Improvements in Mills for Grinding Ores, Cements, Colours, and other Substances.
Year: 1895

page_text: Date of Application, 28th Nov., 1895
Complete Specification Left, 28th Sept., 1896-Accepted, 31st Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in Mills for Grinding Ores, Cements, Colours, and
other Substances.
I, WILLIAM HENRY COWARD, of Hastings Villa, Bexley Road, Erith, in the,
County of Kent, Engineer, do hereby declare the nature of this invention to be as.
follows:-
My invention relates to an improvement in mills for grinding ores, cements,.
colours, and other substances, of that kind for which previous Letters Patent were
granted to me dated April 20th 1891, No. 6795; and it has for object to render
the grinding action much more efficient by increasing the area of grinding surface
which is in operation at one time.
The improved machine consists essentially of a cylinder rotating on a horizontal
axis and provided with two or more sets of internal pockets or cups for raising the
material and returning it to the grinding surfaces, one or more stationary shoes or
grinding blocks within the cylinder each fixed to a shaft anchored outside the
cylinder to a swivel bearing, the shaft and block being held stationary by an arm
and pressed upon by a spring or weight, and of a number of grinding balls or
rollers interposed between the shoe or block and the grinding surface of the
cylinder so that the grinding action will take place both between the balls and the
cylinder and between the balls and the shoe or block. These balls or rollers which
may be made of metal or of emery or other abradent composition or material, are
partly received in corresponding sockets in the shoe and partly run in grooves of
corresponding section formed in the grinding surface of the cylinder, and they are
caused to revolve more or less in their sockets by the frictional contact of the
cylinder through the medium of the material undergoing the grinding action. The
socketted face of the shoe corresponds in curvature and extent to about one third
the circumference of the cylinder and the position in which it is held is towards
the ascending side of the cylinder so that the upper side of the shoe forms an
inclined shoot by which the particles raised by the cups and showered down upon
it are returned to the point of entry between the grinding surfaces. The sockets
in the shoe are so shaped that such of the material as may adhere to the grinding
balls or rollers after passing under them, will be carried between the balls or rollers
and their sockets in the shoe and again subjected to the grinding action between
those surfaces before being raised by the cups and returned to the point of entry
between the balls or rollers and the cylinder.
The grooved grinding surface of the cylinder is constructed in sections secured
in a dove-tailed seat and the outlet mouth of the cylinder would be of large
diameter and connected with an exhaust fan by a cone so that any particles falling
out of the air current will be returned to the mill.
Dated this 28th day of November 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.

page_text: Improvements in Mills for Grinding Ores, Cements, Colours, and
other Substances.
I, WILLIAM HENRY COWARD of Hastings Villa, Bexley Road, Erith, in the
County of Kent, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to an improved mill for grinding ores, cements, colours, and
other substances, the mill being of that kind for which previous Letters Patent
were granted to me dated April 20th 1891, No. 6795; and the invention has for
object to render the grinding action much more efficient by increasing the area of
grinding surface which
in operation at one time.
The improved mill is sufficiently illustrated in the accompanying drawing which
represents a partial section of the grinding shoe and as much of the cylinder as is
necessary to explain the improvements. It comprises a cylinder A similar to that
described in my former patent rotating on a horizontal axis and provided at the
sides with sets of internal pockets or cups (not shewn) for raising the material and
returning it to the grinding surfaces. Within the cylinder A is a stationary shoe B
in the form of a segment of a cylinder fixed to a cantilever C anchored outside the
cylinder in a couple of plummer blocks so as to hold the block stationary. D are
grinding blocks (one only being shown) fitted to slide in radial guides E in the
block B, the blocks D having hemispherical cavities in which are received grinding
balls F which run in a semi-circular groove a in the periphery which forms the
grinding surface of the cylinder so that the grinding action will take place both
between the balls F and the cylinder A and between the balls and the grinding
blocks D as the balls revolve in their sockets by the frictional contact of the
cylinder. The cylinder revolves in the direction of the arrow and the shoe B
which corresponds in curvature and extent to about one third the circumference of
the cylinder A is held in the position shewn towards the ascending side of the
cylinder so that the upper side 6 of the shoe is inclined and forms a shoot with
raised flanges by which the particles raised by the cups and showered down upon
are returned to the point of entry between the grinding surfaces. The grinding
blocks D are free to move radially in the shoe B and are pressed upon by springs G
to maintain the necessary pressure between the grinding surfaces, and the sockets in
these blocks are a loose fit towards the leading side whilst at the opposite side the
blocks project slightly into the groove a of the cylinder so as to prevent the balls
jumping out of the sockets. There may be two series of grinding blocks D and
balls F fitted side by side in the same shoe B, the balls running in separate
grooves a side by side in the periphery of the cylinder. The grooved grinding
surface of the cylinder may be constructed in sections secured in a dovetailed seat
in the circumference of the cylinder and the material may be fed to the cylinder by
a screw conveyor and the outlet mouth of the cylinder may be connected with the
exhaust fan by a cone so that any particles falling out of the air current will be
returned to the mill all as described in the Specification of another application for
Letters Patent dated the 30th day of November 1895, No. 22982.
it
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The herein described improvement in grinding mills consisting in the combination,
with a revolving cylinder and a segment-shaped shoe held in position therein as

page_text: described, of grinding balls running in the circumferentially-grooved periphery of
the cylinder and revolving in sockets in spring-pressed grinding blocks fitted in the
shoe substantially as specified.
Dated this 28th day of September 1896.
A. M. & W M. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.