Phonograms and Apparatus therefor.
Year: 1888

page_text: .
Phonograms and Apparatus therefor.
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 the construction of phonogram blanks, which are the
blank surfaces for receiving the record in a phonograph, it also relates to phonograms
which are such surfaces after the record has been produced thereon, either by
indentation in a phonograph, or by Molding or Knurling from the record in relief.
The Invention also relates to processes for making such phonogram blanks and
phonograms. Such phonogram blanks and phonograms are preferably made with a
surface of wax or waxlike materials, so as to be readily indented with the record, and
are in the form of a hollow cylinder adapted to be mounted upon a suitable mandrel
carried by the phonograph.
In my patent No. 1644, dated 24th April, A.D., 1878, is described the use of paper
or other material coated with paraffine or other hydro-carbons, waxes, guns, or lacs.
I have found in practice that such waxes contract and expand under variations of
temperature to a much greater extent than paper, wood, inetals, and other similar
harder substances. While under ordinary conditions the wax or waxlike surfaces may
not be injured by this difference in the co-efficient of expansion, yet when subjected
to extreme cold, the contraction of the wax is so much greater than the harder
backing that the wax will crack and destroy the continuity of the surface. For
instance, a phonogram blank or phonogram may be subjected to a temperature of
nearly 100 degrees Fahrenheit at one time and at another time the temperature may
fall below zero.
If the waxy substance is sufficiently hard at the high temperature to
hold its shape under the pressure of one upon another in a packing box, it will at the
low temperature harden and contract so greatly in excess of the backing of harder
material that the wax will crack and render the surface useless.

page_text: By my present invention I overcome this difficulty by constructing the phonogram
blank or phonogram wholly of the wax or waxlike material, so that it will have the
same co-efficient of expansion, throughout its mass and contracting and expanding
alike will not crack under variations of temperature.
1 mold or otherwise form a cylindrical phonogram blank or phonogram of any
suitable wax or compound of waxes, but I have found that the articulation may be
greatly improved, and the loudness of the sounds increased while the scraping sounds
are reduced to a minimum by the production of a peculiar wax compound which
forms another feature of my invention. I have ascertained from a large number of
experiments that loudness and clearness of articulation and reduction of the scraping
sounds cannot be obtained by the use of the ordinary waxes of commerce alone, since
these are too soft. I overcome this difficulty by producing a proper mixture of these
soft waxes with hard or brittle waxes which of theinselves are not suitable for the
production of proper phonogram blanks and phonograms because alone they produce
excessive scraping sounds. But by properly proportioning the mixture, I have been
able to increase greatly the loudness and clearness of articulation whithout making the
scraping sounds excessive. As a hardening wax I have discovered that carnauba wax
is the best for mixing with the various soft waxes, and it may be used in various
proportions up to the point where, by reason of its hardness, it causes excessive
scraping sounds. The carnauba wax itself is very hard and brittle and utterly unit
for the production without mixture with other waxes of phonogram blanks. The
various qualities of ceresin, beeswax, spermaceti, paraffine, and other soft waxes of
commerce may have from 10 to 50 per cent. of carnauba wax mixed with them
without practically increasing the scraping sounds in the phonograph. The increasing
percentages of carnauba wax increase proportionately the volume of sound and the
clearness of articulation up to the point where the carnauba wax is in such excess as
to evince its presence by the scraping sounds. For the softer wax to mix with the
carnauba wax I prefer to use either ceresin, which is a wax obtained from ozokerite,
or beeswax, although other waxes may be employed. Ceresin or beeswax perfectly
disguise the scraping sounds produced by carnauba wax up to 50 per cent. or more
according to the temperature of the phonogram biank when manipulated, and hence I
prefer to use either of these two waxes. The percentage of carnauba wax to be added
depends also somewhat upon the shape of the recording point of the phonograph. If
the recording point is fine a larger proportion of carnauba wax can be added than if
a coarser point is used. Hence the proportions of the mixture may be varied largely,
any addition of the carnauba wax to the softer waxes producing proportionately good
results.
By reason of the excessive contraction of wax or wax compounds in cooling, I have
met with some difficulties in the making of phonogram blanks and phonograms from
these materials. The methods which I have produced for overcoming these difficulties
and for giving the surface of the phonogram blanks a high polish from other features
of my invention.
In molding the wax phonogram blank, I have found that if the wax be permitted
to become entirely cooled while still in the mold and surrounding the core, the
contraction of the wax is liable to cause it to crack. Hence after pouring the wax
into the mold, I permit it to set sufficiently to retain its form, and while it is yet hot
I remove the core so that the further contraction of the wax is permitted without the
danger of cracking.
Or I may provide a mold with a dividing strip running lengthwise thereof on one
side, so that when the melted wax is poured therein, the continuity of the cylinder
will be broken on one side, that is to say, the wax cylinder will be molded with a split
or opening on one side. On cooling the cylinder does not contract inwardly and thus
break, but in contracting draws away in both directions from the dividing strip
without the slightest danger of cracking. The wax may be left in the mold until
entirely cooled, and may then be removed. As it comes from the mold it has a break
of about a quarter of an inch, due principally to the contraction of the wax. The
broken cylinder is then put upon a suitable mandrel, and end pieces are fitted at the

page_text: ends of the break in the cylinder, when the break is poured full of hot wax which
perfectly fuses to the edges of the break and quickly cools and completes the cylinder.
Instead of taking the split wax cylinder from the mold, mounting it on the mandrel,
and pouring the split full of hot wax, the dividing strip of the mold may be made
removable, and may be taken out after the wax has set and the split can be closed
by pouring hot wax directly into the mold. Or the open sided cylinder can be
produced by molding or forming a flat sheet of the wax, and then while still sufficiently
plastic the wax sheet can be bent into a cylinder over a mandrel, and the edges fused
together with or without the addition of hot wax.
To finish the wax cylinders formed in any of the ways stated, it is necessary that
the bore of the cylinder as well as its external surface should be made perfectly true,
this I do by reaming out the cylindrical phonogram blank with a tapering reamer
since my blank has a tapering bore, and then by mounting the blank upon a suitable
tapering mandrel I may turn off its outer surface to a true cylinder. As a substitute
for the external and internal cutting of the blank, or in addition to it, I may press the
wax cylinder in a die of highly polished metal, preferably speculum metal, which is
the exact shape and size desired, both externally and internally and has surfaces which
are given a high polish so that upon the removal of the blank from this die it will be
ready for use and will have a highly polished surface which will enable it to receive
the phonographic record, and to reproduce the sounds with great perfection. The
blank is preferably put in this polishing and shaping die while still in a partially
plastic condition, say after its temperature has fallen to about 100 degrees Fahrenheit,
or if the blank has cooled its temperature may be raised to this extent.
Dated this 10th day of April 1888.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Phonogram Blanks and
Phonograms and Apparatus therefor.
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 manuer the same is to be performed to be particularly described
and ascertained in and by the following statement :—
This invention relates to the manufacture of phonogram blanks, which are bodies
having blank surfaces for receiving the record in a phonograph, as also to phono-
grams which are similar bodies after the record has been produced upon their surfaces,
either by indentation in a phonograph, or by moulding or impressing from the record
in relief. The invention further relates to processes for making such phonogram
blanks and phonograms. Such phonogram blanks and phonograms are preferably
made with a surface of wax or waxliko materials, so as to be readily indented with
the record, and are in the form of a hollow cylinder adapted to be mounted upon a
suitable mandril carried by the phonograph.
In the specification to Letters Patent granted to my foreign correspondent and
dated 24th April, 1878, No. 1,644, is described the use of paper or other material
coated with paraffine or other hydrocarbons, waxes, gums or lacs. It has been found
in practice that such waxes contract and expand under variations of temperature to a
much greater extent than paper, wood, metals and other similar harder substances.
While under ordinary conditions the wax or waxlike surfaces may not be injured by
this difference in the co-efficient by expansion, yet when subject to extreme cold, the
contraction of the wax is so much greater than the harder backing that the wax is
liable to crack, the continuity of the surface being thereby destroyed. For instance,
a phonogram blank or phonogram may be subjected to a temperature of nearly
100 degrees Fahrenheit at one time and at another time the temperature may fall
below zero.
If the waxy substance be sufficiently hard at the high temperature to
maintain its shape under the pressure resulting from the phonograms being packed
one upon another in a box, it will at the low temperature harden and contract so
greatly in excess of the backing of harder material that the wax will crack and its
surface be rendered useless.
By the present invention, this difficulty is overcome by constructing the phonogram
blank or phonogram wholly of the wax or waxlike material, so that it will have the
same co-efficient of expansion throughout its mass; and, contracting and expanding
uniformily under variations of temperature, will not cause the surface to crack.
The cylindrical phonogram blank or phonogram is moulded or otherwise formed of
any suitable wax or compound of waxes; but it has been found that the articulation
may be greatly improved and the loudness of the sounds increased, while the scraping
sounds are reduced to a minimum, by the production of a peculiar wax compound

page_text: which forms one of the features of this invention. As the result of a large number
of experiments, it has been found that loudness and clearness of articulation and
reduction of the scraping sounds cannot be obtained by the use of the ordinary waxes
of commerce alone, since these are too soft. This difficulty is overcome by producing
a proper mixture of these soft waxes with hard or brittle waxes which by themselves
are not suitable for the production of proper phonogram blanks and phonograms
because alone they produce excessive scraping sounds. But, by properly proportioning
the mixture, the loudness and clearness of articulation may be greatly increased
without making the scraping sounds excessive. As a hardening wax, my corre-
spondent has discovered that Carnauba wax is the best for mixing with the various
soft waxes; and it may be used in various proportions up to the point where, by
reason of its hardness, it causes excessive scraping sounds. Carnauba wax itself is
very hard and brittle and utterly unfit for the production without.mixture with other
waxes of phonogram blanks. The various qualities of ceresin, beeswax, spermaceti,
paraffine and other soft waxes of commerce may have from 10 to 50 per cent. of
Carnauba wax mixed with them without practically increasing the scraping sounds
in the phonograph.
The increasing percentages of Carnauba wax increase proportionately the volume
of sound and the clearness of articulation up to the point where the Carnauba
wax is in such excess as to evince its presence by the scraping sounds. For the
softer wax to mix with the Carnauba wax, it is preferred to use either ceresin, which
is a wax obtained from ozokerite, or beeswax, although other waxes may be employed.
Ceresin or beeswax perfectly disguise the scraping sounds produced by Carnauba
wax up to 50 per cent. or more according to the temperature of the phonogram
blank when manipulated, and hence either of these two waxes is by preference
employed. The percentage of Carnauba wax to be added depends also somewhat
upon the shape of the recording point of the phonograph. If the recording point
be fine, a larger proportion of Carnauba wax can be added than if a coarser point be
used. Hence the proportions of the mixture may be varied largely, any addition of
the Carnauba wax to the softer waxes producing proportionately good results.
By reason of the excessive contraction of wax or wax-compounds in cooling,
difficulties have been met with in the manufacture of phonogram blanks and phono-
grams from these materials. The methods which have been devised for overcoming
these difficulties and for giving the surface of the phonogram blank a high polish
constitute other features of this invention.
In moulding the wax phonogram blank, it has been found that if the wax be
permitted to become completely cooled while still in the mould and surrounding the
core, the contraction of the wax is liable to cause it to crack. Hence after pouring
the wax into the mould, it is permitted to set sufficiently to retain its form; and while
the wax is still hot, the core is removed so that further contraction of the wax is
permitted without involving danger of cracking.
Or the mould may be provided with a dividing strip running lengthwise thereof on
one side, so that when the melted wax is poured in, the continuity of the cylinder
will be broken on one side; that is to say, the wax cylinder will be moulded with a
split or opening on one side. On cooling, the cylinder does not contract inwardly
and thus break, but in contracting draws away in both directions from the dividing
strip without the slightest danger of cracking. The wax may be left in the mould
until quite cool, and may then he removed. As it comes from the mould it has a
break or gap of about a quarter of an inch, due principally to the contraction of the
wax. The broken cylinder is then put upon a suitable mandril, and stop pieces
baving been applied at the ends of the break or gap, the latter is poured full of hot
wax, which perfectly fuses with the edges of the break and quickly cools and com-
pletes the cylinder. Instead of taking the split wax cylinder from the mould, mounting
it on the mandril, and pouring the gap full of hot wax, the dividing strip of the
mould may be made removable, and may be withdrawn after the wax has set, and
the gap may then be closed by pouring hot wax directly into the mould. Or the
open-sided cylinder can be produced by moulding or forming a flat sheet of the

page_text: wax, and then, while still sufficiently plastic, the wax sheet can be bent into a
cylinder over a mandril, and the edges fused together without the addition of
hot wax.
To finish the wax cylinders formed in any of the ways stated, it is necessary that
the bore of the cylinder as well as its external surface should be made perfectly true.
This is accomplished by reaming out the cylindrical phonogram blank with a taper
reamer, since the blank has a taper bore; and then, by mounting the blank upon a
suitable taper mandril, its outer surface may be turned to a true cylinder. As a
substitute for the external and internal cutting of the blank, or in addition to it, the
wax cylinder may be pressed in a die of highly-polished metal, preferably speculum
metal, the die being of the exact shape and size desired, both externally and
internally, and having highly-polished surfaces, so that, upon the removal of the
blank, it will be ready for use and will have a highly-polished surface which will
enable it to receive the phonographic record and to reproduce the sounds with great
perfection. The blank is preferably put in this polishing and shaping die while still
in a partially plastic condition, say after its temperature has fallen to about
100 degrees Fahrenheit; or, if the blank has cooled, its temperature may be raised
to this degree.
Referring to the accompanying drawings, Figs. 1, 2 and 3 are respectively a side
elevation, a longitudinal section and an end view of the phonogram blank or
phonogram; Fig. 4 is a top view of the mould shewing the removable core; Fig. 5
is a vertical section through the mould, taken on the line 2-2 (Fig. 4), the mould
having been swung to the right; Fig. 6 is a top view of the mould shewing the
dividing strip; Fig. 7 is a view of the split cylinder produced from the mould
represented in Fig. 6; Figs. 8 and 9 illustrate the means employed for filling the
split in the cylinder with hot wax; Figs. 10 and 11 illustrate the formation of the
split cylinder from a flat sheet; Figs. 12 and 13 illustrate the micans employed for
making the cylinder true by reaming and boring; Fig. 14 is a vertical section
shewing the shaping and polishing die for finishing the phonogram blank.
With reference to Figs. 1, 2 and 3, A is the phonogram blank or phonogram made
entirely of wax as already described and having preferably a cylindrical surface and
a taper bore.
With reference to Figs. 4 and 5, B is a base upon which is pivoted a divided
cylindrical mould constructed in two parts CC binged together and having
handles c¹ for opening and closing the same. The base has an opening & over
which the mould can be swung when it is desired to remove the taper core D, the
latter being arranged with its small end uppermost. The wax is poured into the
mould through the funnel E, a hole F being provided for the escape of air. The
core having been placed in the divided mould, the latter is closed and swung to
the left to assume the position shown in Fig. 4. Molten wax is then poured in
through the funnel E until the annular space around the core is filled; a cylindrical
body having a taper bore being hereby formed. As soon as the wax is sufficiently
set to retain its shape, but before it has cooled to any great extent, the mould is
swung to the right thereby bringing the core D over the hole 6 in the base. The
core is then pushed down into the hole b, the effect being to practically remove it
from the mould, since by its taper form it is withdrawn from contact with the wax.
The wax having been permitted to cool further, the mould is opened and the wax
cylinder removed; whereupon the core may be lifted out of the hole band, together
with the mould, returned to its original position; the mould is then closed, and is
ready for another charge of molten wax.
With reference to Figs. 6, 7, 8, 9, 10 and 11, G is the external shell and H the
core of the mould, these parts being simple in character. The shell G and the core H
are connected on one side by a dividing strip J which runs the entire length of the
mould and prevents the wax meeting on one side. The wax is poured into the mould
and allowed to cool, when it will be found that the cylinder A' has contracted
sufficiently to permit of its easy removal. The cylinder A¹ when removed from this
mould have a break or gap a on one side. The cylinder is then mounted upon a

page_text: suitable mandrel K, and the filling box L is fitted over the gap a, this box having
stop-pieces which rest on the surface of the mandrel and close the ends of the gap,
while the side pieces rest upon the top of the wax cylinder at the sides of the
break. Hot wax is then poured into the box L so as to fill the gap in the cylinder.
The wax having cooled, the cylinder is removed from the mandrel and is ready for
finishing.
Instead of removing the split cylinder from the mould, the dividing strip J may be
removed and the split in the wax cylinder filled by pouring wax directly into the
mould. Or a cylinder with a break on one side may be produced by moulding or
forming a flat sheet A* of the wax, and then, while the wax is still sufficiently plastic,
bending this sheet over a mandrel K and closing the break by fusing the meeting
edges or filling the gap with hot wax.
With reference to Figs. 12 and 13, M is a taper reamer for reaming out the
interior of the moulded blank A, and N is a taper mandrel whereon the blank is
placed for turning its surface true by means of a cutting tube 0.
With reference to Fig. 14, P is a die having a cylindrical bore for receiving the
phonogram blank and providing with a shoulder p at its lower end. The wax
cylindrical phonogram blank is placed in this die, after which the taper plunger Qis
pushed into the bore of the blank. The plunger is forced forward by means of the
screw R and presses the blank against the walls of the surrounding die, thus giving
the blank the exact shape and size, both internally and externally, which may be
determined upon. The die and its plunger being of highly-polished metal, preferably
speculum metal, a high polish will be imparted to the surfaces of the phonogram
blank by this operation.
Having thus particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, what I claim as the invention
communicated to me by my foreign correspondent is :-
1st. A phonogram blank or phonogram constructed wholly of wax or waxlike
materials and, having the same co-efficient of expansion throughout its mass, sub-
stantially as herein described.
2ndly. A phonogram blank or phonogram constructed of a mixture of a hard
brittle wax with a softer wax, substantially as herein described.
3rdly. A phonogram blank or phonogram constructed of a mixture of Carnauba
wax and ceresin or beeswax, substantially as herein described.
4thly. In the manufacture of cylindrical phonogram blanks or phonograms of
wax, moulding or forming the cylindrical blank substantially as herein described to
prevent its cracking whilst cooling.
5thly. The process of and apparatus for moulding cylindrical phonogram blanks
and phonograms of wax, substantially as described with reference to Figs. 4 and 5 of
the accompanying drawings.
6thly. The processes of and apparatus for forming cylindrical phonogram blanks or
phonograms of wax, substantially as described with reference to Figs. 6, 7, 8, 9, 10
and 11 of the accompanying drawings.
7thly. The processes of and apparatus for finishing cylindrical phonogram blanks
or phonograms of wax, substantially as described with reference to Figs. 12, 13 and 14
of the accompanying drawings.
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