A HOT-AIR MOTOR ENGINE
Year: 1884

page_text: I, HENRY PERCY HOLT, of Openshaw, Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of my invention for "A HOT-AIR MOTOR
ENGINE" to be as follows:-
This invention relates to a construction and arrangement of hot air motor
engine in the following manner :-
:-
A vertical cylinder is made in two parts, an upper part in which the piston works,
kept cool by a water casing, and a lower part which is attached to the upper part
with non-conducting material interposed between their flanges. In this lower part,
which is kept heated by a fire or flame, there is presented a large extent of heating
surface, and from this lower part there is an exhaust passage leading to a lateral
port opening into the cool port of the cylinder, above which port there is another.
port leading to a discharge pipe. The cylinder has also a third lateral port for
admission of cold air, this port being at a lower level than those above mentioned.
The piston is made of considerable depth, and has formed in its side a D-hollow
which, at a certain part of the stroke, puts the two lateral exhaust ports in
communication with each other.
The piston is connected in the usual way to a crank on a flywheel shaft, and the
operation of the engine is as follows: When the piston is approaching the upper
extreme of its stroke, there being at that time reduced pressure in the cylinder
under it, the inlet port is uncovered and cold air enters below the piston. As the
piston descends, it forces this air down to the heated compartment, from which a
portion of the hot air previously contained in it is expelled by the exhaust ports
and the D-hollow of the piston as it passes them. The cold air thus transferred to
the hot compartment, having its pressure and volume increased, propels the piston
upwards. As the piston ascends, a portion of the hot air escapes by the exhaust
ports, and afterwards, by the continued ascent of the piston, the pressure under it
is reduced until the inlet port is again opened for admission of fresh cold air. The
hot air discharged by the exhaust pipe may be employed to supply the fire or flame
that heats the lower compartment of the cylinder.

page_text: Although, in order to simplify explanation, I have described a vertical engine, it
may have its cylinder horizontal or inclined.
The speed of the engine may be regulated by a governor arranged to open more
or less a valve allowing a portion of the working charge to escape from the
cylinder.
c
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.
I, HENRY PERCY HOLT, of Openshaw, Manchester, in the County of Lancaster
Engineer, do hereby declare the nature of my invention for "A HOT-AIR MOTOR
ENGINE and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
This invention relates to a construction and arrangement of hot air motor engine
as I will describe referring to Fig. 1 which is a vertical section and Fig. 2 which is
a plan of an engine according to my invention.
A vertical cylinder is made in two parts, an upper part A in which the piston B
works, kept cool by a water casing C and a lower part D which is attached to the
upper part with non-conducting material interposed between their flanges-In this
lower part, which is kept heated by a fire or flame as from a fire box E there is
presented a large extent of heating surface which may be arranged as shewn in
the sectional plan Fig. 3. From this lower part D there is an exhaust passage F
leading to a lateral port opening into the cool port of the cylinder, above which
port there is another port leading to a discharge pipe G. The cylinder has also
a third lateral port H for admission of cold air, this port being at a lower level
than those above mentioned. The piston B is made of considerable depth and has
formed in its side a D-hollow K which, at a certain part of the stroke, puts the two
lateral exhaust ports F and G in communication with each other.
The piston is connected in the usual way to a crank L on a flywheel shaft, and
the operation of the engine is as follows: When the piston B is approaching the
upper extreme of its stroke, there being at that time reduced pressure in the
cylinder under it, the inlet port H is uncovered and cold air enters below the
piston. As the piston descends, it forces this air down to the heated com-
partment D from which a portion of the hot air previously contained in it is

page_text: expelled by the exhaust ports F and G and the D-hollow K of the piston as it
passes them. The cold air thus transferred to the hot compartment, having its
pressure and volume increased, propels the piston upwards. As the piston ascends,
a portion of the hot air escapes by the exhaust ports F and G and afterwards, by
the continued ascent of the piston, the pressure under it is reduced until the inlet
port H is again opened for admission of fresh cold air. The hot air discharged by
the exhaust pipe may be employed to supply the fire or flame that heats the lower
compartment of the cylinder, for which purpose it may be conducted by a pipe M
into the ashpit of the furnace E.
Although, in order to simplify explanation, I have described a vertical engine, it
may have its cylinders horizontal or inclined."
The speed of the engine may be regulated by a governor arranged to open more
or less a valve allowing a portion of the working charge to escape from the
cylinder.
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 hot air motor engine wherein a piston working in a cylinder
governs ports, one for admission of cold air which by the movement of the piston
is transferred to a hot part of the cylinder, and others for discharge of hot air after
performing work in the cylinder, substantially as herein described with reference
to the accompanying drawings.