IMPROVEMENTS IN WHEELS FOR RAILWAY CARRIAGES, AND IN THE MODE OR MODES OF MANUSACTURING THE SAME
Year: 1852

page_text: LETTERS PATENT to William Walker, of Liverpool, in the County
of Lancaster, Patent Agent, for the Invention of "IMPROVEMENTS
IN WHEELS FOR RAILWAY CARRIAGES, AND IN THE MODE OR MODES
OF MANUSACTURING THE SAME "A communication.
An
PROVISIONAL SPECIFICATION left by the said William Walker.
at the Office of the Commissioners of Patents, with. his Petition,
on the 1st October 1852.
I, WILLIAM WALKER, of Liverpool, in the County of Lancaster,
Patent Agent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN WHEELS FOR RAILWAY CARRIAGES, AND IN THE MODE OR
MODES OF MANUFACTURING THE SAME," to be as follows:-
This Invention consist in casting the wheels with the rim, arms, and
enlarged portion surrounding the hub (or nave) hollow, and of a
curved form, the metal being of a uniform thickness, excepting in the
hub (or nave), tread, and flange. The immediate object of this con-
struction is to allow the various parts to yield and accommodate them-
selves to each other during the process of shrinkage in cooling, and
thus avoid the danger of cracking in case certain portions of the wheel
become fixed and cooled before others. This wheel, as well from the
curved and hollow form of its several parts, which of itself insures

page_text: strength, as from the fact that the uniformity of crystallization
cooling leaves no portion of the metal in a higher state of tension than
another, is admirably suited to resist without injury to itself from the
straining, racking, and twisting to which railway carriage wheels ar
cubicotad
SPECIFICATION in pursuance of the conditions of the Letters Paten
filed by the said William Walker in the Great Seal Patent
Office, on the 1st April 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM WALKER, of Liverpool, in the County of Lancaster, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of October, A.D. One thou-
sand eight hundred and fifty-two, in the sixteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said William Walker, Her special licence that I, the said William
Walker, my executors, administrators, and assigns, or such others as I,
the said William Walker, 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 King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN WHEELS FOR RAILWAY CAR-
RIAGES, AND IN THE MODE OR MODES OF MANUFACTURING THE SAME," upon
the condition (amongst others) that I, the said William Walker, 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 Oflice within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Walker, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say):

page_text: 66
66
"This Invention consists in casting the wheels with the rim,
"arms, and enlarged portion surrounding the hub (or nave) hollow,
"and of a curved form, the metal being of a uniform thickness,
"excepting in the hub (or nave), tread, and flange. The immediate
object of this construction is to allow the various parts to yield and
"accommodate themselves to each other during the process of shrink-
age in cooling, and thus avoid the danger of cracking in case certain
portions of the wheel become fixed and cooled before others. This
"wheel, as well from the curved and hollow form of its several parts,
"which of itself insures strength, as from the fact that the uniformity
"of crystallization in cooling leaves no portion of the metal in a higher
"state of tension than another, is admirably suited to resist without injury
"to itself from the straining, racking, and twisting to which railway
carriage wheels are subjected."
«
To enable others skilled in the art to make and use this Invention I
will proceed to describe it. Fig. 1, is a perspective view of the im-
proved cast iron wheel. Fig. 2, is the transverse, and Fig, 3, the
longitudinal section of the same. Similar letters in the several Figures
refer to corresponding parts. The wheel is one entire casting; the
thickness of the metal is uniform, excepting in the nave or hub, the
tread, and the flange, where it is increased to insure the requisite
amount of strength in these several parts. A, A, is the rim, which is a
hollow circular cylinder provided on its outward periphery with the
ordinary tread a, and flange d. B, B, are the arms or spokes, likewise
tubes, their outer surfaces being concave give a dish-like appearance to
the wheel; contracted at their middles, and enlarging towards their
extremities, they gradually curve into the rim, and towards the centre
into each other, forming by their trumpet-mouthed construction the
enlarged space surrounding the hub. C, is the nave or hub, also
hollow, and composed of a thicker body of metal than the wheel gene-
ally, in order to enable it to resist the increased strain exerted on this
portion, as also to afford a sufficient bearing surface for the axle, which
s secured in the usual or most approved manner. b, b, are the points
r centres from which the arcs of circles forming the sides of the arms.
re drawn.
From a perusal of the foregoing, and reference to the accompanying

page_text: Drawings, it will readily be perceived that all the parts being curved are
capable of yielding and accommodating themselves to each other during
the process of shrinkage, which takes place in cooling without the danger
of cracking and breaking, to which wheels cast with straight spokes are
liable. Suppose, for instance, a circular rim cast with straight arms;
certain portions will become cool and fixed before others, say the rim
before the arms; the contraction of the arms will either cause some of
them to crack, or leave the metal in such a state of tension as to
endanger their breakage by the shocks to which railway wheels are
constantly liable; whereas in case of the wheel with hollow and curved
parts, as represented in the Drawings, the contraction merely tends to
straighten the arms without injury to the metal. The necessity for
chilling the tread of railway carriage wheels, which process suddenly
contracts the metal in contact with the chills, renders the importance of
this form of wheel obvious. It is, moreover, lighter, and, in consequence
of its form, stronger, than other wheels; all the pressure acting on
curves arranged on the principle of the arch. The words quoted in the
foregoing description of this Invention are those used in the Provisional
Specification. What I claim is, the combination of the curved hollow
arms with the hollow rim made circular in its inner part, and hollow
curved nave or hub enlarged, and forming a continuation of the curves
of the inner ends of the arms for causing all the parts of the wheel to
accommodate themselves to each other in shrinking or cooling, sub-
stantially in the manner and for the purpose herein set forth and
described.
In witness whereof, I, the said William Walker, have hereunto
set my hand and seal, this Thirtieth day of March, A.D.
One thousand eight hundred and fifty-three.
WILLIAM (L.S.) WALKER.
Signed and sealed in the presence, of me,
SAM
HOLME,
Mayor of Liverpool.