mprovements in Train Pipe Valves for Pneumatic Brake Systems.
Year: 1893

page_text: COMPLETE SPECIFICATION.
mprovements in Train Pipe Valves for Pneumatic Brake Systems.
I WILLIAM CURTIS WHITACRE of No. 304 North Eighth Street in the City
of St. Louis, State of Missouri United States of America Gentleman, do hereby
leclare 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
tatement:—
My invention relates to improvements in and to devices, to be used by drivers on
ocomotives, for controlling the air to the train-pipe from the main reservoir in
pneumatic air-brake systems. It has for its object to simplify and, consequently
cheapen its construction, and in the valve, as a whole, to make provision, in
combination with means for regularly admitting air to the train pipe under a given
pressure, for readily turning into the train-pipe the full pressure from the main
reservoir. The invention consists in the details of improvement in construction and
consequent operation, in such a device, hereinafter described.
In the accompanying drawings, in which like numbers of reference denote like
parts in the several figures,
Fig. 1, is a side elevation of the handle side of my new valve;
Fig. 2 is a diametrical section, partly in elevation, taken on a line corresponding
to the axis of the valve operating cam-shaft ;
Fig. 3, is cross section taken as on the line 3-3 Fig. 1,
Figs. 4 and 5 are similar sectional views taken as on the line 4-5 in Fig. 2 at
right angles to the valve operating cam-shaft; and
Fig. 6 is a detail sectional view, taken similar to Figs. 4 and 5, showing the
method of operation of the auxiliary full pressure valves, hereinafter described.
1, is the cylindrically formed casing of the main part of the valve which is open
at both ends and has formed near its upper end, in the side walls thereof, the outlet
openings 2. The casing is also formed with a laterally projecting nozzle 4 to
which the end of the train-pipe may be secured. This nozzle 4, is also formed
hollow, thereby affording a communication opening or port 5, from the interior of
the valve to the train-pipe and parts connected therewith. The interior of the
valve casing 1, is bored out, or otherwise formed, concentrically to two different
diameters, forming the main valve chamber relatively reduced diametrically, in the
middle portion of its length, as at 6, and relatively enlarged at either end, as at 7
and 8. The shoulders formed at either end by the relatively enlarged portions 7
and form a seat for the two winged puppet valves 9 and 10, respectively, which
are rigidly connected to a common valve-stem 11.
The upper surface of the upper valve 9 is formed with a projection 38 the upper
surface of which is formed curved, substantially concentric with the axis of the cam
shaft 27, hereinafter described, whereby the longitudinal movement of the valves 9
and 10 is not due to any eccentricity in the contact face of the projection 38.
The upper end of the valve casing is closed by the screw cap 12, and into the
lower end is screwed the closing piece 13, which practically forms an extension of
the casing 1, and which is formed hollow to a convenient distance from its lower
end to form a convenient valve chamber 17 for the spring winged valve 14. The
valve 14 is vertically placed and operates, by the spring 15, to close the opening 16
(see Fig. 5), formed through the upper end of the closing piece 13, communicating
directly between the valve chamber therein and the main valve chamber 8-6. It
is in the lower circumferential edge of this perforation 16 that the seat for the
valve 14 is formed. The valve 14 is formed with a longitudinal upwardly
extending stem 32, which projects up through a central longitudinal perforation
formed therefor in the valve stem 11, and a downwardly extending stem portion 18,

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around which the valve spring 15 is placed, and which has a guide bearing in a central
perforation formed therefor in the upper perforate end of the closing block 19.
The block 19, forms the lower extremity of the valve as a whole, to which the pipe
connecting it to the main reservoir is connected and through which the com-
municating port 20, therebetween, is formed.
In the side wall of the piece 13, is formed a laterally extending perforation 24
into which is fitted the spring seated cup-valve 21. The outer end of the per-
"foration is closed by the screw cap 22, between, which and the valve 21, is placed
the spiral spring 23. The extreme inner end of the perforation is diametrically
reduced to form a convenient seat 26 for the valve 21.
In the side wall of the piece 13, is also formed the longitudinally extending
communication port 25 which forms a passage-way from a point in the per-
foration 24, back of the valve seat 23, to the main valve chamber, 8-6.
Across the upper end of the valve casing 1, is diametrically placed and revolubly
secured, by the retaining screw 28, the valve operating cam-shaft 27. One end of
this shaft projects from the casing and has rigidly secured thereto the valve
handle 29. To approximately the middle of the length of the shaft 27 is rigidly
secured, by the set-screw 30, the duplex or double eccentric cam 31. One of the
two eccentric surfaces of the double cam 31, as 40 (see Fig. 6) is adapted to engage
with the central auxiliary valve-operating rod 32, and the other, as 37, with the
curved surface of the projection 38 of the main valve 9-10.
The handle 29 is provided with a spring governed retaining-pawl 33 (see Fig. 2)
which engages, in the movement of the handle 29 about its axis, with notches 39,
35 and 36 (see Fig. 1) formed therefor in the circumferential edge of the pawl
segment 34 rigidly secured to the side of the valve casing 1.
The principles of operation are as follows:-
The normal position of the valve is, as shown in Figs. 2 and 4, with the valve 9
forced home to its seat by the relatively diametrically enlarged portion 37, of the
main valve cam engaging with the concentrically curved surface of the projection 38,
thereby forcing the connected valves 9 and 10 downward against the accumulated
pressure of air in the valve and connected parts. In this position of the handle it
is retained, against shaking, etc., by the pawl 33 engaging in the pawl notch 35.
In this position of the main valves 9 and 10, communication is established, through
the ports 20 and 5 and the communicating duct 25 and controlling valve 21, from
the main reservoir to the train-pipe.
When it is desired to apply the brakes, which in this instance, is effected by
reducing the air-pressure in the train pipe, and thus, at the driver's valve, the
co-acting parts of the valve must be so placed that communication between the
main reservoir, connected to the valve through the lower port 20, and the train-
pipe, connected to the valve through the port 5, is prevented, and the air in the
train-pipe allowed to escape. This position of the different parts of the valve is
shown in Figs. 1 and 5. The handle is thrown to one side-the left in Fig. 1, the
right in Fig. 5-from its normally vertical position as shown in Fig. 4.
In this
manner, the radially reduced portion of the cam 37 is brought into engagement
with the upper extension 38 of the valves 9 and 10, allowing the valves to rise as
impelled by the accumulated pressure in the main reservoir, as well as in the train
pipe, behind and below the same. The valve 10 will be seated, closing com-
munication from the main reservoir to the train-pipe. At the same time, the
valve 9 is unseated, and the air in the train-pipe is offered an exit through the
same, and the openings 2, to the exterior atmosphere, as indicated by the arrows
in Fig. 5. When it is again desired to admit the normal pressure of the main
reservoir to the train pipe, to release the brakes, the handle is brought to the
vertical position, when the conditions indicated n Fig. 4 are again established.
It is evident that the flow of air through the duct 25 is under the control of the
reducing valve 21 and that this control is operative to hold back an excess of
pressure, in the main reservoir, over what is flowing through the valve 21, (i.e., the
normal pressure to the train pipe), the amount depending on the pre-determined

page_text: strength of the spring 23; that is, if the strength of the spring is equal to twenty-
five pounds, the flow of the compressed air from the main reservoir to the train pipe,
through the valve 21 and duct 25, will only begin when the pressure in the main
reservoir has reached twenty-five pounds, the valve operating to hold back, at all
times, this excess.
When, for any reason, it is desirable to make use of this excess of pressure in
the train pipe and parts connected therewith, a direct passage for the flow of the
air from the main reservoir thereto, around the valve 21, is effected through the
valve 14 by throwing the handle 29 in the opposite direction, so shown in dotted
lines in Fig. 4, from that by which the application of the brakes is effected-to
the left in Figs. 4, 5, and 3, to the right in Fig. 1-until the pawl 35 rests in the
notch 39-by which means the operative offset 40 in the second part of the duplex-
cam comes into engagement with the upwardly extending stem portion 32 of the
valve 14 depressing the same and opening the valve.
The operative feature of improvement of the above described arrangement, to
store up an excess of pressure in the main reservoir over the pressure normally
admitted to the train pipe, and in providing means by which the excess of pressure
is readily admitted to the train-pipe is, that this excess can be used to positively
and quickly operate the triple valves when from sticking, &c., they refuse to
operate with the normal train pipe pressure. It is also effective as an emergency
release.
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 :-
I. The combination with the valve casing and ports leading therefrom to the
main reservoir and train pipe, a valve between said ports for automatically
establishing communication between the main reservoir and the train-pipe at a
given pressure in the former, valves for controlling direct communication between
the several ports, and a handle for operating said valves, substantially as
described.
11. The combination with the valve casing provided with ports leading there-
from to the main reservoir and to the train pipe and outlet openings to the external
atmosphere, of a valve for controlling communication between the said ports, a
valve controlling communication between the port to the train pipe and the outlet
openings, the said valves being connected together and being provided with an
extension adapted to be engaged with a cam, of an eccentric cam, adapted to move
the valves longitudinally, a shaft for the cam, and a handle to operate the shaft ;
substantially as and for the purposes described.
III. The combination with the valve-casing, provided with ports leading there-
from to the main reservoir and to the train pipe and outlet openings to the exterior
atmosphere, valves for controlling communication between the said ports, and
between the train-pipe port and the outlet openings secured to a common valve-
stem, a cam-shaft, and handle for operating said valves, and an automatic
reduction valve between said ports, of a short port between the aforementioned
ports, and a valve for controlling said port; substantially as and for the purposes
described.
IV. The combination with the valve-casing provided with ports leading there-
from to the main reservoir and to the train-pipe and outlet openings to the exterior
atmosphere, valves for controlling communication between the said ports and
between the train pipe port and the outlet openings, said valves being centered to a
common valve-stem, an automatic reducing valve between the said ports, of a short
port between the aforementioned ports, a valve for closing the short port, a double
eccentric cam for operating the said controlling valves and the short port valve,
and a cam-shaft and handle for operating the cam, substantially as and for the
purposes described.
V. The combination with the valve casing internally formed to two different

page_text: diameters, with a relatively enlarged portion at each end, the train-pipe port
leading from the relatively reduced middle portion and the main reservoir port and
outlet openings from either of the relatively enlarged end portions, respectively, of
valves for controlling communication between the said ports and between the train
pipe port and the outlet openings, said valves being secured to a common valve-
stem and being seated, respectively, in the shoulders formed by the relatively
enlarged portions, substantially as and for the purposes described.
VI. The combination with the controlling valves 9 and 10 secured to a common
hollow valve-stem 11, formed with extensions 38, the short-port valve 14, the valve
stem 32 of which projects up through the hollow valve-stem 11, double eccentric
cam 31, cam-rod 27, and handle 29, substantially as and for the purposes
described.
Dated the 28th day of March 1893.
PHILIP M. JUSTICE,
Chartered Patent Agent for the Applicant.