IMPROVEMENTS IN PORTABLE FORGES OR FURNACES, AND BLOWING APPARATUS
Year: 1874

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN PORTABLE FORGES OR FURNACES, AND BLOWING
APPARATUS." -A communication from abroad by De Witt Clinton
Baxter, of Philadelphia, Pennsylvania, United States of America.
Sealed the 9th October 1874, and dated the 12th May 1874.
PROVISIONAL SPECIFICATION left by the said Jolin Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 12th May 1874.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn. Fields, in the
County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN PORTABLE FORGES OR FURNACES, AND
BLOWING APPARATUS," a communication to me from abroad by De Witt'
Clinton Baxter, of Philadelphia, Pennsylvania, United States of
America, to be as follows:-
-
The first part of the Invention relates to the peculiar construction of
portable forges, described hereafter, with the view to the attainment of
simplicity, lightness, durability, and stability.

page_text: The second part of the Invention relates to the construction of portable
forges for use on board vessels, or for army uses, and other purposes; the
main feature of the Invention being the packing of the whole forge,
including legs and blowing appliances, in a box which forms part of the
forge, and which can be easily transported.
The third part of the Invention relates to the construction of a forge
for heating rivets in boiler shops, iron shipbuilding yards, &c.
The fourth and last part of the Invention relates to an improvement
in fan blowers made with the view of increasing their efficiency and of
obtaining an uniform blast.
To the hearth of the furnace, which is preferably made of cast iron,
are secured the upper ends of four legs made of wrought-iron tubes,
which are connected together by means of a socket adapted to the sides
of each of the legs, and arranged to receive one end of a light wrought-
iron tube, the opposite end of which fits into a similar socket adapted to
the opposite leg. A bolt passes through this tube and through both the
legs, and serves to secure the whole firmly together.
In securing the legs to the hearth the upper threaded end of the leg
passes freely through the hearth plate, the portion which projects. above
the plate receiving a screw cap, which is brought to bear on the hearth
plate by a nut on the leg, in other words, the plate is firmly confined
between the nut and screw cap, and the leg thereby rigidly secured to
the plate.
The air reservoir forming the termination of a fan blower is secured
to the under side of the front portion of the hearth plate, and into the
mouth of this reservoir fits a tuyere plate having any desired number of
holes opening into the hearth.
The fan may be secured to the stand, frame, or hearth plate in any
suitable manner, and may be driven by a system of belts or by any
other equivalent appliance.
In the arrangement described the portable furnace may be used as a
blacksmith's fire, but when it is required for refining metals or for other
purposes where a large concentrated mass of fuel is necessary, the tuyere
plate is removed, and on the hearth immediately above the air reservoir
is placed a vessel having a cover with a central discharge tube, there
being within the vessel a grate for supporting the fuel, which owing to

page_text: the steady blast beneath the grate soon becomes highly heated and in a
proper condition to be used for melting or refining metals, and for
various purposes where an open hearth would not be available. The
products of combustion from this vessel pass off through the central
discharge tube and are directed by the hood of the forge to the chimney
pipe. By raising a small door in the cover of the vessel the condition of
the fuel and the objects acted on by the same can be observed from time
to time.
It has been a common practice to make portable furnaces with
supports cither of heavy cast iron, or of equally cumbrous sheet iron, in
the form of a hollow cylinder; the frames or supports in either case
detracting from the portability of the furnace.
The frame or stand of wrought-iron tubes is not only economical in
point of construction but is remarkably light, and at the same time
more capable of withstanding the shocks necessarily received during
transportation than the heavier cast-iron frames.
In the second part of the Invention, relating to the forges for use on
board vessels or for army purposes, the body of the forge consists of a
sheet-iron box, to each side of which is hinged a door, these doors being
turned down when the forge is in use, thereby exposing openings or
recesses for ready access to the fuel, each door being furnished with turn
buckles or other suitable fastenings by which it can be secured when in
a vertical position, and forms a continuation of the side of the box.
Legs made of angle iron are so fitted to sockets at the corners of the
box that they can be readily detached, and at the rear of the box is
hinged a plate which, when elevated, forms a screen or guard for pro-
tecting the blowing machinery from the sparks, &c., and when depressed
forms the cover of the box, to which it can be secured by suitable bolts,
latches, or other locking apparatus.
Into a dovetailed recess at the rear end of the box is fitted a frame
carrying a fan blower and a driving shaft on which is a grooved wheel,
and from the latter a countershaft is driven by a band, and from this
countershaft is driven the fan spindle. The frame, fan, and driving
appliances are all so arranged that they can be readily detached from the
box in one mass and can be at once placed within the box. When
arranged for use the driving mechanism is steadied by a leg which can
also be detached.

page_text: The fan is secured to the frame in a horizontal position and is driven
by a system of spur or bevil gearing worked by hand or otherwise.
The fuel in the pan is maintained at a proper heating by operating
the fan, and the rivets are placed on the fuel and are withdrawn from
time to time through any one of the three openings presented in raising
any of the lids before mentioned.
The fan blower, forming the fourth part of the Invention, and
applicable to any of the above described forges as well as to other
purposes, consists in forming the circular casing of the fan in two parts
bolted together, and the spindle of the fan turns in bearings attached to
or forming part of the casing, which has central openings for the
admission of air.
In the present instance the fan has but two blades cast in one piece
with its arms and central hub. The blades are so shaped that they
revolve as close as possible to the sides and inner circumference of the
casing without being in absoluto contact therewith.
The inner edge of cach blade has a segmental continuation, concentric
with and overlapping as it were the fan shaft and it is this segmental
continuation which forms the special feature of this part of the In-
vention, for it has been found to add very materially to the efficiency of
the fan as regards the creation of a steady and forcible blast at a
comparatively small expense of power.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 7th November 1874.
TO ALL TO WHOM. THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn. Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of May, in the year of
our Lord One thousand cight hundred and seventy-four, in the 37th
year of Her reign, did, for Herself, Her heirs and successors, give and

page_text: grant unto me, the said John Henry Johnson, Her special license that I,
the said John Henry Johnson, my executors, administrators, and assigns,
or such others as I, the said John Henry Johnson, my executors, admi-
nistrators, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PORTABLE
FORGES OR FURNACES, AND BLOWING APPARATUS," a communication to me
from abroad by De Witt Clinton Baxter, of Philadelphia, Pennsylvania,
United States of America, upon the condition (amongst others) that I,
the said John Henry Johnson, my executors or administrators, by an
instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent..
NOW KNOW. YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:-
The first part of the Invention relates to the peculiar construction of
portable forges described thereafter with the view to the attainment of
simplicity, lightness, durability, and stability.
The second part of the Invention relates to the construction of portable
forges for use on board vessels, or for army uses and other purposes, the
main feature of the Invention being the packing of the whole forge,
including legs and blowing appliances, in a box, which forms part of the
forge, and which can be easily transported.
The third part of the Invention relates to the peculiar construction of
a forge for heating rivets in boiler shops, iron shipbuilding yards, &c.
The fourth and last part of the Invention relates to an improvement,
fully described hereafter, in fan blowers made with the view of increasing
their efficiency and of obtaining an uniform blast.

page_text: And in order that the said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose.
shall refer to the several Figures on the annexed Sheet of Drawings, the
the same letters of reference indicating corresponding parts in all the
Figures..
Figure 1 is a side view of the improved portable furnace referred to in
the first part of the Invention; Figure 2, a front view of the same;
Figure 3 is a plan of the same; Figure 4, a vertical section of part of
the furnace.
Figure 5, a perspective view of the stand or frame.
Figures 6 and 7, views drawn to an enlarged scale, and illustrating the
detailed construction of the stand.
And Figures 8 and 9, views illustrating, the furnace as arranged for
refining and other purposes.
A is the hearth of the furnace, which it is preferred to make of cast
iron, and to which are secured the upper ends of four legs B, B, B, B,
made of wrought-iron tubes, which are connected together in the manner
best observed in Figure 6, where a is a socket adapted to the sides of the
leg. B, and arranged to receive the end of a light wrought-iron tube, the.
opposite end of the latter fitting into a similar socket adapted to the
opposite leg. A bolt E passes through the tube D, and through both of
the legs, and serves to secure the whole firmly together.
=
The method of securing the legs B to the hearth is illustrated in-
Figure 7. The upper threaded end of the leg B passes freely through the
hearth plate A, the portion which projects above the plate receiving a
screw cap b, which is brought to bear on the hearth plate A by a nut d-
on the leg. In other words the plate A is firmly confined between the
said nut and screw cap, and the leg. thereby rigidly secured to the
plate A.
The air reservoir F, forming the termination of a fan blower G, is
secured to the under side of the hearth plate A, and into the mouth of
this reservoir fits a tuyere plate e having any desired number of holes.
:
The fan G may be secured to the stand, frame, or hearth plate A in
any suitable manner, and may be driven by a system of belts illustrated
in Figures 1 and 3, or by any other equivalent appliance.
:

page_text: When arranged, as shown in Figure 4, the portable furnace may be
used as a blacksmith's fire, but when it is required for refining metals or
for other purposes where a large concentrated mass of fuel is necessary,
the tuyere plate e is removed, and on the hearth A, immediately above the
air reservoir F, is placed a vessel H having a cover I with a central
discharge tube i, and within the vessel H is a gratef for supporting the
fuel, which owing to the steady blast beneath soon becomes highly.
heated and in a proper condition to be used for melting or refining.
metals, and for various purposes where an open hearth, as in Figure 4,
would not be available. The products of combustion from the vessel H
pass off through the central tube i, and are directed by the hood 'to the
chimney pipe m. By raising a small door in the cover I of the vessel
the condition of the fuel and the objects acted on by the same can be
observed from time to time.
It has been a common practice to make portable furnaces with supports
either of heavy cast iron or of equally cumbrous sheet iron in the form
of a hollow cylinder, the frames or supports in either caso detracting
from the portability of the furnace.
The frame or stand of wrought-iron tubes is not only economical in
point of construction, but is remarkably light, and at the same time
more capable of withstanding the shocks necessarily received during
transportation than the heavier cast-iron frames.
The second part of the Invention relating to forges for use on board
vessels, or for army purposes, is illustrated in the perspective view.
Figure 10 shows the forge arranged for use; Figure 11, the forge as a
folded for storage or transportation; and Figure 12 shows an enlarged
view of the hearth plate. The body of this forge consists of a sheet-iron
box A, to each side of which is hinged a door a, these doors being turned
down, as shown in Figure 10, when the forge is in use, thereby exposing
openings or recesses 6 for ready access to the fuel. Each door a is fur- a
nished with turn buckles d or other suitable fastenings, by which it can.
be secured when in a vertical position, and so form a continuation of the
side of the box. Legs B made of angle iron are so fitted to sockets e at
the corners of the box that they can be readily detached, and at the rear of
the box is hinged a plate D, which when elevated, as shown in Figure 10, 3
forms a screen or guard for protecting the blowing machinery from the
sparks, &c., and when depressed forms the cover of the box, to which it
can be secured by suitable bolts, latches, or other, locking apparatus..

page_text: Into a dovetailed recess at the rear end of the box is fitted a frame E
carrying a fan blower G and a driving shaft, on which is a grooved
wheel F, and from the latter a countershaft is driven by a band, and
from this countershaft is driven the fan spindle. The frame E, fan-G,
and driving appliances are all so arranged that they can be readily
detached from the box in one mass, and at once placed within the box.
When arranged for use, as shewn in Figure 10, the driving mechanism
is steadied by a leg H, which can also be detached.
The hearth plate I, shewn in the enlarged view, Figure 12, is secured
to the bottom of the box, and in the centre of this hearth plate is a
tuyere plate m having any desired number of openings; and below this
plate is the air reservoir n, communicating through a pipe q with the fan
blower.
The air reservoir n is made to fit snugly in V shaped guides on the
under side of the hearth plate so as to be readily detached therefrom,
the pipe q being also detacliable from both the air reservoir n and the
fan G.
The box is so proportioned to the above mentioned parts that the
whole, including the frame E, fan G, and driving mechanism legs B, air
reservoir n, pipes q, and steadying leg H, can be snugly packed away
within it, the said box being provided with eyes by which it can be
suspended to deck beams when required.
It will be observed that the tuyere plate m is somewhat less than the
recess in which it fits, so that it can expand and contract independently
of the hearth plate, which is thus protected from the injurious effects of
the expansion of the tuyere plate.
The rivet heating forge, which forms the third part of the Invention,
is illustrated by Figures 13 and 14. A frame A of cast iron is supported
on four tubular legs B of wrought iron, the legs being connected together
and to the frame in the manner described in referring to the first part of
the Invention. The two front legs are however in the present instance
attached to an axle a provided with wheels b, b, so that by grasping
handles d, d, attached to the frame, and slightly tilting the latter, the
entire forge can be readily wheeled from place to place.
To the frame A is secured the pan D, to the upper edge of which is
hinged a lid E, and to the latter are hinged three lids F, on elevating

page_text: any one of which a pair of tongs can be introduced into the pan for
seizing and withdrawing the rivets.
A grated basket or fuel holder G is suspended within the pan D, and
air from a fan H is forced into the space between the pan D and grated
basket G through a pipe b and air reservoir d, above which and in the
bottom of the basket G is a grate ½, best observed in the perspective
view, Figure 14, and prongs of a rake M projecting through the bars of
the grate, so that on agitating the said rake the ashes will be withdrawn
from the available fuel, and will fall into the air reservoir d, whence
they can be withdrawn from time to time by opening a sliding gate n.
The fan H is secured to the frame A in a horizontal position and is
driven by a system of gearing too clearly illustrated in the Drawing to
need description.
The fuel in the pan D is maintained at a proper heat by operating the
fan H, and the rivets are placed on the fuel, and are withdrawn from
time to time through any one of the three openings presented in raising
any of the lids E.
The fan blower forming the fourth part of the Invention, and applicable
to any of the above described forges, as well as to other purposes, is
illustrated in the vertical section, Figure 15, transverse section, Figure 16,
and perspective view, Figure 17. The circular casing A of the fan is
made in two parts, bolted together as shown in Figure 16, and the
spindle B turns in bearings a, a, attached to or forming part of the
casing A, which has central openings b, b, for the admission of air.
-
In the present instance the fan has but two blades D, D', cast in one
piece, with the arms d, d, and central hub e. The blades D, D₁, are so
shaped that they revolve as close as possible to the sides and inner
circumference of the casing without being in absolute contact therewith.
The inner edge of each blade D, D¹, has a segmental continuation m
concentric with the shaft B, and it is this segmental continuation which
forms the special feature of this part of the Invention, for it has been
found to add very materially to the efficiency of the fan as regards the
creation of a steady and forcible blast at a comparatively small. expense
of power.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or

page_text: :
carried into effect, I would observe in conclusion that what I consider to
be novel and original and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is, -
First. The combination of a fan blower with a portable forge, substan-
tially as herein-before described and illustrated by the Figures 1, 2, 3, 4,
and 5 of the accompanying Drawings.
Second. In a portable- forge the combination of a hearth plato with
wrought-iron tubular legs connected to each other and to the said hearth
plate, substantially as and for the purpose herein-before described and
illustrated by Figures 1, 2, 3, 4, 5, 6, 7, and 8 of the accompanying
Drawings.
Third. The arrangement and use of a portable forge consisting of a
box A, constructed and of sufficient capacity to contain the detachable
legs, fan blower, and other appliances, substantially as herein-before
described and illustrated by Figures 10, 11, 12 of the accompanying
Drawings.
Fourth. The construction and arrangement of the box A, having
doors a, a, for exposing or closing openings 6 in the opposite sides of
the box, substantially as and for the purpose herein-before described and
illustrated by Figures 10 and 11 of the accompanying Drawings.
Fifth. The construction and arrangement of the box A, having a
hinged plate D serving as a lid to the box, or as a screen for the fire,
substantially as herein-before described and illustrated by Figure 10 of
the accompanying Drawings.
Sixth. The arrangement and use of the tuyere plate m so adapted to
the hearth plate that it can expand and contract laterally independently
of the said hearth plate, substantially as herein-before described and
illustrated by Figure 12 of the accompanying Drawings.
Seventh. The construction and use of a portable rivet forge having a
pan D with openings and lid and a basket G for containing the fuel,
substantially as and for the purpose herein-before described and illus.
trated by Figure 13 of the accompanying Drawings.
Eighth. The combination of the said pan D, fuel basket G, and air
reservoir d, substantially as and for the purpose herein-before described
and illustrated by Figure 13 of the accompanying Drawings.

page_text: Ninth. The combination of the grated tuyere h with the rake M, sub-
stantially as and for the purpose herein-before described and illustrated
by Figures 13 and 14 of the accompanying Drawings..
Tenth. The construction and use of the fan blower with its vanes and
segmental continuations of the same, substantially as and for the purpose
herein-before described and illustrated by Figures 15, 16, and 17 of the
accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Sixth day of
November One thousand eight hundred and seventy-four.
T TENDY TOWNSON.