Improvements in Apparatus for Sawing or Cutting Stone, Metal, or other Hard Substances.
Year: 1893

page_text: Date of Application, 11th Mar., 1893
Complete Specification Left. 11th Dec., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Sawing or Cutting Stone, Metal, or
other Hard Substances.
I, ARTHUR JAMES HENDERSON, of 40, Lansdowne Road, Notting Hill, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows :-
My invention relates more especially to circular or other saws used for the
purpose of sawing or cutting stone of different kinds into blocks or slabs, and it has
for its object a novel method of making such saws so that they are very cheap,
durable, and effective.
Supposing that my invention is to be applied to a circular saw, I take a disc of
steel or other suitable metal, provided with a central hole by means of which it
can be fitted and fixed upon a spindle made to revolve by any suitable power in the
usual way.
I make the disc of sufficient thickness, but somewhat thinner than the width of
the cut which is to be made, but I make its outer circumference for a distance from
the periphery thinner than the remainder, a sufficient thickness of the metal being
removed upon each side of the disc (by turning or other convenient means) so as to
leave an angular ring round the body of the disc, of less thickness than the latter
and projecting from the centre of its edge.
Round the thinner projecting metal tongue described I form a coating of a hard
abrasive material, covering both sides of the tongue and also projecting for some
distance beyond its outer edge. This coating which I make somewhat thicker than the
body of the metal disc, forms the cutting surface, and is laid upon the metal tongue
when in a state sufficiently liquid by pouring or forcing it into a suitable mould in
which the disc has been laid, and in order to ensure its more perfect attachment to
the metal tongue I preferably make holes, the number and size of which may be
varied more or less, transversely through the metal tongue, the liquid abrasive mass
when it fills the mould also entering and filling the holes.
The abrasive material which I use to form the cutting part of the disc as
described, consists of grains or fragments of emery, diamond, or other sufficiently
hard substance, mixed with a cement of a kind similar to that for which Letters
Patent have been applied for by Olaf Terp, for "Improvements in the Manufacture
of Emery Wheels Grindstones Hones Millstones and the like "dated February 27th
1893, No. 4284.
This cement is prepared as follows:-
A
A saturated solution of chloride of calcium crystals is made, consisting of about
A saturated
equal parts by weight of the chloride of calcium and of water.
solution of chloride of magnesium crystals is also made, consisting of about
sixty six per cent. by weight of the chloride and thirty four per cent. of water.
mixture is then made of these two solutions, the average proportions being about
twenty per cent. by weight of the chloride of calcium solution to eighty per cent. of
the chloride of magnesium solution.
The mixture thus obtained is mixed with what is known as "bitter earth" (a
form of oxide of magnesia produced in Frankenstein, in Silesia, and known as
Bittererde," but which may also be obtained elsewhere or may be manufactured
artificially) in the proportion of about fifty five per cent. of the mixture and
forty-five per cent. of the "bitter earth," in order to form a cement or material
for binding together the grains of emery, diamond, or other hard cutting or

page_text: abrasive substance. The proportion of the latter may vary according to its
character and to the particular purposes to which the saw is to be applied.
The cement and the abrasive material having been thoroughly and carefully
mixed, the mixture is filled into the mould which has been prepared as already
described round the projecting tongue upon the disc which is to form the saw, to
which tongue the mixture very firmly and strongly adheres, the firmness of its
adherence being promoted by the holes in the tongue, which it also fills.
When dry, which may be in about 6 to 12 hours, the saw is removed from the
mould, and may be soaked in a mixture of petroleum and linseed oil, or other
suitable oil soluble in petroleum, in the proportion of about half of each, for the
purpose of rendering the cement non-hygroscopic, and the smoother face of the
abrasive cement may then be removed, if desired, by an emery wheel or other
equivalent means.
It is to be understood that the materials and the method of forming the abrasive
mass described, are similar to those described in the Specification of O. Terp
already hereinbefore referred to, and that my invention consists in the novel method
of applying such abrasive material to saws used for sawing stone or other hard
material, and of preparing the metal disc which forms the body of the saw to
receive the material.
The details, shape, and proportions of the parts of the saw, and of the materials
used to form the abrasive cement may be varied more or less to suit different
circumstances and conditions.
For instance, where a cut of considerable width is to be made the abrasive
cement may be applied to a fixed edge of the saw, without the latter having been
first reduced in thickness.
'Or, instead of a circular saw, a more or less straight one may be used, the
abrasive composition being applied in the way described to the cutting edge, which
is reduced in thickness and provided with transverse holes to receive it.
It is evident that my improved saw may be applied to cutting metals, or other
substances, as well as stone of different kinds.
The improved saw is very durable, effective, economical, and easily made and
repaired when necessary.
Dated this 11th day of March 1893.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Sawing or Cutting Stone, Metal, or
other Hard Substances.
1, ARTHUR JAMES HENDERSON, of 40, Lansdowne Road, Notting Hill, in
the County of Middlesex, Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement and accompanying drawing, that
is to say:
My invention relates more especially to circular or other saws used for the
purpose of sawing or cutting stone of different kinds into blocks or slabs, and it 4
has for its object a novel method of making such saws so that they are very cheap,
durable, and effective.
The accompanying drawing is in illustration of my invention, Figure 1 being a
sido view of a circular saw.
Figure 2 is a transverse section through the metal disc, and Figure 3 a transverse
section through the finished saw.
Supposing that my invention is to be applied to a circular saw, as illustrated, I

page_text: take a disc a of steel or other suitable metal, provided with a central hole 6 by
means of which it can be fitted and fixed upon a spindle made to revolve by any
suitable power in the usual way.
I make the disc a of sufficient thickness, but somewhat thinner than the width
of the cut which is to be made, and I make its outer circumference for a distance
from the periphery thinner than the remainder, a sufficient thickness of the metal
being removed upon each side of the disc (by turning or other convenient means)
so as to leave an annular ring at c round the body of the disc, of less thickness
than the latter and projecting from the centre of its edge, and either of uniform
thickness or somewhat thicker at its outer edge.
Round the thinner projecting metal tongue described I form a coating d of a
hard abrasive material, covering both sides of the tongue c and also projecting for
some distance beyond its outer edge or circumference.
This coating which I make somewhat thicker than the body of the metal disc a
forms the cutting surface and is laid upon the metal tongue c when in a state
sufficiently liquid by pouring or forcing it into a suitable mould in which the disc
has been laid, and in order to ensure its more perfect attachment to the metal
tongue I preferably make holes e, the number and size of which may be varied
more or less, transversely through the metal tongue, the liquid abrasive mass when
it fills the mould also entering and filling the holes.
The abrasive material which I use to form the cutting part of the disc as
described, consists of grains or fragments of emery, diamond, or other sufficiently
hard substance, mixed with a suitable cement or cementitious compound such as
that for which Letters Patent have been obtained for "Improvements in the
Manufacture of Emery Wheels, Grindstones, Hones, Millstones and the like,"
dated February 27th, 1893, No. 4284.
This cement is prepared as follows:-
A saturated solution of chloride of calcium crystals is made, consisting of about
equal parts by weight of the chloride of calcium and of water. A saturated
solution of chloride of magnesium crystals is also made, consisting of about sixty
six per cent. by weight of the chloride and thirty four per cent. of water. A
mixture is then made of these two solutions, the average proportions being about
twenty per cent. by weight of the chloride of calcium solution to eighty per cent. of
the chloride of magnesium solution.
The mixture thus obtained is mixed with what is known as "bitter earth" (a
form of oxide of magnesia produced in Frankenstein, in Silesia, and known as
"Bittererde" but which may also be obtained elsewhere or may be manufactured
artificially) in the proportion of about fifty-five per cent. of the mixture and forty-
five per cent. of the "bitter earth," in order to form a cement or material for
binding together the grains of emery, diamond, or other hard cutting or abrasive
substance. The proportion of the latter may vary according to its character and
to the particular purposes to which the saw is to be applied.
The cement or suitable cementitious compound and the abrasive material having
been thoroughly and carefully mixed, the mixture is filled into the mould round the
projecting tongue upon the disc which is to form the saw, to which tongue the
mixture very firmly and strongly adheres, the firmness of its adherence being
promoted by the holes in the tongue which it also fills.
When dry, which may be in about 6 to 12 hours, the saw is removed from the
mould, and it may then be soaked in a mixture of petroleum and linseed oil, or
other suitable oil, in the proportion of about half of each, for the purpose of
rendering the cement non-hygroscopic, and the smooth face of the abrasive cement
may then be removed or roughened if desired, by an emery wheel or other
equivalent means.
It is to be understood that my invention consists in the novel method of
applying abrasive material to saws used for sawing stone or other hard material,
and of preparing the metal disc which forms the body of the saw to receive the
material.

page_text: The details, shape, and proportions of the parts of the saw, and of the materials
used to form the abrasive cement may be varied more or less to suit different
circumstances and conditions.
For instance where a cut of considerable width is to be made the abrasive
cement may be applied to a fixed edge of the saw, without the latter having been
first reduced in thickness.
Or, instead of a circular saw, a more or less straight one may be used, the
abrasive composition being applied in the way described to the cutting edge which
is reduced in thickness and provided with transverse holes to receive it.
It is evident that my improved saw may be applied to cutting metals, or other
substances, as well as to stone of different kinds.
The improved saw is very durable, effective, economical, and easily made and
repaired when necessary.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be applied I declare that what I
claim is
-
1. The improved saw, consisting of a metal disc or plate to the cutting part of
which is applied a mixture of grains or fragments of emery, diamond, or other
:sufficiently hard substance, mixed with a cement, substantially in the manner and
for the purpose described.
2. The method of reducing the thickness of the metal disc or plate at the part
where the abrasive material is to be applied, substantially as described and
illustrated.
3. The method of making holes through the part of the metal disc or plate
to which the abrasive material is to be applied for the purpose of ensuring the
adhesion of such abrasive material, substantially as described and illustrated.
Dated this 9th day of December 1893.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.