Improvements in and Apparatus for the Manufacture or Treatment of Wax or Wax-coated Tablets for Use in Graphophones or Apparatus for Recording and Reproducing Sounds.
Year: 1888

page_text: Date of Application, 13th Nov., 1888
Specification Accepted, 31st Dec., 1888
Improvements in and Apparatus for the Manufacture or Treatment
of Wax or Wax-coated Tablets for Use in Graphophones or
Apparatus for Recording and Reproducing Sounds.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex,
Gentleman do hereby declare the nature of this Invention which has been com-
municated to me from abroad by the Volta Graphophone Company of Alexandria
Virginia a corporation organised under the laws of the State of Virginia and having
an office in Washington District of Columbia and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
In
Ordinarily in tablets for graphophones or the like the wax surface in which the
record is made is supported by a tube or cylinder of paper or similar material.
the preparation of the wax tablet certain conditions must be secured in order to obtain
the best results in recording and reproducing. The wax must have a perfectly smooth
and true surface and it must be practically free from air bubbles. This latter condition
is of great importance and its attainment involves considerable difficulty. It is
found that notwithstanding the utmost care in the preparation of the wax the presence
of minute bubbles cannot in the ordinary manufacture be avoided.
The object of the present invention is to secure the favourable conditions above
indicated and generally to produce in a simple and expeditious manner graphophonic
tablets better suited for practical use than are those hitherto made.
In carrying out the present invention a paper tube or cylinder made in any
suitable way may be used as the foundation of the tablet and a coating of wax
may be applied to it in any suitable way as by immersion in a bath of melted
wax or otherwise. The tablet is then passed through a smoothing die heated in any
suitable manner (such for example as a surrounding water bath) to about the tempera-
ture of boiling water. In passing through this die the wax is melted and air bubbles
expelled and as the result of this step the surface is made comparatively smooth and
true. In this condition the tablet could be used for practical purposes but it is
desirable in order to attain the best results to submit it to a further operation as
follows:-
The surface of the wax after being passed through the smoothing die once or a
greater number of times remains slightly granular and presents a dull appearance to

page_text: '
remove which it is next passed through what is herein termed the polishing die
This is a steel die accurately fitting the cylinder externally and it is heated in
any suitable way to such temperature as to produce a highly polished smooth surface
upon the wax.
To attain this result the regulation of the temperature is of great importance. The
proper temperature may be found experimentally by observing the appearance of the
wax coating after passing through the die. If the wax exhibit a dull surface it
shews that the die is too hot. If on the other hand it presents longitudinal streaks
the die is too cold. As the limits within which the proper results are obtained are
narrow care must be exercised in this particular. Generally it may be said that the
temperature of the polishing die should be from about 170° to 190° Fahrenheit; but
as this may be found to vary with different kinds of wax as well as with the tempera-
ture of the wax itself the safest course is to determine the temperature by obser-
vation of the results with the particular kind of wax operated upon as above pointed
out.
This step in the process may of course be used in finishing tablets independently of
the use of the smoothing die or when some other mode of treatment has been used
preliminary to the polishing operation.
The accompanying drawings illustrate simple apparatus suitable for use in carrying
out the process though of course the invention is not limited to the apparatus shewn
which is given as an example of the best means with which I am acquainted of
carrying the invention into practical effect as applied to the treatment of cylindrical
tablets.
Fig. I is an elevation partly in section of the smoothing die. Fig. II is a plan
view thereof. Fig. III is a side elevation illustrating the polishing die and Fig. IV
is a partial front view and Fig. V a partial vertical section thereof.
A is a metal vessel adapted to contain water for the purpose of heating the
smoothing dio. B which at its ends is fastened to the top and bottom of the vessel A
and is entirely surrounded by the water of the bath. The die B should be three or
four inches long so that in passing through it the wax coated cylinder may be in
contact with the heated surface long enough to soften the wax throughout and to
expel air bubbles. The vessel A is shewn as supported above a gas stove M for the
purpose of heating the bath.
с
The polishing die c is a flat and comparatively thin plate preferably of steel having
a cylindrical opening corresponding in size to the diameter of the tablet a. It is
screwed to a horizontal plate or support D sustained by vertical rods E which also
constitute guide-ways for the carrier F. The carrier can slide vertically on the
rods E being raised by a cord ƒ and allowed to descend by gravity. The carrier F has
a guide tube g surrounding one of the rods E.
To the carrier Fis attached a core G exactly opposite to the die c. The end of the
core G is of a size to fit the tablet a internally and it is provided with a shoulder g¹
against which the end of the tablet a abuts the diameter of the core G above the
shoulder g' being such that it will pass freely through the die c.
The carrier F may be provided with weights H to give it proper momentum and
overcome resistance to the cylinder in passing through the die. Springs / surround
the rods E and rest on the plate or support D so as to act as buffers to check the
descent of the carrier and its attachments and prevent sudden jar.
A ring gas burner I is placed under the support or plate D for the purpose of
heating the die c to the proper temperature though obviously other means for heating
the die may be adopted. The heat is regulated by the key of the gas burner to keep 5
the die c at the proper temperature as hereinbefore set forth. •
The operation of finishing the tablet is performed as follows:-
The tablet a having received its coating of wax which may be applied roughly or
without great caro
passed through the smoothing die B, the latter being heated by
the hot water bath to about the temperature of boiling water and this may be repeated 5
several times if desired or until all air bubbles are removed and a comparatively
smooth and even surface obtained.

page_text: The tablet a is then placed on the end of the core G and the carrier F is raised by
means of the cord and guide K (Fig. V) which may be a wooden cylinder having
a conical point and is fitted in the lower end of the tablet to centre it accurately in
passing through the die c. Carrier F is then allowed to descend the tablet a passing
rapidly through the die c and receiving a highly polished surface. This operation
may likewise be repeated if desirable or necessary.
The tablets may if desired be made in tubes of considerablo length and after
smoothing and polishing be cut into cylinders of the standard size for use in
graphophones or the like.
It will of course be understood that the term wax as herein used includes generally
such waxy compositions or mixtures as are suitable for use as the recording medium
of graphophones or the like.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what I
claim is :-
1. In the manufacture of wax or wax coated tablets for use in graphophones or the
like passing the tablet through a smoothing die heated to a temperature above the
melting point of the said wax substantially as herein before described.
2. The process of preparing wax or wax coated tablets for use in graphophones or
the like by passing the tablets through a smoothing die heated to a temperature
sufficient to melt the wax and expel air bubbles and then passing the tablet through
a polishing die heated to substantially the temperature hereinbefore set forth.
3. The process of imparting a finish and polish to a tablet having a surface of wax
for use in graphophones or the like the said process consisting in passing the tablet
through a die heated to substantially the temperature heroinbefore set forth.
4. The apparatus herein described and illustrated in the accompanying drawings
for smoothing and polishing tablets for use in graphophones or the like.
Dated this 13th day of November 1888.