IиPROVE- WENTS IN THE GRINDING AND POLISHING OF CURVED AND ROUNDED SURFACES
Year: 1856

page_text: LETTERS PATENT to William Moberly, of Ravenhead, near St. Helen's,
in the County of Lancaster, Gentleman, for the Invention of "IиPROVE-
WENTS IN THE GRINDING AND POLISHING OF CURVED AND ROUNDED SURFACES."
Sealed the 20th February 1857, and dated the 4th September 1856.
PROVISIONAL SPECIFICATION left by the said William Moberly at the
Office of the Commissioners of Patents, with his Petition, on the
4th September 1856.
I, WILLIAM MOBERLY, of Ravenhead, near St. Helen's, in the County of
Lancaster, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE GRINDING AND POLISHING OF CURVED AND ROUNDED
SURFACES," to be as follows:-
This Invention relates to a novel mode of grinding and polishing curved or
rounded surfaces, such as cylinders and concave and convex lenses. The
materials designed to be operated upon are stone, glass, metal, and other hard
substances.
In grinding or polishing cylinders according to my Invention, I mount the
material to be worked (whether it be a solid block or hollow) on suitable
centres, which will admit of its turning freely on its axis. These centres are
carried by a swivel frame, jointed to a fixed frame or crosshead. Below the
material or several blocks of the material thus mounted, I place a circular
table or disc, which is keyed to a vertical shaft, and receives through it a rapid
rotary motion. This table and the swivel frame or frames carrying the material
to be ground or polished are so mounted excentrically with regard to each

page_text: other, and the material is so adjusted that, as the table (which is the grinding
surface) rotates, it will give by friction of contact rotary motion to the material
carried by the swivel frame or frames. Sand or other grit or polishing powder
being applied to the table in suitable quantities, and rotary motion being given
to the table, the material mounted on the centres will rotate on its axis, and
so present its entire periphery to the action of the grinding or polishing sur-
face; at the same time, in consequence of the varying surface speeds of the
different parts of the table that come in contact with the material to be ground,
the swivel frame with its load will rotate on its centre, and thus the contact
surfaces of the table and block will continually change, thereby ensuring a
rapid and true grinding or polishing action. When concave surfaces are
required to be ground and polished on this principle of frictional rotation, the
table, instead of being flat as in the former example, must receive the counter-
part of the form required to be imparted to or possessed by the object to be
operated upon. The object, say a lens, is presented either singly or in numbers
to the polishing surface by a fixed holder or holders, so arranged as to admit
of the lens receiving an independent axial motion, and each lens is so placed
with respect to the polishing surface, that when brought into contact therewith,
it will receive an axial motion by reason of the difference in the speed of rota-
tion of the various parts of the surface of the convex polisher with which it is
at one and the same time in contact. The polishing or grinding operation will
therefore be effected, as before stated, with great accuracy and dispatch. In
order to operate upon convex surfaces, concentric rings (concave in section) are
formed in the face of the grinding or polishing table, and the lenses or other
articles, being mounted in holders as in the last example, and arranged so as
to present only a portion of the lens (at one time) to the action of the groove,
the proper grinding or polishing grit being applied, and rotary motion being
imparted to the table, the grinding or polishing of the several lenses presented
to the action of the concave rings of grinding surfaces will take place
simultaneously.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Moberly in the Great Seal Patent Office on the
4th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MOBERLY, of Ravenhead, near Saint Helen's, in the County of Lancaster, 3
Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Moberly, Her special license that I, the said William Moberly, my
executors, administrators, and assigns, or such others as I, the said William
Moberly, 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 "IMPROVEMENTS IN THE GRINDING AND
POLISHING OF CURVED AND ROUNDED SURFACES," being partly a communication
from abroad, upon the condition (amongst others) that I, the said William
Moberly, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Moberly, 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, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say):-
This Invention relates to a novel mode of grinding and polishing curved or
rounded surfaces, such as cylinders and concave and convex lenses. The
materials designed to be operated upon are stone, glass, metal, and other
substances capable of being ground, or of receiving a polish.
In grinding or polishing cylinders according to this Invention, I mount the
material to be worked (whether it be a solid block or hollow) on suitable
centres, which will admit of its turning freely on its axis. These centres are
carried by a swivel frame, connected to and supported by a fixed frame or
crosshead. Below the material or several blocks of the material thus mounted,
I place a circular table or disc, which is keyed to a vertical shaft, and receives
through it a rapid rotary motion. This table, and the swivel frame or frames
carrying the material to be ground or polished, are mounted excentrically with
regard to each other, and the material is so adjusted in its frame that as the
table (which is the grinding surface) rotates, it will give by friction of contact
rotary motion to the material carried by the swivel frame or frames. Sand or
other grit or polishing powder being applied to the table in suitable quantities,

page_text: and rotary motion being given to the table, the material mounted on the
centres will rotate on its axis, and so present its entire periphery to the action
of the grinding or polishing surface; at the same time, in consequence of the
varying surface speeds of the different parts of the table that come in contact
with the material to be ground, the swivel frame with its load will rotate on
centre, and thus the contact surfaces of the table and block will continually
change, thereby ensuring a rapid and true grinding or polishing action.
When convex or concave surfaces are required to be ground and polished
on this principle of frictional rotation, the table, instead of being flat as in the
former example, must receive the counterpart of the form required to be
imparted to or possessed by the object to be operated upon. The object, say
a lens, is presented either singly or in numbers to the polishing surface by a
holder or holders, so arranged as to admit of the lens receiving an independent
axial motion, and each lens is so placed with respect to the polishing surface,
that when brought into contact therewith, it will receive an axial motion by
reason of the friction of contact between it and the table or polisher.
In order that the Invention may be clearly understood, I have shewn in
the accompanying Drawings views of various machines or apparatus suitable
for grinding different forms of curved surfaces (viz.) concave, convex, or
cylindrical.
Fig. 1 represents an elevation of an apparatus for grinding and polishing
cylinders, and Fig. 2 is a plan view of the same.
A is the polishing disc or table mounted on a vertical central shaft A', pro-
vided with suitable driving gear for transmitting rotary motion to the shaft and
table from any motive power engine; B is a forked holder, in the pendent
arms of which the cylinder roller to be polished is secured, or mounted in such
a way as to admit of its freely turning on its axis. This holder is attached to
a vertical spindle C, which passes up through the socket of a moveable brace E,
which works in a slot in the horizontal frame D above. The brace E may be
fixed to any required part of the frame D by means of a set screw nut a, and
in its socket the spindle C will be allowed to revolve freely. Additional
pressure may be imparted, if necessary, to the roller or cylinder to be operated
upon, either by means of a spring, or by placing weights upon the holder B.
The grinding surface is supplied from time to time with sand or other grit,
and either with or without water, as may be deemed desirable.
The radial difference of the friction of the table or disc A on the two
ends of the cylinder or roller causes the latter to move round on the central
spindle C, at the same time that a second revolving movement of the cylinder
on its own axis is produced. This compound movement of the cylinder or

page_text: roller causes a constant transposition of the surfaces in contact, and thus the
cylinder is quickly brought to a perfect form, and a surface obtained free from
scratches. The process may be continued until the desired surface is obtained.
If high polish is required the disc or table A may be covered with felt, leather,
or any other suitable substance, with or without emery or any other usual
polishing material, and with or without water, as may be found most desirable
under the circumstances.
be fastened.
Fig. 3 is a sectional elevation, and Fig. 4 a plan view, of an apparatus
for grinding and polishing convex surfaces. A is an upright central shaft or
spindle, on the upper end of which a disc or table of any required form may
In the present instance the working surface of the rotating disc
or table B is concave. It is made of iron, or any suitable material which will
admit of its being fastened on the top of the spindle A when a surface is to
be ground convex.
For grinding concave surfaces the convex disc C, shewn detached at Fig. 5,
is used. D is a runner of wood or other suitable material, having a spindle b
fixed to its upper surface; E is a frame intended to carry the runner D, and
which may either be slotted or solid. This frame may be larger or smaller
according to the work in hand, and there may be two or more of them crossing
each other, or in any requisite position. F is a moveable socket, which is
capable of being moved along the frame E, but may be fixed at any desired
part of the frame by a screw nut. The socket F has a bearing in which the
spindle 6 of the runner D can freely revolve, and as the socket is capable of
being itself turned on an axis and secured in any desired position, it may be
made to give any required inclination to the spindle 6. G is a block or piece
of glass or any other material to which a perfectly true or polished curved
surface (in this instance a convex surface) is desired to be given. The block
should by preference either be cast or reduced to something like the required
shape, whether concave or convex, before being introduced into the machine.
When this is done I fix the block G with pitch, rosin, plaster of Paris, or
other suitable holding material to the undeside of the runner D, and insert
the spindle b in the ring of the socket F, in such a position that the runner D
with its load will rest excentrically on the disc, which may be either the concave
disc B of Fig. 3, or the convexed disc C of Fig. 5. The shaft A is now caused
to revolve, and sand or other grit or polishing material is supplied, with or
without water or other liquid. The difference of friction upon that part of the
surface of the material (under process of grinding) nearest to the centre of
the disc, and on that nearest to its circumference will cause the runner D to
revolve rapidly on its axis, and the consequent revolution of the two surfaces

page_text: crossing each other perpetually will cause the glass or other substance to be
ground down to a true surface, exactly corresponding in curve to that of the
discs B or C. When a double concave or convex lens is to be ground, the
under side of the runner D is to be made convex or concave, as the case may
be, as the corresponding form will facilitate the attachment of the work to the
runner.
In order to change the curve of the lenses to be ground, the moveable
socket F is shifted on the frame E, and the direction of the spindle b is also
adjusted by the aid of a graduated scale fixed to the frame E, so that the
pressure of the lens on the grinding disc may be directed to any part of the
lens which it is desired to reduce. It will be evident that to grind either
concave or convex surfaces the same machinery may be used, the only change
required being the substitution of a convex for a concave disc, and vice versa.
In some cases it may be desirable to transpose the parts; in other words, to
place the glass or other material to be polished beneath the rotating disc or
table, and to grind it by means of a concave or convex runner, fastened to a
spindle A, and revolving by friction of contact as above.
Although the process as above described has reference mainly to the
operating upon one lens, block, or article at a time, it will be understood that
it is equally applicable to any number for which room can be found on the
grinding discs and frames.
Having now set forth the nature of this Invention of "Improvements in
the Grinding and Polishing of Curved and Rounded Surfaces," and explained
the manner of carrying the same into effect, I wish it to be understood that
I do not confine myself to the use of the precise arrangement of parts con-
stituting the machinery above described; but what I claim and desire to secure
by the above in part recited Letters Patent is, the grinding and polishing of
curved and rounded surfaces, as above described.
In witness whereof, I, the said William Moberly, have hereunto set my
hand and seal, the Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and fifty-seven.
W MOBERLY. (L.B.)