IMPROVE- MENTS IN CRUSHING AND GRINDING MILLS
Year: 1881

page_text: LETTERS PATENT to William Newzam Nicholson and William Mather, both of
Newark-upon-Trent, Agricultural Engineers, for an Invention of "IMPROVE-
MENTS IN CRUSHING AND GRINDING MILLS."
PROVISIONAL SPECIFICATION left by the said William Newzam Nicholson
and William Mather at the Office of the Commissioners of Patents on the
4th July 1881.
WILLIAM NEWZAM NICHOLSON and WILLIAM MATHER, both of Newark upon
Trent, Agricultural Engineers. "IMPROVEMENTS IN CRUSHING AND GRINDING
MILLS."
Our improvements consist in mounting in a fame one or more pairs of rollers
furnished with suitable teeth, and revolving either at the same or at different
speeds in contrary directions. Either one or both of the lower pair of rollers or of
the top pair, where only one pair is used, is provided with an adjustable concave
which embraces a portion of the lower periphery of its respective roller and is
furnished with teeth corresponding to it. The concave or concaves pivot at a
central point below the rollers, each being provided with separate adjusting levers
with weights or springs for regulating the distance between it and its roller, and
allowing any foreign or hard substance to pass between them without causing
damage to the inill. The partially crushed or ground substance falling from
between the toothed rollers can be directed by adjustable guides between either
one or both sets of concaves and rollers, and there undergoes a further crushing or
grinding, so reducing it to any required degree of fineness.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Newzam Nicholson and William Mather in the Great Seal
Patent Office on the 2nd January 1882.
"
WILLIAM NEWZAM NICHOLSON and WILLIAM MATHER, both of Newark-upon-
Trent, in the County of Nottingham, Agricultural Engineers. "IMPROVEMENTS IN
CRUSHING AND GRINDING MILLS."
Figure 1 represents in section our improvements applied to a crushing and
grinding mill having one pair of toothed rollers A and A' which are mounted in
the frame F and are geared together so as to revolve at the same speed or at
different speeds The substance to be crushed or ground enters between the
toothed rollers A and A¹ from the top in the direction of the arrow, and is there
partially crushed or ground. It then passes between the rollers and their respective
concaves B and B¹, where the substance is further reduced and then discharged at
the sides of the mill, as shown by the direction of the arrows. The two concaves B
and B' which are of the same width as the rollers have teeth which correspond to
those in their respective rollers, and are pivotted at a central point C to the mill
frame F. A guide c is also pivotted at C which can be adjusted so as to allow the
substance to pass between either one or both of the concaves and their respective
rollers. The concaves B and B¹ are held up to the rollers by the levers and
weights and b¹, or springs may be used in place of weights, as shown in Figure 2,
so that any foreign or hard substance can pass between the rollers and their
concaves without risk of damage to the mill. Figure 2 shows our improvements
applied to a mill having two pairs of rollers, A and A¹ being the upper pair, and
B and B¹ the lower pair. Mounted in the frame F between these two pairs of
rollers is an adjustable guide a by which the partially crushed or ground substance
falling from between the upper pair of rollers can be directed between the lower
pair, as shown, or by moving the guide a to the position shown in dotted lines the
partially crushed or ground substance is diverted to the outside of the mill without
passing through the lower pair of rollers. The arrangement of the rollers B and B
and their concaves C and C is substantially the same as that shown and described
in Figure 1, except that the levers have springs c and c¹ instead of weights for the
purpose before described.
We do not confine ourselves to the use of concaves to
both of the rollers, as shown in Figures 1 and 2, as for some purposes it is sufficient
to have but one concave to one of the rollers. Figure 3 shows in section our
improvements applied to a mill having an upper pair of rollers A and A¹ and one
lower roller B. Between these there is an adjustable guide "," as described in
Figure 2, so that the partially ground substance may be either discharged at the
side of the mill or be passed between the roller B and its concave C and be further
crushed or ground. The concave C is pivotted at a point "d" and is provided with
a lever and weight c or with a spring, as before described.
Having now described our Invention, and in what manner the same it is to be
carried into effect, what we claim is,-
1st. The use and application of concaves to either one or both of a pair of rollers
in crushing or grinding mills, so arranged that the material to be crushed or
ground after passing between the rollers can be passed between the rollers and
their concaves and there further reduced, substantially as described and shown in
Figures 1 and 2.
2nd. The combination of the upper pair of rollers and the lower pair of rollers
and concave or concaves, substantially as described and shown in Figure 2.

page_text: 3rd. The combination of an upper pair of rollers and a single lower roller and
concave, substantially as described and shown in Figure 3.
In witness whereof, I, the said William Newzam Nicholson, on behalf of
myself and the said William Mather, have hereunto set my hand and seal,
this Thirty first day of December, in the year of our Lord One thousand
cight hundred and eighty one.
WILLIAM NEWZAM NICHOLSON. (L.S.)