AN IMPROVED ROLLER MILL WITH FREE AXLES FOR GRINDING ALL KINDS OF GRAIN, AND FOR BRUISING MALT AND ALL SIMILAR PRODUCE
Year: 1875

page_text: COMPLETE SPECIFICATION filed by Bernhard Demmer at the Office
of the Commissioners of Patents, with his Petition and Declara-
tion, on the 6th December 1875, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BERNHARD
DEMMER, of Vienna, Austria, send greeting.
WHEREAS I am in possession of an Invention for "AN IMPROVED
ROLLER MILL WITH FREE AXLES FOR GRINDING ALL KINDS OF GRAIN, AND FOR
BRUISING MALT AND ALL SIMILAR PRODUCE," and have petitioned Her Majesty
to grant unto me, my executors, administrators, and assigns, Her Royal
Letters Patent for the same, and have made solemn Declaration that
I am the true and first Inventor thereof.
NOW KNOW YE, that I, the said Bernhard Demmer, do hereby declare
that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement :-
This grinding mill is represented by the twelve Figures of the accom-

page_text: In Figures 1 and 2 the rollers care shewn in odd numbers (in this
case 9 rollers) running on a cast iron or wrought frame a, and these
rollers turn in the adjustable bearings b. Each of the end rollers is
provided on each end with belt pullies D keyed thereon, around which
pullies the two endless belts e are attached. By means of these endless
belts all the rollers are pressed equally together, they all turn regularly
if motion is imparted to one or several of them without any pressure of
these belts being borne by the bearings 6, and in which bearings the
trunnions of the rollers have merely got to support their own weight.
The trunnions of the rollers are not dangered in case too large
quantities of the grain to be ground are fed between the rollers, and
the limited elasticity of the belts allow the single rollers to run
naturally against each other, and this elasticity always exists between
the individual pairs of grinding rollers in accordance with the tightness
of the belt.
Motion is imparted to the mill by a driving shaft or a counter shaft
acting on one of the end rollers, and preferably on both ends of this said
roller by means of belts on the pulleys f.
By means of the tightening belts e the driving power is transmitted
to the roller at the other end of the mill, and these two end rollers drive
the neighbouring rollers and thus all the following ones. Besides which
the roller c' is driven by the pulleys 9' and g³ by means of a strap,
also the roller c is driven by means of the pullies 1 and 23 of the
same, and the roller c³ by the pullies u¹ and u³, also by means of a strap.
This arrangement of driving as above described and illustrated in the
annexed Drawing, Figures 1 to 5, can also be modified as circumstances
may require, for instance, direct from two driving shafts or countershafts
in such a manner that the driving force be transmitted direct on each
pair of grinding rollers. The pressure of the rollers against each other
depends upon the tightness of the belts, it is natural that these belts
like all other belts should have to be tightened from time to time, there-
fore wooden or other appropriate pullies m, n (see Figure IV.), can be
placed whilst running on the trunnions 8³, 83, of the middle roller, or of
any other roller near the centre of the mill, and these wooden pullies
are larger in diameter than the driving pulleys d, and in this manner
the slack is taken up (see Figure IV.), or this end may be obtained by
the tightening arrangement which consist in three rollers rotating one
on the other, and which are moved by a screwed connecting rod and

page_text: hand wheel in this manner, also the belt e is tightened more or less,
according to the requirements, and the pressure of the grinding rollers
augmented as required.
Instead of the above arrangements there is represented in Figure VI.
another tightening device which is attached fast on both ends of the
belts e, and thereby tightens directly the belt e by means of the nuts
t and v. The nature of this tightening arrangement will be clearly
understood by the Drawing, Figure VI.; it is merely advisable to remark
that x, y, are hinges which allow the belt to lay unhindered close round
the pullies, whilst the principle of the same consists in the hinges x, y,
and in the bolts of the nuts t, v, whereby the slack is taken up and the
belt tightened. The rollers lay on their axles crossways along the
frame and are adjustable with regard to one another, but still so that
the whole series of rollers need not be adjustable; one of the rollers is
fixed by its bearing to the frame, and in such a way that the rollers can
all be pressed together and still form a close arrangement.
In the accompanying Drawing one of the end rollers is pressed
against the other by means of a screw. When a tightening belt is
made use of the number of rollers must always be an odd one, such
as 3, 5, 7, 9, and so on.
In the accompanying Drawing Figures 1 and 2 nine rollers are
employed. The number of those not directly driven is then always
in this case =4. Over the rollers running in the frame are
situated the usual feed rollers which conduct the grain, etc., to be
crushed or ground to the pair of grinding rollers. The meal adhering
to the rollers after it has passed between them is carried off by a scraper
in the shape of a knife, either immediately from each pair of rollers from
below or from the top after it has passed entirely or partially the next
roller.
The size, diameter, and length of the rollers as well as the number of
the same is undetermined, and depends upon the purpose to which the
mill is to be put.
The rollers can, according to the work to be done, be made of cast-
iron, wrought-iron, steel, chilled cast-iron, glass, bone, porcelain, wood,
etc., and only require as flat a surface as possible. The corn or other
grain to be crushed is placed in the hopper k brought down on the
rollers c by the regulating feed rollers w, pressed, and falls thence in

page_text: the box, from which the crushed material is discharged by the
opening lor carried further on. The pressure of the rollers one on
the other can be produced by any kind of belt, strap, rope, wire, cable,
or metal band, and in general by any material which has an elastic
action.
In Figures 8 and 10 a machine is represented with two freely rotating
rollers. Instead of the tight belts which can be dispensed with in this
mode of construction, on each side or both end rollers are adapted two
bevil cones », r, or cylindrical rollers v, v. The conical or cylindrical
drivers d², d³, d³, or e¹, e², e³, mounted on the respective shafts ƒ¹ and ƒ³,
by their rotation in contact with the above-mentioned cones or rollers
impart their motion to the latter without much slipping; d², d², and d³,
are keyed on their shafts f¹ and f², whilst those e¹, e², e³, which run in
the bearings g, g, g, are fixed in such a manner with the key way on the
shafts ff, that the shafts can be pushed longitudinally through the
drivers rotating in the bearings g, g, by means of a spring. The shafts
ff, are also free to move londitudinally in their bearings h, h. At
that end where the shafts f¹, fa, can be moved longitudinally in the
drivers e¹, e, e³, are two springs 1, 2, of any appropriate system mounted
in such a manner that they can be set more or less by means of the
nuts m, n, or any other mechanical means, such as a wedge or a key.
In the above-mentioned Figures volute springs are shown; instead of
these any other metallic springs of any other system, or india-rubber or
equally elastic material, may be used in such a manner that any elastic
pressure can be obtained. By means of the springs 1, 1, or any other
appropriate elastic means, the shafts f', f, with the drivers d', d³, d³, or
the conical pulleys e¹, e², e³, as required, are pushed against the moveable
flat or taper pullies on the shafts, and thus the whole series of rollers
are pushed against each other with the same pressure of the spring or
any other elastic means employed. The distance apart of the rollers is
regulated by the tightening belts, Figures 1, 2, 4, and 5, or by the
elasticity of the aforesaid springs, or by any other appropriate means
with a view of properly grinding or bruising the grain, and of allowing
any unforseen obstacle to pass. Power is transmitted to the mill by
the driving belt running on the pullies o, p. The number of the rollers
must in this construction always be an even one.
All that has been said relatively to the manner of tightening in.

page_text: BERNHARD DEMMER. (L.S.)