IMPROVEMENTS IN AND RELATING TO THE DRIVING OF ROLLERS OF ROLLER MILLS FOR CRUSHING OR GRINDING, AND IN APPARATUS FOR PROTECTING THE SAID ROLLERS FROM THE ACCIDENTAL INTRODUCTION OF IRON PARTICLES BETWEEN THEM."
Year: 1881

page_text: LETTERS PATENT to Pieter Van Gelder, of Liverpool, in the County of
Lancaster, for an Invention of "IMPROVEMENTS IN AND RELATING TO THE
DRIVING OF ROLLERS OF ROLLER MILLS FOR CRUSHING OR GRINDING, AND
IN APPARATUS FOR PROTECTING THE SAID ROLLERS FROM THE ACCIDENTAL
INTRODUCTION OF IRON PARTICLES BETWEEN THEM."
PROVISIONAL SPECIFICATION left by the said Pieter Van Gelder at the
Office of the Commissioners of Patents on the 15th March 1881.
PIETER VAN GELDER, of Liverpool, in the County of Lancaster. "IMPROVEMENTS
IN AND RELATING TO THE DRIVING OF ROLLERS OF ROLLER MILLS FOR CRUSHING
OR GRINDING, AND IN APPARATUS FOR PROTECTING THE SAID ROLLERS FROM
THE ACCIDENTAL INTRODUCTION OF IRON PARTICLES BETWEEN THEM.”
In driving roller mills for grain crushing it is usual to drive the two rollers at
different speeds by means of spur gearing, and as this causes great friction the
rollers soon wear. If therefore the teeth are correctly geared to the pitch line,
in a short time (in taking up the wear) they become closer and useless. They are
therefore geared at start so as not to interlock to a true pitch line. The result is
knocking and a fearful noise, and further a tendency is induced in the rollers to
wear unequally and into flats.
Now my Invention consists in running all the rollers by chain gearing, the
roller shaft carrying wheels or discs with projections to fit the chain and hold into
its links, these wheels being much within the rolling circles of the rollers, so as not
to come in contact even after much wear of rollers. If there are four rollers, say,
the chain passes over one wheel, under its companion, over the next, under the
next, then round a guide or driving wheel, or both, back to the start.
The guide wheel can be made adjustable to take up slack. In the mills with
three rollers the chain goes over a wheel on the top roller shaft round to the other

page_text: side of the wheel on the middle or driving roller shaft, then round the opposite
side of the wheel driving the bottom roller, and so back to the wheel of the top
roller, the guide wheel being dispensed with. This apparatus is applicable for
both mills with equal and mills with differential speed.
The second part of my Invention consists in a simple apparatus for protecting
the rollers from the intrusion of iron particles, and consists in placing in the upper
side of the spout leading into the mill a door that will lift up by hinge or otherwise,
and in this door I fix a series of magnets projecting downward into the grain to
within a short distance of the bottom. As the grain mixed with iron particles
passes the magnets the iron is caught, and can be released from time to time from
the magnets by raising the lid and brushing it off outside the spout.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Pieter Van Gelder in the Great Seal Patent Office on the
15th September 1881.
"
IMPROVEMENTS
PIETER VAN GELDER, of Liverpool, in the County of Lancaster.
IN AND RELATING TO THE DRIVING OF ROLLERS OF ROLLER-MILLS FOR CRUSHING
OR GRINDING, AND IN APPARATUS FOR PROTECTING THE SAID ROLLERS FROM
THE ACCIDENTAL INTRODUCTION OF IRON PARTICLES BETWEEN THEM." "
In driving roller mills for grain crushing it is usual to drive the two rollers at
different speeds by means of spur gearing, and as this causes great friction the
rollers soon wear. If therefore the teeth are correctly geared to the pitch line,
in a short time (in taking up the wear) they become closer and useless. They are
therefore geared at start so as not to interlock to a true pitch line. The result is
knocking and a fearful noise, and further a tendency is induced in the rollers to
wear unequally and into flats.
Now my Invention consists in running all the rollers by chain gearing, the
roller shaft carrying wheels or discs with projections to fit the chain and hold into
its links, these wheels being much within the rolling circles of the rollers so as not
to come in contact even after much wear of rollers. If there are four rollers, say,
the chain passes over one wheel, under its companion, over the next, under the
next, then round a guide or driving wheel, or both, back to the start. The guide
wheel can be made adjustable to take up slack. In the mills with three rollers
the chain goes over a wheel on the top roller shaft round to the other side of the
wheel on the middle or driving roller shaft, then round the opposite side of the
wheel driving the bottom roller, and so back to the wheel of the top roller, the guide
wheel being dispensed with. This apparatus is applicable for both mills with equal
and mills with differential speed.
The second part of my Invention consists in a simple apparatus for protecting
the rollers from the intrusion of iron particles, and consists in placing in the upper
side of the spout leading into the mill a door that will lift up by hinge or otherwise,
and in this door I fix a series of magnets projecting downward into the grain to
within a short distance of the bottom. As the grain mixed with iron particles
passes the magnets the iron is caught, and can be released from time to time from
the magnets by raising the lid and brushing it off outside the spout.
In the Drawings annexed, Fig. 1 shows a diagram of a four roller mill; Fig. 2,
a three high roller mill; Fig. 3, a link of the kind of chain I usually employ ;
Fig. 4, view of magnet arrangement. In these A, A, aro the rollers; B, C, D, E, various
gear wheels on the rollers; F, compensating wheel on a movable slide to take up
alack of chain; G, chain which goes round toothed wheels in the manner well
known.
The wheels B, C, D, E, are of varying diameter, and in practice, as I prefer to
use the kind of chain, a link of which is shown in Fig. 3, I make them all of
different diameters, but B and E have an equal number of teeth, say, twelve, and
C and D are also equal to each other in this respect, and have, say, ten teeth each,
but on designing the wheels care must he taken to give the teeth of the wheels on
which the back of the chain runs a larger pitch than the other to allow for the
projecting backs of the chain.
In Fig. 4, H is the trough; I, the lid; and J, the magnets; K, the hinge undoing
the lid of the trough..
Having now described my Invention, and the best mode known to me of
carrying it into effect, I wish it to be understood that while I do not bind
myself to the exact details shown, on the other hand make a claim for chain

page_text: gearing in general, and used for. other purposes, as chain gearing has been applied
to cranes, carriages, elevators, and the like, nor the use of magnets broadly for
cleaning wheat from iron particles, but that what I claim under the first head of
my Invention is,―
The driving of rolls of roller mills for crushing or grinding (which rolls are i
liable to wear and consequent reduction of diameter) by chain gearing, substantially
as described.
And under the second head,-
The combination with roller mills driven as above described, of the apparatus
herein described for separating iron particles from granulating materials passing 1
down spouts or other passages to the rolling mills formed of a series of magnets
projecting from a lid opening into such spout or passage in such manner that the
lid can be opened at pleasure and the magnets thrown back with it and then
cleaned of their adhering iron and let down into the spout again, substantially as
described.
In witness whereof, I, the said Pieter Van Gelder, have hereunto set my hand
and seal, this Fourteenth day of September, in the year of our Lord One
thousand eight hundred and eighty one.
PIETER VAN GELDER. (L.S.)