IMPROVEMENTS IN THE MANUFACTURE OF EMERY AND OTHER WHEELS USED FOR GRINDING OR POLISHING, AND IN APPARATUS EMPLOYED THERE- WITH
Year: 1875

page_text: LETTERS PATENT to John Cowdery Martin, of No. 5, Upper Hill
Street, Richmond, in the County of Surrey, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF EMERY AND OTHER WHEELS USED
Sealed the 6th October 1875, and dated the 30th June 1875.
PROVISIONAL SPECIFICATION left by the said John Cowdery Martin
at the Office of the Commissioners of Patents, with his Petition,
on the 30th June 1875.
I, JOHN COWDERY MARTIN, of No. 5, Upper Hill Street, Richmond,
in the County of Surrey, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF EMERY AND OTHER
WHEELS USED FOR GRINDING OR POLISHING, AND IN APPARATUS EMPLOYED THERE-
WITH," to be as follows:-
My Invention consists, firstly, in agglutinating together the particles
of emery or other similar material used in the formation of grinding
or polishing wheels by means of a composition consisting of glue, in

page_text: which is melted or dissolved a small quantity of the shreds or cuttings
of leather.
The second part of my Invention relates to a method of rendering
wheels compounded as above described perfectly safe, and quite free
from any liability to burst or fly to picces when driven at a high rate of
speed, and is applicable to all descriptions of wheels used for grinding
or polishing, whether made artificially, or of stone, or other natural
substance used for grinding or polishing. I apply this part of my
Invention to the various descriptions of wheels by making them thicker
towards the centre than they are at the periphery or grinding edge, that
is, supposing the grinding edge to be 3 inches thick the thickness at the
central hole might be 4 or 5 inches, which would give a large projection
on each side the wheel extending over the whole surface of the side.
Metal plates hollowed out to receive these projections are placed one on
each side the wheel, nearly covering it, and reaching to within an inch
or thereabout of the outer edge of the wheel. These plates are firmly
screwed against the wheel, and between them it is securely held.
Should now from any cause a rupture take place in the wheel it would
be impossible for the severed parts to fly asunder, as the thick part of
the wheel towards the centre could not pass through the narrower
opening between the plates towards the periphery of the wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Cowdery Martin in the Great Seal Patent
Office on the 29th December 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN 25
COWDERY MARTIN, of 5, Upper Hill Street, Richmond, in the County
of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of June, in the year of our Lord
One thousand eight hundred and seventy-five, in the thirty-ninth year of 30
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me the said John Cowdery Martin, Her special licence, that I, the
said John Cowdery Martin, my executors, administrators, and assigns, or
such others as I, the said John Cowdery Martin, my executors, admini-

page_text: strators, 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 MANU-
FACTURE OF EMERY AND OTHER WHEELS USED FOR GRINDING OR POLISHING, AND IN
APPARATUS EMPLOYED THEREWITH," upon the condition (amongst others) that
I, the said John Cowdery Martin, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands
and seals, 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 John Cowdery Martin, 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 :—
My Invention consists, firstly, in agglutinating together the particles
of emery or other similar material used in the formation of grinding or
polishing wheels by means of a composition consisting of glue, in which
is melted or dissolved a small quantity of the shreds or cuttings of
leather.
The second part of my Invention relates to a method of rendering
wheels compounded as above described perfectly safe, and quite free
from any liability to burst or fly to peices when driven at a high rate of
speed, and is applicable to all descriptions of wheels used for grinding
or polishing, whether made artificially, or of stone, or other natural
substance. I apply this part of my Invention to the various descriptions
of wheels by making them thicker towards the centre than they are at
the periphery or grinding edge, that is, supposing the grinding edge of
the wheel to be three inches thick the thickness at the central hole
might be four or five inches, which would give a large projection on
each side the wheel extending over the whole surface of the side.
Metal flanges or plates hollowed out to receive these projections are
placed one on each side the wheel, nearly covering them, and reaching
to within an inch or thereabout of the outer edge of the wheel. These

page_text: plates are firmly screwed against the wheel, and between them it is
securely held. Should now from any cause a rupture take place in the
wheel it would be impossible for the severed parts to fly asunder, as the
thicker part of the wheel towards the centre could not pass through the
narrower opening between the plates towards the periphery of the
wheel.
To make the composition I take one part by weight of leather reduced
to fine shreds, and boil or heat this from half an hour to an hour with
thirty-two parts of the best glue I can obtain, previously dissolved in
water, after which I strain out any undissolved portions of the leather, 1
and incorporate this mixture with three hundred and fifty parts of emery
powder of the required number or size of grain, the whole being then
pressed by means of a screw or other press into moulds of the size and
form required for the various wheels.
Referring to the Drawings, Fig. 1 shows a side view of the wheel:
with its covering plate; Fig. 2 shews a cross section of the wheel and
plates, with manner of securing them by means of a nut and screw;
Fig. 3 shews a different manner of forming the section of the wheel.
Upon the several Figures a shews the wheel, and 6 the covering plates.
I make the plates or coverings of metal or other sufficiently strong
material, using cast iron by preference, formed to fit closely over the
wheel, and permit of being firmly screwed against it by means of the
screw and nut, as shewn, or in any other convenient manner. As the
wheel becomes worn away by use I substitute smaller plates for those
first put on. The position of some of these is shewn by the dotted
lines c, d, on Fig. 1.
The form of the section may vary, but I prefer that the outline shall
be streight between the centre and circumference, as shewn by the
line e, f, on Fig. 2; but the section of the wheel may also be formed as
shewn at Fig. 3; or by the line e, f, on Fig. 2 being curved instead of
streight; or the section may be of any suitable outline which leaves the
wheel thicker at and towards the centre than at the grinding edge.
Although emery is described as the material of which the wheels are
made I do not confine myself exclusively to this, as any other suitable
material may be used; nor do I confine myself to the adhesive compo-
sition above described, or when using this to the exact proportions

page_text: herein set forth, as when making wheels of the form of section above
described I use any of the adhesive materials now employed in the
manufacture of emery wheels and artificial grindstones, and I also form
the wheels from any of the natural stones which now are or which may
be advantageously used for the manufacture of grinding wheels and
grindstones.
Having now described the nature of my said Invention, and the
manner in which the same is to be performed, I would have it under-
stood that what I claim and intend to be secured by these Letters Patent
is,―
Firstly. The adhesive composition formed by heating or melting with
each other glue and leather, for the purpose of agglutinating together
the particles of emery and other similar wheels.
And, Secondly. The form of wheel and covering plates, substantially
as described and illustrated, and for the purposes set forth.
In witness whereof, I, the said John Cowdery Martin, have here-
unto set my hand and seal, this Twenty-ninth day of December,
in-the year of our Lord One thousand eight hundred and seventy-
five.