Improvements in Ore Roasting Furnaces.
Year: 1894

page_text: Date of Application, 8th May, 1894-Accepted, 15th Dec., 1894
COMPLETE
SPECIFICATION.
Improvements in Ore Roasting Furnaces.
I, HORACE FOWLER BROWN of 800 Monroe Street, Chicago, Illinois, United
States of America, Mechanical and Mining 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 various improvements in reverberatory ore-roasting
furnaces, especially applicable to curved furnaces, as furnaces of annular or horse-
shoe shape; and in my present application all of my improvements are shown in
connection with a furnace of this character, though some of the features will be
found desirable with furnaces of other forms. Generally stated my furnace, as
illustrated, operates in the following manner :-
An ore-roasting chamber, in the form of an arc of a circle, with an open space
completing the circle, is provided at intervals with reinforcing furnaces which
communicate by way of the ore-roasting chamber with a chimney. The ore
roasting chamber is provided with stirrers upon arms operated by means of carriers
outside the roasting chamber proper; that is to say, the arm which carries the
stirrers extends through a longitudinal slot in the wall of the roasting chamber,
whereby all the impelling mechanism is removed from the direct action of the hot
products of combustion, and is thus protected against injury by the heat. The
impelling mechanism for the stirrers is in the form of carriers operated auto-
matically from a continuous cable travelling upon sheaves adjacent to the carriers,
the construction being such that each carrier comes to rest upon reaching the open
space above mentioned. In this open space each carrier is advanced at intervals
by the impact of the one immediately following so that by the time a carrier and
its attendant parts again enters the roasting chamber it has had sufficient time to
cool, and to receive any attention in the way of repair that it may require. Just
before re-entering the roasting chamber, the carrier automatically grips the cable
and is carried forward continuously and at uniform speed until it strikes the
rearmost carrier in the open space, advancing all the carriers at rest oue step, and
coming to rest itself through the action of automatic mechanism which releases its
grip upon the cable. The carriers travel in a direction contrary to that of the
products of combustion which has advantages, though the directions may be the
same if desired. The ore is fed upon the hearth of the roasting chamber at
the entrance of the latter and is advanced intermittingly by the action of the
stirrers to the terminus of the hearth where it is discharged. One of the features
of my present invention relates to automatic feeding mechanisin by which the ore is
deposited at proper intervals and in regulated quantities upon the hearth and
spread uniformly upon the latter to be acted upon by the stirrers. The foregoing
will suffice to convey a general comprehension of the nature and objects of my
invention, and will serve as an aid in understanding the description of the specific
construction by which the desired results are produced. All the various
mechanisms are illustrated in detail in the accompanying drawings, in which-
Figure 1 is a broken sectional plan-view, partly diagrammatic, of the roasting
chamber, furnaces and other details of the structure;
-
Figure 2, a broken view in side elevation of the plant, on a reduced scale;
Figures 3, 4, 5 and 6, enlarged sections taken respectively on lines 3, 4, 5 and 6
of Figure 1, and viewed as indicated by the arrows;
Figure 7, a section taken on line 7 of Figure 8, showing one of a series of
similar openings, in the inner circular wall of the structure, which contain the cable
guiding and supporting sheaves :
°

page_text: Figure 8, a section taken on line 8 of Figure 7;
Figure 9, an enlarged broken top plan view of the forward or gripping-end
portion of one of the stirrer arm carriers;
Figure 10, a side elevation of the part shown in Figure 9, with the cable gripping
jaws opened;
Figure 11, a view of the same gripping mechanism with parts removed to disclose
features which would otherwise be hidden;
Figure 12, a view similar to Figure 11, but showing the gripping jaws closed;
Figure 13, a broken partly sectional view of the end of the part shown in
Figures 9 and 10;
Figure 14, a cross section of the gripping mechanism taken on line 14 of
Figure 12 and viewed as indicated by the arrow;
Figure 15, a section taken on line 15 of Figure 16 and viewed as indicated by
the arrow;
r'
Figure 16, a broken side view of one of the stirrer arms;
Figure 17, a broken view of the underside of a stirrer arm;
Figure 18, a side elevation of the ore-feeding mechanism; and Figure 18ª, a
broken plan view of a detail thereof; Figure 19, a vertical section of the
same; and
Figure 20, a broken plan sectional view of the structure taken at the open space
between the ore-receiving and discharging ends of the roasting chamber.
The furnace structure A Fig. 1 is formed with an outer circular wall A', an
inner wall A, concentric with the wall A', a hearth B, which may be upon a
bed B¹ Figs. 5 and 6, and a roof A³, arched on its underside. C is the roasting
chamber, flanked on opposite sides by chambers C₁ C', from which it is separated
by longitudinally slotted walls or partitions t s. The roasting chamber extends
from, in Figures 1 and 2, around an almost complete circle to ¹, in the same
figures, and the break between the points is an open portion of the structure
forming a cooling space, D, through which access may be had to the circular
space inclosed by the wall A'. E, F, G and H Fig. 1, are furnaces, located at
intervals, as indicated, around the outer wall A'. Each furnace may be con-
structed as shown in Figure 5, with an ash-pit and combustion chamber r³,
divided from each other by an inclined grate 2; the ash-pit having a draft and
cleaning opening and the combustion-chamber a fuel feed opening . Each
fire-chamber has a flue leading to the roasting chamber C through the roof of
the latter. The initial furnace E Figs. 1, 2 and 4 is adjacent to the end of the
roasting chamber; and near the end of the roasting chamber is a flue I which
extends across the upper side thereof to a chimney I¹. Between the roasting
chamber and flue I are a series of openings 12 provided with dampers I³ having
operating rods 1' extending to the outside of the structure. The hot products of
combustion from the furnace E pass around, through the roasting chamber, to the
flue and chimney, being reinforced on the way by the hot products of combustion
from the furnaces F, G and H, respectively.
Extending at short intervals through the wall A2, at the hearth B, is a series of
openings into which are fitted boxes
p. Each box (see Figures 7 and 8) is
formed with a base-plate p', side plates p and top-plate p³, and is firmly incased in
the wall. Fastened to the base plate p' of each box is a vertical pin p upon
which a guide-wheel q' preferably in the form of a sheave is mounted to rotate in
the horizontal plane. The sheaves g' project a short distance into the chamber C¹,
and the base plates p' extend across or nearly across the chamber to the
partition Figs. 5 and 6. At the inner side of the box is a removable back plate p³
which extends from the top plate down nearly to the sheave. The base plates are
constructed to afford rail-chairs on which is mounted a continuous track rail o.
Extending around the partitions in the chamber C2 is a continuous rail o
Figs. 1, 2, &c.
At the break or open space D is a frame work D' Fig. 1, which may or may
not be inclosed, and which supports the ore feeding mechanism hereinafter

page_text: described. In the space inclosed by the furnace structure is an engine indicated
at K, from which the various moving parts of the construction are operated.
Journaled in the frame work D' are a drive-shaft n, which is belted to the engine,
not shown, a shaft n', belted to the shaft n, and a shaft n² carrying a gear wheel n³
driven by a pinion n on the shaft n'. A wall A4 forming a continuation of the
wall A² extends, to the height of the plane of the openings q, across the break D,
and supports sheaves q¹, as indicated in Figures 1 and 20, which complete the
circle described by the series of sheaves. The wall A* also supports the rail o
where the latter extends across the break. Forming part of the frame work DI
are beams m, resting at their inner ends on the wall A', and supported at their
outer ends upon posts m¹. The beams m support the track o' where it extends
across the break D.
L Figs. 1 and 20 is an endless cable which extends around the wall A³, in the
chamber C, against the sheaves q¹. The shaft n² in the frame work carries a
drum 1, and below and parallel with the shaft n' is a shaft carrying a drum,
which extends at the lowest part of its circumference in the plane of the sheaves q'.
From the sheave g¹ at one side of the drum l, the cable passes, as indicated in
Figure 2, under the drum to and over the drum l, thence under a weighted
pulley back to and over the drum I, and thence down to and under the drum /
to the sheave q' at the opposite side. The weighted pulley is suspended from
the cable and thus operates as a tightener for the latter.
The
M M Fig. 1, are the stirrer carrier frames, which are of L-shape, each com-
prising a head-bar M' Figs. 9, 10 and 14, and an arm M2 Fig. 5,-&c. The head-
bar M³, may be T-shaped in cross-section and curved longitudinally to conform
approximately to the circle described by the track-rail o. It is provided at opposite
ends with grooved wheels k Figs. 5, 9 &c., which travel upon the rail o.
partitions ts Figs. 1, 5 and 6 are separated by longitudinal slots t¹s just large
enough to permit the arms M2, which extend from the chamber C₁ across the
roasting chamber to the chamber C², to move without obstruction from the
partitions. At the ends of the arms M² are grooved wheels k¹ which travel upon
the track o¹.
Near the forward end of each head-bar M' is a cable gripping mechanism M*
Figs. 9 and 10. The gripping mechanism comprises a fixed part, formed with two
side-plates ii secured to the side of the bar M¹ and a cross plate or bar ¹ which
forms the upper gripping jaw, and a movable part comprising a plate h which
slides in vertical guide grooves 22 in the plates i, and has a flange h¹ at its lower
edge forming the lower gripping jaw. Through the plate h is an opening ² of the
form shown partly by dotted lines in Figures 10 and 11, and by full lines in
Figure 12. On the bar M¹ is a bearing ³ Fig. 14 for a short horizontal rock-
shaft. The shaft h* extends through the opening h² in the plate h, and carries,
adjacent to the plate h, an upward extending switch finger h, and, at the opposite
side of the bar M', a downward extending switch-finger. In the opening 2 is
a link Figs. 10 and 11 pivotally connected at one end to the finger h³ at h³, and
pivotally connected at its opposite end to the plate hat . In the open space D
Figs. 1, 2 and 20 near the end of the roasting chamber is a stop y Figs. 12 and 20
in the path, when the gripping jaws are closed, of the switch-finger h; and in the
open space D near the end of the roasting-chamber is a stop y Figs. 10 and 20,
in the path, when the gripping-jaws are open, of the switch-finger h³. In the
movement of a stirrer frame M, as hereinafter described, when it enters the open
space D, its switch finger he strikes the stop y, causing the shaft h to rock, to turn
the switch-finger to the raised position shown in Figure 10, and draw down the
link and plate to open the gripping jaws; and in the further progressive
movement of the stirrer frame toward the end of the roasting chamber, as
hereinafter described, the switch finger strikes the stop y', turns the rock-
shaft and finger to the positions
Figures 12 and 14, forcing
up the link h' and plate h to close the
The jaws of the gripping
shown in
jaws hi.

page_text: mechanism are in position to engage the cable as they close, and in opening they
release the cable.
The switch-finger / Figs. 9 and 10 is provided on its upper end with teeth 10
which are engaged by a pawl h pivoted on the head M¹, the effect of which is to
insure the holding of the switch finger and attendant mechanism in gripping position
after it has been acted upon by the stop y. Just before reaching the stop y the
pawl is released through the medium of the rod 12 which is tripped by impact
with the stop y, thus permitting the parts to be thrown out of gripping position
when the finger * comes into contact with the stop y. For this purpose the rod h¹
is pivotally connected to the pawl h and projects obliquely downward to a point
slightly in advance of the finger 4 where it is pivotally connected to a wiper h¹³
Figs. 10, 11 and 12 pivoted on the fixed jaw i¹. Thus when the wiper comes into
contact with the stop y the pawl h" is lifted out of engagement with the teeth, and
it drops back to its normal position when the stop has been passed.
The arm M Figs. 5, 15 and 16, of each stirrer frame, comprises a bar g which is
fastened at one end to the bar M', preferably midway of the length of the latter,
extending therefrom at a right angle, to the track o' upon which its wheel k¹ travels
as before stated. In the annular space between the circles described by the
partitions ts, the bar g is provided with, say, three clips g¹ which extend across the
top and down the sides of the bar, and are formed below the plane of the under side
of the bar with key openings 92. Extending over the bar 9 and clips g¹ is a
shield 93, held in place by bolts g' which pass across the under side of the bar g.
The stirrer blades fare fastened to angle-iron braces f¹ secured to the under-surface
of a bar f Figs. 15 to 17. The stirrer blades extend parallel with each other and
obliquely with relation to the bar f. The bar f2 fits, between the sides of the clips,
against the cross-bolts g, and is held firmly in place by keys f³ driven across its
under surface through the key-openings 2.
The ore to be roasted may be conveyed to the furnace in dumping cars (not shown)
traveling upon a track X Fig. 2, above the furnace, and which enters the frame-
work D. Below the dumping position of the cars is a hopper P. The lower end of
the hopper is closed by a wheel P¹ Fig. 19, mounted upon journals in the frame-work
to rotate in the vertical plane, and provided lengthwise with radial partitions
affording segmental pockets P', open at the circumference and closed at the ends.
Around the wheel at one end is a ratchet P³ Fig. 18. Below the wheel P¹ and
pivoted upon a shaft e is a dumping lever R, one arm of which, e¹, carries an
adjustable weight, e², the other arm e being free. Integral with the lever R is a
fan-shaped platform R¹, held by the counterweight e normally in the horizontal
plane across the under side of the wheel P. Rotating in the frame-work is a shaft
carrying a crank e, and pivoted at one end to the crank is a pawl e, which at its
free end engages a tooth of the ratchet P³. Pivoted at one end to the arm e¹ of the
lever and at its opposite end to the pawl e is a link e. The lever R swings from
the position shown by full lines in Figure 18, wherein the platform R' extends across
the underside of the wheel P¹ and the pawl e engages the ratchet P³, to the position
indicated by dotted lines, wherein the platform R₁ rests against a stop e on the
frame-work, the pawl is out of engagement with the ratchet, and the arm e³ extends
downward into the path of the stirrer arms M².
In operation the ore to be roasted is dumped into the hopper P and fills those
pockets P² of the wheel P¹ which at the time register with the discharge end of the
hopper. The crank e* rotates continuously and causes the pawl with each revolution
to reciprocate and move the wheel around the distance of one tooth of the ratchet P³.
As a pocket passes across the hopper it is filled with ore which as the pocket
leaves the hopper is dumped upon the platform R¹. When sufficient ore has been
deposited upon the platform to overcome the weight e², the lever upsets, and the
ore is discharged from the platform R' upon a stationary inclined platform R² which
terminates over the bearth near the end of the roasting chamber just above the
path of the stirrer arms. The lateral edges of the platform R¹ diverge whereby it

page_text: is widest at the discharge end, and on the surface of the platform are ribs forming
the said surface into a series of radially diverging chutes, as shown in Fig. 18,
which spread the ore as it runs therefrom over the platform R. The latter
platform as shown in Fig. 1, is also formed with diverging chutes causing the ore
to be distributed uniformly across the hearth. When the lever R is upset as
described, the pawl e' is raised, through the medium of the link e, and the wheel P¹
remains stationary. The weight e is swung to a point above the fulcrum of the
lever whereby the latter remains balanced in its upset position with its arm e
extending into the path of the stirrer arms as before described. In the movement
of a stirrer arm below the lever, it impinges against the arm e³ and turns the lever
until the weight e² overbalances the latter and swings the platform R' to the
horizontal plane, and the pawl into engagement with the ratchet P. By adjusting
the weight e upon the lever, the quantity of ore discharged upon the hearth with
each operation may be regulated, and the frequency of the charges may be regulated
by timing the travel of the stirrer arms, as hereinafter described.
The cable travels continuously, and two, four, six or more stirrer carrier frames
may be employed, as desired. The stirrer blades are set obliquely to their direction
of travel, the blades of alternate, that is to say, every second one of the carriers
pointing in the direction of the partition t and the blades of the intervening carriers
toward the partitions, this arrangement being usual in furnaces of this character.
At the end of the roasting chamber is a vertically swinging self-closing door,
and between the furnace E and end a are two similar doors z¹ 22 as shown in
Figs. 3, 4 and 20. When a stirrer frame grips the cable it strikes against and opens
the door, (which closes when released) and moves into the furnace, carrying in the
ore deposited upon the hearth by the feed. In Figure 1, two stirrers are shown at rest
in the open space D, one just released from the cable and the other ready to engage
the latter. When a stirrer frame advances from the end it strikes the rearmost
stirrer in the open space, and advances it and the foremost stirrer until the latter
grips the cable and advances into the furnace. In practice the stirrers may follow
each other say one minute apart, causing the feed mechanism to deposit ore upon
the hearth at intervals of a minute and each stirrer to remain in the open space two
minutes to cool. The time may of course be varied as desired. The construction
of the stirrer arms gives an air-space around the bar g Figs. 15 and 16 except at the
points where the clips g' and bolts intervene, the bar g is thus protected from the
heat of the roasting chamber, and as the shield 93 is cooled off regularly at the open
space, as described, the stirrer-arms will last an indefinite time. In the event of
any of the stirrer blades becoming seriously injured by the heat of the roasting-
chamber or contact with the ore, the bar f2 carrying the blades may be quickly
removed, when the stirrer reaches the open space, by knocking out the keys 3, aud
replaced by another barf without stopping the operation of the stirring mechanisms.
The partitions ts serve to shield the chambers CC from the hot products of
combustion, and to protect the cable, track-rails and end portions of the stirrer
carrier-frames from the heat. The cable tensioning mechanism described should
serve to maintain the cable taut. As a safeguard against binding of the cable, in
the event of its becoming slack at any time and dropping from the sheaves g', I
provide upon each base plate pl, beyond the back plate p³ and below the sheave, an
inclined guard projection p Fig. 7, in the arc of the circle described by the lower
edge of the sheave and close to said edge, upon which the cable will drop in the
event of its leaving the sheave, and which will guide the cable to the sheave when
the slack is taken up.
When the ore has been advanced by the stirrers around the roasting chamber it
may be discharged through an opening Z Fig. 4, in the hearth and into cars which
move upon a track Z' below. As the stirrers pass from the roasting chamber the
door closes before the door 2 opens and undue access of air is thus prevented.
In the roof of the roasting chamber adjacent to each furnace is an opening d Figs. 1
and 4, closed by a removable lid. In the event of the accumulation of matte at a
furnace a bar may be inserted through the adjacent opening d and the matte

page_text: loosened. This is a very desirable feature particularly when lead ores are to be
roasted. The openings are placed adjacent to the furnaces because those are the
hottest parts of the roasting chamber and where the matte would form.
The construction of furnace shown is the preferred one for affording a longi-
tudinally slotted wall by which the carrier for the stirrer arms is shielded from the
direct action of the hot products of combustion; but it will be obvious that any
construction which will bring the carrier outside the roasting chamber and afford a
longitudinally slotted wall for the passage of the stirrer arm, and providing at the
same time proper support for the portions of the furnace above the slot with proper
provision for preventing undue ingress of cold air would be the mechanical equivalent
of the construction shown and above described.
Obviously also the number of reinforcing furnaces employed may be governed by
circumstances and the engine located in such position as may be found most
convenient, for example, outside the furnace structure instead of inside as shown.
In order to guard against injury to the furnace by expansion and contraction
under the wide variations of temperature to which it is subject, I prefer to construct
it in sections which when the furnace is cool do not quite meet. When, however,
the furnace is heated, producing slight elongation, the sections close nearly or quite
together. Any crevices that exist at the junctions to Fig. 1, of the sections may be
closed by means of fire clay or otherwise. The crevices in the hearth at the junction
of sections may be closed by fire-brick w¹ (Fig. 4) set loosely in the bed B' beneath
the hearth.
Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed, I declare that what I
claim is :-
1. In combination with a curved ore roasting furnace, a longitudinally slotted
wall at the side of the roasting chamber, an endless cable mounted upon a series of
guide-wheels located at intervals throughout the length of the furnace adjacent to
the slotted wall, power mechanism for moving the cable, a traveling carrier adjacent
to the cable, connecting means between the carrier and the cable, and an arm
projecting from the carrier through the slot of the wall over the hearth and carrying
stirrers, substantially as described.
2. In combination with a curved ore-roasting furnace, a longitudinally slotted
wall at the side of the roasting chamber, an endless cable mounted upon a series of
guide wheels located at intervals throughout the length of the furnace adjacent to
the slotted wall, power mechanism for moving the cable, a traveling carrier
adjacent to the cable, automatic mechanism upon the carrier for gripping and
releasing the cable at predetermined points in the course of the carrier, and an arm
projecting from the carrier through the slot of the wall over the hearth and
carrying stirrers, substantially as described.
3. In an ore-roasting furnace, the combination with the roasting chamber,
chambers CC2 on opposite sides thereof, heat generating furnace communicating
therewith, and means for stirring and advancing the ore along the roasting
chamber, comprising carriers running in the chambers C¹ C2, a stirrer arm mounted
upon the carriers and extending across the roasting chambers, stirrer blades on the
stirrer arm, and means for moving the carriers, of an opening d in the top of the
roasting chamber adjacent to the generating furnace and provided with a door,
substantially as and for the purpose set forth.
4. In combination with a curved ore-roasting furnace a longitudinally slotted
wall at each side of the roasting chamber, an endless cable mounted upon a series
of guide-wheels located at intervals throughout the length of the furnace adjacent
to one of the slotted walls, power mechanism for moving the cable, a traveling
carrier adjacent to the cable, connecting means between the carrier and cable,
an arm projecting from the carrier through the slots in both walls, stirrers upon
the arm, and a traveling support at the free end of the arm, substantially as
described.

page_text: 5. In combination with a curved ore-roasting furnace having an open portion
between the terminals of the roasting chamber, and a longitudinally slotted wall at
the side of the roasting chamber, an endless cable mounted upon guide-wheels.
located at intervals around the entire circuit of the structure, power mechanism for
moving the cable, traveling carriers on a track extending throughout the whole
circuit of the structure adjacent to the cable, an arm extending from the carrier
through the slotted wall over the hearth and carrying stirrers, and automatic
mechanism upon the carriers for gripping the cable at the entrance end of the
roasting chamber, and releasing it at the exit end thereof, substantially as
described.
6. In combination with a curved ore roasting furnace having an open portion
between the terminals of the roasting chamber, and a longitudinally slotted wall at
each side of the roasting chamber, a track adjacent to the outer side of each slotted
wall and extending throughout the whole circuit of the structure including the
open portion, traveling carriers upon one of the tracks, a stirrer arm extending
from each carrier through both slotted walls and mounted at its free end upon a
traveling support on the other track, an endless cable mounted upon guide-wheels
located at intervals throughout the whole circuit of the structure, adjacent to the
carrier track, power mechanism for moving the cable, and automatic means upon
each carrier for gripping the cable at the entrance end of the roasting chamber and
releasing it at the exit end thereof, substantially as described.
7. A curved ore roasting furnace having its masonry formed in sections which
do not meet when the furnace is cool, substantially as and for the purpose set
forth.
8. The combination with an ore-roasting furnace A having a slotted wall at the
side of the roasting-chamber, open portion between the terminals of the roasting-
chamber and stops y y' at the open portion, endless cable adjacent to the slotted
wall, power mechanism for moving the cable, and traveling carriers having stirrer
arms projecting into the roasting chamber through the slotted wall, of mechanism
upon each carrier for gripping the cable at the entrance end of the. roasting
chamber and releasing it at the exit end thereof, comprising a stationary jaw, a
rock-shaft provided with oppositely extending switch fingers to strike the stops on
the furnace, a movable jaw and a link connection between the rock-shaft and
movable jaw, substantially as described.
9. The combination with an ore-roasting furnace A having a slotted wall at the
side of the roasting-chamber, open portion between the terminals of the roasting-
chamber and stops y y at the open portion, endless cable adjacent to the slotted
wall, power mechanism for moving the cable and traveling carriers having stirrer
arms projecting into the roasting chamber through the slotted wall, of mechanism
upon each carrier for gripping the cable at the entrance end of the roasting
chamber and releasing it at the exit end thereof, comprising jaws h'i', a switch
finger connected with the jaws and operating by contact with the stop y' to close
the jaws, a switch finger connected with the jaws and operating by contact with
the stop y to open the jaws, and automatic locking mechanism for the jaws when
closed released by engagement with a stop just before the switch finger strikes the
stop y, substantially as described.
10. The combination with the traveling carrier, of a stirrer arm comprising a
bar 9, fixed to the carrier, and a bar f³, carrying a series of oblique stirrer blades,.
and clamping means for fastening the bar f removably against the bar g,.
whereby the series of stirrer blades upon a stirrer arm may be simultaneously
and quickly attached and detached, substantially as and for the purpose set
forth.
11. The combination with the traveling carrier, of a stirrer arm comprising
a bar g fixed to the carrier, a shield secured around three sides of the said bar
and separated therefrom by an air space, and a bar carrying stirrer-blades and
detachably connected to the face of the bar g, substantially as described.
12. The combination with the traveling carrier, of a stirrer arm comprising

page_text: a bar g fixed to the carrier, a shield secured around three sides of the said bar and
separated therefrom by an air-space, and a bar carrying stirrer blades detachably
connected to the bar g, out of contact therewith, whereby an air-space intervenes
between them, substantially as described.
13. The combination with the traveling carrier, of a stirrer arm comprising a
bar g fixed to the carrier, clips g¹ upon the bar, and a bar f2 carrying stirrer
blades and keys passing through the clips for detachably connecting the bar f' to
the bar g, substantially as described.
14. In combination with an ore-roasting furnace having stirrers moving through-
out the length of the hearth, a feed device for the ore arranged to be operated
by the movement of the stirrers to discharge ore upon the hearth, substantially as
described.
15. In combination with an ore-roasting furnace, intermittent feed mechanism
for discharging ore upon the hearth comprising a counterbalanced upsetting
platform, to receive the ore, a revoluble wheel having pockets receiving the ore
from an ore supply and discharging it upon the platform, and means for stopping
the wheel when the platform is upset by the weight of the ore deposited thereon,
substantially as described.
16. In combination with an ore-roasting furnace, intermittent feed-mechanism
for discharging ore upon the hearth, comprising an upsetting platform to receive
the ore provided with an adjustable counterbalance, a revoluble wheel having
pockets receiving the ore from an ore-supply and discharging it upon the platform,
and means for stopping the wheel when the platform is upset by the weight of the
ore deposited thereon, substantially as described.
Dated 8th day of May 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.