AN IMPROVED MILLSTONE
Year: 1882

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, Lake,`
and Co, Patent Agents, Southampton Buildings, London, for an Invention
"
of "AN IMPROVED MILLSTONE Communicated to him from abroad by
Pierre Vérat, of Paris, France, Merchant.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 4th November 1882.
WILLIAM ROBERT LAKE, of the firm of Haseltine Lake and Co, Patent
Agents, Southampton Buildings London "AN IMPROVED MILLSTONE" [A com-
munication to him from abroad by Pierre Vérat, of Paris, France, Merchant.]
This invention has for its object to provide an improved millstone for grinding
corn, the chief characteristic of the said millstone being the conformation of its
distributing or feeding grooves which are made of unequal width and depth, that
is to say wider and deeper near the eye or aperture of the stone than at the
circumference.
"
This special form of the grooves of the millstone regulates the carrying surface of
the millstones, and distributes the corn to the rubbing parts which serve to convert
the corn into flour,
Another feature of the improved millstone is that the frictional surface is
straight, without entrance to the centre of the millstone.
The corn is supplied in the ordinary manner by the aperture or eye in the centre
of the millstone, and enters between the stones by the feeding grooves. As these
grooves are larger at their entrance in the centre than at the circumference, the
grain enters more easily into the said grooves than heretofore; these grooves also
proportion the rubbing part of the millstone. Moreover a greater quantity of cold
air enters the grooves with the corn than in the ordinary millstones, and prevents
the heating of the millstones. The flour does not become heated and the stones
perform a greater amount of work and require dressing less frequently than those
heretofore employed, and do not require much motive force

page_text: This stone is intended to revolve towards the left and the grooves are placed in
a regular manner so as to distribute the grain all over the stone, and introduce a
large amount of air, sufficient to prevent the heating of the grist even without the
help of aspirators or exhausters which are generally employed with millstones. As
will be easily seen, this mode of constructing millstones differs greatly from those
heretofore adopted. The improved millstone presents a uniform section formed by
stones joined together and all of one kind and not of different kinds as in English
millstones between the grinding part and the centre; it has a thoroughly level
surface well dressed and without any inclination or dip towards tho centre for the
introduction of grain.
The diameter of the eye O may be varied but should be as sinall as possible.
The rubbing or grinding parts commence their work near the eye O and thus offer
a working surface superior to that of other millstones. Under these circumstances
it might be supposed that this stone would require more motive power than
ordinary millstones. On the contrary, however, the heaviest part of the work.
being performed at the point where the grain enters the first grooves, in the
millstone the greatest resistance is offered at a distance of from eight to twelvo
centimeters from the axis, whereas in ordinary millstones it is offered at a distance
of about from forty seven to fifty centimeters from the axis; there is therefore in
the present case five times less resistance, the same motive power being used in
each case.
The grist obtained by the grinding with the millstones thus improved comes out
in a drier state than from other millstones, while retaining its tepid and cotton
like feel. The flour made from this grist is also superior to that obtained by other
millstones for it is well known that in practice, if the feeding of the grain to the
millstones is insufficient, the grist comes out with a dull colour is deficient in gluten
and has a strong odour of silex if on the contrary the feeding is too rapid the
stoDes get hot and the grinding is effected by pressure the gluten being moreover
impaired. The best grist and that richest in gluten is therefore that which is
produced in the greatest quantity provided it does not get heated and the work is
properly finished, and this result is obtained by the improved millstone herein

page_text: described. The grooves may be straight curved or of other suitable shape but
straight grooves are preferable as being more easily hollowed out, distributing the
grain better and during the grinding crossing each other well, at various angles in
a manner similar to the action of a pair of shears.
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
that I claim
The improved millstone having as its distinctive features the following, that is
to say:
First. The widening and deepening of the grooves towards the eye of the stone,
which facilitates the introduction of a large quantity of air with the grain and
permits aspirators or exhausters to be dispensed with.
Second. The augmentation of the rubbing parts and their distribution over the
entire surface of the stone instead of only a portion thereof.
Third. The augmentation of the work obtained with the same motor by reason
of the point of resistance being arranged near the centre instead of at a distance
therefrom as heretofore practised.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this fourth day of May in the year of our Lord one thousand
eight hundred and eighty three
TU
TAR