Improvements in Throttle Valves for Steam Engine Governors.
Year: 1897

page_text: PROVISIONAL SPECIFICATION,
Improvements in Throttle Valves for Steam Engine Governors.
We, WILLIAM HENRY ALLEN and RICHARD WILLIAM ALLEN, both of Queen's
Engineering Works, Bedford, in the County of Bedford, Engineers, do heroby
declare that:-
-
The object of our invention is to improve the construction of throttle valves by
making them more sensitive to the action of the governor and at the same time
to make them less liable to get out of order.
To do this we construct the throttle valve as follows: —
The outer casing we make preferably of cast-iron, into this casing we fit a gun-
Around and through the
metal liner having one end closed and the other open.
periphery of this liner we drill rows of holes. In the inside of the liner a valve
works in such a manner that in moving up or down the above mentioned holes in
liner are partially or wholly covered. Steam is introduced into the outer casing
and around the outside of the liner, it then passes through the drilled holes on its
way to the engine. In passing through these holes the steam is more or less
throttled by the internal valve, in this manner regulating the quantity which
passes to the engine. The necessary up and down motion in communicated to
the valve by means of a round horizontal spindle which passes through the outer
casing. On this spindle are fixed two levers of about the same length, one on the
inside of the box, the other on the outside. The inside lever is connected to the
valve by means of a link or links in such a way that when the outer lever is moved
up or down, this up or down motion is communicated through the horizontal
spindle to the internal lever and from this lever by means of the link or links to
the valve. By this arrangement the valve is perfectly free to move in any direction
either due to difference of temperature or mechanical fit.
The outside lever derives its motion from the governor to which it is connected
Any suitable manner.
Improvements in Throttle Valves for Steam Engine Governors.
WILLIAM HENRY ALLEN and RICHARD WILLIAM ALLEN, Engineers, of Queen's
Engineering Works, Bedford, 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 our invention is to improve the construction of throttle valves by

page_text: making them more sensitive to the action of the governor and at the same time to
make them less liable to get out of order.
To do this, we construct the throttle valve as follows:
The outer casing we make preferably, of cast-iron, into this casing we fit a gun-
metal liner having one end closed by a loose but steam tight cover. Around and
through the periphery of this liner we drill or form two rows of holes or ports.
In the inside of the finer a valve works in such a manner that in moving up or
down the above mentioned holes or ports in the liner are partially or wholly covered.
Steam is introduced into the outer casing and around the outside of the liner, it
then passes through the holes or ports on its way to the engine.
The steam in passing through these holes or ports is more or less throttled by
the internal valve, in this manner regulating the quantity which passes to the
engine. The necessary up and down motion is communicated to the valve by
means of a round horizontal spindle which passes through the outer casing. On
this spindle are fixed two levers of about the same length, one on the inside of the
box, the other on the outside. The inside lever is connected to the valve by means
of a link or links in such a way that when the outer lever is moved up or down,
this up or down motion is communicated through the horizontal spindle to the
internal lever and from this lever by means of the link or links to the valve.
A very important point in this valve is its segmental structure which enables it
to expand and contract with the changes of temperature it is subjected to in
working without getting distorted or altering its shape.
The outside lever derives its motion from the governor to which it is connected
in a suitable manner.
DESCRIPTION OF DRAWINGS.
Referring to Figures 1 and 2, Fig. 1 is a vertical section through the centre of
the throttle-valve, Fig. 2 a sectional plan on line X X.
2
2
In Figures 1 and 2, A A is the outer-casing which we prefer to make of cast-
iron. B B Figure 1, is the main liner made of gunmetal; it is a plain hollow
cylinder open top and bottom. The top of the liner is closed by a loose, but steam
tight cover C, which is held in position by the spring D and bridge E. Around
and through the periphery of this liner we form two rows of holes as shewn in
the detail at L, Fig. 3, or two rows of ports formed as shewn at K, Fig. 4. In the
inside of the liner B, B, a valve works up and down; this valve is actuated by the
governor and is connected to it by the rod M, Figs. 1 & 2, in a suitable manner. 3
The valve is made in the following manner:-
F, F are plain cylindrical rings which are held in position by the three three-
armed pieces G, G₁ and H. The bolt 1 passes through the centre bosses of the
three pieces G, G' and H, and connects the whole together. A very important
point in this valve is its segmental structure which enables it to expand and con-
tract with the changes of temperature it is subjected to in working without getting
distorted or altering its shape. The liner B, B is also free to expand and contract
with changes of temperature without distortion.
It follows from the above property of free expansion that the valve can work
within the liner with the minimum amount of friction and that its liability to
stick (owing to alterations in shape due to variations of temperature) is reduced
to a minimum. The necessary up and down motion is communicated from the
governor to the valve by the rod M, which is connected to the outside lever O,
Figs. 1 & 2. This lever O is fixed to a round spindle P, which passes through the
bush Q. On the other end of the spindle P the lever N is fixed, which in its turn
is connected to the valve by means of links R and pins S. It will be noticed that
by adopting this method of construction we get a very flexible arrangement and
that any small inaccuracy in the position of the valve and liner will not make the
valve stick while working; nor will it affect the governor. We also make the
rod M of about the same weight as the valve, and as these are placed on opposite
sides of the spindle P, they balance one another.
4

page_text: The working of the throttle valve is as follows:-
Steam enters at the top of the valve-box as shewn by the arrows, Fig. 1, and
surrounds the liner B, B. It then passes through the holes or ports in the liner,
then through the centre of the valve on its way to the engine. In passing through
these holes or ports the steam is more or less throttled by the rings F, Fig. 1, of
the internai valve, in this way regulating the quantity of steam which passes to the
engine. We do not bind ourselves to the exact details as described above.
Having now particularly described and ascertained the nature of our said in-
vention, and in what manner the same is to be performed, we declare that what we
claim is:-
1st. The construction of a throttle-valve box with its valve and liner built-up
in pieces in such a way that whatever the changes of temperature may be they
are free to expand and contract without distortion or change of section, substantially
as described.
2nd. The construction of a throttle valve box with its valve connected to the
governor by means of a horizontal spindle, lever and links, all substantially and for
the purposes described.