MACHINERY FOR THE MANUFACTURE OF OPTICAL LENSES
Year: 1853

page_text: LETTERS PATENT to Salomon Sturm, of Carpenters Buildings, in
the City of London, and of Vienna, in the Empire of Austria,
Optician, for the Invention of "MACHINERY FOR THE MANUFACTURE
OF OPTICAL LENSES."
Sealed the 11th April 1854, and dated the 11th November 1853.
PROVISIONAL SPECIFICATION left by the said Salomon Sturm
at the Office of the Commissioners of Patents, with his Petition,
on the 11th November 1853.
I; SALOMON STURM, of Carpenters Buildings, in the City of Lon-
don, Optician, do hereby declare the nature of the said Invention
for "MACHINERY FOR THE MANUFACTURE OF OPTICAL LENSES." to be as
follows:-
A cylinder or roller of cast iron or other suitable material is mounted
upon a horizontal spindle supported in bearings upon a frame so that it
may be caused to revolve by being connected to a steam engine or
other source of power. The lower part of the roller enters a hollow
semi-cylinder or segment of a cylinder of cast iron. or other suitable
material, which I call the cup, and which is capable of sliding upon a
bed which carries it. The cup receives a reciprocating end motion in

page_text: a direction parrallel with the axis of the roller by means of a crank or
otherwise, so that while the roller is revolving the cup is travelling
backwards and forwards endways. Means are provided for raising and
lowering the bed on which the cup slides, so as to bring it nearer to or
farther from the roller.
The roller has several facets formed upon it, or it may be made of a
hexagonal or polygonal form. On each of the facets of the roller a flat
plate is fixed by screws or otherwise, so that it may be readily removed
when required. These plates are taken off, and a rectangular hoop or
shallow box-without a-bottom is placed upon each plate, and the hoop
is then filled with melted pitch or other suitable cement.
A lid or
plate of metal is provided to fit on the top of the hoop, which is marked
with a straight line along the centre of its under side. A number of
pieces of glass or other substance which are to be converted into lenses
are each marked by means of a suitable instrument or guage with two
lines at right angles to each other, and on opposite sides of the glass or
other substance. These pieces are slightly attached by glue or other-
wise to the under side of the lid, which is removed from the hoop and
inserted for that purpose. The glasses are placed so that the lines on
their lower surfaces accurately coincide with the centre line on the lid.
The lid is then inverted and placed upon the hoop, and pressed down so
as to imbed the glasses in the cement, and squeeze out the superfluous
cement. When the cement has set the lid is removed, leaving the
glasses imbedded and fixed in the cement. The plate is then fixed
upon the roller, and the other plates are also covered with glasses in a
similar manner and attached to the roller; the machine is then put in
motion, and the cup is raised until it comes into contact with the
glasses. It is supplied with embry and water or other suitable grinding
inaterials, and the glasses are thus ground to a cylindrical form on the
exposed side. They are then polished with the usual materials, and are
then removed from the machine, and each glass or lens turned over and
again cemented down as before. The glass is thus turned at right angles
to its former, position, owing to the lines marked on the glass being at
right angles to each other: The second side is ground and polished
as before. The piece of glass has now two cylindrical surfaces whose

page_text: curvatures are at right angles to each other, and as one surface corrects
the distortion produced by the other a magnifying lens is thus obtained.
To manufacture diminishing lenses the pieces of glass, &c. are placed
in the cup, and the roller is made cylindrical and without facets, and is
employed for grinding the glasses. In other respects the operation is
similar. Rollers and cups of different diameters are employed for
manufacturing lenses of different curvatures or focal lengths. For
lenses whose radii of curvature are large a segment only of the roller
may be used, and it may receive a reciprocating in lieu of a continuous
rotary motion. The machinery may also be so arranged that the roller
may receive both a continuous or reciprocating rotary motion and a
reciprocating end motion, in which case the cup may be stationary.
I also construct lenses in which the surface, in lieu of being per-
fectly cylindrical;, are of eliptical, parabolic, or hyperbolic, or other form
differing from a perfect cylinder, and I introduce the requisite altera-.
tions or modifications in the construction, arrangement, and position of
the lenses and machinery to enable the required curvature to be
produced. This is done by varying the position of the lenses on the
facets, and the required curvature is produced by so placing the glass,
&c. in the cement that the planes of the tangents to the centre of
each side of the lens, instead of being parallel, are inclined to each.
other at given angles.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Salomon Sturm in the Great Seal Patent Office
on the 10th May 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
SALOMON STURM, formerly of Carpenters Building, in the City of
London, and of Vienna, in the Kingdom. of Austria, now of Haver-
stock Street, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date, the Eleventh day of November, in the year.
of our Lord One thousand eight hundred and fifty-three, in the seven-

page_text: teenth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Salomon Sturm, Her special licence that I,
the said Salomon Sturm, my executors, administrators, and assigns, or
such others as I, the said Salomon Sturm, my executors, administrators;
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "MACHINERY FOR THE MANUFACTURE OF OPTICAL
LENSES," upon the condition (amongst others) that I, the said Salomon
Sturm, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Salomon Sturm, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Drawings, and to the figures and letters marked thereon, this is
to.say:
My Invention relates to the construction of machinery for the manu-
facture of optical lenses with cylindrical surfaces. It has been found by
opticians that a lens having two cylindrical surfaces the axes of which
are at right angles to each other has similar properties generally to an
ordinary double convex lens with two spherical surfaces, but, that it
possesses certain optical advantages over such ordinary lens. The
difficulty and expence of manufacturing such cylindrical lenses by
hand has hitherto restricted their use, but by means of my machinery
herein-after described I am enabled to manufacture cylindrical lenses
with great accuracy of form, and at less cost than they can be manu-
factured by hand.
Figure 1, Sheet I., of the accompanying Drawings is a front view
partly in section of a machine constructed according to my Invention.
Figure 2, Sheet II, is an end view of the same. The same letters.

page_text: refer to similar parts in each Figure. A is a cylinder or roller mounted
on a spindle B, which revolves in bearings a, a, supported by the
general framing of the machine C. The spindle B is driven by a
cord or band passing round the pulley D, which is connected by a
clutch E to the spindle. The clutch E carries a block X which is
pressed against another block Y in the framing, when the clutch is dis-
engaged. This acts as a break, and stops the roller. The pulley D is
shewn partly in section in Figure 1. F is an iron bed similar to the
bed of a lathe, which is supported at the two ends by the two screw
spindles G, G, which pass through nuts I attached to the bed F. On
the upper end of each of the two screw spindles G is a worm wheel J.
driven by an endless screw J on the horizontal spindle K, which carries.
at its extremity a wheel and handle L. By turning this handle the
bed F may be raised and lowered, but will always remain parallel to
the spindle B. M is a sliding carriage which is fitted to the bed F, as
shewn in the vertical section Figure 3, Sheet II. In this carriage M
are several dovetail grooves 1, 2, 3, 4, 5, 6, 7, which serve for fitting
and securing to it the hollow segmental piece or trough of cast iron N,
which I call the cup. The transverse section of the cup is shewn in
Figure 3; its interior surface is a segment of a cylinder of the same
radius as that required to be given to the lenses, and I find it advan-
tageous to make its length about double that of the roller A. m is a
strong pin attached to the sliding carriage M, and connected by the
connecting rod O with the pin n, which is capable of being fixed at
various distances from the centre of the revolving disc P. The spindle
of the disc P carries a bevel wheel o, which is driven by another bevel
wheel p on the spindle Q, which is supported by the brackets q, r,
attached to the bed F. R is a grooved pulley fixed on the spindle Q,
and driven by a cord or band S which passes round it and the upper
pulley D, and also round a moveable pulley T, which serves for
tightening the band or varying its tension when required.
pulley D is driven by a cord or band U connected with a steam engine
or other source of power. The roller A is thus caused to revolve while
the cup N slides to and fro under it. The pieces of glass which are
to be made into lenses are attached to the roller A, and the cup is
The

page_text: supplied with sand and water, emery, or other suitable grinding
materials. The roller and cup being set in motion, as herein-before
described, the handle L is gradually turned so as to raise the cup until
it comes in contact with the pieces of glass. The grinding operation
now commences, and the cup is gradually raised as the glass is ground
away until the glasses are ground to the cylindrical form. Finer
grinding materials are then employed, and afterwards polishing mate-
rials applied in another cup which is substituted in place of that first
employed for grinding.
The lenses being thus ground and polished on one side are removed
from the roller and inverted, and at the same time turned one quarter
round, and again attached to the roller; the plane sides of the glasses
are thus exposed, while the cylindrical sides are placed with their axes
at right angles to that of the roller. The grinding and polishing of the
second sides are then effected in the same manner as the grinding and
polishing of the first sides, and the lenses are thus completed. These.
lenses are convex on both sides, and are therefore magnifying lenses.
To manufacture diminishing lenses the glasses are fixed in the cup
instead of on the roller, which is then made cylindrical and of the same
radius as that required for the surfaces of the lenses. In this case the
roller may be advantageously made of about double the length of the
cup. A guard of sheet iron is placed on each side of the cup to pre-
vent the granting materials from being scattered about. Little cups or
gutters are also provided to receive the materials which overflow or are
thrown about, and convey them by a pipe into a basin placed for their
reception.
In order to attach the pieces of glass or other substance to the roller
or cup I employ detached plates shewn at 6 in Figure 3. These plates
bare attached by screws to the roller, and. on these plates the pieces
of glass are cemented, as herein-after described. Each piece of glass
is marked with a centre line on one surface, and with another centre
line at right angles to the first on the opposite surface. These lines
may be drawn by a writing or scratching diamond by placing a row of
the glasses between two frames or clamps, in one of which is a longitu-
dinal slit or groove, and in the other a number of transverse slits at

page_text: right angles to the longitudinal slit. By drawing the diamond along
the longitudinal slit the glasses are marked on one side, and by drawing
it along the transverse slits each glass is marked on the opposite
side. Any other convenient gauge may be employed for marking the
glasses.
"
The glasses after being marked are to be cemented to the plates b
in the following manner:-Figure 4, Sheet. II., is a side view shewing:
one of the plates 6; with the cementing apparatus; Figure 5, is a
longitudinal section; and Figure 6, is a transverse section of the same..
c, is a rectangular frame with a pin at each end, which enters a cor-
responding hole in the plate b. d, is a cover which fits the top of the
frame c. Figure 7 is a plan of the under side of the cover d; the
cover d is taken off and enveloped in a piece of paper, on which is
drawn a line which coincides with. the centre line of the cover; the
marked pieces of glass are then arranged along the paper, to which
they are attached by means of glue or any other suitable cement, taking
care to keep the centre lines on their lower surfaces on the centre line
of the paper. The frame' c is placed upon the plate b, and filled with
melted pitch or other suitable cement, and while the cement is still
fluid the cover. d with the glasses attached to it is inverted, and put
in its place on the frame c. When the cement has become solid the
cover d is removed, and the paper torn off or washed off from the
glasses. The frame c is also removed, and the glasses are thus left
embedded in the cake of cement on the plate b. In order to. cause.
the cement to adhere to the plate 6 this plate is warmed before the
operation, and the frame c is dipped in water and cooled, so as to pre-
vent the cement from adhering to it.
The plate b, with the glasses cemented to it, is now fixed by screws
in its place on the roller or in the cup, and the grinding and polishing
is conducted, as: herein-before described; when one side or surface. is
completed the lenses are detached from the cement, and again affixed
as before, the lines on their opposite surfaces now serving as guides for
arranging them on the cover d.
In lieu of cementing the glasses to a piece of paper they may be
cemented by pitch to the cover d, which is then made with several holes

page_text: or perforations. The cover is loosened and detached by dropping a
little oil of turpentine into the perforations for the purpose of softening
or dissolving the pitch.
In the machine shewn on the Drawings the roller has a rotary mo-
tion, and the cup has a reciprocating longitudinal motion, but the cup
may be made stationary, if preferred, and a reciprocating longitudinal
or end motion may be given to the roller. In lieu of an entire roller
a segment or segments of a roller may be employed, which may receive
a continuous or reciprocating rotary motion. This is more particularly
applicable for lenses of large radius, for which it might be inconsistent
to employ an entire cylinder of the necessary size. In lieu of em-
ploying an eccentric pin or crank for giving the reciprocating longitu-
dinal motion, such motion may be given by a screw, or by a rack and
pinion, or other suitable contrivance.
In some cases the two surfaces of the lens may be inclined towards
each other, so that it will then be somewhat thicker at one part of the
edge than at the opposite part. This is effected by cementing them on
the machine at the necessary angle. If such a lens be placed upon
a table with its lower surface horizontal, the upper surface will be
somewhat inclined, so that vertical sections of this cylindrical surface
will present ellipsoids instead of circles, and the lens will have similar
properties to those of a lens of ordinary construction which has been
ground to an ellipsoidal figure, instead of being ground to a true
sphere.
The effects of lenses of various other curves may be produced by
varying the angle and direction of the inclination of the surfaces.
In the above description I have mentioned glass as the material
employed for the lenses, but lenses of rock crystal or other suitable
substance may be manufactured in a similar manner. The cups which
I employ for grinding convex or magnifying lenses, and the rollers
which I employ for grinding concave or diminishing lenses, are of cast
iron. The corresponding cups and rollers employed for polishing the
leuses may also be made of cast iron, and covered with cloth or other
suitable material.
Having now described the nature of the said Invention, and in what

page_text: manner the same is to be performed, I wish it to be understood that I
do not claim as my Invention the manufacture generally of lenses with
cylindrical surfaces, such lenses having already been manufactured
by hand, nor do I confine myself to the precise details and materials
of the machinery herein-before described, provided that the peculiar
character of my Invention be retained; but what I claim is,-
Firstly, the construction of machinery for the manufacture of optical
lenses with a roller and cup arranged so as to combine a rotary with
a longitudinal motion, as herein-before described.
Secondly, the constructing the roller or cup with detached plates
furnished with frames and covers for facilitating the operation of
cementing to them the pieces of glass or other substance to be manu-
factured into lenses, as herein-before described.
In witness whereof, I, the said Salomon Sturm, have heretofore
set my hand and seal, this Tenth day of May, One thousand
eight hundred and fifty-four.
SALOMON STURM. (L.S.)
SALOMON STURM. (L.S.)