Improvements in the Manufacture of Emery Wheels, Grindstones, Hones, Millstones, and the like.
Year: 1893

page_text: Date of Application, 27th Feb., 1893-Accepted, 2nd Sept., 1893
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Emery Wheels, Grindstones,
Hones, Millstones, and the like.
:
I, OLAF TERP of Parkfield House, Perry Vale, Forest Hill, in the County of
Surrey, 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 :-
My improvements refer to emery wheels grindstones, hones, millstones, and the
like in which the emery, corundum, or other granular material is bound together
by a cement or cementitious material. For the purpose of my invention I make a
saturated solution of chloride of calcium crystals, about equal proportions by weight
of the chloride and the water. I also make a saturated solution of chloride of
magnesium crystals about 66 per cent. by weight of the chloride and 34 per cent. of
the water. Of these two solutions I make a mixture the average proportion of
same being about 20 per cent. by weight of the chloride of calcium solution to
80 per cent. of the chloride of magnesium. The mixture solution thus obtained I
mix with bitter earth about 55 per cent. of the former to 45 of the latter to form a
cement or cementitious material which I employ for binding together the emery,
corundum or other granular material to form emery wheels, bones, grindstones,
millstones or the like. The quantity of cement to be employed will vary according
to the granular quality of the material. Thus for instance for coarse emery No. 12
I use about 25 per cent. by weight of the cement to 75 of the emery whereas for
finer grades of emery more cement is required.
The materials having been carefully mixed I put it in moulds of the required
size and form and when dry, that is to say, after some 6 to 12 hours according to
the size and character of the moulded article and the state of the weather I remove
it from the mould and soak it in a mixture of petroleum and linseed oil, or other
suitable oil soluble in petroleum about half of each for the purpose of making
it nonhygroscopic; this will take about 5 to 12 hours according to the size and
character of the moulded article. I then grind off the thin smooth outer skin or
glaze of the article by means of an emery wheel or grindstone and water.
As regards the aforesaid mixture of chloride of calcium solution and chloride of
magnesium solution the proportions stated are average but they will depend
somewhat upon the purpose for which the emery wheel or other article is to be
used. For operating upon soft metals such as brass the amount of chloride of
magnesium solution should be decreased and that of the chloride of calcium
increased; the variations being however within the limits of 10 of the calcium
chloride solution to 90 of the magnesium chloride solution and 30 of the former
to 70 of the latter.
My invention is also applicable to emery wheels and other similar articles made
with a core of a cheaper material but instead of the usual wood core which is
objectionable especially for high speed of rotation when the outer part
apt to
separate therefrom and fly off in pieces I make the core of sand or other cheap
material bound together with my aforesaid cement, while the outer part of the
article is made with the emery or other grinding material.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The application and use for emery wheels, grindstones, hones, millstones and
the like of the cement or cementitious material hereinbefore described to the
cementing together of emery, corundum or other granular material.,

page_text: 2. The process of manufacture of emery wheels, grindstones, hones, millstones
and the like substantially as described.'
3. The improved emery wheels, grindstones, hones, millstones and the like made
as described.
1
4. The improved cored emery wheels, grindstones, hones, millstones and the like
made as described.
Dated this 27th day of February 1893.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.