IMPROVEMENTS IN THE MANUFACTURE OF GROOVED TYRES FOR WHEELS "
Year: 1883

page_text: LETTERS PATENT to George Davies of Manchester in the County of Lancaster
for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GROOVED
TYRES FOR WHEELS
"
PROVISIONAL SPECIFICATION, left by the said George Davies at the Office
of the Commissioners of Patents on the 3rd March 1883.
GEORGE DAVIES of Manchester in the County of Lancaster
IN THE MANUFACTURE OF GROOVED TYRES FOR WHEELS
"
"
'IMPROVEMENTS
The object of this invention is to manufacture metal tyres (for wheels of
carriages) of a dovetail section in order to secure thereto or therein surface rings or
bands of india rubber or other compressible and elastic material.
In the manufacture of iron, steel, or other metal of a dovetail section by rolling,
it has not been found possible to roll both internal angles of the dovetail at one
time, and at the same time to maintain the flatness of the base, on account of
the internal width at the base of the channel being greater than that at the
mouth of the same.
In order to obviate this difficulty and to manufacture by rolling, metal of a
dovetail section with both angles sharply rolled and without any necessity for
bending or curving the base I propose according to my invention to roll the
two angles separately which I am enabled to do by my particular method of
manufacture and by the peculiar construction of the rolls which I employ.
I first roll an ordinary form of channel iron or other metal of about the section
required but with the sides vertical, and either parallel or slightly tapered, in the
usual manner with the base parallel to the axis of the roller.
For the next part of the operation I construct the rolls as follows. I turn &
certain portion of the roll (for a width about equal to the widest part of the outer
section required) to a conical form, tapering towards the axle (say from left up to
right) to such a taper that the edge of the cone forms with a circumferential groove
cut round the periphery at the base thereof, the exact angle required at the inside of
the dovetail on the left side. The depth of the circumferential groove is equal to

page_text: the depth of the side and the left side of the groove corresponds with the outer
form to be given to the side of the metal.
The length of the conical surface (from left to right) will be determined by a line
drawn parallel to the inner surface of the dovetail required and falling just within
the upper edge of the square sided channel iron.
The depth and form of the right hand circumferential groove will correspond
with the outside form of the said square sided channel iron.
The opposite roll is made with a suitable cone reversed, and recessed to such a
depth as will allow for the thickness of metal required in the base of the tyre.
It will now be obvious that if a length of ordinary square sided channel iron or
metal be slightly tilted over towards the left and passed through these conical
grooves it will be rolled into the dovetail section required so far as concerns the left
hand side and about three quarters to five sixths of the base.
I have a second similar conical groove prepared but tapered in the reverse
direction, and by tilting the partly rolled iron or metal over to the right and
passing it through this second groove the remaining angle of the dovetail will be
formed and the required section produced by positive rolling.
According to another method I first roll channel iron or metal in the form of
three sides of a rhomboid by means of the same kind of tapered rollers as those
above described; the acute angle between the base and one of the sides being
equal to the angle of the dovetail required, on rolling the metal again in a reversed
conical groove the second angle of dovetail is produced as before.
A further modification of the invention consists in first rolling a square section
channel iron with a flat base, and then bending over the sides to the required
dovetail by means of rolls so constructed as to hold the base flat whilst the sides
are being bent over.
For this purpose I construct the rolls as follows. The bottom roll is made
cylindrical and either quite plain or with a circumferential depression corres-
ponding with the breadth and depth of the base. The upper roll is made
with a central collar or solid cylinder between two grooves. The width of
the collar is equal to that of the mouth of the dovetail and the diameter of this
central collar or cylinder is such that it rolls on the inside of the base keeping
it fat and preventing the rise of the corners whilst the sides are being bent in.
The depth of the grooves is equal to the height of the sides of the dove-tail
channel required and the outside of the groove is coned or bevilled to the outer
form of the dovetail section required so that the whole section (with the exception
of the inside corners) is supported during the operation of bending over the sides.
The lengths of dovetail section metal produced by either of these methods will
require to be bent to a circle by the ordinary bending rolls and the ends brought
together and welded to form a wheel tyre.
It will however be evident that weldless tyres can also be made on the same
principle.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Davies in the Great Seal Patent Office on the 1st September
1883.
GEORGE DAVIES of Manchester in the county of Lancaster
IN THE MANUFACTURE OF GROOVED TYRES FOR WHEELS
"
"IMPROVEMENTS
The object of this invention is to manufacture metal tyres (for wheels of
carriages) of a dovetail section in order to secure thereto or therein surface rings or
bands of india rubber or other compressible and elastic material
In the manufacture of iron, steel, or other metal of a dovetail section by rolling.
it has not been found possible to roll both internal angles of the dovetail at one
time, and at the same time to maintain the flatness of the base, on account of the
internal width at the base of the channel being greater than that at the mouth of
the same.
In order to obviate this difficulty and to manufacture by rolling, metal of a
dovetail section with both angles sharply rolled and without any necessity for
bending or curving the base I propose according to my invention to roll the two
angles separately which I am enabled to do by my particular method of manu-
facture and by the peculiar construction of the rolls which I employ and which will
be readily understood on reference to the annexed drawing and the following
explanation thereof.
I first roll an ordinary form of channel iron or other metal of about the section
required but with the sides a¹, a vertical and either parallel or slightly tapered, in
the usual manner, with the base b, b parallel to the axis of the roller, as shown at
Fig. 1.
For the next part of the operation I construct the rolls as follows. I turn a
certain portion of the lower roll (for a width about equal to the widest part of the
outer section required) to a conical form, tapering from the axle (say from left up to
right as at h Fig. 7.) to such a taper that the side of the cone forms with the
vertical edge of the groove at i, i the exact angle required at the inside of the
dovetail on the left side. The depth of the circumferential groove is, equal to
the depth of the side a¹ a¹ of the metal and the left side i, i of the groove
corresponds with the outer form to be given to this side of the metal
The upper roller is made with a reversed conical surface k, k (from left to right)
the width of which will be determined by a line drawn parallel to the inner surface
of the side a', a¹ and falling just within the inner upper edge of the square
side as, a. The depth and form of the circumferential groove 7, will correspond
with the outside form of the said square side a³, a' so that this side of the metal is
entirely supported whilst the side a is being formed. It will now be obvious that
if a length of ordinary square sided channel iron or metal Fig. 1. be slightly tilted
over towards the left and passed through these conical grooves it will be rolled into
the dovetail section required so far as concerns the left hand side a¹ and about
three quarters to five sixths of the base. I have a second similar conical groove
prepared, but tapered in the reverse direction see Fig. 3. and by tilting the partly
rolled iron or metal over to the right and passing it through this second groove the
remaining angle of the dovetail will be formed and the required section similar to
Fig. 3. will be produced by positive rolling.
According to another modification I first roll channel iron or metal in the form
of three sides of a rhomboid (see Fig. 4) by means of the same kind of tapered roll
as those above described (see Fig. 2) the acute angle between the base and one of the
sides being equal to the angle of the dovetail required. On rolling the metal again
in a reversed conical groove as at Fig. 3. the second angle of the dovetail is
produced us before.

page_text: A further modification of the invention consists in first rolling a square section
channel iron or steel with a flat base (Fig. 1) and then bending over the sides to
the required dovetail by means of rolls so constructed as to hold the base flat
whilst the sides are being bent over (see Fig. 5). For this purpose I construct the
rolls as follows. The bottom roll is made cylindrical and either quite plain or with
circumferential depression m, m corresponding with the breadth and depth of the
base b, b. The upper roll is made with a central collar or solid cylinder n, n
between two grooves o, o.
The width of the collar n, n is equal to that of the
mouth of the dovetail and the diameter of this central collar or cylinder is such
that it rolls on the inside of the base b, 6 keeping it flat and preventing the rise of
the corners whilst the sides are being bent in. The depth of the grooves is equal
to the height of the sides of the dovetail channel and the outside of the grooves o, 0
is coned or bevilled to the outer form of the dovetail section required so that the
whole section (with the exception of the inside corners) is supported during the
operation of bending over the sides.
As the base b, b must be perfectly square at the corners m, m the depth of the
side grooves o, o must be just sufficient to put a downward thrust upon the upper
edge of the side a¹, a³ so as to prevent the corners of the base from rising. When
it is desired to manufacture a dovetail section with vertical sides I roll the metal
in the ordinary way to the form shown at Fig. 6. and then by passing it through a
square sided groove bend the sides in as shown by dotted lines. The lengths of
dovetail section metal produced by either of these modifications will require to be
bent to a circle by the ordinary bending rolls, and the ends brought together and
welded to form a wheel tyre as before described. It will however be evident that
weldless tyres can also be made on the same principle.
Having now described, the nature and object of the said invention together with
the manner in which the same is to be or may be performed or carried into practical
effect I wish it to be understood that I claim as my invention the manufacture of
grooved tyres (for wheels of carriages) of a dovetail or other similarly undercut
section, without bending or curving the base, substantially in the manner
hereinbefore more particularly set forth and described, and more particularly
I claim
First rolling each angle separately by means of conical rolls as described with
reference to Figs 2 and 3.
Secondly, rolling one angle and bending the other also by means of conical rolls
as described with reference to Fig 4. and
Thirdly I claim rolling both sides, at right angles and bending both over at once
to the angle required by means of cylindrical rolls of the form as described with
reference to Figs 5 and 6.
In witness whereof I the said George Davies have hereunto set my hand and
seal this twenty second day of August in the year of our Lord One thousand eight
hundred and eighty three.
DETRA