AN IMPROVED MEANS FOR PRODUCING MOTIVE POWER, AND THE MACHINERY OR APPARATUS EMPLOYED THEREFOR
Year: 1866

page_text: LETTERS PATENT to John Stuart Johnstone, of Blairlogie, in the County
of Perth, North Britain, Gentleman, for the Invention of "AN IMPROVED
MEANS FOR PRODUCING MOTIVE POWER, AND THE MACHINERY OR APPARATUS
EMPLOYED THEREFOR."
Sealed the 19th March 1867, and dated the 28th September 1866.
PROVISIONAL SPECIFICATION left by the said John Stuart Johnstone
at the Office of the Commissioners of Patents, with his Petition, on
the 28th September 1866.
I, JOHN STUART JOHNSTONE, of Blairlogie, in the County of Perth, 'North
Britain, Gentleman, do hereby declare the nature of the said Invention
of "AN IMPROVED MEANS FOR PRODUCING MOTIVE POWER, AND THE MACHINERY
OB APPARATUS EMPLOYED THEREFOR," to be as follows, that is to say:-
This Invention, which has for its essential, object the application of a
certain property belonging to metals as a means for obtaining motive power,
and the arrangement of apparatus for rendering such property capable of
producing considerable mechanical effect, consists as follows:-
It has long been known that when two bars of metal, of different expansive
powers are fastened together so as to produce a compound bar, that if such

page_text: compound bar has its temperature raised the bar itself assumes a form more
and more curved as the temperature is raised, and regains its original straight
form as soon as the temperature is lowered to the original temperature; this
property then is what is employed under this Invention as the means for
obtaining motive power..
The apparatus which is employed for carrying this Invention into effect
consists of a metallic framework fixed to a strong bed plate and a firm end
bearing piece. The framework contains several sets of compound bars or
plates (preferably composed of brass and iron); these compound bars or
plates are arranged in the framework in rows parallel to each other, each bar
or plate having a short space between itself and the adjacent bar or plate, the
two bars or plates bearing at their central parts on a piece of metal. In the
apparatus each compartment or set of these compound bars or plates is
situated each with the bars or plates reversed to that compartment or set
which immediately precedes it, that is to say, if in the first compartment or
set the compound bars or plates are arranged with the brass facing in a right-
hand direction and the iron side in a left-hand direction, in the second or
next compartment they are sitnated with the brass in a left-hand direction
and the iron in a right. The object of this arrangement is that on being
heated both bars may assume curved forms in exactly opposite directions. It
is now evident that as soon as a set of bars is heated, one end being firmly
supported against the bearer herein-before referred to, that on assuming the
curved form the unfixed end of the set will be projected forward to an extent
corresponding to the curvature of the plates; this movement immediately
acts upon a piece of metal situated between it and the first bar of the second
set; the second set being heated also, its plates or bars assume the curved
form and similarly act upon the third set, so that the second set is projected
forward twice the amount of the first set, the third three times that amount,
and so on for any number of sets of plates or bars, so that it is only necessary
to increase the number of sets or compartments of compound bars or plates to
obtain any length of stroke or motion. In arranging apparatus of this class two
chambers are employed, each one containing a separate arrangement of com-
partments or sets of plates, so that whilst one is being cooled the other is heated,
and in this way a return and forward stroke is alternately obtained; rods are
attached to the ends of the last series of compartments of the compound plates,
and are connected to levers or cranks for acting on spur wheels and shafts to
produce rotatory or other motion as may be required. The apparatus may be
fitted on an adjustable table, which may be raised or lowered so as to vary

page_text: the virtual length of the crank or lever on which the motive power acts. A
fan is used for cooling one chamber whilst the other is being heated, and
which is driven in the usual or other manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Stuart Johnstone in the Great Seal Patent Office
on the 27th March 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
STUART JOHNSTONE, of Blairlogie, in the County of Perth, North Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of September, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Stuart Johnstone, Her special license that I, the said John
Stuart Johnstone, my executors, administrators, and assigns, or such others.
as I, the said John Stuart Johnstone, my executors, administrators, or
assigns, should at any time agree with, and no others, from time to time.
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom.
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "AN IMPROVED MEANS FOR PRODUCING MOTIVE POWER, AND THE
MACHINERY OR APPARATUS EMPLOYED THEREFOB," upon the condition (amongst
others) that I, the said John Stuart Johnstone, by an instrument in writing.
under my hand and seal, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said Letters.
Patent.
NOW KNOW YE, that I, the said John Stuart Johnstone, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
.
My said Invention, which has for its essential object the application of a
certain property belonging to metals as a means for obtaining motive power,

page_text: and the arrangement of apparatus for rendering such property capable of
producing considerable mechanical effect, consists as follows:-
It has long been known that when two bars of metal of different expansive
powers are fastened together so as to produce a compound bar, that if such
compound bar have its temperature raised the bar itself assumes a form more
and more curved as the temperature is raised, and regains its original form
as soon as the temperature is lowered to the original temperature; this
property then is what is employed under this Invention as the means for
obtaining motive power.
The apparatus which is employed for carrying this Invention into effect
consists of a metallic framework fixed to a strong bed plate and a firm end
bearing piece. The framework contains several sets of compound bars or plates
(preferably composed of brass and iron); these compound bars or plates are
arranged in the framework in rows parallel to each other, each bar or plate
having a short space between itself and the adjacent bar or plate, the two
bars or plates bearing at their central parts on a piece of metal. In the
apparatus each compartment or set of these compound bars or plates is.
situated each with the bars or plates reversed to that compartment or set
which immediately precedes it, that is to say, if in the first compartment or
set the compound bars or plates are arranged with the brass side facing in a
right-hand direction and the iron side in a left-hand direction, in the second
or next compartment they are situated with the brass in a left-hand direction
and the iron a right. The object of this arrangement is that on being
heated both bars may assume curved forms in exactly opposite directions.
It is now evident that as soon as a set of bars is heated, one end being firmly
supported against the bearer herein-before referred to, that on assuming the
curved form the unfixed end of the set will be projected forward to an extent
corresponding to the curvature of the plates; this movement immediately
acts upon a piece of metal situated between it and the first bar of the second
set; the second set being heated niso, its plates or bars assume the curved
form and similarly act upon the third set, so that the second set is projected
forward twice the amount of the first set, the third three times that amount,
and so on for any number of sets of plates or bars, so that it is only necessary
to increase the number of sets or compartments of compound bars or plates to
obtain any length of stroke or motion. In arranging apparatus of this class
two chambers are employed, each one containing a separate arrangement of
compartments or set of plates, so that whilst one is being cooled the other is
heated, and in this way a return and forward stroke is alternately obtained.
Rods are attached to the ends of the last series of compartments of the

page_text: compound plates, and are connected to levers or cranks for actuating spur
wheels and shafts to produce rotatory or other motion as may be required.
The apparatus may be fitted on an adjustable table, which may be raised or
lowered so as to vary the virtual length of the crank or lever on which the
motive power acts. A fan is used for cooling one chamber whilst the other
is being heated, and which is driven in the usual or other manner.
And in order that my said Invention may be properly understood I now
proceed more particularly to set forth the system, mode, or manner in or
under which the same is or may be used or practically carried into effect,
reference being had, for the sake of more complete elucidation, to the several
Figures upon the two explanatory Sheets of Drawings which I have hereunto
appended, that is to say:-
On Sheet 1, Figure 1 is a side elevation of a motive-power engine con-
structed in accordance with my present Invention; in the Figure the outer
case covering the sets of compound bars is removed for the purpose of the
more distinctly indicating their arrangement. Figure 2 is an end elevation
corresponding to Figure 1.
Figure 3 (Sheet 2) is a general plan of the apparatus corresponding to
Figures and 2; the other views, Figures 4, 5, 6, 7, 8, and 9, are details
which will herein-after be more fully. referred to.
On referring to Figures 1, 2, and 3 it will be seen that the motive-power
engine now to be described consists of two sets of motive apparatus, marked
respectively A and A', on the cases containing the sets of compound bars.
The compound bars, one of which is shown on an enlarged scale at
Figures 8 and 9, are arranged in four parallel layers a, a¹, a², a³, as more
particularly shown at Figure 1, and these four layers are combined together
in two compartments, namely, compartment 1, marked B, and compartment 2,
marked C; each of the compartments B and C are again subdivided into
two different arrangements of the compound bars, that is to say, in the first
half of the compartment B the bars are arranged having the brass face at
the rere and the iron or steel face in the front, whilst the foremost half of the
same compartment is reversed, in having the iron side of the bars to the rero
and the brass side foremost; the second compartment C is similarly arranged.
The object of this mode of arranging the compartments is that on being
heated the bars of the first half of compartment B become curved in a
convex form towards the rere, and the front half of the same compartment
become convex in a forward direction, or, in other words, both ends of a
compartment become convex outwards, the consequence of which is that the
whole of the sets of compound bars are projected forward to an extent

page_text: corresponding to the amount of curvature. In the same way the second
compartment, or that marked C, on assuming a similar form to the preceding,
is similarly projected forward. It is to be understood that the heating of the
bars to cause them to assume the curved form takes place throughout all of
them simultaneously. From what has now been stated it is evident that by
employing several sets of these compound bars a stroke or movement
forward of any required length may be obtained, and also that on lowering
their temperature a corresponding backward stroke is the result. In this
way a continual succession of backward and forward strokes may be obtained,
similar to the reciprocations of the piston of a steam engine. The compart-
ments or sets of bars are held together in a framework consisting of horizontal
bars c, through all of which holes. are formed to exactly correspond with
each other; through these holes the bolts d are placed, passing at the same
time through the ends of each bar, which are bent round, as shown at
Figures 8 and 9, to enable them to be firmly held by the bolts in the frame-
work. The sets of bars constituting the motor are held to the abutment E by
the bolts and nuts e. At the centre each bars bears upon a vertical strip of
metal, as more particularly seen at Figure 3, and the two compartments bear
upon each other by means of the central bar f, carrying the bearing or contact
discs 9.
In this way the action and re-action of all the compound bars by
contact through the medium of these vertical bars is obtained. At the
bottom of the central bar a horizontal rod h is attached; it is fixed in the
bearings h, and the compartments by means of the bearing piece move back-
wards and forwards on it, and it is to be understood that in large engines a
similar bearing is or may be provided at the top side to prevent the compart-
ments buckling laterally. To the front end of the sets of compound bars the
rod F is attached as shown; this corresponds to the piston rod of an ordinary
steam engine, and it is supported in a suitable guide bearing H; to this rod is
coupled the connecting frame I, the form of which will be better understood
on reference to Figure 3. The frame carries the rings J, which are held
therein by swivel or trunnion joints, and these rings are the media by which
the rod F is coupled to the levers L and L', through which the reciprocating
motion of the rod F is converted into the rotatory movement of the other
parts of the machine to be herein-after described. It is of course to be under-
stood that what has been herein-before described in reference to one of the
compound bar motors applies equally to the other of these, namely, to those
parts encased within the coverings marked A and A¹ in Figure 2.
frame I is carried at its outer end in the bearing I¹ held by the bracket
frame I
The

page_text: I now proceed to set forth the manner in which the reciprocating movement
of the parts herein-before referred to is converted so as to cause rotation of
the driving shaft K. Supposing the shaft to be rotated in the direction
indicated by the arrows, each set of levers L and L' is provided with palls i,
two of which are applied to each lever as shown, one only of which is in
motion at one time, the other one being lifted and kept out of gear by meaus
to be herein-after described. The engine or apparatus seen in Figure 1 is
just commencing its forward stroke; and it may be here mentioned that the
two motors or engines are arranged to work in alternate directions, so that
whilst either one is performing a forward stroke the other is performing a
backward stroke. In carrying forward the levers L and L', the reremost of
them, L, has its front palli in gear with the teeth of the ratchet j, which is
firmly secured on the shaft k, this shaft also carrying a spur pinion gearing
into a similar spur pinion on the shaft m. In proportion, therefore, as the
lever L is pushed forward, to a corresponding extent is rotation imparted to
the shaft m on making the return stroke. The reremost palli on the lever L'
is in gear with the ratchet wheel fixed immediately on the shaft m, thus a
slow continuous rotation of the shaft m is obtained, and the two motors being
arranged to actuate the same shaft, it is of course driven by twice the amount
of power due to a single motor. In order to convert the slow rotation of the
shaft m into a rate of revolution sufficiently quick to render the engine a
convenient and useful motive power, this shaft is provided with a large spur
wheel M, which gears into a spur pinion, the shaft of which carries another
similar spur wheel N that actuates the pinion on the driving shaft K. In the
manner now last described then the reciprocatory movement of the motor is
communicated to the driving shaft. The shaft K is provided with a fly
wheel K', by which the motion is equalized, and it also carries the driving
pulley O, from which the belt O' passes, actuating the small belt pulley 0%,
the shaft of which carries the larger belt pulley 0%, which in turn actuates the
pulley O on the shaft of the fan contained within the fan case 0s; the use
of the fan will be herein presently described. The table carrying the motors
is fixed upon a framework capable of vertical adjustment in the main frame-
work, and it is elevated or lowered by the screw P, which is actuated from the
handle P through the shaft and bevil gearing Q. The lower end of the
screw shaft P is situated in a bearing attached to the bottom of the framework,
and the upper part passes into the nut P2, fixed to the lower table or plat-
form R, forming the under part of the framework carrying the motors proper;
this lower table R also constitutes the platform on which the lamp R¹ is
carried. According to the elevation or depression of the framework the

page_text: :
power of the engine may be developed at a slower or faster rate respectively,
in accordance with the virtual length for the time being of the levers L
and L.
Reference has been herein previously made to the apparatus for regulating
'the direction in which the main shaft K shall rotate. The means to this end
consist of the rod n, Figures 1, 2, and 3, to which are coupled the tumbling
links o and o¹, shown dotted in Figure 2; these links are provided with
cross bars at their upper ends, as shown, and are moveable about the pin
by which they are united to a joint bracket on the under side of the table.
Each end of the cross bars act on two of the vertical bolts P, the cross
bars having attached at each end the piece q, shown dotted in Figure 1, so
that according to the direction in which the rod n is pulled or pushed one end
of the cross bars is elevated and the other depressed, the elevated ends lifting
two bolts p, on which they are designed to act, thereby keeping the palls out
of gear with the ratchet wheels, whilst the palls on the opposite sides of the
levers L and L not being thus acted upon remain in gear with the ratchet
teeth, accordingly then with the position in which the rod n is fixed may the
engine be caused to revolve the main shaft either in a right or left hand
direction. The handle lever n' is attached to the rod by which it is actuated,
and the handle is also provided with a rack or its equivalent and a fixing pin,
by which its position is determined.
Having now described the chief parts of the engine or motor proper, I now
proceed to set forth the manner in which the alteration of temperature is
imparted to the sets of compound bars, by means of which the motive effect is
produced.
In the apparatus which I have constructed I employ a lamp R' as the
thermo-generator, although in a larger engine the heat of a furnace, ignited
gas, or other heat-producing means may be employed. The heat of the flame
passes up through the flue S into the valve chambers S1 and S2, one of which
is shut whilst the other is open, so that the heated air may pass therefrom into
one motor chamber only at a time.
In the Drawings, Figures 1, 2, and 3, the heated air is passing into the
chamber A', so as to expand or curve the sets or compartments of compound
bars therein, thereby causing them to perform the forward stroke; whilst the
heating of one of the chambers is going on, the cooling of the other chamber
'proceeds in the following manner :-To the fan case 0s containing the fan, which
is actuated in the manner herein-before described, is attached the blast pipe or
duct T, which is united to the vertical plate T¹, shown dotted in Figure 1,
scen also at Figure 2, and in detail at Figure 3, over which the movable flue

page_text: piece T is capable of sliding vertically. The blast from the fan is driven
through these ducts into the valve boxes U and U₁, and the mechanism
berein-after described for actuating the valves S and S, U and U is so
arranged that when one valve for admitting hot air to one of the chambers
A or A' is open the valve for admitting the cold air is shut, or that when the;
cold air valve is open the hot air valve is shut. The hot and cold currents as
soon as they arrive into the chambers below the sets of compound motor bars
pass into the chambers containing them through the openings o, o, Figure 1,
as indicated by the arrows, and after having either heated or cooled the sets
of bars the hot or cold air issues through the chimnies V.
In order to render the arrangement of the different chambers through
which the heating and cooling currents pass the better understood different.
separate views are given of the arrangement at Figures 4, 5, 6, and 7.
I now proceed to set forth the mechanism adopted for actuating the valves..
To the bed plate carrying the motor apparatus bearings are fixed for carrying
the bell cranks 1, and as the rods of the motors are proceeding outwards in.
making their forward stroke the adjustable tappet screws 2 come in contact
with the vertical levers of the bell crank, and the motion of the parts carrying:
the tappet screw being continued the bell cranks are rotated on their axes.
to a corresponding extent, the result of which is that the horizontal members
of the bell cranks are elevated, and at the same time the levers 3 are lifted,
causing the vertical movement upwards of the bars 4, which are fitted so
as to freely slide upwards and downwards in holes in the guide plates 5 and 6,
attached to the standard 7. The bars 4 are provided at about the centre of
their length with brackets 8, provided with adjustable tappet screws 9, as
more particularly seen at Figures 1 and 2, referring most to Figure 2, as
therein the motion for actuating the valves for regulating the currents through
the apparatus of hot and cold air is more easily understood than in the
other Figures. The motor contained in the casing A' is now moving
forwards, in doing which it has caused the elevation of the lever 3, the under
tappet screw 9 being thus brought to act upon and elevate the lever 10 by
the time the motor has approached to the end of its stroke, and also the
lever 11 which is rigidly secured to the lever 10 and movable about the samo
centre, so that this upward movement of the lever 11 causes its upper
extremity to be forced against a pin projecting laterally from the retaining
catch 12, which is pressed against the bar or rod 13, and a recess being
formed in the catch 12 in which the bar 18 fits, it follows that as long as the
spring 14 forces the catch against the rod 18 that the lever 16, and con-
sequently the valves attached to it by the liuks 17, are held in position, the

page_text: upward movement, however, of the lever 11, acting on the pin in the
retaining catch 12, forces it away from the rod 13, so that the framework
from which two of the valves are suspended, viz., one hot-air valve and one
cold-air valve, as shown at Figures 1 and 2, is free to rotate upon its axis,
the weights fixed to the levers 3 attached to the rods 4 cause the frame to
be thus partially rotated, or, in other words, have its position reversed, the
result of which is that the side 18 of the lever 19 is elevated, whilst its
other side is depressed by means of the weight of the valves and valve
spindles 17; the side or end 18 of the lever in its upward movement strikes
with a sharp blow on the point of a set screw in the extremity of the lever 20,
the lever 20 thus becoming slightly elevated, and therefore throwing back
the retaining catch 21, more particularly seen at Figure 1; this catch 21
being out of gear then leaves the frame 22, which being equipoised, and the
heat retainers 14 and 15 attached to it being also made of equal weights, a
perfect balance is obtained, so that a slight preponderating force applied to
one side will cause an alteration in the position of the framework 22 as well
as the beat retainers 14 and 15. This preponderating force may consist of
the weights shown on the lever 3, or instead of these a spring or compressed
air or any other suitable appliance may be used to depress the levers 3; the
heat retainer 14 being lowered to prevent the undue escape of heat from the
case A of the motor contained therein, to which heat is now applied, whilst
the heat retainer 15 is elevated to cause the surface of the case A¹ to be
freely exposed to the atmosphere, that the motor contained therein may be
cooled by the free exposure of the case A¹, as well as by the blast from the
fan being turned on into the case A¹, whilst the heat from the lamp is
turned off, the cooling proceeding at a corresponding rate to the heating of
the other motor, in order that the forward stroke of the motor being heated
may be performed to correspond with the back stroke of the motor being
cooled. At the instant of the overturning the frame 22 and its adjuncts,
both the cold-air valves are closed, and the frame 22 being now overbalanced
by the weights on the lever 3 causes the closing of the hot-air valves and
at the same time the opening of the valve attached to the rod 29.
As it is difficult to give a distinct description of the arrangement of the
valves themselves over and above what has been herein-before described, further
reference for a thorough comprehension of their action and arrangement is to
be made to the several Figures of the Drawings hereunto appended in
Sheets 1 and 2, in which the whole apparatus is delineated in such manner
as to be completely understood by the practical mechanic. Instead, however,
of adopting the means I have herein described for actuating the valves and

page_text: valve gear,
it may be arranged to be worked from one of the motors only,
and I wish it to be further understood that there are several other mechanical
arrangements besides that which I have herein set forth and shown in the
accompanying Drawings which may be adopted for that purpose. It may
be added that by a succession of the actions herein-before described and fully
set forth a continuous motive power may thus be obtained applicable for
actuating machinery on land as well as for actuating the propellers of ships.
The heat retainers 14 and 15 are made of felt or other material which is a
low conductor of heat.
Having now described the nature of my said Invention, and the manner
in which the same is or may be used or practically carried into effect, I
would observe in conclusion that I do not confine or restrict myself to the
precise details herein-before described and shown in the accompanying Sheets
of Drawings; but that what I consider novel and original, and therefore
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
First, the general arrangement and construction of machinery or apparatus
to be used for the obtainment of motive power, as herein-before described,
or any mere modification thereof.
Second, the application of the curvatures of compound bars when elevated
or lowered in temperature as a means or source for obtaining motive power,
as herein-before described, or any mere modification thereof.
In witness whereof, I, the said John Stuart Johnstone, have hereunto
set my hand and seal, this Twenty-second day of March, One
thousand eight hundred and sixty-seven.
TANK
JOHN STUART JOHNSTONE.
(L.S.)