Improvements in the Rolling Stock of Railways and Tramways.
Year: 1892

page_text: Date of Application, 15th Nov., 1892
Complete Specification Left, 14th Aug., 1893-Accepted, 7th Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Rolling Stock of Railways and Tramways.
I, RAYNES LAUDER MCLAREN, of 96 Addison Road, Kensington in the
County of London, Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention has for its object an improved construction of flexible wheel base
for the vehicles and engines of railways and tramways, that shall avoid the
disadvantages arising from the use of flexible wheel bases as heretofore
constructed.
According to my invention I employ three wheel frames, each carrying one or
more wheel axles, the axle or axles of the central frame being arranged with inde-
pendently revolving wheels and made to slide transversely on the under frame, in
order to take up any lateral displacement, such wheel frame being entirely
independent of the end wheel frames so that each frame can have its position
adjusted in a radial direction independently of the others, which would not be
possible if the three frames were connected by articulated connections, as is the
case with many arrangements of the kind heretofore employed.
The end frames are each pivotted to the under frame at a point which is nearer
to the centre of the end frame, than to the centre of the middle frame or are
arranged to be in effect so pivotted. ´
Each of the three frames has spring pressure applied to it so as to tend to keep
it in the central position, the strength of such springs being so proportioned that
those of the end frames can yield easier than those of the middle frame.
By the above described arrangement I promote the easy running of the vehicles
when entering and leaving curves and especially when passing over reverse curves,
as the axles are perfectly free to assume radial positions independently of each
other on any curve.
By fitting the middle frame with independently rotating wheels and by keeping
it independent of the end frames except through the relative spring action on the
under frame, I enable the middle frame to slide in its guides across the under
frame without binding or sticking and I avoid all the evil effects of the wheels of
this frame running on unequal diameters.
Also by allowing greater facility of action to the end frames, I ensure that the
pivot points of the same shall always be kept on or outside the centre line of the
gauge, and the radiating effect thus obtained over the end axles by the tractive
force applied to the draw bar is always exerted to force the end axle towards the
inner rail on curves.
Since the coning of the end axle wheel tyres will vary with wear and since
the difference between the lengths of inner and outer rails on curves varies with
each curve, it follows that the power absorbed by the sliding of the end axle
wheels must also vary and I therefore prefer to make all the wheels under the
vehicle capable of independent rotation but it will easily be seen that this feature
is not of such primary importance to my invention as is the fitting of the central
wheel frame with independently rotating wheels. Further I prefer to use such
wheels in every frame on account of their action easing the wrench on the wheel
frames, axle guards and boxes.
By employing independently rotating wheels in conjunction with a radiating
truck 1 reduce the resistance of the wheels to the sliding force exerted by the
under frame pushing on the pivot point and I am therefore able to move the said
pivot point into a position more nearly approximating to the correct one for all

page_text: curves and thus avoid the injurious wear resulting from too decided a tendency to
run towards one of the rails.
Having thus done away with the rigid obliquity of the wheels to the rails at
every point, counteracted the evil influence of the centre frame wheels running on
different diameters and enabled said frame to slide across the under frame without
sticking I am free to run all the wheels tighter to gauge than would otherwise be
the case while I can at the same time employ a long wheel base and reduce end
overhang to a minimum thus ensuring the easy and steady running of the vehicle
and consequently saving of power.
The wheels being capable of independent rotation will not wear their tyres as
rapidly as wheels fixed rigidly to axles and the coning of the tyres can consequently
be lessened which will still further reduce side boxing when running on tangents.
By thus distributing the wheels under the vehicle as well as reducing the racking
strains on wheel frames and under frame which result from wheels rigid with their
axles, wheel frames articulated up to one another and other causes I am enabled
to construct a vehicle for the same duty of lighter scantling and consequently of
more dead weight than would otherwise be the case, which on lines involving heavy
gradients and sharp curves is of the very greatest importance.
I prefer to use one axle only to each frame and thus have a six wheeled vehicle
but when necessary, I may have two axles in the centre frame or one axle in centre
frame, and two in cach end frame, the former being the most preferable arrangement.
Of course I could use four frames having one axle each, but this would not be
advisable.
The arrangement of the middle wheel frame and of the two end frames may be
variously modified for carrying out my above described invention.
In the arrangement which I prefer to employ, I construct the middle frame with
two longitudinal bearers one on each side of the longitudinal centre line, and
between these I fix guides in which a centre block can slide to a limited extent,
this block has a central hole in which fits a vertical pin, passing down from the
centre of the under frame. Against each side of the block bears a rod passing
through the before mentioned bearers and connected at their outer ends to the
middle of a blade spring, the ends of which are secured to supports on the
bearers.
Thus these springs, in acting against the block which is secured by the centre
bolt to the under framing, will tend to keep the centre wheel frame in the middle
position.
The wheel frame is in addition guided in its transverse motion by suitable
guides preferably situated at the four corners thereof and fixed to the under
frame.
I may however use a spiral check spring and buckle or other equivalent
device.
The two end wheel frames are constructed in the same manner as the centre
frame, with the exception that in this case the sides of the sliding block are made
with a curvature, the radius of which is struck from the centre pin on which the
frame is pivotted.
In the centre frame I may combine a revolving motion with the transverse motion
in order to ease further the flange pressure at curve entrances by curved guides at
the corners of the sliding frame and a revolving pin in a centre guide, the curved
guides being compelled to move transversely with the axle frame, but at the same
time allowing motion to a certain extent round their centre. may also in any
frame connect up each wheel journal to the other on each side by a compensating
beam in order to equalize the pressure.
On well laid roads can support the under frame at the sides or corners of each
wheel frame, but on rough roads I may in order to avoid the evils of a large
amount of play between the axle boxes and their guides carry the load on to the
end frames at a central point while keeping the central frame receiving its load at
its sides. This enables the vehicle to ride easily over a very rough road and avoids

page_text: the rolling motion so common to bogie stock. I effect this by means of an
adjustable pivot contact allowing of motion athwart the vehicle only (or if pre-
ferable with ball and socket bearing surfaces) between wheel frame and its lateral
sliding connection to under frame, which enables the wheel frame to adjust itself
to the road whilst still allowing it to receive its load, and at the same time traverse
across under frame in response to the spring or wheel pressure. When more than
one axle is fitted to an end frame a ball and socket pivot arrangement will provide
for a pitching as well as a rolling motion while leaving the sliding spring block
free to act.
In locomotives or other travelling motor frames, I prefer to use the Fairlie type
of construction, easing the flange pressure by the action of the radiating gear
using only one central axle under the fire box with wheel springs so adjusted that
the bulk of the weight is taken by the coupled end frame wheels, the central lateral
displacement springs being put outside the fire box space and all the springs made
relatively much stiffer than with carriage or wagon stock, whilst I lead the steam
or other source of power to the cylinders or power converter through a pivot
connection which is not a weight carrier.
I may adapt my divided axles to the coupled wheels of the driving mechanism
by employing a compound engine or at any rate two cylinders acting on the wheels
coupled together on the one side, and two cylinders acting on the wheels coupled on
the other side, the axles being coupled together at their centres for taking the
bending stresses in such a manner as to be capable of independent rotation.
I prefer to use the divided axle described in the Specification to my Patent
No. 21,047 of 1891 to ensure independently rotating wheels on main line work,
but on very light railway lines or on tramways any form of loose wheels or divided
axle which will answer may be substituted.
In order to ease the spring action I may apply the spring pressure whenever
feasible behind the end axles so as to give them a leverage over the spring pressure
and I may apply the spring pressure to the centre frame at centre, corners or sides
of frame and may combine a sliding circular block at each end as well as a die
block and pin in the centre of frame.
I may employ this system of flexible wheel base on any bogie truck, and I may
use it in conjunction with ordinary methods of attachment between under frame
and bogie frames or with a sliding die controlled by spring action on each side in
order to still further ease the shock on entering curves on to the body of the
vehicle.
Dated this 15th day of November 1892.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Rolling Stock of Railways and Tramways.
I, RAYNES LAUDER MCLAREN of 96 Addison Road, Kensington in the County
of London, 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:―
My invention has for its object an improved construction of flexible wheel base
for the vehicles and engines of railways and tramways, that shall avoid the disad-
vantages arising from the use of flexible wheel bases as heretofore constructed.
According to my invention I employ three wheel frames, each carrying one or
more wheel axles, the axle or axles of the central frame being arranged with
independently revolving wheels and made to slide transversely on the under frame,
in order to take up any lateral displacement, such wheel frame being entirely
independent of the end wheel frames so that each frame can have its position
adjusted in a radial direction independently of the others, which would not be

page_text: possible if the three frames were connected by articulated connections, as is the case
with many arrangements of the kind heretofore employed.
The end frames are each pivotted to the under frame at a point which is nearer
to the centre of the end frame than to the centre of the middle frame or are arranged
to be in effect so pivotted.
Each of the three frames has spring pressure applied to it so as to tend to keep
it in the central position, the strength of such springs being so proportioned that
those of the end frames can yield easier than those of the middle frame.
By the above described arrangement I promote the easy running of the vehicles
when entering and leaving curves and especially when passing over reverse curves
as the axles are perfectly free to assume radial positions independently of each other
on any curve.
By fitting the middle frame with independently rotating wheels and by keeping
it independent of the end frames except through the relative spring action on the
under frame, as well as by placing more weight on the end frames than on the
centre frame (by the use of lighter wheel springs and truss rods to under frame
capable of easy and accurate adjustment), I enable the middle frame to slide in its
guides across the under frame without binding or sticking and I avoid all the evil
effects of the wheels of this frame running on unequal diameters.
Also by allowing greater facility of action to the end frames, I ensure that the
pivot points of the same shall always be kept on or outside the centre line of the
gauge, and the radiating effect thus obtained over the end axles by the tractive
force applied to the draw bar is always exerted to force the end axle towards the
inner rail on curves.
Since the coning of the end axle wheel tyres will vary with wear and may vary
on the wheels fixed to the same axle and since the difference between the lengths
of inner and outer rails on curves varies with each curve, it follows that the power
absorbed by the sliding of the end axle wheels must also vary and I therefore
prefer to make all the wheels under the vehicle capable of independent rotation but it
will easily be seen that this feature is not of such primary importance to my invention
as is the fitting of the central wheel frame with independently rotating wheels.
Further I prefer to use such wheels in every frame on account of their action easing
the wrench on the wheel frames, axle guards and boxes.
By employing independently rotating wheels in conjunction with a radiating truck
I reduce the resistance of the wheels to the sliding force exerted by the under
frame pushing on the pivot point and I am therefore able to move the said pivot
point into a position more nearly approximating to the correct one for all curves
and thus avoid the injurious wear resulting from too decided a tendency to run
towards one of the rails.
Having thus done away with the rigid obliquity of the wheels to the rails at every
point counteracted the evil influence of the centre frame wheels running on different
diameters transferred some of the weight from the centre frame on to the end
frames and enabled said centre frame to slide across the under frame without
sticking 1 am free to run all the wheels tighter to gauge than would otherwise be the
case while I can at the same time employ a long wheel base and reduce end over-
hang to a minimum thus ensuring the easy and steady running of the vehicle and
consequently saving of power.
The wheels being capable of independent rotation will not wear their tyres as
rapidly as wheels fixed rigidly to axles and the coning of the tyres can consequently
be lessened which will still further reduce side boxing when running on tangents
while the side motion in the axle boxes can be reduced to a minimum.
By thus distributing the wheels under the vehicle as well as reducing the racking
strains on wheel frames and underframe which result from wheels rigid with their
axles, wheel frames articulated up to one another and other causes I am enabled to
construct a vehicle for the same duty of lighter scantling and consequently of less
dead weight than would otherwise be the case, which on liues involving heavy
gradients and sharp curves is of the very greatest importance.

page_text: I prefer to use one axle only to each frame and thus have a six wheeled vehicle
but when necessary, I may have two axles in the centre frame or one axle in centre
frame and two in each. end frame.
The arrangement of the middle wheel frame and of the two end frames may be
variously modified for carrying out my above described invention.
In the arrangement which I prefer to employ, I construct the middle frame with
two longitudinal bearers one on each side of the longitudinal centre line, and between
these I fix guides in which horizontal spindles can slide to a limited extent, against
a block passing down from the centre of the under frame. These spindles are
connected at their outer ends to the middle of a blade spring, the ends of which are
secured to supports on the bearers, and are inserted with an initial camber in order
to impart steadiness when running at speed on tangents.
Thus these springs, in acting against the block which is secured to the under
framing, will tend to keep the centre wheel frame in the middle position.
The wheel frame is in addition guided in its transverse motion by suitable guides
preferably situated at the four corners thereof and fixed to the under frame.
I may however use a spiral check spring and buckle or other equivalent device.
The two end wheel frames are constructed in the same manner as the centre
frame with the exception that they move round the pin on which the frame is
pivotted.
In the centre frame I may combine a revolving motion with the transverse motion
in order to further ease the flange pressure and ensure complete radiation of said frame
at curve entrances by using subsidiary guides at the corners of the sliding frame
these guides being compelled to move transversely with the axle frame, but at the
same time allowing motion to a certain extent round the centre of the frame. .I
may also in any frame connect up each wheel journal to the other on each side by
a compensating beam in order to equalize the pressure.
On well laid roads I can support the under frame at the sides or corners of each
wheel frame, but on rough roads I may in order to avoid the evils of a large amount
of play between the axle boxes and their guides carry the load on to the end frames
at a central point while keeping the central frame receiving its load at its sides.
This enables the vehicle to ride easily over a very rough road and avoids the
rolling motion so common to bogie stock. I effect this by means of an adjustable
pivot contact allowing of motion athwart the vehicle only (or if preferable with ball
and socket bearing surfaces) between wheel frame and its lateral sliding connection
to under frame, which enables the wheel frame to adjust itself to the road whilst
still allowing it to receive its load, and at the same time traverse across under
frame in response to the spring or wheel pressure.
When more than one axle is
fitted to an end frame a ball and socket pivot arrangement will provide for a
pitching as well as a rolling motion while leaving the sliding spring block free
to act.
In locomotives or other travelling motor frames I may adapt my divided axles to
the coupled wheels of the driving mechanism by employing in the case of steam
power a compound engine or at any rate two cylinders acting on the wheels coupled
together on the one side, and two cylinders acting on the wheels coupled on the
other side, the axles being coupled together at their centres for taking the bending
stresses in such a manner as to be capable of independent rotation.
For electric traction I use one motor to drive one of the axles and the wheels
coupled to it on the one side, and another motor to drive another axle and the
wheels coupled to it on the other side all the axles being divided ones or at any
rate having their wheels capable of independent rotation and mounted either on
ordinary bogie frames or on a rigid frame.
1 prefer to use the divided axle described in the Specification to my Patent
No. 21047 of 1891 to ensure independently rotating wheels on main line work, but
on very light railway lines or on tramways any form of loose wheels or divided
axle which will answer may be substituted."
In order to ease the spring action I may apply the spring pressure whenever

page_text: reastore Demma the end axies so as to give them a leverage over the spring pressure
and I may apply the spring pressure to the centre frame at centre, corners or sides
of frame. I may also use a curved sliding block in each end frame to take the
spring pressure the curved sides of such block being struck from the pivot centre of
the frame and working against similarly curved surfaces of guides fixed between
the spring bearers, the spindles conveying the spring pressure moving on the sides
of the block in a plane at right angles to their centre line.
Fig. 1 of the accompanying drawing shews partly in side view and partly in
longitudinal section three bogies to form a flexible wheel base according to my
invention, Fig. 2 is a transverse section of one of the end bogies, and Fig. 3 is a
plan of the three bogies shewing part of the underframe of the vehicle over the
left end bogie, the underframe over the middle and the right end bogie being
removed. It is to be understood that although in Figs. 1 and 3 the three bogies
are shewn near together, they are in reality some distance apart such for instance
as 8 or 9 feet from centre to centre of their axles. Each of the bogies is connected
as will presently be described to the underframe, but there is no other connection
of the one bogie to the other.
The middle bogie has a rectangular frame A A with 4 spring seats B, one at each
corner, receiving the ends of the springs and on these seats are planed faces bon
which bear the planed underfaces of the underframe C.
When subsidiary guides W are used they are inserted between the spring seats B
and the underfaces of the underframe C and slide between guides fixed to C as
shewn. They are provided with projections fitting into similar recesses on B,
whose sides are curved from D as a centre with a good fit but give circular play to
a limited extent around D as a centre. From the middle of the underframe projects
downwards a strong bracket D against each side of which abuts one end of a
sliding rod d, the other end of d bearing against a blade spring E. Clip safety
pieces a attached to the underframe project under the flange of the bogie frame A,
leaving sufficient freedom for slight relative movement of the underframe and bogie
to and fro and up or down. The bogie is free to move transversely subject to the
resistance of springs E. Each end bogie has also a rectangular frame A with
spring seats B at the corners taking the ends of the springs and having planed
faces b on which bear underfaces of the underframe C. A pair of safety clips a
project under the flange of the bogie frame A which is pivotted on a pin F and
provided with a bracket D, sliding rods d d and springs E E as in the centre frame.
The two end bogies are thus free to move transversely on their pivot pins F subject
to the resistance of the springs E, and this capability of movement of the end bogies
combined with the capability of transverse movement of the middle bogie gives
sufficient flexibility of wheel base to allow for considerable curvatures of the line;
and in order that there may be as little frictional resistance and wear of the tyres
as possible the wheels of each bogie are made free to rotate independently, by
employing divided axles or axles having their wheels capable of independent
rotation. These end bogies will usually take their load at their four corners but
on very rough roads I may use an arrangement similar to the following. Through
a sleeve e fixed in the underframe C passes a horizontal bolt forming the axis of a
hinge for a bracket D, which as described with reference to the middle bogie frame
is held between springs E and is capable of swinging round the pin whilst sliding
on the cross bearers which take the weight. For vehicles of less length, the
middle bogie may be dispensed with, only the two end bogies being employed, and
in that case the pivot pins F should be nearer the axles, and within the sides of the
frames A, the spring pressure being applied if necessary beyond the axles instead
of over or behind them. I have shewn the springs E as blade springs; obviously
they might be helical or volute springs.
Fig. 4 is an elevation and Fig. 5 is a plan partly sectional of a locomotive having
a four wheeled bogie, and three pairs of driving wheels, the bogie wheels on each
side being capable of independent rotation but not necessarily so; and the three
coupled wheels on the one side being driven independently of those on the other

page_text: side. For this purpose the axles of the driving wheels, are of the divided kind.
On the one side the driving wheel K has two cranks kk at right angles to one
another, the one driven from the cylinder L, the other from the cylinder L'.
Within the crank pin is a coupling pin m connected by side rods to the corre-
sponding coupling pins m of the two other driving wheels. The arrangement
of cranks and connections is similar on the other side of the locomotive. The
two receiver pipes between the cylinders are connected together by means of a
pipe in order to equalize the pressure on each side of the engine and means are
provided to admit high pressure steam to the low pressure cylinders in a compound
engine.
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 flexible wheel base for a railway or tramway vehicle, consisting of three
unconnected bogies, having wheels capable of independent rotation, each bogie
frame being connected to the underframe through springs allowing transverse
independent movement of each bogie, substantially as and for the purposes set
forth.
2. A flexible wheel base for a shorter vehicle consisting of two unconnected
bogies having wheels capable of independent rotation, each bogie frame being
pivotted to the underframe so as to be capable of transverse movement controlled
by springs, substantially as described.
3. A locomotive or other motor frame having the coupled wheels on the one side
driven independently of those on the other side, substantially as described.
Dated this 14th dor of A vs 1802
ABEL & IMRAY,
Agents for Applicant.