IMPROVE- MENTS IN HOT AIR ENGINES
Year: 1881

page_text: LETTERS PATENT to William Henry Bailey, of the Albion Works, Oldfield
Road, Salford, in the County of Lancaster, for an Invention of "IMPROVE-
MENTS IN HOT AIR ENGINES." Partly a communication from abroad by Messrs.
Zipf and Langsdorff, of Oberrad, Frankfort a/m, and the Berlin Anhaltische
Maschinenbau Action Gesellschaft, of Berlin, both in the German Empire.
PROVISIONAL SPECIFICATION left by the said William Henry Bailey at
"
the Office of the Commissioners of Patents on the 26th. March 1881.
WILLIAM HENRY BAILEY, of the Albion Works, Oldfield Road, Salford, in the
County of Lancaster. "IMPROVEMENTS IN HOT AIR ENGINES.' [Partly a com-
munication from abroad by Messrs. Zipf and Langsdorff, of Oberrad, Frankfort
a/m, and the Berlin Anhaltische Maschinenbau Actien Gesellschaft, of Berlin, both
in the German Empire.]
This Invention relates to that description of hot air engines in which a closed
chamber heated at one end by a fire contains a displacing plunger, by the motion
of which the air contained in the chamber is alternately sent from the hot to the
cold end, and from the cold to the hot end, so that by its resulting alternate
contraction and expansion it is made to work a piston in a cylinder. In engines
of this kind of present construction the cylinder communicates with either the hot
end or the cold end alone, whereby in the one case a loss of effect is experienced
by the heating of the air as it returns from the cylinder to the heating chamber,
while in the other case a similar loss is experienced through the cooling of the air
as it passes into the cylinder. According to one of the present improvements there
are provided in the heating chamber two passages, one communicating with the
hot end and the other with the cold end of the chamber, which passages lead to
ports in a surface against which works a surface on the side of the cylinder,
which is an oscillating one. This surface has a port from which a passage leads to
the closed end of the cylinder, and by the oscillation of the latter the said port and
passage are made to communicate alternately with the two passages in the heating
chamber, so that as the piston performs its outstroke, due to the expansion of the

page_text: air in the hot end of the chamber, the cylinder communicates with such hot end,
while when the piston is performing its instroke, due to the contraction of the air
in the cool end of the chamber, the cylinder communicates with such cool end.
By this means the above described losses of effect are avoided. Motion is imparted
to the displacing plunger in this arrangement by means of a crank rotated by the
piston of the cylinder working with its pin in the slot of a lever fixed on a transverse
rocking shaft having at the middle of its length an arm to which the rod of the
displacing plunger is connected, so that as the said crank pin revolves the requisite
up and down motion is imparted to the plunger by the rocking lever.
According to another arrangement, applicable either to the above construction
of engine or to that in which the cylinder is fixed and communicates only with
the one end of the heating chamber, the engine shaft rotated by the piston rod of
the cylinder has an eccentric whose strap is connected to a rocking arm or radius
rod having two forks in which are pivotted two looped .links extending upward
and connected at their upper end to a third central link whose upper end works up
and down through a guide, and whose lower end is connected by adjusting screw
nuts to the displacer rod. The engine shaft passes through the said looped links,
and the central link is cranked to pass round the shaft.
According to another improvement, applicable to the arrangement where the
cylinder is inverted and communicates with the cool end of the heating chamber,
an aperture is formed in the cylinder cover in which is a flap valve opening
inwards, and above this is an oil cup with capillary wick by which a constant
supply of oil is fed on to the said valve. As the piston performs its outstroke due
to the expanded air entering it, the said flap valve is kept closed by the air
pressure from within, but as the piston performs its instroke, due to the partial
vacuum produced by the contraction of the air, the flap valve opens and allows
the oil deposited thereon to pass in a divided form on to the piston, which is thus
continually lubricated, so that by this arrangement I am enabled to cause a metallic
piston to work against the metallic surface of the cylinder, which arrangement
could not before be applied to hot air engines of this description. By the opening
of the valve also the outer air can pass into the cylinder to make good any loss of
air that may take place through leakage while the air is expanding in the
cylinder.
According to another improvement applicable to either af the above described or
any other arrangement of caloric engines, the fire box enclosing the heated end of
the heating chamber is surrounded first by a jacket of suitable non-conducting
material such as slag-wool or asbestos, and surrounding this, with a small space
intervening, is the outer casing of the engine. Between the upper end of this
casing, which contains cold water surrounding the cool end of the chamber and
the lower end, openings are formed through which the air supply to the fire enters,
and whence it flows down through the annular space between the fire box and the
casing in order to pass into the former through the grate at bottom. By this
arrangement the air supply to the fire box is heated to a certain extent before
entering, resulting in a saving of fuel, while at the same time the outer casing of
the engine is kept cool.
According to another improvement applicable to either of the above described
or any other arrangement of caloric engine, the displacer rod is prolonged
sufficiently to enable a spring to be inserted between a plate fixed to the end of
the rod and a fixed support on the engine frame, the strength of the spring being
made such as to partly balance the weight of the displacer, and thus relieve
in proportion the mechanism working the displacer of its weight during the
up-stroke.
According to another improvement applicable to either of the above described or
any other arrangement of caloric engine, the cooling and heating surfaces for the
air are so arranged that the heating and cooling of the air is effected outside of the
working cylinder, such surfaces being to a certain extent made to act as a regenerator,
thus saving a proportional amount of heat that is otherwise wasted, and also

page_text: effecting economy in the water employed for keeping the cylinder cool. For this
purpose the water jacket surrounding the cooled part of the working cylinder has
narrow passages formed both in its inner and its outer walls, and in the walls of
this part of the cylinder are formed a number of holes communicating with the
inner passages. Similar narrow passages are also formed in the walls of the heated
part of the working cylinder which communicate at one end with the first named
passages, and at the other end with a perforated double bottom to the cylinder.
Thus the air is caused by the one motion of the displacer to pass from the cooled
part of the cylinder through the said openings and external narrow passages to
the heated end of the cylinder, whereby it is made to take up considerable heat
from the walls of such passages so as to become highly beated before entering the
hot end of the cylinder through the perforated double bottom. The displacer being
made to work loosely in its cylinder, the heated air in entering at its rear or lower
end can pass between it and the cylinder to the front or upper end so as to act
upon the working piston. On the return stroke of the displacer the heated air
passes in the reverse direction through the said passages, thereby giving up the
greater portion of its heat to the walls thereof, and entering the cooled part of the
cylinder through the side holes in the requisite cooled condition.
According to another improvement applicable in all cases where the displacer
and working piston are in line with each other, respectively in the heated and
cooled part of the cylinder, the movements of the displacer are made to take place
periodically or with a sudden action, while those of the working piston take
place continuously in the usual manner by the following arrangement :-The
working piston has a double piston rod connected to a crank on the engine shaft,
while the plunger has a single central piston rod passing through a central tubular
passage formed through the piston, such rod being connected to one arm of a bell
crank lever pivotted to the framing, the other arm of which is connected by a rod
either to a part of the crank of the engine shaft or to the end of the piston rod next
thereto. The piston rod of the displacer works with a packing in the tubular
passage of the piston, so as to prevent the air from passing through such passage
to and from the space between the piston and plunger.
According to another improvement applicable to either of the above described or
any other arrangement of caloric engine, the heating of the hot end of the cylinder
is effected by a furnace with continuous feed and without a fire grate arranged as
follows-The hot end of the cylinder is enclosed in flues so formed by partitions
in the brickwork as to cause the flames and hot gases to play round the cylinder
on their way to the smoke stack with which the communicate at one end, while
at the other end they communicate with a passage leading down to the bottom of
a vertical brickwork shaft or chamber of some height. This chamber has either at
the top or near the upper end of one of its sides a charging door by which fuel is
introduced so as to fill the shaft more or less. At the bottom the shaft has a
lateral opening closed by a door with regulated openings through which the outer
air can enter. A fire being kindled at the bottom of the shaft, combustion is there
maintained by the air passing in through the said side passage, while as the fuel
is consumed at the bottom of the shaft the column in the latter descends and is
replenished from time to time through the charging door at top.
According to another improvement applicable to either of the above described
or any other arrangement of caloric engine, I provide outside the smoke stack of
the furnace a pocket forming part of such smoke stack in which is placed a
pyrometer of any suitable known construction which serves to indicate the tempe-
rature of the gases passing off from the furnace, and thus enables the engine tender
to regulate the draught of the furnace accordingly by closing the damper in the
smoke stack or chimney more or less.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Henry Bailey in the Great Seal Patent Office on the
23rd September 1881.
-
WILLIAM HENRY BAILEY, of the Albion Works, Oldfield. Road, Salford, in the
County of Lancaster. "IMPROVEMENTS IN HOT AIR ENGINES." Partly a com-
munication from abroad by Messrs. Zipf and Langodorff, of Oberrad, Frankfort
a/m, and the Berlin Anhaltische Maschinenbau Actien Gesellschaft, of Berlin, both
in the German Empire.
My Invention relates to that description of hot air engine in which a closed
chamber heated at one end by a fire, contains a displacing plunger by the motion
of which the air contained in the chamber is alternately sent from the hot to the
cold end, and from the cold to the hot end, so that by its resulting alternate
contraction and expansion it is made to work a piston in a cylinder. In engines
of this kind the working of the displacer is according to my Invention effected in
the manner shewn in Fig. 1, which is a front elevation partly in section, and in
Fig. 2, which is a part side view of a hot air engine having its working cylinder A
inverted and communicating with the upper or cool end of the chamber. The
piston rod of this cylinder is connected by side rods to the crank B on the shaft C.
On this shaft I fix an eccentric D, which is connected to a rocking arm or radius
rod F, and to the lower ends of two looped links E, E. The upper ends of these
links (through the loops of which the shaft C passes) are jointed to a link G which
is curved to pass clear of the shaft. The link G has at its upper end a rod H
working in a guide, and at its lower end it is connected by an adjusting screw and
nuts to the rod K¹ of the displacer K. When the cylinder A is inverted, as shewn
in Fig. 1, I provide means of lubrication for its piston, as I will describe referring
to Fig. 3, which is a section to an enlarged scale of the upper end of the cylinder A.
Through the cylinder cover I form au aperture provided with a flap valve L opening
inwards, and above this I fix an oil cup M with a capillary wick by which a
constant supply of oil is fed on to L. As the piston performs its outstroke due to
the expanding air entering the cylinder the flap valve L is kept closed by the air
pressure within, but as the piston performs its instroke due to the partial vacuum
produced from the contraction of the air the valve L opens and allows oil to pass
in a divided form on to the piston which is thus continually lubricated, so that by
this arrangement I am enabled to use a metallic piston working against the metallic
surface of the cylinder, which arrangement could not before be conveniently
adopted in hot air engines of this description. By the opening of the valve L
air can also pass into the cylinder to make good any loss of air that may take
place through leakage while the air is expanding.
According to another improvement applicable to a caloric engine arranged as
shewn in Fig. 1, or to any other arrangement of caloric engine, the fire box N
enclosing the hot end of the heating chamber is surrounded first by a jacket O of
suitable non conducting material such as slag-wool or asbestos, and surrounding
this, with a small space intervening, is the outer casing P of the engine. Between
the upper end of this casing which contains cold water surrounding the cool end
of the chamber, and the lower end, openings are formed through which the air
supply to the fire enters, and whence it flows down through the annular space
between the fire box and the casing in order to pass into the fire through the grate
at the bottom, as indicated by the arrows in Fig. 1. By this arrangement the air
supply to the fire is heated to a certain extent before entering it, resulting in a
saving of fuel, while at the same time the outer casing of the engine is kept cool.
According to another improvement the displacer rod H is prolonged, as shewn in
Fig. 1, sufficiently to enable a spring S to be inserted between a collar fixed on the
end of the rod and a fixed support T on the engine frame, the strength of the spring
being made such as to partly balance the weight of the displacer, and thus

page_text: proportionately relieve the mechanism which works the displacer during the
upstroke.
According to another improvement applicable generally to hot air engines of the
kind referred to, the cooling and heating surfaces for the air are so arranged that
the cooling and heating are effected outside of the working cylinder, these surfaces
being to a certain extent made to act as a regenerator, thus saving a certain
amount of heat that would otherwise be wasted, and also effecting economy in
the supply of water for keeping the cylinder cool. For this purpose the water
jacket surrounding the cooled part of the cylinder is arranged as shewn in Fig. 4,
which is a longitudinal section of a horizontal hot air engine shewn at Fig. 5 in
plan, partly sectional. The water casing U has narrow passages formed both in its
inner and its outer walls, and in the wall of this part of the cylinder are formed a
number of holes V communicating with the inner passages. Similar narrow
passages are also formed in the walls of the heated part of the cylinder which
communicate at the one end with the passages of U and at the other end with a
perforated double bottom W to the cylinder. Thus the air is caused by the out
stroke of the displacer to pass from the cooled part of the cylinder through the
holes V and internal passages in U to the heated end of the cylinder, whereby it is
made to take up heat from the walls of the passages before entering the hot end
of the cylinder through the bottom W. On the return stroke of the displacer the
heated air passes in the reverse direction through the narrow passages, giving up
the greater portion of its heat to their walls and entering the cooled part of the
cylinder through the side holes in the requisite cooled condition.
According to another improvement applicable in all cases where the displacer
and working piston are in line with each other, the movements of the displacer are
made to take place periodically or with a sudden action, while those of the working
piston take place continuously in the usual manner by the arrangement shewn in
Figs. 4 and 5. The working piston A' has a double piston and connecting rod A
connected to the crank B on the engine shaft C, while the displacer K has a single
central piston rod K¹ passing through the piston and connected to one arm X of a
bell crank lever pivotted to the framing, the other arm Y of which is connected to
a part of the crank B. The piston rod K¹ of the displacer works through a tubular
passage of the piston A¹ through packing to prevent passage of air.
Fig. 6 is a
vertical section, and Fig. 7 is a side view, partly in section of a vertical hot air
engine in which the central rod K¹ of the displacer K is worked from the one
end Xof a bell crank lever, the other end Y of which is linked to a pin Y¹ on the
connecting rod which connects the working piston A¹ to the crank B on the engine
shaft C. The engine shewn in Figs. 6 and 7 is arranged for gas to be employed in
heating the lower end of its chamber. It might however be heated by fire as
the engine shown in Fig. 1. Also the modes shewn in Figs. 4 and 5, and in
Figs. 6 and 7 for working the displacer from the crank or connecting rod of the
working piston are obviously applicable whether the cylinders be arranged in line
vertically or horizontally.
According to another improvement applicable to either of the above described or
any other arrangement of caloric engine, the heating of the hot end of the cylinder
is effected by a furnace with continuous feed and without a firegrate, arranged as
shewn in Figs. 4 and 5. The hot end of the cylinder is enclosed in flues so formed
by partitions in the brickwork as to cause the flames and hot gases to play round
the cylinder on their way to the smoke stack Z with which they communicate at
one end, while at the other end they communicate with a passage leading down to
the bottom of a vertical brickwork shaft or chamber Z' of some height. This
chamber has either at the top or near the upper end of one of its sides a charging
door Zs by which fuel is introduced so as to fill the shaft more or less.
bottom the shaft has a lateral opening Z closed by a door with regulated openings
through which the outer air can enter. A fire being kindled at the bottom of
the shaft, combustion is there maintained by the air passing in through the said
side passage, while as the fuel is consumed at the bottom of the shaft the column
At the

page_text: in the latter descends and is replenished from time to time through the charging
door Zat top. Fig. 8 is an external elevation, and Fig. 9 is a plan of the engine
and furnace shewn in section at Fig. 4. Doors are provided for access to the
furnace and flue, and a thermometer A is applied at the exposed end of the
cylinder A to shew the temperature within and guide the attendant in managing
the fire. The heat may to a certain extent be regulated by a throttle valve damper
in the chimney Z worked by the expansion and contraction of a metallic chain or
strap Z³, the movements of which are magnified by a system of levers Zo. Instead
of the exterior chain or strap Z a bar Z' may be arranged, as shewn in Fig. 10,
within the brickwork of the furnace, and to this may be attached a dial Z³ to
indicate the temperature.
According to another improvement applicable to either of the above described
or any other arrangement of caloric engine, I provide outside the smoke stack of
the furnace a pocket forming part of such smoke stack in which is placed a pyro-
meter of any suitable known construction which serves to indicate the temperature
of the gases passing off from the furnace, and thus enables the engine tender to
regulate the draught of the furnace accordingly by closing the damper in the smoke
stack or chimney more or less.
Figs. 11 and 12 are respectively side and front views shewing a pyrometer Z³
thus arranged, the chimney Z being provided with a throttle valve damper; Figs. 13
and 14 shew respectively in section and in front view a modified arrangement, in
which the chimney Z is provided with a flap valve damper. The pocket in which
the pyrometer is inserted has a lateral aperture Z¹º for circulation of air.
Having thus described the nature of the said Invention and in what manner
the same is to be performed, I claim in respect of hot air engines in which air
transferred by a displacer is alternately heated and cooled within a closed
chamber,-
First. The combination of the eccentric D, radius F, and looped links E with the
displacer rod I, its guide H, and connecting link G for the purpose of working the
displacer from the engine shaft, substantially as described with reference to
Figs. 1 and 2.
Second. The method of lubricating the piston herein described with reference to
Fig. 3.
Third. The construction of fire box N with its casings O and P and air passages,
substantially as described with reference to Fig. 1.
Fourth. The use of a spring S for balancing the weight of the displacer as.
described with reference to Fig. 1.
Fifth. The construction of the water casing U and walls of the air chamber with
thin channels and perforations V and W for passage of the air, substantially as and
for the purposes set forth with reference to Fig. 4.
Sixth. Working the displacer from one arm of a bell crank lever, the other arm
of which is linked to the engine crank, as described with reference to Figs. 4 and 5
or to the connecting rod of the main piston, as shewn in Figs. 6 and 7.
Seventh. The construction and arrangement of furnace and flues, substantially as
described with reference to Figs. 4, 5, 8, 9, and 10.
.
Eighth. The use of a pyrometer in a pocket of the chimney, as and for the
purposes set forth with reference to Figs. 11, 12, 13, and 14.
In witness whereof, I, the said William Henry Bailey, have hereunto set
my hand and seal, this Twenty second day of September, in the year of our
"