IMPROVEMENTS IN CALORIC ENGINES
Year: 1883

page_text: LETTERS PATENT to Charles Ingrey of Oak House, Fulham, in the County
of Middlesex, Engineer for an Invention of IMPROVEMENTS IN CALORIC
ENGINES
PROVISIONAL SPECIFICATION left by the said Charles Ingrey at the Office
of the Commissioners of Patents on the 6th June 1883.
"
CHARLES INGREY of Oak House, Fulham in the County of Middlesex, Engineer,
IMPROVEMENTS IN CALORIC ENGINES "
My invention has reference to caloric engines of the kind wherein compressed
air is forced into a closed vessel retort or generator containing fuel, and after being
used therein to promote combustion of such fuel is employed to operate the piston
of the engine.
Also
In engines of this kind as heretofore usually constructed it has been found that
at starting the hot air is condensed by contact with the cold surfaces of the
cylinder of the engine, and that consequently until the cylinder becomes heated
the engine is difficult to start and is incapable of developing its full power
with such engines there is considerable radiation of heat from the retort or
generator, and the escape of heat not only causes inconvenience when the engine is
confined in an engine house, but also involves loss of power.
Furthermore there is usually considerable noise in the working of engines
such as above referred to and by reason of their arrangement and numerous parts
they are uncertain in their action and liable to become deranged.
Now my invention is designed to obviate or mitigate the above mentioned
defects, and otherwise to improve the construction and operation of engines of the
kind in question; and is applicable to caloric engines such as described in the
specification of Letters Patent N° 4413 A D 1876 granted to John and William
Thomas Buckett, and N° 2075 AD 1882 granted to John Buckett, as also to other
similar caloric engines.
To accelerate the starting of the engine I provide in connection with the
working cylinder (or cylinders) a space or chamber (or spaces or chambers) into
and through which the whole or a portion of the products of combustion can be
caused to pass or circulate during the time or a part of the time that the fire in
the retort or generator is burning up. The said space or chamber is formed with
or has attached to it an inlet and an outlet to which can be connected pipes or
[Price 1

page_text: channels for conveying the said products of combustion. When the fire is lighted
in the retort or generator atmospheric air is admitted beneath the fuel and a
chimney or flue is used above the fire to create a draught. The space or chamber
in connection with the working cylinder of the engine is arranged intermediately
between the retort or generator, and the chimney, so that the products of
combustion pass into the said space or chamber before issuing from the chimney,
and give up a portion of their heat to the cylinder, which thereby becomes
sufficiently heated to prevent rapid condensation in it of the hot air admitted
thereto on starting the engine.
In some cases instead of using the space or chamber only whilst the fire is
burning up, I arrange the connections with the retort or generator in such a
manner that the products of combustion or hot air will continue to enter the said
space or chamber during the working of the engine.
According to another part of my invention the retort or generator is wholly
or partially surrounded with a jacket or outer chamber into which the cold air
from the pump or pumps is caused to pass before entering the generator, so as to
have its temperature raised by heat which in engines of this kind as usually
constructed is lost by radiation as already explained.
In order to lessen the noise arising from the working of the engine and with
a view to greater certainty and effectiveness of action I provide in lieu of the
ordinary inlet valves for the air pump, a sliding part or valve so formed and
arranged that the pressure of air from within the pump serves to keep the said
sliding part or valve tight against its working face or surface. The sliding part
or valve is operated by an eccentric cam, or other equivalent motion, the
arrangement being such as not to require a stuffing box, and the air inlet to the
pump is constructed to receive a connecting pipe whereby the supply of air may
be drawn from the outside of the engine house.
For the purpose of also dispensing with the usual form of air delivery valve,
I make the sliding part or valve in such a manner that in one position atmospheric
air is free to be drawn in by the pump; in another position the air inlet is closed;
and in a third position the outlet is opened and the compressed air is free to be
delivered by the action of the pump piston. To accomplish this I provide a casing
or jacket which encloses a port or ports in the cylinder, and construct the sliding
part or valve with a passage or chamber, or passages or chambers through which
the air can be drawn, or the compressed air delivered-the said sliding part or
valve is operated by a cam or its equivalent the action of which is in the first
place to open the connexion with the outside air. When the piston of the pump
has arrived at the end of its backward stroke the sliding part or valve is moved
so that the suction is stopped, and the port remains covered, the air is therefore
enclosed in the pump and is compressed therein by the forward stroke of the pump
piston. In connexion with the sliding part or valve I arrange a piston or diaphragm
one side of which is exposed to the pressure of the air in the generator, the other
side being exposed to the pressure within the pump, when therefore the air is
compressed in the pump to a sufficient pressure the piston or diaphragm is caused
to move the sliding part or valve into such a position as to open a way for the
compressed air to the retort or generator. When the pump piston has delivered
the charge of compressed air to the generator the valve or sliding part is returned
to its first position and the next stroke of the pump piston takes in a supply of
atmospheric air.
Another part of my invention relates to slide valves for admitting the hot air
to the cylinder from the retort and discharging it from the cylinder after it has
performed its work upon the piston.
With such slide valves as heretofore usually employed difficulty has been
experienced owing to the great heat to which they are subjected rendering it
impracticable to keep them efficiently lubricated.
Now I have discovered that this is obviated by the use of plumbago in the
formation of the valve or of the face or surface on which it slides

page_text: According to one arrangement I use a valve of plumbago surrounded by a
metallic strap attached to the valve rod.
As the products of combustion pass from the generator to the cylinder they
sometimes carry which them grit or dust which moving at a considerable velocity
would be liable to act after the manner of a sand blast upon the plumbago. To
obviate this I provide a lip or part of metal, such as iron, so arranged as to protect
the plumbago and to be kept lubricated by it. This part of my invention may be
applied in connection with valves of various constructions for the purposes set
forth.
Another part of my invention has reference to an automatic arrangement by
which the governor of the engine is made to control the admission of air to the
generator, in such a manner that when the engine exceeds the normal speed the
compressed air from the pump or pumps or some of it is caused to pass into a
receiver or accumulator instead of into the retort or generator. To this end I
provide a chamber or casing in connection by suitable passages with the pump or
pumps, with the retort, and with an accumulator. Within this chamber or casing
is a valve (or valves) connected to a diaphragm so that the valve (or valves) may
be opened against the pressure of air obtaining in the pump and receiver. The
aren of the diaphragm exceeds that of the valve or valves, and the arrangement is
such that on compressed air being admitted to one side of the diaphragm it will
open the valve or valves-and in connection with the pipe that conveys compressed
air to the diaphragm I provide a small valve or cock and connect it with the
governor of the engine-this valve or cock is so formed that when it has cut off
the supply of compressed air to the diaphragm the air which had previously been:
supplied thereto is free to escape.
When the speed of the engine increases the governor opens the sinall valve or
cock whereupon air from the diaphragm escapes and the valve or valves in the
casing or chamber is or are closed or partially so,-thus the air from the pump or
pumps, or some of it, instead of being delivered to the retort or generator is forced
into the receiver. When the speed of the engine falls below the normal rate the
governor causes the small cock or valve to be closed to the atmosphere, and opened.
to the supply of compressed air and the diaphragm, whereupon the valve or
valves is or are opened and the air from the pump or pumps is delivered to the
generator.
In lieu of the above described arrangement I may cause the valve or valves to
be opened by the pressure of compressed air from the pump and to be closed by
the action of the diaphragm.
Another part of my invention has for object to enable the governor of the engine
to alter the period of "cut off" to the working cylinder. For this purpose I
provide a sliding or reciprocating or rocking plate lever or frame, having a groove
or projection in the form of a cam path. The sliding or rocking movement is
produced by any convenient motion and when in one direction opens the valve
that admits motive fluid to the working cylinder, whereas in the other direction it
closes; the period of closing being sooner or later according to the position of a
movable portion of the cam path, which portion can be moved by the operation of
the governor. When the speed of the engine increases the governor causes the
movable portion of the cam path to assume such a position that the inlet valve is
closed sooner, and the supply of motive fluid to the working cylinder is stopped at
an earlier part of the piston's stroke. When the speed of the engine decreases the
governor alters the position of the movable portion of the cam path so that the
said valve is kept open for a longer period.
Lastly my invention relates to an improved arrangement of caloric engine
wherein the pump is contained within the working cylinder and the pump piston
s connected to and moves with the piston of the working cylinder

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Ingrey in the Great Seal Patent Office on the
6th December 1883.
CHARLES INGREY of Oak House, Fulham, in the County of Middlesex, Engineer.
IMPROVEMENTS IN CALORIC ENGINES
My invention has reference to caloric engines of the kind wherein compressed
air is forced into a closed vessel, retort, or generator containing fuel, and after
being used therein to promote combustion of such fuel, is employed to operate the
piston of the engine.
In engines of this kind as heretofore usually constructed it has been found that
at starting the hot air is condensed by contact with the cold surfaces of the cylinder
of the engine, and that consequently until the cylinder becomes heated the engine
is difficult to start, and is incapable of developing its full power. Now, in order to
obviate or mitigate the above mentioned defects, I provide special means whereby
the products of combustion developed during the burning up of the fire are
utilized to heat the cylinder before introduction of hot air into it from the
generator.
In the accompanying drawings, Fig 1 illustrates in elevation the application to
a vertical engine of means for heating the cylinder according to my invention.
Fig 2 is a plan of the same.
a is the generator or retort of the engine,-b is an outlet for the purpose of
The bed
carrying off the products of combustion whilst the fire is burning up.
plate c of the engine is formed with a space or chamber e having a dividing plate
or baffler d. The said space or chamber e is covered by the bottom of the engine
cylinder f. The space on one side of the dividing plate d communicates with the
downtake pipe g, whereas the space at the other side communicates with the
uptake pipe h. The products of combustion pass from the opening b into the
pipe g which is enclosed within the pipe h and serves to heat the air contained in
the latter, and thereby to induce a draught. The heated products after passing
down the pipe g enter the chamber e where they are caused by the dividing plate
or baffler à to take the direction indicated by the arrows, and to ultimately escape
by the uptake pipe h. A portion of the heat from the products of combustion is
thus transmitted to the cylinder whilst the fire is burning up, so that when the
opening is closed and the retort a is thereby hermetically sealed, the cylinder
will be already heated and the operation of starting will thus be facilitated.
Fig. 3 illustrates another arrangement.. In this case the products of combustion
pass from the generator a into the connecting pipe b and thence into the space or
chamber c which surrounds the cylinder d. Whilst the fire in the generator a is
burning up the door e is removed, and a pipe or chimney fis placed over the
opening g so that the products of combustion in their passage through the space
or chamber c will cause the cylinder to become heated in the manner desired for
the purpose mentioned.
Fig 4 illustrates the application to a horizontal caloric engine of means according
to my invention for heating the cylinder. The products of combustion from the
generator a pass from the opening b into pipe c whence they descend and enter a
chamber d formed at the back of the engine cylinder e.
From the chamber d the
products of combustion ascend through the uptake pipe or chimney f. To prevent
or lessen the loss due to radiation of heat from the generator, I surround or
partially surround the generator with a jacket or an outer chamber into which the
cold air from the pump or pumps is caused to pass before entering the generator.
An arrangement for this purpose is shewn in Figs 5 and 6 in which a is the
generator, b is a fire clay lining,-
―c is an annular space surrounding the said fire

page_text: clay lining, and d is the outer shell of the generator. This shell is separated from
the annular space c by a division d' which forms an annular chamber e into which
the air from the pump or pumps is caused to enter and circulate before entering the
generator. By this arrangement the temperature of the air is raised by heat
which, in engines of this kind as usually constructed, is lost by radiation.
In order to lessen the noise arising from the working of the engine, and to
render its action more certain and effective, I dispense with the ordinary inlet
valves for the air pump, and in lieu thereof I provide an arrangement such as I will
now describe with reference to Figs 7 and 8 of the drawings. In these figures the
pump cylinder a is provided with an inlet port b over which can move a sliding
part or valve c, which is operated through the connecting rod d by an eccentric, or
a cam, or a crank, or other equivalent motion. The air pressure within the pump
tends to press the sliding valve c against the working surface e, so that whilst the
piston f of the pump is compressing the air in the pump the valve c by covering
the opening g prevents leakage. In the position shewn in the figures the piston f
is about to commence its return stroke, and to draw in air through the port b and
opening g as shewn by the arrow. As the piston travels the slide valve c will also
travel until the port bis completely uncovered, whereupon the slide valve c will
commence to return, and by the time the piston f has terminated its return stroke,
and is about to commence its next forward stroke, the port b will be completely
closed. The valve cover is provided with a pipe or branch h to which may be
attached a pipe whereby the supply of air may be drawn from the outside of the
engine house. With the arrangement just described the delivery of compressed air
is made through a delivery valve of ordinary description and the use of a stuffing
box for the valve rod is dispensed with.
$
In some cases I dispense with the ordinary form of delivery valve and I make
the sliding part or valve in such a manner that in one position of it, atmospheric
air is free to be drawn in by the pump, in another position of the valve the air
inlet is closed, and, in a third position of the valve, the outlet is opened and
the compressed air is free to be delivered by the action of the pump piston.
The method by which I accomplish this is illustrated by Figs 9, 10 and 11. a is
the pump cylinder a slide valve,-c cylinder port, and d a suction port. The
slide valve b is operated by a rod e moved by a cam or similar motion so arranged
that it can mechanically move the valve into two positions, and is free to allow the
said valve to be moved (by the piston g) into a third position as follows:-The
valve bis connected by a rod j to a small piston working within a cylinder 7.
This cylinder is in connection with the pump cylinder a by a small pipe m. In
the position shewn in Fig 9 the pump piston al is in the act of making its back-
ward stroke, and is drawing in a supply of atmospheric air. When the piston a'
of the pump has arrived at the end of its backward stroke, the valve 6 will be
mechanically moved so that communication with the suction port will be stopped
and the cylinder port c will be closed. This position is clearly shewn in Fig 10.
The air is thus enclosed within the pump and is compressed by the action of the
piston a. It will be observed that one end of the small cylinder is open, so that
the back of the small piston k is exposed to the full pressure of air from the
generator. The front of the small piston is exposed to the pressure of air within
the pump, by reason of the connecting pipe m. When, therefore, the pressure
within the pump becomes greater than the pressure in the generator, the excess of
force applied to the front of the small piston causes the valve to be moved over
into the position indicated in Fig 11, whereupon the compressed air is delivered to
the generator as shewn by arrows. When the piston a' has completed its forward
stroke and delivered all the air it has compressed, the valve 6 is mechanically
moved to its first position (see Fig 9) and the next stroke of the pump piston
takes in a supply of atmospheric air as before.
Another part of my invention relates to slide valves for admitting the hot air
from the generator or retort to the cylinder, and discharging it from the cylinder
after it has performed its work upon the piston. With such slide valves as

page_text: heretofore usually employed, difficulty has been experienced because the great heat
to which such valves are subjected renders it impracticable to keep them efficiently
lubricated. Now I have discovered that this is obviated by the use of plumbago
in the formation of the valve, or of the face or surface on which it slides.
According to one arrangement I use a valve of plumbago surrounded by a
metallic strap attached to the valve rod.
Figs 12 and 13 illustrate the application of such a valve to the cylinder of a
caloric engine. a is the cylinder, 6 the slide valve, c the metallic strap, and d the
valve rod. e is a port communicating with the cylinder. f is a port communi-
cating with the retort or generator, and g is the exhaust port. h is an inlet
through which the compressed air from the air pump is admitted to the valve
chamber whence it proceeds by ¹ to the generator. The pressure of air in the
valve chamber serves to keep the slide valve b against the face of the ports, and at
the same time prevents undue heating of the valve and consequent loss of heat by
radiation, whilst the air becomes warmed before entering the generator.
Fig 14 illustrates the application of a plumbago slide valve to a double acting
engine.
Fig 15 shews an arrangement wherein the motive fluid passes from the generator
to the cylinder through a passage formed in the plumbago valve. a is the cylinder,
the plumbago valve, the exhaust port, and d the inlet port. The heated
motive fluid (products of combustion) passes from the generator e by the branch f,
and when the port g in the slide valve bis over the inlet port d, the said motive
fluid enters the cylinder and operates the piston as will be readily understood.
In Fig 15 the valve is shewn in the position of "cut off." The plumbago valve b
is attached to the slide rod h by a metallic strap j, and leakage between the end of
the branch and the back of the valve is prevented by a sliding piece k against
which the back of the valve b slides. The sliding piece is kept against the back
of the valve b by the pressure of the incoming motive fluid which acts on the
flange. Compressed air from the air pump can be admitted to the slide jacket m
in a similar manner to that described with reference to Figs 12 and 13. As the
products of combustion pass from the generator to the cylinder, they sometimes
carry with them grit or dirt, which, moving at a considerable velocity, would be
liable to act after the manner of a sand blast upon the plumbago. To obviate this
I provide a lip or lips or parts of metal arranged so as to protect the plumbago
directly exposed, but in such a position that it or they will pass over a part of the
port faces previously lubricated by the passage of the plumbago.
Such an arrangement is shewn in Fig 15 wherein metallic lips 66, 611 are
attached to the valve b.
It will be obvious that instead of forming the valve itself of plumbago I may
make the valve of metal and form the port faces of plumbago after the manner
shown in Fig 16-without departing from the essential feature of this portion of
my invention.
With reference to the said Fig 10, a is the cylinder, b the slide
valve, and c the plumbago facing upon which the said valve slides. The plumbago
used according to my invention is rendered cohesive in the manner usual when
making plumbago crucibles furnace linings and the like, but must not be gritty.
Another part of my invention has reference to an automatic arrangement by
which the governor of the engine is made to control the admission of air to the
generator in such a manner that when the engine exceeds its normal speed the
compressed air from the pump or pumps, or some of it, is caused to pass into a
receiver or accumulator instead of into the retort or generator.
Fig 17 illustrates in elevation, and Fig 18 in plan one form of apparatus I employe
for the purpose mentioned.
a is a chamber or casing containing a valve b. The said chamber is connected by
pipe c with the air compressing pump; by pipe d with an air receiver or accumu-
lator, and by pipe e with the retort or generator. The valve b is connected by its
spindle b¹ with a piston or plate 6 which is operated upon by a diaphragm f of
india rubber or other flexible material. The area of the diaphragın fexceeds that

page_text: of the valve b, and the arrangement is such that when compressed air is admitted
by the pipe g to one side of the diaphragm, it causes the valve to be opened
against the pressure upon it. The pipe g provided with a valve or cock / which
can be operated by the lever i, and governor rod j.
According to one position of the said valve or cock communication is established
between the pipe d and the diaphragm f; according to another position of the said
valve or cock communication with the pipe d is stopped and the air from the
diaphragm is free to escape into the atmosphere. When therefore the speed of the
engine increases, the governor causes the air to escape from the diaphragm, and
the valve b to be closed, whereupon the compressed air from the pump, instead of
being delivered to the generator, is transmitted to the receiver or accumulator.
But when the speed of the engine decreases the governor causes communication to
be established by the cock or valve with the diaphragm, whereupon the valve b is
opened and compressed air from the pump and from the accumulator is delivered
to the generator by the pipe e.
In lieu of the above described arrangement I may employ an apparatus such as
shewn in Figs 19 and 20. In this case the valve b is opened by the pressure of
compressed air from the pump and from the accumulator, and is closed in
opposition to the said pressure by the action of the diaphragm, as will be easily
understood.
In Fig 17 the arrows denote the direction taken by the compressed air when the
valve b is open.
In Fig 19 the arrows shew the direction taken by the compressed air when the
valve b is closed.
Fig 20 shews the position occupied by the diaphragm when air is being allowed
to escape for the purpose of enabling the valve (Fig 19) to open.
Another part of my invention has for object to enable the governor of the engine
to alter the period of "cut-off" to the working cylinder.
Fig 21 illustrates an arrangement for this purpose. a is a reciprocating or
rocking plate having in it a groove or cam path b. The necessary reciprocating
movement is produced by any convenient motion. When in one direction the
cam path or groove causes the valve for admitting motive fluid to the cylinder, to
be opened, and when the cam path or groove is in the other direction the valve is
closed. The period of closing is carlier or later according to the position of the
movable portion c of the cam path, which movable portion is controlled by the
governor of the engine, substantially in the manner shewn by means of a wedge d
and roller e which work in a quadrant f, the position of the said quadrant being
variable according to the movement of the governor rod as will be easily
understood. This arrangement is shewn applied to an ordinary drop valve of a
caloric engine.
.
Figs 22, 23 and 24 shew the general arrangement of a caloric engine according to
my invention, Fig 22, being a side elevation, Fig 23 an end elevation, and Fig 24
a plan.
a is the working cylinder provided with a plumbago slide valve arrangement
such as shewn in Fig 15. b is a pump for compressing air, the said pump having
an inlet valve arrangement such as described with reference to Figs 7 and 8. dis
the retort or generator connected to the valve chest e of the cylinder by a branch f
and provided with an outlet g through which the products of combustion can
pass by h¹ for the purpose of heating the cylinder whilst the fire is burning as
described with reference to Fig 4. j is a pipe for conveying the compressed air
from the pump to the valve chest e for subsequent delivery to the retort or
generator.
Having described the nature of the said invention and the manner of carrying
it into practical effect I hereby declare that what I consider to be novel and
original and therefore claim as secured to me under the Letters Patent first
hereinbefore in part recited is
In caloric engines.

page_text: 1 Utilizing the products of combustion evolved during the burning up of the
fire to heat the cylinder of the engine before admitting to the said cylinder motive
fluid from the generator substantially as described, so as to facilitate the starting
and working of the engine by preventing rapid condensation of the motive fluid
that first enters the cylinder to operate the engine as above set forth.
2. Causing the products of combustion to pass into a chamber in connection
with the cylinder of the engine for the purpose of heating the said cylinder whilst
the fire is burning up as respectively described with reference to and illustrated in
Figs 1 and 2 and in Figs 3 and 4 of the drawings.
3. The method substantially as described with reference to Figs 5 and 6 of the
drawings of utilizing heat radiated from the retort or generator to raise the
temperature of compressed air on its way from the pump to the interior of the
retort or generator for the purpose specified.
4. Providing the air pump with a suction slide valve arranged and operating
substantially as described with reference to Figs 7 and 8 of the drawings whereby
noise common to ordinary air valves is prevented, and the use of a stuffing box for
the valve rod is rendered unnecessary.
5. The use for admitting and discharging air to and from the air pump cylinder
of a slide valve capable of (1) assuming a position that will allow of suction.
(2) of assuming a position in which the valve will close the air inlet and delivery,
and (3) of being automatically moved by the pressure within the pump to a
position suitable for the delivery of the compressed air, substantially as described
with reference to Figs 9, 10 and 11 of the drawings.
6. The use of a slide valve having its body or working face formed of plumbago,
substantially as hereinabove described.
7. The several constructions of plumbago valves with metallic protecting lips
hereinabove described with reference respectively to and shewn in Fig 12, Fig 13,
Fig 14 and Fig 15.
8. Forming the working surface upon which a slide valve works of plumbago in
the manner and for the purpose specified with reference to Fig 16 of the
drawings.
9. The arrangement substantially as described with reference to Figs 17 and 18
of the drawings for automatically controlling the supply of compressed air to the
generator, so that when the engine exceeds its normal speed the compressed air is
caused to pass to a receiver or accumulator as above set forth
10. The arrangement substantially as described with reference to Figs 19
and 20 of the drawings for automatically controlling the supply of compressed air
to the generator, so that when the engine exceeds its normal speed the compressed
air is caused to pass to a receiver or accumulator as above set forth.
11. The method of varying the period of cut off of motive fluid to the cylinder
substantially as described with reference to Fig 21.
In Witness whereof I the said Charles Ingrey have hereunto set my hand
and seal this sixth day of December in the year of Our Lord one thousand eight
hundred and eighty three
CHARLES INGREY. (L.S.)