nd
October 1878.
THOMAS ALVA EDISON, of Menlo Park, in the Siate of New Jersey, United
States of America. IMPROVEMENTS IN MEASS FOR RECORDING SOUNDS, AND
REPRODUCING sten SoUNDS FROM SUCH RECORD."
IN
This Invention consists in means for recording in permanent characters the
sounds made by the human voice in speaking and singing, those made by musical,
instruments, hirds, animals, or any sound whatever, and in means for reproducing
those sounds at any desired time.
11
"
..
The sound vibrations act upon a diaphragm or other hody capable of motion:
this diaphragm is at the back of a chamber provided with an opening or mouth-
piece, and to this diaphragm an indenting point is secured. This instrument I term
phonograph." The phonograph is adjusted to position with its indenting point
contiguous to a moving surface covered with a thin sheet of metal foil or other
suitable material, or else the surface with the metal foil is stationary, and the pho-
nograph movable. The surface upon which the metal foil is secured is by preference
grooved spirally, and this indenting point indents the foil in the line of this groove
als the diaphragm is moved back and forth by the sound vibrations: these
indentations are al record of the sound waves, and form the characters. for
This indented sheet I term
reproducing the sounds.
The
}} phonogram.
instrument or portion of the instrument that reproduces the sound from the
phonogram I term a phonet." It is similar in construction to the phonograph.
being provided with a diaphragm and point. but the mouth-piece is by preference
funnel-shaped to render the sound loud and distinct. The sounds are reproduced by
the phonet being adjusted to place so that the point of its diaphragm is at the
beginning of the spiral line of indentations. and as the surface containing the
indented foil is moved the diaphragm of the phonet is vibrated by the point passing
from one indentation to the next, hence the diaphragm receives the same movement.
from the indentations as when making those indentations, consequently the sounds
made by the phonet will be the same as those that operated upon the diaphragm
of the phonograph.
In the Drawing Fig. 1 is a section of the phonograph and sectional elevation of
the mechanism for presenting the surface to be indented; and Fig. 2 is a plan of
the same.
The phonograph is made of the body portion a. diaphragm . and indenting
point c. The body portion a has a central opening forming the mouth-piece into
which the person speaks, or through which opening the sound vibrations pass to act
upon the diaphragm, and the diaphragm is secured at its edges to the body a.
Jeaving a space between the body and diaphragm in order that the diaphragm
may vibrate freely. The indenting point should be a diamond or other very hard
substance. The diaphragm is made of a thin sheet of iron or other material. and it
is preferable to place the indenting point upon a delicate spring arm, and to
employ a short piece of rubber tubing between the spring and diaphragm: this
rubber acts as a damper to prevent false vibrations of the diaphragm. The
phonograph is upon a lever arm i pivoted at 5 to the vertical stud 6, so that the
phonograph may be raised or lowered vertically, or moved horizontally for a
purpose hereafter explained.
It is now to he understood that if a person speaks with his mouth near the
mouth-piece of the phonograph the sound, vibrations will act upon the diaphragm,
and vibrate it, and communicate to the indenting point a similar movement, and

page_text: 20
that if a piece of metal foil or other material susceptible of being indented is placed
beneath or behind the indenting point and caused to move regularly, or the indenting
point moved over the material, that said material will be indented and form à
perfect record of the sound vibrations. I will now. describe the means for
sustaining the sheet to be indented, and the mechanism for moving the same:-
is a disk or plate secured to and turning with the shaft c, and hinged to this
disk is a ring frame f: this disk d has two spiral grooves 3, 4, in its surface.
There are pins 2, 2, upon the surface of the disk, and holes at corresponding places
in the ring frame; the sheet to be indented is of a size and shape to correspond
with that of the disk and frame f, and said sheet has holes in it corresponding
to the position of the pins 2. 2, and these holes form register marks in placing or
replacing the sheet upon the disk d, and after the sheet is so placed the ring frame f
is brought down upon the sheet and holds it firmly in place. There may be a
central opening in the indented sheet of a size slightly larger than the space
Occupied by the spiral 3, and the outer edges of the sheet are stiffened by a ring of
thick paper or pasteboard caused to adhere by glue or other adhesive material.
The surface of the disk is made with two spiral grooves 3 and 4 as aforesaid:
the groove is a guide for a pin that is upon an arm g on the phonograph, and
the groove is for the indenting point c. As the disk and sheet are revolved the
groove causes the indenting point to occupy a position immediately over the
line of the spiral 4, and the indentations will be made upon the sheet of foil in a
line corresponding to that of the spiral 4, shown in Fig. 2. The indentations made
in the foil are complete record of the sound vibrations that acted upon the
diaphragm b, and from this indented sheet, which I term a phonogram," the sounds
are reproduced. The phonograph is carried outwardly by the spiral 3, and in so
doing the parts swing upon the vertical stud 6. By depressing the outer end of
the lever the phonograph is raised so that it can be swung aside from the disk d
to allow of the ring frame f being thrown back and the indented sheet or
phonogram removed from the disk. The shafte is revolved by, a weight or
spring, and gearing at h, and the spring is wound up by moving the lever back
and forth, which acts upon a ratchet and pawl of ordinary construction; / is a
lever provided at its outer end with an inclined groove, in which is a pin on the
lever . and the other end of this lever mis connected with the coupler by
moving the lever one way or the other, the shaft e will be connected to or
disconnected from the gearing h, and hence the disk d stopped or started at
pleasure without interfering with the motor.. As it is necessary that the shaft e
should be revolved with uniformity I provide a governor at n to prevent the
apparatus revolving too rapidly; and this may he made as in Figs. 1, 3, & 4, in
which there are metal blocks at the ends of spring arms from a cross head on a
shaft that is driven by the gearing h. said blocks swinging radially and acting
against the interior of a stationary cylinder if the speed becomes too great,
thereby checking the speed by the friction of the blocks against the cylinder.
These spring arms may be secured at one end to a prismatic block as shown in
Fig. 5.
It is preferable to cover the surface of the blocks next the cylinder p
with felt or similar material that will slide upon the interior surface of the
cylinder p. but produce more or less friction, according to the centrifugal action.
"
*
The guide spiral 3 may be dispensed with, and either of the devices shown in
Figs. 6, 7, 8, or 9 made use of. In Figs. 6 and 7 the shaft projects above the
surface of the disk d. and there is a tooth upon the shaft contiguous to a rack bar
extending from the phonograph, hence each revolution of the shaft. the rack bar.
and phonograph will be moved the space of one tooth. conséquently the lines of
indentations will be parallel and concentric to the shaft e, excepting at the places
when the tooth acts to move the rack bar and phonograph outward or inward:
this case the spiral grooves are cut to correspond to the feed. In Fig. S a worm
upon the shaft e acts upon a worm pinion to revolve the shaft and the worm at
the other end of this shaft e acts upon teeth around the base of the lever on the
stud 6. By this device the phonograph will be moved outward gradually, and the
In

page_text: line of indentations will be in a spiral corresponding to the continuous spiral groove
in the plate d.
In Fig. 9 the shaft e is made with a fusee at 21, and one end of a swinging arm
connected to the phonograph takes against the same. The spirals of the fusee
gradually move outward the phonograph, as the disk and shaft are revolved, and
the line of indentions will be spirally the same as that made by the spiral 3.
In Fig. 10 the shaft e is provided with a screw pinion meshing with teeth upon
a cam wheel 7. This gives the same movement to the phonograph as the spiral
groove 3.
In Fig. 11 the guide groove 3 for the arm and pin g is upon a disk d¹ upon the
shafte, but the groove occupies the same relative position upon the disk d¹ as
the groove 4 upon the disk d, so that the phonograph is moved outwardly by the
groove of the disk d', swinging both the arms and upon the vertical pivot 6.
Instead of the sheet of metal foil being upon the disk d it may be wrapped upon
a cylinder, as in Fig. 12. In this case the cylinder is upon a shaft e revolved by
the gearing at ', and upon said shaft there is a right and left hand screw at ki,
and there is a corresponding double spiral groove in the surface of the cylinder q.
The phonograph is secured to a sliding shaft, and said shaft is moved endwise
back and forth by the screw acting upon an arm m² that is secured to the said
shaft As the phonograph is moved in one direction the line of indentations is
made spirally in the foil on the cylinder 1, and when the arm m² reaches the end
of the screw it willbe moved in the other direction by the reverse screw thread,
and the phonograph will make a second spiral line of indentations that will cross
the first spiral line. This feature is especially available for a phonet where the
surface of the cylinder 7 is formed of an electrolyte or other copy of the phonogram.
so that the words or sounds may be reproduced automatically and at intervals if
desired. It is preferable to make use of a thin metal plate n², see Figs. 13 and 14,
pivoted at one end and fitting within a longitudinal groove in the surface of the
cylinder g for securing the edges of the metal foil and holding it securely upon said
cylinder. The top of this plate n² is flush with the surface of the cylinder, and
grooved to correspond with the grooves in the cylinder, so as not to interfere with
the indenting point. A wire may replace this device, such wire being secured by
arms at each end of the cylinder, and raised and lowered in and out of the groove
by a cam or otherwise. I find that an interruption of one-eighth of an inch space
where there is no recording is not detected by the ear.
The apparatus shown in Figs. 13 and 14 is similar to that shown in Fig. 12,
except that the phonograph is stationary and the cylinder moves horizontally, and
the shaft is only provided with a screw thread in one direction, hence the
cylinder will have to be moved back by hand to bring it to place if desired to
reproduce the sounds from the phonogram, or to position the phonograph if a new
sheet of foil is to be indented after the first one has been removed. This is readily
accomplished by raising the arm o¹ and its tooth from the screw, which leaves
the shaft and cylinder free to be moved back and forth. In Fig. 15 the
phonograph is fitted to move horizontally instead of the cylinder 7, as in Fig. 12,
but the shaft is provided with a screw thread in one direction only, hence the
phonograph has to be positioned by hand after the arm o¹ has been raised from the
screw In Figs. 12 and 15 the phonograph can swing upon the shaft to raise
the indenting point from the cylinder g. and allow for the removal or insertion of
a sheet of foil, and there is a stop at 8 for adjusting the position of the phonograph
when brought down to indent the foil.
In Figs. 13 and 14 the phonograph is upon an arm pivoted at 9, so that it can
bo swung horizontally away from the cylinder g for the purpose aforesaid, and the
adjustable stop 8 is also provided.
"
Thus far I have described the "phonograph' or instrument upon which the
sound vibrations act, and which instrument acts to indent the sheet of foil and
produce the "phonogram "or record of such sound vibrations. Mechanism has also
been described for presenting the sheet of foil to be indented by the phonograph.

page_text: I will now describe how the sounds are reproduced from the phonogram. If it is
desired to reproduce the sounds from the phonogram in the same instrument in
which the phonogram was produced it is only necessary that the indenting point & be
made to traverse the line of indentations in the phonogram, and that a funnel-
shaped mouth-piece, shown by dotted lines in Fig. 1, be added to the phonograph
to aid in increasing the loudness and distinctness of the sound. The instrument in
this form 1 term a phonet."
"
As
lu the instrument shown in Figs. 1, 2, 6, 7, 8, 9, 10, 11, 13, 14 and 15, the
phonet requires to be positioned by hand, as before explained, in order that the
point may be placed at the beginning of the spiral line of indentations.
the point passes from one indentation to the next, either by the foil being
moved beneath said point, as in Figs. 1, 2, 6, 7, 8, 9, 10, 11, 13, and 14, or by the
point moving over the foil, as in Figs. 12 and 15, the diaphragm receives a move-
ment corresponding to the depth of the indentations, and corresponding also with
the same movement it received from the sound vibrations when making those
indentations, hence air waves will be produced by the movement of the diaphragm
that will make sounds by passing through the mouth-piece of the phonet that
will be exactly the same as the sounds that acted upon the diaphragm of the
phonograph.
The material upon which the record is made may be of metal foil, such as tin,
iron, copper, lead, zinc, cadmium, or a foil made of composition of metals. Paper
or other materials may be used, the same being coated with parafine or other
hydrocarbons, waxes, gums, or lacs, and the sheet so prepared may itself be
indented, or the material, say paper, may be made to pass through a bath of hot
parafine, and thence between scrapers. Thin metal foil is now placed on the
material, and the sheet passed through rollers, which give it a beautiful smooth
surface. The indentation can now be made in the foil, and the parafine or similar
material, and the indenting point, does not become clogged with the parafine in
consequence of the intervening foil. If the copper foil, or tin foil with copper
surface is used, and a matrix of iron or steel made by electrotype deposit or
otherwise upon the phonogram, such matrix may be hardened and used for
impressing a sheet or roller of metal as hereafter mentioned; thereby the original
phonogram can be reproduced indefinitely in metal that may be hardened and
used for any reasonable length of time to utter the sentence or words or sounds
phonetically.
I will now briefly describe some modifications in the construction and operation
of the phonograph and phonet.
In Fig. 16 the indenting point e is upon a spring arm, as in Figs. 1 and 2, but
there are short sections of rubber tube es at each side of the diaphragm to
dampen the diaphragm and prevent false vibrations. In Fig. 17, the rubber of the
diaphragm acts against the outer end of the arm to increase the leverage and
lessen the depth of indentations in the foil and allow of the record being made in
less yielding material than tin foil. Fig. 18 shows a modification of the last-
mentioned device, the pressure being applied to the arm between the indenting
point and the support for the arm so as to increase the depth of the indentations.
Fig. 19 shows the arm c² made as a lever with a spring. Fig. 20 shows the
indenting point upon the center of a spring bar that is firmly held at each end:
the bar is connected at its center to the diaphragm by a string or otherwise.
Fig. 21 represents the diaphragm bas of concave form instead of flat. Fig. 22
shows the indenting point upon a spring secured to the diaphragm.
Fig. 23 shows a disk upon the spring e of the indenting point: this disk
is placed quite close to the diaphragm and is moved by the air as the diaphragm is
vibrated. The disk being so close to the diaphragm that the two will vibrate
together, as air cannot pass between or escape as rapidly as the vibrations take
place.
Fig. 24 shows the diaphragm vibrated by electro-magnetism; in this case the
diaphragm is to be of iron, and the power of the electro-miguet will be varied by a

page_text: rise and fall of electric current passing through the helix of the electro-magnet;
this rise and fall of electric tension is to be produced by the action of sound upon
a diaphragm and connections in an electric circuit. Fig. 25 shows the method of
vibrating the indenting spring and point by the direct action of an electro-magnet
without the use of a diaphragm, the electric tension in the helix being varied by
sound vibrations upon a diaphragm. Fig. 26 shows the spring arm connected to
one end of a permanent magnet so as to highly magnetize the reproducing point;
the foil should be of iron. When the point passes an indentation there will be less
attraction than when passing no indentation; this will give good articulation free
from the scraping noise of the point on the foil, for in this case it does not touch
the foil, but is worked by magnetic attraction. Fig. 27 represents two instruments
in connection with the cylinder q; in this case the phonet and the phonograph are
separate. The phonograph records in the usual manner, but the phonet has its
diaphragm set in motion by the rise and fall of the lever ². This reduces the
scraping noise of the foil and acts by leverage, and a slight tension to move the
Fig. 28 shows an
diaphragm as the phonogram is moved beneath the point c.
arrangement whereby four persons may speak simultaneously and have records
made in separate parallel lines upon one cylinder, and the phonogram will reproduce
the sounds the same as though it contained the record of but one voice. Fig. 29
shows a single phonograph adapted to receive the voices of three persons as in
singing the sounds made by the three voices are conveyed through flexible or
other tubes to the diaphragm, and will be recorded in a single line of indentations,
but when reproduced by the phonet the sounds uttered will correspond to the three
voices.
lu Fig. 30. the foil is sustained upon a hollow cylinder with a funnel-shaped end.
The record is made upon the foil in the usual manner by the phonograph, excepting
A nozzle with a small opening is
that holes are made entirely through the foil.
placed so that it will always be opposite the line of perforations as the cylinder is
revolved. This nozzle is connected to a source of compressed air or other fluid,
and every time a perforation comes opposite the nozzle, a puff of air passes into
the cylinder and a sound is produced upon the principle of the siren. The nozzle
be placed on a spring to keep the end of the nozzle in contact with the line
of perforations.
may
Fig 31 shows the phonograph as made with a large chamber between the
diaphragm and the mouth-piece; this is especially useful in collecting sound when
the person speaking or the sound to be recorded is made several feet from the
instrument. Fig. 32 shows a device whereby the indenting point may be dispensed
with in the phonograph. The funnel forming the phonograph is made with a
diaphragm at the larger end or mouth-piece, and a very small hole at the pointed
end adjacent to the foil on the cylinder ; this foil should be very thin so that the
indentations will be made by the direct action of the air waves as concentrated by
the funnel without the interposition of the indenting point. Fig. 33 shows a
phonet in which the phonogram or sound record has been made upon an endless
belt this is a convenient arrangement for toys, as the same may be made to
imitate the bark of a dog or other noise made by an animal; and this belt may be
of steel or other hard material that allows the same to be used for a long period
of time.
Fig. 34 is a perspective view showing a double phonet, there being a spiral line
of indentations on each side of the revolving disk d, one phonet coming into action
as the other finishes in this case the spirals should be in opposite directions, so
that the disk continuing to revolve in the same direction moves one phonet from
the center outwards, and then the other phonet is connected and moved back
towards the center; this may be used as a toy.
sentence,
Fig. 35 represents a phonet in which the phonogram containing a
speech, words, or other sound record is upon a belt or strip wound upon a reel;
this belt is drawn along gradually and wound upon the second roller by any
suitable mechanism, and as the phonogram is thus moved it actuates the

page_text: phonet c, b. Fig. 36 shows a phonograph or phonet similar to that shown in
Fig. 12, the cylinder y is revolved, but remains in one position, and the phonograph
or phonet is movable back and forth over the cylinder. In this instance the
arm mis extended beyond the screw, and passes beneath the inclined spring
guide m³, when the screw is carrying the arm and phonograph towards the right;
as the arm m passes from beneath the end of the guide it is no longer held to
the screw, and the arm m² and phonet are lifted by the guide as the springs m
draws the shaft, phonograph, and arm, along to the place of beginning, at which
place the arm m² drops off the end of the inclined guide m into the thread of the
Screw, and as this revolves it carries the arm along beneath the guide m³ as before,
Fig. 37 represents the phonograph or phonet upon a pivoted arm, so that it may
swing across or at right angles to the line of movement of the intended material
or phonogram. In this case the line of indentations may be lengthwise of the belt,
or across the same as in the are of a circle. Fig. 38 shows a phonograph similar to
that shown in Fig. 31. except that the sound chamber is of a different shape.
Fig. 89 shows a mouth-piece with an orifice of soft rubber to fit the mouth or
the lips of the person speaking, so that all sound waves will be confined to the
chamber and diaphragm. Fig. 40 shows the mouth-piece of the phonograph made
with cross slots with irregular edges. Fig. 1 shows the mouth-piece as perforated
with numerous holes. Fig. 42 shows but one opening in the mouth-piece; the
edges of this are irregular. These irregular edges reinforce the hissing sounds, and
cause a more perfect phonogram to be produced. Fig. 43 represents a mouth-piece
of mica with a central opening protected at its edges by a wooden ring. In Fig. 44
the diaphragm bis of wire gauze with a backing of paper connected to it by any
suitable cement, and there is a ring of stiff paper at the edges of the gauze disk to
strengthen it. Fig. 45 represents a diaphragm of parchment or similar material
stretched tightly within the frame by cords and screws. The cords may be of
different lengths and tension, and respond to and reinforce certain sounds. Fig. 46
shows a mouth-piece for the phonet made in imitation of the human mouth.
Fig. 47 represents the body portion of the phonograph or phone made triangular,
and the diaphragm is of corresponding shape. Fig. 48 represents three cylinders,
cach provided with a phonograph or phonet: this is useful in recording and repro-
ducing three-part singing or music. Fig. 49 represents a phonet made as a tube.
with flaring or trumpet-shaped ends, and with two diaphragms 15, 16. placed
crosswise of the tube so as to form an air chamber. There is a third diaphragm b.
which is vibrated by the movement of the reproducing point, and said diaphragm
gives motion to the air in the chamber, and vibrates the diaphragms 15, 16. which
latter produce air waves, and the sounds issuing from the two frumpet-shaped ends
will blend and increase the volume of sound. Fig. 50 represents a device whereby
deep indentations are made in the metal foil. Two diaphragms are employed, the
first () is vibrated by the sound vibrations, and controls a valve in
connected with a source of compressed air or other fluid; this valve 67 allows more
or less air to pass to the diaphragm b, according to the vibration of the diaphragm .
hence the diaphragm 6 will vibrate in harmony with the diaphragm . but it will
he acted upon by greater force, and consequently the indentations will be deeper
in the foil than if the diaphragm was acted upon simply by the sound vibrations
of the voice. Figs. 51 and 52 represent a device that may be used with a phonet
to increase the loudness of the sounds reproduced. The sound vibrations from the
phonet are conducted by a tube shown by dotted lines in Fig. 51, to the diaphragm
that controls a valve in a tube connected with a reservoir of air or other flui
under pressure, and the air as it escapes by the valve passes into the trumpet-
shaped end of the tube, and produces sounds that are very loud and clear, and are
a reproduction of the sounds resulting from the use of one of the phonels before
described. This same apparatus may be used to reproduce with louder utterances a
person's voice, the sound from the voice being used to vibrate the diaphragm b³,
and thereby regulate the air waves escaping from the valve into the trumpet.
Fig. 5 shows the speaker's head within a box or case; in this instance nearly all
a tube

page_text: the sound vibrations act upon the diaphragm. Figs. 54 and 55 illustrate how the
movements of the lips in speaking may be recorded and reproduced. In this
instance, a lever applied to the diaphragm carries the indenting point c, Fig. 55.
and the end of this lever is placed in the mouth of the speaker, and the movement
of the lips regulates the indentations in the foil. A similar apparatus shown in
Fig. 54 within a case is connected to the movable lips of a mask, so that these lips
open and close as in articulation, at the same time that the sound vibrations are
given by the phonogram to the phonet. Fig. 56 represents a toy phonet in which
the phonogrami strip 35 is secured at one end to a cylinder upon which it is wound.
By pulling upon the strip it is unwound, and a rubber cord 37 is wound upon the
shaft of the cylinder. When the hand is removed from the indented strip, the
rubber cord rotates the shaft and winds up the phonograph upon the cylinder, and
the sounds are reproduced in the phonet by the phonogram acting upon a point
and diaphragm . The movement of the shaft is regulated by the fan, worm, and
pinion 38. In Fig. 57, the cylinder for moving the phonogram strip is shown as
provided with pins that enter holes in the edges of the strip; this causes the strip
to be fed along very regular. In Fig. 58, the cylinder with pius is shown as made
with heads to act as guides for the strip. Fig. 59 shows a re-indenting device for
amplifying or increasing the size of the indentations. There are two rollers, one
of which travels faster than the other a³, and there is a lever 40 pivoted at 41,
and provided with a point c for each cylinder. One point follows the indentations
in the cylinder, and the other rests upon a, and as this travels the fastest. the
indentations made therein will be longer and also deeper by the point being at the
outer end of the lever. In Fig. 60, one roller 42 of the pair is made of hardened
metal with the sound record in relief. This is obtained by electrotype or other
process from an iron foil or other metal phonogram, and this roller is used to indent
strips or sheets of foils or rollers to produce copies that can be used with the phonet.
Fig. 6 represents a roller 42 of hardened metal with the record in relief, and
arranged so as to knurl or indent the phonogram in a roller 43 of soft metal that
is to be pressed against the roller 42 by a screw or other suitable means. The
cylinder having a spiral groove in its surface may be made by placing the mould
shown in Fig. 62 around a cylinder or shaft, and filling the space between the
cylinder and mold with plaster of Paris or other suitable material. The mold is of
metal with a screw or spiral rib projecting therefrom, and it is made in two parts
and hinged so that it can easily be removed when the plaster of Paris is dry. For
amusement or instruction, the phonograph is capable of extended use; for instance,
a revolving cylinder, see Fig. 63. containing rows of indentations representing the
letters of the alphabet, and provided with keys containing corresponding letters,
can be used in teaching the alphabet, and sentences, speeches, and other matter can
be spoken by the phonet, and repeated by the learner without the eyesight being
called into use. Clocks may be provided with phonogram cylinders or wheels to
call off the hours. to give alarms, &c. The phonogram may be upon a strip, sheet,
belt, or roller, and it can he of a dog's bark, a rooster's crow, a bird's song, a horse's
neigh, and these can be used in toy animals with a simple phonet for reproducing
the sound. In copying phonograms, or making duplicates, an original phonogram
may receive a deposit of copper or iron in a plating bath; and, if of iron, may be
carbonized to convert it into steel and hardened, and then the same should be
'backed up with type metal, and use for impressing strips or pieces of metal.
A bed of gutta percha, or similar material, may be used to sustain the sheet
metal while being pressed. Numerous copies of the original phonogram can thus
be reproduced. A plaster cast can be used for producing a copy by pressure.
The
governor to regulate the speed of the instrument may be made of a pendulum
weight 61. see Fig. 64. bung at the lower end of a rod that is provided with an
universal joint at. 62, and the upper end of the rod is moved around by a crank 63
that is revolved by the train of gearing. As the speed increases the weight will
describe a circle of larger diameter, and thereby increase the resistance. The
universal joint may be displaced by a spring wire, Fig. 65. that allows of the

page_text: movement. A magnet 64 upon the crank arm 63 Fig. 66. may be used to revolve
the pendulum by attracting an armature at the upper end of the pendulum rod,
and thereby avoid the friction resulting from the contact of the surfaces of the
pendulum rod with the crank. In Fig. 67 the diaphragm is represented as con-
nected to a pair of delicate piston valves within a tube GS that has three ports;
one 69, is connected to a reservoir of compressed air, the others, 70 and 71, are
connected to a chamber 12 at opposite sides of a diaphragm, so as to vibrate the
same in harmony with the diaphragm . but there will be greater amplitude given
to the same by the pressure of the air, and by a connection to the phonet
diaphragm the sound produced will be greatly increased.
What I claim as my Invention is.-
First. The combination with the diaphragm and point of a flat receiving surfaco
and means for revolving the receiving surface, and causing the point to follow
a volute or spiral line, substantially as represented in Figs. 1. 2, 6. 7. 8. 9, 10,
and 34.
Second. The combination with the revolving plate phonograph or phonet of a
propelling weight or spring and a governor to regulate the speed, and ensure
uniformity of movement. substantially as set forth.
Third. A revolving disk provided with a clamping frame to secure the foil or
other material in combination with the swinging arm, diaphragm, and point, sub-
stantially as specified.
Fourth. In a phonograph or phonet. a spring introduced between the diaphragm
and the point, substantially as set forth and shown in Figs. 16, 17, 18, 19, 22,
and 26.
Fifth. In a phonograph or phonet, a rubber spring, or similar device, to dampen
the vibration of the diaphragm. and prevent false vibrations, as set forth and shown
in Figs. 16 and 21.
Sixth. The combination with the diaphragm in a phonograph or phonet apparatus
of a lever to modify the relative action of the diaphragm and point, substantially
as described, as shown in Figs. 17, 18, 27.
Seventh. The combination with the diaphragm and point of a permanent or electro-
magnet, substantially as described and represented in Figs. 24. 25. 26.
Eighth. The method of recording and reproducing two or more sounds or speeches
simultaneously, substantially as described, and as illustrated by Figs. 28, 29,
and 48.
Ninth. A phonet composed of a perforated sirene and a jet tube, substantially as
described, and represented in Fig. 30.
Tenth. The mechanism for producing a phonogram, and employing the same in a
phonet, substantially as described, and illustrated in Figs. 32, 33, 35, 36, and 37.
Eleventh. The combination with the phonograph. diaphragm, and point of a
sound chamber. substantially as described, and illustrated in Figs. 31, 38, 39,
and 58.
Twelfth. The diaphragm and mouth-pieces for a speaking phonograph, substantially
as described, and illustrated in Figs. 41, 42, 43, 44, 45. and 46.
Thirteenth. The combination with a diaphragm and its point of two diaphragms
for the purposes, and substantially as shown in Figure 49.
Fourteenth. The combination with a diaphragm and valve actualed by sound
vibrations a source of compressed fluid and a trumpet, as in Figs. 51, 52, or il
phonograph as in Fig. 50, substantially as set forth.
Fifteenth. The combination of two diaphragms with a valve and a source of
compressed fluid. as represented in Fig. 67, for increasing the volume of the voice
or other sound, as set forth.
Sixteenth. The combination with two or more phonograms of phonet keys for
selecting letters or utterances as described. and illustrated in Fig. 63.
Seventeenth. The means for duplicating or reproducing phonograms from an
original phonogram, substantially as set forth.
Eighteenth. The combination with the phonograph or phonet of the revolving

page_text: crank and pendulum governor, substantially as described and shown in Figs.
64, 65, 66.
Nineteenth. The combination with the phonograph of a lever moved by the lips.
and of a lever and phonet to move the lips of a mask, substantially as described,
and illustrated by Figs. 55 and 54.
Twentieth. The combination with a phonogram of a clock movement or toy and
a phonet for reproducing sounds for clocks or toys, substantially as set forth.
In witness whereof. I. the said Thomas Alva Edison, have hereunto set my
hand and seal this 17 day of September, A.D. 1878.
THOMAS ALVA EDISON. (L.S.).
Witnesses,
CHAS. H. SMITH,
76, Chambers St., New York,
HARROLD SERRELL, 76, Chambers St., New York.

page_text: "
LETTERS PATENT to Thomas Alva Edison, of Menlo Park, in the State of New
Jersey, United States of America, for the Invention of IMPROVEMENTS IN
MEANS FOR RECORDING SOUNDS, AND IN REPRODUCING SUCH SOUNDS FROM
SUCH RECORD."
Sealed the 6th August 1878, and dated the 24th April 1878.
PROVISIONAL SPECIFICATION left by the said Thomas Alva Edison at the
Office of the Commissioners of Patents on the 24th April 1878.
THOMAS ALVA EDISON, of Menlo Park, in the State of New Jersey, United
States of America. "IMPROVEMENTS IN MEANS FOR RECORDING SOUNDS, AND IN
REPRODUCING SUCH SOUNDS FROM SUCH RECORD."
My present improvements are for more fully developing and perfecting the device
heretofore invented by me, and known as the " phonograph."
By extensive experiment and research I have been enabled to obtain very perfect
articulation and to produce a record in a convenient form for preservation.
The sound vibrations are made to move a point that by preference is a diamond
or other very hard substance and of a peculiar shape. The sound vibrations in
the atmosphere act upon a diaphragm or other body capable of motion, and the
same moves the indenting point, and acts as a phonograph. The indented material
is properly designated a phonogram, and it is preferably metallic. Sometimes tin-
foil is used upon a grooved surface; sometimes a thin sheet or leaf of metal is
placed upon a piece of paper having a surface of parafin or similar material.
Sometimes the metallic surface is copper, and where a matrix has been made of
steel or iron by electrotype deposit, or otherwise, upon the phonogram it may be
hardened and used for impressing a sheet or roller of metal, and thereby the original
phonogram can be reproduced indefinitely in metal that may be hardened and used
for any reasonable length of time to utter the sentence, or words, or sounds
phonetically.

page_text: The instrument or portion of the instrument that reproduces the sound from the
phonogram I term a "phonet."
In order to facilitate production, use, and preservation of the phonograms I
employ a ring or margin of thick paper or pasteboard, caused to adhere to the
foil or sheet by resinous substance; this is used as a gauge in placing the sheet in
the instrument or replacing the same in the phonet. I find that a disc revolved by
gearing, and a weight or spring, and the movement regulated by a fan or governor,
is a convenient device for presenting the surface to be indented to the phonograph,
and the phonograph is on an arm that swings towards and from the centre of the
disc, and is guided by grooves or other convenient mechanism.
The phonet device takes the place of the phonograph device when the sounds are
to be reproduced.
When the sheet of material is wrapped around a cylinder its edges are passed
down into a slit and held firmly. Either the cylinder may be moved end wise by a
screw, or the phonograph or phonet devices be moved along the cylinder, and where
the same sound is to be reproduced periodically, as calling out the hours of the day
in a clock, or reproducing the sounds of animals in toys, the phonet is to be brought
to the place of beginning automatically.
The phonographic devices employed by me are preferably a diaphragm of metal,
against which the sound vibrations act. Sections of rubber tube applied to the
surface act as dampers to prevent false vibrations; pieces of felt or similar yielding
material may be used for the same purpose, and a small delicate hoop of spring
metal between the diaphragm and the indenting point renders the phonogram more
perfect than it would be if the diaphragm acted upon the point direct. A similar
effect is produced by a disc upon the arm that carries the point, said disc being so
close to the diaphragm that the atmosphere will produce the vibrations.
It is often advantageous to use a case between the mouth of the speaker and the
diaphragm to gather or hold the sound, and in some instances the head of the
speaker should be inserted into this case, up through a hole in the bottom. The
mouth-piece is sometimes slotted or perforated, and has irregular edges to re-inforce
the hissing sounds, and sometimes a membrane of rubber or gutta percha is fitted
to the teeth, and forms a bag between the lips and the diaphragm.
The disc upon the arm that carries the point as aforesaid may be acted upon by
a magnet, and the current through a helix from a diaphragm, or the motion of the
arm and points may serve to set up a secondary current through such helix in con-
sequence of the motion given by the phonogram to the point. The arm carrying
the point in this latter case should be magnetised.
The phonogram may be produced by the direct action of air concentrated to the
spot by a funnel terminating with a small hole, the end of the funnel being almost
in contact with the moving surface to be indented.
When the foil is perforated instead of indented it can be rolled up in the form of a
horn or cylinder, and revolved, and the articulation result from air blown from the
end of a small tube passing through the perforations as they are presented in
succession.
Leverage is sometimes employed between the diaphragm and the phonogram,
either to lessen or increase the motion of the phonographic action in recording, or of
the phonetic action in speaking, and for recording quartette, trio, and other
characters of singing, two, three, four, or more phonographic devices are employed
upon one cylinder or plate, and the sounds will be reproduced by corresponding
phonets; or where singing is conveyed through tubes to one diaphragm the phono-
graphic record will be the combined tones, and the reproduction by the phonet will
be complete and correct.
I find that an arm at right angles to a diaphragm, with a point resting upon the
phonogram, will reproduce the tones by the weight and leverage of the arm moving
the diaphragm.
The phonogram may be in the form of a disc, a sheet, an endless belt, a cylinder,
a roller, or a belt, or strip, and the marks are to be either in straight lines, spiral,

page_text: zig-zag, or in any other convenient form, so long as the apparatus is adapted to
bringing the same into contact with the phonet or speaking part of the apparatus,
and the reproduction of the phonogram from a matrix or copy in relief of an original
phonogram may be made upon a belt, roller, cylinder, plate, or other convenient
surface.
For
For amusement and instruction this phonograph is capable of extended use.
instance, a revolving cylinder containing phonograms of the letters of the alphabet
and phonet keys, with corresponding letters on them, can be used in teaching the
alphabet; and phonogram sentences, speeches, and other inatters can be spoken by
the phonot and repeated by the learner without the eyesight being called into use.
For amusement or instruction the phonogram can be of a dog's bark, a rooster's
crow, a bird's song, a horse's neigh, a lion's roar, and the like, and the phonogram
can be used in a toy animal with a single phonet for the reproduction of the original
sound.
This phonograph or speaking machine applied to a mask produces a semblance of
vitality if the phonogram is made to operate upon moveable lips by levers, and in
the production of such a phonogram a portion of the surface is to be indented by
delicate levers and points, receiving motion from the lips during articulation; thereby
a correct reproduction of the motion of the lips is obtained.
In connection with the phonet it is important to avoid the sound that usually
results from the rubbing action of the phonogram upon the point. I am enabled to
prevent this by an electric action between the point and the phonogram. In this
case the phonogram should be of iron, and the point of steel and the parts magnetised
so as to slightly repel each other; the point will follow the undulations and reproduce
the sounds by the phonet.
It is important that the point used in the phonet correspond in shape to that of
the phonograph, but slightly smaller, so as to follow the bottom of the depressions
without contact upon the sides.
The diaphragm or other body employed in the phonet to receive notion from the
phonogram is connected with a funnel of paper or other resonant substance that acts
as a sounding board to render the phonet louder and more distinct.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Alva Edison in the Great Seal Patent Office on the 22nd
October 1878.
THOMAS ALVA EDISON, of Menlo Park, in the State of New Jersey, United
States of America. " IMPROVEMENTS IN MEANS FOR RECORDING SOUNDS, AND IN
REPRODUCING SUCH SOUNDS FROM SUCH RECORD."
This Invention consists in means for recording in permanent characters th
sounds made by the human voice in speaking and singing, thoso made by musical
instruments, birds, animals, or any sound whatever, and in means for reproducing
those sounds at any desired time.
The sound vibrations act upon a diaphragm or other body capable of motion;
this diaphragm is at the back of a chamber provided with an opening or mouth-
piece, and to this diaphragm an indenting point is secured. This instrument I term
a "phonograph." The phonograph is adjusted to position with its indenting point
contiguous to a moving surface covered with a thin sheet of metal foil or other
suitable material, or else the surface with the metal foil is stationary, and the pho-
nograph movable.
The surface upon which the metal foil is secured is by preference grooved
spirally, and this indenting point indents the foil in the line of this groove as the
diaphragm is moved back and forth by the sound vibrations; these indentations
are a record of the sound waves, and form the characters for reproducing the sounds.
This indented sheet I term a "phonogram."
"
The instrument or portion of the instrument that reproduces the sound from the
phonogram I term a phonet." It is similar in construction to the phonograph,
being provided with a diaphragm and point, but the mouth-piece is by preference
funnel-shaped to render the sound loud and distinct. The sounds are reproduced by
the phonet being adjusted to place so that the point of its diaphragm is at the
beginning of the spiral line of indentations, and as the surface containing the
indented foil is moved the diaphragm of the phonet is vibrated by the point passing
from one indentation to the next, hence the diaphragm receives the same movement
from the indentations as when making those indentations, consequently the sounds
made by the phonet will be the same as those that operated upon the diaphragm
of the phonograph.
In the Drawing Fig. 1 is a section of the phonograph and sectional elevation of
the mechanism for presenting the surface to be indented; and Fig. 2 is a plan of
the same.
The phonograph is made of the body portion a, diaphragm b, and indenting
point c. The body portion a has a central opening forming the mouth-piece into
which the person speaks, or through which opening the sound vibrations pass to act
upon the diaphragm, and the diaphragm is secured at its edges to the body a,
leaving a space between the body and diaphragm in order that the diaphragm
may vibrate freely. The indenting point should be a diamond or other very hard
substance.
The diaphragm is made of a thin sheet of iron or other material, and it is pre-
ferable to place the indenting point upon a delicate spring arm c³, and to employ a
short piece of rubber tubing es between the spring and diaphragmn; this rubber acts
as a damper to prevent false vibrations of the diaphragm.
The phonograph is upon a lever arm i pivoted at 5 to the vertical stud 6, so that
the phonograph may be raised or lowered vertically, or moved horizontally for a
purpose hereafter explained.
It is now to be understood that if a person speaks with his mouth near the
mouth-piece of the phonograph the sound vibrations will act upon the diaphragm,
and vibrate it, and communicate to the indenting point a similar movement, and
that if a piece of metal foil or other material susceptible of being indented is placed

page_text: beneath or behind the indenting point and caused to move regularly, or the indenting
point moved over the material; that said material will be indented and form a
perfect record of the sound vibrations.
I will now describe the means for sustaining the sheet to be indented, and the
mechanism for moving the same :-d is a disk or plate secured to and turning with
the shaft e, and hinged to this disk is a ring frame f; this disk d has two spiral
grooves 3, 4, in its surface. There are pins 2, 2, upon the surface of the disk, and
holes at corresponding places in the ring frame; the sheet to be indented is of a
size and shape to correspond with that of the disk d and frame f, and said sheet
has holes in it corresponding to the position of the pins 2, 2, and these holes form
register marks in placing or replacing the sheet upon the disk d, and after the sheet
is so placed the ring frame f is brought down upon the sheet and holds it firmly in
place. There may be a central opening in the indented sheet of a size slightly
larger than the space occupied by the spiral 3, and the outer edges of the sheet are
stiffened by a ring of thick paper or pasteboard caused to adhere by glue or other
adhesive material. The surface of the disk d is made with two spiral grooves 3
and 4 as aforesaid; the groove 3 is a guide for a pin that is upon an army on the
phonograph, and the groove 4 is for the indenting point c. As the disk and sheet
are revolved the groove 3 causes the indenting point to occupy a position imme-
diately over the line of the spiral 4, and the indentations will be made upon the
shect of foil in a line corresponding to that of the spiral 4, shown in Fig. 2. The
indentations made in the foil are a complete record of the sound vibrations that
acted upon the diaphragm b, and from this indented sheet, which I term a phono-
gram," the sounds are reproduced. The phonograph is carried outwardly by the
spiral 3, and in so doing the parts swing upon the vertical stud 6. By depressing
the outer end of the lever i the phonograph is raised so that it can be swung aside
from the disk d to allow of the ring frame f being thrown back and the indented
sheet or "phonogram" removed from the disk.
"
The shaft e is revolved by a weight, or spring, and gearing at h, and the spring
is wound up by moving the lever back and forth, which acts upon a ratchet and
pawl of ordinary construction; is a lever provided at its outer end with an inclined
groove, in which is a pin on the lever m, and the other end of this lever m is con-
nected with the coupler m' by moving the lever one way or the other, the shaft e
will be connected to or disconnected from the gearing h, and hence the disk d
stopped or started at pleasure without interfering with the motor.
As it is necessary that the shaft e should be revolved with uniformity I provide
a governor at n to prevent the apparatus revolving too rapidly; and this may be
made as in Figs. 1, 3, & 4, in which there are metal blocks o at the ends of spring
arms from a cross head on a shaft that is driven by the gearing h, said blocks
swinging radially and acting against the interior of a stationary cylinder p if the
speed becomes too great, thereby checking the speed by the friction of the blocks
against the cylinder. These spring arms may be secured at one end to a prismatic
block as shown in Fig. 5. It is preferable to cover the surface of the blocks o next
the cylinder p with felt or similar material that will slide upon the interior
surface of the cylinder p, but produce more or less friction, according to the centri-
fugal action.
The guide spiral 3 may be dispensed with, and either of the devices shown in
Figs. 6, 7, 8, or 9, made use of,
In Figs. 6 and 7 the shaft e projects above the surface of the disk d, and there
is a tooth upon the shaft contiguous to a rack bar extending from the phonograph,
hence each revolution of the shaft, the rack bar, and phonograph will be moved the
space of one tooth, consequently the lines of indentations will be parallel and con-
centric to the shaft e, excepting at the places when the tooth acts to move the.
rack bar and phonograph outward or inward. In this case the spiral grooves are
cut to correspond to the feed.
In Fig. 8 a worm upon the shaft e acts upon a worm pinion to revolve the shaft es,
and the worm at the other end of this shaft e acts upon teeth around the base of

page_text: "
the lever i on the stud 6. By this device the phonograph will be moved outward
gradually, and the line of indentations will be in a spiral corresponding to the
continuous spiral groove in the plate d.
In Fig. 9 the shaft e is made with a fusee at p', and one end of a swinging arm
connected to the phonograph takes against the same. The spirals of the fuseo
gradually move outward the phonograph, as the disk and shaft are revolved, and
the line of indentations will be spirally the same as that made by the spiral 3.
In Fig. 10 the shaft e is provided with a screw pinion meshing with teeth upon
a cam wheel 7. This gives the same movement to the phonograph as the spiral
groove 3.
In Fig. 11 the guide groove 3 for the arm and pin g is upon a disk d' upon the
shaft C,
but the groove 3 occupies the same relative position upon the disk d as
the groove 4 upon the disk d, so that the phonograph is moved outwardly by the
groove of the disk ', swinging both the arms g and i upon the vertical pivot 6.
Instead of the sheet of metal foil being upon the disk d it may be wrapped upon
a cylinder q, as in Fig. 12. In this case the cylinder is upon a shaft el revolved by
the gearing at h¹, and upon said shaft there is a right and left hand screw at k³,
and there is a corresponding double spiral groove in the surface of the cylinder q.
The phonograph is secured to a sliding shaft , and said shaft is moved endwise
back and forth by the screw acting upon an arin m² that is secured to the said
shaft . As the phonograph is moved in one direction the line of indentations is
made spirally in the foil on the cylinder q, and when the arm m² reaches the end
of the screw it will be moved in the other direction by the reverse screw thread,
and the phonograph will make a second spiral line of indentations that will cross
the first spiral line. This feature is especially available for a phonet where the
surface of the cylinder 7 is formed of an electrotype or other copy of the phonogran,
so that the words or sounds may be reproduced automatically and at intervals if
desired.
It is preferable to make use of a thin metal plate n², see Figs. 13 and 14, pivoted
at one end and fitting within a longitudinal groove in the surface of the cylinder q
for securing the edges of the metal foil and holding it securely upon said cylinder.
The top of this plate n³ is flush with the surface of the cylinder, and grooved to
correspond with the groves in the cylinder, so as not to interfere with the indenting
point. A wire may replace this device, such wire being secured by arms at each
end of the cylinder, and raised and lowered in and out of the groove by a cam or
otherwise. I find that an interruption of onc-eighth of an inch space where there
is no recording is not detected by the car.
The apparatus shown in Figs. 13 and 14 is similar to that shown in Fig. 12,
except that the phonograph is stationary and the cylinder moves horizontally, and
the shaft e¹ is only provided with a screw thread in one direction, hence the
cylinder will have to be moved back by hand to bring it to place if desired to
reproduce the sounds from the phonogram, or to position the phonograph if a new
sheet of foil is to be indented after the first one has been removed. This is readily
accomplished by raising the arm o' and its tooth from the screw ¹, which leaves
the shaft e and cylinder free to be moved back and forth.
In Fig. 15 the phonograph is fitted to move horizontally instead of the cylinder q,
as in Fig. 12, but the shaft e¹ is provided with a screw thread in one direction only,
hence the phonograph has to be positioned by hand after the arm o' has been raised
from the screw k¹.
In Figs. 12 and 15 the phonograph can swing upon the shaft to raise the
indenting point from the cylinder q, and allow for the removal or insertion of a
sheet of foil, and there is a stop at 8 for adjusting the position of the phonograph
when brought down to indent the foil.
In Figs. 13 and 14 the phonograph is upon an arm pivoted at 9, so that it can
be swung horizontally away from the cylinder q for the purpose aforesaid, and the
adjustable stop 8 is also provided.
Thus far I have described the "phonograph" or instrument upon which the

page_text: sound vibrations act, and which instrument acts to indent the sheet of foil and
produce the "phonogram" or record of such sound vibrations.
Mechanism has also been described for presenting the sheet of foil to be indented
by the phonograph.
I will now describe how the sounds are reproduced from the phonogram.
If it is desired to reproduce the sounds from the phonogram in the same instru-
ment in which the phonograin was produced it is only necessary that the indenting
point c be made to traverse the line of indentations in the phonogram, and that a
funnel-shaped mouth-piece, shown by dotted lines in Fig. 1, be added to the phono-
graph to aid in increasing the loudness and distinctness of the sound. The instru-
ment in this form I term a "phonet."
In the instrument shown in Figs. 1, 2, 6, 7, 8, 9, 10, 11, 13, 14, and 15, the
phonet requires to be positioned by hand, as before explained, in order that the
point e may be placed at the beginning of the spiral line of indentations. As
the point c passes from one indentation to the next, either by the foil being
moved beneath said point, as in Figs. 1, 2, 6, 7, 8, 9, 10, 11, 13, and 14, or by the
point moving over the foil, as in Figs. 12 and 15, the diaphragm b receives a move-
ment corresponding to the depth of the indentations, and corresponding also with
the same movement it received from the sound vibrations when making those
indentations, hence air waves will be produced by the movement of the diaphragm
that will make sounds by passing through the mouth-piece of the phonet that
will be exactly the same as the sounds that acted upon the diaphragmn of the
phonograph.
The material upon which the record is made may be of metal foil, such as tin,
iron, copper, lead, zinc, cadmium, or a foil made of composition of metals.
Paper or other materials may be used, the same being coated with parafine or
other hydrocarbons, waxes, gums, or lacs, and the sheet so prepared may itself be
indented, or the material, say paper, may be made to pass through a bath of hot
parafine and thence between scrapers. Thin metal foil is now placed on the
material, and the sheet passed through rollers, which give it a beautiful smooth
surface. The indentation can now be made in the foil, and the parafine or similar
material, and the indenting point, does not become clogged with the parafine in
consequence of the intervening foil.
If the copper foil, or tin foil with copper surface is used, and a matrix of iron or
steel made by electrotype deposit or otherwise upon the phonogram, such matrix
may be hardened and used for impressing a sheet or roller of metal as hereafter
mentioned; thereby the original phonogram can be reproduced indefinitely in
metal that may be hardened and used for any reasonable length of time to utter
the sentence or words or sounds phonetically.
I will now briefly describe some modifications in the construction and operation
of the phonograph and phonet.
In Fig. 16 the indenting point c is upon a spring arm e², as in Figs. 1 and 2, but
there are short sections of rubber tube c8 at each side of the diaphragm b to dampen
the diaphragm and prevent false vibrations.
In Fig. 17, the rubber of the diaphragm acts against the outer end of the
arm to increase the leverago and lessen the depth of indentations in the
foil and allow of the record being made in less yielding material than tin
foil.
Fig. 18 shows a modification of the last-mentioned device, the pressure being
applied to the arm e between the indenting point and the support for the arm so
as to increase the depth of the indentations.
Fig. 19 shows the arm e² made as a lever with a spring.
Fig. 20 shows the indenting point upon the center of a spring bar that is firmly
held at each end; the bar is connected at its center to the diaphragm b by a string
or otherwise.
Fig. 21 represents the diaphragm bas of concave form instead of flat.
13: 05.1

page_text: Fig. 23 shows a disk upon the spring c² of the indenting point; this disk is
placed quite close to the diaphragm and is moved by the air as the diaphragm is
vibrated, the disk being so close to the diaphragm that the two will vibrate
together, as air cannot pass between or escape as rapidly as the vibrations take
place.
Fig. 24 shows the diaphragm vibrated by electro-magnetism; in this case the
diaphragm is to be of iron, and the power of the electro-magnet will be varied by a
rise and fall of electric current passing through the helix of the electro-magnet; this
rise and fall of electric tension is to be produced by the action of sound upon a
diaphragm and connections in an electric circuit.
Fig. 25 shows the method of vibrating the indenting spring and point by the
direct action of an electro-magnet without the use of a diaphragm, the electric
tension in the helix being varied by sound vibrations upon a diaghragm.
Fig. 26 shows the spring arm e² connected to one end of a permanent magnet so
as to highly magnetize the reproducing point; the foil should be of iron. When
the point passes an indentation there will be less attraction than when passing no
indentation; this will give good articulation free from the scraping noise of the
point on the foil, for in this case it does not touch the foil, but is worked by
magnetic attraction.
Fig. 27 represents two instruments in connection with the cylinder q; in this case
the phonet and the phonograph are separate. The phonograph records in the usual
manner, but the phonet has its diaphragm set in motion by the rise and fall of the
levere. This reduces the scraping noise of the foil and acts by leverage, and a
slight tension to move the diaphragm as the phonogram is moved beneath the
point c.
Fig. 28 shows an arrangement whereby four persons may speak simultaneously
and have records made in separate parallel lines upon one cylinder, and the phono-
gram will reproduce the sounds the same as though it contained the record of but
one voico.
Fig. 29 shows a single phonograph adapted to receive the voices of three persons:
as in singing; the sounds made by the three voices are conveyed through flexible
or other tubes to the diaphragm, and will be recorded in a single line of inden-
tations, but when reproduced by the phonet the sounds uttered will correspond to
the three voices.
In Fig. 30, the foil is sustained upon a hollow cylinder with a funnel-shaped end.
The record is made upon the foil in the usual manner by the phonograph, excepting
that holes are made entirely through the foil. A nozzle with a small opening is
placed so that it will always be opposite the line of perforations as the cylinder is
revolved. This nozzle is connected to a source of compressed air or other fluid, and
every time a perforation comes opposite the nozzle, a puff of air passes into the 4
cylinder and a sound is produced upon the principle of the siren. The nozzle may
be placed on a spring to keep the end of the nozzle in contact with the line of per-
forations.
Fig. 31 shows the phonograph as made with a large chamber between the
diaphragm and the mouth-piece; this is especially useful in collecting sound when 4
the person speaking or the sound to be recorded is made several fect from the
instrument.
Fig. 32 shows a device whereby the indenting point may be dispensed with in
the phonograph. The funnel forming the phonograph is made with a diaphragm
at the larger end or mouth-piece, and a very small hole at the pointed end adjacent 5
to the foil on the cylinder 9; this foil should be very thin so that the indentations
will be made by the direct action of the air waves as concentrated by the funnel
without the interposition of the indenting point.
Fig. 33 shows a phonet in which the phonogram or sound record has been made
upon an endless belt; this is a convenient arrangement for toys, as the same may 5
be made to imitate the bark of a dog or other noise made by an animal; and this

page_text: belt may be of steel or other hard material that allows the same to be used for a
long period of time.
Fig. 34 is a perspective view showing a double phonet, there being a spiral line
of indentations on each side of the revolving disk d, one plionet coming into action
as the other finishes; in this case the spirals should be in opposite directions, so
that the disk continuing to revolve in the same direction moves one phonet from
the center outwards, and then the other phonet is connected and moved back
towards the center; this may be used as a toy.
Fig. 35 represents a phonet in which the phonogram containing a sentence,
speech, words, or other sound record is upon a belt or strip wound upon a reel;
this belt is drawn along gradually and wound upon the second roller by any
suitable mechanism, and as the phonogram is thus moved it actuates the
phonet c, b.
Fig. 36 shows a phonograph or phonet similar to that shown in Fig. 12, the
cylinder q is revolved, but remains in one positson, and the phonograph or phonet
is movable back and forth over the cylinder. In this instance the arm m² is
extended beyond the screw, and passes beneath the inclined spring guide m³,
when the screw is carrying the arm and phonograph towards the right; as tho
arm m² passes from beneath the end of the guide m³ it is no longer held to the
screw, and the arm me and phouet are lifted by the guide m² as the springs mo
draws the shaft, phonograph, and arm, along to the place of beginning, at which
place the arm m² drops off. the end of the inclined guide m into the thread of the
screw, and as this revolves it carries the arm along beneath the guide m³ as
before.
Fig. 37 represents the phonograph or phonet upon a pivoted arin, so that it may
swing across or at right angles to the line of movement of the intended material or
phonogram. In this case the line of indentations may be lengthwise of the belt, or
across the same in the arc of a circle.
Fig. 38 shows a phonograph similar to that shown in Fig. 31, except that the
sound chamber is of a different shape.
Fig. 39 shows a mouth-piece with an orifice of soft rubber to fit the mouth or the
lips of the person speaking, so that all sound waves will be confined to the chamber
and diaphragm.
Fig. 40 shows the mouth-piece of the phonograph made with cross slots with
irregular edges.
Fig. 41 shows the mouth-piece as perforated with numerous holes.
Fig. 42 shows but one opening in the mouth-piece; the edges of this are irregular.
These irregular edges reinforce the hissing sounds and cause a more perfect phono-
gram to be produced.
Fig. 43 represents a mouth-piece of mica with a central opening protected at its
edges by a wooden ring.
In Fig. 44, the diaphragm b is of wire gauze with a backing of paper connected
to it by any suitable cement, and there is a ring of stiff paper at the edges of the
gauze disk to strengthen it.
Fig. 45 represents a diaphragm b of parchment or similar material stretched
tightly within the frame by cords and screws. The cords may be of different
lengths and tension, and respond to and reinforce certain sounds.
Fig. 46 shows a mouth-piece for the phouet made in imitation of the human
mouth.
Fig. 47 represents the body portion of the phonograph or phonet made triangular,
and the diaphragm is of corresponding shape.
Fig. 48 represents three cylinders, each provided with a phonograph or phonet ;
this is useful in recording and reproducing three-part singing or music.
Fig. 49 represents a phonet made as a tube, with flaring or trumpet-shaped ends,
and with two diaphragms 15, 16, placed crosswise of the tube so as to form an air
chamber. There is a third diaphragm b, which is vibrated by the movement of the
reproducing point c, and said diaphragm gives motion to the air in the chamber,

page_text: and vibrates the diaphragms 15, 16, which latter produce air waves, and the sounds
issuing from the two trumpet-shaped ends will blend and increase the volume of
sound,
Fig. 50 represents a device whereby deep indentations are made in the metal foil.
Two diaphragms are employed, the first (b) is vibrated by the sound vibrations,
and controls a valve b7 in a tube connected with a source of compressed air or other
fluid; this valve b7 allows more or less air to pass to the diaphragm b, according to
the vibration of the diaphragm 2, hence the diaphragm b will vibrate in harmony
with the diaphragm 62, but it will be acted upon by greater force, and consequently
the indentations will be deeper in the foil than if the diaphragm b was acted upon
simply by the sound vibrations of the voice.
Figs. 51 and 52 represent a device that may be used with a phonet to increase
the loudness of the sounds reproduced. The sound vibrations from the phonet aro
conducted by a tube shown by dotted lines in Fig. 51, to the diaphragm 6s that
controls a valve b' in a tube connected with a reservoir of air or other fluid under
pressure, and the air as it escapes by the valve passes into the trumpet-shaped end
of the tube, and produces sounds that are very loud and clear, and are a repro-
duction of the sounds resulting from the use of one of the phonets before described.
This same apparatus may be used to reproduce with louder utterances a person's
voice, the the sound from the voice being used to vibrate the diaphragm b³, and
thereby regulate the air waves escaping from the valve b' into the trumpet.
Fig. 53 shows the speaker's head within a box or case; in this instance nearly all
the sound vibrations act upon the diaphragm.
Figs. 54 and 55 illustrate how the movements of the lips in speaking may be
recorded and reproduced. In this instance, a lever applied to the diaphragm carries
the indenting point c, Fig. 55, and the end of this lever is placed in the mouth of
the speaker, and the movement of the lips regulates the indentations in the foil.
A similar apparatus shown in Fig. 54 within a case is connected to the movable
lips of a mask, so that these lips open and close as in articulation, at the same time
that the sound vibrations are given by the phonogram to the phonet.
Fig. 56 represents a toy phonet in which the phonogram strip 35 is secured at
one end to a cylinder upon which it is wound. By pulling upon the strip it is
unwound, and a rubber cord 37 is wound upon the shaft of the cylinder. When
the hand is removed from the indented strip, the rubber cord rotates the shaft and
winds up the phonogram upon the cylinder, and the sounds are reproduced in the
phonet by the phonogram acting upon a point and diaphragm a. The movement of
the shaft is regulated by the fau, worm, and pinion 38.
In Fig. 57, the cylinder for moving the phonogram strip is shown as provided
with pins that enter holes in the edges of the strip; this causes the strip to be fed
along very regular.
In Fig. 58, the cylinder with pins is shown as made with heads to act as guides
for the strip.
Fig. 59 shows a re-indenting device for amplifying or increasing the size of the
indentations. There are two rollers, one. of which a' travels faster than the other
a³, and there is a lever 40 pivoted at 41, and provided with a point c for each
cylinder. One point follows the indentations in the cylinder a³, and the other rests
upon a, and as this travels the fastest, the indentations made therein will be longer
and also deeper by the point being at the outer end of the lever.
In Fig. 60, one roller 42 of the pair is made of hardened metal with the sound
record in relief. This is obtained by electrotype or other process from an iron foil
or other metal phonogram, and this roller is used to indent strips or sheets of foil
or rollers to produce copies that can be used with the phonet.
Fig. 61 represents a roller 42 of hardened metal with the record in relief, and
arranged so as to knurl or indent the phonogram in a roller 43 of soft metal that is
to be pressed against the roller 42 by a screw or other suitable means.
The cylinder having a spiral groove in its surface may be made by placing the
mould shown in Fig. 62 around a cylinder or shaft, and filling the space between

page_text: the cylinder and mold with plaster of Paris or other suitable material. The mold is
of metal with a screw or spiral rib projecting therefrom, and it is made in two parts
and hinged so that it can easily be removed when the plaster of Paris is dry.
For amusement or instruction, the phonograph is capable of extended use; for
instance, a revolving cylinder, see Fig. 63, containing rows of indentations repre-
senting the letters of the alphabet, and provided with keys containing corresponding
letters, can be used in teaching the alphabet, and sentences, speeches, and other
matter can be spoken by the phonet, and repeated by the learner without the cyc-
sight being called into usc.
Clocks may be provided with phonogram cylinders or wheels to call off the hours,
to give alarms, &c.
The phonograin may be upon a strip, sheet, belt, or roller, and it can be of a
dog's bark, rooster's crow, a bird's song, a horse's neigh, and these can be used in
toy animals with a simple phonet for reproducing the sound.
In copying phonograms, or making duplicates, an original phonogram may
receive a deposit of copper or iron in a plating bath; and, if of iron, may be car-
bonized to convert it into steel and hardened, and then the same should be backed
up with type metal, and used for impressing strips or pieces of metal.
A bed of gutta percha, or similar material, may be used to sustain the sheet
inetal while being pressed. Numerous copies of the original phonogram can thus be
reproduced.
A plaster cast can be used for producing a copy by pressure.
The governor to regulate the speed of the instrument may be made of a pen-
dulum weight 61, see Fig. 64, hung at the lower end of a rod that is provided
with a universal joint at 62, and the upper end of the rod is moved around by a
crank 63 that is revolved by the train of gearing. As the speed increases the
weight will describe a circle of larger diameter, and thereby increase the
resistance.
The universal joint may be displaced by a spring wire, Fig. 65, that allows of
the movement.
A magnet 64 upon the crank arm 63, Fig. 60, may be used to revolve the pen-
dulum by attracting an armature at the upper end of the pendulum rod, and
thereby avoid the friction resulting from the contact of the surfaces of the pendulum
rod with the crank.
In Fig. 67 the diaphragın bis represented as connected to a pair of delicate
piston valves within a tube 68 that has three ports; onc, 69, is connected to a
reservoir of compressed air, the others, 70 and 71, are connected to a chamber 72
at opposite sides of a diaphragm, so as to vibrate the same in harmony with the
diaphragm b, but there will be greater amplitude given to the same by the pressure
of the air, and by a connection to the phonet diaphragm b² the sound produced will
be greatly increased.
What I claim as my Invention is,―
First. The combination with the diaphragm and point of a flat receiving surface
and means for revolving the receiving surface, and causing the point to follow
a volute or spiral line, substantially as represented in Figs. 1, 2, .6, 7, 8, 9, 10,
and 34.
Second. The combination with the revolving plate phonograph or phonet of a
propelling weight or spring and a governor to regulate the speed, and ensure uni-
formity of movement, substantially as set forth.
Third. A revolving disk provided with a clamping frame to secure the foil or
other material in combination with the swinging arm, diaphragm, and point, sub-
stantially as specified.
Fourth. In a phonograph or phonet, a spring introduced between the diaphragm
and the point, substantially as set forth and shown in Figs. 16, 17, 18, 19, 22,
and 26.
Fifth. In a phonograph or phonet a rubber spring, or similar device, to dampen

page_text: the vibration of the diaphragm, and prevent false vibrations, as set forth and shown
in Figs. 16 and 21.
Sixth. The combination with the diaphragm in a phonograph or phonet apparatus
of a lever to modify the relative action of the diaphragm and point, substantially
as described, and shown in Figs. 17, 18, 27.
Seventh. The combination with the diaphragm and point of a permanent or electro-
magnot, substantially as described, and represented in Figs. 24, 25, 20.
Eighth. The method of recording and reproducing two or more sounds or speeches
simultaneously, substantially as described, and as illustrated by Figs. 28, 29,
and 48.
Ninth. A phonet composed of a perforated sirene and a jet tube, substantially as
described, and represented in Fig. 30.
Tenth. The mechanism for producing a phonograin, and employing the same in a
phonet, substantially as described, and illustrated in Figs. 32, 33, 35, 36, and 37.
Eleventh. The combination with the phonograph, diaphragm, and point of a
sound chamber, substantially as described, and illustrated in Figs. 31, 38, 39,
and 53.
Twelfth. The diaphragm and mouth-pieces for speaking phonograph, substantially
as described, and as illustrated in Figs. 41, 42, 43, 44, 45, and 46.
Thirteenth. The combination with a diaphragm and its point of two diaphragms
for the purposes, and substantially as shown in Fig. 49.
Fourteenth. The combination with a diaphragm and valve actuated by sound
vibrations a source of compressed fluid and a trumpet, as in Figs. 51, 52, or a
phonograph as in Fig. 50, substantially as set forth.
Fifteenth. The combination of two diaphragms with a valve and a source of
compressed fluid, as represented in Fig. 67, for increasing the volume of the voice
or other sound, as set forth.
Sixteenth. The combination with two or more phonograms of phonet keys for
selecting letters or utterances as described, and illustrated in Fig. 63.
Seventeenth. The means for duplicating or reproducing phonograms from an
original phonogram, substantially as set forth.
Eighteenth. The combination with the phonograph or phonet of the revolving
crank and pendulum governor, substantially as described, and shown in Figs.
64, 65, 66.
Nineteenth. The combination with the phonograph of a lover moved by the lips,
and of a lever and phonet to move the lips of a mask, substantially as described,
and illustrated by Figs. 55 and 54.
Twentieth. The combination with a phonogram of a clock movement or toy and
a phonet for reproducing sounds for clocks or toys, substantially as set forth.
In witness whereof, I, the said Thomas Alva Edison, have hereunto set my
hand and seal, this 17th day of September, A.D. 1878.
THOMAS ALVA EDISON. (L.S.)
Witnesses,
CHA³. H. SMITH,
76, Chambers St., New York,
HAROLD SERRELL, 76, Chambers St., New York.