A NEW OR IMPROVED CONSTRUCTION OF LOW PRESSURE STEAM MOTOR
Year: 1884

page_text: I, HENRY DAVEY of Headingley, Leeds, in the County of York, Engineer,
do hereby declare the nature of my Invention for "A NEW OR IMPROVED
CONSTRUCTION OF LOW PRESSURE STEAM MOTOR," to be as follows:-
My Invention relates to a cheap and simple construction of steam motor,
applicable where small power is required. This motor being worked by steam at a
pressure not exceeding that of the atmosphere, the boiler is of a simple character;
open at top, requiring no safety valve gauges or appliances for feeding against
pressure, and safe from all risk of explosion. The exhaust steam is condensed
either by injection or surface condensation, and the condenser is in communication
with the boiler, so that the level of water in the boiler is automatically maintained.
The form of engine which I adopt for simplicity of construction is of the following
kind. An upright cast iron vessel is divided by a partition into two compartments,
the front compartment being the boiler, and the back compartment the condenser.
These compartments may, however, be formed in separate vessels. The lower part
of the boiler projects forwards giving space within it for the fire box, and forming
a support for the bearings of the crank shaft. The upper part also projects so as to
give a steam space, within which the cylinder is placed. The piston rod extends
down through the cylinder bottom and is linked by a connecting rod to the crank
below. A flue tube extends from the firebox up through the body of the boiler and
steamspace, superheating the steam, or there may be several such tubes. The
steamspace communicates with the chimney above by a narrow passage around the
flue tube, so that the pressure can never exceed that of the atmosphere. The
condenser is preferably of the surface kind, consisting of tubes extending down
through the condenser compartment, these tubes being surrounded by water, from
the upper level of which the boiler is fed by a small passage. At the bottom is a
small air pump, which is worked by a crank pin or eccentric on the flywheel shaft,
and discharges into the boiler. A governor of any known kind may be applied to
regulate the engine either by working a valve admitting more or less air into the
condenser so as to reduce the vacuum, or by working a damper checking more or
less the air supply to the fire, or by both actions.
Dated this 22rd dose of 100%
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings, London, W.C.

page_text: I, HENRY DAVEY of Headingley, Leeds in the County of York, Engineer,
do hereby declare the nature of my Invention for "A NEW OR IMPROVED
CONSTRUCTION OF LOW PRESSURE STEAM MOTOR" and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :----
My Invention relates to a cheap and simple construction of steam motor
applicable where small power is required. This motor being worked by steam at a
pressure not exceeding that of the atmosphere, the boiler is of a simple character,
requiring no loaded safety valve, gauges or appliances for feeding against pressure,
and safe from all risk of explosion. The exhaust steam is condensed, it may be by
surface condensation, but when the greatest simplicity is required, it is condensed
by injection. I will describe the engine referring to the accompanying Drawings.
Fig. 1 is a vertical section through the boiler and cylinder, Fig. 2 is a vertical
pection through the condenser and air pump which are situated at one side of the
boiler, and Fig. 3 is a front view shewing the fire place and cylinder in section.
A is the fire box within the boiler B which is an upright cast iron vessel projecting
forwards at the bottom to give space for the fire box A and to carry the bearings
for the crank shaft C on which at one side of the boiler is the flywheel D. The
upper part of the boiler also projects forwards accommodating within it the
cylinder E. The piston rod extends down through the cylinder bottom and is
From the fire box A
linked by the connecting rod F to the crank on the shaft C.
a flue tube G extends up through the body of the boiler and its steam space, and in
order to increase the heating power, water tubes H may be fixed across the flue.
K is the condenser which is a vertical tube placed at the side of the boiler to which
it is fixed. At the top. it receives the exhaust steam from the cylinder by a
branch L, which may have a cock or valve, as shewn, to regulate the speed of the
engine by more or less throttling the exhaust. A pipe M from a cistern a little
higher than the water level in the boiler supplies an injection branch I opening
into the condenser and a feed branch N opening into a vertical tube U which
communicates with the steam and water spaces of the boiler as shewn in the
transverse section Fig. 4. The feed branch has an opening fitted with a conical
plug which is attached to a float W. The water in the tube U maintains the
same level as that in the boiler but is quiescent, and the float W by raising or
lowering the plug V regulates the feed so as to maintain the water at its proper
level.
P is a small air pump worked by a crank pin on the fly wheel shaft. This pump
draws air and water from the condenser and discharges the water into a well from
which there is a lateral outlet G. The pump valves are preferably made as shewn
so that both can be lifted out when required. By a hole p water from the well
enters the pump to keep the plunger lubricated and sealed against suction of air.
The slide S of the cylinder E is worked directly from an eccentric on the fly
wheel shaft. Above the cylinder is a light safety valve X which is not intended
to be loaded, as the construction of the boiler and the jointing to it of the fire box
and flue are, for the sake of simplicity, done in such a way as not to be suited for
high pressures. The cylinder Ê is preferably made of gun metal so as not to
require lubrication of its piston.

page_text: Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:
The construction of low pressure steam motor substantially as described and
represented by the accompanying Drawings.
>
Dated this 16th day of June 1884.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings, London, W.C.