Year: 1899

page_text: I, GEORGE DUNCAN, of 106, Victoria Road, in the City and County of Aberdeen,
Maine Engineer, do hereby declare the nature of my invention to be as follows:-
This invention has reference to an automatic shut off throttle valve, connected
direct to main stop-valve on steam boilers: and whereby in the event of an
explosion, the steam, can be instantly shut off
According to my improvements I use an ordinary valve chest with one end
long enough to allow sufficient space between centie of chest, and centre of
throttle valve to admit steam cylinder to operate valve In the valve chest is
a movable disc which 18 secured to the end of a lever by a cotter, and keyed
on to a shaft in the cover of chest. On one end of this shaft there is a spring
for adjusting the movable disc to suit the working pressure of boilers; and on
the other end of shaft there is a level, with movable catch for keeping disc
from coming back, after an explosion and opening throttle valve, theieby pre-
venting a fresh outlet of steam A lever with sector or toothed lack would oi
may be used for relieving the valve from engine-room, in the case of a sudden
shock with no explosion, as in the instance of water hammering
The end where the throttle valve is placed, is next stop valve on boilers.
By these improvements in the event of a pipe bursting, or a casing dooi in
the high pressure cylinder giving way, the increased velocity or pressure of
steam above that to which the spring has been set operates the disc and the
slide valve of small cylinder that is connected to it, with the result that on
steam being admitted to the cylinder it shuts the throttle valve and prevents a
further inrush of steam into the engine-100m, 01 stokehole
By disconnecting the lever from small cylinder, and connecting duect to
throttle valve, it can be then used as a governor for 1acing or in the event of
the tail shaft breaking, the spring being adjusted to suit
The valve can be actuated either by steam, hydraulic, or vacuum power or be
controlled by electricity
a
1000

page_text: "
manner the same 18 to be performed to be particularly described and ascertained
in and by the following statement in writing -
This invention has reference to an automatically-acting throttle valve, con-
nerted dnect to the mam stop valve on steam boilers, and whereby in the event
of an explosion or steam pipe bursting it will instantly shut off the steam from
boilers
The improvements can also be used as a maine governor to prevent racing
at sea and for shutting off the steam in the event of the tail shaft breaking
And in order that my said invention and the manner of carrying same into
practice may be properly understood I have hereunto appended a sheet of
explanatory drawings, in which Figures 1 and 2 are a sectional side elevation
and plan view respectively illustrating the application of my automatic shut-off
throttle valve Figures 3 and 4 are a detached elevation and plan view respec-
tively of the disc attached to lever And Figures 5 and 6 are elevations at
right angles to each other of the valve chest and lever attachments
Refering to these diawings
According to my improvements I use an ordinary valve chest A with one end
long enough to admit a small steam cylinder I between the centre of chest, and
centre of throttle valve for operating valve E, the end of chest or pipe where
throttle valve is placed being nearest main stop valve on boilers.
In the valve chest A is a moveable disc a which is secured to the end of a
lever by a cottei a³ and keyed on to a shaft in the cover of chest A On the
one end of this shaft there 18 a sping B for adjusting the moveable disc a
to suit the working pressure of boilers, and on the other end of shaft a there is
a level with a moveable catch b¹ working into a toothed rack C for keeping
the disc a from coming back, after an explosion, thereby preventing a fresh outlet
of steam
In the event of a steam pipe bursting, a casing door in the high pressure
cylinder giving way, or a tail shaft breaking, the increased velocity of steam
above to that which the spring B has been set operates the disc a and the slide
valve spindle of cylinder D, with the result that steam being admitted to
cylinder D, its piston through the rod D¹ and lever D shuts the thiottle valve E,
thereby preventing a further inrush of steam into the engine-room or stokehole
A level (from engine-100m connecting to stop catch C¹ 18 for disconnecting
the toothed jack C on sector so that the apparatus can be used then as a manne
governo, the spring B being adjusted to suit the steam pressure
The valve E may be placed on any part of the steam pipe or pipes
The disc may be placed in any position and the slide valve of cylinder or
1ods of throttle valve, connected direct to it, or to a level or levers connected to
disc shaft
The valve can be actuated either by steam, hydraulic, or vacuum power or
be controlled by electricity
The small cylinder D may be placed on any part of the chest, or apart if
required and the slide valve to be operated by either connecting the 1ode to
lever a through a stuffing box in chest, or direct to the lever b Or it can be
used without a cylinder by connecting direct the lever b by a nod to the level
on spindle of valve E
Having now particularly described and ascertained the nature of my said
invention and in what manner the same 18 to be performed, I declare that what
I claim 18.
Fist The arrangement of a moveable disc or equivalent organ in a steam
chest or pipe, controlled by a regulating spring or springs for actuating the
throttle valve in connection with the main stop valve on steam boilers, sub-
stantially as and for the purposes herein described in reference to and shown in
the accompanying diawings
Second A moveable disc attached to a lever within a steam chest or pipe, said

page_text: lever being attached to a spindle fitted with a regulating spring, and having
connections to valve of a steam controlling cylinder for automatically operating
throttle valve, and means for keeping the moveable disc fiom coming back
after an explosion, substantially as and for the purposes herein described in
reference to and shown in the accompanying drawings
Third. The arrangement in combination of appliances for regulating and
automatically operating a throttle valve connected to the main stop valve of
steam boilers, substantially as and for the purposes herein described in reference
to and shown in the accompanying drawings
Datad the lat Lumust 1000
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents