Improvements in Hot-air Engines.
Year: 1889

page_text: Date of Application, 8th Jan., 1889
Complete Specification Left, 31st Aug., 1889-Accepted, 12th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Hot-air Engines.
I HORACE ROBINSON 9 Albert Square Manchester Engineer do hereby declare the
nature of this invention to be as follows:-
My invention relates to improvements in the class of air engines in which the air is
alternately heated and cooled and the consequent expansion and contraction is utilised.
to produce motive power, and more particularly is intended to effect improvements
over engines as described in my patent No. 12346 A.D. 1886. The object of this
present invention is to obtain a direct and central connection between the moving
parts and the crank pin and to thus do away with angular or twisting strains and
pressures and consequent friction, and also to produce a simple engine applicable to
small powers such for instance as the driving of ventilating propellers &c. &c. As in
my previous engines an air chamber is used preferably of cylindrical form with its
axis vertical. This chamber may be formed of cast iron and may be cooled either by
a water jacket at its upper end or by the following means-The said chamber may be
extended at its upper end into a platform or table of considerable mass and surface.
This platform or table serves the part of a bed upon which the working cylinder and
the crank shaft bearing or bearings are mounted and at the same time its mass and
surface absorbs and disperses sufficient heat to cool the upper part of the said air
chamber. The working cylinder may be cast with one end closed and the other end
open, and the closed end may have a port or passage cast in it. This port is in free
communication with a port or passage cast or formed in the before mentioned table
or bed or otherwise leading to the said air chamber so that the varying pressure of
the air in the air chamber is free to act upon the piston working in the said cylinder.
Within the air chamber a displacer or regenerator is moved, and this may be formed
either as described in my specification No. 12346. A.D. 1886, or in the following
manner; a number of discs of asbestos may be threaded upon a rod and held fast
together by a metal disc or plate at the top and bottom; the upper one preferably
bearing against a sholder formed upon the said rod and the lower one attached to
the rod by a screw thread or other suitable means. Or a metal cylindrical box may.
be used, cast hollow, of iron or other suitable metal, with suitable holes at its ends to
ventilate the core and after the extraction of the core, soot, slag-wool, or other suitable
nonconductor of heat may be inserted and the holes plugged up, the uper hole may
be plugged up by the insertion of the rod which moves the displacer or regenerator.
This rod extends out of the air chamber into the open air and may be made air-tight
by passing through a long hole in the top of the air chamber, a gland and stuffing
box are thus dispensed with. The said rod is attached by links or a single forked
link to an arm or lever the fulcrum of which is mounted over the before mentioned
working cylinder and this arm is connected to the crank pin by a link on each side or
the equivalent of this so that the strains are central and no twisting strain is thrown
upon the arm or lever. The working piston is connected by a connecting rod to the
crank pin, the said connecting rod is thus brought quite centrally to the crank pin
and has no other office to perform than to transinit the power, and there is thus no
thrust or twist to operate upon the piston other than that caused by the vertical
angularity of the connecting rod. The air chamber is heated at its lower part or end
eithor by a suitable furnace or other means or a metal casing, preferably of cast iron,
may be formed with a hole in it at one side and a chimney or exit at the other, the
said hole is placed in such a position that a gas flame of the Bunsen type is drawn
through it and the flame impinges upon the heater or lower part of the air chamber
to heat it. An annular or suitable space is left round the flame for air to enter to

page_text: support combustion and also to enable the burner to be lighted. The said metal
casing may be lined with asbestos or other nonconductor of heat. When the engine
is required for ventilating, an air propeler may be attached directly upon the engine
shaft. The speed of the engine may be controled in the following manner; a
centrifugal governor, preferably horizontal, driven from the engine shaft, moves a
small spindle and this spindle bears preferably at its end against one arm of a light
bell crank or lever; a weigh is attached to the other arin of this bell crank in such a
manner that it can be moved and set in various positions upon the said arm and thus
more or less counterbalance the centrifugal force of the governor and in this way the
speed of the engine may be adjusted. This bell crank may be attached to the stalk of
a valve, which valve may be of disc form with holes through it which correspond
with holes formed in the valve seat so as to permit the air to escape from the engine
when the governor bails or weights fly outward; these holes however are shut by the
partial rotation of the valve when the centrifugal force of the governor is overpowered
by the before mentioned adjustable weight. The valve may be opened by hand when
it is desired to stop the engine and this may be done by raising the aforesaid weight.
A small chamber may be provided through which the air has to pass in its escape
through the said valve, and this chamber may be filled with cotton waste or other
material through which the air will pass, the object being to subdue the sound of the
escaping air.
Dated this 7th day of January 1889.
HORACE ROBINSON.
.
"
COMPLETE SPECIFICATION.
Improvements in Hot Air Engines.
I HORACE ROBINSON 9 Albert Square Manchester 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 :—
My invention relates to improvements in the class of air engines in which the air
is alternately heated and cooled and the consequent expansion and contraction is
utilised to produce motive power, and more particularly is intended to effect
improvements over engines as described in my patent No. 12346 A.D. 1886. The
object of this present invention is to obtain a direct and central connection between
the moving parts and the crank pin and to thus do away with angular or twisting
strains and pressures and consequent friction; and also to produce a simple engine
applicable to small powers such for instance as the driving of ventilating propellers &c. &c.
As in my previous engines an air chamber is used preferably of cylindrical form with
its axis vertical. This chamber may be formed of cast iron and may be cooled either
by a water jacket at its upper end or by the following means. The said chamber
may be extended at its upper end into a platform or table of considerable mass and
surface. This platform or table serves the part of a bed upon which the working
cylinder and the crank shaft bearing or bearings are mounted and at the same time
its mass and surface, absorbs and disperses sufficient heat to cool the upper part of
the said air chamber. The working cylinder may be cast with one end closed and the
other end open, and the closed end may have a port or passage cast in it. This port
is in free communication with a port or passage cast or formed in the before mentioned
table or bed or otherwise leading to the said air chamber so that the varying pressure
of the air in the air chamber is free to act upon the piston working in the said
cylinder. Within the air chamber a displacer or regenerator is moved, and this, may
be formed either as described in my specification No. 12346. A.D. 1886, or in the
following manner: a number of discs of asbestos may be threaded upon a rod and
held fast together by a metal disc or plate at the top and bottom; the upper one
preferably bearing against a shoulder formed upon the said rod and the lower one
attached to the rod by a screw thread or other suitable mêans. Or a metal cylindrical

page_text: box may be used, cast hollow, of iron or other suitable metal with suitable holes at its
ends to ventilate the core and after the extraction of the core, soot, slag wool or other
suitable nonconductor of heat may be inserted and the holes plugged up, the upper
hole may be plugged up by the insertion of the rod which moves the displacer or
regenerator. This rod extends out of the air chamber into the open air and may be
made air-tight by passing through a long hole in the top of the air-chamber, a gland
and stuffing box are thus dispensed with.
The said rod is attached by links or a single forked link to an arm or lever the
fulcrum of which is mounted over the before mentioned working cylinder and this
arm is connected to the crank pin by a link on each side or the equivalent of this
so that the strains are central and no twisting strain is thrown upon the arm or lever.
The working piston is connected by a connecting rod to the crank pin, the said
connecting rod is thus.brought quite centrally to the crank pin and has no other office
to perform than to transmit the power, and there is thus no thrust or twist to
operate upon the piston other than that caused by the vertical angularity of the
connecting rod. The air chamber is heated at its lower part or end either by a
suitable furnace or other means or a metal casing, preferably of cast iron, may be
formed with a hole in it at one side and a chimney or exit at the other, the said hole
is placed in such a position that a gas flame of the Bunsen type is drawn through it
and the flame impinges upon the heater or lower part of the air chamber to heat it.
An annular or suitable space is left round the flame for air to enter to support
combustion and also to enable the burner to be lighted. The said metal casing may
be lined with asbestos or other nonconductor of heat. When the engine is required
for ventilating, an air propeller may be attached directly upon the engine shaft. The
speed of the engine may be controlled in the following manner; a centrifugal
governor, preferably horizontal, driven from the engine shaft, moves a small spindle
and this spindle bears preferably at its end against one arm of a light bell crank or
lever; a weight is attached to the other arm of this bellcrank in such a manner that
it can be moved and set in various position upon the said arm and thus more or less
counterbalance the centrifugal force of the governor and in this way the speed of the
engine may be adjusted. This bell-crank may be attached to the stalk of a valve,
which valve may be of disc form with holes through it which correspond with holes
formed in the valve scat so as to permit the air to escape from the engine when the
governor balls or weights fly outwards; these holes however are shut by the partial
rotation of the valve when the centrifugal force of the governor is overpowered by
the before mentioned adjustable weight. The valve may be opened by hand when it
is desired to stop the engine and this may be done by raising the aforesaid weight.
A small chamber may be provided through which the air has to pass in its escape
through the said valve and this chamber may be filled with cotton waste or other
material through which the air will pass, the object being to subdue the sound of the
escaping air.
In the accompanying sheet of drawings the same letters are used to denote the
same parts in the different views. Figure 1 is a back elevation of my improved
engine. Fig. 2 is a vertical section through line X X Fig. 1. Fig. 3 is a plan. .
A is the platform or table forming an extension of the air chamber B, this platform
or table serves the part of a bed upon which the working cylinder C and the crank
shaft bearing or bearings D are mounted and at the same time its mass absorbs and
its surfaces disperses away sufficient heat to cool the upper part of the said air
chamber B. The working cylinder C may be cast with one end closed and the other
open, and the closed end may have a port or passage E cast in it. This port or
passage E is in free communication with the port or passage E' cast or formed in the
before mentioned table or platform A leading to the chamber B so that the varying
pressure of the air in the air chamber B is free to act upon the piston F working in
the said cylinder C. G (Fig. 2) is the regenerator formed to work in the air
chamber B and as before mentioned may be similar in construction to that described
in my specification No. 12346. A.D. 1886, namely a metal casing with openings at

page_text: the top and bottom through which the air will pass, this casing being filled with wire
gauze, asbestos yarn, or other suitably perforated material through which the air will
pass. I have found tangled wire to answer well. A displacer may be used as shown
at figure 8 formed of discs of asbestos I and metal plates J, or a cast metal cylindrical
box as shown at Fig. 7, having holes H H formed in it for the extraction of the
core and for filling it with soot, slag wool, or other nonconductor of heat, the
holes H H being plugged up as shown, the regenerator G is however more efficient
in its action. K (Fig. 2 &c.) is the displacer or regenerator rod extending out
into the open air through the hole L L as shown, the hole being so long from L to L
that the rod K works through it practically air tight without the use of packing.
The said rod K is attached by links M. M. (Figs. 2. 3. 5 &c.) or a single forked link
to the arm or lever N the fulcrum of the lever N is at O. The said arm N is
connected to the crank pin P by a link on each side R R (Figs. 2. 3. 4.) so that the
strains are central and no twisting strain is thrown upon the arm or lover N. Fig. 2
shows a side view. Fig. 3 a plan and Fig. 4 a front view of these links. The
working piston F is connected by the rod T (Figs. 2 and 4) to the before mentioned
crank pin P, the said connecting rod T is thus brought quite centrally to the crank
pin P and has no other office to perform than to transmit the power. The air
chamber is heated at its lower part or end either by a furnace or other means or as
shown in Figs. 1 and 2 the casing S (preferably of cast iron) is formed with a hole V
in it at one side and a chimney or exit W at the other, the said hole V is placed in
such a position that a gas flame of the Bunsen type is drawn or enters through it
and the flame impinges upon the heater or lower part of the air chamber to heat it.
The burner V being outside the casing S as before mentioned can be readily lighted.
The burner may be flattened as shown at V1 (Figs. 2 and 6) to spread the flame.
S2 (Fig. 2) is the lining of asbestos or other nonconductor of heat. As before
mentioned the engine is of the type in which the air is alternately heated and cooled
the action of which is as follows as the regenerator or displacer is raised, the air is
heated and expanded and the piston is driven outwards, the regenerator or displacer
now lowered in advance of the piston; its descent cools and contracts the air and
the piston moves inwards; the regenerator or displacer is again raised in advance of
the piston and the cycle is repeated. Figs. 9. 10. 11. 12. 13 show the means of
controlling the speed of the engine and stopping it when required. Fig. 9 is an
elevation showing the centrifugal governor Y, (which may be composed of balls Y'
spring Y2 and driving pulley Ys as shown or otherwise), spindle Y¹ bellcrank or
lever Z, weight and valve stalk Z. Fig. 10 is a vertical section through line QQ
Fig. 9, and section of end of working cylinder C. Fig. 11 is a sectional plan at
line QQ fig. 9. Fig. 12 is an elevation of the valve and Fig. 13 shows more
clearly the valve stalk Z. Z Figs. 9. 10. 11. is the small chamber which is filled
with cotton waste or other material to subdue the sound of the escaping air.
Z (Figs. 10 and 11) are openings in the valve seat corresponding with the holes %
in the valve (Fig. 12). The action is as follows; when the parts are in the position
as shown at Figs. 9. 10. and 11. the valve Z³ is in such a position that the holes % in
it are not over the holes Z in the seat, and therefore the air cannot escape, the
weight Z' tends to keep the valve thus shut. When however the speed of the engine
rises the governor Y moves the small spindle Y¹in the direction of the arrow 2
Figs. 3 and 11. This spindle Y' bears against the short arm Y³ (shown more clearly
Fig. 9) of the bellcrank or lever Z, and this turns the spindle Z to which Z is attached.
The valve Z3 is turned with the spindle and the holes 75 of the valve are brought
more or less over the holes in the valve-seat so that the air escapes and the
pressures behind the piston are thus diminished and the speed of the engine prevented
from rising unduly. The weight Z is also thus raised by the action of the governor
when the speed is highest, when the speed is tending to fall the weight &c. overcome
the tendency of the governor and more or less turn the valve, thus closing it, the
engine thus maintains its speed. To stop the engine when desired the weight 'Z' is
held up and this turns the valve and permits air to escape and the engine stops.

page_text: 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:
First. In an air engine as described and illustrated the platform or table A forming
an extension of the chamber B as shown in figs. 1. 2. and 5. in the accompanying
sheet of drawings, the said platform or table supporting the parts of engine in the
manner shown and acting at the same time as an absorber and disperser of heat as
and for the purpose described and illustrated.
Second. The combination of the platform or table A as and for the purpose
described and illustrated, with the symmetrical arrangement of the connections or
gear of the working parts, this system of connections or gear consisting of the
parts T. R. N. M. K combined as and in the manner described and illustrated.
Third. In an air engine with horizontal cylinder and vertical air chamber and the
other parts also as described and illustrated the simplified construction of the cylinder
having the port or passage E and its end furthest from the crank pin cast in one
piece with it as described and illustrated.
Fourth. The peculiar symmetrical mode of connecting the lever N with the crank
pin P in an air engine as shown, by means of the two links R. R. one being on each
side of the lever N and the connecting rod T embracing the said crank pin P between
the said rods R R as described and illustrated.
Fifth. In an air engine as described and illustrated the special arrangement of the
means for heating the lower part of B in which the casing S with its exit or chimney W
at one sido and hole V at the opposite side is in such a relative position with the gas
flame that the flame and the air to support combustion enter through the said hole V
in the side of the casing S the gas burner V¹ being outside the casing § where it
can be readily lighted, all being as described and illustrated.
Sixth. The peculiar combination of the parts in the air engine governor as
described and illustrated namely the bellcrank or lever Z with the weight the
governor spindle Y' acting upon it the said bellcrank partially rotating the valve Z³
as and for the purpose described and illustrated.
Seventh. The simple form of horizontal cylinder having its end and the passage E
all cast in one piece with it as shown in combination with the moving gear consisting
of the parts T. R. N. M. K. as described and illustrated.
Dated this 30th day of August 1889.
HORACE ROBINSON.