Self-acting Anti-vacuum Valves for Locomotive Cylinders.
Year: 1893

page_text: Date of Application, 25th Feb., 1893
Complete Specification Left, 23rd Nov., 1893-Accepted, 23rd Dec., 1893
PROVISIONAL SPECIFICATION.
Self-acting Anti-vacuum Valves for Locomotive Cylinders.
I FRANCIS WILLIAM WEBB of Chester Place, Crewe, in the County of
Chester, Mechanical Engineer, do hereby declare the nature of this invention
to be as follows :-
The object of my invention is to provide a self acting anti-vacuum valve or
valves in connection with the cylinders of a locomotive engine so that air may
be freely drawn into the cylinders preferably through the steam chest or chests,
when the locomotive is running with the steam shut off, and thus free the movement
of the pistons, which is now more or less retarded by their effort to create a
vacuum.
I prefer to place the valve on the front cover of the steam chest or chests
where the air taken in by the valve will be comparatively free from dust, but
any other suitable place will do, and I construct the valve in the form of an
ordinary clack or other suitable form which may either open by gravity or by the
suction action of the moving pistons when steam is shut off, and which may close
either by gravity or by the pressure of steam when steam is turned on.
To prevent particles of dust being drawn into the cylinders and valve chest
a piece of fine wire gauze may be placed over the inlet mouth of the valve should
it be considered necessary.
F. W. WEBB.
COMPLETE SPECIFICATION.
Self-acting Anti-vacuum Valves for Locomotive Oylinders.
I, FRANCIS WILLIAM WEBB of Chester Place, Crewe, in the County of
Chester, Mechanical Engineer, 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 self-acting anti-vacuum valve or
valves in connection with the cylinders of a locomotive engine so that air may be
freely drawn into the cylinders, preferably through the steam chest or chests, when
the locomotive is running with the steam shut off, and thus free the movement
of the pistons, which is now more or less retarded by their effort to create a
vacuum.
I prefer to place the valve on the front cover of the steam chest or chests where
the air taken in by the valve will be comparatively free from dust, but any other
suitable place will do, and I construct the valve in the form of an ordinary clack or
other suitable form which may either open by gravity or by the suction action of
the moving pistons when steam is shut off, and which may close either by gravity
or by the pressure of steam when steam is turned on.
'
To prevent particles of dust being drawn into the cylinders and valve chest a
piece of fine wire gauze may be placed over the inlet mouth of the valve should it
be considered necessary.
Figure 1, Sheet 1, shows a side view of the valve in section. Figure 2, Sheet 1,
a plan of the same in section. Figure 3, Sheet 1, an end view of the same in
section. a Figures 1 and 2 is the steam chest or cylinder cover, 6 Figures 1 and 2
the lagging plate of the same, c Figures 1, 2 and 3 the valve casing, d Figures 1
and 3 a cap piece or stopper secured to the valve casing c by means of a screw
23

page_text: thread, or other suitable connection, and carrying a projecting piece d to limit the
range of lift of the valve, e Figures 1, 2 and 3 is the valve resting on a seating f
formed on the valve casing c, g are wing pieces attached to the valve e to guide its
movement.
Having now particularly described and ascertained the nature of my said 5
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. Supplying air direct to the valve chest and cylinders of a locomotive engine
by a valve or valves opening automatically when the steam is shut off and the
engine moving, and closing automatically when steam is turned on, such valve or
valves to be placed on the valve chest or cylinder ends, substantially as described
and illustrated by the drawing.
Dated this 22nd day of November 1893.