IMPROVEMENTS RELATING TO ARTIFICIAL STONES FOR GRINDING AND SIMILAR PURPOSES, AND DESIGNED TO INCREASE THEIR RESISTANCE TO CENTRIFUGAL FORCE
Year: 1878

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS RELATING TO ARTIFICIAL STONES FOR GRINDING AND SIMILAR
PURPOSES, AND DESIGNED TO INCREASE THEIR RESISTANCE TO CENTRIFUGAL
FORCE." A communication from abroad by Emile Eugène Albert. Sorel, of
Paris France.
Sealed the 12th July 1878, and dated the 30th January 1878.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 30th January 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS RELATING TO ARTIFICIAL
STONES FOR GRINDING AND SIMILAR PURPOSES, AND DESIGNED TO INCREASE THEIR
RESISTANCE TO CENTRIFUGAL FORCE." [A communication from abroad by Emile
Eugène Albert Sorel, of Paris, France.]
This Invention relates to improvements in artificial stones for grinding and
similar purposes, and is designed to increase their resistance to centrifugal force.
The only means heretofore employed for this purpose consists in the use of a
small ring of round iron placed within the stone near the centre thereof, and
the diameter of this ring has rarely exceeded the fourth of that of the stone.
It has been found in practice that this method is very inefficient. In most cases
the material of which the stone consists does not adhere properly to the ring, and
a gap is created which weakens the stone at the centre, and becomes a cause of
rupture.
Attempts have been made to, remedy this defect by making the rings too weak,
but the result has been that the ring and stone have both broken.
My said improvements rest upon the following hypothesis, that is to say :-If,
instead of employing an interior ring, the stone is surrounded on its circumference
by a very strong ring no rupture would be possible at the speeds usually employed

page_text: in practice. This method would be the best, but in many cases it is not suitable,
inasmuch as the use of the edge of the stone would thereby be prevented; therefore
in carrying my said Invention into practice, I adopt the principle of this method
as far as practicable.
In applying my said Invention to a stone fifty centimeters in diameter, one of the
faces of the said stone is swelled or extended, the said extended part being, say,
about three hundred and fifty millimeters in diameter, by ten millimeters in thick-
ness, and then I surround this swelled or extended part by a ring of square iron of
suitable strength. The said extended part increases the power of resistance of the
stone, and the ring which is placed around will maintain the whole of the portion
which it embraces, that is to say, the extended part described as having a diameter
of about three hundred and fifty millimeters; moreover the mass of the stone beyond
the said ring not being very considerable, it may be said that the whole of the
stone will be maintained unless a very high speed should be given to it.
When the stone becomes worn as far as the said ring, the latter will be removed,
and the stone may continue in use without it.
In the case of stones of larger size two or more rings may be used, placed in such
positions that when the stone is worn as far as one of the said rings, the other ring
will maintain the remainder. The strength of the rings will be proportioned to the
size of the stones.
In some cases it may be found that the swelled or extended part of the face of
the stone would be inconvenient for mounting the latter or for the work which has
to be performed; therefore, in such cases I should place the ring within the stone
but level with the faces of the same. This latter arrangement is not so good as my
herein described other method, but will be found sufficient for the desired purpose,
as it keeps the stone at great distances from the centre.
Although I have described the rings as being made of square iron, I may also
construct them of any other suitable sections.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 30th
July 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS RELATING TO ARTIFICIAL
STONES FOR GRINDING AND SIMILAR PURPOSES, AND DESIGNED TO INCREASE THEIR
RESISTANCE TO CENTRIFUGAL FORCE." A communication from abroad, by Emile
Eugène Albert Sorel, of Paris, France.
This Invention relates to improvements in artificial stones for grinding metal
surfaces, sharpening tools, and similar purposes, and is designed to increase the
resistance of such stones to centrifugal force and prevent their rupture by the action
of the same.
Various means have been heretofore employed for the purpose of increasing the
resistance of such stones to the action of centrifugal force, but it has been found in
practise that none of them are thoroughly efficient.
My said improvements are, based upon the following hypothesis, that is to say :-
If the stone is surrounded on its circumference by a strong ring or hoop no rupture
would be possible at the speeds usually imparted to such stones. But this manner
of applying or arranging the said ring, although the best theoretically, in many
cases is not practicable, inasmuch as it would prevent the use of the edge of the
stone; therefore, in carrying my said Invention into practice, I adopt the principle
of this method as far as practicable.
The said Invention is illustrated in the accompanying Drawing, which shews in
transverse section three examples of stones, provided with my improved means for
preventing their rupture by centrifugal action.
In applying my said Invention, as shewn in Figure 1, to a stone of fifty centi-
metres in diameter, one of the faces or sides of the said stone is formed with an
extended part or projection, the said extended part being, say, about three hundred
and fifty millimetres in diameter by ten millimetres in thickness; I surround this
extended part or projection by a ring A of square iron of suitable strength. The
said extended part or projection itself increases the power of resistance of the stone,
and the ring thus placed around or added to it will maintain or hold the whole of
the portion which it embraces, that is to say, the part of the stone within a diameter
of three hundred and fifty millimetres, and the mass of the stone beyond the
said ring not being very considerable, it may be assumed that the whole of
the stone will be held unless an unusually high speed should be given to the
same.
When the stone is worn down to the ring A, the latter will be removed, and the
stone may continue in use without the said ring.
In the case of stones of larger size two or more rings A, B, as shewn in Figure 2,
may be placed in such positions that when the stone is worn down to the ring A,
the other ring B will hold the remainder of the stone. The strength of these rings
will be proportioned to the size of the stones.
In some cases it may be found that the above-described projection or extended
part of the face of the stone would be inconvenient for mounting the latter, or for
the work which has to be performed; therefore, in such cases. fit the rings A, B,
within grooves or channels in the stone, but flush or level with the faces of the
same, as shewn in Figure 3. This arrangement may not be so advantageous as the
others herein-before described, but will be found very efficient for the desired
purpose, and it has the advantage of affording support to the stone at great distances
from the centre of the same.
Although I have described the aforesaid rings as made of square iron, I may
construct them of other suitable sectional forms, and of any suitable material.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood

page_text: that I claim, the means for increasing the resistance of artificial grinding stones to
the action of centrifugal force, consisting in the application to the said stones of
the ring or rings, as above set forth, and as illustrated in the Drawing.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Thirtieth day of July, in the year of our Lord One
thousand eight hundred and seventy-eight.