Year: 1898

page_text: Date of Application, 28th Dec., 1898-Accepted, 11th Feb., 1899
I, JOHN BROWN FRANCIS HERRESHOFF, of 19, Pierrepont Street, Brooklyn, in the
County of Kings and State of New York, United States of America, Chemist, 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 roasting furnaces and has for its special object to improve
the means for connecting the arms to the central vertical shaft of such furnaces.
In furnaces heretofore devised it has been proposed to employ a hub rigidly fastened
to the vertical shaft and to provide the said hub with means for readily being
engaged or disengaged by the removable arms Such a structure, however, 18
imperfect, for the reason that the hubs in the course of time deteriorate under the
fierce heat employed and will no longer remain firmly fixed to the shaft nor pro-
perly receive and support the removable arms
My invention is designed to avoid this defect by providing means whereby the
stirrer arms may be removably engaged directly with the hollow shaft through
which air passes, in order that it may be artificially maintained at a lower tem-
perature than the general temperature of the furnace, whereby the junction of the
shaft and arms will not be exposed to the terrible heat to which they have hereto-
fore been subjected.
My invention will be understood by referring to the accompanying drawings in
which
Figure 1 is a transverse vertical section of a 1oasting furnace embodying my
invention;
Figure 2 18 an enlarged sectional view of one arrangement whereby the
removable arms are mounted directly to the shaft, the section being taken on
line 2-2 of Figure 3,
Figure 3 is a vertical section taken on line 3-3 of Figure 2,
Figure 4 is a section on line 4 4 of Figure 3, showing the sharpening of the
lower edge of the side webs of the arms. This drawing shows one embodiment of
my invention
In the drawing, A represents the furnace which is provided with the usual roast-
ing floors B and a shaft C This shaft C is the driving shaft which carries the
stirrer arms and is hollow in order to allow circulation of air This shaft C is
driven in any suitable manner from a shaft D and is provided with apertures & for
the influx of a cooling medium such as air at the lower part and is open or per-
forated at the top for the escape thereof The hollow shaft is shown as provided
with inwardly extending plates oi partitions c¹ c³ ³ c³, so as to form inwardly extend-
ng passages or pockets The upper partition 3 18 shown as provided at its centre
with a recess for the reception of lugs on the stirrer aims, as will be explained
The lower partition serves also to guide the sture arms as they enter said
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pockets The form of stirrer arm E shown 18 preferably provided with teeth e
in the usual manner and with a toe or lug el adapted to enter the recess c³ in the
It will be observed that the sturer aim E is of a
passage or pocket in the shaft
iectangular box shape and that the lower web or aide thereof rests upon the lower
edge of the passage through the shaft at the periphery thereof and is cut away 5
at so that the said lower web does not extend entirely to the extreme inner end
of the arm The side webs e, as it will be seen, extend beyond the lower web e
and are sharp, as will be seen by an inspection of Figure 4, in order that they may
readily enter the passage or pocket even when the same is partly choked up with
It will be 1
dust and chemicals lying in the bowed portion of the partition c
observed that the partitions forming the pockets within the shaft do not prevent
the flow of air or other cooling fluid through the said shaft, but the air can freely
circulate around the said pockets thereby cooling the same and the ends of the
arms contained within the passage or pocket When the starrers extend diametri-
cally from a continuous passage as shown, their inner ends may substantially abut
The arms E become imperfect during the operation of the furnace either by
deterioration or destruction of the teeth, or for other causes and it is quite impoi-
tant to be able to withdraw a defective arm and insert a perfect one without stop-
ping the furnace a longer time than a moment or so, as such furnaces require
considerable time to cool and stopping the same for repairs is extremely costly
By my invention, however, when an arm becomes defective for any reason, it is
merely necessary to lift up its outer end, thus 1ocking the arm on the edge of,
thereby removing the lug e from the recess c5 80 that the arm may be removed
while momentarily stopping the furnace and without cooling it down and a perfect
arm inserted by a reverse operation to that described for withdrawing the arm
As
have stated before it has heretofore been attempted to produce a practical roast-
ing furnace by providing the same with removable stirrer arms, but in such cases
it has been the custom to provide the vertical shaft with hubs for the reception of
the arms which hubs were more or less flimsily secured to the shaft, so that when
subjected to the high heat employed they very shortly became disconnected from
the shaft This defect I obviate by securing the arm in pockets of suitable form
in the hollow shaft itself and cooling the junction of shaft and arma It will be
noted that I have provided a means for feeding ore or other chemicals to the fur-
nace comprising a hopper 1, a receiving pan 2, from which a chute 3 depends A
slide rod 4 sliding in suitable bearings 5 is provided with a clearer 6 adapted to
clear or remove ore from the pan 2 The slide rod 4 receives its motion from a
frame 7 provided with lugs 10 acted upon by a bowl 8 carried upon a collar 9 on
the shaft It will be obvious that as the shaft rotates it will reciprocate the slide
rod 4 back and forth and thereby clear the pan of its contents at each reciprocation,
so that a continuous regulable feed is provided for the furnace
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 In a roasting furnace, the combination of a hollow shaft having inwardly
extending pockets, combined with stirrer arms entering said pockets with means
substantially as described for locking the stirrer arms in said pockets and with
means to permit circulation of a cooling medhum through said shaft
2. In a roasting furnace, the combination of an upright hollow shaft provided
with interior passages or pockets opening to the outside of the shaft, the top
walls of which are recessed, with stirrer arms adapted to enter the passages or
pockets and provided with lugs entering the said recesses and with means for pass-
ing a cooling fluid through the shaft and around the passages or pockets thei ein
to cool the junction of the stirrer arms with the shaft
3. In a roasting furnace the combination of a hollow shaft having passages
extending therethrough laterally, stirrer arms entering the said passages from

page_text: opposite sides and adapted to abut against each other within the passages and
means substantially as described for looking the said stirrer arms in said passages
and with means to permit circulation of a cooling medium through said shaft.
Deted this 28th day of December 1898.
A M. & WM. OLARK,
Chartered Patent Agents, 53, Chancery Lane, London.