IM- PROVEMENTS IN RAILROAD FLEXIBLE TRUCKS
Year: 1878

page_text: LETTERS PATENT to Friedrich Hermann Felix Engel, Civil Engineer and
Patent Agent, of the City of Hamburg, Germany, for the Invention of "IM-
PROVEMENTS IN RAILROAD FLEXIBLE TRUCKS." A communication from George
Vincent, of San Francisco, California.
Sealed the 8th November 1878, and dated the 13th May 1878.
PROVISIONAL SPECIFICATION left by the said Friedrich Hermann Felix
Engel at the Office of the Commissioners of Patents on the 13th May 1878.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. "LMPROVEMENTS IN RAILROAD FLEXIBLE TRUCKS."
(A communication from George Vincent, of San Francisco, California.)
This Invention comprises a new and useful method in the construction of flexible
trucks, and new and useful devices and combinations of devices for making such
trucks positive and effective in their action and economical in cost of building.
My trucks have three axles, of which the end axles are placed within flexible
boxes, and have a compound lateral and forward and backward movement.
In order to make the wheels upon each side of the trucks follow each other
easily in the line of a curve around which the truck may be passing, it is necessary
that the axles should keep in a line with the radii of the curve. And in order
that the axles may conform to the various lines of the different radii of changing
curves, when the middle axle has no lateral movement in the truck, it is necessary
that the end axles should each respectively swing horizontally around a point that is
central between each end axle respectively and the middle axle.
In the main frame of the truck cross timbers are placed so that their centres
come half way between the middle and end axles of the truck, and a vibrating
sweep or sector, having its ends connected with the boxes of the end axle, turns
upon a pivot of the corresponding frame placed exactly central between the middle
axle and an end axle,

page_text: The desired result can also be accomplished without a sweep or sector in the
following manner -A circular slide connected to an axle box case, of cast steel or
other hard material, holding the corresponding axle box of each end axle, is fitted
to slide in a circular groove of an outer box case. The edges of the
groove and
slide are bevelled so as to prevent the slide from dropping out of the groove. The
circular groove must have its centre at a point that is exactly central between tho
four wheels of the middle axle and an end axle of the truck, when the three wheels
upon each side of the truck stand in a straight line with each other.
The ends of the axle boxes are furnished with round lugs upon which are sus-
pended the sides of stirrups, in the bottom of each of which a small ball is seated
in a shallow socket.
A second stirrup receives the crown of the ball in a shallow socket. These
second stirrups have downward bent sides, and the ends of same pass through holes
in the bottom of the corresponding outer box case and are secured by nuts. By
these means the end axles can move endways or laterally in the truck, and a 1
compound movement is imparted to them. They not only move endways but one
end of each axle goes forward while the other end goes backward in the truck, and
these compound movements of the end of the axles are in a line with the circum-
ference of a circle whose centre is of a point exactly central between the four
wheels of the middle axle and corresponding end axle of the truck, or in case a
sweep or sector is applied, as before described, in the centre of the corresponding
pivot around which the sweep or sector is vibrating.
The outer box cases rest upon equalizing bars which are in connection with the
frame of the truck through the medium of supporting coil springs.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich Hermann Felix Engel in the Great Seal Patent Office on
the 13th November 1878.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. "IMPROVEMENTS IN RAILROAD FLEXIBLE TRUCKS."
A communication from George Vincent, of San Francisco, California.
This Invention comprises a now and useful method in the construction of flexible
trucks, and new and useful devices and combinations of devices for making such
trucks positive and effective in their action and economical in cost of building.
The following is a full, clear, and exact lescription of the Invention, sufficient to
enable any person skilled in the art to which it belongs to construct and use the
same, reference being had to Sheet I. of the accompanying Drawings, in which,-
Fig. 1 is a bottom view of a truck fitted according to this Invention; Fig. 2 is
a side view of the same.
Fig. 3 is a bottom view of a truck frame, showing a portion of the detals of tho
Invention.
Fig. 4 is an enlarged view of the circular slot with the circular slide fitted in it,
and a pivoting axle box connected with the circular slide.
Fig. 5 is a side sectional elevation showing a large caso that slides up and
down in the pedestal, a bevilled edge of one side of the circular slide, the axle box
with suspending attachments and antifriction devices.
Fig. 6 is an end sectional elevation of what is shown in Figure 5.
In the Drawings similar letters and figures refer to corresponding parts in the
Drawings.
A is a main truck frame; B is one end of the end sets of truck wheels; C is
the middle set of truck wheels; D is the other end set of truck wheels; E is a
vibrating frame or sweep; H is a cross timber in the main frame; J are pedestals;
P is a pivot upon which the sweep E vibrates; I are the carrying springs; 2, 2, is
a metal plate, having in it a circular groove 3; 4 is a circular slide fitted to slide
in the circular groove 3; the edges of the groove 3 and slide 4 are bevelled, as
shown at Figure 6, so as to prevent the slide from dropping out of the groove; 5 is
an outer box or case, having vertical grooves 7, by means of which it is held in its
position by means of the vertical edges of the pedestals acting as guidos; 8 is an
axle box, of cast steel or other hard material, for holding the rabbited axle
box; 19 is a journal upon which the axle box case 8 pivots; it extends upwards
from the case 8 and penetrates the circular orifice in the middle of the slide 4.
This journal should be a little tapering, smaller at its outer or upper end; 11, 12,
and 13 are the three axles; 14 are round lugs upon each end of the axle box in
case 8; upon these lugs are suspended the sides of the stirrup 16; in the bottom of
the stirrup a small ball 18 is seated in a shallow socket; a second stirrup 17 receives
the upper apex of the ball in a shallow socket, the sides of the stirrup 17 bend
downwards, and their ends pass through holes in the bottom of case 5, and are
secured in their position by nuts 20; 21 are equalizing bars.
In order to make the wheels upon each side of the trucks follow each other easily
in the line of the curve, around which the truck may be passing, it is necessary that
the axles should keep in a line with the radii of the curve; and in order that the
axles may conform to the various lines of the different radii of changing curves,
when the middle axle has no lateral movement in the truck, it is necessary that the
end axles should each respectively swing horizontally around a point that is central
between each end axle respectively and the middle axle.
In Figure 3 H is a cross timber in the main frame, this cross timber H is placed
so that its middle comes half way between the middle, and end axles of the truck;

page_text: E is a vibrating sweep, having its end connected with the boxes of the end axle ;
these frames are connected together by the pivot P, which is placed in a position
that is exactly central between the middle axle and an end axle, that is to say, the
pivot P is half way between the middle and end axles, and is also in a line
that runs longitudinally with the truck crossing the axles at right angles exactly
half way between the wheels when the truck stands straight and the wheels upon
each side of it are in a straight line with each other. The Drawings show the
vibrating sweep E only between the axles 11 and 12, but it can also be placed
between the axle 12 and 13, the object of not putting it there in these Drawings is
to show how the desired results can be accomplished without using this vibrating
sweep; the slide 4 is held by and slides endwise in a circular slot or groove 3,
which is made to fit, and is held in the upper part of the box 5, which, in turn, is
held in the pedestals J; by these means the circular groove 3 and slide 4 are held
in their proper place in the truck, as are also the boxes in which the axles turn.
The circular groove 2, 2, should be placed in the truck so as to fall in line with the
circumference of a circle, whose centre is at the pivot P, that is to say, at a point
that is exactly central between the four wheels of the middle axle and an end axle
of the truck when the three wheels upon each side of the truck stand in a straight
line-with each other. The ends of the sweep E are perforated so as to allow the
journals 19 of the cases 8 to pass through and connect the sweep E with the
boxes.
The operation is as follows:-When the truck passes from a straight line upon a
curved track the curve of the track presses the forward wheels laterally out of the
straight line with the truck, this pressure is resisted by the wheels of the middle
axle which act as a fulcrum and impart the lateral pressure to the hind wheels ;
both forward and hind wheels yield to this pressure and move laterally in the truck
and out of a straight line with the middle wheels, carrying their axles with them;
the ends of the axles being confined in the boxes, and the motion of the boxes being
controlled through the medium of the journals 19 by the circular grooves 3 and
slides 4, and also by the sweep E, the end of the axles are compelled to follow the
circular direction of the grooves 3; this direction is exactly the same and identical
with the direction of the perforated ends of the sweep E as it moves around the pivot C.
This direction is in the circumference of a circle, having its centre at the pivot P;
by these means, as the axles 11 and 13 are moved endwise or laterally in the
truck, a compound movement is imparted to them; they not only move endwise,
but one end of each axle goes forward while the other end goes backward in the
truck, and these compound lateral, and forward, and backward movements of the
ends of the axles are in a line with the circumference of a circle whose centre is at
the central point where the pivot P is placed, as before described. It has been
ascertained that this compound forward and backward lateral and circular motion
of the ends of the axles may be obtained by the use of the circular grooves 3 and
slides 4 without the sweep E. It may also be obtained by the sweep E or any sweep
of similar action without the circular grooves 3 and slides 4, or such grooves and
slides and sweeps may be used together. Circular ribs and other mechanical devices
inay be substituted for the devices which have been herein described for obtaining
the compound motion for axles.
When the compound, lateral and forward and backward and circular motions of
the ends of the end axles of the truck are obtained, and are made in a line with the
circumference of a circle, as has been described, the wheels upon each side of the
truck will follow each other in a line with the track upon which they are running,
whether such line is straight or curved, and if such line is a curve the axles of the
truck will automatically fall in line with the radii of such curve.
In the flexible truck here described it is important to prevent as much as possible
any movement endwise by the middle axle. In order to prevent such end motion
bars 23 are placed across the ends of the axle, fastening the bars to the outer case 5,
so they will not follow the up-and-down motion of the car and pedestals which the

page_text: เ
yielding springs permit, but will constantly maintain the same relative position to
the ends of the axle. Through each of the bars 23, immediately opposite the contro
of each end of the axle, an iron or steel bolt 24 is screwed, far enough to come in
contact with the flat end of the axle, or a small socket may be made in the axle,
and the end of the bolt 24 made to fit and penetrate the socket; jam nuts 22 may
be screwed upon the outer ends of the bolt 24 to prevent the possibility of their
being accidentally moved in their position.
By these devices any perceptible end play with very little or no increase of
friction is prevented, indeed, it is probable that there is less friction when these
devices are used than there would be if they were not used. If the weight of the
car body and load were to rest upon the plate 2, 2, and slide 4, it is obvious that
great friction would be constantly encountered by the sliding surfaces of the slides
4 and the bottoms of the grooves 3.
One object of this Invention is to get rid of this friction as much as possible, and
this is accomplished by means of the stirrup 16 hung upon the lugs on the axle box
case S, with the ball 18, and the second stirrup 17 with its fastenings. The opera-
tion of these devices is as follows:-The weight of the car body with its load rests
upon the equalizing bars through the medium of the coil springs I in the usual
manner. The ends of the oqualizing bar rests upon the top of the case 5, as shown
in Fig. 2; a recess in the top of the case 5 for receiving the end of the equalizing
bar is shown in Fig. 6; the weight is thus thrown upon the case 5; the case 5 is
held up by the second stirrup 17, which rests upon the top of the ball 18; the ball
18 is in turn carried in the first stirrup 16; and the stirrup 16 is hung to the lugs
of the axle box case 8, which, through the medium of the axle box, is carried by
the axle.
No part of the load rests upon the slide 4, which in this present arrangement
acts as a guide. The lugs 14 and journals 19 act as a universal joint at one end of
the stirrup 16, while the ball 18 with its sockets act as another universal joint at
the other end of the stirrup 16. As the weight is transmitted from the end of
the equalizing bar to the axle through these universal joints and the stirrup 16,
and as these parts work freely the end of the axle and slide 4 moves backwards
and forwards in the circular groove 3 without any considerable friction.
Any mechanic skilled in the art of building railroad trucks will know the size
aud proportions and material proper to be used in this Invention, and will also know
how to substitute other forms of stirrups and universal joints for those herein speci-
fically described.
The bolts 24 can be used to prevent lateral play in any of the axles should it be
desirable. These bolts, and also the stirrups and universal joints, are designed to
apply to any form of flexible railroad trucks, both car trucks and locomotive trucks,
and also to trucks in which the lateral motion is in the middle axle, as well as
where such lateral motion is in the end axles.
Where the stirrups with the universal joints are applied to the leading and
trailing wheels of locomotives the driving wheels, whether there are two, four, or
six of them, should be under the middle of the locomotives half way between the
leading and trailing wheels; and the stirrups, universal joints, and connecting devices
should be applied, as herein described, with the leading and trailing wheels. The
leading and trailing wheels may be of any desired size.
A modification in car trucks or the self-acting mechanism, by which they accomo-
date themselves to the varying curvature of the road, consists in a novel method of
hanging the boxes in which the journals of the axles are supported, and in a means
of connecting the leading and trailing wheels of the truck, so that they will con-
form to the curvature of the road, and act upon each other independently of the
central pair of wheels.
This modification is shown on Sheet II. of the accompanying Drawings. The
nedestal A has a stout bar B across the lower nart and a loon or shackle C

page_text: rounds the bar, so that the shackle D may pass through it, and have a free swivelling
motion, the same as that by which the forward end of a truck for hauling goods
is suspended from its front axle. The shackle D encloses the box E, passing
across the top and resting upon the pin F, as shown; this pin passes through
the two sides of the fork G of the arm H, and this arm is bent round so as to
connect the boxes at each end of the axle with the longitudinal central bar I, as
shown. This bar is pivoted to the frame at a point J, midway between the centre
and the end axle, and it also lias a bolt K uniting it with the similar bar from the
opposite end of the truck, a small slot allowing them sufficient motion upon each
other. The bolt J is of sufficient length to allow a vertical movement of the bars
to accomodate themselves to the action of the equalizing levers L, which are
mounted upon the springs M, and adjust themselves and the outer or skeleton box
to the irregularities of the road, this box moving in guides in the pedestal. It will
be seen by this construction and method of swinging the boxes in the shackles D
that the adjustment to any curve is easily made, and the pressure required to over-
come the friction of the moving parts will be reduced to a minimum. The end of
the axle enters its box, and has a thrust bearing N which receives all end thrust,
and thus relieves the shoulder at the inner end of the box of all wear. A
rabbetted cap O fits over the end of the axle, and is flattened at the sides, so as to
drop into the box, and is prevented by its shape from turning. A. sliding plate P
drops in at the other end, and retains the parts in place.
The whole action is very simple, easy to get at and keep in repair, and its move-
ment is prompt, even in the smallest curves.
In the present case, where equalizing bars are used, it will be manifest that the
whole mechanism is supported at four points, that is, upon the springs M; but
when desired the equalizing bara may be dispensed with, and the frame supported
upon six equidistant spiral springs. The leading and trailing wheels may then be
brought nearer together, and the wheel base correspondingly diminished.
Having thus described the said Invention, what I claim as new and desire to
secure by Letters Patent are,-
1st. A car truck constructed with end axles, the ends of which have a compound
lateral and forward movement when such movement is upon a line with the
circumference of a circle, substantially as and for the purposes herein set forth.
2nd. The curved slot or groove 3 and slide 4 or their equivalent in a railway
truck, substantially as and for the purposes herein set forth.
3rd. The frame or sweep E vibrating around the central point at the pivot P,
substantially as and for the purposes set forth.
4th. The box case 3 for holding the rabbitted box 10, and to sustain friction
without wearing, substantially as herein set forth.
5th. The plate 2, 3, made hard to sustain friction without wearing out fast, sub-
stantially as hercin set forth.
Gth. The journal 19 attached to the axle box, substantially as herein set forth.
7th. The method of avoiding friction in the working devices by which rail-
road trucks are made flexible by substituting a stirrup and universal joints in
lieu of sliding surfaces, where the weight of the car bears, substantially as herein
described.
8th. The combination in a flexible railroad truck of the case 5, stirrups 16 and
17, ball 18, lugs 14, and journal 19, substantially as and for the purposes
specified.
9th. The bolts 24 arranged to prevent lateral play in the axle of flexible railroad
truck, substantially as and for the purposes specified.
10th. The combination of the vibrating axles and equalizing bars with the
stirrups containing universal joints, substantially as and for the purpose herein
specified.
11th. The modification of hanging the boxes in which the journal of the axles
are supported, and the ineans of connecting the leading and trailing wheels of the

page_text: truck, substantially as described, and shown in Sheet II. of the accompanying
Drawings.
In witness whereof, I, the said Friedrich Hermann Felix Engle, have hereunto
set my hand and seal, this Seventh day of November, One thousand eight
hundred and seventy-eight.
FRIEDRICH HERMANN FELIX ENGEL. (L.S.)