Improvements in Regulating the Admission of Steam to Steam Engines and in Apparatus therefor.
Year: 1892

page_text: Date of Application, 16th Dec., 1892
Complete Specification Left, 18th Sept., 1893-Accepted, 21st Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in Regulating the Admission of Steam to Steam
Engines and in Apparatus therefor.
1, THOMAS MUDD of The Central Marine Engine Works, West Hartlepool in
the County of Durham, Engineer, do hereby declare the nature of this invention
to be as follows:-
I provide steam engines with an initial receiver, or chest which shall have the
function of preventing the first cylinder from being at any time in direct
communication with the boiler or steam pipe. This initial receiver will be a
chest of any form and in point of capacity will be suitably proportioned to that
part of the cylinder capacity known as the "admission capacity." The special
function of this receiver, named above, will be accomplished by fitting to the
chest at its inlet a valve of any known form, (such as a slide, piston, stop, double-
beat, butterfly, or clack valve) which valve will be opened and shut at suitable
times by the engine itself or by some moving part thereof, in such a way as to let
steam into the initial receiver from the boiler when the main valve of the cylinder
is shut, and prevent steam going into the initial receiver when the main valve of
the cylinder is open for admission. The object of this initial receiver with the
special function herein named is to cause the steam to work expansively from the
moment when the piston of the first cylinder commences its stroke, instead of
from the end of admission only, as is usual.
In engines which are required to give out varying power at different times, this
initial receiver may be fitted so that its working capacity may be increased or
diminished at will. One method I propose for effecting this is by making the
whole or part of the initial receiver cylindrical and fitting therein a piston or
disc, with a rod or spindle attached to it and passing through oue end of the
receiver which rod' can, by hand or by a screw or rack or other means, be
pushed in or out so as to set the pistou or disc at any required part of the
receiver. There would be a small opening provided so that steam could pass very
slowly from one side of this disc to the other for the purpose of equalising the
pressure and facilitating the pushing of it into a new position, but this opening
would not be large enough to permit of any appreciable play of steam at every
stroke of the engine from one side of the disc to the other.
In this way the actual working capacity of the initial receiver would be confined
to the space at one side only of the disc. Or, instead of this; two or more initial
receivers could be used coupled up in series or in parallel with the steam pipe
leading to the engine cylinder, and each controlled by a valve.
To prevent loss from condensation in the initial receiver, it may be fitted with a
high pressure steam jacket, or with tubes or coils in which high pressure or super-
heated steam circulates, or be otherwise 'heated.
Deted this 14th day of December 1809

page_text: COMPLETE SPECIFICATION.
Improvements in Regulating the Admission of Steam to Steam
Engines and in Apparatus therefor.
I, THOMAS MUDD, of The Central Marine Engine Works, West Hartlepool in
the County of Durham, 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 :-
I provide steam engines with an initial receiver, or chest which shall have the
function of preventing the first cylinder from being, at any time in direct
communication with the boiler or steam pipe. This initial receiver will be a chest
of any form and in point of capacity will be suitably proportioned to that part of
the cylinder capacity known as the admission capacity.' The special function of
this receiver, named above, will be accomplished by fitting to the chest at its inlet a
valve of any known form (such as a slide, piston, stop, doublebeat, butterfly or clack
valve) which valve will be opened and shut at suitable times by the engine itself
or by some moving part thereof, in such a way as to let steam into the initial
receiver from the boiler when the main valve of the cylinder is shut, and prevent
steam going into the initial receiver when the main valve of the cylinder is open
for admission. The object of this initial receiver with the special function herein
named is to cause the steam to work expansively from the moment when the
piston of the first cylinder commences its stroke instead of from the end of
admission only as is usual.
Figures 1, 2 and 3 of the drawing illustrate this part of my invention.
In these―
a is a steam cylinder, 6 is the valve, c is the initial receiver of carefully regulated
capacity proportionate to the expansion required between admission and cut off,
d is a passage in communication with the main steam pipe and boiler, e is an
additional piece on the slide valve to act as a valve over the inlet to the initial
receiver and which is moved with the main valve by the engine.
In Figure 2, the valve is rising, indicating that the passage from the steam pipe
to an initial receiver is closed by the time the valve opens for steam to the
cylinder at bottom and therefore the admission to cylinder is closed before the
inlet to initial receiver is again opened on the down stroke of the valve.
Figure 3 indicates that the same functions are performed with respect to steam
admission to the top of the cylinder.
In engines which are required to give out varying power at different times, this
initial receiver may be fitted so that its working capacity may be increased or
diminished at will. One method I propose for effecting this is by making the
whole or part of the initial receiver cylindrical and fitting therein a piston or disc
with a rod or spindle attached to it and passing through one end of the receiver,
which rod can, by hand or by a screw or rack or other means, be pushed in or out
so as to set the piston or disc at any required part of the receiver. There would
be a small opening provided so that steam could pass very slowly from one side of
this disc to the other for the purpose of equalising the pressure and facilitating
the pushing of it into a new position, but this opening would not be large enough
to permit of any appreciable play of steam at every stroke of the engine from one
side of the disc to the other..
In this way the actual working capacity of the initial receiver would be confined
to the space at one side only of the disc. Or, instead of this, two or more initial
receivers could be used coupled up in series or in parallel with the steam pipe
leading to the engine cylinder, and each controlled by a valve.
To prevent loss from condensation in the initial receiver, it may be fitted with a
high pressure steam jacket, or with tubes or coils in which high pressure or
superheated steam circulates, or be otherwise heated.

page_text: Figure 4 illustrates this part of my invention; in it a great part of the initial
receiver is a separate vessel f, with piston g, by which the capacity bebind the
piston can be regulated by means of screw or otherwise.
a
i is a valve controlling the inlet to the initial receiver, and it is actuated by
system of rods and levers j from the head of the valve spindle k or otherwise.
The valve opens once for the forward stroke of the engine and once for the
backward stroke, closing the admission to the initial receiver when the admission
to the cylinder is open.
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―
1. The method of regulating the admission of steam to steam engines which
consists in admitting the steam to an initial receiver at a time when said receiver
is cut off from the engine and then admitting it from the receiver to the engine at
the commencement or near the commencement of the stroke, the connection
between the boiler and initial receiver being then closed.
2. The combination with a steam engine of an initial receiver substantially as
described.
3. An initial receiver adjustable in size substantially as and for the purposes
described.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.