IMPROVEMENTS IN THE MANUFACTURE OF WHEELS FOR TRAMWAY AND RAILWAY CARRIAGES AND TRUCKS AND OTHER VEHICLES
Year: 1878

page_text: LETTERS PATENT to Robert Hadfield, of Sheffield, in the County of York, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF WHEELS FOR
TRAMWAY AND RAILWAY CARRIAGES AND TRUCKS AND OTHER VEHICLES."
Sealed the 22nd November 1878, and dated the 24th August 1878.
PROVISIONAL SPECIFICATION left by the said Robert Hadfield at the Office
[f
of the Commissioners of Patents on the 24th August 1878.
ROBERT HADFIELD, of Sheffield, in the County of York. IMPROVEMENTS IN
THE MANUFACTURE OF WHEELS FOR TRAMWAY AND RAILWAY CARRIAGES AND
TRUCKS AND OTHER VEHICLES."
My present Invention relates to improvements in that class of wheels for the
manufacture of which Letters Patent were granted to me on the 20th day of
January 1877, No. 264. Wheels manufactured upon the improved principles
described in the Specification of such Letters Patent have proved excellent wheels,
but are found in practice to be difficult and expensive to cast, while the lighter
wheels are apt to twist and warp, and thus lose the truth of their form.
My present improvements in the manufacture of such wheels consist in casting
a wheel in steel or any other suitable metal, having six or any other convenient
number of straight arins, hereafter called the main arms, springing from the boss
or nave of the wheel, each of which main arms diverges or radiates at its outer end
into two short curved arms or supports, terminating at the rim or tyre of the wheel.
Thus a wheel having six of such straight arms springing from its boss or nave
would have twelve short curved arms or supports joining on to the inner periphery
of its rim or tyre. These curved arms or supports do not increase the weight of
the wheel, as the intermediate spaces between the main arms, as also between
such outer curved arms are left hollow, whereby great lightness is imparted to the
same.
Wheels made in this improved form are easier and simply to cast, and less
expensive than those described in the Specification of my said Letters Patent
No. 264, of 1877; they are also far less liable to lose the truth of their form, and

page_text: are prevented from breaking owing to any internal strain while cooling after being
cast; they are also much more elastic than any hitherto in use, and are thus par-
ticularly well adapted for use for tramway and railway purposes.
Another advantage of this improved form of wheel is that the actual use of all
the steel in the tread of the wheel is obtained, and even when the wheel is worn
out it may again be utilized by simply turning off the flange to the level of the
wheel tread, so that a new rolled tyre of any suitable thickness can be shrunk on or
fastened thereto, as the worn-out wheel serves as a skeleton wheel centre, and when
so retyred the same lasts for an indefinite period, as it becomes equal to new.
Another advantage is that in applying this improved form of wheel to wrought-
iron built-up wheel body centres, lighter steel tyres may safely be used than have
hitherto been employed, and by stopping off or leaving off the flange of such
improved wheel it can readily be adapted for use for omnibuses, waggons, and other
vehicles running on ordinary roads.
The short curved arms or supports before described greatly increase the elasticity
of the wheel, as before stated, at the same time that the rim or tyre of the wheel is
much more firmly and strongly supported thereby where most needed, and conse-
quently much greater strength is obtained, thus rendering the wheel capable of
withstanding the severe break power now so frequently applied thereto.
Each wheel is cast at a single operation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Hadfield in the Great Scal Patent Office on the 24th
February 1879.
ROBERT HADFIELD, of Sheffield, in the County of York. IMPROVEMENTS IN
THE MANUFACTURE OF WHEELS FOR TRAMWAY AND RAILWAY CARRIAGES AND
TRUCKS AND OTHER VEHICLES."
"
My present Invention relates to improvements in the manufacture of a similar
class of wheels to that for an improved manufacture of which Letters Patent were
granted to me on the 20th day of January 1877, No. 264. Wheels manufactured
upon the improved principles described in the Specification of such Letters Patont
have proved excellent wheels, but are found in practice to be difficult and expensive
to cast, while the lighter wheels are apt to twist and warp, and thus lose the truth
of their form.
My present improvements consist in casting in steel at a single operation ordinary
locomotive, tramway, and railway wheels, which are complete in themselves. Such
wheels are made with six or any other convenient number of straight oval arms,
hereafter called the main arms; springing from the boss or nave of the wheel, each
of which main arms diverges or radiates at its outer extremity into two short
curved oval arins or supports, terminating at the rim or tyre of the wheel. Thus
a wheel having six of such straight arms springing from the boss or nave would
have twelve short curved arms or supports joining on to the inner periphery of the
rim or tyre. These curved oval arms or supports do not increase the weight of the
wheel, as the intermediate spaces between the main arms, as also between such
outer curved arms, are left hollow, whereby great lightness and elasticity is imparted
to the same. The number of such main and curved oval arms may be varied
according to the size and strength of the wheel to be manufactured. Such steel
wheels are moulded from a wood or metal model in the ordinary steel moulder's
composition, after which such moulds are dried and the molten steel cast therein.
Such wheels are then carefully heated and cooled or annealed, after which they only
require turning and boring to be ready for use, or, in the case of tramway wheels,"
they require boring only.
Such improved wheel is not only less expensive, but is also easier and simpler to
cast than that described in the Specification of my said Letters Patent, No. 264, of
1877, and when steel wheels are cast to this design they readily adapt themselves
to the great contraction and expansion which occurs when casting steel wheels for
railway or trainway purposes. The contraction in steel being double that of cast
iron will illustrate some of the difficulties which have to be overcome.
My improved wheel also possesses much greater elasticity than the ordinary wheel,
and is therefore enabled to better withstand and resist the great and sudden shocks
to which railway, tramway, and locomotive wheels are exposed, while its form.
renders it specially adapted for resisting the sudden application of brake power,
which at present so seriously and injuriously affects the ordinary built-up wheels.
The numerous advantages possessed by my improved cast-steel wheel over the
wheels in ordinary use may be briefly summarized as follows:-
1stly. Each wheel is cast at one single operation, whereby the cost of manufacture
is greatly diminished.
2ndly. The actual use of all the steel in the wheel tread is secured, and thus double
the life of an ordinary, tyre is obtained, and even when this cast-steel tread is
worn out such wheel can be further utilized by turning off the flange to the level
of the wheel tread, when a new tyre can be shrunk on or otherwise fastened
thereto, so that when the wheel is actually worn out it can be again used as a
skeleton wheel centre, thus effecting a very great economy.
3rdly. By stopping or leaving off the flange of my improved wheel the same can
be readily adapted for omnibuses and other vehicles running on ordinary roads,

page_text: P
4thly. By using the short-curved outer oval arms or supports herein-before
described great elasticity is obtained.
5thly. Also by the use of such short branched or curved oval arms the wheels
are prevented from breaking or rupturing from internal strains whilst cooling after
being cast.
Gthly. In this improved form of wheel there is no strain whatever on the wheel
body, for the simple reason that whilst the wheels are being cast the contraction is
perfectly equal all round, and such wheel is specially adapted for resisting the
sudden application of brake power.
7thly. These wheels are not only free from the defects of ordinary built-up wheels,
but can also be made cheaply, and are not injurious to either the rolling stock or
permanent way of a railroad or tramway.
Figure 1 of the accompanying Drawings shews a plan view of one of my improved
cast-steel railway wheels, and Figure 2 shews a sectional view of the same taken at
lines A, B, a, b, Figure 1; and Figures 3 and 4 shew similar views of one of iny
improved cast-steel tramway wheels, Figure 4 being a sectional view taken at
lines C, D, c, d, Figure 3.
Having now set forth the nature of my said Invention of "Improvements in the
Manufacture of Wheels for Tramway and Railway Carriages and Trucks and other
Vehicles," I would here remark that I am aware that wheels of a somewhat similar
form to that herein-before described have been in use for barrow wheels; such
wheels however are cast either in malleable iron or inade of wrought iron and are
built up by mechanics, and are perfectly useless for tramway or railway purposes..
I wish it however to be distinctly understood that I do not claim the peculiar form
of wheel herein-before described in respect of any wheels made in a similar way to
such barrow wheels; what I claim and desire to secure by the herein-before in part
recited Letters Patent is,-.
1°. The casting of railway, tramway, and ordinary locomotive wheels, as also of
wheels for railway trucks in steel, in the manner herein-before described.
. 2°. I claim the peculiar form of such cast-steel wheels, as herein-before described
-and-illustrated, for the reasons herein before set forth.
3°. I claim the utilizing my improved cast-steel wheel for omnibuses and other
vehicles running on ordinary roads by stopping or leaving off the flange of the same,
substantially in the manner herein-before described and illustrated.
. In witness whereof, I, the said Robert Hadfield, have hereunto set my hand
and seal, this Twenty-first day of February, in the year of our Lord One
thousand eight hundred and seventy-nine.
DAD
ROBERT HADFIELD. (L.S.)