IMPROVEMENTS IN THE MANUFACTURE OF STEEL DISC WHEELS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Edmund Edwards at the Office of the
Commissioners of Patents on the 27th September 1883. Communicated to
him from abroad by La Compagnie anonyme des Forges de Châtillon et
Commentry in the Republic of France
EDMUND EDWARDS, of the firm of Edwards and Co :-, Patent Agents and
Engineers, of 35, Southampton Buildings, Chancery Lane, in the County of
Middlesex "IMPROVEMENTS IN THE MANUFACTURE OF STEEL DISC WHEELS"
[communicated to him from abroad by La Compagnie anonyme des Forges de
Châtillon et Commentry in the Republic of France]
The centres of disc wheels, for railway and other purposes, have ordinarily
heretofore been made either of wrought iron, or of plain cast steel.
Both these methods are however objectionable, for wrought iron centres are
wanting in homogeneity and are liable to crack at the welds, whilst cast steel
though free froin these defects is hard and brittle and whilst possessing considerable
resistance to fracture, is almost incapable of extension.
The present invention has for its object a method of making such wheel centres
of cast steel submitted to a series of operations tending to impart to it all the
qualities of wrought steel, so that instead of a hard and brittle metal it becomes of
high resistance and capable of bending without fracture.
These operations consist of a novel method of compressing the metal by
sufficiently powerful pressure, then tempering it in oil and annealing it.
Steel wheel centres manufactured in this way possess, in regard to the
requirements of Railways, all the properties of iron centres, resisting as well as or
better than the latter the tests of blows or of punching the boss, and having
however the advantage of being made of a single piece of cast metal homogeneous
throughout, instead of a number of pieces welded together, in which there is
always risk of failure at the weld.
In order to put the invention in operation, melted steel is run into a mould of
suitable sand so as to form a wheel centre of the desired shape, and having extra
thickness where necessary to allow for the subsequent compression.
On removal from the mould it is submitted to an annealing process to prevent
breakage in shrinking.

page_text: The centre is then submitted to pressure between dies of the ordinary well
known kind in order to give it its final definite shape. This may be effected at a
single operation by making use of a pair of dies covering the whole surface of the
wheel centre; or if a greater pressure per square inch of surface is desired, the
compression may be effected by a series of operations acting in succession over only
a part of the surface. For instance, the first pair of dies would include only the
central boss of the wheel and a part of tho disc round it, these two surfaces
together forming half the entire surface of the wheel. A second pair of dies is
then substituted, which give its proper shape to the remainder of the wheel. By
this second operation the parts which were left outside the first pair of dies are
also in turn compressed, and its proper form is given to the entire wheel.
Instead of two compressing operations only as described, any larger number may
be used, each affecting as small a part of the wheel centre as may be desired, and
in this way the same pressure of the dies will effect a greater compression in
proportion as the surface operated upon is less.
The wheel centre is finally finished between a pair of dies embracing its whole
surface.
The centre cast and compressed as described is then tempered in oil, and is
carefully annealed, the heat at which tempering and annealing are effected being
dependent upon the degree of hardness of the metal.