IMPROVEMENTS IN THE MANUFACTURE OF RAILWAY CARRIAGE AND OTHER WHEELS FORMED OF CAST METAL, OR HAVING CAST-METAL NAVES OR BOSSES
Year: 1857

page_text: LETTERS PATENT to William Grindley Craig, of Gorton, in the County,
of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF RAILWAY CARRIAGE AND OTHER WHEELS FORMED OF CAST
METAL, OR HAVING CAST-METAL NAVES OR BOSSES."
Sealed the 1st April 1858, and dated the 8th October 1857.
PROVISIONAL SPECIFICATION left by the said William Grindley Craig
at the Office of the Commissioners of Patents, with his Petition, on
the 8th October 1857.
I, WILLIAM GRINDLEY CRAIG, of Gorton, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF RAILWAY CARRIAGE AND OTHER WHEELS FORMED
OF CAST METAL, OR HAVING CAST-METAL NAVES OR BOSSES," to be as follows:-
This Invention refers to that class of wheels formed of cast metal, or
having cast-metal naves or bosses, principally intended to be secured on an
axle, such as railway carriage wheels. The object of the Invention is to cast
the hole in the nave or boss in which the axle is fixed, and also the key bed
for securing the wheel on the axle, so accurate and true as to dispense with
the boring and key-bed cutting, which is necessary when the boss or nave of
the wheel is formed by the ordinary mode of casting. Boring the hole and
casting the key bed are indispensable with the ordinary mode of casting, as
the core to form the hole in the boss or nave is constructed solely of "green
sand," and is held in its position in the mould boxes merely by the core prints
left in the sand of the upper and lower box, these core prints being seldom, if

page_text: ever, strictly accurate in position, as they are generally disturbed by the with-
drawal of the pattern.
My Invention consists in an improved construction of core, and in arrange-
ments whereby the core is more accurately formed, the special object of these
arrangements being to enable the core when formed to be correctly placed
and held; and also in arrangements by which the boxes may truly fit each
other, and hold the core in its correct position; and also in arrangements in
the construction of the pattern, so that it may be accurately placed in and with-
drawn from the mould boxes. The core box is formed of metal in two halves,
and is correctly bored and turned, so that one end will fit concentrically
in a base plate or table having a conical centre, which is provided for the
purpose of holding in the axis of the core box a hollow metallic centre, upon
which the core is formed. The core may be also formed on a hollow metallic
centre with loam without a core box, in the same manner as ordinary loam
The mould boxes are truly turned to fit each other, the upper box
having a hole bored in it to receive the end of the metallic centre of the core.
The pattern is of metal, and is constructed so as to fit in an exact central
position when in the mould boxes; a conical metallic print fits accurately in a
recess in the lower side of the pattern, in which it is secured by a set screw;
this conical print corresponds to the conical centre on the base or table plate
upon which the core box is placed when the core is formed. Before the
pattern is removed from the mould box the set screw is taken out, so that
when the pattern is withdrawn from the box the metallic print is left
undisturbed in the sand. When the core is placed in the mould, the hollow
metallic centre is held centrally by the metallic print (upon which it rests),
and by the hole formed in the metal of the upper box. With these arrange-
ments the core is truly formed, and correctly held in the mould boxes while
the wheel is cast.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Grindley Craig in the Great Seal Patent Office on
the 8th April 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GRINDLEY CRAIG, of Gorton, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Eighth day of October, in the year of our Lord

page_text: One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did for Herself, Her heirs and successors, give and grant unto me, the
said William Grindley Craig, Her especial license, that I, the said William
Grindley Craig, my executors, administrators, and assigns, or such others as
I, the said William Grindley Craig, 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 Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF RAILWAY CARRIAGE AND OTHER WHEELS
FORMED OF CAST METAL, OR HAVING CAST-METAL NAVES OR BOSSES," upon the
condition (amongst others) that I, the said William Grindley Craig, 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 Office, within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said William Grindley Craig, 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 and accompanying Drawings (that is to say) :-
My Invention refers to the manufacture of that class of wheels which are
formed of cast metal, or which have cast-metal naves or bosses, principally
intended to be secured on axles, such as railway carriage and other wheels.
The object of the Invention is to cast the hole in the nave or boss in which
the axle is fixed, and also the key way or bed for securing the wheel on the
axle, so accurate and true as to dispense with the boring and key-bed cutting,
which is necessary when the boss or nave of the wheel is formed by the
ordinary method of casting. This boring and key-bed cutting is indispensable
with the ordinary mode of casting, as the core to form the hole in the boss or
knave of the wheel is constructed solely of "green sand," and is held in- its
position in the mould boxes merely by the core prints left in the sand of the
upper and lower box, these core prints being seldom, if ever, strictly accurate
in position, as they are generally disturbed by the withdrawal of the pattern:
My Invention consists in an improved construction of core, and in arrange-
ments whereby the core is more accurately formed, the special object of these
arrangements being to enable the core when formed to be correctly placed
and held; and also in arrangements by which the boxes may truly fit each
other, and hold the core in its correct position; and also in arrangements in

page_text: the construction of the pattern, so that it may be accurately placed in and
withdrawn from the mould boxes.
The nature of my improved arrangements will appear from the following
description, and the accompanying Sheet of Drawings, illustrating my Inven-
tion in its application to the construction of railway carriage wheels having
wrought-iron spokes or arms in cast-metal naves or bosses. Fig. 1 is a plan
view, shewing the moulding bed a, with the boss pattern c laid in ready for
moulding; and Fig. 2, a section of the same. The horns of the moulding
bed are turned on the outside face, and a recess is turned on the upper and
inner edge to fit a corresponding projection on the moulding box (a¹); the core
prints c¹ of the pattern lie between the horns (6), and are held correctly in
position by the projections d, which fit on the turned part of the horns (6); a
pin or pivot (e) is fitted in the boss of the pattern c, to which it is held firmly
by a screw and washer 9, while the sand is being rammed in, and this pin
or print (e) is left in the sand when the pattern (c) is withdrawn, forming a
fixed turned metal centre to receive one end of the core. Figs. 3 and 4
represent a section and end view of the core box, shewing the method of
making the core. The bed h of the core box has a projection i upon it, which
is the counterpart of the upper part of the pin (e, Fig. 2), being turned to the
exact size, and the axis of the core is formed by a hollow metal tube k, which
is bored out at each end, (so that either end may be used) to fit in the pro-
jection on the bed h. The core box (h') is formed in two equal parts, with a
faced joint, and stands on the bed h, which is faced up to receive it, and is
thus held together at its lower end, the upper end being secured by a metallic
ring 7, bored out to fit the turned projection m; the top end of the core bar k is
held and kept central in the core box (¹) by means of a three-armed clutch
or claw n, the inside edge of the claws being bored to fit truly the aforesaid
metallic ring, the centre of the clutch being provided with a projection o,
exactly corresponding with the one (i) on the bed h of the core box, and
.also the pin e, Fig. 2. Thus the core box is held truly in the centre of the
boss, while the sand is rammed in. Figs. 5 and 6 shew another method of
making the core. The axis of the core is formed by a hollow tube k, as
before described, which is bored to fit at each end similar projections to those
(e and i) shewn in Figs. 2 and 4; but in addition this core bar (k) is furnished
with two collars p, one at each end, turned to the diameter required for the
core. The core is formed by mounting the core bar between the headstocks
of a lathe, the spacer being then struck up in loam.
A chill mandril may
be used instead of either of these methods; it would require boring at each
end, in the same manner as described for the core bars. The core may be

page_text: made either with or without a key way. Fig. 7 is a plan of the moulding
bed with the pattern removed, the arms (y) of the wheel laid in position, and
the moulding box (a) on the top part filled with sand; and Fig. 8 is a section
of the same. The moulding box is bored out at the centre to fit on the out-
side diameter of the core, and the lower edge of the outside shell of the box
is turned with a projection to fit truly into a recess on the upper and inner
edge of the horns (b) of the moulding box or bed (a), as before mentioned.
The moulding bed (a) is bored out at (s) to the exact diameter required for the
rim of the wheel, and the parts t are faced in order that the arms (y) may
lie flat and true. The groove u is left in the corner that the sand may be
easily cleared away. Now it is obvious that when the pattern of the boss is
removed, and the pin e is left in the sand, it forms a true and fixed centre for
the reception of one end of the core, which sitting on the pin is kept true at
its upper end by the centre of the moulding box (a¹), which again finds its
exact place from the recess in the horns (b) of the moulding bed (a). These
horns (6) being accurately divided, keep the arms or spokes (y) at equal
distances one from another, while the heads of the bed against which the arms
on their outside edges abut keeps them in a true central position. The metal
is run into the mould in either of the larger divisions of the moulding box
without a possibility of any part shifting, which is necessary for the trueness
of the whole.
Having thus fully described the nature and particulars of my said Inven-
tion, and the manner of carrying the same into practical effect, I desire it to
be distinctly understood that I do not confine myself to the exact details
herein described, as such may be varied or modified without departing from
the principle thereof, but claim as my Invention the arrangements herein-
before described for the construction of railway carriage wheels formed of
cast metal, or having cast-metal naves or bosses; particularly the use of a
loose metallic print or pin (e), turned and fitted into the pattern (c), which
print or pin is left in the sand when the pattern is withdrawn from the mould,
to receive a core having a metallic axis or core bar bored to fit the said print
or pin, and also the arrangements for forming the core, as described.
In witness whereof, I, the said William Grindley Craig, have hereunto
set my hand and seal, this Sixth day of April, in the year of our Lord
One thousand eight hundred and fifty-eight.