Improvements in the Scrapers of Edge-runner Grinding Mills.
Year: 1890

page_text: Date of Application, 2nd June, 1890
Complete Specification Left, 2nd Apr., 1891-Accepted, 9th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in the Scrapers of Edge-runner Grinding Mills.
I, PERCY JOHN NEATE, of Rochester in the County of Kent, Consulting and
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:
My invention has for its object improvements in the scrapers to be employed in
edge runner grinding mills and in carrying it into effect in an edge runner mill
of the fixed bed plate type I utilize the spaces between the runners for the action of
certain scrapers for the collection, distribution and disposal of the material to be
ground.
'
Firstly For the collection of material I provide a shelf above and as near as
convenient to the path of the runners, and upon this shelf, I allow a stream of
unground material to fall until the pile thus formed blocks the orifice of the feeding
spout.
Then upon any convenient rotating part of the mill I fix a collecting scraper
which as it revolves strikes the accumulated heap and throws a portion of it along
a perforated plate guiding it under the runners. The perforated portion of the
plate is not above the runner path but outside it, so that only the larger lumps are
thrown under the runners, the remainder-falling-into-a-race-outside the path of the _
runners.
After each rotation of this collector more raw material falls down the feed pipe
until the leap returns to its original size and again blocks the mouth of the feed
pipe. A slide or other suitable adjustment on the nose of this pipe regulates
the size of the heap and therefore the quantity fed to the mill per revolution.
The collecting arm may be raised or lowered instead but the former is the
preferable plan.
By making more than one shelf and feed pipe the apparatus may be used for
mixing various materials in adjustable proportions.
This
Second To properly distribute the material thus fed to the mill I provide
radiating arms rigidly fixed to the centre shaft or its appurtenances. Each radial
arm carries a rigidly fixed sleeve capable however of radial adjustment.
sleeve carries a bar nearly tangential to the runner path and pivotted to it- in
such a manner that its free end can rise considerably but is unable to fall below a
certain point.
The free end carries and is rigidly attached to a frame which in its turn carries a
series of flat bars normal or nearly so to the surface of the runner path and with
their lower ends near the said surface. The lower ends of these bars pass through
the material being ground, and either distribute it over the bed plate or otherwise
deal with it. To compensate for the wear of these bars or blades I make them
adjustable in slots in the frames, each slot containing a bar and a wedge the latter
being driven up tight by a set screw passing through a suitable lug on the casting,
and thus holding the bar fast in the desired position.
I use these bars or blades for four distinct purposes as follows:-
(A) To throw the partly crushed material outwards towards or into a race
outside the runner path. (B) To throw the coarser particles back towards the
centre of the mill (and for this purpose the blades are somewhat lifted above the
bed plate). (C) To sort out the larger lumps thrown into the outer race and
throw them back under the runners, and (D) to collect the finer portions of the
partly ground material lying on the race outside the runner path and to dispose of
the same by throwing it down suitable shoots into the elevators which take it to
the sieves.

page_text: These last mentioned scrapers should be set close to the race so as to pick up
the small particles and powder and they also gather up the small material which
drops through the perforated plate over which the feed is propelled by the
collector.
Dated this 2nd day of June 1890.
PHILLIPS & LEIGH,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Scrapers of Edge-runner Grinding Mills.
1, PERCY JOHN NEATE, of Rochester in the County of Kent, Consulting and
Mechanical 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 improvements in the scrapers of edge-runner grinding-
mills, and relates, more particularly, to grinding mills of the fixed bed-plate type
in which the spaces between the runners are utilized for the presence and action of
the improved scrapers, which are specially adapted, in virtue of their improved
construction, for the collection, distribution, and disposal of the material to be
ground.
In order that my invention and the means by which it is. to be carried into
practical effect may be thoroughly understood, I will now describe them in detail
referring, in so doing, to the accompanying drawings which are to be taken as part
of this Specification and read therewith.
Fig. 1 is a sectional elevation taken on the line A-B of Fig. 2.
Fig. 2 is a plan of the same.
Fig. 3 is a sectional front elevation taken on the line C-D of Fig. 4.
Fig. 4 is a plan of the same.
Figs. 5 and 6 are, respectively, front elevation and plan of the scraper illustrated
in Figs. 3 and 4.
Fig. 7 is a sectional side elevation illustrating the means by which the scraper
blades are held in the scraper head.
Figs. 8, 9 and 10 are details of the knuckles to which the scraper-arms are
pivotted.
Figures 11 and 12 are plan and side view of a scraper-arm.
Referring to Figs. 1 and 2, a is the collecting shelf upon which the stuff to be
ground is fed down a spout 6, the mouth of which is under the control, in respect of
its delivery, of an adjustable throttle plate c. This plate may be replaced by any
other equivalent device. Inasmuch as the spout is inclined to the shelf ilg thic
projection of the heap of stuff past the plate on to the shelf will be in proportion
to the sectional area of the opening exposed by the rise of the plate and there-
fore the quantum of stuff which can be fed to the edge runners each time that
the scraper passes the mouth of the spout is in direct proportion to the sectional
area of the opening, and is easily controlled by the said plate c.
t
d is the collecting scraper.
It is shewn as fixed to and carried by the vertical
shafte of the mill. My invention does not confine me to any special or particular
means for rotating the scraper, and I may attach it to any rotating part of the mill
so long as it will be carried rond in a plane parallel with the shelf a.
The shelf a is perforated and is vertically over a path e outside that of the
edge runners, so that the small stuff falls down through the perforations, while the
lumps are fed down the inclined shoot f on to the runner path.
The adjustment of the feed down the spout may be arranged for by making
the scraper adjustable in respect of its distance above the shelf a, but I prefer
that this adjustment should be effected by the regulation of the plate c, for

page_text: then it can be done while the mill is running, and without it being necessary to
stop it.
It should be borne in mind that the delivery spout may be duplicated for the
purpose of delivering on to the shelf a a feed of materials of variable constituent
proportions.
The second part of my invention relates to improved means for distributing the
stuff after it has been fed to the mill, and is illustrated in Figs. 3 to 12.
7 is a radial or approximately radial arm, preferably of a cross section other
than circular. It is fast upon the central shaft e. There may be as many of these
as necessary, preferably, one in front of each edge-runner.
Each arm is fitted with a distributor constructed as follows is a sleeve capable
of adjustment upon its arm 9 at a greater or less distance from the axis of the
shaft e
The sleeve is after adjustment fixed rigidly to the arm. k is a bar
pivotted to the sleeve j, and, in virtue of its being so pivotted, it can rise to any
extent, but is prevented from dropping beyond a certain operative level by the
presence upon the said sleeve of a projecting plane or shelf in its path.
m is a frame fixed upon, or to, the end of the bar k. n, n are bars of a suitable
section. They are fixed in the frame m at a suitable height and distance apart
for them to distribute the stuff to be ground suitably over the runner-path.
The wear of the bars n is compensated for by making them adjustable in respect
of their projection beneath the underface of the frame m. This is accomplished,
preferably, by the device illustrated, which consists of a wedge and a set
screw p passing through a suitable lug on the frame.
The adjustability of the bars n is not confined to their height above the runner-
path, but extends to their rake, ie, to the angle at which they are set with the
axis of the arm k.
The utilities of the distributors constructed as above described are as follows :-
(a). To throw the partially crushed material outwards or, in other words, into a
race or path outside the runner-path.
(b). To throw the coarser particles back towards the centre of the mill.
The relative heights and rakes of all the bars n will therefore be adjusted
accordingly.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed. I declare that what I
claim is,
1. The combination of perforated annular shelf, inclined delivery spout, and a
regulating plate, as set forth.
2. The combination with any rotating part of the mill of a scraper adapted to
take away from the deposited heap of stuff a regulatable quantity thereof, as set
forth.
3. The combination of bar pivotted on a sleeve rigidly fixed upon a radial or
approximately radial arm, as set forth.
4. The combination of bar, frame, and vertical bars, constituting the distributor,
as and for the purpose set forth.
5. The combination with the frame of the distributor, of a series of adjustable
vertical bars, as set forth.
Dated this 2nd day of April 1891.
PHILLIPS & LEIGH.
22, Southampton Buildings, Chancery Lane, W.C., Agents for the Applicant.