A NEW OR IMPROVED CON- STRUCTION 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 CON-
STRUCTION 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:
In the Specon to my Patent dated 23rd Feb 1884 No 3833 I described a cheap
and simple form of engine worked by steam at a pressure not exceeding that of the
atmosphere. My present invention consists in certain modifications whereby
I simplify and improve the construction and operation of such engines, as I will
describe referring to the accompanying drawings. Fig. 1 is a vertical section of
the engine shewing in addition thereto a water tank U for cooling the condenser
and feeding the boiler, and an arrangement for supplying fuel continuously when
it is desired to avoid stoking the ordinary fire. Fig. 2 is a vertical section through
the feed box and air pump; Fig. 3 is a vertical transverse section through the
cylinder and fire box, and Fig, 4, is a vertical section to an enlarged scale through
the feed box. The engine is generally constructed and arranged as described in
my previous Specification above referred to; I will therefore describe only the
modifications shewn in the drawings.
The cylinder E instead of having its slide S uncovered, has it enclosed in a case
with a lateral orifice O opening into it from the steam space of the boiler. Facing
this orifice is a piston valve worked by a centrifugal governor R so that, as the
speed of the engine increases, the passage of steam through the orifice O becomes
more or less throttled by the advance of the valve v caused by the action of the
governor.
The cross head T by which the piston rod is connected to the connecting rod F,
is made in the form of a hollow cylinder enclosing the joint of the connecting rod
and works within a cylindrical guide t forming part of a bracket which projects
from the boiler.
The condenser K is an upright compartment at the side of the boiler, containing
tubes connecting an upper passage which communicates with the exhaust of the
cylinder E, and a lower passage k' which communicates by a pipe k with the air

page_text: pump P. The compartment K communicates at its top and bottom by pipes u
and u with a water tank U, so that there. is constant circulation of water
condensing the exhaust steam as it descends the condenser tubes from k to k¹.
From the upper part of the condenser K a pipe c³ leads to the feed box W, which
communicates at top and bottom with the boiler, and has a glass front w through
which the water level can be seen.
Within the feed box is a float w' from which is suspended a valve w² imme-
diately under an orifice opening downwards from the pipe ³. According as the
level of the water in the boiler varies, the float w¹ with the valve w² descends or
ascends, opening or closing the orifice of k³ and so admitting the supply of water to
the feed box and boiler, or stopping the supply.
The fire box A and chimney G are arranged as before but, instead of a number
of tubes crossing the chimney, there is a single deep water way H.
The fire may be within the fire box A as before, but when it is desired to avoid
the frequent attention required for stoking, the arrangement shewn in Fig. 1 for
continuous fuel supply may be adopted. In this case the fuel is filled into a
vertical tube X and descends to a space Y, below the floor level, communicating
with the fire box A. The fuel burns in the space Y being supplied with air partly
descending through the fuel in X and partly passing through a grating y.
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
1. For regulating the engine the combination of the governor R, the piston
valve and the orifice O of the slide case S, substantially as herein described.
2. For condensing the exhaust steam, the combination of the compartment K
containing the passages k k' and the tubes connecting them with the water tank U
and its circulating pipes u and u' substantially as herein described.
3. For feeding the boiler, the feed box W and its float and valve in combination
with the feed pipe ka substantially as described.
4. For continuous fuel supply, the vertical fuel tube X, the space Y and grating y
in combination with the fire box A, substantially as described.
5. The construction of Low Pressure engine, combined and operating as berein
described with reference to the accompanying drawings.
Dated this eighteenth day of November 1884.
ABEL & IMRAY,
Agents for the Applicant,
28, Sout ampton Buildings,
London, W.C.