AN IMPROVED METHOD OF AND MACHINERY FOR POLISHING THE SURFACE OF GLASS, STONE, METAL, OR OTHER MATERIALS CAPABLE OF BEING POLISHED BY FRICTON
Year: 1856

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the
Invention of "AN IMPROVED METHOD OF AND MACHINERY FOR POLISHING THE
SURFACE OF GLASS, STONE, METAL, OR OTHER MATERIALS CAPABLE OF BEING
POLISHED BY FRICTON."--A communication from Albert Broughton,
Alexander Lindsay, and John Ruthven Platt, all of New York, in the
United States of America.
Scaled the 5th September 1856, and dated the 30th April 1856.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
30th April 1856.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for AN IMPROVED METHOD OF AND MACHINERY FOR POLISHING
THE SURFACE OF GLASS, STONE, METAL, OR OTHER MATERIALS CAPABLE OF BEING
POLISHED BY FRICTION, to be as follows:-
This Invention consists in grinding and polishing flat surfaces by means of
a rotating plane of metal, stone, or other suitable material, the substances
whose surfaces are to be ground or polished being held in a suitable frame or
apparatus in such a manner, that the grinding or polishing friction exerted by

page_text: the said rotating plane upon the surfaces of the said substances will cause
them to rotate upon suitably arranged centres.
The most convenient form for the grinding and polishing surface is circular;
it therefore generally consists of the upper surface of a circular table or wheel,
which is secured firmly to a vertical shaft supported in suitable bearings. This
table or wheel, when employed for grinding and polishing plates of glass, may
be of cast iron, and made all in one piece, or in segments, which may be
secured together in any suitable manner. It is secured at the upper end of a
vertical shaft, which is supported in suitable bearings in a strong framing of
timber or iron. The upper end of the shaft is not allowed to stand above the
table, and therefore the article to be polished will be allowed to pass over its
centre. Rotary motion is communicated to this circular table. by means of
suitable gearing.
The apparatus for holding the plate of glass to be ground and polished
consists of a plate or frame of metal or wood, having a rim all round the
lower side, within which the glass is received in a bed of plaster of Paris, or
other suitable material; this plate or frame being secured to a wooden beam,
which is provided at the centre of its length with a perpendicular spindle
connected with a long lever, one end of which is fitted to turn on a fixed
pivot at the top of the framing, and the other end is capable of being moved
to bring the spindle nearer to or farther from the centre of the rotating
circular table.
The grinding and polishing operation is effected with the aid of sand, or any
polishing material that may be customarily employed, or that may be suitable.
To commence the operation, the plate of glass, having been secured in the plate
or frame, is placed on the rotating circular table, and the holding plate or
frame is connected with the long lever by means of its spindle. Rotary motion
is now given to the circular table, and when the. sand or grinding material is
properly distributed, the friction produced on that part of the plate of glass
which is at any time on that side of the spindle of the holding frame, which is
farthest from the centre of the table being greater than that on the part which
is at the same time on that side of the spindle nearest the centre of the table,
causes the plate to rotate in the same direction as the table. The sand or
grinding material, when a fresh supply is applied, will always distribute itself
evenly after a very few revolutions of the table.
The grinding may be regulated by a screw and nuts on the spindle of the
holding frame, so as to produce a pressure on the plate, additional to what is
produced by its own weiglit, and the weight of the plate or frame and other
parts of the liolding apparatus, or to take off some of tliat pressure.

page_text: For grinding and polishing slabs of marble, or other small articles, two or
more may be polished at the same time on the same rotating table, and hold-
ing apparatus of different kinds must be employed, according to the form of the
article. For instance, for holding the slab of marble up on edge, a different
construction of apparatus is required from that employed for holding it when
the surface is operated upon. The surface of the table for grinding and
polishing slabs of marble may be made of stone segments, secured to a
wooden disc or wheel, or in any other suitable manner. The structure or
character of the grinding or polishing surface may be varied to suit the
nature of the substance to be operated upon.
By producing the rotatory motion of the substances or articles to be ground
and polished on a rotating surface, by means of the friction of the said surface
upon the said substances or articles, an evenness and smoothness and freedom
from scratches are obtained, that cannot be obtained when the said rotary
motion is positive, as produced by gearing, as in some polishing machines
heretofore employed. Some of the reasons of this are as follow:-In the
former case, the grinding or polishing surface and surface to be ground or
polished undergo an infinite transposition, while in the latter they are
frequently in precisely the same relative positions. Again, when the motion is
produced by friction, it is found to be steady and free from the tremor which
is produced when an independent and positive motion is given.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office on
the 30th October 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of April, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Ierself, Her heirs and successors, give and grant unto me, the
said William Edward Newton, Her special license that I, the said William
Edward Newton, my executors, administrators, and assigns, or such others
as I, the said William Edward Newton, my exccutors, administrators, and
assigns, should at any time agree with, and no others, from time to time and

page_text: 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 "AN IMPROVED METHOD OF AND MACHINERY FOR POLISHING THE SURFACE OF
GLASS, STONE, METAL, OR OTHER MATERIALS CAPABLE OF BEING POLISHED BY
FRICTION," being a communication from Albert Broughton, Alexander Lindsay,
and John Ruthven Platt, all of New York, in the United States of America,
the condition (amongst others) that I, the said William Edward Newton,
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.
upon
NOW KNOW YE, that I, the said William Edward Newton, 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, as communicated to me by my foreign correspondents, relates
to an improved arrangement of machinery (applicable to the grinding and
polishing of flat surfaces), wherein the friction of a flat rotating polishing disc
or table is caused to give the material under operation an independent rotary
motion around its own axis, and thereby to ensure the equable distribution of
the grinding or polishing action over the whole surface of the material exposed
to or in contact with the rotating disc or table.
In the accompanying Drawings, Fig. 1 shews, in side elevation, and Fig. 2,
in plan view, the improved machine as adapted to the grinding and polishing
of large plates of glass; Fig. 3 represents the section of frame for holding
plates of glass while under the operation of the rotating table. These frames
will of course admit of considerable modification to suit the various substances
to be submitted to the action of the machine. A is the polishing disc or
circular table, mounted horizontally on a vertical shaft B, which runs in a foot-
step C, and is supported in a bearing carried by a cross framing C*. The
upper end of the shaft is not allowed to stand above the table, and therefore
the article to be polished may pass over its centre, when from its size it is
found desirable so to adjust the frame that carries it. The frame for holding
the plate of glass to be ground and polished consists of a plate or backing
piece D, of metal or wood, having a rima (see Fig. 3) all round the lower
side, within which the glass b (Fig. 3) is received in a bed of plaster of Paris

page_text: or other suitable material. This plate is secured by wedges in a recess made
in the lower side of the frame E, or by any other suitable contrivance. From
the middle of the frame E projects a perpendicular spindle or swivel pin d,
which passes through the slotted fixed framework F, and is clamped thereto
by a clamping nut e, working on a thread formed on the swivel pin. This
framework F is set above the polishing table, and it is slotted radially to
permit of the frames E, which carry the work, being adjusted to any required
position with respect to the centre of the polishing table. Or, instead of this
radially slotted frame, hand levers, having their fulcrum on the fixed frame
below, may be provided for carrying the frames E, and shifting their position
as desired on the rotating table, the levers being held in position by being
clamped to the ends of bars connected by fulcrum pins to the same fixed frame,
and situated relatively to the hand levers so as to form struts and keep them
in place.
The grinding and polishing operation is effected with the aid of sand, or any
polishing material ordinarily employed, or suitable for the purpose. In order
to commence the operation, the plate of glass or other material to be operated
upon is first secured in the frame E, and this frame is adjusted in the required
position, and its swivel or spindle clamped securely to the slotted frame-
work F, to prevent the shifting of the frame E. It will be understood, that
the greater the distance of the spindle from the centre of the table the more
intense will be the grinding or polishing action, by reason of the superior
surface speed of the table at its periphery. Rotary motion is given to the
table by means of bevil gearing, as shewn at Fig. 1, the bevil wheel 1 being
keyed to the driving shaft 2, and the bevil wheel 3 mounted loosely on the
shaft B. This wheel 3 carries a hollow friction cone, which receives a conical
block 4, that slides on a feather on the shaft B, and thus connects the shaft
with the loose wheel. 5 is a rock lever; and 6, a screwed rod for sliding the
block 4 on the shaft, and breaking and making contact with the hollow cone.
A yielding driving power is by this arrangement imparted to the shaft B, and
through it to the table A, so that when any obstruction occurs, the rotation of
the table will cease, and the breakage of the machinery be prevented. The sand
or other grinding or polishing substance having been properly distributed over
the table, water from a tap 7 is turned on, and allowed to trickle on to the
shute 8, which conducts it to the centre of the grinding or polishing surface.
The driving power being now applied, the plate of glass or other substance
contained in the frame or frames E (by reason of the friction produced on
that part of the surface exposed to the action of the friction surface farthest
from the centre of motion being greater than that on the part which is at the

page_text: same time nearest the centre of the table) will be caused to rotate in the same
direction as the table A. The sand or other grinding or polishing material, on
a fresh supply being applied, will always distribute itself evenly after a very
few revolutions of the table, and although when fed at a point near the centre
of the table a greater friction near the centre of the table than near the
edges may ensue, and thus temporarily cause the plate to rotate in the opposite
direction to the 'table, yet an even distribution soon takes place, which reverses
the rotation. The grinding may be regulated by the screw thread and nuts on
the spindle d of the holding frame, so as to produce a pressure on the plate
additional to what is produced by its own weight, and the weight of the frame
and other parts of the holding apparatus, or to take off some of that pressure.
I would remark, that for grinding and polishing slabs of marble, glass, or
other substance, requiring such operation, the surface of the table, instead
of being made in one single piece, may be constructed of segments, or other
conveniently shaped pieces of stone, glass, or other suitable material, secured
to a disc or wheel in any suitable manner. The structure or character of the
grinding or polishing-surface may be varied, to suit the nature of the substance
to be operated upon, and the treatment required. It may frequently be found
convenient to place two pieces of glass, marble, or stone in the same machine,
in such a manner that the surfaces thereof will be made to grind or polish
one another. For instance, one sheet of glass or marble may be secured in
the frame as above described, and the other on the rotating disc or table, and
upon the machine being put in motion the two surfaces will grind each other.
In order to prepare polishing plates of glass, it may be found convenient.to
employ two machines of the like construction, but having the rotating 'tables
somewhat differently faced; thus, in the first machine,.I place the rough.or
uneven 'glass to be submitted to a coarse grit, to reduce its inequalities and
prepare it for the after or finishing process. The table of the machines is
formed, by preference, of cast iron, and sand is employed as the cutting
substance. When the plate has been sufficiently reduced in this machine it
may be removed to another, the 'table of which it will be found convenient to
cover with 'felt, buff leather, or other soft substance, to which may be added
any suitable polishing powder. By producing the rotary motion of the
substance or articles to be ground and polished on a rotating surface, by means
of the friction of the said surface upon the said substances or articles, that
evenness, smoothness, and freedom from scratches is obtained, which is
unattainable in the same degree when the rotary motion is positive, or
produced by gearing, as in some polishing machines heretofore employed.
Some of the reasons of this are as follows:-In the former case, the grinding

page_text: or polishing surface and the surface to be ground or polished undergo an
infinite transposition, while in the latter they are frequently in precisely the
same relative positions. Again, when the motion is produced by friction, it is
found to be steady and free from the tremor which is produced when an
independent and positive motion is given.
Having now set forth the nature and object of the Invention communicated
to me by my foreign correspondents, and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part
recited Letters Patent I claim the general arrangement of parts herein shewn
and described, or any mere modification thereof, for grinding and polishing the
surfaces of glass, marble, stone, or other surfaces requiring such an operation.
I claim, particularly, communicating to the two surfaces which act on one
another-two distinct motions, one of such motions being an arbitrary, determi-
nate, and regular rotary motion, produced by means of gearing, or other
mechanical contrivances; and the other, a motion induced by the regular
rotary motion of the former, acting by the friction of contact of the one surface
on the other, and which second motion is therefore of a free and irregular
character.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Twenty-ninth day of October, in the year
of our Lord One thousand eight hundred and fifty-six.
Witness,
J. W. MOFFAtt.
66, Chancery Lane.
W. E. NEWTON. (L.S.)