IMPROVEMENTS IN THE MANUFACTURE OF RAILWAY CARRIAGE WHEELS, APPLICABLE ALSO TO THE MANUFACTURE OF OTHER ANALOGOUS ARTICLES
Year: 1869

page_text: LETTERS PATENT to Nathan Washburn, of Massachusetts, of the
United States of America, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF RAILWAY CARRIAGE WHEELS, APPLICABLE ALSO TO THE
MANUFACTURE OF OTHER ANALOGOUS ARTICLES."-A communication from
Zadock Washburn, of Massachusetts.
Sealed the 17th December 1869, and dated the 14th October 1869.
COMPLETE SPECIFICATION filed by the said Nathan Washburn at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 14th October 1869, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL PERSONS TO WHOM THESE PRESENTS MAY COME, BE
IT KNOWN, that I, NATHAN WASHBURN, of Massachusetts, of the
United States of America, am in possession of a new and useful
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF RAILWAY CARRIAGE
WHEELS, APPLICABLE ALSO TO THE MANUFACTURE OF OTHER ANALOGOUS ARTICLES,"
such Invention was communicated to me by one Zadock Washburn, of
said Massachusetts, and I do hereby declare the nature of the Invention

page_text: and the manner in which it is to be performed, to be fully set forth
in the following Specification, reference being had to the accompanying
Drawings, exhibiting a side view of one of the said wheels.
The purpose
of my
mode of making the wheel is to compose the rim
of cast iron, and an annular tire or reinforce of either wrought iron or
steel, and to form a union of the two at their surfaces in contact.
accomplish this in manner which I will now proceed to describe.
I
In the accompanying Drawing the wheel rim a, spokes b, and the
hub c are to be supposed to be of cast iron, and the reinforce or
circumscribing tire d to be either of wrought iron or steel.
In carrying out my process of making this wheel, which is also
applicable to the manufacture of many analagous articles, that is,
articles which have a body of cast iron and a circumscribing reinforce
of wrought iron or steel, I proceed as follows:-I first heat the reinforce
up to a temperature which will enable me to render fluid and run upon
its inner surface a flux or composition consisting of one part (by
weight) of sal ammoniac to fifteen parts (by weight) of borax. After
having applied the composition to the surface, I next heat the reinforce
or tire up to a welding temperature, after which I place it within the
mould or matrix to be used in casting or giving form to the cast-iron
portion of the wheel. Immediately afterwards I run into the mould
the iron in a molten state until the mould may have been properly
filled by it. The reinforce will at once be very much increased in
temperature by the cast metal, so much so, that where the two may be
in contact the reinforce will be fused by and so as to weld firmly to the
cast metal.
As the tire or reinforce will expand more than the cast iron, it will
be found that during the process of cooling of the two the contraction
of the former will be a little greater than that of the latter, so that it
will be impossible for the cast iron to draw away and separate from the
reinforce during the process of cooling of the two. Thus the two will
be firmly welded together.
By my process I overcome by the greater power of shrinkage of the
reinforce of wrought iron or steel the tendency of the cast metal body
while contracting to draw away and separate from the reinforce; and
were I not first to expand the reinforce to a welding heat, or to as high
a temperature as I could well get it without its melting, and while at
such a temperature cast the iron against it, I could not in most cases

page_text: produce the effect or prevent the cast iron and the reinforce from cooling
without a rupture of one or the other, or a separation of one from the other.
Nor could I prevent the steel from being injured by the cast metal.
I am aware that a cast-iron wheel after having been made and
cooled has had a steel or wrought-iron tire placed upon it by the process
of heating the tire and shrinking it on the wheel; therefore I make no
claim thereto. Nor do I claim the common and well known process of
welding a piece of wrought iron or a piece of steel to cast iron by
moulding the cast iron upon the stoel or wrought iron, without
previously heating the steel or wrought iron to a welding temperature
and casting the metal against it when so heated.
What I claim as my Invention is, the new or improved process,
substantially as described, of uniting an annular tire or reinforce to a
wheel or body of cast iron.
I also claim the improved manufacture, as described, consisting of a
cast-iron wheel or body thereof, and a wrought-iron or steel tire or
reinforce combined or welded together by the process of heating the
reinforce, and applying to it a welding composition, and subsequently
raising it to a welding temperature, and finally casting against its
inner surface the cast-iron body, as specefied.
In witness whereof, I, the said Nathan Washburn, have hereunto
set my hand and seal, this 28th day of September 1869.
NATHAN WASHBURN. (L.S.)