Improvements in or Applicable to Phonographs, and in the Manu- facture and Use of Phonogram-blanks or Surfaces for Receiving the Sound-record.
Year: 1889

page_text: Date of Application, 9th May, 1889
Complete Specification Left, 10th Feb., 1890-Accepted, 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in or Applicable to Phonographs, and in the Manu-
facture and Use of Phonogram-blanks or Surfaces for Receiving
the Sound-record.
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:-
This invention relates to phonographs, and its objects are to simplifythephonograph
and the various accessory devices and render the same more effective and convenient
in operation, and to facilitate the manufacture of and improve the phonogram-blanks
or surfaceswhich receive the record. The present improvements refer tothe recording
points which impress the record, to the reproducing points which are moved by the
record, and to the manner in which such points are supported; to devices for auto-
matically adjusting or determining the position of such points on the recording
surface; to the cutting knives or tools for turning off the old record from a cylin
drical phonogram-blank; to the devices for feeding forward the recorder and the
reproducer to the governor for regulating the speed of rotation of the shaft; to
devices for disposing of the chips or shavings removed from the blank in the operation
of the machine; to the form and construction of the phonogram-blanks, and to
improved methods of making the same and of supporting them upon the cylinder ofs
the machine.
I will first describe the automatic adjusting or determining devices for the recording.
and the reproducing points. As is now well known, the phonograph includes a
spectacle-frame, one eye of which holds the recorder and the other the reproducer.
This frame has two arms (one for each eye) which project forward over a guide-rest,
each arm having a pressor-foot, which bears on the guide-rests and supports the
spectacle-frameas it moves laterallyin definite relation to the surface of thephonogram-
blank. For adjusting the relation of the recording and the reproducing points to the
blank, an adjustable screw passing through each of the arms of the spectacle-frame
and bearing on the guide-rest has heretofore been employed. With such an arrange-
ment it is necessary to adjust the spectacle-fraine relatively to the guide-rest cach
time a new phonogram-blank is placed in the machine, or whenever a portion of
the surface of a blank is removed by cutting. According to the present invention,
devices are provided whereby, each time the spectacle-frame is lowered. its position
relatively to the blank is automatically determined, so that the right adjustment is
obtained with exactness without the exercise of any skill on the part of the operator.
These devices may be made in various ways. but in each of them are employed a
determining point, which strikes the surface of the phonogram-blank as the spectacle-
frame is lowered, and. a lock for holding the parts in the position at which the point
so strikes and which is the position of proper adjustment for the recording point.
In some cases, a fixed determining point is used: the lock being operated by
hand and the determining point then moved away from the blank-surface either
by an independent movement or by the movement necessary to operate the lock, wear
of the said surface being hereby prevented. A movable determining point, such as
one carried by a lever, may, however, be used; the movement of such point due to
its striking the blank-surface having the effect either of locking the presser-foot
directly or of releasing a spring-lock for the purpose.
A construction which has been found particularly convenient is one in which the
determining point is movable and serves to release a spring-lock by its movement,

page_text: The presser-foot is a plate at the lower end of a bar which slides through an arm
extending from the spectacle-frame; such bar being providedwith a spring connected
with the arm and tending to project the presser-foot down to the lowest limit of its
movement. The sliding bar has a longitudinal V-shaped slot into which projects the
tapered end of a locking bolt attached to a pivoted lever having a finger-piece
projecting over the knob on the end of the arm which extends from the spectacle-
frame; the knob being used for lifting such frame. The locking bolt has a spring
for throwing it into engagement with the sliding bar. The determining point is the
end of a bent lever pivoted on the arm of the spectacle-frame; the point being
arranged to strike the surface of the phonogram-blank close to the recording or the
reproducing point and approximately in line laterally therewith. The outer and
upper end of the determining point lever engages with a stud which projects from
the upper end of the locking bolt lever, and is split and provided with an adjusting
screw whereby the point at which the end of the lever is engaged and disengaged by
the stud can be accurately determined. The engagement of the end of the determining
point lever with the stud on the locking lever holds the locking bolt out of engagement
with the sliding bar. The bolt being thus held in a retracted position, if the spectacle-
frame be lifted, the presser-foot is lowered by its spring to its extreme position, and
when the spectacle-frame is again depressed the presser-foot strikes the guide-rest
and the bar slides up against the tension of its spring. Such movement continues
until the determining point reaches the phonogram-surface and then a slight further
movement disengages the end of the determining lever from the stud of the locking
lever and releases the spring-lock the bolt being thereupon projected into engagement
with the sliding bar and serving to lock the presser-foot rigidly in. the position
determined by the determining point. The determining lever is then free, except for
a slight forward spring pressure, so that its point, which is rounded, may ride over
the blank-surface without injuring the same, the said point being wide enough to
extend across a number of the lines of record. By the finger of the locking lever
projecting over the lifting knob, the said finger-is pressed downwardly each time the
spectacle-frame is lifted; the result being that the engagement of the said lever
with the determining lever and the release of the presser-foot are effected on cach
occasion, the parts readjusting themselves when the spectacle-frame is again
lowered.
As is described in the Specification accompanying my previous patent application
No. 12,594, A.D. 1888, the phonograph is provided with a turning or tilting bar
placed in front of the guide-rest to raise the spectacle-frame and the travelling-arm
simultaneously when they are to be retracted. It is obvious that if the tilting bar be
accidentally left in a tilted position so as to engage with the presser-foot before the
latter strikes the guide rest. the adjustment would be performed with relation to the
tilting barinstead of with the guide-rest. To prevent such an occurrence an auxiliary
presser-foot is provided, which forms the lower end of the lever pivoted on and
projecting normally below the main presser-foot and held in position by a spring.
The upper end of the auxiliary lever is furnished with a tooth which engages with a
pin on the side of the projecting arm of the spectacle-frame. When the tilting bar
is in its normal position, the auxiliary lever does not engage with the pin on the
arm; but, if the tilting bar be accidentally left tilted. then the lowering of the
spectacle-frame causes the auxiliary presser-foot to first strike the tilting bar:
the auxiliary lever being thrown to one side. The Looth is thereupon caused to pass
under the pin on the arm so as to prevent the spectacle-frame being lowered any
further. The operator, observing this difficulty, turns the tilting bar, which throws
the auxiliary lever from under the pin, whereupon the main presser-foot strikes the
guide-rest and the proper adjustment is secured. An automatic adjusting device of
of the kind described is mounted upon each of the two arms of the spectacle-
frame, so that the adjustment will be performed for both the recorder and the
reproducer.
In another automatic adjusting device, in which a lock operated by hand is
employed, the pressure-foot is provided with studs or lugs for carrying a sliding rod,

page_text: the end of which forms the determining point. The rod has a projecting part
provided with an inclined edge over which a projection on the spectacle-arm travels
during the movement of the spectacle-frame. The lock consists of a screw-threaded
bolt having a milled head by which it is turned; the bolt working through the
spectacle-arm so as to engage with and lock the sliding rod carrying the presser-
foot. With this arrangement, after the parts are adjusted and locked, the sliding
rod, the point of which forms the determining point, is withdrawn from contact
with the phonogram-surface. A hand-operated lock for locking the sliding bar may
also be used with a determining point carried by a lever pivoted on the spectacle-
frame instead of by a sliding rod; or the determining point. may be a set-screw
mounted directly upon the spectacle-frame.
In a device in which the movement of the determining point directly locks the
presser-foot, the sliding bar is provided with aV-shaped spiral thread which engages
with a locking piece consisting of a plate having a hole with a screw-thread corre-
sponding with that on the sliding bar and through which the said bar passes loosely.
so that the plate forms a clamp for the bar when it is tilted by a rocking arm moved
by the lever which carries the determining point. The arm is connected with the lever
by a frictional connection so that they move in unison until the movement of the arm
is arrested, when the lever moves to a certain extent independently so that it may not
mutilate the phonogram-surface.
A pin may be provided projecting vertically from the presser-foot into a socket on
the arm to prevent the presser-foot from turning on the guide-rest. When the deter-
mining point strikes the phonogram-surface, a slight further movement moves the
rocking arm which tilts the clamp-plate or locking piece and locks the presser-
fool.
In a modification of this arrangement, two parallel screw-threaded sliding bars are
employed carrying the presser-foot, and with their threads adjusted relatively so that
those on one bar are about half the width of a thread above those on the other. The
tiltingclamp-plate or locking piece is providedwith two holes-one for each bar. This
constitutes a more delicate means of adjustment than where only one screw-threaded
bar is used because the clamping plate can always engage instantly with either one or
the other of the screw-threads. The locking piece is sometimes furnished with a
small spring to allow a slight up and down motion. so that it may adjust itself to the
threads. The depth of the locking threads is such that they become locked before the
moving locking piece reaches the bottom of the threads on the bar. This forms a
variable connection which permits the determining point to ride lightly over the
phonogram-surface without injury thereto.
The threads on the two bars may be at the same height as or opposite to each other
if the screw-threads in the two holes in the locking piece are provided with screw-
threads which are approximately one half thread out of position.
In another arrangement there is employed in connection with the determining
point carried by the lever, the guide-rest and the adjustable presser-fooi, a hand-
operated lock and a tripper actuated by a further movement of the lock beyond
that which is necessary to lock the parts for tripping the determining point away
from the phonogram-blank. The determining lever bears on the tripper, in which
there is a depression, and the locking piece has a sliding head connected with the
tripper, so that, when the tripper is moved by the sliding head, the determining lever
drops into the depression; its point being thus raised from the surface of the phono-
gram-blank. Or. instead, thereof, a part connected with the hand-operated locking
piece and capable of independent movement may act directly upon the determining
lever in order to lift the point. away from the blank-surface.
Instead of arranging the tripper to trip the determining point out of contact by
an additional movement of the hand-operated locking piece, the tripper may be
caused to act by such piece during the locking operation. This arrangement consists
of a bar carrying the presser-foot and a screw-threaded stem on the spectacle-frame
enclosing the har and through which such bar is free to slide. The tripper comprises
a lever, a sliding bolt, and a tripping piece formed with a depression into which the

page_text: determining lever drops when the piece is moved by the sliding bolt and tripper-lever
by the downward movement of the screw-threaded stem striking such tripper-lever
after the presser-foot has reached the guide-rest.
In order to relieve the phonogram-surface from the pressure of the determining
point, the latter may be pivoted to the lever or other part which carries it, so that.
when the phonogram revolves, the said point may be tilted and rest lightly on the
phonogram-blank without mutilating it. The point is provided with a spring
to enable it, when the spectacle-frame is raised, to assume its perpendicular
position.
Another part of the invention relates to an improved form of governor for re-
gulating the speed of rotation of the cylinder of the phonograph. The phonograph-
shaft, which carries the cylinder, is rotated by an endless belt from the electric or
other motor: such motor being supported with its shaft in a vertical position.
Another endless beli from the motor-shaft rotates the spindle of the governor
which carries centrifugal governor-balls furnished with springs and arranged to
move a sleeve up and down on the spindle. The sleeve has an extended surface upon
which bears a spring which is included in an electric circuit, and it it also has a disc
on whose under side bears the turned end of another circuit-spring which is
mounted on a flat spring supported on the base of the machine and is adjustable
vertically. As soon as the governor-balls lift the sleeve so that the disc leaves the
spring, the circuit of the motor is broken, a very sensitive regulation of the speed of
the motor being hereby attained,and the use of the electro-magnetheretofore employed
being rendered unnecessary.
The rocking holding arm which carries the swinging spectacle-frame has hitherto
been secured upon the sleeve carrying the traveller-arm a mut on the traveller arm
engaging with the feed-screw and being disengaged therefrom by the striking of a
projection on the sleeve against. a stud on the traveller-arm. This.however, does not
occur until the spectacle-frame is thrown back to nearly the limit of its movement.
In using the phonograph it has been found convenient to raise the spectacle-frame a
short distance and move it along laterally by hand so as to bring the recording or the
reproducing point to a different place upon the phonogram, but such movement
drags the traveller-nut. over the feed-screw, thus wearing that screw out. This
difficulty is now overcome by pivoting upon the side of the traveller-arm à prop-arm
provided with two curved surfaces and a notch which engages with a stud and with
the surface of a cam mounted on the end of the holding sleeve when the spectacle-
frame is lowered and the recording or the reproducing point is in engagement
with the phonogram and the traveller-ant with the feed-screw; but, if the spectacle-
frame be lifted, the sleeve is rotated and turns the cam so that the stud, leaving the
-notch on the prop-arm, tilts the prop-arm into a vertical position, whereupon the said
arm, having its lower end bearing on the base of the machine, lifts the traveller-
arm a sufficient distance to throw the traveller-nni out of engagement with the
feed-screw. Under these circumstances, if the spectacle-frame be moved laterally.the
nut does not wear against the feed-screw and the lower end of the prop-arm slides
along the base. When the spectacle-frame is lowered, the cam is turned and its stud
engages with the notch of the prop-arm and tilts it into an inclined position
and lowers the traveller-arm so that the nut. again engages with the feed-screw:
The vertical shaft of the electric motor which drives the phonograph is mounted on
a jewel-step. The latter has been made of agate, but inasmuch as that jewel
wears rapidly away, sapphire, which is a harder jewel, is now employed. If the
piece of sapphire be large enough, when ground into shape. to fit the cup on the end
of the steel pin which carries the step. the size of the necessary jewel and the cost of
grinding the same into shape makes the use of such a jewel exceedingly expensive.
In order to enable sapphire to be used. without greatly increasing the cost of the
machine, small and irregularly-shaped sapphires, which are not suitable for grinding,
are selected and set in the cup by being imbedded in a suitable cement, such as
oxychloride of zinc or magnesinn, care being taken that the jewel projects at the
centre of the cup above the edges of the same. After the cement has set, the face of

page_text: the jewel at the centre of the cup is. ground and made smooth by holding it
against a suitable. implement. The shaft of the motor only rests on the centre of the
jewel, so that, so long as the centre of the jewel is smooth, it is immaterial
whether it fill the rest of the cup or whether the rest of its surface be smooth or
rough. In this way an inexpensive construction is obtained, cheap jewels being
employed and very little grinding required.
With a phonograph constructed as above desired, any desired recording and
reproducing points may be employed,such for instance as the cutting recording points
and narrow-edged reproducing points described in the specifications to my previous
patent applications No. 17,175. A.D. 1887, and No. 12,593, A.D. 1888. New
recording and reproducing points and new means of arranging and supporting
such points and connecting them with the diaphragm have however, been devised.
The new recording point is one with a curved cutting edge; that is, one whose cutting
edge is an arc of a circle the centre of which is outside the surface. of the
phonogram-blank. An edge of such a shape produces in operation indentations
which are circular in form and have curved sides sloping towards the centre of the
depression. In connection with a record of this kind, a reproducing point is used
which has a curved or rounded bearing surface; that is, a bearing surface which is
a section of a sphere. In practice, a recording point is employed which has a com-
plete circular edge, only a portion of which engages with the surface of the
phonogram-blank at any one time; the point being turned when a portion of its
edge becomes worn or dull, so as to bring a fresh portion into action. Extending
from the cutting edge of the recording point is a narrow stem or shank which enters
a sleeve and is held therein in such a way that it may be readily detached therefrom.
The stem or shank. may be held either by a mechanical device or by cement of.a
kind which can be readily softened by heat. Thus the recording point may easily be
turned in the sleeve or removed therefrom and replaced without the exercise of any
special skill or any delicate adjustment being requisite. The sleeve is held by a lever
of the usual kind attached to the diaphragm or connected therewith in any suitable
way. Furthermore, in practice a reproducing point resembling a ball or sphere
and having a stem or shank removably held in a sleeve in the same way as the
recording point is employed. The reproducing point has a weight, bearing on it and
is so pivoted as to be capable of a slight lateral rocking movement. Each indentation
of the curved cutting edge forming the record of a sound-wave contains the
method not only at the bottom of the indentation but on its curved sides as well:
so that it is immaterial whether the reproducer stand straight in the indentation and
touch the bottom thereof or rock over laterally and touch the sides. This in an
important advantage, because it enables the reproducing lever to be slightly out of
line with the record. Moreover, where straight-sided reproducing and recording
points are used, if the reproducing point be at all inclined, it touches the sides of the
depression and so does not reproduce accurately.but cuts and scrapes against the sides,
this producing sounds foreign to the record besides injuring the same.
Another part of the invention relates to the turning-off tools for removing the old
record from the surface of a cylindrical phonogram-blank and making a new surface
for receiving another record. One form of cutting knife has an oblique cutting point
which is curved to conform to the curvature of the cylindrical phonogram-surface:
that is, curved in the opposite way to the reproducing point just described. By giving
it this form and placing it obliquely to the line of record, the knife cuts a wide chip
which results in a smooth surface.
Another improved form of cutting knife for turning-off tools is one having a
straight cutting edge and a bevelled portion extending therefrom at an angle. The
cutting is done by the straight edge, the bevelled portion resting on the uncut part of
the cylinder and preventing the cutting edge entering the cylinder too deeply, so that
the knife can only cut a thin shaving just deep enough to entirely remove the previous
record. Another way of producing the same result is to use a cutting knife with its
edge forming a right-angle or an angle approximate thereto, so that the face of the
tool may prevent the edge from entering too deeply or breaking the material

page_text: below the part which is being cut away. For turning off the surface of a
phonogram-blank it has been found a tool made of steel cannot be depended upon
for retaining its cutting edge, so à jewel is now employed, such as sapphire, which
holds its cutting edge and produces a very fine smooth surface. The jewel point is
secured by a suitable clamp to the stock of the tool.
In the use of, cutting, tools or knives for turning off the surface of the blanks
difficulty has arisen from the chips or shavings removed thereby. The chips.
especially where a hard brittle material is used for the recording surface, become
electrified and adhere to the surface of the blank and so interfere with the action of
the recorder. They also adhere to the recording points and to other parts of the
machine. When it is attempted to brush or blow them away from the blank they
fly in all directions and cover the machine and neighbouring objects. One way of
avoiding these inconveniences is.to apply to the surface of the phonogram-blank.
before using the turning-off tool, a solution which slightly dissolves the material of
the blank or otherwise acts thereon so as to make its surface comparatively soft and
tough instead of hard and brittle. Under such circumstances, the turning-off tool
makes a continuous shaving which has little or no electrification or in which the
electrification is overcome by gravity, so that the shaving falls into the receptacle
provided therefor and leaves the surface of the blank clean for the action of the
recording point. The substance employed to act on the surface of the blank depends
of course upon the composition of the blank. For a blank composed of a hard
metallic soap a solution of an alkali, such as caustic soda, may be employed; or,
water alone may be used, inasmuch as such blanks seem to be slightly soluble.
Instead of dissolving the surface of the blank, a tough film may be produced thereon
and would answer the same end. For this purpose, a solution of glue and water or
of gum balata and bi-sulphide of carbon, besides many other solutions, may be used.
To further guard against the scattering of the chips or shavings, the phonogram-
blank is enclosed as completely as possible in a protecting cover which encloses its
entire upper half with the exception of an opening on the front side through which
the recording and reproducing points act on the blank. At one end the cover
is secured to the base of the phonograph, its other end being provided with a closing
plate secured to the swinging arm which carries the phonograph-shaft, so that the
phonogram-blank may be removed and replaced.
Another way of preventing the electrification of the chips is to provide the
turning-off tool with a shoulder or projection extending over its cutting edge so
that, as the chips or shavings rise from the cutting edge. they strike against the
shoulder. The material being brittle, the effect is to pound or break the chips into
small particles which fall into the receptacle. Or, a conveying chute may be used
consisting of a box carried in such a position that its upper end is immediately in
front of and in close proximity to the edge of the cutting tool. The chute has a
narrow opening above which its edge overhangs the edge of the cutting tool, so that
the chip or shavings is projected into the chute and conveyed by gravity into a
receptacle at the lower end thereof. The shaving after striking the upper edge of the
chute is broken up into small particles in the same way as with the proprojecting
shoulder above described.
Another part of this invention relates to the phonogram-blanks or surfaces upon
which the sound-record is made. Such blanks are generally in the form of a cylinder
having a taper bore and a true cylindrical outer surface. The latter is of a
material adapted to receive the impressions of the recording point, such material
being placed on a base or backing of a cheaper or more durable substance. This
backing or base may be made by winding cord, thread or the like upon a form and
then covering it with the recording material, so that the base or backing is the
closely-wound body of thread or cord, which must evidently be true and free from
irregularities in shape, and can, therefore, be readily placed upon and removed from
the taper cylinder of the phonograph.
When the outer recording material is one which is comparatively soft and pliable
at ordinary temperatures, such as a soft wax, a backing of cord or even one of paper

page_text: or the like may be readily used; but it has been found better for the purpose of
recording and reproducing sounds to employ as the recording material one which is
hard and brittle at ordinary temperatures. When such a material is employed,
difficulty may arise under extreme changes of temperature because owing to lack of
pliability the outer surface cannot accommodate itself to the expansions and con-
tractions of the backing or lining and is consequently liable to become cracked or
broken. To obviate this, the two parts of the cylinder, that is, the inner part or
backing and the outer part or recording surface, are constructed of substances which
expand and contract under changes of temperature to the same or practically the
same extent. When, for the sound-recording surface, a thin coating of a metallic
soap, such as a stearate of soda, is used, the backing may be of an asphaltic or
bituminous substance, such as one of the natural asphalts or the residues which
are produced artificially. The best results have been produced by the use of Syrian
asphalt, but this is more expensive than some other kinds, and, therefore, it is
preferred to employ asphalt pitch, which is ordinary Trinidad asphalt from which
the more volatile substances have been distilled, and which is a cheap substance. A
small amount of carnauba wax or some other material which contracts greatly in
solidifying is mixed therewith and causes the same to easily leave the mould. To
asphalts which are too thick to pour readily even at high temperatures a little wax of
low melting point, such as Japan wax, may be added; or, instead of the wax,, a
liquid, such as crude petroleum, or turpentine, may be used. In making the
phonogram-blanks the asphalt or the mixture thereof is moulded with other material
into a cylinder having a taper bore; the cylinder, after it has cooled, being dipped
into melted sound-recording material. The sound-recording material may also be
applied by moulding. The asphalt body instead of being moulded may be formed by
pressure from powdered asphalt; or, the cylinders may be formed in a squirting
press in a similar way to that employed in the manufacture of lead pipe.
1
Another good material for forming the backing and having about the same
coefficient of expansion as the metallic soaps (such as stearate of soda) used as the
recording material is hard rubber or ebonite, cylinders of which may be made in the
usual manner of making articles of hard rubber. If it be desired to vary the
rate of expansion of the stearate in order to make it conform to those of different
qualities of rubber, a suitable quantity of an oleate of a metal may be mixed with
the stearate. For instance, if the sound-recording material employed be mono-
stearate of soda, its rate of expansion may be increased by adding a small quantity
of oleate of alumina.
The phonogram-cylinders so far described are of a stiff inflexible nainre. The object
of a part of this invention is to make phonogram-blanks which are flexible, and which
may be conveniently packed and enclosed in envelopes for transmission by mail or
otherwise. For this purpose, thin flexible sheets of wax or wax-like material arc
employed, such sheets being used, either by themselves or combined with backings of
other material, as the recording surfaces. To make these sheets, the material may be
rolled or pressed into shape, but it is found best to make them by forcing the material
through an aperture of the right form in a press. The sheets thus formed may be
used in a variety of ways. They may themselves form flat recording surfaces for the
phonograph, or they may be attached to sheets of paper or other flexible material and
so used, or they may be formed into cylinders either with or without an internal
backing of paper or like material. They may also, if desired, be placed upon rigid
cylinders or backings. Many different compounds of wax or wax-like material may
be employed for this purpose. A mixture of asphalt with Japan wax or other material
for increasing its flexibility has been found most useful. The asphalt alone is brittle,
even in thin sheets, but its flexibility may be increased to any desired degree by
adding less or more of the Japan wax or other substance for imparting flexibility.
To make cylinders from sheets formed by the squirting press or otherwise, the sheet
may be bent round a forming cylinder and the ends pressed together or the ends
may meet and be joined by heat. Or, a sheet of thin paper may be formed into a
cylinder with its edges joined, the cylinder being then collapsed into a flat double
****

page_text: gum
sheet. The double sheet is then placed between two sheets of the flexible wax-like
material and the whole submitted to pressure, the sheets being thus made to adhere
firmly to the paper, whereby a collapsed phonogram-blank is formed which may be
distended into a cylinder for use. Instead of a backing of paper, the thin flexible
sheets may be covered with a varnish, such as a solution of a suitable gum, like
balata, in a solvent such as bi-sulphide of carbon. A number of sheets of this
character may be formed into a composite cylinder from which one layer after another
may be torn as they are used. Cylinders may be formed directly by the action of a
press if the apertures of the press be of annular shape so that the material when forced
out may assume the form of a cylinder.
It is difficult to place thin flexible sheets of the kind just described on the taper
cylinder with which the phonograph is constructed. To enable such sheets to be
readily used on the phonograph, a false shell is provided which has a taper bore and
a cylindrical outer surface so that it may fit on the cylinder of the phonograph and
readily receive the flexible sheet; devices for holding the sheet in position
being added. One way of accomplishing this is to furnish the false shell with numerous
fine sharp points which enter the flexible sheet without penetrating entirely there-
through, the sheet being thus firmly held. The false shell is also made with a raised
flange which serves as a straight guiding edge when the sheet is being bent round
the shell. The false shell may be made in two parts hinged together, their meeting
edges having projecting pins and perforations, the pins on one edge entering the
perforations on the other. In this case, the phonogram-blank should have small
perforations at its ends, the flexible indenting material being omitted at these parts.
The flexible sheet is readily placed on the open hinged shell and is held by the pins
entering the holes in the sheet. The shell is then closed round the phonograph-
cylinder, which it is made to fit, and locked by a suitable catch provided for the
purpose; the phonogram-blank being thereupon in position for operation.
Koh day of AL... 1200
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C.; Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or Applicable to Phonographs, and in the Manu-
facture and Use of Phonogram-blanks or Surfaces for Receiving
the Sound-record.
1, 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:-
This invention relates to phonographs,and its objects are to simplify the phonograph
and the various accessory devices and render the same more effective and convenient
in operation, and to facilitate the manufacture of and improve the phonogram-blanks
or surfaces which receive the record. The present improvements refer to the recording
points which impress the record, to the reproducing points which are moved by the
record, and to the manner in which such points are supported; to devices for auto-
matically adjusting or determining the position of such points on the recording
surface to the cutting knives or tools for turning off the old record from a cylindrical
phonogram-blank; to the devices for feeding forward the recorder and the reproducer;
to the governor for regulating the speed of rotation of the shaft to devices for
disposing of the chips or shavings removed from the blank in the operation of the
machine to the form and construction of the phonogram-blanks, and to improved
methods of making the same, and of supporting them upon the cylinder of the
machine.
:
..

page_text: In the accompanying drawings, Fig. 1 represents partly in section and partly in
side elevation a phonograph constructed according to the present invention; Fig. 2
being a corresponding plan. Figs. 3 and 4 are views shewing in different positions
the device for disengaging the traveller nut. Fig. 5 is an end elevation corresponding
with Figs. 1 and 2. Fig. 6 is a plan of the spectacle-frame (one of its arms being in
section) shewing the spring-lock for the presser-foot. Fig. 7 represents one side of
one of the arms of the spectacle-frame; Fig. 8 displaying the other side of such arm.
These two views serve to illustrate the automatic determining and locking devices.
Fig. 9 explains the action of one of the locking devices. Fig. 10 is a plan of the
presser-foot with the auxiliary presser-foot attached thereto. Fig. 11 is a perspective
view of the cutting knife. Fig. 12 is a side elevation of another form of automatic
adjusting or determining device shewing the determining point in contact with the
phonogram-blank and the spectacle-frame locked in the position determined by the
determining point. Fig. 13 is a similar view; the determining point being, however,
out of contact with the phonogram-blank. Figs. 14 and 16 are side elevations
shewing two modifications of the construction illustrated in Figs. 12 and 13. Fig. 15
is a plan of the device shewn in Fig. 14 for withdrawing the determining point from
the phonogram; such device being also applicable to the construction represented in.
Fig. 16. Fig. 7 is a side elevation of a determining device in which the determining
point locks the presser-foot directly. Fig. 18 is a corresponding plan. Figs. 19
and 20 are respectively a side elevation and a plan of a modified form of the device
shewn in Figs. 17 and 18. Figs. 21 and 22 being a side elevation and a plan of the
locking piece. Fig. 23 is an enlarged section on the line 7-7 in Fig. 20. Fig. 24
is a side elevation of a device in which the determining point is moved away from
the surface of the wax by an independent. movement of a hand-operated lock; the
determining point being shewn in contact with the phonogram-blank and ready to be
withdrawn by the locking mechanism. Fig. 25 is a corresponding plan. Fig. 26
shews in side elevation a modified form of construction. Fig. 27 is a plan corre-.
sponding with Fig. 26; the spectacle-frame being, however, omitted. Fig. 28 is an
end elevation shewing the mode of connecting the locking nut to the locking piece.
Figs. 29 and 30 illustrate a further modification of the device represented in Figs. 24
and 25. Fig. 31 is a side elevation of a device in which the hand-locking movement
operates a tripper to trip the determining point away from the phonogram-blank; the
determining point being shewn in contact with the blank, and the locking mechanism
and tripper ready to be operated to lock the parts and withdraw the deterinining
point. Fig. 32 is a plan on the line 2-2 in Fig. 31. In Fig. 3, the parts are
locked the determining point being withdrawn. Fig. 34 is a side elevation of a
device in which the determining point is pivoted to and carried by a lever attached to
the spectacle-frame. Figs. 35 and 36 are respectively an end and a side elevation of
the governor. Fig. 37 is an enlarged detail-view explaining the construction of the
improved jewel step for the vertical shaft of the electric driving motor. Fig. 38 is a
diagrammatic view partly in section and partly in elevation slewing the case and
mouth piece of the recorder, and a new form of recording point. Fig. 39 is a longi-
tudinal vertical section through the recording point and the holder in which it is
mounted. Fig. 40 is a view illustrating in perspective the holder and the lever
which carries it. Fig. 41 shews in perspective a modified form of recording point.
Fig. 42 is a diagrammatic view of the reproducer: Fig. 43 being a corresponding
plan. Fig. 44 represents partly in side elevation and partly in section the reproducing
point and the parts by which it is supported. Fig. 45 shews a modified form of
reproducing point. Fig. 46 is a diagrammatic plan of the record produced by the
new form of recording point. Fig. 47 is a plan of the spectacle-frame shewing the
new turning-off tool or knife mounted thereon. Fig. 48 is a side elevation of such
turning-off tool or knife detached. Figs. 49 and 50 are diagrams explaining the
difference between the action of the new and of the old turning-off tool. Fig. 51 is
an end elevation of a portion of the phonograph shewing the cylindrical phonogram-
blank. Fig. 52 is a vertical section through the recorder: Fig. 53 being a corre-
sponding plan. Fig. 54 is a diagram shewing the position of the turning-off tool.

page_text: Fig. 55 represents the bottom of the conveying chute. Fig. 56 is a plan of the
spectacle-frame displaying the cutting knife with the breaking shoe attached for the
chips or shavings to strike against as they fly from the blank. Figs. 57 and 58 are
respectively a side and an end view of the cutting knife. Fig. 59 is a perspective
view of a machine for winding the cord or thread used in some instances for making
the lining or backing of the phonogram-blank. Fig. 60 is a vertical section of the
mould used for applying the sound-recording material to the lining or backing so
produced Figs. 61 and 62 being corresponding plan views. Fig. 63 is a longi-
tudinal section through a completed cylinder. Figs. 64 and 65 are a longitudinal
and a transverse section of a new phonogram-blank. Fig. 66 is a vertical section of
a squirting press adapted for the production of thin sheets of wax or wax-like
material for use in the manufacture of flexible phonogram-blanks. Fig. 67 is a plan
of the bottom of the press; Fig. 68 being a similar view shewing a modification.
Fig. 69 is a diagram illustrating the manner in which it is preferred to place the thin
sheets of wax or wax-like material upon a paper backing. Fig. 70 is an end elevation
of a completed cylinder. Fig. 1 represents in perspective a cylinder formed from a
thin sheet of wax or wax-like material without a paper backing. Fig. 72 is an end
elevation of a cylinder made up of several sheets, which are intended to be torn off
one by one as used. Fig. 73 is a side elevation representing a false shell for a
phonogram-blank in position on the phonogram-cylinder. In Fig. 74, a phonogram-
blank is shewn on the false shell; the blank and shell being in section. Fig. 75 is a
perspective view of a flexible phonogram-blank before it is placed on the false shell.
Fig. 76 being an end view of the phonogram-blank in position on the false shell
on the phonogram-cylinder. In Fig. 77, another kind of false shell is shown; the
shell being open. Fig. 78 is a perspective view of a phonogram-blank such as is
used with this kind of shell. Fig. 79 is an end elevation of the phonogram-cylinder,
the shell, which is closed, and the phonogram-blank. In Fig. 80, the shell carrying
the phonogram-blank is open.
1 will first describe the automatic adjusting or determining devices for the
recording and the reproducing points. As is now well known, the phonograph
includes a spectacle-frame, one eye of which holds the recorder and the other the
reproducer. This frame has two arms (one for each eye) which project forward over
a guide-rest, each arm having a presser-foot, which bears on the guide-rest and
supports the spectacle-frame as it moves laterally in a definite relation to the surface
of the phonogram-blank. For adjusting the relation of the recording and the
reproducing points to the blank, an adjustable screw passing through each of the
arms of the spectacle-frame and bearingon theguide-rest has heretofore been employed.
With such an arrangement it is necessary to adjust the spectacle-frame relatively
to the guide-rest each time a new phonogram-blank is placed in the machine,or when
ever a portion of the surface of the blank is removed by cutting. According to the
present invention, devices are provided whereby, each time the spectacle-frame is
lowered, its position relatively to the blank is automatically determined, so that the
right adjustment is obtained with exactness without the exercise of any skill on the
part of the operator. These devices may be made in various ways, but in each of
them are employed a determining point, which strikes the surface of the phonogram-
blank as the spectacle-frame is lowered, and a lock for holding the parts in the
position at which the point so strikes, and which is the position of proper adjustment
for the recording point. In some cases, a fixed determining point is used: the lock
being operated by hand and the determining point then moved away from the
surface of the blank either by an independent movement or by the movement
necessary to operate the lock; wear of the said surface being hereby prevented. A
movable determining point, such as one carried by a lever, may, however, be used;
the movement of such point due to its striking the surface of the blank having the
effect either of locking the presser-foot directly or of releasing a spring-lock for
the purpose.
A (Figs. 1.2.5 and 6) is the spectacle-frame. B is the driving motor. C is the
phonograph-shaft carrying the phonogram-cylinder C and provided with a fine

page_text: feeding screw-thread c. The phonograph-shaft is rotated by an endles belt C² from
the motor B. Another endless belt D2 from the vertical shaft of the motor
rolates the spindle D' (Fig. 13) of the governor D. E (Figs. 2, 3 and 4) is the
traveller-arm. F (Fig. 11) is the cutting knife. G is the protecting cover, and G¹
the closing plate.
A construction which has been found particularly convenient is one in which the
determining point is movable and serves to release a spring-lock by its movement.
The presser-foot a (Figs 7 and 9) is a plate at the lower end of a bar a' which slides
through an arm A¹ or A² extending from the spectacle-frame A; such bar being
provided with a spring a connected with the arm and tending to project the presser-
foot down to the lowest limit of its movement. The sliding bar a' has a longitudinal
V-shaped slot into which projects the tapered end of a locking boli attached to
a pivoted lever a having a finger-piece a projecting over the knob a on the end of
the arm A the knob being used for lifting the spectacle-frame. The locking bolt a
has a spring (Fig. 6) for throwing it into engagement with the sliding bar a'.
The determining point (Fig. 5) is the end of a bent lever a pivoted on the arm of
the spectacle-frame; the point being arranged to strike the surface of the phonogram-
blank close to the recording or the reproducing point and approximately in line
laterally therewith. The outer and upper end of the determining point lever engages
with a stud a", which projects from the upper end of the locking bolt lever, and is
split and provided with an adjusting screw a whereby the point at which the end of
the lever is engaged and disengaged by the stud can be accurately determined. The
engagement of the end of the lever a with the stud on the locking lever a holds
the locking bolt a out of engagement with the sliding bar a'. The bolt being
thus held in a retracted position, if the spectacle-frame A be lifted, the presser-foot a
is lowered by its spring a² to its extreme position; and, when the spectacle-frame is
again depressed, the presser-foot strikes the guide-rest a", and the bar a' slides up
against the tension of its spring. Such movement continues until the determining
point a reaches the surface of the phonogram-blank, and then a slight further
movement disengages the end of the lever from the stud a", and releases the.
spring-lock, the bolt being thereupon projected-into engagement with the sliding
bar and serving to lock the presser-foot a rigidly in the position determined by
the determining point . The lever is then free, except for a slight forward
spring pressure, so that its point a", which is rounded, may ride over the surface of
the blank without injuring the same; the said point being wide enough to extend
across a number of the lines of record. On account of the finger af of the locking
lever projecting over the lifting knob a, the said finger is pressed downwardly
cach time the spectacle-frame A is lifted; the result being that the engagement of
the lever with the lever and the release of the presser-foot a are effected on
each occasion; the parts readjusting themselves when the spectacle-frame is again
lowered.
As is described by me in the Specification to Letters Patent No. 12,594, A.D. 1888.
the phonograph is provided with a turning or tilting bar A" placed in front of the
guide-rest to raise the spectacle-frame A and the traveller-arm E simultaneously
when they are to be retracted. It is obvious that if the tilting bar A" be accidentally
left in a tilted position so as to engage with the presser-foot a before the latter strikes
the guide-rest", the adjustment would be performed with relation to the tilting
bar A instead of with relation to the guide-resta". To prevent such an occurrence,
an auxiliary presser-foot a (Figs. 7 and 9) is provided, which forms the lower end
of a lever a pivoted on and projecting normally below the main presser-foot aand
held in position by a spring a". The upper end of the lever is furnished with a
tooth a which engages with a pin on the side of the projecting arm of the
spectacle-frame. When the tilting bar A is in its normal position, the auxiliary
presser-foot a does not strike against it, and the lever a does not engage with the
pin on the arm; but, if the tilting bar be accidentally left tilted, then the lowering
of the spectacle-frame A causes the auxiliary presser-foot a to first strike the tilting
bar A the auxiliary lever a being thrown to one side. The tooth is thereupon

page_text: caused to pass under the pin as, so as to prevent the spectacle-frame being lowered
any further. The operator, observing this difficulty, turns the tilting bar, which
enables the spring to throw the auxiliary lever from under the pin a, and
against the pin a, whereupon the main-presser-foot a strikes the guide-rest ", and
the proper adjustment is secured. An automatic adjusting device of the kind described
is mounted upon each of the two arms A' and A2 of the spectacle-frame, so that
adjustment may be effected for both the recorder and the reproducer.
In another automatic adjusting device. illustrated in Figs. 12 to 16. in which a
lock operated by hand is employed, the presser-foot a is provided with studs or
lugs for carrying a sliding rod a", the end of which forms the determining
point. The presser-foot is kept in position by a pin a parallel with a bar a*. The
rod has a projecting part provided with an inclined edge over which a projection
on the arm A travels during the movement of the spectacle-frame. The lock consists
of a screw-threaded bolt having a milled head by which it is turned; the bolt a¹
working through the arm A' so as to engage with and, lock the sliding rod a¹*.
With this arrangement, after the parts are adjusted and locked, the sliding rod a".
the point of which forms the determining point, is withdrawn from contact with
the surface of the phonogram-blank H. When the presser-foot a, being in its lowest.
position with respect to the arm A, comes in contact with the guide-rest a", its
further movement is arrested, and the spectacle-frame descends by gravity against
the tension of the spring *. As the spectacle-frame thus descends, the projection
on the arm A, by contact with the incline on the part a. forces forward the deter-
mining point * until it comes against the surface of the phonogram-blank H: the
operator thereupon turning the locking bolt 21 to prevent the further descent of the
spectacle-frame. Or, the bar " may be pushed out so that its point may be in
contact with the phonogram-blank as the spectacle-frame is lowered: the descending
movement. being arrested when the part 2 touches the projection on the arm A'.
The operator then turns the bolt. The exact position the recording or the
reproducing point is to bear in relation to the phonogram-blank having been thus
determined, the determining point may be removed from contact with the phonogram-
blank by turning the bar until the projection on the arm A' is out of the path
of the part and then withdrawing the bar as indicated in Fig. 18. In Fig. 14.
the determining point is carried by a lever pivoted at to the arm A on
the spectacle-frame. After the spectacle-frame has been locked in the determined
position, the determining point. may be withdrawn by turning the screw a².
The latter is preferably connected to the lever 2, and provided with a head a
having a projecting arm (2. A stop-screw is mounted in a ing (see Fig. 15) on
the spectacle-frame. The movement necessary for withdrawing the determining
point from the surface of the phonogram-blank, or for returning it thereto. is
controlled by the contact of the arm with the screw 7. In Fig. 16, the deter-
mining point is mounted directly on the spectacle-frame and forms part of the
screw. The point a* is withdrawn by rotating the screws of which it forms part.
The collar acts as a controlling stop: though an arrangement similar to that
illustrated in Figs. 14 and 15 may be employed, if preferred.
.30
In a device, such as illustrated in Figs. 17 and 18. in which the movement of the
determining point a* directly locks the presser-foot a. the sliding bar a* is formed
with a V-shaped screw-thread adapted to engage with a locking piece consisting of a
plate pivoted to the arm A¹ and having a hole formed with a screw-thread
corresponding with that on the sliding bar. The bar a passes loosely through the
hole in the plaie . The plate when tilted forms a clamp for the bar. A rocking
arm a moved by the lever, which carries the determining point serves to tili
the locking plate. The lever is mounted on a sleeve which is free to rotate
on a set-screw a projecting from the side of the arm A. The rocking arm is
also mounted on the sleeve, a friction-disc of leather or other suitable material
being placed between the arm and the lever . The object of the friction-
device is to enable the arm and lever to move in unison until the movement of the
arm is arrested, when the lever moves to a certain extent independently, so that it

page_text: may not mutilate the surface of the phonogram. The spring for lowering the
presser-foot is of the kind previously illustrated, and is omitted in these figures. A
set-screw prevents the lever a, falling too far. The spectacle-frame is raised and.
lowered by the noba". By manipulating the finger-piece on the end of the
lever the locking mechanism can be thrown out of engagement. The action of
the parts is as follows:As the spectacle-frame is lowered, the presser-foot a strikes
the guide-rest a", and the bara slides upwards against the tension of its spring
until the determining point reaches the surface of the phonogram-blank H. The
further depression of the spectacle-frame canses the sleeve a to rotate, thereby
lifting the arm upwards against the locking plate ", which thereupon engages
with the sliding bar a and locks the presser-foot in the position thus determined
by the determining point. The lever is still, however, by reason of the friction-
device, capable of yielding to permit the determining point to ride over the surface of
the phonogram-blank without injury thereto.
"
100
In a modification of this arrangement, shown in Figs. 19 to 28, two parallel screw-
threaded sliding bars are employed to carry the presser-foot a. Their threads
are so adjusted in relation in one another (as indicated by the dotted line - in
Fig. 23) that the thread on one bar is about half the width of the thread above that
on the other bar. The tilting clamp-plate or locking piece is provided with iwo
semicircular screw-threaded recesses-one for each bar; the threads being on the
same level. The locking piece is operated by the short arm * of the lever . The
pin is dispensed with. This constitutes a more delicate means of adjustment
than where only one screw-threaded bar is used, because the clamping plate can
always engage instantly with either one or the other of the screw-threads. The
locking piece is sometimes furnished with a small spring to allow a slight up and
down motion, so that it may adjust itself to the threads. The depth of the locking
threads is such that they become locked before the moving locking piece reaches
the bottom of the threads on the bar. This allows sufficient play to permit the
determining point a* to ride lightly over the surface of the phonogram without
injury thereto.
30%
10
330*
*
The threads on the two bars ³ ³ may be at the same height as or opposite to
each other if the two holes in the locking piece are provided with screw-threads
which are approximately one half thread out of position with respect to each other.
In Figs. 24 and 25, there is employed in connection with a determining point *
carried by a lever having two arms and the guide-rest " and the adjustable
presser-fool a, a hand-operated lock a" and a tripper a actuated by a further
movement of the lock beyond that which is necessary to lock the paris for tripping
the determining point a* away from the phonogram-blank H. The short arm a*** of
the determining lever is heavier than the long arm, and bears on the tripper a½.
in which there is a depression * The locking piece has a siiding head
connected with the tripper aby the link so that, when the tripper is moved by
the sliding head, the short arm of the determining lever drops to the extent permitted
by the depression the determining point * on the long arm a being thus
raised from the surface of the phonogram-blank. The head is prevented from
rotating independently on the locking piece a by a feather and feather-way or
equivalent means. The movement of the tripper a, which is pivoted to the side of
the arm A is controlled by two pins projecting from the side of the arm. The
short arm of the lever is provided with a set-screw, which bears on the upper
end of the tripper a. The link a engages with a groove in the head *. In
Figs. 26 and 27. a flange on the head engages with a groove in the tripper: the
construction being otherwise substantially the same as in Figs. 24 and 25. Or, a
part connected with the hand-operated locking piece a" and capable of independent.
movement may act directly upon the determining point lever in order to lift the
determining point away from the surface of the blank. Such a construction is
illustrated in Figs. 29 and 30. The locking screw a" and the head by which it is
turned are formed in one piece. The locking is effected by a slide a mounted
axially in the locking screw. The slide is pressed forward by a helical spring a",

page_text: The object of this arrangement is to permit, after the locking of the bar a*, a further
rotation of the locking screw" in order to effect the withdrawal of the determining
point from the phonogram-blank. The set-screw a" in the end of the short arm **
of the determining point lever bears against a set-screw in the arm A, and carries at
its upper extremity an L-shaped lever one arm of which lies normally in the
path of a projecting L-shaped arm " on the head of the locking screw. The
L-shaped lever is kept in the normal position by a spring a. After the bar * has
been locked, the arm arrives in contact with the L-shaped lever and turns the
Screw, this permitting the short arm of the lever to fall, under the influence
of gravity, to a corresponding extent; the determining point a* thereupon receding
from the surface of the phonogram-blank.
arm a
Instead of arranging the tripper to trip the determining point out of contact by an
additional movement of the hand-operated locking piece, the tripper may be caused
to act by such piece during the locking operation. Such an arrangement is illustrated
in Figs. 31 to 33, and comprises a bar a connected, as before, by a spring to the
arm A, and carrying the presser-foot a. The bar slides within a screw-threaded
stem working in the arm A' of the spectacle-frame. The tripper comprises a
lever (having two arms and a) pivoted to the presser-foot a, a sliding bolt a",
and a tripping piece formed with a depression into which the set-screw on the short
10 of the determining point lever drops in order to allow the determining point
to recede from the surface of the phonogram-blank. The parts are locked in the
determined position by rotating the stem a, which thereupon engages with and
depresses the lower arm of the tripper-lever. This causes the arm as to operate
the sliding bolt a by which the stem aforesaid is locked. The bolt a carries two
laterally-projecting pins which play in a slot in the arm A. The tripping piece a
lies between and is actuated by these pins, so that, whilst the parts are being locked.
the depression in the tripping piece is brought under the set-screw carried by the
arm of the determining point lever; the determining point being thereupon
free to leave the surface of the phonogram-blank.
In order to relieve the surface H of the phonogram from the pressure of the
determining point, the latter may be pivoted to the lever or other part which
carries it, as represented in Fig. 34, so that, when the phonogram revolves, the said
point may yield and rest lightly on the phonogram-blank withoni mutilating it.
The pivoted point q* is provided with a spring to enable it, when the spectacle-
frame A is raised, to assume its normal position.
Another part of the invention relates to an improved form of governor, shewn in
Fig. 1, 2, 35 and 36, for regulating the speed of rotation of the cylinder C' of the
phonograph. The spindle D' of the governor D carries centrifugal governor-balls dd
mounted on springs a'd', and arranged to move a sleeve up and down on the
spindle D'. The sleeve has an extended surface upon which always bears a contact-
spring (included in the electric circuit). It also has a disc on whose under side
bears the turned up end of another contact-spring, which is mounted on a flat
spring supported on the base of the machine and adjusted by a nut d§. As soon as
the governor-balls dd lift the sleeve so that the disc leaves the spring d, the
electric circuit of the motor is broken: a very sensitive regulation of the speed of the
motor (the circuit being only broken at one point) being hereby attained. The use of
the electro-magnet heretofore employed is rendered unnecessary. The improved
governor may be connected directly with the armature of the motor.
The rocking holding arm A*, which carries the swinging spectacle-frame A.
has hitherto been secured upon the sleeve carrying the iraveller-arm E a nut. on
the traveller-arm engaging with the feed-screw e and being disengaged therefrom
by the striking of a projection on the sleeve against a stud on the traveller-arın
This, however, does not occur until the spectacle-frame A is thrown back to nearly
the limit of its movement. In using the phonograph, it has been found convenient.
to raise the spectacle-frame a short distance and move it along laterally by hand,
so as to bring the recording or the reproducing point to a different place upon
the phonogram, but such movement drags the traveller-nut over the feed-surew e

page_text: thus wearing that screw out. This difficulty is now overcome by pivoting upon
the side of the traveller-arm E a prop-arm E' provided with two curved surfaces
and a notch e which engages with a stud e and with the surface of a cam e
mounted on the end of the holding sleeve when the spectacle-frame is lowered
and the recording or the reproducing point is in engagement with the phonogram
and the traveller-nut with the feed-screw ; but, if the spectacle-frame be lifted,
the sleeve is rotated and turns the cam e so that the stud e', leaving the notch e
in the prop-arm E, tilts the prop-arm into a vertical or nearly vertical position,
whereupon the said arm, having its lower end bearing on the base of the machine,
supports the traveller-arm E at a sufficient height to throw the traveller-mut out
of engagement with the feed-screw c. Under these circumstances, if the spectacle-
frame be moved laterally, the traveller-nut does not wear against the feed-screw,
and the lower end of the prop-arm slides along the base. When the spectacle-
frame is lowered, the cam e² is turned and its stud e' engages with the notch e
and tilts the prop-arm into an inclined position; the traveller-arm being thereupon
lowered so that the traveller-nut again engages with the feed-screw c.
The vertical shaft B' of the electric motor Bwhich drives the phonograph is mounted
on a jewel step. The latter has hitherto been made of agate, but inasmuch as that
jewel wears rapidly away, sapphire, which is a harder jewel, is now employed. If the
piece of sapphire be large enough, when ground into shape, to fit the cup in the end
of the steel pin which carries it, the size of the jewel and the cost of grinding the
same into shape makes the use of such a jewel exceedingly expensive. In order to
enable sapphire to be used without greatly increasing the cost of the machine, small
and irregularly-shaped sapphires, which are not suitable for grinding, are selected and
set in the cup by beingimbedded in a suitable cement 62 (Fig. 37), such as oxychloride-
of zinc or magnesium; care being taken that the jewel projects at the centre of the cup
above the edges of the same. After the cement has set, the face of the jewel at the
centre of the cup is ground andmade smooth by holding it against a suitable grinding
surface. The shaft B' is pointed and only rests on the centre of the jewel, so that
as long as the centre of the jewel is smooth, it is immaterial whether the
remainder of the face of the jewel be smooth or rough. In this way, an inexpensive
construction is obtained; cheap jewels being employed and very little grinding
required.
With a phonograph constructed as above described, any desired recording and
reproducing points may be employed, such for instance as the cutting recording
points and narrow-edged reproducing points described by me in the specifications to
Letters Patent No. 17.175, A.D. 1887, and, No. 12,593, A.D. 1888. New recording
and reproducing points and new means of arranging and supporting such points and
connecting them with the diaphragm have, however, been devised. The new recording
point is one with a curved cutting edge; that is, one whose cutting edge is an arc
of a circle the centre of which is outside the surface of the phonogram-blank. An
edge of such a shape produces in operation a series of indentations each of which is
circular in form and has curved sides, as represented diagrammatically in Fig. 46,
sloping towards the centre of the depression. In connection with a record of this
kind, a reproducing point 1 or 1* is used, which has a curved or rounded bearing
surface; that is, a bearing surface which is a section of a sphere. In practice, à
recording point is employed which has a complete circular edge (see Fig. 39), only a
portion of which engages with the surface of the phonogram-blank at any one time;
the point being turned when a portion of its edge becomes worn or dull, so as to
bring a fresh portion into action. Extending from the cutting head of the recording
point is a narrow stem or shank ' which enters a sleeve and is held therein in such
a way that it may be readily detached therefrom. The stem or shank may be held
either by a mechanical device or by cement of a kind which can be readily softened
by heat. Thus the recording point may easily be turned in the sleeve or removed
therefrom and replaced without the exercise of any special skill or any delicate
adjustment being requisite. The sleeve forms part of a lever of the usual kind
attached to the diaphragm or connected therewith in any suitable way. Furthermore

page_text: in practice a reproducing point or (see Figs. 42 to 44) resembling a ball or
sphere and having a stem or shank removably held in a sleeve in the same way as
the recording point is employed. The reproducing point has a weight bearing on
it, and is so pivoted as to be capable of a slight lateral rocking movement. Each
indentation of the curved cutting edge forming the record of a sound-wave contains
the record not only at the bottom of the indentation but on its curved sides as well, so
that it is immaterial whether the reproducer stand straight in the indentation and
touch the bottom thereof or rock over laterally and touch the sides. This is an
important advantage, because it enables the reproducing lever to be slightly out of line
with the record. Moreover, where straight-sided reproducing and recording points
are used, if the reproducing point be at all inclined, it touches the sides of the
depressionand so does not reproduce accurately, but cuts and scrapes against the sides:
thus producing sounds foreign to the record, besides injuring the same.
Another part of the invention relates to turning-off tools for removing the old record
from the surface of a cylindrical phonogram-blank and making a new surface for
receiving another record. The cutting knife F, shown in Fig. 11, has an oblique cutting
point, which is curved as represented, to conform to the curvature of the surface of
the cylindrical phonogram; that is, curved in the opposite way to the reproducing
point just described. By giving it this form, and placing it obliquely to the line of
record, the knife cuts a wide chip which results in a smooth surface.
In Fig. 54, the cutting knife or turning-off tool F¹ has a straight cutting edge /
and a bevelled portion extending laterally therefrom. The cutting is done by the
edge the bevelled portion resting on the uncut part of the cylinder and
preventing the cutting edge entering the cylinder too deeply, so that the knife can
only cut a thin shaving just deep enough to entirely remove the previous record.
In Figs. 47 and 48, the plane surfaces // constituting the cutting edge of the
knife meets at an angle of ninety degrees or thereabouts, so that the face of the
tool may prevent the edge from entering too deeply or breakingthe material belowthe
part which is being cut away. For turning off the surface of a phonogram-blank, it has
been found a tool made of steel cannot be depended upon for retaining its cutting.
edge, so a jewel is now employed, such as sapphire, which retains its cutting edge
and produces a very fine smooth surface. The jewel is secured by a suitable
clamp to the stock of the tool. The sharp cutting edge of the knife F* (Fig. 50)
enters beneath thesurface of the material; the chips produced carry away with them
portions of the material below the line of cutting. Where an edge made as represented
in Fig. 49 is used, the point of the tool breaks the material away as fast as it is
cut the result being that the chips break off close to the edge of the tool and do
not carry with them any portion of the material, below the line of cutting.
In the use of cutting tools or knives for turning off the surface of the blanks
difficulty has arisen fromthe chips or shavings removed thereby. The chips especially
where a hard brittle material is used for the recording surface, become electrified and
adhere to the surface of the blank, and so interfere with the action of the recorder.
They also adhere to the recording points and to other parts of the machine. When it
is attempted to brush or blow them away from the blank, they fly in all directions
and cover the machine and neighbouring objects. One way of avoiding these
inconveniences is to apply to the surface of the phonogram-blank, before using the
turning-off tool, a solution which slightly dissolves the material of the blank or
otherwise acts thereon so as to make its surface comparativelysoft and tough instead
of hard and brittle. Under such circumstances, the turning-off tool makes a con-
tinuous shaving which has little or no electrification or in which the electrification is
overcome by gravity, so that the shaving falls into the receptacle provided therefore
and leaves the surface of the blank clean for the action of the recording point. The
-substance employed to act on the surface of the blank depends of course upon the
composition of the blank. For a blank composed of a hard metallic soap, a solution
of an alkali, such as caustic soda, may be employed; or. water alone may be used,
inasmuch as such blanks are slightly soluble. Instead of dissolving the surface of the
blank, a tough film may be produced thereon, and would answer the same end. For

page_text: this purpose, a solution of glue and water or of gum balata and bi-sulphide of carbon,
besides many other solutions, may be used. To further guard against the scattering
of the chips or shavings, the phonogram-blank is enclosed as completely as possible in
a protecting cover G. which encloses its upper part, with the exception of an opening
on the front side through which the recording and the reproducing points act on the
blank. At one end, the cover G is secured to the base of the phonograph, its other
end being provided with a closing plate G'secured to the swining arm which carries
the phonograph-shaft, so that the phonogram-blank may be easily removed and
replaced.
Another way of preventing the electrification of the chips is to provide the "
turning-off tool F (Figs. 56 to 58) with a shoulder or projection extending over
its cutting edge so that, as the chips or shavings rise from the cutting edge, they
strike against the shoulder. The latter is held in position by the set-screw /. The
material being brittle. the effect is to pound or break the chips into small particles.
which fall into the receptacle. Or, a conveying chute (Figs. 51 to 53 and 55) may
be used consisting of a box n carried in such a position that its upper end is
immediately in front of and in close proximity to the edge of the cutting tool. The
chute has a narrow opening a', above which its edge overhangs the edge of the
cutting tool, so that thechip or shaving is projected into the chute and conveyed by
gravity into a receptacle at the lower end thereof. The shaving, after striking the
upper edge of the chute, is broken up into small particles in the same way as withthe.
projecting shoulder above described.
Another part of this invention relates to the phonogram-blanks or surfaces upon
which the sound-record is made. Such blanks are generally in the form of a
cylinder having a taper bore and a true cylindrical outer surface. The latter is of a
material adapted to receive the impressions of a recording point, such material being
placed on a base or backing of a cheaper or more durable substance. This backing
or base may be made by winding cord, thread or the like upon a form and then
covering it with the recording material, so that the base or backing is the closely
wound bodyof thread or cord, which must evidentlybe true and free fromirregularities
in shape, and can, therefore, be readily placed upon and removed from the taper
cylinder of the phonograph. The character of the machine employed for winding
the cord or thread to form the backing may be readily gathered on reference to the
diagrammatic view Fig. 59, in which O is a backing in the course of being wound
on a form O'. The form is placed on the end of a shaft 02 mounted to rotate in
suitable bearings attached to a stand 0*. The shaft. Q drives the screw-shaft 0%
The thread o is taken from a bobbin o' on a shaft O' and passes through an eye
in a nut . The latter gradually travels along the shaft O' guiding the thread o
until, when the backing is completed, the projection of arrives in contact with the
spring and closes the electric circuit in which the armature 0 is included: the
effect being to move, through the rod, the driving belt of from the fast to
the loose pulley on the driving shaft 0%, and thus to stop the operationof the machine.
The core or form, with the backing wound thereon, is then placed in a mould P, into
which the wax or other material in a plastic condition is thereupon poured through
the opening p. The air in the mould escapes through the aperture p'. knives p²
and are furnished for separating superfluous wax from that required to form the
phonogram-blank. When the wax or other material has become set. the core 0' is
removed from the mould through the opening P': the phonogram-blank, with its inner
lining of cord or thread.being subsequently taken out. The sound-recording material
may, however, be applied by dipping the backing whilst on the core into the melted
The complete
material; the outer surface being afterwards. turned in a lathe.
cylinder or phonogram-blank is shewn in Fig. 63: O being the lining or backing of
thread or cord and H the wax or wax-like material.
When the outer recording material is one which is comparatively soft and pliable at
ordinary temperatures, such a soft wax, a backing of cord or even one of paper or
the like may be readily used; but it has been found better for the purpose of
recording and reproducing sounds to employ as the recording material one which is

page_text: hard and brittle at ordinary temperatures. When such a material is employed,
difficulty may arise under extreme changes of temperature, because, owing to lack
of pliability, the outer surface cannot accommodate itself to the expansions and con-
tractions of the backing or lining, and is consequently liable to become cracked or
broken. To obviate this, the two parts of the cylinder, that is, the inner part or
backing and the outer part or recording surface, are made of substances which
expand and contract under changes of temperature to the same or practically the
same extent. When, for the sound-recording surface, a thin coating of a metallic
soap, such as stearate of soda, is used, the backing may be of an asphaltic or
bituminous substance, such as one of the natural asphalts or the residues which are
produced artificially. The best results have been produced by the use of Syrian
asphalt,but this is more expensive than some other kinds,and, therefore it is preferred
to employ asphalt-pitch, which is ordinary Trinidad asphalt from which the more
volatile substances have been distilled, and which is a cheap substance. A small
amount of carnauba wax or some other material which contracts greatly in solidifying
is mixed therewith, and causes the same to easily leave the mould. To asphalts
which are too thick to pour readily, even at high temperatures. a little wax of low
melting point; such as Japan wax, may be added; or, instead of the wax. a liquid,
such as crude petroleum or turpentine, may be used. In making the phonogram-
blanks, the asphalt or the mixture thereof is moulded with other material into a
cylinder having a taper bore; the cylinder, after it has cooled, being dipped into
melted sound-recording material. The sound-recording material may also be
applied by mouiding. The asphalt body, instead of being moulded, may be formed
by pressure from powdered asphalie: or, the cylinders may be formed in a squirting
press in a similar way to that employed in the manufacture of lead pipe.
Another good material for forming the backing and having about the same co-
eflicient of expansion as the metallic soaps (such as stearate of soda) used as the
recording material is hard rubber or ebonite, cylinders of which may be made in the
usual manner of making articles of hard rubber. If it be desired to vary the rate of
expansion of the stearate in order to make it conform to the rates of expansion of
different qualities of rubber, a suitable quantity of an oleate of a metal may be mixed
with the stearate. For instance, if the sound-recording material employed be mono-
stearate of soda, its rate of expansion may be increased by adding a small quantity of
oleate of alumina. In Figs. 64 and 65. H is the backing of asphaltic or bituminous
substance, or of hard rubber: H' being the outer coating of sound-recording
material, such as stearate, of soda or a mixture thereof with some
ingredient.
other
The
The phonogram-cylinders so far described are of a stiff inflexible nature.
object of a part of this invention is to make phonogram-blanks which are flexible.
and which may be conveniently packed and enclosed in envelopes for transmission
by mail or otherwise. For this purpose. thin flexible sheets of wax or wax-like
material are employed,such sheets being used, either by themselves or combined with
backings of other material, as the recording surfaces. To make these sheets, the
material may be rolled or pressed into shape, but it is found best to make them by
forcing the material through an aperture of the right form. such as q. in a press
such as Q (Fig. 66). The material is raised to a temperature which will insure
its easy passage through the aperture. The strip or sheet is preferably received in a
vessel containing water, so as to cause it to set immediately. After it is dry, it may
be coated with fine powder, such as talc or kaolin, to prevent its surfaces adhering
to other objects. The sheets thus formed may be used in a variety of ways. They
may themselves form flat recording surfaces for the phonograph. or they may be
attached to sheets of paper or other flexible material and so used, or they may be
formed into cylinders either with or without an internal backing of paper or like
material. They may also, if desired. be placed upon rigid cylinders or backings.
Many different compounds of wax or wax-like materials may be employed for this
purpose. A mixture of asphalte with Japan wax or other material for increasing its
flexibility has been found most useful. The asphalte alone is brittle, even in ibju

page_text: The
sheets, but its flexibility may be increased to any desired degree by adding less or
more of the Japanwax or other substance for imparting flexibility. To makecylinders
or phonogram-blanks from sheets formed by the press Q or otherwise, the sheet
may be bent round a forming cylinder and the ends pressed together; or the ends
may meet and be joined by heat. Such a phonogram-blank is shewn in Fig. 71.
Or, a sheet of thin paper o may be formed into a cylinder with its edges joined, the
cylinder being then collapsed, as shewn in Fig. 69, into a flat double sheet.
double sheet is then placed between two sheets of the flexible wax-like material
and the whole submitted to pressure, the sheets being thus made to adhère firmly to
the paper, whereby a collapsed phonogram-blank is formed which may be distended
into a cylinder for use. A solvent of the flexible material, such as benzol, is used.
to make the parts adhere. The cylinder, when completed and as extended ready for
use, is represented in Fig. 70. Instead of a backing of paper, the thin flexible sheets
may be covered with a varnish, such as a solution of a suitable gum, like gum balata,
in a solvent such as bi-sulphide of carbon. A number of sheets of this character may
be formed into a composite cylinder, as shewn in Fig. 72, from which they may be
torn one by one as they are used. Cylinders may be formed directly by the action
of a press if the aperture g of the press be of annular shape, as illustrated in
Fig. 68 in which case, the material, when forced out, is in the form of a
cylinder.
It is difficult to place thin flexible sheets of the kind just described on the paper
cylinder with which the phonograph is provided. To enable such sheets to be
readily used on the phonograph, a false shell R is provided, which has a cylindrical
outer surface and a taper bore so that it may fit on the cylinder of the phonograph;
devices for holding the sheet in position being added. One way of accomplishing
this is to furnish the faise shell with numerous fine sharp points which enter the
flexible sheet without penetrating entirely therethrough; the sheet being thus firmly
held. The false shell is also made with a raised flanger, which serves as a straight
guiding edge when the sheet 2 is being bent round the shell. The false shell may be
made in two parts R1 and R2 hinged together at r', as shewn in Figs. 77, 79 and-80;
their meeting edges having projecting pins and perforations, the pins on one
edge entering the perforations in the other. In this case the phonogram-blank l
should have small perforations at its ends; the flexible intending material being
omitted at these parts. The flexible sheet is readily placed on the open hinged shell
(see Fig. 80), and is held by the pins entering the holes in the sheet. The
shell is then closed round the phonograph-cylinder, which it is made to fit, and
locked by a suitable catch R provided for the purpose; the phonogram-blank being
thereupon in position for operation.
Having now particularly described and ascertained the mature of this invention and
in what manner the same is to be performed, I claim :-
1. In a phonograph, the improved means, substantially as lierein described, whereby.
the position of the recording or the reproducing point relatively to that of the record-
surface is automatically adjusted or determined.
2. In a phonograph, the combination, with a spectacle-frame, the guide-rest, the
tilting bar and the spring-presser, of the auxiliary presser-foot having a locking
tooth for preventing the spectacle-frame from being lowered when the tilting bar is.
accidentally left in a tilted position, substantially as herein described.
3. In a phonograph, the combination, with the rocking holding arm and the.
traveller-arm loosely connected together, of the cam moved by the rocking holding
arm, and the prop-arm worked by the cam and serving to lift the traveller-arm
whenever the rocking holding arm is lifted, substantially as herein described.
4. The use, with a phonograph, of a cover enclosing the upper half of the
phonogram-cylinder, with the exception of an opening for the recording and the
reproducing devices; the outer end-plate of the cover being attached to the swinging
arm to which the phonograph-shaft is pivoted, substantially as herein described.
5. The use, in a phonograph, of a recording point having a cutting edge shaped as

page_text: an arc of a circle whose centre Is Outside the surface for receiving the recor,
substantially as herein described.
6. The use, in a phonograph, of a recording point having a circular cutting edge
which may be turned so as to bring different portions thereof into position for
operation, substantially as herein described.
7. The use, in a phonograph, of a recorder or reproducer whereof the point is
removably connected with the diaphragm by means of a shank or stem extending
from the point into a holding sleeve connected with the diaphragm, substantially as
herein described.
8. The use, in a phonograph, of a reproducing point having a spherical or partly
spherical bearing surface, substantially as herein described.
9. In a phonograph, the combination, with the electric driving motor, of a circuit-
breaking governor having a sleeve moved by centrifugal balls, a fixed contact-spring
in constant connection with a plain surface upon such sleeve, and an adjustable
contact-spring for making and breaking contact with a disc upon the sleeve, sub-
stantially as herein described.
10. The use, in a phonograph, of a cutting knife or turning-off tool placed obliquely
and curved to conform to the surface of the cylindrical phonogram, substantially as
herein described.
11. The use, in a phonograph, of a cutting knife or turning-off tool provided with
a cutting edge having a part extending laterally therefrom, such part being
adapted to rest on the shoulder formed in cutting, substantially as herein described
12. The use, in a phonograph, of a cutting knife or turning-off tool, whereof the
cutting edge is formed at the junction of two plane surfaces which meet at an angle
of ninety degrees or thereabouts, substantially as herein described.
13. The use, in a phonograph, of a cutting knife or turning-off tool whereof the
cutting part is formed of a jewel such such as sapphire, secured by a clamp to the
stock of the tool, substantially as herein described.
14. The use, in a phonograph, of a cutting knife or turning-off tool provided with
a projecting shoulder or shoe for breaking up the chips or shavings, substantially as
herein described.
15. The use, in a phonograph, of a conveying chute so arranged in relation to the
cutting knife or turning-off tool that the shavings or chips rise from the edge of the
knife into the chute, substantially as herein described.
'
16. Treating the surface of a phonogram-blank made of hard and brittle material
with a substance which softens or toughens it, substantially as herein described, and
whereby a soft or tough surface instead of a hard brittle one is presented to the
action of the turning-off.
17. In the manufacture of phonogram-blanks, the employment of a backing of
lining consisting of a close even winding of thread or cord. substantially as herein
described.
18. In the manufacture of phonogram-blanks, the employment, substantially as
herein described, of an outer coating, such as a metallic soap. for receiving the
sound-record, and an inner core or backing of a material having the same or
practically the same coefficient of expansion, such as an asphaltic or bituminous
substance or hard rubber.
19. In the manufacture of phonogram-blanks. the employment, substantially as
herein described, of thin flexible sheets of wax or wax-like material, such sheets
being either furnished with or used without a backing or lining.
20. The manufacture of composite phonogram-blanks formed of a number of
a number of sheets massed together, substantially as herein described.
21. In a phonograph, the use of a false shell adapted for mounting on the
phonogram-cylinder and provided with a number of sharp points and a guiding
flange for receiving and holding a flexible phonogram-sheet. substantially as herein
described.
22. In a phonograph, the use of a hinged false shell adapted for mounting on the

page_text: phonogram-cylinder and provided with registering pins and holes in its edges for
receiving a flexible phonogram-sheet, substantially as herein described.
23. For supporting the vertical shaft of a phonograph-motor, the employment of a
step consisting of an adjustable piece formed with a cup in which a rough jewel,
ground flat on its projecting face, is embedded in a body of cement, substantially as
herein described.
Dated this 10th day of February 1800
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C.. Agent for the Applicant.