IMPROVEMENTS IN RAILWAY BRAKES, PARTLY APPLICABLE TO OTHER PURPOSES."
Year: 1880

page_text: LETTERS PATENT to William Timbrill Clark, of Crick, near Rugby, in the
County of Warwick, and William Henry Ashwell, of Argyll House, the Oval,
Bedford, in the County of Bedford, for an Invention of "IMPROVEMENTS IN
RAILWAY BRAKES, PARTLY APPLICABLE TO OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said William Timbrill Clark
and William Henry Ashwell at the Office of the Commissioners of Patents on
the 28th June 1880.
WILLIAM TIMBRILL CLARK, of Crick, near Rugby, in the County of Warwick,
and WILLIAM HENRY ASHWELL, of Argyll House, the Oval, Bedford, in the
County of Bedford. "IMPROVEMENTS IN RAILWAY BRAKES, PARTLY APPLICABLE
TO OTHER PURPOSES."
Our Invention of improvements in railway brakes has reference to automatic
apparatus that may be operated by compressed air or other fluid, or by vacuum.
Our Invention may be carried out under different arrangements, according to
requirement.
We construct apparatus that will operate either by air under compression or
vaccuum, so that vehicles fitted with it may be connected at convenience either with
an engine fitted with compressing apparatus or with an engine fitted with
exhausting apparatus.
Apparatus according to our Invention may also be so arranged that the same
apparatus may be used either as a hydraulic, a compressed air, or a vacuum brake.
Our Invention moreover includes modifications of apparatus designed respectively
to act as compressed air (or other fluid) brakes and as vacuum brakes.
In one arrangement of apparatus according to our Invention in a cylinder we
will call the brake cylinder placed under the vehicle works a piston, coupled either
directly or by suitable gear to the brake blocks, a small auxiliary cylinder (with
check valve) and piston, or a spring contrivance is or may be provided to
compensate for the area of the piston rod when vacuum is employed. To each end
of the brake cylinder is connected a valve box. Each of these valve boxes contains.
two valves, one pair coupled with their faces towards one another, the other pair
[Prins 1471

page_text: coupled contrariwise, and each pair connected to a flexible diaphragm, open at one
side to the atmosphere, and at the opposite side in communication with the train
pipe. Each valve chamber is connected at one end with the receiver or accumulator,
and at the centre with the brake cylinder behind the piston. Also connected to the
receiver and train pipe is an. automatic reversible check valve, that is to say, a
chamber with two seats facing each other and in which works a hollow valve,
within which two or more other valves work back to back. The hollow valve is
connected to a flexible diaphragm open at one side to the atmosphere and at the
other to the train pipe.
With apparatus as just described, assuming compressed air to be the actuating 1
medium, so long as the requisite pressure is maintained in the train pipe, compressed
air from the receiver will act with equal force at the two opposite sides of the brake
piston; but should the pressure in the train pipe be reduced by the opening of a valve
or by leakage (accidental or otherwise), the valves will be reversed or moved over so
as to open one side of the brake piston to the atmosphere, thus causing the brake
blocks to be forthwith applied to the wheels by the action of the compressed air at
the other side of the piston. If vacuum be employed, then so long as the pressure
in the train pipe remains sufficiently below that due to the ordinary atmosphere,
there will be in the brake cylinder at both sides of the piston a partial vacuum ;
but on the opening of a valve or communication between the outer air, and the
train pipe being established by design or accidental disconnection or fracture, the
valves will be so operated as to admit air at the atmospheric pressure to one side of
the piston, thus causing the brake blocks to be applied to the wheels.
'
Apparatus as described may be constructed in various forms; and in lieu of one
piston the brake cylinder may contain two, the connections with the double valve
chambers being appropriately arranged. To keep the cup leathers tight we provide
them with spring linings or backings, consisting of discs or pieces of sheet steel, or
other suitable metal with serrated edges, the teeth or pointed projections being.
bent round or turned up to a suitable angle to bear against and follow up the
leather as it wears.
To retain vacuum or compressed air in the train pipe during shunting operations
we provide a valve chamber, having in its lower part two seats facing each other,
a flexible diaphragm above, and between the two seats a valve with a stalk,
passing up through and attached to the centre of the diaphragm. When the valve
is held midway between the two seats there is a clear passage for either air or
vacuum, but when released it closes against one or other of the seats. The flexible
pipe connection to the next vehicle is coupled to the central portion of the valve
chamber.
In another arrangement of our apparatus, a cylinder contains a piston fitted with
two cup leathers back to back, and there are two cup leathers similarly arranged
on the piston rod. Round the centre of the piston's periphery is a groove, in
connection with which on one side of the piston is a small valve, so that when
vacuum is employed it is formed round the groove, thus preventing any strain being
put on the leather which is designed to serve when compressed air or hydraulic
power is employed. As the leathers in pneumatic cylinders become hard and dry,
we, in order to lubricate them, provide a hole right through the piston rod and
piston, so that lubricant may be forced through the piston rod and into the top
part of the cylinder between the two cup leathers, thus falling away on each side of
the cylinder and lubricating the leathers, a small hole with screwed plug being
provided between the two leathers on the piston rod for the same purpose, and also
a small valve in connection with the centres of the two leathers, so as to act when
the brake is worked by vacuum only. Or in lieu of the above we provide a twisted
bar in the end of the cylinder, and extending into the piston rod; or we fix a pawl
either to the cylinder cover or piston so as to work round a ratchet path which in
the one case is on the piston, and in the other case is on the cylinder cover, thus
causing the piston to make a partial revolution each time the brake is applied, and
at the same time carrying lubricant from the bottom of the cylinder round with it.
5

page_text: This cylinder can be made longer and be provided with two pistons, as the one
before described, thus pulling in both directions.
When the brake is worked by vacuum, a small auxiliary cylinder or body of
leather, india rubber, or prepared cloth is provided at any convenient position, to
compensate for the size of the piston rod and keep the brake off.
an
Along the carriage is carried a pipe or pipes, in connection with which
automatic reversible valve or valves. Such valve or valves connects or connect
directly with the receiver; back from the receiver is another pipe or pipes
connecting two sets of double valves, one set for relieving the pressure from
the brake cylinder to the atmosphere when worked by compressed air, and
the other set for admitting the atmosphere when the apparatus is worked by
vacuum. These valves are connected to two small diaphragms which are in
connection with the train pipe, one acting with compressed air, while the other is.
actuated by vacuum, but when either compressed. air or vacuum is maintained in
only one end of the cylinder.
Brakes capable of reversible motion may be constructed with three way cocks
with separate valves and chambers in connection with the receiver and the
cylinder or its equivalent. Also the brake levers can be worked by the use in lieu
of a cylinder and piston or pistons of a collapsible vessel, with a piston placed in;
its centre, this allowing the compressed air to act on one side when the brake is in
use by compressed air, and forming a vacuum in the opposite side when worked by
same.
When worked by vacuum in connection with this are two small auxiliary
cylinders or collapsible vessels to connect a larger area, as already described..
Instead of them a balance weight or spring might be substituted. In their
respective turns (that is to say, when the brake is used by compressed air or
vacuum) these auxiliary cylinders or collapsible vessels are singly in connection
with the train pipe or pipes. Connected to the large piston in the centre are
two side rods which are connected at the ends by a crosshead to the brake
levers.
Sliding on the piston pins are four small side rods with long slots, two connected
to each of two cross-heads; these crossheads are fastened one on one end of each of
the small auxiliary cylinders or collapsible vessels, thus allowing the brake to
operate by pressure or by vacuum.
Another feature of our Invention is the automatic taking up of the brake blocks
as they wear. In one arrangement for this purpose the brake blocks are actuated
by two small levers having their fulcra on longitudinal compound rods, one passing
along the inside of each wheel. The longitudinal compound rods are jointed to a
cross-bar which carries a brake block at each of its ends. Each of the longitudinal
compound rods is formed in two lengths, one with a left hand screw thread, the
other with a right hand thread; these ends are connected by a long nut with right
and left handed threads. This nut is made at both ends to form a ratchet pinion,
and when the levers are forced back and the brake blocks opening from the wheels,
pawls on the levers cause the nuts to turn, thus shortening the compound rods, and
other pawls keep the nuts from turning back again.
When the brake cylinder is fixed close under the frame of the carriage, the two
levers are arranged vertically, and their lower. ends are connected by compound.
rods, each made with one part as a ratchet taking into a hollow portion of the
other part, which we will call a sleeve. In the sleeve is a slot or slots in which is
a pawl or pawls, so that when the brake is relieved its proper distance the sleeve
slips over the rack and allows the pawl or pawls to drop into one or two of the
teeth, thus shortening the rods that couple the two levers and drawing the blocks
closer to the wheels. The hangers for the brake blocks are formed with ball and
socket joints to allow for oscillation of the wheels, and are provided with a ratchet
rack to regulate the distance from the wheels.
In some cases we construct the receiver or accumulator in the form of a jacket

page_text: •
.
•
or in lieu of a jacket or
or jackets encircling or surrounding the brake cylinder;
jackets we provide in the end or ends of the brake cylinder an enlargement, recess,
or expansion chamber, or enlargements, recesses, or expansion chambers, in
appropriate communication with the train pipe.
In one arrangement of brake designed to be operated by compressed air, the a
cylinder is fitted with two pistons coupled to the brake blocks, as before described,
the ends of the cylinder being provided with expansion chambers or jackets which
are in communication with the train-pipe, that at one end by an ordinary check-'
valve, so that air may pass in but not out, the other by an automatic valve
arrangement. Behind and between the pistons is a passage communicating with
the valve chamber of the automatic valve arrangement, which comprises two valves
with bevil faces opposite one another; the larger diameters or peripheries of these
valves form piston valves, and are so arranged that there is never a direct passage
past the two valves between their seats and faces. One end of the valve chamber
is in connection with one of the expansion chambers, and the central part of the
valve chamber is, as already stated, connected to the brake cylinder between and
behind the pistons. The valves are connected to a flexible diaphragm, one side
of which is exposed to the train pipe, and the other side is open to the
atmosphere.
This arrangement of apparatus is susceptible of modification, and may be
constructed with only one expansion chamber or jacket and one piston.
In a modification designed to operate by vacuum only, and wherein the cylinder.
contains two pistons coupled to the brake, and has at the ends expansion chambers
or jackets, such as before described, we provide a valvo chamber with two valves
arranged back to back connecting the valve chamber as before to the train pipe and
cylinder, and arranging the check valve in connection with train pipe with its face
in an opposite direction to that in the compressed air arrangement.
Apparatus such as just above referred to may be modified in detail. The
cylinder may contain one piston only, and an ordinary receiver or accumulator may
be used in lieu of the expansion chamber or chambers or jacket or jackets.
The couplings whereby the brake apparatus of one vehicle is connected to that of
another are so constructed that the length of train pipe belonging to each vehicle
will be automatically closed when disconnection is effected. In one arrangement of
coupling for this purpose, one half or part of the coupling is formed with a bend or
knee, and contains a valve arranged at right angles to the valve in the other half
or part, and having a spring tending to close it against its seat. The valve in the
other half or part of the coupling also has a spring and has its axis in line or
parallel with that of the train pipe. Each half or part of the coupling has a nib
and a segment of screw thread or an incline, and one is so arranged to fit in the
other, that when placed one in the other, and turned or brought round with their
respective portions of train pipe in line, the two valves are by suitable inclines or
cam pieces forced from their respective seats, thus establishing through communi-
cation between the two lengths of train pipe.
In another arrangement of coupling there are two chambers, each with a valve
and a spindle so arranged that in the act of coupling the two chambers the valves
are forced open, thus establishing a clear passage. Handles are provided for
screwing together the two chambers.
When the brake is fitted to work by hydraulic as well as other fluid pressures,
the receiver is fitted with a piston so that the pressure will expand the pistons, the
piston being under control of a spring or lever so as to act as an accumulator.
Another part of our Invention has reference to motivo power engines for working
the compressing or exhausting pnmps, and which engines may be used also for
other purposes.
A tappet rod, one end of which projects into the steam cylinder, is at the other
end actuated by the piston of the pump. To an intermediate part of this tappet
rod is fixed an arm or other suitable device, whereby it is connected through a

page_text: suitable rod to the main slide valve which is a hollow piston valve containing two
stationary pistons, one at each end; their rod passes directly through the centre
of the main valve and contains three small ports which are in communication
with passages formed in the main slide valve, which constitutes a distributing
and exhausting valve regulating the supply of steam to each of the small pistons.
In lieu of the arrangement above described a lever may be attached to the tappet
red so as to work the main slide valve, and also a small slide valve distributing
steam on a piston for assisting the main slide valve.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Timbrill Clark and William Henry Ashwell in the Great
Seal Patent Office on the 28th December 1880.
WILLIAM TIMBRILL CLARK, of Crick, near Rugby, in the County of Warwick,
and WILLIAM HENRY ASHWELL, of Argyll House, the Oval, Bedford, in the
County of Bedford. "IMPROVEMENTS IN RAILWAY BRAKES, PARTLY APPLICABLE
TO OTHER PURPOSES."
Our Invention of improvements in railway brakes has reference to automatic
apparatus that may be operated by compressed air or other fluid or by vacuum.
Our Invention may be carried out under different arrangements according to
requirement.
We construct apparatus that will operate either by air under compression or
vacuum, so that vehicles fitted with it may be connected at convenience either
with an engine fitted with compressing apparatus or with an engine fitted with
exhausting apparatus.
Our Invention moreover includes modifications of apparatus, desigued respectively
to act as compressed air brakes and as vacuum brakes.
In one arrangement of apparatus according to our Invention in a cylinder we will
call the brake cylinder, placed under the vehicle, work two pistons, each coupled
either directly or by suitable gear to brake blocks. Two small auxiliary cylinders
(with check valves) and pistons or spring contrivances or collapsible cylinders may
be provided, to compensate for the areas of the piston rods when vacuum is
employed. To each end of the brake cylinder is connected a valve box. Each of
these valve boxes contains two valves, one pair coupled with their faces towards one
another, the other pair coupled contrariwise, and each pair connected to a flexible
diaphragm, open at one side to the atmosphere, and at the opposite side in communi-
cation with the train pipe. Each valve chamber is connected at one end with the
receiver or accumulator, and at the centre with the brake cylinder. Also connected
o the receiver and train pipe is an automatic reversible check valve, that is to say;
chamber with two seats facing each other, and in which works a hollow valve,
within which two or more other valves work back to back. The hollow valve is

page_text: connected to a flexible diaphragm, open at one side to the atmosphere and at the
other to the train pipe.
With apparatus as just described, assuming compressed air to be the actuating
medium, so long as the requisite pressure is maintained in the train pipe, compressed
air from the receiver will act with equal force at the two opposite sides of the
brake pistons; but should the pressure in the train pipe be reduced by the opening
of a valve or by leakage, accidental or otherwise, the valves will be reversed or
moved over so as to open one side of the brake pistons to the atmosphere, thus
causing the brake blocks to be forthwith applied to the wheels by the action of the
compressed air at the other side of the pistons. If vacuum be employed, then so
long as the pressure in the train pipe remains sufficiently below that due to the
ordinary atmosphere, there will be in the brake cylinder at both sides of the pistons
a partial vacuum; but on the opening of a valve or communication between the
outer air and the train pipe being established by design or accidental disconnection
or fracture, the valves will be so operated as to admit air at the atmospheric
pressure to one side of the pistons, thus causing the brake blocks to be applied to
the wheels.
Fig. 1, Sheet 1, of the Drawings is a side elevation of a brake cylinder, together
with its receiver, train pipe, and various valves, arranged so that it can be worked
either by compressed air or by vacuum.
Fig. 2 is an inverted plan of the same; G is the cylinder containing two
pistons FA, FA, which put on the brakes by suitable mechanism described hereinafter
when they are moved towards one another, and take the brakes off when forced
apart. The construction of the apparatus will be clearly understood from the
Drawings and the following explanations of its operation. We will first explain the
operation with compressed air, premising that in the Drawings the valves are
shewn in positions that do not altogether correspond with those that obtain either
When worked
when working with compressed air or when working with vacuum.
by compressed air the action is as follows:-The air enters the receiver 1 through
the reversible check valve A C, already described in outline (and which will be
fully described hereinafter with reference to the detailed views, Figs. 4 and 5,
Sheet 8), and proceeds to the boxes or cases A, A, and B, B, of the automatic
valves FE, and FF, EE. These boxes or cases are divided, each by a flexible
diaphragm (D, D¹), which operates the valves in the case, the lower sides of the
diaphragms being connected by junction pipes 2 and 2ª respectively to the train
pipe 3. Each of the junction pipes contains a double valve, that in 2 being marked
B, C, and that in 2 being marked B¹, C'; these double valves are so arranged that
when working with compressed air such air is admitted by the valve B, and the
atmosphere is excluded by the valve C from the under side of the diaphragm D,
as actually shewn in Fig. 1, Sheet 1, while, contrariwise, compressed air is excluded
from and the atmosphere is admitted to the under side of the diaphragm D¹ by the
valves B, C, respectively, which when working with compressed air assume the
reverse positions to those actually shewn in Fig. 1, Sheet 1, that is to say, B¹ closes
and Copens. The upper sides of both diaphragms are open to the atmosphere
through the ports DD, DD. Air from the receiver passes the valve F, and being
stopped by the valve E (both valves being raised by the diaphragm D, as shewn in
Fig. 1, Sheet 1), turns along the pipe 4 (Fig. 2, Sheet 1, Fig. 2, Sheet 2, and Fig. 3,
Sheet 4) into the cylinder between the pistons. Compressed air likewise passes the
valve FF, and is stopped by the valve E E. It will be seen these valves are
arranged back to back, that is contrariwise to the valves F and E, and it is to be
understood that we are now assuming the valves are not being upheld by compressed
air acting under their diaphragm D₁, but that the latter is in the contrary position
to that actually shewn in Fig. 1, Sheet 1. From the valve case B, B, the air passes
by the pipe 5 to both ends of the cylinder G beyond the travel of the pistons FA, FA
which would be in equilibrium were the areas of their back and front faces equal,
but which are respectively forced outwards by the air pressure exerted on an area
equal to the cross section of the piston rod.

page_text: When the pressure of air is reduced in the train pipe 3 either designedly or
accidentally, the valve AC in the reversible check valve will close automatically,
and simultaneously the diaphragm D will (being no longer sustained by air pressure
below it) be forced downwards, and will draw the valve F on to its seat, cutting
off communication with the receiver, and will open the valve E establishing
communication between that portion of the interior of the cylinder which is
between the pistons and the atmosphere, through the pipe 4, valve box A, A, and
ports D, D, thus allowing the compressed air between the pistons to escape.
The valve box B B is not affected by the change of pressure in this case, and
consequently air flows from the receiver into the ends of the cylinder and forces
the pistons towards one another, thereby drawing the brake blocks against the
wheels.
When the apparatus is actuated by vacuum the operation is as follows:-The
vacuum maintained in the pipe 3 closes the valves B and C¹ and opens the valves C
and B¹ in the junction pipes. The positions of the valves E, F, and E E, F F, are
the same as in the former case, the pair E, F, being supported by the pressure of
the atmosphere on the valve E, and the pair EE, FF, held down by the pressure
of the atmosphere on the diaphragm D'. The centre of the cylinder is connected
to the receiver through the valve case A A, and the cylinder ends are connected to
the receiver through the valve case B B.
When air is admitted to the train pipo to bring the brake into action the
reversible check valve automatically closes, and at the same time the diaphragm D¹
rises, opening the valve EF and closing the valve FF, thereby establishing.
communication between the ends of the cylinder and the atmosphere through the
pipe 5, valve E E, and ports D D. Atmospheric air rushing in through the passage
indicated will force the pistons together and put on the brakes.
When working by vacuum it is requisite to compensate for the area of the piston
rods, thus exposing a greater area to keep the blocks off the wheels, and thereforo.
two additional cylinders or collapsible vessels (6 and 7) are provided, each coupled
to the piston rod of one of the pistons FA at one end and at the other end to a fixed
stay. These collapsible vessels are attached by a coupling containing a double
valve (Fig. 4, Sheet 2) to a branch from the train pipe; the valves are so arranged
that when the system is worked by compressed air the valve A' is held down on
its seat and the valve B allows free communication between the interior of the
collapsible vessel and the atmosphere; on the other hand when there is a vacuum
in the train pipe the atmospheric pressure closes the valve B and opens the
valve A¹.
Fig. 1, Sheet is a side elevation shewing our compound brake system as
applied to a railway vehicle, in which G is the cylinder, AC the automatic check
valve, and 8, 8, are brake blocks.
Fig. 2 is a plan of the same.
Fig. 3 is a longitudinal section of the brake cylinder G with its pistons FA
which are shewn with packing leathers 9 and spring linings or backings 10 such as
hereinafter described with reference to Figs. 5 and 6, Sheet 4.
Apparatus such as hereinabove described with reference to Sheet 1 of the
Drawings may be modified in detail and arrangement without departure from tho
essential characteristics of our Invention, thus, for example, in lieu of two pistons
obviously the brake cylinder may contain one only, the connections with the double
valve chambers being appropriately arranged in a manner that will be apparent.
without further description.
Fig. 4, Sheet 8, is a vertical sectional elevation of the automatic reversible check
valve mentioned above, and Fig. 5 (Sheet 8) is a transverse section of the same in
line Y, Z, of Fig. 4. The valve is shewn in these Figures in an inverted position to
that in which it is shewn in Fig. 1, Sheet 1.
1
The inlet A is connected to the train pipe and the outlet B to the receiver.
When the compound brake system is being worked by compressed air, such air
entering at A, forces outward the diaphragm D which carries with it the piston,

page_text: .
valve E until that valve comes in contact with the valve seat G. Air from C
passes through ports or passages M, M, (formed in valve E) into the cavity E¹ of the
valve E, and after forcing the interior valve N from its scat P passes through the
ports H, H, and between the faces of E and F to the receiver through the outlet B.
When the pressure is reduced in the train pipe to put on the brakes the valve N
rises on to the seat P and cuts the communication between the train pipe and the
receiver.
If the system is being worked by vacuum the diaphragm is depressed as shewn,
and the piston valve forced on to the lower seat F F. Communication between
the chamber C and the receiver then obtains, as actually shewn in Fig. 4, Sheet 8,
that is to say, between the faces G and E, through the ports HH, and between the
valve K and its seat L. On the diminution of the vacuum the valve K is closed
by the pressure of the air entering the chamber C.
The two internal valves N and K have a constant tendency given to them
towards their respective seats by the spiral spring 11.
To retain vacuum or compressed air in the train pipe during shunting operations
we provide a valve chamber having in its lower part two seats facing each other, a
flexible diaphragm above, and between the two seats a valve with a stalk passing
up through and attached to the centre of the diaphragın. When the valve is held
midway between the two seats there is a clear passage for either air or vacuum,
but when released it closes against one or other of the seats. The flexible pipe
connection to the next vehicle is coupled to the central portion of the valve
chamber.
Fig. 1, Sheet 8, is a section of a reversible valve fixed at each end of each carriage
to maintain the brake apparatus, whether worked by compressed air or vacuum out
of action when the vehicle is disconnected from the train during shunting
operations.
Fig. 2 is a side elevation, and Fig. 3 a part plan of the same.
Figs. 2a and 2b are detailed views.
The orifice A is for the attachment of the flexible hose pipe, and the orifice B for
the attachment of the permanent train pipe.
When the brake is worked by compressed air the pressure in the chamber C
raises or tends to raise the diaphragm D, and with it the valve spindle E and
valve H. If the lever F (Fig. 2a) be released from the central notch of the catch g
(Fig. 2b) the valve will rise against the seat L and seal the train pipe, so that the
flexible hose pipes may be disconnected without the air escaping from the cylinder,
receiver, train pipe, etc.
When the break is worked by vacuum the atmospheric pressure on the
diaphragm D depresses the valve on to the seat K as soon as the lever is
released.
In some cases in apparatus according to our Invention we construct the receiver
or accumulator in the form of a jacket or jackets encircling or surrounding the
break cylinder. Or, in lieu of a jacket or jackets we provide in the end or ends of
the brake cylinder an enlargement, recess, or expansion chamber, or enlargements,
recesses, or expansion chambers in appropriate communication with the train pipe.
In one arrangement of brake designed to be operated by compressed air the
cylinder is fitted with two pistons coupled to the break blocks, as before described,
the ends of the cylinder being provided with expansion chambers or jackets which
are in communication with the train pipe, that at one end by an ordinary check
valve so that air may pass in but not out, the other by an automatic valve
arrangement. Behind and between the pistons is a passage communicating with
the valve, chamber of the automatic valve arrangement which comprises two valves
with bevil faces opposite one another; the larger diameters or peripheries of these
valves form piston valves, and are so arranged that there is never a direct passage
past the two valves between their seats and faces; one end of the valve chamber is
in connection with one of the expansion chambers and the central part of the valve
chamber is, as already stated, connected to the brake cylinder between and behind

page_text: the pistons. The valves are connected to a flexible diaphragm, one side of which is
exposed to the train-pipe and the other side is open to the atmosphere.
Fig. 1, Sheet 3, is a longitudinal sectional elevation of apparatus arranged to be
worked by compressed air only, and which is constructed with recesses in the
cylinder ends as just above described. In this case the pressure is maintained on
both sides of the pistons when the brake is off, tho ends of the cylinder being
prolonged beyond the travel of the pistons so that the recesses may form receivers
for the compressed air.
The compressed air from the train-pipe A passes the valve B, enters the end C of
the cylinder, proceeds by the passage D to the end E, and goes thence past the
valve G (which is upheld by the diaphragm M) through the pipe or passage 4 to
the centre K of the cylinder. There acting upon the larger areas of the pistons it
pushes them apart and towards the cylinder ends, and takes off the brakes. "When
the pressure is reduced in the train pipe A the check valve B closes, and
simultaneously the diaphragm M draws down the valves G and N, cutting off all
communication between the ends and centre of the cylinder and connecting the
centre to the atmosphere through the pipe or passage H, valve N, and_port O.
The expansion of the air imprisoned in the recessed ends or receivers E and C
forces the pistons towards one another and puts on the brakes.
A general arrangement on this plan is shewn in Sheet 4, together with a section
to an enlarged scale of the diaphragm valve.
The arrangement of apparatus just above described may obviously be modified
by arranging it with only one expansion chamber in the cylinder and one piston.
In a modification designed to operate by vacuum only, and wherein the cylinder
contains two pistons coupled to the brake, and has at the ends expansion chambers.
or jackets W, such as before described, we provide a valve chamber with two valves
arranged back to back, connecting the valve chamber as before to the train pipe
and cylinder, and arranging the check valve in connection with train-pipe with its
face in an opposite direction to that in the compressed air arrangement.
Fig. 2, Sheet 3, shews such arrangement in longitudinal sectional elevation.
In this case the vacuum is maintained on both sides of the pistons when the
brake is off, the ends of the cylinder being prolonged beyond the travel of the
pistons to form the vacuum chambers. This arrangement is similar to the com-
pressed air arrangement last previously described, except that the valves and valve
seats are inverted. The effect of the vacuum in the train pipe A¹ is to cause the
air acting on the diaphragm D¹ to force it down, closing the valve C¹ and opening
the valve D'. The air between the pistons is drawn through the pipe H', and
proceeds, together with air from the chamber F', along the passage G' into the
chamber F, and thence past the check valve E¹ vid the train pipe to the
exhausting apparatus. When the vacuum is diminished in the train-pipe the
valves E' and D¹ are closed isolating the cylinder ends and a communication between.
the central portion K¹ of the cylinder, and the atmosphere is established along the
pipe or passage H¹, past the valve O, and through the port B¹. The pressure of
the air then forces the pistons further apart and applies the brakes.
A general arrangement shewing the application of this plan is shown in Sheet 5,
together with a section to an enlarged scale of the diaphragm valve.
Apparatus such as just above referred to may be modified in detail. An ordinary.
receiver or accumulator may be used in lieu of the expansion chamber or chambers'
or jacket or jackets.
.
Fig. 3, Sheet 3, is a side elevation partly in section of such a modification as
arranged to work with compressed air admitted on one side only of the pistons.
The diaphragm valve has two pipes opening into it, one between and one above
the valves K and C (see Fig. 4, Sheet 6). One pipe G connects the receiver to the
valve box, and another pipe N connects the valve box to the centre of the cylinder..
The compressed air raises the valves D and K, and closes the valve C, thereby
filling the receiver E and opening the space between the pistons to the atmosphere
through the port M. When the air pressure is reduced in the train [pipe the check:

page_text: valve D closes, and the diaphragm B is forced down, closing the valve K and
opening the valve C, thereby establishing a communication from the receiver E
along the pipe G, past the valve C, and through the pipe N into the central part
of the cylinder, where the compressed air from the receiver acts upon the pistons,
forcing them apart, and applying the brakes. The brakes are taken off by a
spring fixed in any suitable position to thrust the pistons back after the air is
released from the centre of the cylinder, this being done by the pressure being
maintained in train pipe again.
A general arrangement shewing the application of the above plan is given on
Sheet 6.
Fig. 4, Sheet 3, is a side elevation partly in section of apparatus arranged to
work with vacuum admitted on one side only of the pistons. This arrangement is
similar to the pressure one last described, but with the valves inverted. The air
acting in opposition to the vacuum opens the valves D' and M' and closes the
valve C. When the vacuum is diminished in the train pipe the valves D¹ and M¹
close and C¹ opens, connecting the receiver to the centre of cylinder, whereupon
the atmosphere acting on the pistons through the holes P, P, in the cylinder covers
forces the pistons towards each other and applies the brakes. To relieve the brake
a vacuum is created in the train pipe, which will cause the valves to move over,
and thus form a direct communication with the centre of the cylinder and the
atmosphere, a spring being used in this case to thrust the pistons outwards, as
shewn.
A general arrangement illustrating the application of the above is given on
Sheet 7.
One feature of our Invention is the automatic taking up of the brake blocks as
they wear. In one arrangement for this purpose the brake blocks are actuated by
two levers having their fulcra on the carriage frame. These two levers are
arranged vertically, and their lower ends are connected by compound rods, each
made with one part as a ratchet taking into a hollow portion of the other part,
which we will call a sleeve. In the sleeve is a slot (or slots), in which is a pawl
(or pawls), so that when the brake is relieved its proper distance the sleeve slips
over the rack and allows the pawl (or pawls) to drop into one or two of the teeth,
thus shortening the rods that couple the two levers, and drawing the blocks closer
to the wheels. The hangers for the brake blocks are formed with loose joints to
allow for oscillation of the wheels, and are provided with a ratchet rack to regulate
the distance from the wheels.
Fig. 1, Sheet 4, shews in side elevation a general arrangement comprising the
compressed air brake already described with reference to Fig. 1, Sheet 3.
Fig. 2 is a plan of the same.
G is the cylinder; B, B, are the piston rods; C, C, C, C, the brake blocks;
D, D, hangers; E, E', E, E¹, compressed coupling rods. The compound coupling
rods are made each in two parts, and are arranged to automatically adjust
themselves as the brake blocks wear. The part E has ratchet teeth, which are
engaged by an internal pawl c in the sleeve E¹, so that when the brake is relieved
beyond its proper distance the sleeve E¹ slips over the rack to the extent of one or
two teeth, and is prevented from returning by the pawl c, whereby the compound
rod is permanently shortened.
Fig. 3, Sheet 4, is a sectional elevation to an enlarged scale of the flexible
diaphragm valve described with reference to Fig. 1, Sheet 3.
Fig. 4, Sheet 4, is a sectional elevation of the compressed air cylinder described
with reference to Fig. 1, Sheet 3.
Fig. 5 (Sheet 4) is a front elevation, and Fig. 6 a vertical section of the spring
lining or backing used for keeping the piston cup leathers tightly against the
cylinders: As seen in Fig. 4 the serrated edge of the spring plate e forces the cup
leather & against the cylinder, the whole being retained in position by the junk
ring f.

page_text: Fig. 1, Sheet 5, is a side elevation of the general arrangement of the vacuum
brake as already described with reference to Fig. 2, Sheet 3.
Fig. 2 is a plan of the same. G is the cylinder; B, B, are the piston rods;
D, D, the hangers; C, C, the brake blocks. The action of the compound coupling
rods E, E¹, E, E¹, is enforced in this arrangement by the toothed segments F, F,
which limit the throw of the hangers to which they are attached to the length of
one tooth, and consequently oblige the toothed bar E to slide into the sleeve E',
when in consequence of wear the throw of the brake blocks exceeds a given
amount.
Fig. 3, Sheet 5, is a section to an enlarged scale of the flexible diaphragm valve,
and Fig. 4 a longitudinal sectional elevation of the brake cylinder already described
with reference to Fig. 2, Sheet 3.
Fig. 1, Sheet 6, is a side elevation of a general arrangement of compressed air
brake in which the air is admitted to the centre of the cylinder only to apply the
brakes, as already described with reference to Fig. 3, Sheet 3.
Fig. 2 is a plan of the same.
Fig. 3 is a section to an enlarged scale of the flexible diaphragm valve of the
same.
Fig. 4 is a longitudinal sectional elevation of the brake cylinder of the same.
Fig. 1, Sheet 7, is a side elevation of a general arrangement of vacuum brake
in which the vacuum is admitted to the centre of the cylinder only to apply the
brakes, as already described with reference to Fig. 4, Sheet 3.
Fig. 2 is a plan of the same.
Fig. 3 is a section to an enlarged scale of the flexible diaphragm valve of the
same.
Fig. 4 is a longitudinal sectional elevation of the brake cylinder of the same.
We so construct the couplings, whereby the brake apparatus of one vehicle is
connected to that of another, that the length of train pipe belonging to each
vehicle will be automatically closed when disconnection is effected. In one
arrangement of coupling for this purpose one half or part of the coupling is formed
with a bend or knee, and contains a valve arranged at right angle to the valve in
the other half or part, and having a spring tending to close it against its seat.
The valve in the other half or part of the coupling also has a spring, and has its
axis in line or parallel with that of the train pipe. Each half or part of the
coupling has a nib and a segment of screw thread or an incline, and one is so
arranged to fit in the other that when placed one in the other and turned or
brought round with their respective portions of train pipe in line the two valves
are by suitable inclines or cam pieces forced from their respective seats, thus
establishing through communication between the two lengths of train pipe.
Fig. 1, Sheet 9, is a longitudinal sectional elevation of a pair of hose pipe
couplings, arranged as just described.
Fig. 2 is a plan of the same; Fig. 3 a section in line C, D, (Fig. 1); Fig. 4 a
section in line A, B, and Fig. 5 a part sectional plan. One part of the coupling
contains a valve E E, the other a valve DD; each valve is forced on to its seat by
a spring. The coupling is effected by first slipping the two parts into each other at
right angles and then bringing them round into a common straight line. Each
half of the coupling has a nib A and a segment of screw thread B, and the one is
so arranged to fit in the other that when placed one in the other and turned round
in line, as described, the two valves EE, DD are by the inclines E and C forced
off their seats, thus establishing communication between the two lengths of train
pipe.
In another arrangement of coupling we use two chambers, each with a valve and
a spindle, so arranged that in the act of coupling the two chambers the valves are.
forced open, thus establishing a clear passage. Handles are provided for screwing
together the two chambers.
Fig 1, Sheet 9, is a longitudinal sectional elevation of this form of coupling, and
Fig. 2a is an elevation of the valves in the same. In making the connection the
•

page_text: square spindle D is first inserted in the square coupling E, and then the two
segments of male thread A A are slipped though segmental openings in the female
thread B B. When the two parts are rotated by the handles to lock the threads
the motion acting through the rock shaft G raises the two valves F and F¹ from
their seats establishing communication between the two train pipes. The valve F 5
is forced against the stop G' and the valve F against the spring K and washer H,
which yield as the valve is forced higher by the further rotation of the parts as the
screw wears.
Another part of our Invention has reference to motive power engines for working
the compressing or exhausting pumps, and which engines may be used also for
other purposes.
A tappet rod, one end of which projects into the steam cylinder, is at the other
end actuated by the piston of the pump. To an intermediate part of this tappet
rod is fixed an arm or other suitable device, whereby it is connected through a
suitable rod to the main slide valve, which is a hollow piston valve containing two
stationary pistons, one at each end; their rod passes directly through the centre of
the main valve and contains three small ports, which are in communication with
passages formed in the main slide valve which constitutes a distributing, and
exhausting valve, regulating the supply of steam to each of the small pistons.
Fig. 1, Sheet 10, is a longitudinal sectional elevation of such an engine.
Fig. 3 is a transverse section in line Y, Z, Fig. 1, and Fig. 4 is an end view with
rods in section. A is a tappet rod which is actuated at one end by the steam
piston and at the other end by the pump piston; B is a vertical arm coupling the
tappet rod A to the valve rod C; E is a hollow compound cylinder and piston
valve which distributes the steam to the steam piston D; E is a double piston
valve fitting in the interior of the compound cylinder and piston valve E, and
abutting at each end against the covers of the valve box.
The action of the valve is as follows:-The piston D strikes the end of the
rod A and pushes it forward; the rod A carries with it the valve rod C and the
valve E, which is connected to the valve rod by a lug or finger Q which engages
with a slot N N in the valve rod. A slight motion of the valve E admits steam
from the steam passage E' into the port F, and at the same time admits steam
through the small port G into the centre of the double piston valve H to force
forward the valve E and complete its stroke. This valve distributes steam to the
piston D and also forms a slide valve for itself at K, the object of the small valve K
being to provide for the admission of steam through the small port G to complete
the stroke of the compound valve E, when the compressing or exhausting
pump is working too slowly, to thrust over the tappet rod D to complete the
stroke of the compound valve E. Provision is made for the lug of this valve to
move in the slot of the rod C at NN. M, M, are two exhaust ports from the
stean cylinder which exhaust into the ends R, R, of the steam chest ; P is the
exhaust port from the small distributing valve.
:
In lieu of the arrangement.above described a lever may be attached to the
tappet rod so as to work the main slide valve, and also a small slide valve
distributing steam on a piston for assisting the main slide valve.
Fig. 5, Sheet 10, is a longitudinal elevation, partly in section, shewing this
modification.
Fig. 6 is a transverse sectional elevation of the same in line Y, Z, of Fig. 5.
A is a tappet rod operated at one end by the steam piston and at the other end
by the pump piston, and jointed at B to a vibrating lever pivotted at C. On the
rod of the main slide valve F is a piston working in a subsidiary cylinder controlled
by the slide valve R. Both valve rods are connected to the vibrating lever, the
connection of the main rod being by a pin K and slot H. When the piston G
strikes the end of the tappet A it moves the end of the lever until the end of the
slot at H strikes the pin K and pushes the valve F backwards so as to close the
two ports P, P. At the same time the valve R opens the port J, and the steam
acting on the piston E. carries the valve F. to the end of its travel. The object of

page_text: this arrangement is to prevent the engine stopping at the end of its stoke when
working slowly.
In our Provisional Specification we proposed that apparatus according to our
Invention should be so arranged that the same apparatus could be used either as a
hydraulic, a compressed air, or a vacuum brake.
We also proposed in another arrangement of our apparatus to provide a cylinder
containing a piston fitted with two cup leathers back to back, and with two cup
leathers similarly arranged on the piston rod. Round the centre of the piston's
periphery we proposed to construct a groove, in connection with which on one side
of the piston was a small valve, so that when vacuum was employed, it was formed
round the groove, preventing any strain being put on the leather which was
designed to serve when compressed air or hydraulic power was employed.. We also
proposed as the leathers in pneumatic cylinders become hard and dry to provide
them with a hole right through the piston rod and piston, so that lubricant might
be forced through the piston rod and into the top part of the cylinder between the
two cup leathers, so as to fall away on each side of the cylinder and lubricate the
leathers, a small hole with screwed plug being provided between the two leathers
on the piston rod for the same purpose, and also a small valve in connection with
the centres of the two leathers, so as to act when the brake was worked by vacuum
only. Or in lieu of the above we proposed to provide a twisted bar fixed in the
end of the cylinder and extending into the piston rod; or to fix a pawl either to
the cylinder cover or piston, so as to work round a ratchet path, which in the one
case was on the piston, and in the other case was on the cylinder cover, for the
purpose of causing the piston to make a partial revolution each time the brake was
applied, and at the same time to carry lubricant from the bottom of the cylinder
round with it.
We also proposed to construct brakes capable of reversible motion with three
way cocks, with separate valves and chambers in connection with the receiver, and
the cylinder or its equivalent. Also to construct brake levers worked by the use,
in lieu of a cylinder and piston or pistons, of a collapsible vessel with a piston
placed in its centre, allowing the compressed air to act on one side when the brake
was in use by compressed air, and forming a vacuum in the opposite side when
worked by same.
We also proposed to use instead of the small collapsible vessel, a balance weight
or spring.
We also proposed to construct four small side rods sliding on the piston pins
with long slots, two connected to each of two cross-heads, these cross-heads being
such as are now fastened one on one end of each of the small auxiliary cylinders or
collapsible vessels, to allow the brake to operate by pressure or by vacuum.
We also proposed to effect the automatic taking up of the brake blocks as they
wore, by the use of compound rods jointed to a cross bar which carried a brake
block at each of its ends. Each of the longitudinal compound rods was formed in
two lengths with a left hand and a right hand screw thread, connected by a long
nut with right and left handed threads: This nut we proposed to make at both
ends to form a ratchet pinion, so that when the levers were forced back and the
brake blocks opened from the wheels, pawls on the levers should cause the nuts to
turn, thus shortening the compound rods, and other pawls should keep the nuts
from turning back again.
As now we no longer attach importance to the various arrangements we have
just referred to, we do not lay claim to them, but what we consider to be novel and
original, and therefore claim as new and secured to us under the Letters Patent
hereinbefore in part recited is,―
1. The combination with a brake cylinder and a receiver or accumulator, of an
automatic reversible check valve between the train pipe and receiver or accumulator,
and controlling valves that automatically regulate the communications between the
receiver or accumulator and the cylinder, and between the cylinder and the
external atmosphere; the whole so arranged as to form a compound brake capable

page_text: of adapting itself automatically to work by either compressed air or vacuum,
substantially as described.
"
2. The use in a compound railway brake of automatic valves, such as herein-
before described with reference to Fig. 1, Sheet 1 of the Drawings, for automatically
regulating or controlling the communications between the receiver or accumulator
and the cylinder, and between the cylinder and the external atmosphere.
3. In an automatic railway brake, the combination with the receiver or
accumulator and the train pipe of a check valve that will automatically close on
the pressure in the train pipe, falling below that in the receiver or accumulator
when compressed air is being used, also on the pressure in the train pipe exceeding
that in the receiver or accumulator when a vacuum is being used, substantially as
described..
4. The automatic reversible chock valve comprising a chamber with two seats
facing each other, between which works a hollow valve formed with air passages,
and controlled by pressure of air acting against a flexible diaphragm (or equivalent
means), such valve containing other valves arranged and operated, substantially
as herein before described.
.
5. The improved brake operating mechanism constructed, arranged and operating
as shewn in and described with reference respectively to Fig. 1, to Fig. 2, to
Fig. 3, and to Fig. 4, all on Sheet 3 of the accompanying Drawings.
6. The use for retaining vacuum or compressed air in a train pipe, of a valve
having two faces in combination with a chamber having two seats, and means for
operating the said valve automatically, substantially as hereinbefore described with
reference to Fig. 1, 2, 3, 2ª, and 2b, on Sheet 8 of the Drawings.
7. The combination of parts constituting the improved hose or pipe coupling,
constructed, arranged, and operating, substantially as described with reference to
Figs. 1 and 2, on Sheet 9 of the Drawings.
8. The combination of parts constituting the improved hose or pipe coupling,
constructed, arranged, and operating, substantially as described with reference to
Figs. 1, 2, 3, and 4, on Sheet 9 of the Drawings.
9. Arranging the valves in a steam engine, substantially as hereinbefore
described with reference to Figs. 1, 3, and 4, on Sheet 10 of the Drawings.
10. Arranging the valves in a steam engine, substantially as hereinbefore
described with reference to Figs. 5 and 6 on Sheet 10 of the accompanying
Drawings.
In witness whereof, I, the said William Timbrill Clark, for myself and on
behalf of the said William Henry Ashwell, have hereunto set my hand and
seal, this Twenty third day of December, in the year of our Lord One
thousand eight hundred and eighty.
W. T. CLARK. (L.S.)