Improvements in Drivers' Valves for Pneumatic Railway Brakes.
Year: 1892

page_text: Date of Application, 5th Jan., 1892-Accepted, 6th Feb., 1892
COMPLETE SPECIFICATION.
[Communicated from abroad by CHARLES GOODWIN EMERY, of New York City,
New York, United States of America, Manufacturer.]
Improvements in Drivers' Valves for Pneumatic Railway Brakes.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, 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:-
This invention relates to the valve worked by the driver of a locomotive for the
purpose of determining the pressure in the train pipe of pneumatic brake mechanism,
particularly of that kind wherein a piston has equal pressure on both sides while
the brakes are off, and the brakes are put on and taken off by relieving and
restoring the pressure on the one side of the piston.
The object of my invention is to provide a driver's valve such that the brakes
can be put on gently or gradually, or suddenly in case of emergency, and can be
taken off without requiring any skill or experience on the part of the operator.
Fig. 1 of the accompanying drawings is a vertical section of a valve according
my invention.
to
Fig. 2 is a sectional plan on the line - Fig. 1, with the valve in position to
charge the train pipe.
Fig. 3 is a similar view shewing the valve in position to maintain the pressure in
the train pipe and brake cylinders.
Fig. 4 is a similar view shewing the valve in position for slow release of the
pressure and consequent gradual application of the brakes.
Fig. 5 is a similar view shewing the valve in position for rapid release of the
pressure and consequent sudden application of the brakes.
Fig. 6, is a plan of the valve and handle.
Fig. 7, is a vertical section on the line y-y of Fig. 6.
Fig. 8, is a plan of the valve plugs.
Fig. 9, is a perspective view of the device by which the two plugs are turned.
Fig. 10, is a perspective view of the exterior valve plug, and
Fig. 11 is a perspective view of the interior valve plug.
1. is the valve casing having a central conical valve plug chamber, a pair of
opposite passages 2 and 3, for connecting respectively with the main compressed
air reservoir on the locomotive and with the train pipe, a port 4, and outlet 5, to the
open air and an outlet port 6. of less area. The ports.4 and 6 are for escape of
air to relieve the pressure.the one for the sudden the other for the gradual applica-
tion of the brakes, as the port 4 permits the more rapid reduction of the pressure
than the smaller port 6. The passages 2 and 3 communicate with the valve
chamber by transverse channels 7 and 8 governed by the duplex valve plug.
The conical valve chamber is fitted to receive an exterior conical valve plug 9,
within which is fitted to turn a smaller conical valve plug 10. The two valve plugs
have transverse channels 12 and 13, which can be put in coincidence with each
ther and with the channels 7 and 8, in which position the compressed air can pass
rom the main air reservoir by the passages 2 and 3 to the train pipe.
The exterior plug 9, is cut away at one side to form a cavity 14, and opposite
his cavity the plug has a port 15, equal to the port 6, in the casing. The interior
lug 10, has a small port 16 which communicates with the channel 15, and can be
ut in coincidence with the ports 15 and 6 to permit slow release of the fluid
ressure in the train pipe. In the side of the channel 13, is cut a notch 17,
Fig. 11,) which comes in line with the channel 8, when the ports 15 and 6 are in
oincidence as shewn in Fig. 4.

page_text: The upper end of the plug 9 is formed with a pair of segmental recesses 18, in which
can play a rib 19, formed on the underside of a disc 20, which is journalled in the
cap 21, of the valve casing and has attached to it the handle 22. The upper end
of the interior plug 10 has a transverse groove 23, with which engages the rib 19,
so that when the disc 20 is turned by the handle 22, the interior plug 10 is corre-
spondingly turned but, owing to the width of the recesses 18, the interior plug 10
can be turned to a certain extent without turning the exterior plug 9.
In Fig. 2 the parts are shewn in position for the free passage of compressed air
from the main reservoir into the train pipe, and in Fig. 3 they are in position to
maintain the pressure in the train pipe, a small quantity of air flowing into the
train pipe to compensate for leakage by a passage 24" formed by slightly beveling
the edge of the port 12. A plate 24 is bolted to the underside of the valve
casing and between this plate and the lower end of the exterior plug 9 is placed
a helical spring 25, a helical spring 26, of less strength being similarly placed
under the interior plug 10. These springs press the plugs upwards and since the
one spring is of greater strength than the other it requires greater force to turn
the exterior plug 9 than to turn the interior plug 10.
The plate 24, has a hole 27, for escape of air that might accumulate beneath
the plugs. When it is desired to apply the brakes gradually, as when stopping at
a station, the driver moves the handle 22 to turn the interior plug 10 from the
position shewn in Fig. 3, until the rib 19 of the disc 20 bears against the sides of
the recesses 18 of the plug 9 at which instant the port 16 is in line with 15, which
is in line with the small port 6, as in Fig. 4, allowing gradual release of the pressure
for the gradual application of the brakes. The driver is made aware of the ports
coming to the position Fig. 4 by feeling that the rib 19 is brought against the sides
of the recesses 18, and since greater power is required to turn the exterior plug 9,
than to turn the interior plug 10, the driver can thus accurately determine, by his
feeling the increased resistance, that the ports are in position for the gradual
release of pressure, and can thus determine that by further turning of the handle 22,
he can place the ports in the position shewn in Fig. 5, for the rapid release of the
pressure, in order to apply the brakes suddenly. Thus there is no liability of his
inadvertently turning the plugs to such extent as to effect the sudden application
of the brakes.
In the case of an emergency, the handle 22 is moved turning both plugs until a
stop-lug 28, on the handle, strikes the stop 29 the cavity 14 of the exterior plug 9
being thus brought to make communication between the enlarged channels 8 and 4,
as shewn in Fig. 5, so that the fluid can rapidly escape through the outlet 5. When
the handle is turned back until the stop lug 28, bears against the stop 30, the plugs
are brought to the position shewn in Fig. 3, to maintain the reservoir pressure in
the train pipe.
Obviously the speed of release of the fluid pressure through the port 6, can be
varied by putting a greater or less portion of the port 16 in communication with
the ports 15 and 6. As the normal position of the plugs maintaining pressure in
the train pipe, is as indicated in Fig. 3, the port 15 then connecting with 6, it
is only necessary to turn the interior plug alone, to effect gradual application of
the brakes.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a driver's valve for pneumatic brake apparatus, in combination with a valve
casing, having passages connecting with the main reservoir, the train pipe and the
open air, a pair of rotating valve-plugs with suitable ports, the one plug turning
within the other, means for partly turning the interior plug independently of the
exterior plug and for then turning both together, and springs of different strength
acting respectively upon the interior and exterior plugs substantially as described.
2. In combination with the two outlets of different areas, the exterior plug 9,

page_text: having opposite ports 12, quick release cavity 14, and slow release port 15, the
interior plug 10 having transverse channel 13, slow release port 16, and notch 17,
and the handle having an attached disc with rib engaging a groove in the end of
the inner plug and segmental recesses, in the end of the outer plug arranged and
operating, substantially as described.
Dated this 5th day of Janua 1000
ABEL & IMRAY,
Agents for the Applicant.