Grinding Grain and like Substances:
Year: 1887

page_text: Grinding Grain and like Substances:
I JAMES DONALDSON of No. 17 Water Street Liverpool in the County of Lancaster
Engineer do hereby declare the nature of my invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the following
statement:
The object is to provide Roller Mills used for reducing and grinding grain and like
substances with advantages, as regards strength and steadiness and with means for the
better regulation of such machines..
With Roller Mills containing two pairs of grinding rollers my invention consists
in joining the end framing by means of a deep girder placed longitudinally and
centrally thus forming a solid back bone to the machine and making the framing a
strong rigid structure.
In Roller Mills used for grinding grain and similar substances, usually one roller
of each pair runs in fixed bearings while the other is free to yield owing to its bearings
being held in position by springs, generally the movable bearings are attached to arms
or levers pivotted on fulcrum pins the free ends of these levers abutting against or
resting upon springs, through which pressure is applied, these levers also hear against
or upon an eccentric used for the purpose of throwing the rollers apart, by hand
or otherwise.
Such arrangement is defective, in-as-much, as a variable pressure is produced, by
extension or compression of the springs when the moveable roller is adjusted, nearer
to, or further from the other roller. Moreover, as the rollers rest directly through-
their bearings and levers upon the elastic springs, vibration is produced, which is
detrimental to the operation of grinding.
To obviate the above evils, I use Auxiliary levers, in combination with the ordinary
levers or arms carrying the moveable rollers, and pivotted or hung upon the same
pins, or pins adjoining those supporting the Roller levers, or these pins may be
placed in other positions as required for the convenience of framing and class of
Roller Mills.

page_text: The Auxiliary levers I place so that the Eccentrics are clipped or held tightly
between them and the ordinary levers. Each pair of levers being held together by
a bolt or its equivalent passing through holes in both. The head of the bolt bears
against the outside of one lever, while the spring strung upon the bolt presses against
the outside of the other lever, the point of the bolt is screwed, to receive an internal
screwed hand wheel or nut.
The hand wheel and screw is used for the purpose of compressing the springs and
regulating the pressure applied to the grinding rollers, or any other convenient means
may be used to compress the springs, or the springs may be arranged to be extended.
Thus when the rollers are thrown apart by means of the eccentric, both levers move
simultaneously and equidistant, the bolt, spring, and hand wheel, travelling with them,
consequently the compression of the spring remains unaltered, and the pressure
constant. At the same time when the rollers are pressed apart by hard substances
passing through between them, the springs are free to yeild.
Also as the roller lever is held hard up to the Eccentric, by the bolt and Auxiliary
lever, it has a solid base to rest upon, and vibration is prevented when the grinding
rollers are working.
Another part of my invention is as follows, For the better regulation of the
quantity of material admitted to the feed rolls, In place of a slide on the feed hopper,
as usually adopted, I use a peice of round bar iron or shaft, with bearings at each
end, placed over and of the same length as the feed roll, and of about two inches in
diameter, the end journals are turned down out of the centre, to about one inch
diameter, thus forming an Elongated Eccentric sheave of the same length as the feed.
roll, with a throw of about one inch. On one of the journal ends, and between the
inner end of its bearing, and the end of the eccentric sheave, I place a loose collar,
and on the prolonged end of the journal, at the outer end of its bearing, a hand lever,
sliding upon a Key let into the shaft. The extreme end of the shaft is screwed, to
receive a winged nut, which, when tightened up draws the eccentric and loose collar
forward against the end of the bearing, thereby fixing the eccentric in any desired
position.
Thus by using the hand lover, winged nut and eccentric, the slit over the feed roll,
admitting the feed, can be quickly and accurately set, and fixed, by a simple move-
ment, to any desired width of opening.
The apparatus before described, may be used, either in the construction of New
Roller Mills, or applied to existing Roller Mills, Such Roller Mills may be of the
one pair, two pair, or the three high roller type, and may be driven by belt, or belt
and gearing combined.
DESCRIPTION OF THE DRAWINGS.
Fig. 1, is an end Elevation, and Fig. 2, is a front view, partly in external Elevation
and partly in Section, of a double or two pair roller mill, having my improvements.
The Roller Mill contains two pairs of grinding rollers A A, AA, the framing
is composed of the end frames B. B. supporting the rollers, The brackets C. C.
carrying the feed rolls and hopper-the deep girder D. bolted to the framing B. and
brackets C, binding them rigidly together, thus forming a central web or back bone to
the structure.
The inner grinding roller A of each pair, runs in fixed bearings, while the outer
-roller A¹, runs in bearings, carried on levers E, pivotted on fulcrum pins F, fastened
to the framing, the free ends of the levers E abut against the eccentrics G, keyed on a
shaft, which is supported by bearings in the framing. On the opposite side of the
eccentrics are placed the auxiliary levers H, hung from the pins F in juxtaposition to
the, Roller levers E, bolts pass through holes in levers H and E and binds them
close to the eccentrics G, with a strain equal to the pressure put upon, the springs J.
by the hand wheel K, screwed upon the ends of the bolts . Thus it will be seen
that when the eccentrics are turned parily round, by means of the hand lever L keyed
on the eccentric shaft ', for the purpose of adjustment or for throwing the rollers

page_text: apart, no additional compression is put upon the springs J, as they, the bolts, hand
wheels and auxiliary levers H, iravel with the roller levers E.
Fig. 3, represents a modification of the Auxiliary levers H, in the same combination
of mechanism as before described-for use with Roller Mills having one pair or two
pair of rollers.
Fig. 4 shows an adaption of the combination in which the Auxiliary lovers H, are
made shorter, than the roller levers E, and are pivotted upon pins fixed in the framing,
on the opposite, side of the eccentrics to that in which the roller levers E are pivotted,
by the use of which, the advantage is gained of relieving the compression and
pressure upon the springs J, when the rollers are thrown apart, by partly rotating
the eccentric.
Fig. 5 shows the combination of levers, eccentrics and springs with the Auxiliary
levers H, as applied to rollers in superposed bearings-in this case it is necessary to
use two arms or bell crank levers, and consequently two Auxiliary levers H, to each
moveable roller, One eccentric at each end of the machine bears against the ends
of the four levers, the action being the same as described in the case of Figs. 1 and 2.
In Figs. 1 and 2, Mis the feed regulating eccentric bar or sheave, with reduced ends or
journals N turning in bearings O. The said feed regulating bar is actuated by the
hand lever 1, which is free to move longitudinally on a loose fitting key, Q is a loose
collar, on the neck between the bearing and end of eccentric sheave, R is a winged nut,
screwed on to the end of the shaft or journal.
The Elongated Eccentric sheave M, is placed on the front of the feed hopper, over
the feed roll, with its throw towards, and nearly touching the feed roll, when the feed
is shut off. If the eccentric sheave be turned outward, away from the feed roll, by
the hand fever P, the distance between the sheave and the feed roll will be increased,
one fourth of a revolution having been found sufficient, when the throw of the eccentric
sheave is about one inch-The eccentric sheave is fixed in the desired position, by
screwing up the winged nut R, which draws the Eccentric M. and loose collar Q hard
up against the end of bearing O.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed.-I declare that what I claim is―
First: The combination, with the frame of rollor mills having two pairs of rolls;
of a deep web girder, substantially in the manner and for the purpose set forth.
Second: The combination of Auxiliary levers H. Roller levers E. Springs J. Bolts h.
Eccentrics G. and hand wheel K. for the purposes set forth.
Third: The combination of the elongated Eccentric M. hand lever P. winged nut R.
and loose collar Q for the purposes set forth.
Fourth The combination in Roller Mills of two or more of the improvements
herein set forth.
J. T. KING,
Agent for the Applicant.