Improvements in Apparatus for Crushing or Reducing Ores.
Year: 1890

page_text: Date of Application, 16th Dec., 1890-Accepted, 7th Feb., 1891
COMPLETE SPECIFICATION.
Improvements in Apparatus for Crushing or Reducing Ores.
DANIEL BRENNAN Junior, of Bayonne in the County of Hudson and. State
of New Jersey United States of America, Inventor 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 :-
In the reduction of ores by the gradual reduction process as now generally
practised, much waste of time and power is caused by simultaneously passing
material of greatly varying sizes through the reducing rolls; and the object of my
invention is to effect a more economical and expeditious reduction of the ores by
assorting the material, after the initial breaking of the same, with special reference
to the adjustment and capacity of the several reducing rolls in the apparatus or
system, and feeding the material thus graded to the respective reduction rolls.
The invention consists in the method and means as hereinafter particularly
described and defined in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
all the figures.
Figure is a longitudinal sectional elevation of an ore-reduction apparatus
embodying my invention, the view being taken on the broken line 1, in
Figure 2:
Figure 2 is a vertical sectional elevation, the view being taken on the broken
line 2-2, in Figure 1; and
Figure 3 is a similar view on line 3-3 of Figure 1.
In the building A, of suitable construction is arranged the machinery for carrying
out my invention.
The material to be treated is received in the building A, after its preliminary or
initial crushing, and containing little or no finished product, from a carrier belt,
indicated by dotted lines at a, in Figure 1, or from any conveniently located
crusher, hopper or other source of supply.
In the construction illustrated, the carrier belt a, passes around a pulley a¹, on
the short shaft a, delivering the material to a hopper B, to which a chute b, is
complementary, the same chute leading to a pair of crushing rolls C..
The rolls C, as also the other sets of rolls hereinafter to be mentioned, are pre-
ferably of the adjustable variety, and of the special construction illustrated and
described in another application for Letters Patent of even date herewith
No. 2053190.
The product from the crushing rolls C, is received on a carrier bell or conveyor D,
which delivers to the boot e, of an elevator E, the said elevator depositing the
material into a chute E', arranged at the upper end of the elevator, which chute E¹
delivers the material to the finishing screen F, of the apparatus. The finishing
screen, is preferably of the rotary form, and its mesh is of a degree of fineness
to permit only the finished product to escape therethrough.
From the finishing screen F, the tailings pass, either directly, as shown, or
indirectly, to a separator and feed G, that supplies the material to a series of
reduction rolls C1, C2, C3. The feed G, consists of a series of graduated screen
sections G¹, G, G, that act to assort the tailings, feeding the same to the series of
reduction rolls C¹, C2, C3, the material being guided to the rolls from said graduated
feed screens by slides or hoppers B1, B2, B3, and chutes, 2, 63, complementary to
said hoppers, sliding gates or doors 4, being arranged to control the entrance

page_text: to said chutes and regulate the flow of material fed to the rolls by the feed
screens G, G, G³.
Each set of reduction rolls C, C³, C³, is adjusted with special reference to the
grade of material delivered thereto by that particular section G1, G2, G³, of the
feed G that supplies the same.
Any material too coarse to escape through the last section G³ of the feed, passes
out from the end y, thereof, and is delivered through the hopper B, and chute, to
the first set of crushing rolls C, to be reground with the incoming new material,
With the graduated screen sections ( G. G, forming the feed for the various
sets of rolls, as above described, only such material will be fed to each set of rolls,
as is best suited to the capacity and adjustment of said rolls, whereby the power of
the rolls will be utilized to the maximum extent and the loss of power coincident to
the operation of rolls under present methods obviated.
With material of a comparatively uniform size and rolls adjusted to correspond
thereto, as above described, it is evident that the rolls will act directly and
effectively to crush the material, whereas with material of greatly varying sizes
the rolls must be adjusted with reference to the larger fragments, with the result
that much of the material passes through the rolls uncrushed or practically so,.
power being uselessly expended thereby. Power, is further uselessly expended by
the rolls exerting more or less force in compacting the material preliminary to the
actual crushing action, as the material of mixed grades will be forced apart in
proportion to the size of the larger fragments, so that it becomes necessary to feed
heavily and depend mainly on the accidental crushing of the fragments by pressure
among themselves, which indirect crushing is not as satisfactory or economical
as could be desired. Further, the ungraded material is liable to offer uneven
--resistance at different points of the rolls, causing uneven wear and uneven action
of the rolls.
The product of the reduction rolls C, C2, C3, is also received by the belt D, and
conveyed together with the imaterial from the roll C. by said belt and the
elevator E to the finishing screen F, the unfinished fragments or tailings-being-
again received by the graduated feed G, and by it again graded and fed to the
respective rolls.
The finishing screen F and the feed screens, are preferably arranged in a
continuous series and supported on a common inclined shaft g', that is journaled in
any suitable bearings, supporting rollers, being also provided at one or more
points along the screens.
The main features of the apparatus, the rolls, conveyors, feed, &c., are actuated,
in the arrangement shown, as follows:-
The main drive shaft H, extends longitudinally in the building A, and is
provided with a drive pulley h, that is driven from any convenient power, and with
pulleys, in position to receive belts I, that actuate the drive pulleys of the
several sets of rolls C, C, C, C³
f:
A. belt, also driven from the shaft H, extends upward to a pulley k, on a short
shaft K, on which shaft K is a pinion, that meshes with a gear wheel g³, on the
shaft of the screens.
On the shaft also is a second pulley, from which extends a belt L', to a
pulley, on a short shaft L; the shaft L is geared to the short shaft a³ on which is
a drive pulley m, from which extends downward a belt M, to a pulley d; on a short
shaft D. The pulley or roller d', on shaft D', actuates and supports at one end
the carrier belt D, which as previously explained conveys the material from the
crushing rolls C and reduction rolls C', C³, C, to the boot e of elevator E, the
opposite end of the belt D being similarly supported by a pulley d³.
From a pulley H', on main drive shaft H, extends upwardly a drive belt N, to a
drive pulley N', on a short shaft N, on which is also fitted the pulley or chain
wheel E, that drives the elevator E.
With an apparatus constructed as above described, the material is treated as
follows: It is first received from the conveyor belt a, in the hopper or slide B,

page_text: passing thence, by chute b, to the set of crushing rolls C, the product of said rolls
being received by the belt D, and conveyed to the elevator E, by which it is
carried to the finishing screen F. Any finished product will escape through the
meshes of the finishing screen F to the hopper F¹, or to any chute, conveyor, or
desired place of deposit.
The tailings from the finishing screen F pass to the feed G, of the varying
reduction rolls C1, C2, C3, the finer products being fed by the screen section (³, of
feed G, to the corresponding rolls C, the slightly larger fragments by the
section G of the feed to the rolls C, and so on, it being understood of course that
the number of sets of reducing rolls and their corresponding sections of the feed
screen, may be multiplied to any desired practical extent in accordance with the
required degree of fineness of the product and the power of the several machines.
The product of the reduction rolls C1, C2, C3, is received by the belt D, and
conveyed with the material from the rolls C, to the elevator E, to be again passed
to the finishing screen F, and the tailings again received by the feed G, and by it
assorted and fed to the several sets of reducing rolls.
With the above described apparatus, the finishing screen being common to all
the rolls, a considerable amount of coarse material will be always present with the
finished product on the way to the finishing screen and in the latter, and will act to
agitate the finished product and materially facilitate its exit through the meshes of
the said screen.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is-
1. A reducing apparatus constructed and operating substantially as shown and
described.
2. An apparatus for reducing ores, comprising crushing apparatus and grading
screens arranged in connection therewith, for grading and regrading the material
until the same is fully reduced by the crushing apparatus, substantially as shown
and described.
3. The combination, in reducing apparatus for ores, of a series of crushers or
reducing rolls, a series of separator screens common to all of said rolls, and
conveying mechanism between the rolls and their said common separator screens,
the separator screens forming the receiver for the coarse products or tailings of
each of said rolls and forming a distributor for the delivery of said tailings again to
the several rolls, substantially as described.
4. The combination, with a series of reducing rolls, of a finishing screen, a series
of separator screens, and conveying mechanism, substantially as described, the
separator screens forming a receiver of the tailings from the finishing screen, and
forming a distributor of the said tailings again to the rolls to which it is common,
as set forth.
5. In an apparatus for reducing ores, the combination, with a series of reducing
rolls or crushers, of a series of separator screens for feeding graded material to the
respective rolls, a finishing screen, and conveying mechanism, substantially as
described, said finishing screen and conveying mechanism forming a conductor for
the material from the several rolls to the common separator screens, and the
finishing screen affording the only exit of the finished product from the apparatus,
whereby the tailings resulting from all the rolls will be returned to the separator
screens and be again distributed to the rolls, substantially as described.
6. In an apparatus for reducing ores, the combination, with a series of reducing
rolls, a finishing screen, affording the only exit from the apparatus of the finished
product of the rolls, a series of separator screens, forming a receiver for the tailings
from the said finishing screen, and forming a distributor for distributing said tailings
to the rolls, and a conveying mechanism, substantially as described, common to all
the rolls of the apparatus, the whole forming a continuous circuit for the unfinished
material, substantially as described.

page_text: 7. In an apparatus for reducing ores, a series of reducing rolls, and a finishing
screen common to all the said rolls, for receiving both the finished and unfinished
product thereof, in combination with a series of separator screens for receiving the
tailings of the common finishing screen, and forming a distributor of the graded
tailings to the reducing rolls, and conveying mechanism, substantially as described,
completing the circuit from the rolls to the screens, substantially as described.
8. In an apparatus for reducing ores, a series of reducing rolls, and a series of
separator screens common to all the rolls, and to which the unfinished product of all
the rolls in the circuit is delivered, said separator screens forming a feed for feeding
graded material to all of said rolls, in combination with a finishing screen, and a
conveying mechanism, completing the circuit between the rolls and the separator
screens, substantially as described.
Dated this 16th day of December 1800
D. BRENNAN, Jr.
By A. M. & Wm. Clark,
53, Chancery Lane, London, W.C., Patent Agents.