Improvements in Hot Air-engines.
Year: 1889

page_text: Date of Application, 28th May, 1889-Accepted, 20th July, 1889
COMPLETE SPECIFICATION.
[Communicated from abroad by JAMES ATKINS WOODBURY, of Herrick Street,
Winchester, in the County of Middlesex, JOSHUA MERRILL, of No. 36, Chester
Park, Boston, in the County of Suffolk, GEORGE PATTERN, of Emerson Street,
Boston, in the County of Suffolk, and EDWARD FRANKLIN WOODBURY, of No. 192,
Dartmouth Street, Boston, in the County of Suffolk, all in the State of
Massachusetts, United States of America, Mechanical Engineers.]
Improvements in Hot Air-engines.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co. Patent Agents,
Southampton Buildings in the County of Middlesex, 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 that class of air-engines in which the energy exerted is due
to the alternate raising and lowering of the temperature of the same mass of air, and
it has for its object a more perfected air-engine of this class.
In the accompanying drawings
Figure 1 represents the air-engine in front elevation.
Figure 2 is a rear elevation of the same.
Figure 3 is a plan, and
Figure 4 is a central vertical sectional view of the same on line 10, 10 of Figure 1.
The essential features of my improved air-engine consists of a heater, a regenerator,
and a cooler, which three in combination are termed a reverser, and in conjunction
The drawings
with a working cylinder, constitute a single acting air engine.
represent a double acting air-engine, with two reversers and two working cylinders.
The bed plate 11 made in halves for convenience is designed to receive all the
parts of the engine which are super-imposed thereon.
The reverser side 8 is constructed as follows :-
The reverser furnace 12 which is lined with fire brick to lessen radiation is
provided with the flange 13 by means of which the furnace is bolted to the bed plate,
door 14, ash door 15, grate supporter 16, grate 17, nozzle 18 and flange 19, by
Underneath the
means of which the regenerator cylinder 20 is bolted to the furnace.
grate is the ash pit 21.
The regenerator cylinder 20 is provided with a flange 22, by which the cylinder is
bolted to the reverser furnace and to which the reverser heater 23 is bolted; pipe 24
and flange 25 to which is bolted the cooler 26.
The cooler 26, is provided with the flange 27 by which it is bolted to the
regenerator cylinder, flange 28 to which is bolted the cooler cover 29, air directing
pipe 30 and annular tube and water space. 31, through which extend the copper
cooling tubes 32, which are securely expanded into the tube holes in the flanges 27,
and 28. The annular space is provided with the water inlet pipe 33 and the water
outlet pipe 34. To the displacer cylinder portion 35 of the cooler is fastened the
displacer cylinder 36. To the upper part of the displacer cylinder portion of the
cooler, a row of regenerator pins as 37, are fastened and to the lower portion of
the displacer cylinder, a row of regenerator pins as 38, are fastened. The space
between displacer cylinder portion and displacer cylinder and the regenerator cylinder
Within this space is placed
and reverser heater, is termed the regenerator space 39.
the regenerator 40 which is made preferably of yellow-high brass wire cloth size of
wire about number twenty five Stubbs wire gauge and about twelve mesh. This wire
is wound on and around the displacer cylinder portion 35 and displacer cylinder 36
between the rows of regenerator pins, as 37, and 38, until a continuous roll is
formed, of a thickness sufficient to fill or nearly fill the regenerator space, then the
end of the roll is fastened, so as to prevent its unwinding.

page_text: The reverser piston 41 is provided with the piston head 42; piston rod 43;
follower 44; and a style of packing commonly known as the two ring packing,
composed of the two packing rings 45 and 46 placed between the composition
seats 47 and 48 of the piston head and follower respectively. The rings are set out
radially by a series of leaf springs as 49, and setting out bolts, as 50, in the usual
manner. To the reverser piston head is bolted the reverser piston lower section 51,
which is provided with the air port 52.
The cooler cover 29, which is bolted to the cooler, is provided with the nozzle 53,
designed to receive the two leather cupped packings 54 and 55 for the reverser piston
rod, relief packing ring 56, and gland 57.
The reverser side 8 is a duplicate of the reverser side 8, and in a like manner is
provided with the reverser furnace 12¹ having flange 131; door 14'; ash door 15¹;
regenerator cylinder 20¹ having pipe 24' and flanges 22¹ and 251; cooler 26¹ having
flanges 27 and 28', water inlet pipe 33¹; and water outlet pipe 34'; and cooler
cover 291 having nozzle 53¹ and gland 571, through which extends the reverser piston
rod 43¹.
To the cooler covers 29 and 29¹ is bolted the reverser beam stand 58, in which is
mounted the trunnion 59. To the trunnion is fastened the reverser beam 60, provided
with the reverser beam pins 61 and 61'; and side lever 62 provided with pin 63.
To the reverser piston rod 43 is keyed the crosshead 64, which is provided with
the cross-head pin 65, the cross-head pin 65 and reverser beam pin 61 are connected
by means of the connecting link 66.
In a like manner to the reverser piston rod 431 is keyed the cross-head 64' which
is provided with the cross-head pin 65. The cross-head pin 65¹ and reverser beam
pin 611 are connected by means of the connecting link 66'.
The working cylinder furnace 67, which is lined with fire brick to lessen radiation,
is provided with the flange 68, by means of which the furnace is bolted to the bed
plate; nozzle 69; nozzle 70; and flange 71, by means of which, the working
cylinder 72 is bolted to the furnace.
The working cylinder 72 is provided with the flange 73, by which the cylinder is
bolted to the working cylinder furnace, and to which is bolted the working cylinder
heater 74; pipe 75; pipe 76; and flange 77, to which is bolted the working cylinder
head 78.
The working cylinder heater 74 is provided with the side air port 79.
The working cylinder piston 80 is provided with the piston head 81; piston rod 82;
follower 83; and a style of packing commonly known as the three ring packing,
composed of three packing rings 84, 85 and 86, placed between the piston head and
follower.
The rings are set out radially by a series of leaf springs, as 87 and setting out bolts,
as 88, in the usual manner. To the working cylinder piston head is bolted the
working cylinder piston lower section 89.
The working cylinder head 78 which is bolted to the working cylinder is provided
with the two leather cupped packings 90 and 91 for the working cylinder piston
rod; relief packing ring 92; and gland 93; and the two cross-head guides 94 and 95
which are securely bolted to the working cylinder head.
The working cylinder side 9¹ is a duplicate of the working cylinder side 9, and in
a like manner is provided with the working cylinder furnace 67' having flange 681;
nozzle 691; and nozzle 701; working cylinder 72¹ having flange 73; pipe 75¹
pipe 761; and flange 77¹; and working cylinder head 78', provided with cross-head
guides 94 and 951 through which cylinder head extends the working cylinder piston
rod 82¹.
To the working cylinders 72 and 721 is bolted the working cylinder beam stand 96,
in which is mounted the trunnion 97. To the trunnion is fastened the working
cylinder beam 98 provided with the horn 99 and the beam pins 100 and 100¹ and 101.
To the working cylinder piston rod 82 is keyed the cross-head 102 adapted to slide
on and to be guided by the cross-head guides 94 and 95, and provided with the cross-
head pin 103.

page_text: The cross-head pin 103 and the working cylinder beam pin 100 are connected by
means of the connecting link 104.
In a like manner to the working cylinder piston rod 821 is keyed the cross-head
1021 provided with the cross-head pin 103. The cross-head pin 103' and working
cylinder beam pin 100', are connected by means of the connecting link 104'.
The cross-head guides 94 and 95 are braced by means of the cross-head guide
braces 105 and 106 respectively.
In a like manner, the cross-head guides 94¹ and 95¹ are braced by means of the
cross-head guide-braces 105¹ and 106¹ respectively.
To the bed plate, the pillow blocks 107 and 108 are bolted. The pillow block 107
is braced by means of the reverser furnace brace 109. The pillow block 108 is braced
by means of the working cylinder brace 110, to which is bolted the centrifugal
governor 111 of a common style. Within the pillow blocks, the main shaft 112 is
journalled which is provided with reverser crank 113 having reverser crank pin 114;
air pump excentric 115, having excentric straps 116; fly wheel 117; governor
pulley 118; thrust collar 119; and working cylinder crank 120, having working
cylinder crank pin 121.
The air pump 122, bolted to bed plate, is of the single acting piston type and is
operated in the usual manner by means of air pump excentric 115. It is provided
with the air inlet pipe 123, and the air outlet pipe 124.
The reverser beam side lever pin 63 is connected with the reverser crank pin 114,
by means ef reverser connecting rod 125.
The pulley 126 of the governor is connected with governor pulley 118 by means
of belt 127.
The pin 101 of the horn 99, of the working cylinder beam is connected with
working cylinder crank pin 121 by means of working cylinder connecting
rod 128.
The reverser side 8 is connected with the bottom of working cylinder 72 by means
of pipe 24, pipe 7 and lower connecting pipe 129 and flanges.
In a like manner the reverser side 8 is connected with the bottom of working
cylinder 72 by means of pipe 24', pipe 751, and lower connecting pipe 129¹ and
flanges.
The top of working cylinder 72¹ is connected with reverser side 8 by means of
pipe 761, and upper connecting pipe 130 and flanges, which upper connecting pipe
extends through the cooler cover 29.
In a like manner the top of working cylinder 72 is connected with reverser side 8¹
by means of pipe 76 and upper connecting pipe 130 and flanges, which upper con-
necting pipe extends through the cooler cover 29'.
To the pipe 76 is connected the check valve 131, which is of a common style, and
is designed to operate in the usual manner.
In a like manner :-to the pipe 76' is connected the check valve 131'.
The check valves 131 and 131' are connected with the air pump by means of the
air pump
outlet pipe 124.
The safety valve 132, of a well known style, is connected with the air pump outlet
pipe 124.
The governor valve 133 is connected on one side, by means of piping 134, with
pipe 76 and on the other side by means of piping 134, with pipe 76¹. The governor
valve is of the reciprocating type and is provided with the stem 135 which is
connected with one end of the governor lever 136, a lever of the first class, pivoted
at 137. The other end of the governor lever is connected with the spindle 138 of the
governor.
The working cylinders 72 and 72¹ are provided with the blow off valves 139 and
139¹ respectively.
In the construction of the reverser side 8 suitable ports are made for the free
passage of the air displaced by the displacer piston, from the cool chamber 140 above
the displacer piston, into and through the cooling tubes, through the regenerator,
around the lower portion of displacer cylinder and into the hot chamber. 141 below

page_text: the displacer piston; also from the cool chamber 140, through pipes 180 and 76;
to the top portion of working cylinder 721, and into the space above the working
cylinder piston and from the hot chamber 141, through port 52, pipe 56, pipe 24,
pipe 129, and pipe 75 into the lower portion of working cylinder 72 through port 79
and into the space below the working cylinder piston 0. In a like manner, in
reverser side 31, suitable ports are made for the free passage of the air displaced
by the displacer piston from the cool chamber, to the hot chamber, and from the cool
chamber to the top portion of working cylinder 72, and into the space above the
working cylinder piston 80 and from the hot chamber to the lower portion of
working cylinder 721 and into the space below the working cylinder piston
of working cylinder 72'.
Description of the preliminary steps to be taken prior to the starting of the
engine.
It being determined to have the engine run over as indicated by arrow on fly wheel
the relative positions of the cranks 113 and 120 should be such as will give the
reverser piston of reverser side 8 a lead over the working cylinder piston of the
working cylinder side 9, of from one third to one half stroke, the lead represented in
Figure 4 is one half stroke, the direction of movement of the pistons being indicated
by arrows in Figure 4. The reverse pistons of reverser sides 8 and 81 being
connected by means of the reverser beam and connecting parts and the working
cylinder piston of working cylinder sides 9 and 91 being connected by means of
working cylinder beam and connecting parts, it is evident that the reverser piston
of reverser side 31 will have the same lead over the working cylinder piston of
working cylinder side 91 as the reverser piston of reverser side 8 has over working
cylinder piston of working cylinder side 9.
The water inlet pipe 33 of cooler 26 is connected with suitable water supply and a
circulation of water is maintained in the annular tube and water space 31, and out of
the cooler through water outlet pipe 34, from which the water is conveyed by means
of suitable piping, to any convenient place.
In a like manner, a circulation of water is maintained in cooler 26¹ through water
inlet pipe 33' and water outlet pipe 34¹.
A fire is then started in both of the reverse furnaces. In reverser side 8 the fire is
started upon the grate 17. within the reverser furnace 12, and the products of
combustion pass about and around the reverser heater 23 through nozzles 18 and 19
into the working cylinder furnace 67, then about and around the working cylinder
heater 74 and then escapes through the nozzle 70, into chimney through suitable
piping.
In a like manner, in reverser side 8', the products of combustion pass from reverser
furnace 12¹ to working cylinder furnace 67¹ through nozzles 18¹, and 69¹, and then
escapes through the nozzle 70'.
When sufficient heat has been imparted to the reverser and working cylinder
heaters, the engine may be set in operation, by giving the fly wheel about an one half
revolution in the direction of its running movement.
"
In the operation of the engine the alternate raising and lowering of the temperature
of the same mass of air is accomplished as follows:-In the upward stroke of the
reverser piston 41 the mass of air in the cool chamber 140 is forced. First: Through
the cooling tubes, in its downward passage through which, the temperature of the air
is not materially changed. Second: The air enters the regenerator 40, and in its
passage through the regenerator it absorbs heat which has been imparted to the
regenerator. Third: The air then passing over the heated surface of the reverser
heater, thereby becoming further heated, enters the hot chamber 141.
The temperature of the air in the cool chamber is about 120° F., and the temperature
of the air in the hot chamber is about 600° F.
In the downward stroke of the reverser piston 41 the mass of air in the hot
chamber 141 is forced: First: To the regenerator 40: Second: The air enters the
regenerator and in its passage through the same, it deposits thereon the greater
portion of its heat. Third Through the cooling tubes where its temperature is

page_text: reduced to about 120° F., and then into the cool chamber 140. Therefore at each
upward and downward stroke of the reverser piston of reverser side 8 the temperature
of the same mass of air is alternately raised and lowered ; and the reverser side 8¹
being a duplicate of reverser side 8, it is evident that the same alternate raising and
lowering of the temperature of the air would take place in reverser side 81 as in
reverser 8, but at opposite times, that is to say, both reverser pistons being operated
by the reverser beam, whenever one reverser piston is making its upward stroke, the
other reverser piston is making its downward stroke. It is therefore evident, that
when the air in one reverser side is being heated, the air in the other reverser side
is being cooled.
The alternate raising and lowering of the temperature of the reversed air, in both
reverser sides, generates a power in accordance with the well known laws of the
expansion of gases, which power is developed by the working cylinders as
follows-Referring to Figure 4 and presuming the movements of the reverser and
working cylinder pistons, to be in the direction as indicated by arrows.
The reverser piston of reverser side 8 is making its upward stroke and is heating
and expanding the displaced air, thereby producing a pressure which is exerted
against the bottom of working cylinder piston of working cylinder side 9, and
against the top of working cylinder piston of working cylinder side 9¹, between
which and the reverser side 8 are open ports, while at the same time, the reverser
piston of reverser side 8¹ is making its downward stroke and is cooling and con-
tracting the displaced air, thereby reducing the pressure against the bottom of
working cylinder piston of working cylinder side 91 and the top of working
cylinder piston of working cylinder side 9, between which and the reverser side 81
are open ports.
Thus each working cylinder piston is subjected to differential pressures which are
alternately reversed as the displaced air is alternately heated and cooled. Thus a
power is exerted to cause the working cylinder pistons to have reciprocating motion,
which is changed to a rotary motion by means of the working cylinder beam and
its connected parts to the inain shaft and fly wheel, from which the power may be
taken off by means of a belt. A portion of the power developed is absorbed in the
friction of the engine and a portion is used to operate the reverser pistons by
means of a reverser crank, reverser connecting rod side lever, trunnion, reverser beam
and connected parts.
The engine is designed to run on an initial pressure of air, of from four to five
atinospheres, and the duty of the air pump is to supply and maintain this initial
pressure of air in the engine which duty is accomplished as follows:-
After the starting of the engine at each revolution of the engine a certain quantity of
air is pumped by the air pump into the air outlet pipe 124, from which the engine
receives the compressed air which passes into reverser side 8 through check valve 131'
pipes 76 and 130, and into reversed side 81 through check valve 131 pipes 76,
and 130. In practice, a reservoir is usually placed, for convenience in circuit, with
the air outlet pipe 124. The safety valve 132 is placed on the air outlet pipe 124,
for the purpose of controlling the pressure of the air supplied to the engine. By
setting the safety valve at 45 pounds from zero, or four atmospheres, it is evident,
that any air above that pressure will be permitted to escape into the atmosphere
through the safety valve, and as the safety valve may be set at any number of
pounds desired, it is obvious, that any initial pressure may be maintained in the
engine. The air pump not only supplies the initial pressure but it supplies any
leakage of air that may leak out of the engine around the piston rods and flange
joints.
The duty of the governor and governor valve is to equalize the differential
pressure in the engine, and as the differential pressures are the power producing
factors of the engine, therefore, in regulating the difference of the differential
pressures, the power, and consequently the speed of the engine may be regulated.
This regulation of the engine is accomplished as follows.
The governor being of the ordinary centrifugal style and being connected with

page_text: - the
governor valve, of a reciprocating type, by means of the lever of the first class,
any increase of speed of the engine would raise the governor balls, thereby depressing
the spindle of the governor and raising the stem of the governor valve thereby
opening the governor valve, which controls the opening between the two reverser
sides of the engine, that is to say, between reverser sides 8 and 8', and as the size of
the opening between the two reverser sides of the engine is controlled by the action
of the governor, in opening and closing the governor valve, the difference of the
differential pressures is consequently controlled, and therefore the power and speed of
the engine is regulated.
:
It has been determined by us after many years of costly, scientific, and practical
experimenting, that the following special construction and arrangement is of vital
importance.
The cold chamber should be directly connected with the top of a working cylinder,
and the hot chamber should be directly connected with the bottom of a working
cylinder.
The regenerator should occupy the regenerator space between the regenerator
cylinder, reverser heater, and displacer cylinder and should extend from the cooler to
a point at or near the bottom of the reverser heater.
That the regenerator should be composed of wire cloth and located in the
regenerator space as stated.
That the cooler should have a cast annular tube and water space.
That the cooler should be provided with a cooler cover as represented and
described which should be provided with a connecting pipe to a working cylinder.
That the cooler should have a cast annular tube and water space through which
should pass the cooling tubes.
That the cooler should have cast thereon a displacer cylinder portion.
That the displacer cylinder should be securely fastened to the displacer cylinder
portion of the cooler.
That the regenerator should be composed of wire cloth and should be wound on to
the displacer cylinder portion and displacer cylinder.
That the regenerator composed of wire cloth and wound on to displacer cylinder
portion and displacer cylinder, should be held in position vertically between rows of
regenerator pins.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to me
by my foreign correspondents I declare that what I claim is :
First. An air engine in which the temperature of the same mass of air is alternately
raised and lowered, having a reverser provided with a hot and cold chamber, each of
which, being directly connected with a working cylinder, substantially as and for the
purpose set forth.
Second. In an air engine, in which the temperature of the same mass of air is
alternately raised and lowered, the reverser side, as 8, provided with the regenerator
space formed between the regenerator cylinder, reverser heater, and displacer
cylinder, within which is placed the regenerator, in combination with the tubular
cooler, having the cooling tubes, and provided with the cooler cover, substantially as
described.
Third. In an air engine in which the temperature of the same tnass of air is
alternately raised and lowered, having the reverser side, as 8, the combination with
the tubular cooler, having the cooling tubes, and provided with the cooler cover; the
regenerator composed of wire cloth and placed within an annularly constructed space
at or near the inner surface of the outer shell of the heater, substantially as and for
the purpose set forth.
Fourth. In an air engine, the combination with reverser heater, provided with an
annular regenerator space at or near the inner surface of its outer shell, the cooler,
provided with the annular tube and water space, having the cooling tubes, and
provided with the cooler cover, substantially as described.

page_text: Fifth. In an air engine, the combination of the reverser heater, a wire cloth
regenerator, the tubular cooler, and cooler cover provided with the connecting pipe
by means of which the cold chamber is directly connected with a working cylinder,
substantially as and for the purpose set forth.
Sixth. In an air engine, the combination with the reverser heater, the cooler
provided with the annular tube and water space; and cooler cover, and having the
cooling tubes and the cold chamber, within which the displacer piston reciprocates,
substantially as described.
Seventh. In an air engine, having a reverser side, as 8, the tubular cooler, having
the cooling tubes, and provided with the cooler cover, within which cooler the
displacer piston reciprocates, provided with the displacer cylinder portion cast on said
cooler, said portion being adapted to receive within it the displacer piston, sub-
stantially as described.
Eighth. In an air engine, having a reverser side, as 8, the tubular cooler, having
the cooling tubes, and provided with the cooler cover, within each cooler, the displacer
piston reciprocates, provided with the displacer cylinder portion, in combination with
displacer cylinder (adapted to receive within it the displacer piston) fastened to said
displacer cylinder portion, substantially as and for the purpose set forth.
Ninth. In an air engine having a reverser side, as 8, the combination with the
cooler having the cooling tubes and provided with the displacer cylinder and cooler
cover, the regenerator wound on said displacer cylinder, composed of wire cloth,
substantially as described.
Tenth. In an air engine having a reverser side, as 8¹, the cooler provided with
displacer cylinder which is provided with a series of regenerator pins, as 37 and 38,
in combination with the regenerator composed of wire cloth and wound on said
displacer cylinder and between said series of regenerator pins, substantially as
described.
Eleventh. An air engine in which the temperature of the same mass of air is
alternately raised and lowered, having the reversers, each of which is provided with
a hot and a cold chamber, when each of said chambers is directly connected with the
working cylinders, substantially as described.
Twelfth. In an air engine in which the temperature of the same mass of air is
alternately raised and lowered, the combination of two reversers and two double acting
working cylinders, with a regenerator composed of wire cloth, said cylinders being
directly connected by means of the connecting pipes, substantially as described.
Thirteenth. In an air-engine in which the temperature of the same mass of air is
alternately raised and lowered, having a reverser provided with a hot and cold
chamber, each of which is directly connected with a double acting working cylinder
in combination with a regenerator, substantially as described.
Fourteenth. In an air-engine, in which the temperature of the same mass of air
is alternately raised and lowered, having a reverser provided with a heater, regenerator
cylinder, a wire cloth regenerator and a tubular cooler, having the cooling tubes, and
provided with the cooler cover, so constructed and arranged as to provide for an
annular port having straight or nearly straight sides and extending from the cooler
to the bottom of the heater, so that the air may have a direct and a free passage to
and from the hot and cold chambers, substantially as described.
DILA DOIL 1
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.