IMPROVEMENTS IN MACHINES FOR TURNING WATCH CASES AND OTHER SIMILAR ARTICLES a com
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Instituto of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN MACHINES FOR TURNING WATCH CASES AND OTHER SIMILAR ARTICLES a com-
munication to me from abroad by La Société Dubail, Monnin, Frossard and
Company, of Paris, France, to be as follows:-
"
This Invention relates to machines for turning watch cases and other similar
hollow articles of any desired form, and it consists more especially in the means
employed for operating the gravers.
The machines for turning watch cases heretofore in use have generally been
provided with shaped gravors or cutters working in guides or cylinders and having
a uniform motion which is invariable. The turnings thus obtained differ con-
siderably from those obtained with hand gravers in which tho workman roughs-
out the article by using either the point of the cutter or one of its two faces, aftor
which he finishes the work by rounding off the angles and smoothing it. Theso
several results are obtained in a perfectly satisfactory manner by means of the
apparatus of this Invention with the aid of the pantograph.
The Invention is illustrated in the accompanying drawing, in which Figure 1
represents a side view of that part of the turning lathe or machine to which the
improvements are applied; Figure 2 is a front view of the same; Figure 3 shows
the graver in position on its holder, while Figures 4 and 5 show different positions
of the feeler or cutter guide with regard to the pattern which is an enlargement of
the same section as the article to be turned. -
Referring to the drawing, F represents a watch band mounted on the headstock
of the lathe, beneath which is a rest consisting of a sphere D formed in one with n
strong stem L. The rest is firmly mounted upon two regulating slides M N placed
one above the other, and by which the said rest may be adjusted and fixed in any
position desired. The headstock R is prolonged upwards and terminated by a
bracket which forms a small table T upon which the pattern P is placed. This
pattern which is the enlarged representation of the form of article to be turned,
is not placed directly upon the table but upon an intermediate plate which may
be shifted at will. The dimensions of the pattern is in this case five times larger
than that of the article to be turned. Supposing it is desired to reproduce the
band F, a section of which is represented at G, its dimensions would be increased
five times by means of a tracing point upon a steel plate of about 4 millimètres in
thickness, froin which is obtained the form or pattern P. This latter should be

page_text: fixed on the table in such manner that a line perpendicular to the bed of the lathe
will pass through the centre of the patterns P G and sphore D or thereabouts.
This is not however essential as the workman by a glance of the eye can always
ensure the requisite precision. The distances which should separate the spherical
head of the tool holder and the feelor are obtained as follows. I trace in the same
vertical plane three lines parallel to the bed of the lathe, the first through the
centre of the sphere, the second through the turning centre, and the third through
the middle of the pattern; in this particular case for example, there would be
between the 1st and 2nd lines-2 inches, between the 1st and 3rd lines-10 inches,
Graver or Cutter Holders. The graver here described suffices to reproduce all
external forms of cases, large or small, and rims as well as bands. The base of the
cutter holder O has a hemispherical cavity S, the centre of which is at D and of
the same dimensions as the sphere upon the rest which serves as a support therefor.
The graver is of triangular form, its cutting surface a b c being such that Dab
and Dac form two equal isosceles triangles whoso long sides measure two inches
in the present example. The feeler A B C consists of a triangular plate of steel
of from about one to two millimetres in thickness. It is fixed to the upper end
of the cutter holder O with the necessary accessories for its adjustment which
should comply with the following conditions:-
-
The five points Dab A B should be in the same plano, as should also be the
points D a c A C.. The point A should also be a prolongation of the straight
line D a, the point B a prolongation of D b, and the point C a prolongation of D c,
so as to form two equal isosceles triangles D A B and D A C whose long sides are
ten inches in length.
It should be noted that these two triangles are similar to D a b and Da o and
that their respective sides are in the proportion of five to ono.
The feelor A B C with its thin edges thus reprosonts the cutting edge of a graver
similar to the one operating but five times its sizo.
It will be seen that any right line drawn from the centre D to any point of the
inclined surface of the feeler will be always met by the cutter at which point_it
will be divided in the same ratio as the lines Da and D A or Db and D C or Dc
and D C, that is to say in the ratio of one to five, which is evident without further
demonstration.
The holders of the gravers for hollowing out the work are constructed on the
same principles but the "feelors" and gravers are of a dimension suited for tho
limited space in which they work. Figure 3 shows the graver mounted on its
holder.
The action of the machine will be sufficiently understood from the foregoing
description.
The pivoted graver or cutter holder can move in any direction, the gravers also
partaking in such movements while the "feeler" follows the outline of the pattern
and also moves in all directions. see figures 1 and 2. In this manner tho form
of the pattern is reproduced of one fifth the size; the operation being effected
alternately by pressure and by a sliding movement.
To avoid complication we have supposed the article to be turned in one operation,
but a secoud operation is necessarily required to shape that part held by the clamp,
for which purpose the pattern as well as the band is reversed. Although we have
adopted the ratio of 1 to 5 for this machine it is unnecessary to remark that such
proportion may be varied as found desirable,

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declaro the nature of the said Invention for "IMPROVEMENTS
IN MACHINES FOR TURNING WATCH CASES AND OTHER SIMILAR ARTICLES," (a com-
munication to me from abroad by La Société Dubail, Monnin, Frossard, and
Company, of Paris, France,) 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 machines for turning watch cases and other similar
hollow articles of any desired form and it consists moro especially in the means
employed for operating the gravers.
The machines for turning watch cases heretofore in use have generally been
provided with shaped gravers or cutters working in guides or cylinders and having
à uniform motion which is invariable. The turnings thus produced differ con-
siderably from those obtained with hand gravers in which the workman rought
out the article by using either the point of the cutter or one of its two faces, after
which he finishes the work by rounding off the angles and smoothing it. These
several results are obtained in a perfectly satisfactory manner by means of the
apparatus of this Invention with the aid of the pantograph.
The Invention is illustrated in the accompanying drawing, in which Figure 1
represents a side view of that part of the turning lathe or machine to which the
improvements are applied; Figure 2 is a front view of the same; Figure 3 shows
the graver in its holder, while Figures 4 and 5 show different positions of tho
feeler or guide finger of the cutter with regard to the pattern which is an enlarge-
ment of the same section as the article to be turned.
Referring to the drawing, F represents a watch band mounted on a mandril in
the headstock of the lathe, beneath which is a rest consisting of a sphere D formed
in one with a strong stem L. The rest is firmly mounted upon two regulating
slides M N placed one abovo the other, and by which the said rost may be adjusted
and fixed in any position desired. The headstock R is prolonged upwards and
terminated by a bracket' which forms a small table T upon which the pattern P is
placed. This pattern which is the enlarged representation of the form of article
to be turned, is not placed directly upon the table but upon an intermediato plato
which may be shifted at will. The dimensions of the pattern is in this case fivo
times larger than that of the article to be turned. Supposing it is desired to
reproduce the band F, a section of which is represented at G, its dimensions would
be increased five times by means of a tracing point, upon a steel plate of about
4 millimetres in thickness, from which is obtained the form or pattern P. This latter
should be fixed on the table in such manner that a line perpendicular to the bed
of the lathe will pass through the centre of the patterns P G and sphere D or

page_text: thereabouts. This is not however essential as the workman by a glance of the oye
can always ensure the requisite precision. The distances which should separate
the spherical head of the tool holder and the feeler are obtained as follows. I trace
in the same vertical plane three lines parallel to the bed of the lathe, the first
through the centre of the sphere, the second through the turning centre, and the
third through the middle of the pattern; in this particular case for example, there
would be between the 1st and 2nd lines-2 inches, between the 1 and 3rd lines--
10 inches.
Graver or Cutter Holders. The graver or cutter holder hero described suffices
to reproduce all external forms of cases, large or small, and rims as well as bands.
The base of the cutter holder O has a hemispherical cavity S, the centre of which
is at D and of the same dimensions as the sphere upon the rest which serves as a
support therefor. The graver is of triangular form, its cutting surface a b c being
such that Dab and Dac form two equal isosceles triangles whose long sides
measure two inches in the present example. The feeler ABC consists of a
triangular plate of steel of from about one to two millimetres in thickness. It is
fixed to the upper end of the cutter holder O and is provided with the necessary
means of adjustment which should comply with the following conditions:-
The five points Dab A B should be in. the same plane, as should also be the
points Dac A C. The point A should also be a prolongation of the straight
line Da, the point B a prolongation of D b, and the point Ca prolongation of Dc,
so as to form two equal isosceles triangles D A B and DAC whose long sides are
ten inches in length.
It should be noted that these two triangles are similar to Dab and Dac and
that their respective sides are in the proportion of five to one.
The feeler A B C with its thin edges thus represents the cutting edge of a graver
similar to the one operating but five times its size.
It will be seen that any right line drawn from the centre D to any point of the
inclined surface of the feeler will be always met by the cutter at which point it
will be divided in the same ratio ns the lines Da and D A or Db and D C or Dc
and DC, that is to say in the ratio of one to five, which is evident without further
demonstration.
The holders of the gravers for hollowing out the work are constructed on the
same principles but the "feelers" and gravers are of a dimension suited for the
limited space in which they work. Figure 3. shows one of these gravers mounted
on its holder.
The action of the machine will be sufficiently understood from the foregoing
description.
The pivoted gravor or cutter holder can move in any direction, the graver also
partaking in such movements while the "feeler" follows the outline of the pattern
and also noves in all directions. sec figures 1 and 2. In this manuer the form
of the pattern is reproduced of one fifth the size; the operation being effectod
alternately by pressure and by a sliding movement.
To avoid complication I have supposed the article to be turned in one operation,
but a second operation is necessarily required to shape that part held by the
mandril for which purpose the pattern as well as the band is reversed. Although
I havo adopted the ratio of 1 to 5 for this machine it is unnecessary to remark that
such proportion may be varied as found desirable.
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
A machine for turning watch casos and other similar articles of any form by
means of plain gravers guided by a pantograph, consisting in the combination of a
graver or cutter holder O mounted on a ball and socket joint D, the stem L of
which is adjustable in all directions by the slide rests M, N, a feoler A, B, C,

page_text: mounted upon the graver-holder, of the same form as the graver a bc, but being
an enlargement thereof and always remaining parallel therewith, a pattern P or
enlarged half section of the article to be turned, the enlargement of the pattern
with regard to the half section of the article, being in the ratio of the relative
dimensions of the feeler and of the graver, substantially as shown and described.