IMPROVE- MENTS IN AND CONNECTED WITH GRINDING OR PULVERIZING APPARATUS.
Year: 1881

page_text: LETTERS PATENT to Philip Middleton Justice, of 14, Southampton Buildings,
in the County of Middlesex, Patent Agent, for an Invention of "IMPROVE-
MENTS IN AND CONNECTED WITH GRINDING OR PULVERIZING APPARATUS.".
A communication from abroad by Joseph Ellicott Holmes, of the City of
Washington, District of Columbia, United States of America.
PROVISIONAL SPECIFICATION left by the said Philip Middleton Justice
nt the Office of the Commissioners of Patents on the 9th June 1881.
PHILIP MIDDLETON JUSTICE, of 14, Southampton Buildings, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN AND CONNECTED WITH GRINDING
OR PULVERIZING APPARATUS.” A communication from abroad by Joseph Ellicott
Holmes, of the City of Washington, District of Columbia, United States of
America.
My Invention relates to that class of grinding mills in which motion is given
to stones or grinding discs running either in the same or in opposite directions,
and also particularly to forming the said discs, or what represents the grinding
stones, with hard and soft plates of metal or other suitable substances alternated,
so that in the wearing away of the softer plates or substances the harder ones will
be left with sharp cutting edges, and also to the placing of the rotating shafts to
which the stones or discs of such mills are attached out of line or eccentrically
placed to each other.
I obtain these ends when using the discs or stones secured to vertical shafts by
making a strong shell, in which the plates of hard and soft materials may be firmly
secured on their edges by suitable bolts and attachments until the entire shell or
disc is properly fitted with the same. The rotating shafts being placed eccentrically
to each other permit the even wearing of the whole surface of the disc, which
otherwise would be worn in grooves or unevenly. The materials to be ground by
this description of mill may be fed by making the upper rotating shaft of a tube
which can deliver substances on a central portion of the lower disc, which is made
with a coarser arrangement of the cutting plates so as to more perfectly crush or

page_text: grind the materials, and thus allow a more even distribution of material over the
entire grinding surface.
In mills where the shaft is run horizontally I place the hard and soft plates or
substances alternated, as before stated, around the periphery of a drum which is
rotated by being secured to the driving shaft, which in this description of mill is
central. Partially surrounding the drum is a section of a hollow cylinder frame
pivoted on an adjusting screw at its upper edge, and also fitted with alternated
hard and soft plates or substances of the same description as the drum. The
weight of this section of a hollow cylinder will naturally cause it to lie against the
drum as it follows the same general outlines, and it is so formed as also to be
adjusted by a screw at its bottom portion, by means of which the substances or
materials to be ground between the inner and outer shells may be delivered either
in a coarse or fine condition as desired. To secure the uniformity of wear in the
surfaces of the drum and concave grinding shell partially surrounding the samo,
an end motion is given to the drum by which it is laterally propelled. In ordinary
buhr millstones much expense is entailed in the constant dressing of the stones
themselves, whilst the first cost is also very considerable.
According to this Invention the materials used are inexpensive, as plates of glass
may be alternated with softer materials for grinding many substances, or shells of
hard steel or case hardened iron are equally applicable, whilst no necessity
whatever arises for dressing the grinding faces, which are always kept sharp by
their own action or the slow wear of the harder substances. Thus great expense
is saved, and no time is lost in the stopping of the mill for the usual dressing of the
grinding faces.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Philip Middleton Justice in the Great Seal Patent Office on the
8th December 1881.
PHILIP MIDDLETON JUSTICE, of 14, Southampton Buildings, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN AND CONNECTED WITH GRINDING
OR PULVERIZING APPARATUS." A communication from abroad by Joseph Ellicott
Holmes, of the City of Washington, District of Columbia, United States of
America.
My Invention relates to that class of grinding mills in which motion is given to
stones or grinding discs running either in the same or in opposite directions, and
also particularly to forming the said discs, or what represents the grinding stones,
with hard and soft plates of metal or other suitable substances alternated, so that
in the wearing away of the softer plates or substances the harder ones will be left
with sharp cutting edges, and also to the placing of the rotating shafts to which
the stones or discs of such mills are attached out of line or eccentrically placed to
each other. To clearly explain how my Invention may be practically employed,
reference is made to the accompanying Drawings, in which Fig. 1 represents a
vertical section of a mill; Fig. 2 represents a side view; Fig. 3 represents a plan
of one of the discs showing the grinding surface; Fig. 4 represents an end
elevation of a mill in which the grinding disc cylinders are placed vertically;
Fig. 5 is a side elevation of Fig. 4; and Figs. 6 and 7 represent enlarged detail
views of parts shown in Figs. 4 and 5. When using the discs or stones secured
to vertical shafts I make a strong shell in which the plates B, B, Fig. 1, of hard
and soft materials may be firmly secured on their edges by suitable bolts and
attachments until the entire shell or disc A is properly fitted with the same, the
rotating shafts R, R, being placed eccentrically to each other, as shown, to permit
the even wearing of the whole surface of the disc, which otherwise would be worn
in grooves or unevenly. The materials to be ground by this description of mill
may be fed by making the upper rotating shaft R of a tube which can deliver
substances on a central portion of the lower disc, which is made with a coarser
arrangement of the cutting plates, so as to more perfectly crush or grind the
materials, and thus allow a more even distribution of material over the entire
grinding surface. In this form of mill C, C, represent spaces for filling in a
skeleton frame; D, D, represent the framework of the mill, and E, E, cross beams
for holding the shafts R, R, which are firmly secured to discs A, A, by means of
hubs O, O; F is the bearing beam adapted to raise and lower the discs by means
of screw bolts m, m, and lugs n, n. While the shafts R, R, are eccentric to each
other the faces of the discs are parallel, the object being to insure perfectly true
surfaces without the necessity for dressing. Pulleys P, P, are used to impart
motion to the shafts R, R. In the centre of the disc I form a division of about
to of the entire diameter of the disc; this I do by means of a ring cast with the
skeleton frame as at W, Fig. 3, and I place wedge shaped chilled cast plates on
end alternated with pieces of wood of the same shape, and thus form a crusher for
reducing all coarse substances before they pass between the discs. In constructing
mills of this class I use plates of wrought iron, 4 to 6 inches wide, and to
thick, and of such lengths as will fill about one half the whole space in the discs.
The plates should be case hardened on the surface, the edges they present are
consequently sharp, and when the discs are eccentrically placed the blades or
plates will keep sharp and true until entirely worn out. I use soft iron, wood,
veneer, hard rolled paper, or suitable substances for the alternate plates. In mills
where the shaft is run horizontally, as shown in Figs. 4 and 5, I place the hard

page_text: and soft plates or substances F, F, alternated, as before stated, around the periphery
of a drum B which is rotated by being secured to the driving shaft D, which in
this description of mill is central. The grinding plates are held in position by
wedge shaped divisions or abutments secured to the cylinder, and the fixed grinding
surface is prepared in the same manner and filled in on the concave surface H, H,
for a distance equal to about one third of the circumference of the cylinder; Fig. 7
shows how the plates E may be held in position against the action of centrifugal
force by the ring F, which is bolted to the end of the cylinder while the wedge
shaped abutments G, G, Fig. 6, hold the plates parallel and firm. The abutments
are cast in chill moulds, and the bolts may be cast as parts thereof, by means of
which the abutments may be secured to the surface of the cylinder. The concave
or fixed grinding surface H, H, is held in place by the screws L, K, and is hinged
on a pivot near its upper portion (not shown) in order that it may be brought in
or removed from close contact with the revolving cylinder, and by this means the
substances ground may be delivered either in a coarse or fine condition as desired.
When grinding very hard substances I substituto for the motion of the eccentrically
placed discs, shown in Fig. 1, an end motion to the cylinder by means of the worm
wheel on the shaft, the end motion being about one half an inch back and forth
for, say, each twenty or twenty-five revolutions of the cylinder. In ordinary buhr
millstones much expenso is entailed in the constant dressing of the stones themselves
whilst the first cost is also very considerable. According to this Invention the
materials used are inexpensive, as plates of glass may be alternated with softer
materials for grinding many substances, or shells of hard steel or case hardened
iron are equally applicable, whilst no necessity whatever arises for dressing the
grinding faces which are always kept sharp by their own action or the slow wear
of the harder substances. Thus great expense is saved and no time lost in the
stopping of the mill for the usual dressing of the grinding faces.
Having thus described the nature of the Invention of my foreign correspondent,
and how the same may be practically employed, what I claim as new and desire
to secure by Letters Patent is,―
1st. In grinding mills the construction and use of grinding surfaces formed of
alternate plates or layers of hard and soft plates, whether used with or without a
central crusher, all substantially as and for the purposes set forth..
2nd. In grinding mills the application and use of grinding surfaces eccentrically
placed to each other and operated upon separate shafts or axles, all substantially
as and for the purposes set forth.
3rd. In grinding mills the combination with a revolving grinding cylinder,
which may or may not be capable of end motion, of a pivoted adjustable grinding
surface, all substantially as and for the purposes set forth.
In witness whereof, I, the said Philip Middleton Justice, have hereunto
set my hand and seal, this Eighth day of December, in the year of our
Lord One thousand eight hundred and eighty one.
Signed, sealed, and delivered
in the presence of
HENRY B. HATCHWELL,
W.C.
14, Southampton Bldgs.,
PHILIP M. JUSTICE. (L.S.)