IMPROVEMENTS IN CALORIC ENGINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said John Buckett at the Office
of the Commissioners of Patents on the 2nd May 1882.
JOHN BUCKETT of Gravel Lane, Southwark in the County of Surrey Engineer
"IMPROVEMENTS IN CALORIC ENGINES
"
My invention has reference to improvements in calorie engines of the kind
described in the specification of Letters Patent granted to J and W. T. Buckett
dated 14 November 1876 No 4418.
It has been found that in such engines when hot air on its way from the retort
to the working cylinder is suddenly stopped by closing of the valve there results
an acccession of heat the action of which upon the valve is such as to necessitate
the working of the engine at a comparatively slow speed.
To obviate this inconvenience according to my present invention I form around
and about the valve and its seating a space or chamber into, and through which
atmospheric air forced by the pump is, on its way to the retort, caused to pass so
as to take up and utilize a portion of the heat above referred to and prevent
excessive heating of the valve. The air chamber or space surrounding the valve and
its seating forms practically an intermediate part of the air feeding pipe or conduit
so that at each stroke of the engine, the pump delivers a stream of cold air into it,
for the purpose mentioned.
To enable admission of hot air from the retort to the working cylinder to be
automatically regulated and cut off by the action of a governor I apply to the slide
bar or other portion of the valve motion, a sliding or moving piece arranged to be
operated by the governor as and when the latter is affected by changes in speed of
the engine so that according to the position of the sliding or moving piece the
valve can be closed at any portion of the stroke. In connection with the said
71

page_text: sliding piece I provide means for regulating the cutting off by the governor of the
supply of heated air to the working cylinder so that this may be effected at the
desired point in the stroke of the pistons. To effect stopping and reversing of
the engine I provide upon the crank shaft or other revolving shaft cams or
projections so arranged as to engage with levers or rods and operate the inlet and
outlet valves of the engine as required.
Various arrangements may be employed, according to one plan a sliding part
carries the projections and the arrangement is such that in one position of the
sliding part its projections will be clear of the projections or parts through which
the inlet and exhaust valves are operated and the engine will be stopped. If now
the sliding part be moved from this position in one direction two projections will
respectively engage with the levers connected with the inlet and exhaust valves
and the engine will be worked so that the direction of motion of its crank will be
Bay from right to left. If the sliding part be moved in the contrary direction
two other projections will be brought into operation and actuate the valves at a
different period of time so as to cause the engine to be reversed and to work from
left to right.
To obviate or lessen noise occurring on the closing of the valves I provide means
whereby elastic fluid such as air is compressed in a cylinder furnished with a
plunger connected with the valve motion in such a manner that when the valve is
about to close the fluid in the said cylinder being then compressed is caused to
offer the necessary resistance just before the actual closing of the valve thus
preventing the valve from forcibly striking its seating.
In the specification before referred to there is described a conical fuel feeding
valve used in charging the retort.
According to my present invention to obviate liability to escape of hot air from
the retort into the fuel chamber that might arise if the valve should be imperfectly
closed owing to its supporting chain not being at all times perfectly central I
form the said valve of a combined conical and partially spherical form such that
whilst the upper part will afford the same facilities for distributing the fuel upon
the fire and preventing the accumulation of dust or pieces of fuel likely to interfere
with its closing, the lower or spherical part, fitting closely against its seating will
prevent escape of hot air, notwithstanding that the valve axis may be out of the
perpendicular
In the before mentioned specification there is described an arrangement of
governor by which a portion or the whole of the air can be passed either through
the fire or over the fire thus regulating the heat.
Now according to my present invention the governor is made capable of
performing not only the function just mentioned but also that of discharging a
portion of the air when the engine exceeds its normal speed, and that of operating
the valve connections so that the heated air can be cut off from the working
cylinder at any portion of the pistons stroke. To discharge the air I provide in
the valve spindle a slot or slots or grooves or channels so situated and arranged
that when the governor moves the spindle beyond a given point the air will be
free to escape.
To operate the valve connections I provide levers or bars so
arranged that the governor as it is influenced by change of speed will raise or
draw a connecting rod or lever more or less away from the cam used for operating
the valve by which means the inlet valve will be made to close sooner or later
and so cut off or admit the heated air to the cylinder in the desired quantity and
at the time wished According to another part of my invention in order when
stopping the engine to accumulate pressure that can be afterwards utilised for
restarting the engine or when extra power is required I provide means whereby
communication is closed between the retort and the working cylinder so that the
supply of heated air to the working cylinder will be stopped but the air pump will
be allowed to keep in action so long as the momentum left in the engine is sufficient
to overcome the pressure.

page_text: In some cases where the work is unequal such as in tram or traction engines,
power cranes, winding engines, and the like I provide an additional air receiver or
vessel which is charged with compressed air either by the action of the engine
pump or by an additional pump provided for that purpose.
Thus when the engine is not required to develope its fall amount of work its
surplus force can be used to create reserved pressure and the force so stored can be
used when extra work has to be performed by the engine. It will be evident
that by this part of my invention not only can force be stored up for subsequent
use but as the air pump works whilst the working piston receives no energy the
Baid pump offers resistance to the momentum of the engine and acts as a brake-
so that for tram engine or such purposes the ordinary brake power could be
dispensed with or reduced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Buckett in the Great Seal Patent Office on the 2nd November
1882.
JOHN BUCKETT of Gravel Lane Southwark, in the County of Surrey Engineer,
IMPROVEMENTS IN CALORIC ENGINES
My invention has reference to improvements in caloric engines of the kind
described in the specification of Letters Patent granted to J and W. T. Buckett
dated 14 November 1876 No. 4413
It has been found that in such engines when hot air on its way from the retort
to the working cylinder is suddenly stopped by closing of the valve there results
an accession of heat the action of which upon the valve is such as to necessitate
the working of the engine at a comparatively slow speed.
To obviate this inconvenience according to my present invention, I form around
and about the valve and its seating a space or chamber into and through which
atmospheric air forced by the pump is on its way to the retort caused to pass so as
to take up and utilize a portion of the heat above referred to and prevent excessive
heating of the valve.
The air chamber or space surrounding the valve and its seating forms practically
an intermediate part of the air feeding pipe or conduit so that at each stroke of the
engine, the pump delivers a stream of cold air into it for the purpose mentioned.
To enable admission of hot air from the retort to the working cylinder to be
automatically regulated and cut off by the action of a governor I apply to the slide
bar or other portion of the valve motion, a sliding or moving piece arranged to be
operated by the governor as and when the latter is affected by changes in speed of
the engine so that according to the position of the sliding or moving piece the
valve can be closed at any portion of the stroke.
In connexion with the said sliding piece I provide means for regulating the
cutting off by the governor of the supply of heated air to the working cylinder 80
that this may be effected at the desired point in the stroke of the piston.
To effect stopping and reversing of the engine I provide upon the crank shaft or
other revolving shaft cams or projections so arranged as to engage with levers or
rods and operate the inlet and outlet valves of the engine as required.
Various arrangements may be employed: according to one plan a sliding part
carries the projections and the arrangement is such that in one position of the
sliding part its projections will be clear of the projections or parts through which
the inlet and exhaust valves are operated and the engine will be stopped.
If now the sliding part be moved from this position in one direction two
projections will respectively engage with the levers connected with the inlet and
exhaust valves and the engine will be worked so that the direction of motion of its
crank will be, say from right to left.
If the sliding part be moved in the contrary direction two other projections will
be brought into operation and actuate the valves at a different period of time so as
to cause the engine to be reversed and to work from left to right.
To obviate or lessen noise occurring on the closing of the valves I provide means
whereby elastic fluid such as air is compressed in a cylinder furnished with a
plunger connected with the valve motion in such a manner that when the valve is
about to close the fluid in the said cylinder being then compressed is caused to
offer the necessary resistance just before the actual closing of the valve thus
preventing the valve from forcibly striking its seating.
In the specification before referred to there is described a conical fuel feeding
valve used in charging the retort,

page_text: According to my present invention to obviate liability to escape of hot air from
the retort into the fuel chamber that might arise if the valve should be imperfectly
closed owing to its supporting chain not being at all times perfectly central, I form
the said valve of a combined conical and partially spherical form such that whilst
the upper part will afford the same facilities for distributing the fuel upon the fire
and preventing the accumulation of dust or pieces of fuel likely to interfere with
its closing, the lower or spherical part fitting closely against its seating will
prevent escape of hot air, notwithstanding that the valve axis may be out of the
perpendicular.
In the before mentioned specification there is described an arrangement of
governor by which a portion or the whole of the air can be passed either through
the fire or over the fire thus regulating the heat.
Now according to my present invention the governor is made capable of
performing not only the function just mentioned but also that of discharging a
portion of the air when the engine exceeds its normal speed, and that of operating
the valve connexions so that the heated air can be cut off from the working
cylinder at any portion of the piston's stroke.
To discharge the air I provide a slot or slots or grooves or channels so situated
and arranged that when the governor moves the spindle beyond a given point the
air will be free to escape.
To operate the valve connexions I provide levers or bars so arranged that the
governor as it is influenced by change of speed will raise or draw a connecting rod
or lever more or less away from the cam used for operating the valve by which
means the inlet valve will be made to close sooner or later and so cut off or
admit the heated air to the cylinder in the desired quantity and at the time
wished. According to another part of my invention in order when stopping the
engine to accumulate pressure that can be afterwards utilized for restarting the
engine or when extra power is required, I provide means whereby communication
is closed between the retort and the working cylinder so that the supply of
heated air to the working oylinder will be stopped but the air pump will be
allowed to keep in action so long as the momentum left in the engine is
sufficient to overcome the pressure. In some cases when the work is unequal
such as in tram or traction engines power cranes winding engines and the like
I provide an additional air receiver or vessel which is charged with compressed air
either by the action of the engine pump or by an additional pump provided for
that purpose.
Thus when the engine is not required to devalope its full amount of work its
surplus force can be used to create reserved pressure and the force so stored can be
used when extra work has to be performed by the engine.
It will be evident that by this part of my invention not only can force be stored
up for subsequent use but as the air pump works whilst the working piston
receives energy the said pump offers resistance to the momentum of the engine
and acts as a brake so that for tram engines or such purposes the ordinary brake
power could be dispensed with or reduced.
Referring to the annexed sheets of drawings Figure 1 is a side elevation of my
improved caloric engine.
Figure 2 is an elevation at right angles to Figure 1 and Figure 3 is a plan.
a is the retort formed of fire brick and surrounded by an annular air space a¹
into which a portion of the air from the air pumps b b is delivered by means of
the pipes 6' b¹ and the central pipe a
The pipe o has two branches c' e' leading respectively to the annular space a³,
and to the top a³ of the retort a the proportion of air passing through each branch
being regulated by the hollow cylindrical valve d operated by the governor e as
shewn in Figure 1.
The air which passes through c¹ and around the air space a' descends to beneath
the fire place of the retort and passes through the fuel as shewn by arrows.
The air that is delivered through the branch of is conducted to the upper part of

page_text: the retort (as also indicated by arrows) where it enters into combination with the
carbonic oxide as already explained.
The heated high pressure gas is admitted from the retort to the working
cylinders ff by the valves g g operated from the crank shaft and escapes by
means of the exhaust valves ff operated in a similar manner to the valves g 9.
E
The hollow cylindrical valve d is so arranged with respect to the branches c¹³,
that when the engine slackens speed, and the governor consequently falls, the said
valve is raised thus allowing a greater proportion of the air to pass through o¹ into
the air space a¹, and up through the incandescent fuel, and at the same time
allowing a smaller proportion of air to pass through o' to the combustion chamber; 1
thus the consumption of fuel is regulated in proportion to the amount of power
given out by the engine.
As the atmospheric air from the pumps b b is forced through the pipes b' b' and
c to the retort a it is caused to pass through a space or chamber g¹ (shewn in
section Figure 4 and in plan Figure 5) formed around and about each of the valves g
so as to take up and utilize a portion of the heat evolved from the hot air (on its
way to the cylinders ƒƒ) when that hot air is suddenly stopped by the closing of
the said valves. Excessive heating of the said valves g g is by the just described
arrangement prevented.
When the valve which controls the admission and exhaustion of actuating 2
fluid to and from the working cylinder is kept cool as above described by the
incoming air from the pump the distribution may if desired be effected by a slide
valve.
An arrangement for this purpose is illustrated in Figures 15 to 26 inclusive.
Figure 15 is an elevation of the valve face on the cylinder.
Figure 16 is a half section in line A B Figure 15.
Figure 17 is a half section in line CD Figure 15.
Figure 18 is a section in line E F,-Figure 15.
Figure 19 is a plan of the valve chest.
Figure 20 is an end view of the valve.
Figure 21 is a side view of the valve face.
Figure 22 is a view of the valve chest.
Figure 23 is an elevation of the cam for actuating the valve.
Figure 24 is a section of the same in line A B. Figure 23.
Figure 25 is a side elevation of the cam, and the slide rod with its roller and
guide bracket, and Figure 26 is a plan of the guide bracket.
B is the slide valve working on the face B¹ and pressed down by the adjustable
spring B³ and screw B³
It is moved by the slide rod c (Figure 25) passing through the stuffing box c²
and operated by the cam D.
This rod reciprocates in a guide C¹and carries a roller D¹ which runs in a groove
in the face of the cam.
The valve has three ports E E' E of which E is in communication with the
retort, E' with the cylinder and E with the exhaust pipe.
At one end of the valve face there is a channel F through which the cold air
entering at F from the pump and leaving at F to the retort circulates.
At the opposite end there is a second channel F³ to which the cold air has also access.
The length of the valve face is such that a part of the valve overhangs it at
each end of its travel and is open to the action of the cold air on all sides.
Thus the valve chest constitutes a part of the air way or passage between the
pump and the retort and accession of heat in the valve and its seating is obviated.
Figure 6 is a side elevation, Fig. 7 an end elevation and Figure 8 a plan of the
valve motion by which the admission of hot air from the retort to the working
cylinders ff is automatically regulated and cut off by the action of the governor.
There is a separate arrangement for each cylinder both being controlled by the
same governor.
As the two arrangements are identical, the same description will apply to each.
4

page_text: h is a bar pivotted at one end of the link h' and at the other end to the lever hª
which operates the valve spindle i
In the bar h there slides a moving piece j connected by levers and links. to the
governor and bearing against a supporting piece ha on the bar h.
The sliding piece ; is connected to the link by a screw connexion j³ for
adjusting its length.
By this device the point of maximum cut off can be regulated.
As the crank shaft revolves in the direction of the arrow (see Fig. 16) it carries
round with it the cam or tappet k which coming against the sliding piece j moves
the bar h and operates the valve spindle i through the bell crank h³.
If the speed of the engine be increased the governor lifts the sliding piece ; so
that the cain or tappett & leaves it sooner and allows the valve spindle & to descend
and the inlet valve to close and cut off the flow of hot air to the cylinder at an
earlier point of the stroke.
l
The handle or lever is provided for the purpose of stopping the engine, it is
pinned loosely on the shaft or spindle m and when lifted it raises both pieces j
clear of the cam or tappet ke by means of the bar or spindle n.
This spindle rests upon the lever and is carried in two arms n¹ n' pivotted
loosely on the shaft mit projects at each end underneath the arms m³ m³ in such
a way that when raised it also raises the said arms, and with them the sliding
piece j.
The lever m³ is keyed on the rock shaft m and moves it in accordance with the
rise and fall of the governor arms.
The levers m* are also keyed to the same shaft and transmit its motion to the
levers m m which are connected by the links to the sliding pieces j. j.
The effect of this arrangement is that when it is desired to raise the sliding
pieces by the hand lever this can be done without any alteration in position of
the governor balls, since the levers m² m² are free to be moved away from the
levers m*.
In order to start the engine it is necessary to open the inlet valve of one of the
cylinders, and for this purpose the hand lever o is provided.
It works loosely on the shaft p and is capable of being slidden along it so that
it can he made to actuate either valve rod or i¹ through the link or lever h'
sliding bar h and lever hand one of the projecting pieces of 0.
The reversing arrangement is shown separately for the sake of clearness in
front elevation in Figure 9, in end elevation in Figure 10 and in plan in
Figure 11. In these figures the governor and the mechanism for effecting the
automatic cut off are omitted.
The cams or tappets are carried by sliding pieces on the crank shaft.
Each sliding piece is connected to the shaft by a feather key and is provided
with a groove into which two clutch fingers forming part of a clutch lever project.
Both clutch fingers are connected to the handle g and when the handle is moved
out of its mid-position both sliding pieces are carried along the shaft in the same
direction so that one tappet on each of them say the tappets marked & will come
into gear with the corresponding piece on the bars or levers h and will operate
the valve spindles, i at such times that the engine is caused to turn in one
direction.
If the handle g be moved in the other direction the sliding pieces will be moved
so that the other set of tappets k' kare brought into gear with the piece j.
The handle is connected to the clutch levers through the intermediary of
springs 88 in order that if the motion be made at a time when one of the tappets
will strike the side of the piece ; and cannot pass in front of it, yet the other may
take up its position without delay.
To obviate or lessen the noise occurring on the closing of the valves ga cylinder g³
(shewn in section Figure 12 and in plau Figure 13) fixed to the valve casing is
fitted with a plunger g³ connected to the rocking lever h³ which works the valve
spindle i

page_text: In the plunger g³ is a valve g open inwards so that as the plunger rises when
the valve g (see Figure 4) is opened air rushes in beneath the plunger.
As the rocking lever his depressed so as to close the valve g it also forces
down the plunger g³ thus compressing the air beneath it, which escapes up the
aperture g³
This air acts as a cushion and offers the necessary resistance just before the
actual closing of the valve g thus preventing it from forcibly striking the seating.
The amount of resistance offered by the air to the plunger may be varied by
increasing or diminishing the size of the escape aperture g³.
a² Figure 1 is a fuel chamber fixed to the top of the retort a whereby fuel is
fed to the retort by means of a valve a³ shewn in section in Figure 14.
To ensure the tight fitting or closing of the valve against its seating so as to
prevent the escape of hot air from the retort into the fuel chamber, owing to the
supporting chain a' not being at all times perfectly central, and so canting the
valve; the said valve is formed of a combined conical and partially spherical shape,
such that whilst the upper or conical part affords the facilities for distributing the
fuel upon the fire and preventing the accumulation of dust or pieces of fuel likely
to interfere with its closing, the lower or spherical part prevents the escape of hot
air as before mentioned. The lower part of the valve is protected by a shield a*
(Figure 1).
On stopping the engine its momentum can be expended in forcing air from the
pump into the retort, or into a separate receiver.
Or a separate pump (Figure 1) may be worked from the crank shaft to force
air into a receiver w connected by a valve a to the retort.
This pump is capable of being thrown in and out of gear at will according to
the useful load on the engine.
The accumulated pressure of the air in the receiver w may be directed into the
fire place of the retort ready for again starting the engine or direct to the cylinder.
In the case of tramway engines and the like the resistance offered by the pump in
accumulating the said pressure may act as a brake to stop the vehicle.
Figure 27 illustrates in vertical section to an enlarged scale an arrangement
according to my invention for discharging a portion of the cold air when the engine
exceeds its normal speed so that when the engine is not developing its full power,
only a part of the cold air compressed by the air pump is allowed to enter the
retort are the two branch pipes that lead respectively to the annular space a¹
(hereinabove described) and to the top of the retort, and d is the hollow cylindrical
valve operated by the governor e (not shown in this view) and which regulates the
proportion of air passing through each of the said branch pipes o¹ c² e¹ is a
prolongation of the governor spindle which at its lower end acts a valve for which
purpose it has formed in it a slot, groove or channel e³ (or there may be several)
and this part of the spindle extends through a passage formed through the lower end
of the valve box as shewn so that when the speed of the engine becomes so great
that the governor arms cause the spindle e' to move down sufficiently to bring the
lower end the alot, groove or channel below the outer surface of the bottom of
the valve box then air from within the said box will be permitted to escape by e³
Figure 28 shews a modification of the just described arrangement according to
which instead of making the governor spindle e' with a groove e a part e³ of that
spindle is made of reduced diameter so that the lower end of the spindle will act
as a valve as described with reference to the preceding arrangement as will be
readily understood.
Figure 29 shews another arrangement. In this case the air is discharged through
a valve opened by the governor spindle in opposition to a spring e³.
In the modification shewn in Fig. 30 the governor spindle operates the valve e
through the lever e and spindle e to discharge the cold air.
Having thus described the nature of the said invention and the manner in
which it is to be performed I would have it understood that what I consider to be

page_text: novel and original and therefore claim as secured to me by the Letters Patent
bereinbefore first in part recited is :-
1. In a caloric engine preventing excessive heating of the distributing valve by
providing around and about such valve and its seating, or the face on which it
slides, a chamber, or space and causing atmospheric air to pass into such chamber
or space on its way to the retort so as to take up a portion of the heat evolved at
the said valve as hereinabove explained, whether the arrangement be substantially
such as shewn in and described with reference to Figures 4 and 5 of the drawings,
or such as shewn in and described with reference to Figures 15 to 22 inclusive of
the drawings.
2. In a caloric engine the use for fixing the point of maximum or latest cut off
of actuating fluid to the working cylinder, of a sliding or movable piece subject
to the action of a cam or tappet and capable of being set or adjusted by hand
substantially as described.
3. In a caloric engine automatically regulating the inlet of actuating fluid to the
working cylinder, by means of a sliding or movable piece such as ; adjusted by a
governor and working in conjunction with a cam or tappet in such a manner that
the said sliding or movable piece remains in contact with the said cam or tappet
during a longer or shorter portion of the pistons stroke, according to requirement,
substantially as described with reference to Figures 6, 7 and 8 of the drawings.
4. In a caloric engine the use in combination of a sliding or movable piece
normally subject to the action of a cam or tappet for the purpose of operating the
inlet valve of the cylinder, and mechanism whereby the said piece may be withdrawn
from the action of the said cam or tappet to stop the engine substantially as
described.
5. In a caloric engine the use for reversing the direction of rotation of the engine
as well as for stopping its rotation, of a movable piece, and cams or tappets carried
on a single sliding piece or aleeve, one of the said cams or tappets being arranged in
the right position for the forward motion of the engine, and one in the right
position for the backward motion, of the engine, and the whole being so arranged
that either of the said cams or tappets can be set so as to act upon the movable
piece, or that both cams or tappets can be set clear of it, substantially as
described.
6. In a caloric engine such as hereinabove described the use in combination with
the retort a of the improved fuel feeding valve a constructed of a combined
conical and partially spherical shape as described and illustrated for the purpose
specified.
7. In a caloric engine the use of a receiver into which air is delivered by a pump
at such times as the full power of the engine is not required to be exerted on the
external work, or when the engine is driven by its own momentum, or by an
external force substantially as described.
8. In a caloric engine discharging a portion of the cold air by means of the
governor spindle when the engine exceeds its normal speed so that when the
engine is not developing its full power only a part of the cold air forced into
the valve box is allowed to pass to the retort substantially as described.
9. The improved caloric engine constructed arranged and operating substantially
as hereinabove described and illustrated.
In Witness whereof I the said John Buckett have hereunto set my hand
and seal this Second day of November in the year of our Lord one
thousand eight hundred and eighty two.