Improvements in Pneumatic Brakes for Railway Vehicles...
Year: 1895

page_text: Date of Application, 23rd July, 1895-Accepted, 16th Nov.; 1895
COMPLETE SPECIFICATION.
Improvements in Pneumatic Brakes for Railway Vehicles...
I, HARVEY SLAUGHTER PARK, Mechanical Engineer, of 3733 Langley
Avenue, Chicago, Cook County, Illinois, United States of America, 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:-
The object of my invention is to provide a quick acting brake, which shall be
simple in construction and positive and reliable in operation.
In the drawings,.
Fig. 1 is a cross section of the valve apparatus on line 1 of Fig. 8:
Fig. 2 is an elevation (parts being broken away) of the head of the brake
cylinder showing the passage from the valve apparatus to the car reservoir and
brake cylinder;
Fig. 3 is a face view of the slide-valve:
Fig. 4 is a cross section on line 4 of Fig. 1:
Fig. 5 is a sectional view on line 5 of Fig. 8 showing the position of valve
apparatus when making service stops.
Fig. 6 is a sectional view on line 6 of Fig. 8, showing position of valve apparatus
when making emergency stops:
Fig. 7. a cross section on line 7 of Fig. 1:
Figs. 8 and 9 cross sections taken on lines 8 and 9 respectively of Fig. 6
Fig. 10 a view in elevation of a part of the valve chamber:
10
Fig. 11 a view of the casing in elevation and partly broken away showing
route for venting air from the train pipe to the brake cylinder and
Fig. 12 a view in elevation showing the apparatus fixed to a brake cylinder.
The operation of a valve apparatus for venting from a car reservoir to a brake
cylinder by means of a slide-valve located in a chamber and operated by a piston
is well known and need not be dwelt upon further than to describe the working of
the same.
4.)
In the drawings A is a casing forming the chamber in which the. apparatus
actuates and A' is a bushing firmly fixed therein so as to be air tight.
"
The chamber C is made in the form of a cylinder, having its upper part smaller
in diameter than its lower part. In the upper part of the chamber is located and
operated the slide-valve D, actuated by the piston B which operates in the lower
part of the chamber. This valve is actuated by the stem. B₁ extending into the
5 upper part of the chamber and provided with a shoulder on its lower end and a
head on its upper end. This stem actuates the slide-valve in its upper movement
by its shoulder abutting against the arms that extend from the back of the slide-
valve and across the chamber, forming a guide for the valve. This stem actuates
the valve on its downward travel by its head abutting the arms extending from the
0 upper part of the valve. These arms cross the chamber and form a guide for
the valve whereby the latter may travel up and down in a channel or guide way
cut in the bushing A¹.
In the casing is the passage E leading to the brake cylinder K, downward and
into the chamber C. From this chamber is a passage E' leading to the
15 passage E and also a passage E2 through the casing to the atmosphere
A passage E³ in the casing A connects, with passage. E' and through..i
.communicates with the atmosphere.

page_text: .
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'
The slide-valve is provided with a large recess d to connect the ports for
venting the train pipe air to the brake cylinder and also with a small recess d¹ to
connect the lower end of passage E and passage E2 to form an open way to the
atmosphere from the brake cylinder. A recess d is also made in the slide-valve
and is adapted to form a passage from the chamber F with the passage E³ making
an open way to the atmosphere.
A casing L is fixed to the lower end of casing A closing its lower end and
forming chamber L' provided with a communicating side chamber l, into which is
fixed the train pipe N. Chamber-L-has a passage or passages communicating
with the chamber C while chamber has a passage communicating with the
passage G in the wall or casing. This passage G extends upward and inward
and its upper and inner end connects with the chamber C but is covered by the
slide-valve.
.
A chamber F is formed in the casing A and has a connection with chamber C
through a passage G but is covered by the slide-valve; the upper end of
chamber is connected with the brake cylinder by the passage H formed in
the head I of the brake cylinder. The recess d in the slide-valve is so formed
that when the valve has made its full travel downward the recess connects
passages G and G', in such manner that by means of chamber
passage G
passage G chamber F and passage H, a direct communication is formed from
the train pipe to the brake cylinder. In chamber F is located valve Fi connected
to piston F, and held to its seat by air pressure from the train pipe, entering from
the train pipe through passages G and g and recess d and passage g', to the under
side of the piston F. The valve F¹ is seated on a valve seat formed on the lower
end of tubular flange flocated in the chamber F, through which flange a passage
is formed connecting chamber F with passage H. in the head of the brake
cylinder. In the passage H is located the valve F³, seated on a gasket pressing
against flange and having its upper stem working in a guide formed in the head
of the brake cylinder. This stem is surrounded by a spiral spring pressing
against the valve and guide. The lower stem of the valve passes downward into
chamber F and is of a tubular form, the tube forming a guide for the stem of
valve F. The valve Fs lifts when the air flows from the train pipe to the brake
cylinder, but is beld to its seat when the brake is set for service stops by air from
the car reservoir. In chamber L is located a stem M, whose upper end passes
through the wall L and terminates in the chamber C. This stem has a shoulder
that abuts against the wall L to prevent its further upward travel, and is
surrounded by a spring abutting against the under side of the shoulder, the lower
end of the spring pressing against a nut L2 screwed into the casing L. A
passage His formed in the head of the brake cylinder, one end of this passage
connecting with the upper end of the chamber Ċ and communicating at its other
eud. with the pipe H2 which connects with the car reservoir.
The operation is as follows: All of the parts of the device being in their normal
position as shown in Fig. 1, air being pumped into the train pipe N, enters the
chamber 1, passes into the chamber L and into chamber C below the piston, and
passes by means of a by-port a, in the wall A around the piston B, and into the
upper part of the chamber C, and through the passage H¹ in the brake cylinder
- head to the pipe H2 and to the car reservoir.
The air from the train pipe will pass from chamber to passage G, and to the
under side of the slide-valve, also from passage G into passage g and to recess d and
from recess d into the passage g¹ and into chamber F, under the piston F2 and hold
the valve F1 seated. The piston F2 is not fitted to the chamber F to be perfectly
air tight and the air will slowly pass the piston into the chamber Fabove the
piston and hold the valve F firmly seated, and the air will also pass into
the passage G and to the under side of the slide-valve at the lower end of the
passage G¹. The air from the train pipe being in the passage G pressing against
the slide-valve and also in passage G pressing against the slide-valve, and in the
recess d, the same pressure per square inch being on the opposite side of the valve

page_text: chamber C will perfectly balance the valve.
This balanced
nsequently be easily moved by a small reduction of pressure in the train pipe,
d to hold it perfectly to its seat, the curved spring O is fixed in chamber C
ressing against the bushing A' and also against the arms or guides for the slide-
alve, thus giving the valve a perfect seating.
In operation the pressure being slightly reduced in the train pipe, the piston will
ravel downwards by reason of the excess of pressure on its upper side, and carry
he slide-valve with it. The piston will continue to move downwards until the
ower end of its stem abuts the stem M, when its travel will be arrested by the
The downward movement of
esistance of the spiral spring around the stem.
he slide-valve will close the port E2 to the atmosphere, and when the piston abuts
tem M, the slide-valve will uncover passage E', when the air from the car
reservoir will pass through passage E¹ and E to the brake cylinder and set the
brakes. When the pressure in the car reservoir has been reduced to a pressure
slightly lower than that in the train pipe, by reason of air flowing into the brake
cylinder, the piston will move the valve upward and close the passage El, but
not sufficient to open the port E2 and the brakes will remain set. During this
passage H will prevent the air from entering
operation the valve F³ in
chamber F. When the pressure is restored in the train pipe the piston B will
return the slide-valve to its normal position as shown in Fig. 1 connecting the
In the foregoing operation the slide-valve
ports E and E2 and release the brakes.
did not travel sufficiently far to have recess d connect passages G and G', nor to
close the passages g and y' from recess d.
The position of the slide-valve as described in the foregoing is shown in
Fig. 5.
When it is necessary to set the brakes quickly for an emergency a reduction in
the train pipe pressure is made sufficient to have the pressure above the piston B
overcome the resistance of the spring around the stem M, and the piston will travel
to its fullest extent, to the position shown in Fig. 6, and carry with it the slidė-
valve. The recess d will connect passages G and G' as the slide-valve travels
downward but before connecting thein it will close passages g and g' from recess d,
and as the connection from passage G to passage G₁ is made, the recess will
connect passages 91 and E³ forming an open way from chamber F below the
piston F to the atmosphere, when the air pressure above the piston in chamber F
will move it 'downward and seat it on a gasket located in the bottom part of the
chamber F and make an air tight seating. This will form a large direct passage
from the train pipe to the brake cylinder, that will quickly admit the train pipe
air to the brake cylinder. In this position the slide-valve will uncover ports or
passages E and E' and the car reservoir air will flow to the brake cylinder, and all
O the brakes will set quickly, when the car reservoir air is added to the train pipe
air in the brake cylinder, the pressure in the brake cylinder will be greater than
The position of the piston B,
that in the train pipe, and valve F3 will close.
piston F2 stem M, slide-valve D, valve F', valve F³, and the connection between
the ports and passages in this operation is shown in Fig. 6.
43
To release the brakes, the pressure in the train pipe is restored, whereby the
piston will travel upward, moving the slide-valve closing the connection between
the passages G and G', and closing the passage from chamber F to the atmosphere.
Passages g and g¹ will then be connected by recess d, when the air from the train
pipe will flow to the lower part of chamber F under the piston F2 and the piston
Further travel of the piston and slide-valve will connect
50 will seat valve F.
recess d' with the ports E and E and release the brakes at which time all the parts
will be in their normal position as shown in Fig. 1.
In actuating brukes for an emergency seconds of time are extremely valuable and
as it is essential that a simultaneous action of the brakes be had throughout th
55 entire train, so that the brakes can be set to their best retarding force withou
detriment to the train or load, at any speed. Heretofore a nearly simultaneou
action has been attempted by venting car reservoir and train pipe into the brak

page_text: cylinder by electrically actuated valves, and by what is known as a triple valve in
combination with an auxiliary valve device.
I have in this invention constructed a slide-valve that is balanced as to the ports
passages and recess between the train pipe and brake cylinder, that will move
quickly with a slight reduction of train pipe pressure and open a large and direct
passage from the train pipe to the brake cylinder, whereby the train pipe can be
emptied into the brake cylinder throughout the entire length of the longest train
in a very short period of time, producing a practically simultaneous setting of the
brakes on the entire train.
Furthermore the slide-valve is moved in every application of the brakes,
actuates the brake mechanism at service stops, and also forms the operating
device of the emergency part of the construction, so that it is always in working
condition for emergency purpose.
In those constructions where the emergency
device is called into action only when required, which is rare, the valve mechanism
is liable to stick and fail to respond on account of rust or accumulated dust and
dirt. My slide-valve is for both service and emergency stops, so that its free
quick and positive operation for the latter purpose is always assured.
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. The combination of a train pipe, a car reservoir, a brake cylinder, and a
single balanced slide-valve arranged to set the brakes by air pressure from the train
pipe and car reservoir.
2. The combination of a train pipe, a car reservoir, a brake cylinder and a
balanced slide-valve to admit air from the car reservoir and train pipe, to the brake
cylinder.
3. In a valve mechanism for actuating railway brakes, a balanced slide-valve
controlling direct. ports and passages between a train pipe and
cylinder.
a brake
4. The combination of a train pipe, a car reservoir, a brake cylinder and a
balanced slide-valve actuated by a piston, the preliminary travel of the valve
admitting air from the car reservoir to the brake cylinder, and the further travel
admitting air from the train pipe direct to the brake cylinder.
5. In a brake mechanism, the combination of a chamber or casing communicating
respectively with the car reservoir, brake cylinder and train pipe, a piston adapted
to travel within the chamber, a passage leading from the train pipe directly to the
brake cylinder, and a balanced slide-valve, actuated by the piston and adapted to
govern the ports or passages leading to the brake cylinder, from the chamber and
train pipe respectively.
6. In a brake mechanism, the combination of a chamber or casing communicating
with the auxiliary reservoir and brake cylinder, a passage leading from the train
pipe and communicating with the brake cylinder, a piston adapted to travel in the
chamber, and a slide-valve actuated by the piston and balanced by the train pipe
pressure and reservoir pressure respectively, the valve being adapted to govern
the ports and passages to the brake cylinder respectively from the chamber and
train pipe.
7. In a brake mechanism, the combination of a chamber or casing communicating
with the auxiliary reservoir and brake cylinder, a passage from the train pipe
communicating directly with the brake cylinder, a piston adapted to travel within
the chamber and provided with a stem, and a slide-valve arranged within the piston
chamber, and connection to the piston stem, such valve being balanced by reservoir
and train pipe pressure respectively upon its opposing faces and adapted to govern
ports and passages to the brake cylinder respectively from the chamber and
train pipe.
8. In a
railway brake mechanism, a balanced slide-valve in combination with a
train pipe and a brake cylinder, arranged to have air pressure in the port from the

page_text: train pipe to the slide-valve, and in the port from the slide-valve to the brake
cylinder to be always of such pressure that the valve will at all times be in a
balanced condition, with means for actuating the valve for veuting the air direct
from the train pipe to the brake cylinder.
9. In a fluid brake mechanism, a slide-valve arranged to vent fluid under
pressure from a train pipe to a brake cylinder, through a direct passage from
the train pipe, and a valve located in the passage and adapted to maintain an
equal pressure in the ports governed by the slide-valve, in such direct passage, with
means for actuating the valve.
10. In a railway brake mechanism, a slide-valve arranged to vent air from a
train pipe to a brake cylinder, through a passage from the train pipe to the brake
cylinder, a valve located in the passage and adapted to maintain a balanced pressure
on the slide-valve, a passage to the atmosphere governed by the slide-valve and
suitably fixed to move the valve in the passage from the train pipe to the brake
cylinder, with means for actuating the slide-valve.
11. In a railway brake mechanism, for actuating railway brakes, a slide-valve
arranged for venting train pipe air into the brake cylinder, in combination with a
balancing valve.
12. In a brake mechanism, the combination of a chamber communicating with
the auxiliary reservoir and brake cylinder, a passage leading from the train pipe
and communicating with the brake cylinder, a slide-valve adapted to travel within
the chamber and govern the ports to the brake cylinder from the auxiliary reservoir,
and train pipe respectively, and means for balancing the slide-valve against the
pressure in the chamber.
13. In a brake mechanism, the combination of a chamber communicating with
the auxiliary reservoir and brake cylinder, a passage leading from the train pipe
and communicating with the brake cylinder, a slide-valve adapted to travel
within the chamber, and to govern the ports to the brake cylinder, from the
auxiliary reservoir and from the train pipe respectively, and ports opening
against the slide-valve and communicating with the train pipe whereby the
pressure on both sides of the valve will be same pressure per square inch area.
14. In a brake mechanism, the combination of a chamber communicating with
the auxiliary reservoir and brake cylinder, a passage leading from the train pipe
and communicating with the brake cylinder, a slide-valve adapted to travel
within the chamber and govern the ports to the brake cylinder from the
auxiliary reservoir and from the train pipe respectively, passages opening
against the valve and communicating with the train pipe, such passage forming
a local circuit fed with train pipe air, and a balancing valve located in such
circuit.
Tlated this 23rd day of July 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.