IMPROVEMENTS IN THE MANUFACTURE OF CRANK AXLES.
Year: 1859

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New Cannon.
Street, in the City of London, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF CRANK AXLES.
Sealed the 8th September 1859, and dated the 16th March 1859.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the
16th March 1859.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in the
City of London, do hereby declare the nature of the Invention for "Im-
PROVEMENTS IN THE MANUFACTURE OF CRANK AXLES," to be as follows:-
My Invention consists partly in the manufacture of locomotive engine and
other crank axles from a slab or mass of homogeneous cast malleable iron,
semi-steel, or steel, the general configuration or shaping of such mass into a
crank axle being effected by sawing or cutting away such parts of the slab or
mass as are not required to form part of it. The superfluous parts having
been removed from the slab may be forged or rolled into plates, bars, or other
useful forms. In carrying out this part of my Invention I prefer to use
malleable irou, semi-steel, or steel obtained in a fluid state direct from crude
iron, although malleable iron or steel otherwise obtained may be employed.
I pour or run the fluid metal into an iron or other suitable mould, so as to
obtain an ingot or mass by preference of a square or rectangular form. I then
forge or roll such ingot until a flat slab is produced, of such dimensions that
the intended crank axle may be obtained therefrom by cutting away the
superfluous metal. This I prefer to effect by a circular saw, or by a series of
vertical or circular saws, mounted in a suitable frame, provided with slides
or with a carriage, on which the flattened rectangular mass of forged metal

page_text: is placed, and by means of which it may be advanced up to the saws, or the
saws to it, as required. I prefer that the saws should travel at a rapid rate,
as at present practised with the sawing apparatus employed in cutting off the
ends of railway bars. This cutting away of the superfluous metal from the
slab is effected while the latter is in a heated state, the saws running through
or in contact with water so as to keep them cool, but as the saws will not
remove the metal from between the crank throws, I either cut this part down
by a wide cold chissel (in a suitable press or under the hammer), or I remove
the piece by drilling after the mass has cooled.
In some cases I employ a slotting machine for cutting away the superfluous
metal from the flat hammered slab, the slotting machine having several, and
by preference as many slotting tools in operation at a time as there are grooveš
or cuts to be made in the slab, so that when it is once placed in the machine
it will be quickly operated upon, the slides of the machine being so arranged
as to admit of the necessary variations of size for crank axles of different
forms and dimensions. When an axle with more than one crank is required,
I form the throws or cranks in the same plane with each other, and when the
superfluous parts of the mass have been cut away, I place the rudely formed
crank axle on a strong iron frame, to which I securely fasten one portion of
it while another portion of it is fastened to a moveable part of the frame, the
axis of which moveable part is coincident with the axis of the crank axle;
motion is then communicated by suitable gearing or apparatus to this
moveable part, whereby the crank axle is twisted until each throw or crank
formed therein is made to assume the desired position, the heat at which
this twisting of the axle is effected being such as is found most suitable for
the peculiar quality of the metal of which it is composed; after this process
the angles may be hammered, cut off, and finished in the usual way.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Bessemer in the Great Seal Patent Office on the
16th September 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, in the City of London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of March, in the year of our Lord One
thousand eight hundred and fifty-nine, in the twenty-second year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Henry Bessemer, Her special licence that I, the said Henry Bessemer, my
executors, administrators, and assigns, or such others as I, the said Henry
Bessemer, my executors, administrators, and 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 THE MANU-
PACTURE OF CRANK AXLES," upon the condition (amongst others) that I, the
said Henry Bessemer, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should parti-
cularly 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 Henry Bessemer, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
In the manufacture of locomotive and other crank axles by welding
together several bars or slabs of wrought iron, it frequently happens that the
pieces so to be united are not perfectly welded throughout the whole of their
contiguous surfaces, thus forming flaws or cracks which weaken the metal at
those parts where they occur, and greatly augment the liability to fracture
whenever the crank axle is subjected to heavy strains; these defects in welding
are more especially injurious when they occur in those parts of the throw of
the crank which are at right angles to its axis, and when the flaw. also runs.
in this direction, that is, at right angles to the limb of the crank. The
direction in which the grain or fibre of the wrought iron is cut through in.
forming a crank throw from a solid mass or projection on the shaft (by
cutting out the webs after the crank is forged) tends also to weaken those.
parts, and still further to lessen its powers of resistance to heavy strains.
I will now proceed to describe in what manner I manufacture crank axles,
and how I avoid the defects before referred to by the employment of a
material and a mode of manufacture whereby the crank axle may be formed
in one piece without welding, and in which the homogeneous character of the
metal renders each part capable of resisting an equal amount of strain
irrespective of the position it occupies in the mass; this my Invention
Consists partly in the manufacture of locomotive engine and other crank axles

page_text: from a slab or mass of homogeneous cast malleable iron, semi-steel, or steel,
the general configuration or shaping of such mass into. a crank axle being
effected by sawing or cutting away such parts of the slab or mass as are not
required to form part of it. The superfluous parts having been removed from
the slab may be forged or rolled into plates, bars, or other useful forms. In
carrying out this part of my Invention I prefer to use malleable iron, semi-
steel, or steel obtained in a fluid state direct from crude iron, although
malleable iron or steel otherwise obtained may be employed. I pour or
run the fluid metal into an iron or other suitable mould, so as to obtain an
ingot or mass by preference of a square or rectangular form. I then forge
or roll such ingot until a flat slab is produced of such dimensions that the
intended crank axle may be obtained therefrom by cutting away the super-
fluous metal. This I prefer to effect by a circular saw or by a series of
vertical or circular saws mounted in a suitable frame provided with slides, or
with a carriage on which the flattened rectangular mass of forged metal is
placed, and by means of which it may be advanced up to the saws, or
the saws to it, as required. I prefer that the saws should travel at a
rapid rate, as at present practised with the sawing apparatus employed in
cutting off the ends of railway bars. This cutting away of the superfluous
metal from the slab is effected while the latter is in a heated state,
the saws running through or in contact with water so as to keep them cool,
but as the saws will not remove the metal from between the crank throws, I
either cut this part down by a wide cold chisel (in a suitable press or under
the hammer,) or I remove the piece by drilling after the mass has cooled.
On the Sheet of Drawings hereunto annexed, I have shewn in perspective,
at Figure 1, a flat slab of cast steel, semi-steel, or cast malleable iron, which
has been rolled or hammered from an ingot into the simple rectangular form
there represented. The slab may, if preferred, be formed with flattened
angles, as shewn at Figure 2, or it may be rounded at each edge, as shewn in
Figure 3; in either case the thickness should be uniform throughout, and
equal to the greatest thickness or diameter of any part of the crank axle. In
order to form from such plain flat slabs a double-throw crank axle suitable
for a locomotive engine, I make in it several incisions, as shown in Figure 4,
and marked respectively a, b, c, d, and e. These incisions being made per-
pendicular to the surface of the slab, and at right angles to its edges, will
form at once, and with considerable accuracy, the chief bounding lines of each
throw of the crank, the cuts c, c, and e, e, forming the spaces between the
throws and the cuts b, b, and d, d, determining the thickness of the metal left
in each throw; if, then, two other incisions a, a, be made, the rectangular

page_text: pieces ff, will be separated from the general mass, and may afterwards be
hammered or rolled into plates or bars, or may be otherwise utilized. If,
also, an incision be made by a large flat chisel or cutter while the mass is in
a heated state, or if a series of holes be drilled as close together as possible
along the dotted lines 9, 9, after the mass has cooled, the pieces h, h, may be.
removed from between the crank throws in a similar manner. The piece i
may also be removed by cutting or drilling on the dotted line ;; each of the
pieces h, h, and i, i, may also be utilized as before described, in reference to
the pieces ff; the general configuration and proportions of the intended
crank axle will thus be obtained, as shown at Figure 5. The sharp angles of
the rudely formed crank may then be sawn or cut off while hot, or be worked
down by the hammer, or they may be removed by the planing machine or
lathe after the metal has cooled down, as may be found desirable. In some
cases, where the axis of the crank is long, it will be found desirable to leave
the end pieces n, n, wider than is shown in Figure 4, by making the incisions
on or near the dotted lines 1, 7; those parts of the axle marked n, n, may then.
be forged down to the required diameter, and will thus be elongated beyond
the length of the original slab from which it was formed. The. extent to
which this elongation is effected may be varied by varying the position of the
incisions r, 1.
In lieu of removing the superfluous metal from the flat slab
by means of the saw, I in some cases employ a slotting machine for cutting
away the superfluous metal from the flat hammered slab, the slotting machine.
having several, and by preference as many slotting tools in operation at a time;
as there are grooves or cuts to be made in the slab, so that when it is once.
placed in the machine, it will be quickly operated upon, the slides of the
machine, being so arranged as to admit of the necessary variations of size for
crank axles of different forms and dimensions.
When aņ axle with more than one crank is required, I form the throws or
cranks in the same plane with each other, and when the superfluous parts of
the mass have been cut away, I place the rudely formed crank axle on a
strong iron frame, to which I securely fasten one portion of it, while another
portion of it is fastened to a moveable part of the frame, the axis of which
moveable part is coincident with the axis of the crank axle. Motion is then
communicated by suitable gearing or apparatus to this moveable part, whereby
the crank axle is twisted until each throw or crank formed thereon is made to
assume the desired position, the heat at which this twisting of the axle is
effected being such as is found most suitable for the peculiar quality of the
metal of which it is composed; after this process the angles may be hammered,
cut off, and finished in the usual way.

page_text: The twisting of the axle so as to cause the different throws formed thereon
to assume any desired angle with reference to each other, may be effected in
cranks of small size by twisting them by hand, or when one of the throws is
held beneath a heavy steam hammer with the whole weight of the hammer
resting on it, the other throw may be forced round with a lever. until they
assume the desired relative position, the twisting of the metal taking place
between the points marked m, m, Figure 5; but when the size of the crank
axle is such as to prevent its being twisted in this manner, then any suitable
apparatus may be employed for twisting it, as will be readily understood by
engineers and others engaged in the manufacture of crank axles, and to the
construction and arrangement of which I lay no claim. I am aware that
it has been proposed to make crank axles from a slab of welded wrought
iron; I therefore make no claim thereto, but what I do claim as of my
Invention, is,
Firstly, the manufacture of locomotive and other crank axles from a plain
slab or rolled or hammered ingot of cast malleable iron, cast steel, or cast
semi-steel, by sawing or otherwise cutting away such parts of the mass as
will leave a piece of metal having the general form or configuration of the
intended crank axle.
Secondly, I claim the use or employment of circular or other saws for
shaping a mass, or for cutting away the superfluous portions from a mass of
cast malleable iron, cast steel, or cast semi-steel while the same is in a heated
state, in order to obtain from the mass of metal so cut or shaped a locomotive
or other crank axle.
Thirdly, I claim, in the manufacture of locomotive.and other crank axles 2
made of cast malleable iron, or cast steel, or cast semi-steel, the twisting of
the axle so as to alter the angle of the different throws from the common
plane in which they are formed into any desired angle or relative position to
each other.
In witness whereof, I, the said Henry Bessemer, have hereunto set my 3
hand and seal, this Fourteenth day of September, in the year of our
Lord One thousand eight hundred and fifty-nine.
HENRY BESSEMER. (L.S.)