IMPROVEMENTS IN ATMOSPHERIC ENGINES
Year: 1886

page_text: I, ALEXANDER HENRY REED, of Suffolk House, Laurence Pountney Hill, Cannon
Street, in the county of Middlesex, Engineer, do hereby declare the nature of said
invention for IMPROVEMENTS IN ATMOSPHERIC ENGINES 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 improvements in that class of atmospheric engines in
which the motive power is obtained by admitting heated air to a cylinder during
the entire or part of the stroke of the piston, so that a partial vacuum is formed on
one side of the piston by the rarified air and the excess of atmospheric pressure on
the other side of the piston affects its propulsion.
The invention consists essentially in the combination with a cylinder and with
the piston of an air admission port at one end of the cylinder, a slide for controlling
the same, a burner or other device for directing a flame to the air admission port,
proper exhaust ports, a valve governing the same, and means for imparting the
requisite motion to the valve and slide, and for controlling the supply of heat at
the admission port, all of which is more fully pointed out in the following
specification and claim, and illustrated in the accompanying drawing, in which
Fig. 1 is a sectional elevation of a prime mover constructed according to the
invention.
Fig. 2 is an inverted plan view of the slide and fittings for controlling the air
admission port.
Fig. 3 is an horizontal section in the plane X X fig. 1 of the beat supply
controlling apparatus.
Similar letters indicate corresponding parts.
In this drawing the letter A designates the cylinder of the engine, which is
provided with an air admission port a at one end, an exhaust passage b, leading
from the lower end of the cylinder, and an air exhaust passage c, which leads from
the upper end of the cylinder. B is the piston, one part d of which is fitted to the
cylinder, whilst the remaining part d' is of a smaller diameter and is in the form of
a hollow plunger to the bottom of which is attached one end of the connecting
[Price Ed.]

page_text: rod b¹.
A disk or cup be is attached to the bottom of the piston so as to leave an
air space beneath the piston to prevent undue heating thereof, but other well-
known means may be employed for this purpose. C is the crank shaft which can
carry a driving wheel and a fly wheel as usual and is supported in suitable
standards c¹, c³, secured to the cylinder.
The cylinder rests upon a casing D in which is located a burner E which is so
situated that the flame will be directed to the air admission port a of the cylinder.
The burner E is connected with a cock F and a supply of gas is led to the burner
through suitable tubing not shown in the drawing, which is connected with a
pipe f, which is in communication with the cock F, so that when the cock is turned
in the proper direction, the gas supply will be shut off. To open or close the air
admission port a, a slide G, figs. 1 and 2 is provided, which consists of a metallic
plate g, supported upon a sliding piece g', which can inove longitudinally in guide
ways g³, secured to the cylinder head.
In order to keep the plate g continually pressed against the cylinder a flat
spring g is interposed between the piece g¹, and the plate.
To open and close the exhausts b, c, in a manner hereinafter to be described, a
slide valve H, fig. 1 is employed, which is guided in a valve case formed in the
standard c, and is so constructed that when it is in the position shown in fig. 1,
the two exhaust passages b, c, are in communication, but when it is in its extreme
opposite position the exhaust port c, is open and the fluid above the piston can
make its exit through this port c. The proper reciprocating motion is imparted to
the slide valve H and slide G by means of a valve lever I, pivoted at i, to the
standard c, and to which the slide valve is connected by a link h which is pivoted
to the valve and to the valve lever. The lower end of the lever I projects through
a hole in the slide G but can be connected thereto in any other suitable manner.
The upper end of the valve rod I is provided with a roller stud i, which engages
with a groove, in a grooved cam I, which is mounted on the crank shaft Cand
rotates therewith. To regulate the supply of gas, an arm F¹ is attached to the plug
of the cock F, figs. 1 and 3, which arm has therein a curved slot which is engaged
by a pin G¹ projecting downwardly from the slide G, so that when the slide is
caused to reciprocate, the supply of gas will be alternately nearly shut off or 'turned
on full.
As shown in the drawing, fig. 1, the piston is on its upward stroke in the direction
of arrow 1 and has passed through about three quarters of its stroke and the crank
shaft C is turning in the direction of arrow 2. The slide valve H now covers the
exhaust port c, the slide G almost closes the air admission port a, whilst the gas
supply is nearly shut off, leaving only a sufficient supply to afford a very small
flame. As the piston now proceeds in the direction of arrow 1 in the completion
of its up stroke, the valve H is moved a very slight distance toward the cylinder
and the slide G is moved sufficiently to completely close the admission port, so that
the gases beneath the piston are allowed to expand freely and thus increase the
vacuum. The difference of pressure now existing on the opposite faces of the piston
causes the piston to descend, and during this downward stroke the positions of the
valve H, slide G and consequently that of cock F remain unchanged owing to the
path of the groove in the cam I', and the air below the piston is forced up passage b
through port c and in the space above the piston. Suppose the piston to be at the
end of its downward stroke, and begin a new cycle. As the piston starts upward,
the valve lever I is caused to turn about its fulcrum in the direction of arrow 3 and
valve H is moved in direction of arrow 4 so as to clear the exhaust port c, but to
obstruct exhaust passage b, so that the air which had been introduced above the
piston in the previous stroke, is expelled through port e into the open air.
By the same movement of the valve lever I the slide G is moved in the proper
direction to completely open the admission port a whilst at the same time the gas
supply cock E, is turned on full. The flaine now enters through port a into the
space below the piston and the exterior air drawn into the cylinder is heated
thereby very rapidly since the flame will be in thorough contact with the air,

page_text: sufficient oxygen being continually supplied by the influx of fresh air. As the
piston continues in its stroke the valves again return to the position shown in fig. 1,
when the gas supply and exhaust are cut off. This cut off can be fixed according
to the usual rules of practice at such a point which will be productive of the
highest economical effect.
In the drawing only one burner is shown but for larger sizes of engines several
burners could be used if necessary.
From the preceding. description it will be seen that the heated air does not in the
least act in driving the piston, but is only a medium necessary to produce a vacuum
on one side of the same, which results in a pressure tending in the opposite
direction due to the surrounding atmosphere. A water jacket as usually employed
with this class of engines, is superfluous with this improved construction as the
inaterial of the cylinder will never be subjected to an extremely high temperature
owing to the fact that the supply of heat is almost completely shut off when not
in immediate use.
It will be noticed that during the downward stroke of the piston the gases
contained in the lower part of the cylinder exhaust into the upper part of said
cylinder without meeting the resistance of the atmospheric pressure and con-
sequently the atmospheric pressure acting upon the piston froin above will drive
the same clear down to the bottom end of its stroke.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. The combination substantially as shown and described, with the cylinder and
the piston fitted therein of the air admission port a at one end of the cylinder, the
slide controlling the port a, the burner or other device for directing a flame to the
admission port, the exhaust ports b, c, the valve governing the same, and means
substantially as described for imparting the requisite motion to the valve and slide,
and means for controlling the supply of heat at the admission port.
2. In an atmospheric engine, the combination with the cylinder of a piston
having a head d closely fitted to the bore of the cylinder, and a plunger or rod
extending from the piston head, ports b, c leading from the cylinder and a valve H
controlling said ports substantially as and for the purpose specified.
3. The combination, with the cylinder and the piston, of the admission port a,
the slide G, grooved cam 1', valve lever I, engaging said cam and the slide
substantially as shewn.
4. The combination, with the cylinder and the piston of the admission port a,
the gas burner E, cock F, reciprocating slide g, and the connection of the slide with
the cock substantially as shewn and described.
CT
1000