Improvements in and relating to Grinding Mills.
Year: 1895

page_text: Date of Application, 7th Oct., 1895
1000
2008
PROVISIONAL SPECIFICATION.
Improvements in and relating to Grinding Mills.
I, JAMES STIRRAT COCHRAN of 29 Nowstead Road Liverpool in the County of
Lancaster, Engineer do hereby declare the nature of this invention to be as follows:-
My invention relates to certain improvements in the construction of grinding mills
of the disc type in which two opposing discs are caused to revolve in opposite
directions the material operated upon being admitted through a central opening in one
of the said discs and being ground by the perenssive and cutting action of ribs or other
projections formed upon the faces of the said discs
My said invention relates to (A) an improved form and method of construction of
the grinding faces of the said discs and (B) to improved mechanisin for varying the
space between the said dises
In my improved construction of grinding disc I form the working face of four or
more segments of hard cast steel or other metal having a number of radial bs and
two or more annular projecting rings crossing the said ribs, formed thereon. Theso
said segments are first fitted to the foundation disc-which has previously been turned
and accurately balanced-to then ground up truly in place, upon then faces &
edges, are then removed and all made of similar weight by pouring a small quantity
of molten lead or other metal into a dovetailed cavity formed in the backs thereof for
the purpose. Tho segments are afterwards replaced upon the main disc and a perfect
balance is thus ensured
The object of this method of construction is to euable the renewal of the grinding
faces from time to time and to obviate the necessity of re-balancing the dises after
each renewal, the segments all being of the same weight ensures a perfect balanco
being maintained
My improved mechanism for adjusting the space between the ginding faces is as
follows
1
The spindle carrying the adjustable disc is extended outwards beyond the second
bearing, is turned down to a smaller diameter and passes through a boss formed
upon a hand wheel, this said boss 18 screwed upon the outside and is carried by a yoke
attached by studs to the end bearing bracket.
By turning the hand wheel the movable disc is diawn away from or pushed towards
the non-movable disc The said hand wheel has a number of notches in its periphery
which engage a spring to hold it in any position it may be required
Dated this 5th day of October 1895.
Improvements in and relating to Grinding Mills.
I, JAMES STIRRAT COCHRAN of 29 Newstead Road, Liverpool in the County of
Lancaster, 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 certain improvements in the construction of grinding mills
of the "disc" type in which two opposing discs are caused to revolvo in opposite
directions, the material operated upon being admitted through a central opening in

page_text: one of the said discs and being ground by the percussive and cutting action of ribs or
other projections formed upon the faces of the said discs
My said invention relates to (A) an improved form and -method of construction of
the grinding discs and (B) to improved mechanism for varying the space between the
said discs
My said improved construction of grinding disc consists in forming the working
faces of same of hard cast steel or other suitable material-in four or more segments---
having upon their outer surfaces a number of radial ribs and two or more concentric
projecting rings crossing said ribs
These said sogments, after being fitted and bolted upon the foundation discs aro
ground up truly, in situ, upon their faces and edges, are then taken off and the lighter
plates of each set are brought to a weight equal to the heaviest by pouring a small
quantity of molten lead or other motal into cavities formed in the backs thereof for the
purpose. The segments are then replaced upon the discs and a perfect balance is thus
ensured.
The object of this method of construction is to enable the renewal of the grinding
faces from time to time and to obviate the necessity for re-balancing the discs after
each renewal.
Fig 1 upon the sheet of drawings hereunto appended is a sectional elevation of a
pair of discs constructed according to my said invention in which A and B are the
foundation discs which are turned all over and accurately balanced in the usual
manner by drilling shallow recesses in the backs thereof on the heavy sides.
C. C C C are the hard metal facing plates, Fig. 2 being a front view of samo.
The material to be ground is fed through the oponing X and is first caught and
broken by the ribs 1 and after passing ring 2 is caught by ribs 3 and ground
sufficiently fine to allow of its passing ring 4. Ribs 5 complote the grinding and the
material then passes out between 1ngs 6. The grinding of the material is thus
effected in three stages and the rings 2 and 4 provent the material passing from the
first to the second and from the second to the third stage until it shall have been
reduced sufficiently fine to pass saine and likewise the distance apart of the
determine the ultimate degree of fineness of the ground material
rings
The spindle carrying disc A has collars upon it abutting on the bearings, which
maintain it in a fixed position and the adjustment of the space between the discs is
effected by moving the disc B by means of the mechanism represented by Figs 3, 4, and 5,
consisting of a hand-wheel D having an elongated screwed boss E fitting into the
yoke which is attached to the end bearing bracket by studs G. The end of the
spindle His turned down and passes through the hand wheel and is secured therein
by the locknuts I By turning the hand-wheel in one or the other direction the
disc B is moved towards or away from disc A. The hand-wheel has a number
of notches formed in its periphery which engage a spring S and hold it in any position
required.
Having now particularly described and ascertained the nature of my suid inven-
tion and in what manner the same is to be performed, I declare that what I
claim 18
-
1. In grinding mills of the class described, the formation of the grinding or working
faces of the opposing discs of four or more segments of hard cast steel or equivalent
material, having radial ribs and concentric projecting rings formed thereon, substantially
as herein described and illustrated and for the purpose stated.
2. In grinding mills of the class described, the mechanism for effecting the
adjustment of the movable disc consisting of the hand-wheel D with screwed boss E,
yoke F and spring S substantially as herein described and illustrated
Dated the 2nd day of July 1806
JAMES STIRRAT COCHRAN,
Por G. F. Thompson.