Improvements in or connected with Grindstones.
Year: 1896

page_text: Date of Application, 4th May, 1890
Complete Specification Left, 29th Jan., 1897-Accepted, 6th Mar., 1897
Date of
ay, Tobu
Complete Specification Left, 29th Jan., 1897-Accepted, 6th Mar., 1897
PROVISIONAL SPECIFICATION.
Improvements in or connected with Grindstones.
I, FRIEDRICH ANTON ZIEGNER, of the Firm of Ziegner and Fritzsche,
Manufacturers, of Klosterstrasse, Chemnitz, in the Kingdom of Saxony, do
hereby declare the nature of this invention to be as follows:-
Natural grindstones have the drawback, that they are generally too soft and
at the same time too coarse-grained, and that their hardness varies at different
parts of the stone.
The present invention has for its object to produce a grindstone which is a good
substitute for the natural grindstones, without possessing their drawbacks.
For this purpose I make a mixture of the following materials.-
Washed sand from sandpits
Chloride of magnesium solution at 35° Beaumé
Magnesite (calcined magnesia)
Gypsum or plaster of Paris
60 per cent.
20 per cent.
- 18 per cent.
2 per cent.
With the pasty mass thus obtained I fill a mould corresponding to the shape and
size of the desired grindstone and allow it to dry.
After the water introduced by the solution of magnesium chloride has evaporated,
the dry stone is taken out of the mould and is ready for use.
Dali uh dan of Max 1806
Improvements in or connected with Grindstones.
I, FRIEDRICH ANTON ZIEGNER, of the Firm of Ziegner and Fritzsche,
Manufacturers, of Klosterstrasse, Chemnitz, in the Kingdom of Saxony, 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:-
Natural grindstones have the drawback, that they are generally too soft and
at the same time too coarse-grained, and that their hardness varies at different
parts of the stone.
The present invention has for its object, to produce a grindstone which is a good
substitute for the natural grindstones without possessing their drawbacks.
For this purpose I make a mixture of the following materials;-
Washed sand from sand pits
-
60 per cent.
Chloride of magnesium solution at 35° Beaumé
-
20 per cent.
18 per cent
Magnesite (calcined magnesia)

page_text: With the pasty mass thus obtained I fill a mould corresponding to the shape
and size of the desired grindstone and allow it to dry.
After the water introduced by the solution of magnesium chloride has evaporated,
the dry stone is taken out of the mould and is ready for use. This stone is
considerably harder than natural grindstones, and its hardness is uniform; in
consequence of which it has not only a sharper "bite," but the material on which
the stone acts will be ground off equally at different places, while the grindstone
wears off very slowly.
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
An artificial grindstone made from washed sand, magnesium chloride solution,
magnesite and gypsum approximately in the proportions described, said materials
being mixed together, and the mixture moulded to the required shape and size.
1007
FAIRFAX & WETTER,
Agents for the Applicant.