IMPROVE- MENTS IN RAILWAY AND OTHER WHEELS AND WHEEL TYRES
Year: 1858

page_text: PROVISIONAL SPECIFICATION left by Henry Bessemer at the Office of
the Commissioners of Patents, with his Petition, on the 1st December
1858.
I, HENRY BESSEMER, of 4, Queen Street Place, New Cannon Street, in the
City of London, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN RAILWAY AND OTHER WHEELS AND WHEEL TYRES," to be as follows:-
My Invention consists, firstly, in the employment or combination in one
wheel or tyre of two or more kinds of iron or of two or more qualities of steel,
or the employment or combination of iron and steel of any desired kind or
quality, in the formation of a wheel or wheel tyre by the process of founding;
and, secondly, in the employment or combination of molten iron of any desired
kind, or of molten steel of any suitable quality, or of iron and steel with other
iron or steel in a heated and wrought' or unwrought state in the manufacture
of founding wheels and tyres by centrifugal apparatus.
For the purposes of this Invention I construct a mould of malleable iron,
steel, or cast iron, alone or combined, and in some cases I line the interior or
I make some parts of said mould with loam, clay, sand, plumbago, or any
combination thereof, or with other suitable refractory slow conductors of heat,
such parts of the mould as may be necessary being made to slide or yield to
pressure in order freely to allow the cast wheel or tyre to shrink without being
cracked or injured.. The mould is mounted on a vertical, horizontal, or
inclined axis, whereby I am enabled to communicate a rapid rotatory motion
thereto, and cause the fluid metal at the time of casting to be powerfully acted

page_text: upon by centrifugal force. The metal may be poured or run into the mould
quickly so as to form a fluid mass, possessing when solidified the ordinary
character of cast iron or steel, or the metal may be poured in slowly, and thus
accumulate in the mould in small successive portions, which unite, solidify,
and gradually build up the casting in their successive layers; the solidifying
surface being protected and cooled, if desired, by the employment of water or
any other suitable fluid or gaseous matter. The metal intended to form the
outer or rolling surface of the wheel or tyre is first run or poured into
the mould, and when solidified, or nearly so, is to be speedily followed
by the other kind or quality of fluid metal, so that the two may be united
by the fluid metal adhering to and uniting itself with the heated solidified
mass first run into the mould, and whereby the two kinds of metal will
have a distinct line of junction although firmly united to each other; or
the workman may commence to pour into the mould the second portion
of metal before the pouring in of the first kind has ceased, whereby an union
of a portion of the two fluids will take place, and the two qualities or kinds
of metal will thus unite and blend together, so that the transition from one
kind or quality of metal to the other will be gradual and almost imperceptible.
The metals employed in this process are grey, mottled, white and refined pig
iron, hard, medium, and soft steel, and molten malleable iron, or any alloy of
iron or steel with other metals at present known or used, provided that iron
forms at least 90 per eent. of any such alloy. The wheels when made of
malleable metal on their exterior or rolling surface may be hammered, and
if made of steel externally, may be hardened in the ordinary way by heating
and quenching. The tyres when made of malleable metal may, if desired, be
hammered, rolled, and increased in size to any desired extent, and may also
in like manner be hardened and tempered. When tyre rings, spokes, arins,
or discs of solid iron or steel in a wrought or unwrought state are to be
combined with or form part of a complete wheel or tyre by casting thereon or
attaching thereto other parts formed of fluid iron or steel by means of cen-
trifugal casting apparatus, I first cleanse the surfaces of such solid iron or steel,
and highly heat the same before inserting them into the centrifugal mould,
and in some cases I make holes or grooves, or I so undercut the solid metal as
will effectually prevent the separation of the newly cast parts from the other
portion of the wheel or tyre. It will thus be seen that in the making of
wheels and tyres several distinct combinations may be formed with the
different metals or alloys before described, and whereby the hardness and
durability of one part, and the necessary cohesion and strength of others,
may be obtained in the same wheel or tyre to a greater extent than would

page_text: result from the use of any one quality of metal if used alone; thus the exterior
or rolling surface of a wheel or tyre may be made either of chilled, grey,
mottled, white or refined pig iron, having an inner ring, disc, or arms and boss
formed of hard, medium, or soft steel or of malleable iron; or the same qualities
of iron may be employed for the outer or rolling surface without being chilled,
by using a slow conductor of heat as a lining to that part of the mould against
which the exterior of the tyre is formed, and so in like manner hard, medium,
or soft steel or malleable iron may be used to form the rolling surface of any
wheel or tyre, while the ring, arms, disc, boss, or other parts are made of a
different quality of steel to that used for the rolling surface, or they may be
formed of any of the qualities of iron before enumerated, or in such manner
that the wheel or tyre is composed of two or more qualities or kinds of iron or
steel or alloys thereof united together in the act of casting in centrifugal or
revolving moulds.