Improvement in and Connected with Artificial Millstones or Burrs.
Year: 1885

page_text: Improvement in and Connected with Artificial Millstones
or Burrs.
I, EMANUEL IGNAZ HELLER,. Manufacturer of Iglau, Austria, Hungary, do
hereby declare the nature of this invention to be as follows:-
These artificial millstones consist:
1) of grains of sharp-edged broken quartz, crystal quartz, or Naxos emery, in
different shapes of grain and proportions of weight, according as a fine, coarse, soft,
ordinary or better quality is to be produced.
2) of magnesit or dolomit or another known solid mineralic binding substance.
3) of dissolved chloride of magnesium or soluble glass or a similar known liquid
chemical binding substance.
These three mentioned constituents may be mixed in various quantities of
weight, according as a fine, coarse, hard, soft, dense or porous material is intended
to be produced, and according as ordinary quartz-or crystal-quartz-or Naxos
emery grains are applied, three different qualities of stone are produced.
These constituents are so mixed, that each grain comes in contact with magnesit
or dolomit or another known and suitable binding substance, and with chloride of
magnesium or soluble glass or another known and suitable binding material,
whereby a cementing is produced.
By the addition of the said liquid binding substance, such as chloride of
magnesium and soluble glass, which may amount to 12 to 30 per cent of the entire
weight of the mineral grains and pulverised binding substance according to the
weather being dry or wet, the whole binding substance remains so in contact with
the grains, that the interstices, formed by the sharp-edged grains, are not filled
with cement by stamping or pressing, but remain open.
After this process the burrs are formed in the following manner by means of
special moulds, shown by the drawing.
For mill stones without ventilation tubes, the mould A BCP is filled with the
prepared material, which is subsequently stamped or pressed. For millstones with
automatic ventilation, the cores E are put into the mould ABC P. These cores
may be arranged in various forms (straight, or curved) and positions and may be
TD 71

page_text: made of wood, iron, porcelain etc. Instead of the cores E, tubes of any suitable
material may be employed, which remain in the stone, or the automatic ventilation
tubes may be cut into the finished burr in various forms.
After the mill stone has been formed, the material remains in the mould,
until it becomes compact, that is to say stone hard, whereupon it is removed
from the mould.
Above each tube a hood is fixed to the burr, and according to the direction of
rotation of the burr, cool air can be supplied to the grinding surface from outside,
or the warm air produced by the friction of the burrs can be sucked off.
In the annexed drawing A is the formplate, B the outer mould, C the inner
mould, D the support, E the core for producing the ventilation tube, L the air
channel, P the axle; M are the ventilating hoods.

page_text: After the millstone has been formed the material remains in the mould until it
sets and becomes as hard as stone when it is removed from the mould.
Above each tube a hood M is fixed to the burr as shown in Fig. 2 and according
to the direction of rotation of the burr cool air from without can be supplied to
the grinding surface or the heated air produced by the friction of the burrs can be
sucked off.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is;-
1. For forming millstones and burrs the combination of broken quartz, crystal
quartz and naxos emery, with a solid mineral binding substance such as magnesite
or dolomite, together with a liquid binding substance such as soluble glass or a
solution of chloride of magnesium substantially as described.
2. In millstones and burrs the combination of the ventilating tubes L with
hoods M substantially as described and illustrated and for the purpose set forth,
DL1 AL: Tier 1
1000