NEW OR IMPROVED MA- CHINERY FOR GRINDING AND POLISHING LENSES
Year: 1854

page_text: LETTERS PATENT to William Stevens, of Birmingham, in the County of
Warwick, Manufacturer, and William Stevens, junior, of Birmingham
aforesaid, Manufacturer, for the Invention of "NEW OR IMPROVED MA-
CHINERY FOR GRINDING AND POLISHING LENSES."
Sealed the 5th September. 1854, and dated the 21st March 1854.
PROVISIONAL SPECIFICATION left by the said William Stevens and
William Stevens, junior, at the Office of the Commissioners of Patents,
with his Petition, on the 21st March 1854.
We, WILLIAM STEVENS, of Birmingham, in, the County of Warwick,
Manufacturer, and WILLIAM STEVENS, junior, of. Birmingham aforesaid,
Manufacturer, do hereby declare the nature of the said Invention for "NEW OR
IMPROVED MACHINERY FOR GRINDING AND POLISHING LENSES" to be as follows:-
Our Invention consists of a vertical axis, on the top of which a concave
tool, having the curvature of the lens to be ground, is fixed; besides having a
rotatory motion the said axis has a vertical sliding motion. Over the concave
tool is another axis, on the bottom of which the lens to be ground is fixed in
any convenient manner; besides a rotatory motion the last-named axis has a
vibratory or pendulum-like motion in a vertical plane. On raising the concave
tool on the first-named axis against the lens, and communicating the rotatory
and vibrating motion to the second-named axis carrying the lens, the said
grinding tool being furnished with the usual grinding or polishing materials,

page_text: the grinding and polishing of the lens may be rapidly effected. A series of
axes (such as described) may be placed in one frame, and the motions described
may be communicated thereto by mechanical arrangements, to which we do
not think it necessary here to describe.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Stevens and William Stevens, junior, in the Great
Seal Patent Office on the 21st September 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
STEVENS, of Birmingham, in the County of Warwick, Manufacturer, and
WILLIAM STEVENS, junior, of Birmingham aforesaid, Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of March, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said William Stevens and William Stevens, junior, Her special licence that
we, the said William Stevens and William Stevens, junior, our executors,
administrators, and assigns, or such others as we, the said William Stevens
and William Stevens, junior, our 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 "NEW OR
IMPROVED MACHINERY FOR GRINDING AND POLISHING LENSES," upon the condition
(amongst others) that we, the said William Stevens and William Stevens,
junior, by an instrument in writing under our hands and seals, or under
the hand and seal of one of us, 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 William Stevens, do hereby declare
the nature of the 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, that is to say:-
Our Invention consists of a new or improved machine, represented in the
accompanying Drawing. Figure 1 of the said Drawing is a side elevation of

page_text: the said machine; and Figure 2 is a transverse vertical section of the same.
a is a vertical shaft or axis working in bearings; b, b, the lower end of the said
axis; a rests upon the short end c of the lever c, d, the said lever turning upon
the joint e. f. f', are a fixed and loose pulley on the axis a, by which said
pullies and the band passing thereover, the said axis a is thrown into and out
of gear with the driving machinery. The said axis a has a rotatory motion
communicated through the pulley f, and a vertical sliding motion communicated
by the lever c, d. g is a concave grinding tool having the curvature of the lens
to be ground; the said tool g is fixed on the top of the axis a. h is an axis
situated immediately over the axis a; the said axis h works in a bearing i; the
bearing i turns upon a centre k. A rotatory motion is communicated to the
axis h by a band passing over the pulley 7, and besides the said rotatory motion
the said axis h has a vibratory or pendulum-like motion upon the centre k;
the said centre is the centre of the curve to which the lens is to be ground.
The vibratory motion of the axis h is communicated thereto in the following
manner-m is a pulley driven by a band; the motion of the said pulley m
transmitted through the bevil gear n, crank o, and connecting rod p, com-
municates to the bars q, q, an alternate sliding motion. r is a cross piece which
engages in the bars q, q, by dropping in slots therein (two of these slots are
seen at s, s, Figure 1); the top of the axis h engages in a hole in the cross
piece r, and the reciprocating motion of the rods q, q, is transmitted through
the said cross piece ? to the axis h, to which it communicates the vibratory
motion described. t, t, are forked guides on the axis h, which said guides clip
the curved pieces u, u, and thereby give steadiness to the vibratory motion of
the axis h. The action of our machine is as follows:-The piece of glass to
be ground into a lens is attached to the lower end of the axis h in any con-
venient manner, as indicated at v. The tool g, on the top of the axis a, is
provided with the usual grinding or polishing materials, and the motions
herein-before described are communicated to the axes a and 7 through the
pullies f, l, and m; the end d, of the lever c, d, is depressed, and the axis
a thereby raised; the tool g having a rotatory motion is thus made to bear
against the piece of glass v, having a rotatory and vibratory motion. The
grinding or polishing of the lens is effected by the action of the grinding or
polishing materials in the tool g and the motions described. The end d of the
lever c, d, may be kept in a depressed state by a weight or spring, and the
tool g made to bear against the glass with any required pressure. The
framing w of the machine may be made to carry any number of pairs of axes
similar to the axes a, h; the positions of two pairs of such axes are indicated
by the lines x, y. As the said axes situated at x, y, resemble in every respect

page_text: the axes a, h, and have the same appendages, we do not think it necessary to
represent or describe the same.
Having now described the nature of our said Invention, and the manner of
carrying the same into effect, we wish it to be understood that we do not limit
ourselves to the precise method herein described and represented, as the same
may be varied without departing from the nature of our said Invention; for
example, the grinding tool may be attached to the upper axis, and the piece of
glass to be ground to the lower axis, the vibrating motion being given to the
lower axis instead of the upper; but we prefer the method described. We
claim as our Invention constructing machinery for grinding and polishing
lenses in the manner herein-before described and represented in the accom-
panying Drawing, that is to say, by fixing two axes one over the other, and
attaching the grinding tool and the glass to be ground to the opposed ends of
the said axes respectively, one of the said axes having in addition to its rotatory
motion a vertical sliding motion, and the other of the said axes having in
addition to its rotatory motion a vibratory or pendulum-like motion.
In witness whereof, I, the said William Stevens, have hereunto set my
hand and seal, this Twentieth day of September, in the year of our
Lord One thousand eight hundred and fifty-four.
Witness,
GEORGE SHAW.
WILLIAM STEVENS. (L.S.)