Improvements in Furnaces for Heating Metal Bars and the like.
Year: 1898

page_text: Date of Application, 2nd Aug., 1898-Accepted, 29th Oct., 1898
COMPLETE SPECIFICATION.
Improvements in Furnaces for Heating Metal Bars and the like.
I, EDWIN NORTON, of Maywood, in the County of Cook and State of Illinois,
United States of America, Manufacturer, 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 furnaces for heating sheets and bars of
steel or other metal preparatory to rolling the same into thin sheets for tin plate
or other purposes.
The object of my invention is to provide a furnace of an efficient, simple and
durable construction, by means of which such sheets or bars may be cheaply, rapidly
and uniformly heated so that when delivered from the furnace to the rolling mill
certainty and uniformity of action may be secured and danger of breaking the rolls
or injuring the mill prevented.
My invention consists in the means I employ to accomplish this result, that is to
say, it consists essentially in the combination with the heating chamber of the
furnace of a rotary rack comprising a central shaft and a series of radial arms
projecting therefrom and upon which the sheets to be heated are placed in the
radial spaces or receptacles between the different sets or rows of radial arms, and by
which the sheets or bars are carried successively to different positions in the furnace
as the rack is turned to bring each successive set of arms into position opposite
the furnace door for removing the heated sheets or bars and putting in fresh ones.
The bottom of the furnace is semi-circular or semi-cylindrical, and supports the
sheets or bars in the lower half of the rack in position between the radial arms
as the rack revolves. The rotation of the rack in the furnace chamber keeps the
sheets or bars in a series of separated radial planes or positions with open spaces.
between, thus securing efficient and economical heating action, and as the rack
rotates each radial set of arms brings its load of sheets or bars successively into all
the different positions, thus giving a uniform heating action upon each and every
batch or charge of sheets or bars put in one after another as each set of radial
arms is brought opposite to the door of the furnace. The radial sheet or bar
holder or rack is preferably rotated by a power driven shaft or pulley, which is
momentarily clutched at intervals to a shaft geared to the shaft of the rack so as
to give the necessary step by step movement to the rack, the clutch automatically
disengaging as soon as the movement is completed.
In the accompanying drawings, forming a part of this specification, and in which
similar letters of reference indicate like parts throughout the figures.
Fig. 1 is a plan view of a sheet or softening furnace embodying my invention,
the top or cover portion of the furnace being removed; Fig. 2 is an end elevation;
Fig. 3 is a vertical section on the line 3-3 of Fig. 1; Fig. 4 is an enlarged detail
transverse sectional view of the rotary rack or sheet holder; Fig. 5 is an end view
showing the modified form of rack employed when the furnace is used for heating
bars, which are thicker but much smaller in width and length than the sheets;
Fig. 6 is a detail view of the clutch; and Fig. 7 is a section on line 7-7 of Fig. 6.

page_text: In the drawing A represents the furnace, the same being of any suitable or
well known construction of sheet or softening furnace or bar furnace. A¹ is the
heating chamber of the furnace, A' its fire cliamber, A³ the grate, A' the door
through which fuel is put into the fire chamber above the grate, and As the door
or opening through which the sheets or bars are put in and taken out of the heating
chamber of the furnace.
B is a rotary rack or holder for receiving and holding the sheets or bars in the
heating chamber of the furnace and moving or conveying them successively into
different positions therein, so that they may be economically and properly and
uniformly heated or softened with regularity and certainty, and by which the
heated sheets or bars are finally returned into position opposite the heating chamber
door so that they may be conveniently removed from the furnace. This rotary rack
or holder for the sheets or bars consists, preferably, of a shaft B₁ provided with
series of sets or rows B2, of radial arms B³, forming a series of radial spaces or
receptacles B for the sheets or bars between the several rows or sets of radial arms,
the arms separating the sheets or bars in one receptacle from those in another, thus
leaving free open radial spaces between the several receptacles and the sheets or
bars therein. to enable the flame and heat to efficiently and properly act. The
shaft B¹ extends through the two end walls a a of the furnace and is journaled in
suitable bearings outside the furnace, and it is given a step by step rotary move-
ment to bring each successive set or row B³ of radial arms B3 in turn in line with
the feed door or opening A5, by means of a power driven shaft or pulley C, which
is adapted to be connected by a clutch D D' with a shaft E, which is provided with
a worm F that meshes with a worm gear b¹ on the shaft B¹. The member D¹ of the
clutch which is carried by the shaft E is provided with a slide Ds actuated by a
spring and which engages the notch of the member D, said slide 12 being
provided with a pin or projection d which is engaged by a cam or shoe d' which
is connected to the clutch operating lever or rock shaft d³. One revolution of the
worm shaft E turns the rack B the radial space or distance between the successive
sets or rows of radial arms B³ on the rack and as the clutch mechanism permits the
shaft E to make but one turn each time the clutch lever is operated, each set or
row of arms B³ is thus successively brought into position opposite the door A' BO
the heated sheets or bars may be removed therefrom and fresh ones put in place
thereon. Each and every load or charge of sheets or bars successively put into the
furnace thus undergoes the same precise operation and receives the same precise
treatment or heating action, and are therefore each and all heated with great
uniformity and regularity, thus removing all danger of breaking the rolls or doing
other injury to the rolling mill in the rolling operation, which heretofore has been
a great difficulty in tin plate rolling mills.
The mechanism above described and shown in the drawing is that which I
prefer to use for giving the necessary step by step movement to the rotary rack
or holder B, but my invention is not limited to any particular mechanism.
The heating chamber A¹ of the furnace is provided with a curved bottom A6,
preferably composed of curved or semi-circular iron ribs a¹ set at intervals and
filled in between with fire brick or refractory material a³. This curved bottom or
its ribs a¹ serve to hold the sheets ar bars in the lower half of the rotary rack in
position between the radial arms, as the rack revolves.
The shaft B and its radial arms B³ may if desired be made hollow, so that air or
water may circulate through the shaft and into the arms to increase their durability
or protect them from the heat. If it is desired to have water circulate through the
shaft its ends will be connected by stuffing boxes 66 with water supply and outlet
pipes. The radial arms B3 are preferably secured to the shaft by screw threaded
flanged bosses 62 and the arms are also preferably surrounded by protecting tubes
or coverings of refractory or non-heat-conducting material, held in place by
flanges on the caps or plugs 65 fixed on the ends of the arm B³.
Where my furnace is used for a sheet or softening furnace the length of the rack
or holder B should be somewhat greater than that of the sheets or packs of sheets to

page_text: be heated or softened, and the length of the radial arms somewhat greater than the
width of the sheets.
And when my furnace is used as a bar furnace the rack or holder may preferably
be of substantially the same dimensions, but in this case I prefer to provide the
rack or holder with double rows or sets of radial arms set parallel to each other,
as illustrated in Fig. 5, so that two or more of the narrow bars may be placed edge-
wise against each other in each radial space or receptacle B4, and also two or more
end to end lengthwise in each radial space or receptacle. The double rows of radial
arms will thus serve to hold all the bars properly in place edge to edge on top of
each other as the rack or holder revolves. This same double row arrangement of
the radial arms may also be used when the furnace is employed for heating or
softening the sheets, but owing to the larger size of the sheets it is not necessary
with the sheets.
A sliding door A6 closes the feed opening A5 through which the sheets or bars
are put in or taken out.
.
By my invention I am not only enabled to produce the important result of heat-
ing the sheets or bars with regularity and certainty to a uniform heat, but it also
results in a great saving of fuel us the heating action is more effectually applied
and distributed, and it also effects a very great saving in labor as it entirely dis-
penses with the necessity of moving the bars or sheets about in the furnace by
hand, as heretofore has been the practice.
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. In a sheet or bar heating furnace, the combination with the heating chambor
of a rotary rack having a horizontal shaft and rotating vertically in said chamber
and provided with a series of rigid radial receptacles for receiving and holding the
sheets or bars and conveying them in a complete circuit about the axis of said
rotary rack and thus cause them to receive the heating action of the furnace in
different radial planes and first with one side and edge uppermost and then with
the other side and edge uppermost, and means for keeping the sheets or bars in
position in said radial receptacles while being conveyed through the lower helf
circle of their orbit, substantially as specified.
2. In a sheet or bar heating furnace, the combination with the heating chamber
of the furnace provided with a door at one side for putting the sheets or bars in
and taking them out, of a rotary rack or holder in said chamber for receiving and
holding the sheets or bars, and conveying them in a complete circuit about the
axis of said rotary rack from said door back again to the same and thus cause them
to receive the heating action of the furnace in different radial planes and part of
the time with one of their edges uppermost and part of the time with their opposite
edges uppermost, and comprising a horizontal shaft provided with a series of sets
or rows of radial arms projecting therefrom, and means for keeping the sheets or
bars in position in said rotary rack while being conveyed through the lower half
of their circular orbit, substantially as specified.
3. In a sheet or bar heating furnace, the combination with the heating chamber
of the furnace, of a rotary rack or holder in said chamber for receiving and holding
the sheets or bars, and comprising a shaft provided with a series of sets or rows
of radial arms projecting therefrom, said heating chamber having a curved bottom
to hold or keep the sheets or bars in position between the sets or rows of radial
arms, substantially as specified.
4. In a sheet or bar heating furnace, the combination with the heating chamber
of the furnace provided with a door at one side for putting the sheets or bars in
and taking them out, of a rotary rack or holder in said chamber for receiving and
holding the sheets or bars and conveying them in a complete circuit about the
axis of said rotary rack from said door back again to the same and thus cause them
to receive the heating action of the furnace in different radial planes and part of the

page_text: time with one of their edges uppermost and part of the time with their opposite
edges uppermost, and comprising a horizontal shaft provided with a series of
sets or rows of radial arms projecting therefrom, and mechanism for imparting a
step by step rotary movement to said shaft, and means for keeping the sheets or
bars in position in sead rotary rack while being conveyed through the lower half
of their circular orbit, substantially as specified.
5. In a sheet or bar heating furnace the combination with the heating chamber
of the furnace provided with a door at one side for putting the sheets or bars in
and taking them out, of a rotary rack or holder in said chamber for receiving
and holding the sheets or bars and conveying them in a complete circuit about the
axis of said rotary rack from said door back again to the same and thus cause
them to receive the heating action of the furnace in different radial planes and
part of the time with one of their edges uppermost and part of the time with their
opposite edges uppermost, and comprising a horizontal shaft provided with a series
of sets or rows of radial arms projecting therefrom, and mechanism for imparting
n step by step movement to said shaft, said mechanism comprising a worm gear,
worn and a clutch provided with devices for automatically disengaging its men-
bers, and means for keeping the sheets or bars in position in said rotary rack while
being conveyed through the lower half of their circular orbit, substantially as
specified.
6. In a sheet or bar heating furnace, the combination with the heating chamber
of the furnace, of a rotary rack or holder in said chamber for receiving and holding
the sheets or bars, and comprising a shaft provided with a series of sets or rows
of radial arms projecting therefrom, said heating chamber having a curved bottom
to hold or keep the sheets or bars in position between the sets or rows of radial arms,
and mechanism for imparting a step by step rotary movement to said shaft, sub-
stantially as specified.
7. In a sheet or bar heating furnace, the combination with the heating chamber
of the furnace provided with a door at one side for putting the sheets or bars in
and taking them out, of a rotary rack or holder in said chamber for receiving and
holding the sheets or bars and conveying them in a complete circuit about the
axis of said rotary rack from said door back again to the same and thus cause
them to receive the heating action of the furnace in different radial planes and part
of the time with one of their edges uppermost and part of the time with their
opposite edges uppermost, and comprising a horizontal shaft provided with a series
of sets or rows of radial arms projecting therefrom, said shaft and radial arms
being hollow, and means for keeping the sheets or bars in position in said rotary
rack while being conveyed through the lower half of their circular orbit, sub-
stantially as specified.
8. In a sheet or bar heating furnace, the combination with the heating chamber
of the furnace provided with a door at one side for putting the sheets or bars in and
taking them out, of a rotary rack or holder in said chamber for receiving and hold-
ing the sheets or bars and conveying them in a complete circuit about the axis of
said rotary rack from said door back again to the same and thus cause them to
receive the heating action of the furnace in different radial planes and part of the
time with one of their edges uppermost and part of the time with their opposite
edges uppermost, and comprising a horizontal shaft provided with a series of sets
or rows of radial arms projecting therefrom, said radial arms having covering
tubes of refractory or non-heat-conducting material, and means for keeping the
sheets or bars in position in said rotary rack while being conveyed through the
lower half of their circular orbit, substantially as specified.
9. The combination with the heating chamber of a furnace provided with a
door opening through which sheets or bars may be removed from or delivered into
said chamber, of a rotary sheet or bar holder or rack mounted in said chamber
and provided with a series of radial receptacles for sheets or bars, and conveying
them in a complete circuit about the axis of said rotary rack from said door back
again to the same and thus cause them to receive the heating action of the furnace

page_text: in different radial planes and part of the time with one of their edges uppermost
and part of the time with their opposite edges uppermost, and means for keeping
the sheets or bars in position in said rotary rack while being conveyed through the
lower half of their circular orbit, substantially as specified.
10. The combination with the heating chamber of a furnace provided with a door
opening through which sheets or bars may be removed from or delivered into said
chamber, of a rotary sheet or bar holder or rack mounted in said chamber, and
rotating in a vertical plane on a horizontal shaft and provided with a series of radial
receptacles for sheets or bars, and conveying them in a complete circuit about the
axis of said rotary rack from said door back again to the same and thus cause them
to receive the heating action of the furnace in different radial planes and part of
the time with one of their edges uppermost and part of the time with their opposite
edges uppermost, and mechanism for turning said rotary rack or holder to bring
each of said radial receptacles opposite said door or opening, to permit the heated
sheets or bars to be removed from the rack or holder and fresh ones put in, and
means for keeping the sheets or bars in position in said rotary rack while being
conveyed through the lower half of their circular orbit, substantially as specified.
11. The combination with a furnace heating chamber provided with a door at
one side for putting the sheets or bars in and taking them out, of rotary rack or
holder mounted therein and comprising a horizontal shaft and a series of double
sets or rows of radial arms for receiving, holding and conveying sheets or bars
in a complete circuit about the axis of said rotary rack and thus cause them to
receive the heating action of the furnace in different radial planes and part of the
time with one edge uppermost and part of the time with the opposite edge upper-
most, and means for keeping the sheets or bars in position in said rotary rack
while being conveyed through the lower half of their circular orbit, substantially
as specified.
12. The combination with a furnace heating chamber, of rotary rack or holder
mounted therein and comprising a shaft and a series of double sets or rows of
radial arms, said chamber having curved ribs in its bottom to hold or keep the
sheets or bars in position between the sets or rows of radial arms, substantially as
specified.
13. The combination with a furnace heating chamber provided wtih a door at
one side for putting the sheets or bars in and taking them out, of a rotary rack or
holder mounted therein, and comprising a hollow horizontal shaft, and a series of
hollow radial arms projecting therefrom in a series of rows arranged in different
radial planes for receiving, holding and conveying sheets or bars in a complete
circuit about the axis of said rotary rack and thus cause them to receive the heating
nction of the furnace in different radial planes and part of the time with one edge
uppermost and part of the time with the opposite edge uppermost, and said shaft
being provided with stuffing boxes to connect the same with water supply pipes,
and mesans for keeping the sheets or bars in position in said rotary rack while
being conveyed through the lower half of their circular orbit, substantially as
specified.
14. The combination with a furnace heating chamber, provided with a door at
one side for putting the sheets or bars in and taking them out, of a rotary rack
or holder mounted therein, and comprising a hollow horizontal shaft, and a series
of hollow radial arms projecting therefrom in a series of rows arranged in different
radiad planes for receiving, holding and conveying sheets or bars in a complete
circuit about the axis of said rotary rack and thus cause them to receive the heating
action of the furnace in different radial planes and part of the time with one edge
uppermost and part of the time with the opposite eilge uppermost, and said shaft
being provided with stuffing boxes to connect the same with water supply pipes,
and tubes or coverings of refractory material surrounding said radial arms, and
means for keeping the sheets or bars in position in said rotary rack while being
conveyed through the lower half of their circular orbit, substantially as specified.
15. The combination with a furnace heating chamber provided with a door at

page_text: one side, for putting the sheets or bars in and taking them out, of a rotary bed for
holding the sheets and conveying them in a complete circuit about the axis of said
rotary rack from said door back again to the same and thus cause them to receive
the heating action of the furnace in different radial planes and part of the time
with one of their edges uppermost and part of the time with their
opposite edges uppermost, having a hollow horizontal shaft connected
with a water supply pipe, and means for keeping the sheets or bars in position in
said rotary rack while being conveyed through the lower half of their circular
orbit, substantially as specified.
६
EDWIN NORTON.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.