IMPROVEMENTS IN REDUCING OR GRINDING MACHINERY, CHIEFLY DESIGNED FOR THE MANUFACTURE OF FLOUR."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 23rd August 1880. A communication
from abroad by Wilhelm Seck, of Bockenheim, Germany.
"
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. IMPROVEMENTS IN REDUCING OR GRINDING
MACHINERY, CHIEFLY DESIGNED FOR THE MANUFACTURE OF FLOUR." [A com-
munication from abroad by Wilhelm Seck, of Bockenheim, Germany.]
This Invention relates to improvements in machinery for crushing or bruising and
grinding corn, and of that class in which three rollers are arranged one above the
other, the two outer ones of which are pressed against the central roller by means
of levers and friction rollers in order to relieve the bearings of the rollers from
pressure.
The first part of the present Invention consists in the special construction of the
levers by which the pressure of the rollers is effected, and in the arrangement of
auxiliary levers by which, in combination with a set-screw and an excentric, a
perfectly even parallel position of the three rollers as well as the diminution and
the entire taking up of the pressure is obtained in a very simple and easy
manner.
The second part of the present Invention consists in employing the axle or shaft
of upper friction rollers as a feeding roller, whereby a prompt stopping of the feed
is obtained as soon as the pressure upon the reducing rollers ceases, for the reason
that the friction rollers and the shaft serving as a feeding roller, which are firmly
connected, are stopped immediately.
The third part of the present Invention consists in the application and con-
struction of a scraper, which is not in a single piece as the scrapers heretofore used,
but is made of several separate narrow springs, placed side by side. This con-
struction has for its purpose to keep the rollers clean from incrustation in a
better manner than has been heretofore possible without requiring too great
pressure, which is apt to cause heating of the rollers. In using a scraper made in
one piece the pressure by which it bears against the roller for keeping the latter
clean must be so considerable that the roller frequently becomes hot in consequence

page_text: of the friction. This defect is obviated by using a scraper composed of several
blades, whereby the pressure upon the roller is considerably diminished. This
improved scraper may be also used in roller-mills of any other construction than
that to be hereinafter described.
In carrying the said Invention into practice I provide three grain reducing
rollers whose axles or shafts are provided with bushes sliding in guides in standards.
Upon the axles or shafts of the upper and lower reducing rollers I place small
rollers close to the bushes and between the latter and the ends of the reducing
rollers. Friction-rollers of a considerably larger diameter press against the surface
of these small rollers, and are fixed by keys on their shafts. The outer ends of
these shafts are journalled in the ends of four angle levers, two of which have their
fulcrum on one standard and the other two on the other standard.
Each of these levers rotates on a pin, and the shorter arm of each lever carries a
head, serving as a bearing to receive the end of the friction-roller shaft. Upon the
longer arm of each lever there is fixed an auxiliary lever by means of a bolt. One
end of this auxiliary lever is in contact with an excentric, and the other end bears
against a set screw. Upon the lower end of the long arm of the main lever a screw
bolt is suspended or otherwise attached so as to have sufficient freedom. This
screw bolt passes through a boss of the standard and carries a strong spring placed
thereon, which fits into a recess of the boss and serves to produce pressure upon the
rollers.
One arm of the auxiliary lever being, as above stated, in contact at one end with
a set screw, and at the other end with the excentric, may be more or less firmly
pressed against the latter by means of the said set screw. By these means the
position of the first named or main lever may be changed, as well as the tension of
the spring. Each auxiliary lever has arms of unequal length, so that on the
rotation of the excentric the spring is operated accordingly. In consequence of
this the movement of the excentric is produced in an easier manner than would
otherwise be the case.
Upon each standard the ends of the longer arms of the two levers on the same
are turned towards each other, so that the extremities of the two auxiliary levers
bear against the same excentric. For this purpose the auxiliary levers are cut out
at the parts where they come in contact with the excentric to provide means for
bringing them in one line. On both standards there is the saine arrangement of
levers and a similar excentric, which is fixed on a shaft going through both the
standards and carrying the other excentric also. It will be seen from this arrange-
ment that by causing the shaft of the excentric to make half a revolution the four
chief levers arc simultaneously moved to the extent of the stroke of the excentrics,
consequently the friction rollers connected with these levers are at the same time
moved towards or away from the grain reducing rollers according to the leverage
exerted by the lever-arms.
If it is considered that by the use of the two auxiliary levers each one of the
principal levers may be separately adjusted by means of the set-screws without
changing the position of the point of contact with the excentric.
The great
advantage of this arrangement will be apparent, as provision is thus made for
adjusting the four friction-rollers most accurately by means of the set screws afore-
said, so that the grain reducing rollers must be in an exactly parallel position. The
pressure of each spring may then be regulated by means of nuts so as to cause the
four springs to exert the same amount of pressure, the auxiliary levers remaining
in contact with the excentric during all this time. After having carefully adjusted
this roller-mill when it is first set up the excentric shaft requires only to be turned
round for 180 degrees during the operation, in order to be able to change the
pressure upon the grain reducing rollers up to that point when no pressure will be
exerted upon the said rollers. When the excentric is rotated for 180° the two
upper friction rollers move entirely away from the small rollers, and as the pressure
ceases they stop, and with then the shaft, which serves as a feed roller. It follows

page_text: therefore that the feed ceases at the same moment that the pressure upon the
grain-reducing rollers terminates.
By using the shaft of the upper friction rollers as a feed roller not only is the
construction of this roller-mill considerably simplified, but the great advantage is
obtained that the feed ceases at the moment when the pressure on the rollers is
removed by turning the excentric; consequently the arrangement according to this
Invention forms an important improvement. The removal of the pressure from
the rollers and the stopping of the feed are operated by one movement of the lever.
The lever provided for this purpose is fixed on the excentric shaft, and is provided
with a curved guide and with a device for adjusting or setting it as may be
convenient.
The advantage of stopping the feed when the grain reducing rollers are relieved
fron pressure is a very important one, for if the feed were not stopped immediately
when the pressure on the grinding rollers ceases some of the material to be ground
would be admitted to the rollers after they stop, and this material would not be
reduced or ground; also when accidents occur, caused by particles of iron or stone
getting in between the rollers, or by any other circumstances, this sudden and
simultaneous stopping of the pressure upon the rollers and of the feed is of great
importance.
My improved scraper is constructed in the following manner, that is to say:-I
make the same of a series of thin blades or plates of steel (such as ordinarily used
for watch springs), which I place side by side and clamp between two bars of iron.
These plates or blades are placed so closely to each other that they form a
continuous uninterrupted row. In consequence of the great elasticity of this
scraper, the pressure by which the steel plates are pressed on the rollers for the
purpose of keeping the rollers clean may be much slighter than that required for
scrapers made in one piece.
To obtain good results with a roller-mill for producing flour it is absolutely
necessary that the rollers should be kept free from glutinous incrustations formed
either in imperceptible, almost microscopical, holes or grooves which may exist in
the rollers, or when particles containing fat or resin are crushed or bruised between
the rollers, such as particles of the germs of corn. In this case a crust is formed
at such places, which crust if not immediately removed continues to increase in
thickness and extent as the rollers work, and finally becomes so firm that there
will be considerable difficulty in scraping it off. Such a crust once formed soon
becomes a ring or envelope surrounding the roller. As soon as this (envelope is
formed the efficiency of the rollers is completely destroyed as the incrustation
separates the two rollers, so that the fine groats or particles can pass without
becoming bruised or crushed. When the formation of this glutinous crust is to be
prevented by scrapers, the blades of which consist of one single piece, a propor-
tionately great force must be exerted to press the scraper against the roller, for
otherwise the crust deposited upon the rollers, say, in a small groove originated by
wear, would lift the scraper along its entire length. In consequence of the great
pressure exerted with such scrapers they get hot (as well as the rollers), and the
amount of power required increases in a considerable degree.
In the use of my improved scraper consisting of several plates or blades, these
plates are individually capable of entering the cavities or inequalities of the roller
which may be produced by wear in the course of time; as the pressure with which
these independent blades of the scraper are to be pressed against the rollers can be
so much reduced, the rollers are not worn away so soon, and even if they were so
worn they would be fit for grinding for a longer time than would be the case if a
scraper made of one piece were used, requiring the rollers always to be of a
mathematically exact cylindrical form.
If a scraper with independent plates or blades is used the rollers will not require
to be turned to a perfectly cylindrical form till the cavities are so great that the
grinding process would be impaired thereby. The bars, between which the steel

page_text: plates or blades are inserted, are secured together by means of screws. One of the
bars is provided with flaps bent rectangularly, by means of which the bars are
attached to the sides of the frame of the apparatus by screw bolts. This fastening
permits in the most simple manner the changing of the angle or inclination of the
scraper plates or blades with regard to the rollers, and for adjusting the plates or
blades of the scraper nothing is required but to loosen the screws. For this
purpose the flaps of the bars are provided with elongated holes, through which the
said screw bolts pass.