IMPROVEMENTS IN MOTIVE POWER ENGINES AND GENERATORS
Year: 1879

page_text: LETTERS PATENT to Henry Davey, of Clarendon Road, Leeds, in the County
of York, for the Invention of "IMPROVEMENTS IN MOTIVE POWER ENGINES
AND GENERATORS."
Sealed the 19th August 1879, and dated the 3rd March 1879.
PROVISIONAL SPECIFICATION left by the said Henry Davey at the Office of
the Commissioners of Patents on the 3rd March 1879.
HENRY DAVEY, of Clarendon Road, Leeds, in the County of York.
MENTS IN MOTIVE POWER ENGINES AND GENERATORS."
"IMPROVE-
My Invention relates to the construction of motive power engines worked by
fluid pressure in combination with means of generating the working fluid, arranged
in a simple and compact form, and in such a manner as to avoid risk of explosion.
For this purpose I provide a metal casing, preferably of cylindrical form, spreading
out to a greater width at the base, and tapering at the top to form a chimney tube
of smaller diameter, which may be surrounded by a casing containing the feed
water for the engine. The widened part at the bottom constitutes a fire chamber,
which I line with fire-brick or other refractory material, fixing therein a fire grate,
and providing lateral fire and ash doors. From this fire chamber the products of
combustion pass by apertures in the crown of the lining into the upper part of the
casing, which contains a coil or several coils of tube of small diameter bent into
helical form, and occupying the greater part of the space within the casing, so as
to leave only narrow and sub-divided passages for the products of combustion in the
interstices between the convolutions of the coils. This part of the casing is pre-
ferably lined with refractory material to avoid waste of heat. On the outside of
the casing near its top I fix a cylinder fitted with a deep piston, the rod of which
passes through a stuffing box in the bottom of the cylinder, and is linked by a
connecting rod to a crank on a shaft which is mounted in bearings on the lower
part of the casing; thus the casing constitutes the framing of the engine. The
upper end of the cylinder has ports governed by a slide, the jacket of which com-
municates by a pipe with the lowest convolution of the coil, or that part of the
coil which is next the fire chamber. The lower end of the cylinder has passages
fitted respectively with suction and discharge valves. The suction passage has a

page_text: funnel mouth open to the air, into which mouth a stream of water regulated by a
cock or valve is permitted to run. The discharge passage communicates by a pipe
with the highest convolution of the coil, or that part which is farthest from the
fire chamber. The action of the engine is as follows:- The piston in making its
upstroke draws air and water by the suction passage into the cylinder, and by its
downstroke it forces the mixture of air and water into the upper part of the coil.
The mixture in its descent through the convolutions of the coil becomes more and
more heated as it approaches the bottom, whence it finally passes as a mixture of
air and steam to the cylinder, where it effects by its pressure the downstroke of the
piston. There may be two or more cylinders working cranks set at angles on the
same shaft, or when a single cylinder is used the shaft has a fly-wheel of con-
siderable weight to equalise the working force. According to a modified arrangement
the cylinder may be made double acting, a separate pump worked by the engine
being employed to force water alone into the coil. In this case I provide from the
lowest convolution of the coil a passage, fitted with a loaded valve, leading into a
chamber which is in communication with the slide jacket of the engine. The valve
is loaded to a pressure greater than that at which it is desired to work the engine,
and the action is as follows:-The coil being filled with water heated at its lower
part to a high temperature, each stroke of the pump supplying an additional
quantity of cold water causes a corresponding quantity of the heated water to issue
by the loaded valve into the chamber, where it flashes into steam, and whence it
passes to work the engine. The steam chamber is made to extend some depth below
the valve outlet, so as to collect such portions of the water as may not become con-
verted into steam, the water thus collected being drained away through a suitable
stoam trap.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Davey in the Great Seal Patent Office on the 2nd September
1879.
.
HENRY DAVEY, of Clarendon Road, Leeds, in the County of York.
MENTS IN MOTIVE POWER ENGINES AND GENERATORS."
"IMPROVE
My Invention relates to the construction of motive power engines worked by
fluid pressure in combination with means of generating the working fluid, arranged
in a simple and compact form, and in such a manner as to avoid risk of explosion.
For this purpose I provide a metal casing, preferably of cylindrical form, spreading
out to a greater width at the base, and tapering at the top to form a chimney tube
of smaller diameter, which may be surrounded by a casing containing the feed
water for the engine. The widened part at the bottom constitutes a fire chamber,
which I line with fire brick or other refractory material, fixing therein a fire grate,
and providing lateral fire and ash doors. From this fire chamber the products of
combustion pass by apertures in the crown of the lining into the upper part of the
casing, which contains a coil or several coils of tube of small diameter bent into
helical form, and occupying the greater part of the space within the casing, so as
to leave only narrow and subdivided passages for the products of combustion in the
interstices between the convolutions of the coils. This part of the casing is pre-
ferably lined with refractory material to avoid waste of heat. On the outside of
the casing near its top I fix a cylinder fitted with a deep piston, the rod of which
passes through a stuffing box in the bottom of the cylinder, and is linked by a
connecting rod to a crank on a shaft which is mounted in bearings on the lower
part of the casing; thus the casing constitutes the framing of the engine. The
upper end of the cylinder has ports governed by a slide, the jacket of which com-
municates by a pipe with the lowest convolution of the coil, or that part of tho
coil which is next the fire chamber. The lower end of the cylinder has passages
fitted respectively with suction and discharge valves. The suction passage has a
funnel mouth open to the air, into which mouth a stream of water regulated by a
cock or valve is permitted to run. The discharge passage communicates by a pipe
with the highest convolution of the coil, or that part which is farthest from the
fire chamber. The action of the engine is as follows:-The piston in making its
upstroke draws air and water by the suction passage into the cylinder, and by its
downstroke it forces the mixture of air and water into the upper part of the coil.
The mixture in its descent through the convolutions of the coil becomes more and
more heated as it approaches the bottom, whence it finally passes as a mixture of
air and steam to the cylinder, where it effects by its pressure the downstroke of the
piston. There may be two or more cylinders working cranks set at angles on the
same shaft, or when a single cylinder is used the shaft has a fly wheel of con-
siderable weight to equalise the working force. According to a modified arrangement
the cylinder may be made double acting, a separate pump worked by the engine
being employed to force water alone into the coil. In this case I provide from the
lowest convolution of the coil a passage, fitted with a loaded valve, leading into a
chamber which is in communication with the slide jacket of the engine. The valve
is loaded to a pressure greater than that at which it is desired to work the engine,
and the action is as follows:-The coil being filled with water heated at its lower
part to a high temperature, each stroke of the pump supplying an additional
quantity of cold water causes a corresponding quantity of the heated water to issue
by the loaded valve into the chamber, where it flashes into steam, and whence it
passes to work the engine. The steam chamber is made to extend some depth below
the valve outlet, so as to collect such portions of the water as may not become con-
verted into steam, the water thus collected being drained away through a suitablo
steam trap.

page_text: Fig. 1 is a vertical section of a generator with a side elevation of an engine
according to my Invention; Fig. 2 is a side view of the generator with the engine
partly in section; and Figure 3 is a sectional plan through the engine cylinder and
the upper part of the generator. A, the engine cylinder, is fitted with a deep
piston B, which is connected by a connecting rod b to a crank on the shaft C, which
carries a heavy fly-wheel c. An eccentric on the shaft C works a slide D, which
governs an eduction passage and a port leading into the upper end of the cylinder A.
The lower end of the cylinder forms a feed pump, provided with a suction valve a¹
and a discharge valve a². Above the suction valve a¹ is a funnel mouth, into which
feed water, determined in quantity by a cock e, flows from a reservoir E surrounding
the chimney. At every upstroke of the piston B the feed water is drawn into the
cylinder along with a quantity of air; and in order to prevent leakage of the water
during the downstroke of the piston a boss a³ projects some distance up from the
cylinder cover, the piston being hollowed out on its underside to receive it. From
the discharge valve as leads a pipe F, which is bent into a number of convolutions
forming a coil extending down within a casing G lined with fire clay g. From the
lowest convolution of the coil F a pipe H ascends inside the coil, and leads into a
short coil in the upper part of the casing, communicating with the jacket of the
slide D and a spring safety valve h³. From the eduction port of the slide a pipe d
leads into the chimney. Below the casing G is a fire place I, for which may be
substituted a set of gas or oil burners, and in the middle of the coil F hangs a
baffle lump K, which causes the products of combustion to pass up the annular
space containing the convolutions of the coil, and serves also as a reservoir of heat.
From this space the products pass away by the chimney L, which is surrounded by
a casing E containing the feedwater. At every upstroke of the piston B a certain
quantity of water, as determined by the cock c, along with air is drawn into the
lower end of the cylinder through the suction valve a¹. By the downstroke this
charge of air and water is driven through the discharge valve a³ in the form of fine
spray into the coil F, which it descends, becoming more and more heated as it
approaches the fire or burners, the water being converted into steam. The mixture
of heated air and steam ascends the pipe H, and after passing through the upper
coil h, in which the steam becomes dried or superheated, it passes to the upper end
of the cylinder, where it acts as working fluid, propelling the piston B. After per-
forming work the exhaust is discharged by the pipe d up the chimney L. The
quantity of air sent with the water into the generator by the downstroke of the
piston may be reduced by providing an escape hole through the side of the cylinder
at a certain height from the bottom, so that until the piston in its descent passes
this hole no compression of the air takes place. The cock e which determines the
amount of food water may be set by hand according to the power required. It may
also be regulated by a governor of any known kind, so as to vary the supply
according to the speed of the engine. Fig. 4 shews partly in section a modified
arrangement, in which the cylinder is double acting, and the feed of water and air
is effected by a pump M worked by gearing m at half the speed of the engine, so
that each charge delivered from the pump into the coil F works four successive
strokes of the piston. Fig. 5 is a longitudinal section; Fig. 6, a transverse section;
and Fig. 7, a sectional plan of two cylinders, A¹ single acting and feeding, and A³
double acting, in combination with a zig-zag arrangement of the generating pipe F
within a flue through which the products of combustion from a fire I pass on their
way to the chimney L. Figs. 8 and 9 are side and end views partly in section,
and Fig. 10 a sectional plan of a pair of engines with generator applied as a fire
engine, each piston working a pump N. In this case, as in the former, one of the
cylinders is double acting whilst the other operates for feeding, as described with

page_text: reference to Figs. 1, 2, and 3. The parts shewn in Figs. 8, 9, and 10, as well as in
Figs. 4 to 7 inclusive, being marked by the same letters as the corresponding parts
described with reference to Figs. 1, 2, and 3, it will be understood that the same
description applies to them.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,―
First. The construction of motive power engine and generator, wherein a piston
moving in a cylinder makes a stroke drawing into the cylinder a charge of water
and air, and by its back or working stroke forces this charge in the form of spray
into a heated coil or congeries of pipes, whence the mixture of steam and hot air
passes to the cylinder and effects the working stroke of the piston therein, substan-
tially as described with reference to Figs. 1, 2, and 3, and partly to 5, 6, and 7, and
to Figs. 8, 9, and 10 of the accompanying Drawings.
Second. In motive power engines and generators of the kind referred to in the
preceding claim, so arranging the coil or congeries of heated pipes and the con-
nections to and from them that the charge is forced into the coolest part and issues
from the hottest part, as and for the purposes herein set forth.
In witness whereof, I, the said Henry Davey, have hereunto set my hand and
seal, this Twenty-sixth day of August, in the year of our Lord One thousand
eight hundred and seventy-nine.