Year: 1887

page_text: I LÉON BÉNIER, of 18 Rue des Pyramides, Paris, in the republic of France, 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 -
This invention relates to further improvements in the hot-air engine for which
Letters Patent were granted to me dated the 8th December 1884 No. 16131 the
present improvements relating, firstly, to the regulation of the speed of the engine
and, secondly, to the introduction of the coke into the furnace.
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawings in which figure 1 is a front
elevation and figure 2 a sectional plan of a hot-air engine with my present improve-
ments applied thereto; figure 3, is a transverse vertical section taken through the
axis of the cylinder of the engine and figure 4 is a horizontal section of the said
cylinder taken through the slide valve and exhaust valve. Similar letters in all the
figures represent similar parts.
According to the present improvements I fix the motor cylinder, constructed in two
parts a,
and b, on the end of the frame of the engine the motor-piston is connected to
the shaft by means of two connecting rods and an oscillating beam mounted on the end
of a column bolted on the top of the frame; the pump c, is placed inside the frame,
the cylinder b, forming the bottom of the pump; the pump-piston is operated by
means of two connecting rods and a beam. By reason of the relative positions of the
pump-piston and the motor-piston the pump cylinder is prevented from becoming oval.
The slide valve t, regulates the introduction of cold air into the pump during the
suction (the crank describing the arc C, D, A, figure 1) and the flowing back of the
same into the motor-cylinder; but communication exists between the pump and the
cylinder only when the crank is at B, figure 1, the motor piston being at the end of
its downward stroke and the exhaust valve closed; the pump then compresses during
the movement of the crank from A to B; at B, the air compressed in the pump enters
the cylinder; at C, all the air contained in the pump will have been forced back into

page_text: the motor-cylinder and the slide-valve t, closes communication between the motor-
cylinder and the pump. As the crank moves, from the position C, the hot gases
introduced into the cylinder continue to force the piston upwards by their expansion.
The crank having arrived at D, the exhaust valve is open and the hot gases escape during
the descent of the piston. These hot gases do not repass through the furnace in order
to reach the valve, the pipe conducting them thereto being situated in the cylinder a
short distance above the furnace. At the opening of this pipe is placed a small grate g¹ ;
the pipe for admitting cold air and the exhaust pipe are therefore separate and
distinct. The exhaust valve is operated by means of a cam mounted on the shaft the
said cam acting upon one end of a lever, the other end of which raises the spindle of the
valve. The slide valve t, is actuated by means of a cam mounted on the motor-shaft,
and acting on a lever connected to the slide by a connecting rod.
I will now describe the means I employ for regulating the speed of the engine.
The power produced by the motor is regulated at each stroke of the piston by
varying the pressure of the gases which fill the cylinder. As the quantity of air
which is introduced into the cylinder at each stroke is constant this pressure can only
be varied by giving to the hot gases a higher or lower temperature, and this result is
obtained by the following means:
The cold air introduced into the cylinder by the slide valve t, enters the same
through the two passages m and n; the passage m, leads a portion of the cold air
around the piston, whilst the other passage n, leads the other portion under the grate.
A throttle-valve, is placed over the passage n, and is actuated by the governor a¹ ;
when this valve is open the maximum quantity of cold air passes through the furnace
and the temperature of the gases will fill the cylinder and consequently the pressure
are also at a maximum. In proportion as the throttle valve is closed by the governor
the quantity of cold air which passes through the furnace is diminished and the
quantity of air which passes round the piston is correspondingly increased. The power
produced is thus varied at each stroke according to the power to be transmitted.
A second throttle valve 6, mounted on the passage m, is only made use of at the
starting of the engine during which it is kept closed; as soon as the engine is started
this valve is closed and is not again moved.
The coke is fed into the furnace by means of a slide valve d, which introduces it one
piece at a time; the slide valve d, works on the box g, bolted on the cylinder b, and
has a to-and-fro movement communicated to it from the shaft y, by means of two
connecting rods and a beam; the shaft y, receives its motion from the motor-shaft
through a driving band and four gear wheels so as to give the shaft y, a speed of about
ten revolutions per minute. The slide valve d, has a recess d¹, and when the slide is at
one end of its stroke this recess is uncovered and a piece of coke is introduced therein
by hand; the slide in coming back to the other end of its stroke draws along the piece
of coke the recess through which the piece of coke was introduced is first covered
over by the cover of the slide, then the recess comes into communication with the
passage f, made in the interior of the box g; the piece of coke falls into this passage
and thence onto the furnace. A small glass sight hole h, placed over the cover of the
slide allows of the furnace being seen when the recess d', is opposite the passage f.
Instead of placing the pieces of coke in the slide by hand I sometimes effect this
operation by means of an automatic distributor placed above the slide and constructed
of a conical box r, bolted on the cylinder a; some small lumps of coke are placed in
this box buckets s, are mounted on the outer circumference of a plate mounted on
the shaft v. This plate in revolving causes the buckets to pass upwards through the
coke a piece of coke is taken up by each bucket and then falls onto the plate j,
where it remains until it falls into the recess of the slide. The box r, is slotted to
allow of the passage of the plate carrying the buckets. In order to prevent the coke
contained in this box from falling through the hole through which the buckets enter,
the latter are arranged to enter the box through a passage a, cast with the box r,
and having its iuner section slightly larger than that of the buckets so that they can
pass easily. The length of this passage is such that when one bucket leaves it the
next one enters it; the coke therefore can now fall through the passage. Motion is

page_text: communicated from the shaft y, to the shaft v, by means of a pitch-chain. As there
are four buckets the shaft c, revolves once only for each four revolutions of the shaft y.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. In a hot-air motor having its furnace contained in the interior of the cylinder the
herein described arrangement for regulating the speed, consisting in the employment
of a throttle-valve or its equivalent operated by the governor and causing the re-
spective quantities of air which enter the cylinder through the furnace and around
the piston to be varied.
2. In a hot-air motor having its furnace placed in the interior of the cylinder the
herein described arrangement for introducing the coke consisting in the employment
of a slide which introduces the coke piece by piece.
3. The arrangement of automatic distributor whereby the coke is brought into the
slide piece by piece.