IMPROVEMENTS IN HOT AIR ENGINES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Henry Simon at the Office of the
Commissioners of Patents on the 27th September 1880. A communication
from abroad by Carl Amthauer, of Wertheim, Baden, in the German Empire.
HENRY SIMON, of No. 7, St. Peter's Square, Manchester, in the County of
Lancaster. "IMPROVEMENTS IN HOT AIR ENGINES." [A. communication from
abroad by Carl Amthauer, of Wertheim, Baden, in the Gerinan 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 bot
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 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.

page_text: 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 capilliary 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 of 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.