Improvements in and relating to Brakes for Railway and Tramway Vehicles.
Year: 1892

page_text: Date of Application, 26th May, 1892
Complete Specification Left, 25th Mar., 1893-Accepted, 26th May, 1893
PROVISIONAL SPECIFICATION.
Improvements in and relating to Brakes for Railway and Tramway
Vehicles.
I, ALEXANDER CAMERON, of 23 Paterson Street, Glasgow, Lanarkshire, Clerk,
do hereby declare the nature of my invention to be as follows:--
This invention comprises the use of a friction brake wheel turning on an
eccentric centre so as to act as a double rolling wedge or cam mounted on the free
end of a forked or other lever carried on an actuating spindle in bearings in the
lower frame of the vehicle, instead of an ordinary brake block. This spindle has
another lever for taking the brake wheel out of action or putting it into action, and
may be mounted on any or all of the wheels of the vehicle, and be actuated by
various combinations of appliances, as by vacuum or pressure air or steam, in
railway passenger trains fitted with fluid pressure arrangements, or by strong electro
magnets in railway or tramway vehicles fitted with electrical power arrangements;
or in railway wagons or trucks be actuated by the springs of the draw rods and
buffers.
In actuating this brake by pneumatic arrangements these would consist of a
small open ended cylinder with single acting piston fitted with a spring or weight
to actuate its rod in one direction, while the vacuum or pressure would act on the
piston in the opposite direction with a greater power than the spring or weight to
keep the brake out of action by its arrangement of levers in connection with this
rod. This rod shuts a valve on the escape pipe of the close end of a liquid
cylinder which has a single acting piston actuated in one direction by a spring on
its rod to raise the piston and bring the lever and its brake wheel into action on
the periphery of the wheel of the vehicle when relieved by the shutting off or
breaking of the vacuum or compressed air pipes; and the moment the brake wheel
or cam began to turn on the surface of the vehicle wheel, the eccentric wedge
action would force down the liquid piston and bring on a gradually increasing
pressure on the brake. The liquid cylinder would preferably have an inverted
siphon pipe to always contain the liquid in it sufficient for its proper action; and
whenever the guard or attendant of the train turns on the pneumatic action to
relieve the brake, he also relieves the valve of the liquid cylinder and takes the
eccentric brake friction wheel out of action again. In some cases the piston rod
of the liquid cylinder might carry the eccentric brake wheel on its outer free forked
end and so bring this direct into action on the carriage wheel without the use of
an intermediate lever, with only the spring acting to keep the brake wheel out of
action, which when released by the pneumatic cylinder would shut the valve of the
liquid cylinder and so bring the pressure resistance for the eccentric brake to act
as before described. Or this may be done by a hand lever or by an electro magnet,
instead of by vacuum or fluid pressure.
The mechanical arrangements and combinations of mechanism for actuating this
new eccentric wheel brake consist in so connecting the draw rods at opposite ends
of the wagon or vehicle to levers on a special cross lever or brake actuating crank
shaft, that this shaft when the draw links were pulled by its connection with the
lever spindle of the brake wheel or wheels would always take it or them out of
action against the power of a light spring or weight which brought them into
action; but when let go would allow the brake lever and spindle to fall and bring
the brake wheel into action and hold it there by a spring catch or pawl, so that
the further running of the carriage wheels would bring the wheel brake more
powerfully into action until the vehicle or train was stopped. The starting of the
train by the draw links would take the resistance links and brake wheels out of

page_text: action. Or a rod or other equivalent would be fitted at the side of each vehicle
to take these resistance links or connections out of action and release the eccentric
brake wheels when the vehicles had to be shunted or driven in the opposite
direction. Another alternative mechanical arrangement for bringing the brakes
into action would consist of a reciprocating rod mounted on a lever on the spindle
of the friction brake wheel, with its free end connected by a link to a crank or
lever on the shaft actuated by the draw links so that as the draw links allowed the
crank and link to turn, it would lower the one end of this rod and raise the other
end until it acted on a friction wheel on one of the axles of the vehicle, the friction
of which would draw this rod and the brake wheel into action on the periphery of
the vehicle wheel and may also cause it to bring the resisting catch into action on
a lever of the friction wheel. In some cases the draw rods need only be connected
to act in one direction on the levers of the crank shaft which actuates the brake
wheel levers, that is only to pull the brakes out of action, while the buffer rods
might be made to keep the brake wheels out of action, or a spring or weight or a
hand crank on the outer ends of this shaft would bring the brakes into action,
in each case without interfering with the action of the draw links.
By another mechanical arrangement the friction brake wheels might be
mounted on one arm of a bellcrank, say the shorter arm while the longer arm
would have an oscillating spring pressing or resisting lever mounted on it which
would fall in by the power of its spring under a short swivelling removing detent
or lever mounted on the end of the cross crank or lever shaft and hold the friction
wheel into action on the periphery of the vehicle wheel except when this lever
shaft was turned by the draw links to take the brake wheel out of action, and
the detent pushed the spring resisting lever out of action, which would release the
, bellcrank and friction wheel, while the balanced action of the same would turn
the brake wheel to its non-acting smallest periphery position. This balancing of
the friction wheel on its lever might be effected either by a spring or counter-
weight.
In applying these improvements to lorries or other road vehicles the friction
wheels would be mounted to be put into operation by a hand lever on the
peripheries of one or more of the wheels of the vehicles, as when going down hill.
Instead of mounting this new or improved eccentric or cam brake wheel to
act on the periphery of the ordinary running wheels of the railway carriages or
other vehicles they may be mounted to act on a special friction wheel mounted for
the purpose on any of the axles of the vehicle when the running wheels are
keyed on the axles.
Dated 24th May 1905
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Brakes for Railway and Tramway
Vehicles.
I, ALEXANDER CAMERON, of 23 Paterson Street, Glasgow, Lanarkshire,
Clerk, do hereby declare the nature of my invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement in writing, reference being had to the accompanying drawings,
that is to say :-
This invention comprises the use of a friction brake wheel, turning on a movable
eccentric centre (instead of an ordinary brake block), so as to act as a double
rolling wedge or cam in either direction on the periphery of the wheel of the
vehicle. This eccentric wheel is mounted on the free end of a forked or other
lever, carried on an actuating spindle in bearings, on the lower frame of the vehicle.
The spindle has another lever secured to it, for taking the brake wheel out of
action, or putting it into action and may be mounted on any or all of the wheels of

page_text: the vehicle, and be actuated automatically by various combinations of appliances,
as by vacuum or pressure air or steam, in railway passenger trains fitted with fluid
pressure arrangements, or by strong electro magnets in railway or tramway vehicles
fitted with electrical power arrangements; or in railway wagons or trucks be
actuated by the springs of the draw rods and buffers or by hand levers, all as
hereinafter described.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended an explanatory sheet of drawings in which the same reference letters are
used to indicate corresponding parts in all the figures where shown.
Figures 1 and 2 show an irregular sectional elevation and a corresponding inverted
plan view of a railway goods truck T, broken away at a part, between the wheels W.
Figure 3 shows an elevation, broken away, from the opposite side of one end of
the truck T, to show the mechanical disengaging and locking mechanism more
clearly than can be seen in Figures 1 and 2, all illustrative of two arrangements
and combinations of my improvements as suitable for automatically actuating the
improved eccentric brake wheel A to put it into or out of action by fluid pressure,
as shown on the right hand end of Figures 1 and 2, or mechanically by the draw
links, as shown on the left hand end of these figures, and in Figure 3.
Figures 4 to 9 show detail sectional views of various modified arrangements of
the brake actuating mechanism to be hereinafter described.
Referring to Figures 1 and 2 of these drawings:-In actuating this eccentric
brake A by pneumatic arrangements as shown to the right of these figures, these
would consist of a small open ended bored cylinder a, with single acting piston a¹
fitted with a helical spring a2, (but it might be a weight) to actuate its rod a³ in
of the
one direction, while the vacuum or negative pressure in the air pipes
vehicle would act on the piston a' in the opposite direction and with a greater
power than the spring, that is the atmospheric pressure would act on the piston a'
from the open end of the cylinder a in the opposite direction to the spring a² to
keep the brake wheel A out of action by the lever ', 2. This lever 2 is
fulcrumed on a strong stud bracket on oneiside of the vehicle T, and the arm ²
acts on the arm 12 of the brake A to take it out of action when the pressure air
acts on the piston a. And to bring the brake A into action the rod a³ shuts a
valve a preferably a piston valve on the inlet and escape pipe c" of the close end
of a liquid cylinder c. This cylinder c has a single acting piston e' actuated in one
direction by a strong spring ² on its rod e³ working in guides c on the sides of the
truck T to raise the piston c' and raise the lever B2 and bring its brake wheel A
into action on the periphery of the wheel W, of the vehicle by its lever B when
relieved by the shutting off of the vacuum in the pipe b, or by the breakage or
leakage of the air pressure pipes when compressed air is used. The moment the
brake wheel or cam A was brought into action and began to turn on the surface
of the vehicle wheel W in either direction, the eccentric wedge action would force
down the liquid piston cl, and bring on a gradual increasing pressure on the brake A,
the valve a being then shut. The axle A¹ of the brake wheel A is mounted loose
in the end of its lever B, and has mounted on its one end a short crank A2
with antifriction pulley on it, and has the lever end of a spring A³ acting on
its inner side, the spring being shown as a spiral spring mounted round the
spindle B, the other arm A, of the spring A³, being secured to the frame T of
When the brake wheel A is
the truck, as seen more particularly in Figure 2.
released from its action on the wheel W, this lever and spring A2, A3, always
brings the smaller radii of the brake wheel A. towards the circumference of the
wheel W, so that when put into 'action it may have a circumferential rolling wedge
brake action in whichever direction the wheel W may be running. The liquid
cylinder c would preferably have an inverted siphon pipe c" to always contain the
liquid which is fed from the cistern C, sufficient for its proper action, to give
resistance to the eccentric action of the brake when the valve a¹ is closed; and
whenever the guard or attendant of the train turns on the pneumatic action to

page_text: relieve the brake, the valve of the liquid cylinder is opened by the raising of
the piston a and the eccentric brake friction wheel A is taken out of action against
the force of the spring 2. The eccentric brake wheel A, would by preference be
covered with a circumferential band or surface of india rubber or other equivalent
and which may be protected on the outside by a chain of metal plates. In some
cases, as shown in sectional elevation in Figure 4, the piston rod c³ of the liquid
cylinder e might carry the eccentric brake wheel A, by its axis A', on its outer
free forked end B, working in a guide slide bracket c', and so bring this direct into
action on the carriage wheel W, without the use of intermediate levers B, B2;
and by the vacuum acting on the piston a³ against the power of the spring a²
keep the brake wheel A out of action, through the lever 2 while the relieving
of the vacuum would bring the brake wheel A. again into action to turn in either
direction, all as herein before described in reference to the former figures, and
lettered to correspond the oil or other liquid in the pipe el forming a resistance to
the action of the brake wheel A. The hand lever allows the attendant to either
take off or put on the brake A, by hand as before described.
The mechanical arrangements and combinations of mechanism for actuating this
new eccentric acting wheel brake A, A', through the ordinary hook and spring draw
rods D at opposite ends of the wagon or vehicle, are shown on the left hand side_of
Figures 1 and 2 and Figure 3. This arrangement consists of a joint block D',
secured to each rod D, and jointed to one end of a connecting rod D" through a
slotted joint at the other end to a crank D2 secured on the centre of a cross shaft D³
carried in journal bearings D, attached to the lower frames T of the truck. As
seen particularly in Figure 3, this shaft D³ has on its one end outside the frame a
duplex armed catch lever d, d', secured on it for actuating a lever B³ on the
spindle B of the eccentric brake wheel A, equivalent to the lever B2 in the
pneumatic arrangement for putting the brake ▲ into or taking it out of action.
The lever d' is formed as a slotted lever working between adjustable screw collars (
on a link attached to the lever B³, to either raise or lower it as the draw rods D
are pulled by their hooks or drawn in by their springs 111. While the catch
arm d of this lever takes into a locking recessed block d³, secured on the outer end
of the lever B³, when the lever B' is lowered to bring the brake A into action, and
so hold the lever to give a resistance to the action of the brake wheel; and vice versa
disengage the catch d and release the lever B³ when the draw bars are pulled by
their hooks to start the train, a spring B being fitted on the lever B of the brake
wheel A to assist in bringing this wheel into action on the periphery of the wheel W
when the catch is released and the draw links ceased to act, and thus stop the train.
The other end of the shaft D³ has a hand lever D₁ on it for releasing the brake
wheel A, and its catch mechanism independent of the draw rods, and this lever
might be connected as shown in Figure 5 by a connecting rod D³, and hand
lever D, at any other part of the vehicle, or the locomotive when fitted on it.
in Figure 3 an arrangement is shown by which a buffer T¹ is made to actuate a
spring rod E, E¹, working in parallel guides E on the side of the vehicle, the
spring E always keeping the outer end of this rod E against the inner head of the
buffer T¹, while the other end is jointed to the lower arm E2 of a lever E², E³,
fulcrumed on a fixed centre at E. This lever works over the angled or curved
end of a lever B, secured on the axle B₁ of the brake wheel A, and a weighted
catch lever e is fulcrumed on the lower end of the lever E2, so that when the
buffer T comes into action it pushes the rod E against the power of the spring E',
and causes the lever E2 to act on the angular end e¹ of and depress the lever B4 and
thus take the brake wheel A out of action. While the catch lever e passes a stop
pin e on the angled end e¹ of the lever B, and so keeps the brake wheel out of
action while the train is being backed until the lever B is brought down by the
draw link through the spindle D³ and crank d, d'. Figure 6 shows an elevation of
a mechanical arrangement of spring stop lever for preventing the brake wheel A
acting when the train is backing, instead of using the buffer spring rod E and
levers E2, B, described in reference to Figure 3 for that purpose. And this
But

page_text: consists in mounting a spring stop lever F, F, on a fixed stud F", behind the catch
lever d, so that the spring F1 comes forward under the outer end of the lever B³,
and prevents the brake wheel A coming into action on the wheel W until the
spindle D³ is turned by the connecting rod D", sufficient for the catch lever d to
take the stop lever F out of action. Or the spindle D³ may be turned to do this by
hand by any of the arrangements of hand levers D or D³ hereinbefore described
and so put the stop lever F into or out of action with the lever B³ to keep the
brake wheel A out of or permit it to come into automatic action with the wheel W
of the vehicle. In coming into action the travelling of the train and turning of the
wheel W turns the eccentric brake wheel A, so as to raise the lever B³, when the
spring catch lever F comes under its free end and keeps the brake wheel A out of
action when the train is being backed. Figures 7 and 8 show sectional elevations
of arrangements of liquid cylinder and piston c, c, with its supply cistern C in
which the brake levers B and B2, are actuated by the spring 2 on the piston rod e³
to bring the brake wheel A. always into action on the periphery of the carriage
wheel W, all so far substantially the same and lettered to correspond with the
arrangement shown on the right hand side of Figures 1 and 2. But as shown in
Figure 7, the brake wheel A. is taken out of action by the lever 61, 62, in this case
mounted on a spindle 6, and actuated by hand (instead of by the pneumatic or
vacuum arrangements described in reference to Figures 1 and 2) through a lever 1,3
attached by a connecting rod D to a hand lever De mounted on any part of
the vehicle T, so that in pulling the lever and rod D, D³, the lever acting on
the lever B2 takes the brake A out of action against the spring 2 at the same time
opening the valve a' by its lever to allow the liquid to escape from the inner end
of the cylinder c, and so act otherwise in an equivalent manner to take off or put
on the brake action, the liquid forming a resistance to the brake action as in the
previous described arrangements. In Figure 8 an arrangement is shown in which
the draw rods D are made to take the brakes A out of action, (instead of the hand
lever D,) by jointing the slotted end of the connecting rod D" to a vertical lever f
on a spindle which through a horizontal acting lever f¹ is connected by a link f
to the arm of the lever b', 2, and when the draw bar D is pulled to start the
train, this lever 6' is pushed up, opens the valve a', and pushes down the arm 2
which depresses the lever B2, and so takes the brake wheel A out of action against
the power of the spring c², which brings it into action, and so act by the draw
bar D to automatically take the brake A out of action or put same into action as
required. Figure 9 shows a sectional elevation of an arrangement in which when
the draw rods are pulled in by their springs, the brake wheel A, may be kept out
of action. This consists of a cylinder a, and plunger or piston al working in it,
actuated by compressed air or steam within the pipe b, the head or rod of the
piston a³, in its upward movement raising the lever B³ to keep the brake wheel
out of action. Vacuum may be used instead of compressed air or steam by
inverting the arrangement and placing it over the lever B³, with a catch at the
outer end of the piston a¹ extending under the lever so as to keep it up. The lever
may also be kept up by an electro-magnet. Although helical springs have been
shown in all these arrangements for actuating the rods and levers, it is to be
understood that any other forms of suitable equivalent acting springs might be
used to move their respective parts.
Instead of mounting this new or improved eccentric or cam brake wheel to act
on the periphery of the ordinary running wheels of the railway carriages or other
vehicles they may be mounted to act on a special friction wheel mounted for the
purpose on any of the axles of the vehicle when the running wheels are keyed on
the axles.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
First. The arrangement and use on railway and tramway, vehicles, of a friction

page_text: brake wheel, turning on an eccentric centre and carried on lever or equivalent
mechanism to act as a brake in either direction on the circunferential surface of
the travelling or brake wheel of the vehicle, substantially as herein described in
reference to and by way of application shown in the accompanying drawings.
Second. In railway and tramway, vehicles, the fitting and use on the vehicle
wheels of an eccentric acting friction brake wheel or wheels carried by lever or
equivalent mechanism in combination with fluid pressure or vacuum and the other
arrangements herein described and shown for maintaining the brake wheel out of
action, and liberating it either automatically or by hand to put same into action by
spring and lever mechanism, substantially as herein described in reference to the
accompanying drawings.
Third. In railway and tramway, vehicles the fitting and use on the vehicle
wheels of an eccentric acting friction brake wheel or wheels carried by lever or
equivalent mechanism in combination with a liquid cylinder and piston with valve
for admitting the liquid and closing it in to act as a resistance against the eccentric
action of the brake wheel in either direction, substantially as herein described in
reference to and by way of application shown in the accompanying drawings.
Fourth. In railway and tramway vehicles the fitting and use on the vehicle
wheels of an eccentric acting friction brake wheel or wheels carried by lever or
equivalent mechanism in combination with a mechanical arrangement of cross shaft
and levers for positively putting the brake wheel into action, with a locking
resistance against the eccentric action of the brake wheel in either direction, and
taking it out of action automatically by the draw links, substantially as herein
described particularly in reference to the left hand side of Figures 1 and 2, and in
Figure 3 and in the modified forms in Figures 5 and 6 of the accompanying
drawings.
Dated the 24th March 1893.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.