IMPROVEMENTS IN CALORIC ENGINES
Year: 1884

page_text: I HENRY LONG of 12 Armoury Square, Stapleton Road in the City and
County of Bristol, Engineer, do hereby declare the nature of said invention for
"IMPROVEMENTS IN CALORIC ENGINES," to be as follows:-
This invention relates, firstly, to means employed for regulating the supply of air
to the retort or generator, and consists in the use of a receiver or reservoir
intervening between the said retort and the air pump. The receiver or reservoir
is placed in any convenient position and is charged from the pump through a
double-seated equilibrium valve conveniently situated on the cover of the pump.
It may be situated elsewhere, if desired. Thus a constant and regular supply of
air for actuating the piston of the working cylinder is provided, and spasmodic and
irregular working of the engine, due to the absence of such receivers in the engines
as hitherto constructed, obviated.
The double-seated equilibrium valve aforesaid constitutes a second improvement
effected under this invention. It is of annular form and presents a reduced
bearing surface for the pressure of the compressed air re-acting upon it from
the receiver or reservoir. Being provided with two orifices, a shortened vertical
travel or lift suffices for the outlet of the air. By the use of the valve so con-
structed the impact between it and the seats is lessened and noise consequently
Bubdued.
Governing the admission of the air from the receiver or reservoir to the retort or
generator is a valve similar in construction to the pump valve before described.
This valve is operated by the governor, the movable vertical spindle of which
takes, at its lower end, into a socket formed in the upper end of a spindle the
lower end of which is secured to the valve. To the socket is attached one end of a
lever carrying, at the other end, a counterweight the normal tendency of which is
to maintain the inside of the bottom of the socket against the lower end of the
governor spindle and thereby enable the governor to operate the valve. By means
of a regulating screw placed between the counter weight and the fulcrum of the
lever the valve may be operated to close, and thus to arrest the working of the
engine independently of the action of the governor. This cut off arrangement
constitutes a further improvement effected under the said invention.
A fourth improvement relates to a further means of controlling the engine
independently of the action of the Governor,

page_text: It consists in the employment of a pair of conical valves which are capable of
operation by hand. One of these valves controls a port communicating with the
retort or generator at the upper side of the furnace thereof and the other a port
communicating also with the retort at the under side of the furnace. The valves
are carried on the same spindle, and accordingly as the latter is caused to move
upwards or downwards by a handle or hand wheel, one of the ports is closed and
the other opened. Thus the air from the pump passes either over the furnace or
up through it and is heated and expanded correspondingly, and passing into the
working cylinder actuates the piston in a proportionate degree.
This invention relates, fifthly, to the arrangement of and method of operating
the admission and exhaust valves of the working cylinder of the engine. These
are enclosed in a chest connected to the cylinder by a throat or passage through
which the hot air from the admission valve passes and through which also the spent
air to the outlet valve is ejected. Thus the throat or passage is prevented from
being unduly heated. In order to keep the admission valve cool, the cold air, as it
passes from the pump to the governor valve, is admitted to an air-space around
the said admission valve.
The valves are alternately opened and closed by means of tappets attached to
the upper ends of their spindles which tappets are acted upon by a cam so formed
as to gradually raise and lower the valves. Thus the admission valve is prevented
from being forced into its seat by the pressure of the air above it. Noise from
this cause is consequently subdued. The outlet valve is arranged to work
downwards from the underside of the valve plate and is free to be opened by
the air outside it in event of a vacuum occurring in the cylinder. The area of the
outlet valve is such that a vacuum is thereby readily destroyed.
The passage of cinders into the valve chest or cylinder may be prevented by
placing a grating or perforated screen over the mouth of the supply pipe in the
retort or generator; and by a door fitted in the side of the retort at or near the
point where the supply pipe leaves it the cleaning of the said pipe and the socket
in which it is held in the retort is facilitated.

page_text: I, HENRY LONG, of 12, Armoury Square, Stapleton Road, in the City and
County of Bristol, Engineer, do hereby declare the nature of my said invention
for "IMPROVEMENTS IN CALORIC 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, firstly, to means employed for regulating the supply of
air to the retort or generator, and consists in the use of a receiver or reservoir
intervening between the said retort and the air pump. The receiver or reservoir is
placed in any convenient position and is charged from the pump through a double
seated equilibrium valve conveniently situated on the cover of the pump. It may
be situated elsewhere, if desired. Thus a constant and regular supply of air for
actuating the piston of the working cylinder is provided, and spasmodic and
irregular working of the engine, due to the absence of such receivers in the engines
as hitherto constructed, obviated.
The double seated equilibrium valve aforesaid constitutes a second improvement
effected under this invention. It is of annular form and presents a reduced bearing
surface for the pressure of the compressed air re-acting upon it from the receiver
or reservoir. Being provided with two orifices a shortened vertical travel or lift
suffices for the outlet of the air. By the use of the valve so constructed the impact
between it and the seats is lessened and noise consequently subdued.
Governing the admission of the air from the receiver or reservoir to the retort or
generator is a valve similar in construction to the pump valve before described.
This valve is operated by the governor, the movable vertical spindle of which
takes, at its lower end, into a socket formed in the upper end of a spindle the
lower end of which is secured to the valve. To the socket is attached one end of
a lever carrying, at the other end, a counterweight the normal tendency of which.
is to maintain the inside of the bottom of the socket against the lower end of the
governor spindle and thereby enable the governor to operate the valve. By means
of a regulating screw placed between the counterweight and the fulcrum of the
lever the valve may be operated to close, and thus to arrest the working of the
engine independently of the action of the governor. This cut-off arrangement
constitutes a further improvement effected under the said invention.
A fourth improvement relates to a further means of controlling the engine
independently of the action of the Governor.
It consists in the employment of a pair of conical valves which are capable of
operation by hand. One of these valves controls a port communicating with the
retort or generator at the upper side of the furnace thereof and the other a port
communicating also with the retort at the under side of the furnace. The valves
are carried on the same spindle, and accordingly as the latter is caused to move
upwards or downwards by a handle or hand wheel, one of the ports is closed and
the other opened. Thus the air from the pump may be directed to pass into the
retort either above or below the fire becoming heated and expanded correspondingly,
and passing into the working cylinder actuates the piston in a proportionate
degree.
This invention relates, fifthly, to the arrangement of and method of operating
the admission and exhaust valves of the working cylinder of the engine. These
are enclosed in a chest connected to the cylinder by a throat or passage through
which the hot air from the admission valve passes and through which also the spent
air to the outlet valve is ejected. Thus the throat or passage is prevented from
4

page_text: being unduly heated. In order to keep the admission valve cool, the cold air as it
passes from the pump to the governor valve, is admitted to an air space around the
said admission valve.
The valves are alternately opened and closed by means of tappets attached to
the upper ends of their spindles, which tappets are acted upon by cams so formed
as to gradually raise and lower the valves. Thus the admission valve is prevented
from being forced into its seat by the pressure of the air above it. Noise from this
cause is consequently subdued. The outlet valve is arranged to work downwards
from the underside of the valve plate and is free to be opened by the air outside it
in event of a vacuum occurring in the cylinder. The area of the outlet valve is 1
- such that a vacuum is thereby readily destroyed.
The passage of cinders into the valve chest or cylinder may be prevented by
placing a grating or perforated Screen over the mouth of the supply pipe in the
retort or generator; and, by a door fitted in the side of the retort at or near the
point where the supply pipe leaves it, the cleaning of the said pipe and the socket
in which it is held in the retort is facilitated.
And in order that my said invention may be properly understood, I now proceed
to describe the same with reference to the accompanying sheets of illustrativo
drawings and the figures and letters marked thereon.
Fig: 1, Sheet 1, of the drawings, represents a side elevation of a caloric engine
having the improvements constituting my said invention applied thereto. Fig: 2,
is a view from the same side as Fig 1 and is partly in vertical section. Figs 1
and 2, sheet 2, are respectively a plan and end view of the engine.
As the piston of the air pump A descends,) the air is admitted by the ordinary air
valves a¹ (see Fig 1, Sheet 2.) to the pump cylinder and is pumped thence as the
piston ascends, through the valve a (see Fig 2, Sheet 1.) situated in the chamber a²
conveniently carried on the cover of the pump A, and by the pipe B into the
receiver or reservoir C which may be conveniently situated below the retort D, as
shown. By thus storing the air a constant and regular supply is afforded for
actuating the piston in the working cylinder E, and hence spasmodic and irregular
working of the engine is obviated.
At Figs 5 and 6, sheet 1 are shown detached views of the valve a through which
the air is pumped from the air pump A into the pipe B.
Fig: 5 shews the valve raised and Fig: 6 is a plan of the fixed double seat. The
valve is of annular form and is provided with two seats e and e¹ the doudle seating
being fitted into the cover of the air pump A and surmounted by the fixed guard f
the top of which is dotted or perforated. The wings e³ of the valve seating serve
as guides for the valve. At Fig 2, Sheet 1, the valve a is shown closed.
As the piston of the air pump A ascends, the valve a is forced upwards from the
seats e e¹ and the air passes out below and above it to the pipe B. After contact
of the valve with the guard ƒ such air as has not otherwise escaped passes out
through the perforations in the top of the guard. By discharging the air below
and above the valve the latter is constituted an equilibrium valve, and a shortened
vertical travel suffices for the discharge of the air.
The force of impact between the valve and its seats is lessened and noise is
consequently reduced. The valve presents a small bearing surface to the com-
pressed air re-acting upon it from the receiver or reservoir C.
From the retort D the air is led by the pipe D¹ to the valve chest N and
circulates round an air space o therein, as hereinafter farther mentioned.
By the pipe F which opens into the valve chest at a point on the opposite side
to that at which the pipe D¹ is connected the air is conducted from the valve
chest N to the retort D.
In the pipe F is an equilibrium valve b contained in the chamber b¹ and operated
by the governor g (See Fig. 2, Sheet 1.)
A detached view of this valve and the governor is shown at Fig. 3, sheet 1.
The governor spindle c takes at its lower end into a socket formed in the upper
end of the spindle o' the lower end of which is secured to the valve b. Towards

page_text: its upper end the spindle c' is connected to one end of the lever h pivotted to the
governor bracket and provided at the other end with the balance weight h¹ tho
normal tendency of which is to maintain contact between the bottom of the socket
of the valve spindle c' and the lower end of the spindle c thus enabling the governor
to operate the valve. Between the fulcrum of the lever and the balance weight h¹
is a regulating screw i, seen more particularly in the enlarged view shewn at Fig. 4,
sheet 1.
By turning the nut accordingly, the weight h¹ may be tilted to close the
valve b and arrest the working of the engine independently of the governor g.
From the valve b the air passes through the pipe F1 to the conical valves k and k¹
enclosed in the chamber K secured to the side of the retort D. (See Fig. 2. Sheet 1).
The valves k, klare fixed on the same spindle ; and are raised or lowered by
turning the hand-wheel 1 accordingly.
The valve k controls the admission of air through the port u which cominu-
nicates with the space v between the lining V and the casing V₁ of the retort.
This space v extends to below the grate w.
The valve controls the admission of air through the port u³ which commu-
nicates direct with the central chamber of the retort.
Thus the air may be directed to pass into the retort either above or below the
fire, and, accordingly, the degree to which it is heated and expanded may be thus
further regulated and the working of the engine thereby controlled.
The valve m by which the air is admitted to the working cylinder E, and the
valve n through which the air is exhausted therefrom, are enclosed in the valve
chest N connected to the cylinder E by the throat l.
The valve spindles m¹ and n¹ are furnished towards their upper ends with the
tappets p and p¹.
On the driving shaft Q are carried the cams q and q².
The valve m is caused to rise by the cam q acting upon the tappet p and thereby
lifting the spindle m¹.
The heated air conducted from the retort D through the pipe M passes into the
cylinder E through the throat 7 and impels the piston upwards.
A spiral spring having one end secured to the spindle m¹ and the other to the
engine framing may be employed to maintain contact between the underside of the
tappet p and the cam q.
In the continued rotation of the cam g the valve m is lowered and the air supply
cut off. When the piston has reached the end of its upward stroke the valve n,
which opens downwards, is depressed by the cam q¹ acting on the tappet p¹
formed on the spindle n¹, and the spent air issuing from the cylinder E by the
throat escapes at the valve n and thence through the outlet r.
A spiral spring (not shewn in the drawings) having one end secured to the top
of the spindle n¹ and the other to the engine framing is employed to raise the
valve n into its seat before the valve m is opened to readmit air to the undersido
of the piston of the working cylinder E. The cam q¹ governs the upward motion
of the valve n. Antifriction rollers may be fitted in the tappets p and p² to bear
upon the cams q, q³. By the arrangement and operation of the valves as above
described the throat is prevented from becoming unduly heated and the valves
are prevented from being suddenly forced into their seats by the compressed air.
Noise arising from this latter cause is consequently lessened and tear and wear
reduced.
Should a vacuum occur in the working cylinder E, the valve n opens and
destroys it.
The admission valve m is partially surrounded by an air space o to which cold
air as it passes from the reservoir C to the governor valve b is admitted as herein-
before mentioned. The valve m is thus kept cool.
The passage of cinders from the retort D to the valve chest N is prevented by a
perforated screen placed over the mouth of the supply pipe M in which is also
fitted a door t, whereby ready access is obtained to the pipe for cleaning the same.

page_text: Having now particularly described and ascertained the nature of my invention,
and in what manner the same is to be performed, I declare that what I claim is :-
1st The employment, in a caloric or hot air engine, of a reservoir or receiver, for
the reception of a supply or store of air, situated between the air pump and the
retort or generator, whereby greater regularity in the working of the engine is
obtained, substantially as hereinbefore described and with reference to the accom-
panying sheets of drawings.
2nd The double seated equilibrium valve a constructed as described whereby the
air is delivered from the air pump, the said valve being arranged substantially as
described and as illustrated on Sheet 1 of the drawings.
3rd The equilibrium valve b operated through the governor g and acted upon
by the balance weight h¹ through the lever h or its equivalent whereby the
supply of air to the engine is governed and its speed controlled or its working
arrested, substantially as described.
4th The screw device m in connection with the lever h and balance weight h¹,
or their equivalents, whereby the governor valve b may be operated independently
of the action of the governor g substantially as described.
5th The use in a caloric engine of the valves k k³, or of valves analogous thereto
whereby the air may be conducted above or below the fire in the retort D and
the expansion of the air varied, substantially as hereinbefore described and illus-
trated at Fig. 2, Sheet 1 of the drawings.
6th The disposition of the admission valve m and the exhaust valve n whereby
the air is admitted to and exhausted from the working cylinder of the engine
through the same port and whereby the exhaust valve n is free to open to destroy
any vacuum created in the working cylinder, substantially as herein before described
and illustrated at Fig 2, Sheet 1, of the drawings.
7th Operating the valves m and n by means of the cams q, q', tappets p, p¹ and
mechanism connected there with acting in the manner described for admitting
heated air to and exhausting spent air from the cylinder E whereby noise is
lessened and tear and wear reduced.
E
n
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