Forged Car Wheels and Machinery for Making the same.
Year: 1891

page_text: Date of Application, 7th Apr.. 1891-Accepted, 9th May, 1891
COMPLETE SPECIFICATION.
Forged Car Wheels and Machinery for Making the same.
I WILLIAM ANSON PEARSON the Younger, of the City of Scranton, County
of Lackawanna, State of Pennsylvania, United States of America, Mechanical
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
In the accompanying drawings,
Figure 1 is a cross section of the wheel through the centre.
Figure 2 is a plan view of the outside of one half of the wheel.
Figure 3 is a circular section (through a Figure 1) represented as a plan
section.
Figure 4 is a plan view of the inside of the wheel on a smaller scale.
Figure 5 represents on a large scale, a section of the periphery (through y y
Figure 4) showing the means of joining the centre to the tire.
Figure 6 is a side view of the hydraulic press used in forging the wheel.
Figure 7 is a vertical section of the upper and lower die and the annular
contracting matrix ;
Figure 8 is a view from above of the contracting matrix.
Figure 9 shows more in detail the parts marked j and g in Figure 8.
Figure 10 is a vertical section of the upper and lower die and the annular
contracting matrix, showing a modification of the method of operating the
same.
Figures 11 and 12 are respectively the half of a plan view and a side elevation of
the modification shown in Figure 10.
Figure 13 is a top view, and Figure 14 a side view of the ingot after forging.
Figure 15 is a top view, and Figure 16 a side section of the wheel centre as
completed.
My invention consists in a composite car wheel having a rolled steel tire and a
die forged steel centre consisting of a single piece having corrugations of a peculiar.
form; it also refers to the means employed for joining the centre to the tire and
it also has reference to the form and construction of the hydraulic press and annular
contracting matrix which are employed for forging the wheel.
In Figure a represents the rolled steel tire, provided with two small over-
hanging flanges running around its interior periphery, one being situated at the
outside edge of the wheel, and the other near the inside. These flanges are shown
more clearly in Figure 5, and lettered respectively m and n.
Referring again to Figure 1, b represents the centre. This is made from a casting
or ingot which is cast, forged or rolled approximately in the shape of the complete
centre, and then re-heated and dic-forged in a hydraulic press. In order to produce
a corrugated steel forging of this shape from a single piece of metal great pressure
is required, and the peculiar form of hydraulic press which I use for this purpose is
particularly described later on in this Specification.
After having been forged in the hydraulic press, the hole for the axle is punched
out while the forging still remains within the press, or it may be afterwards bored
out. The rim of the centre is then turned into shape. The rim contains upon its
periphery two overhanging flanges corresponding to those upon the inside of the
tire, and shown upon a large scale in Figure 5, at P and J.
The proper distribution of the strain between the hub and rim of the centre is
secured by deep radial corrugations extending all the way from the hub to the rim.
They are shown in the plan view in Figure 2 and Figure 4. Figure 3 is a circular

page_text: section along the line of greatest corrugation indicated by the line a Figure 1
and the extreme limits of corrugation are indicated by the lines of the section in
Figure 1.
It will be seen that the distance from the top of the inside extreme of the corru-
gation to the top of the outside extreme of the corrugation is greatest at a point
about half-way between the hub and the rim. This appears most clearly by
following the dotted parallel lines ww, ww¹ drawn on the lower half of Figure 1.
The interior corrugation swells gradually until it touches the line ww at the point.c
and then again retreats. The exterior corrugation also swells gradually until it
touches the line w¹ w¹ at the point. This may be more concisely stated by saying
that the amount of radial corrugation is greater at the point on the section indicated
by line line a' than at any other point.
:
The distribution of the metal in a wheel of this shape is an important feature.
The sections of the extreme limit of the corrugation both ways are shown in
Figure 1, and the points indicate respectively the centres of gravity of the hub
half of the inside and outside sections. In like manners and s indicate the centres
of gravity of the tire half of the sections. It will be seen that and r¹ are farther
apart than s and s¹.
2'
The purpose of this corrugation is fourfold. First, as above stated, it distributes
the strain between the hub and the rim across the width of the wheel, both at the
hub and periphery; secondly, the bulging rim of both the inside and outside edge
of the corrugation operates upon the principle of a double-plated-dished wheel and
admits of the necessary expansion and contraction of the wheel due to the pressure
of the tire. It must be noted that when the wheel is compressed the points a
become more distant from each other, which does not necessitate any violent strain
upon the wheel in any direction because between these points there are no straight
lines but only S shaped curves; thirdly, owing to the corrugations being greatest
on the line the base of support to the weight carried by the wheel is extended
towards the ends of the hub to the greatest practicable distance, and the maximum
yielding strength is secured with a minimum of metal. Fourthly, the curves
produced by corrugations of this sort are best calculated to withstand the lateral
thrust of the wheel as it runs around a curve.
The tire is mar slightly smaller than the centre in inside diameter and is
shrunk upon it.
may; however, be simply forced upon it without shrinking.
The flanges m and n interlock with the corresponding flanges p and and at intervals
around the wheel bolts c c are passed and fastened either by a nut or by riveting.
These bolts are so placed that one half of each passes through the inner periphery
of the tire and one half through the outer periphery of the rim. The advantage of
this position of the bolt in combination with the two sets of overhanging flanges is
that every possible movement of the tire relative to the centre is absolutely
prevented while at the same time the tire may be removed by simply removing the
heads of the bolts.
The strongest tendency of a tire is to slip to the inside of the wheel as it passes
around a curve. This is effectually prevented by the interlocking flanges. Slipping
in the opposite direction is prevented by the bolts which are sufficiently strong for
the purpose, as the strain in this direction is very slight. Any circular slipping of
the tire upon the centre when the brakes are applied is prevented by the bolts
passing partly through the centre and partly through the tire; and lastly, in case of
fracture of the tire, its fragments are held from being thrown off centrifugally by
the overhanging shoulders of the flanges p and g, retained in position by the bolts.
In no other composite wheels have these four dangers been effectually guarded
against, except those in which the connection between the tire and the centre is
such that the former can only be removed by sawing it in two.
Having thus described the details of the wheel I shall now proceed to describe
the hydraulic press and the annular contracting matrix which are employed for
forging the wheel.
Figure 6 shows a large and strongly constructed hydraulic press, the details of

page_text: which it is unnecessary to describe. B is the lower and fixed die resting upon a bed
plate. The upper and movable die A is fixed upon the piston F.
C is an annular contracting matrix surrounding the upper die, fixed to the
independent pistons D D and capable of being lowered either by itself or in
conjunction with the upper die.
This matrix is shown in section in Figure 7. It consists of three rings, one above
the other, strongly bolted together. The upper and lower rings have an inside
diameter precisely that of the upper and lower dies, around which they fit
closely.
The inside diameter of the central ring is greater than that of the other two, and
its inside surface presents a bevelled edge tapering upwards, seen in section at hh,
in Figure 7. Its height is somewhat greater than the depth of the periphery of the
wheel centre which it is desired to forge. Within this central ring are a number of
segments e e. These segments have a height somewhat less than that of the central
ring, and consequently are capable of vertical play within the same.
The spaces
between the movable segments are filled with wedge shaped pieces or projections jj
having a depth equal to that of the movable segments and fixed around or forming
part of the upper part of the central ring, so that they extend down only as far as
the dotted line in Figure 7. The spaces between the bases of these wedge
shaped pieces form vertical slots k. At the back of each segment is a T shaped
lug (Figures 8 and 9) which is dovetailed into and runs in the slot k. The back
of each of the segments is bevelled to correspond with the bevel of the central ring
of the matrix, so that when they are in their lowermost position their inner edges
form a circle of greater diameter than when they are at the upper part of their
play. When they are in this latter position their inner edges form almost a complete
circle (indicated by the dotted lines in Figure 8) having a diameter almost that of
the wheel centre which it is desired to form.
It will also be seen that when they are in this latter position their upper and
lower edges will exactly correspond with those of the wedge shaped pieces which.
consequently will exactly fill the interstices between them.
The operation of the press is as follows:-A casting or ingot of approximately
the shape of the wheel centre is heated and placed upon the lower die, the con-
tracting matrix is then lowered until it surrounds the upper portion of this die, and
the movable segments in their lower position rest upon the lower dic, completely
enclosing the ingot. The upper die is then lowered. As soon as its face presses
upon the top of the wedges jj the matrix is forced to descend with it and the
movable segments being prevented from descending further by the lower die,
commence to contract. The result is that the pressure is simultaneously applied
to the top, bottom and sides of the ingot.
Other methods of actuating the segments e may be employed without departing
from the spirit of my invention, which contemplates the simultaneous contraction of
these segments along with the descent of the upper die.
v
In Figures 10, 11 and 12, I have shown a modification of my device whereby the
movement of these segments is obtained by independent hydraulic pressure. As
before e e represent the segments, each of which is mounted upon the end of a
horizontal plunger u, the head of which plays within the hydraulic cylinder t
These hydraulic cylinders are disposed radially around the entire circumference of
the die. Both exits i o of all these hydraulic cylinders are respectively connected
with the circular pipes d d' by means of which the simultaneous actuation of all the
segments e and under precisely the same pressure is secured. The segments e are
no longer capable of any vertical movement, as in the device heretofore described,
their simple horizontal motion now effecting all that was previously accomplished
by the combined motion.
When the forging is completed the centre of the hub may be punched out, while
the forging is still in the matrix, the punch being operated by the piston head.
The complete forging is shown in Figures 13, 14, 15 and 16 showing the wheel
centre after it is turned off' to receive the tire.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. A composite car wheel having a die forged corrugated steel centre with radial
corrugations extending from the periphery to the hub struck from an ingot or
casting substantially as described.
2. A car wheel having a corrugated centre with radial corrugations which
increase in amount of corrugation to a point approximately midway between the
hub and the periphery and then again decrease substantially as described.
3. A car wheel having a die forged corrugated centre with radial corrugations,
the inside and outside extremes of which present in radial section curves concave
towards each other substantially as described.
4. A car wheel having a die forged corrugated centre with radial corrugations,
the inside and outside extremes of which present radial sections such that the
physical centres of the hub halves of these sections are further apart than the
physical centres of the tire halves, substantially as described.
5. In a composite car wheel the combination of the tire having around its inner
periphery overhanging flanges and the centre having around its outer periphery
corresponding and interlocking overhanging flanges and bolts passing through and
between the centre and the tire, approximately one half their width being embedded
in each, substantially as described.
6. In a press for forging the combination of the upper and lower dies, and a series
of circumferentially arranged radially acting dies adapted to contract simultaneously
with the compression of the upper and lower dies, substantially as described.
7. In a press for forging the combination of the upper and lower dies and an
annular matrix containing segments adapted to contract simultaneously with the
compression of the dies, substantially as described.
8. In a press for forging the combination of the upper and lower dies, an annular
matrix supported upon independent pistons, which matrix contains segments adapted
to be contracted simultaneously with the compression of the dies substantially
as described.
9. In a press for forging the combination of the upper and lower dies, an
annular matrix having on its inside a bevelled edge, a series of segments playing
against that edge, wedge shaped blocks between the segments, slots between
these blocks and lugs upon the back of the segments dovetailed into said slots
substantially as described.
:
10. In a press for forging the combination of the upper and lower dies and a
series of circumferentially arranged segments, each actuated by a horizontal
hydraulic cylinder and means substantially as described, whereby the simultaneous
action of all the said segments may be secured substantially as described.
Dated this 20th day of February 1891.
CARPMAEL & Co.,
Agents for the Applicant.