IMPROVEMENTS IN HEATED AIR MOTORS APPLICABLE IN PART TO OTHER PURPOSES "
Year: 1883

page_text: LETTERS PATENT to Lewis Peter Martin of Vienna (Austria) Engineer and
Frederic William Gilles, of Cologne for an Invention of "IMPROVEMENTS IN
HEATED AIR MOTORS APPLICABLE IN PART TO OTHER PURPOSES
"
PROVISIONAL SPECIFICATION left by the said Lewis Peter Martin and
Frederic William Gilles at the Office of the Commissioners of Patents on the
20th June 1883.
LEWIS PETER MARTIN of Vienna Austria Engineer and FREDERIC WILLIAM
GILLES of Cologne " IMPROVEMENTS IN HEATED AIR MOTORS APPLICABLE IN
PART TO OTHER MOTORS [PURPOSES]"
Our Invention relates to improvements in the construction and arrangement of
heated air motors or hot air engines generally and in particular to a novel
arrangement of the working cylinder and air pump and the air passages, valves
and mechanism connected therewith as hereinafter described.
In hot air engines constructed according to our invention a vertical working
cylinder and an air pump are firmly supported upon a fire box mounted on a base
plate.
Between the cylinder and the pump a lever is mounted upon a horizontal axis
carried by an intermediate framing. The cylinder contains a piston packed with
cast iron rings and covered at its under side by a sheet iron drum or cylindrical
case which by loosening a nut on the cross head of the piston rod is capable of
being turned so as to expose all parts of its surface at cleaning doors when required
for the purpose of enabling it to be cleaned from the incrustation resulting from
contact with the impure gases.
One side of the piston is exposed for the purpose of being cooled and the main
piston is directly connected to the piston of the air pump by a rod which also acts
upon one extremity of the lever hereinbefore referred to by the intervention of a
jointed cross head arranged as follows:-
Between the extremities of the two beams composing the lever is provided a
frame or socket turning upon two studs. Through this frame is passed a bolt or
cross head capable of sliding freely therein; the piston rod passes through the

page_text: contre of this bolt or cross head and is secured thereto by a nut the sides of the
frame being cut away in a suitable manner to form a passage for the said rod.
By means of this arrangement the rectilinear movement of the rod of the pistons
in the working cylinder and air pump is not affected by the curvilinear movement
of the end of the lever tho effect of this latter movement being neutralised by the
combination of the longitudinal motion of the sliding bolt or cross head with the
oscillating motion of the extremities of the frame upon the studs. The piston rod
of the cylinder and pump is on the contrary guided in a straight path by means of
this arrangement. A rod jointed to the other extremity of the lever imparts rotary
motion to a driving shaft by means of a crank.
The inlet and outlet valves controlling the supply of air to the cylinder are
arranged horizontally and work in the cover of the air pump a suitable regulating
valve being fixed to the body of the pump.
The engine is provided with a governor worked in any suitable manner which
causes the excess of air to be conducted through outlet valves direct into the
atmosphere in place of taking it to the furnace whereby a superior adjustment of
the combustion is obtained.
The machine works expansively so as to obtain a reduction of pressure in the
cylinder at the end of a stroke and a silent discharge of air into the chimney. The
expansion motion of the inlet valve and the complete stroke of the outlet valve are
produced by a simple motion of the crank..
The passage for cold air leading from the air pump to the furnace and the hot air
passages leading from the furnace to the working cylinder and thence to the outlet
are so arranged as to form currents flowing in opposite directions.
The cold air from the pump passes along an external passage surrounding the
passage for the escape of hot air and circulates around and cools the valve chest
then continuing its course it undergoes a preliminary heating in hot chambers
underneath the fire grate. before being exposed to the full. heat of the furnace the
hot air passes from the furnace through an inlet valve to the working cylinder and
drives up the piston; when the latter reaches the end of its stroke the outlet
valve opens and discharges the hot air into the outlet passage leading to an
opening in the chimney provided with valves. In consequence of this arrangement
the current of cold air commences to be heated immediately on issuing from the
air pump by flowing in contact with the said outlet passage containing hot air
flowing in the opposite direction.
The distribution valves are arranged horizontally thus presenting the advantage
of the valves not being liable to stick or get burned on their seats or the valve rods
sticking or becoming overheated in their stuffing boxes or guides in consequence of
the lubricant flowing away this lubricant being rendered incapable of flowing away
from the rods so as to cause leakage at the valve seats.
The rods of the valves are supported at their two extremities at points outside
the valve chest so as to prevent leakage past the rods and valves. These
supports are so arranged that the valves and the rods on which they are carried
may partake of a rotary motion in addition to a reciprocating motion thus
equalising the wear.
This rotation of the valves and rods is obtained by means of suitable levers
which act excentrically upon the sides of pistons working in fixed guides anıl
keyed upon the extremities of the valve rods the valves being thus caused to
rotate to a small extent at each stroke.
The hot air passes along a passage leading from the furnace to the admission
valve and along another passage leading to the cylinder which is provided with an
outlet valve and a safety valve in direct communication with the chimney. The
niechanism for operating the inlet and outlet valves consists of an excentric acting
by the intervention of two rods upon levers operating two pistons connected by an
arm bearing against a coiled spring.
This mechanism operates in the following manner.
The rotation of the excentric
causes the rod for operating the inlet valve to press by the intervention of the

page_text: lever upon the piston on the corresponding valvo rod and open the inlet valve at
the same time the excentric action of this lever produces a rotary motion of the
valve. At the same time also that extremity of the arm herein before referred to
which corresponds to the rod of the inlet valve is moved and the spring extended
whilst the other extremity presses in the opposite direction upon the piston on the
rod of the outlet valve and presses the latter forcibly against its seat.
The excentric continuing to rotate the pressure upon the piston connected with the
inlet valve ceases and the piston is brought back to its initial position by the action
of the extended spring pulling on the arm. The inlet valve is thus closed whilst
at the same time the outlet valve is opened by the pressure of the levors on the
corresponding piston being at the same time caused to turn to a small extent and
the spring is again extended by the pull on the other end of the arm.
According to another arrangement balanced valves are employed in which the
cold air from the air pump before entering the furnace is utilised to cool and
produce a counter pressure upon the hot air valve, whilst the hot air flows in such
a manner as to tend to close this valve.
The valve chest is provided with an opening for the admission of hot air from
the furnace, au opening for conducting the air to the cylinder and an opening
leading to the chimney. A safety valve is provided between the furnace and the
chimney. The inlet valve is connected to a piston in a cylindor communicating
with the passage for cold air from the air pump. The cold air in this passago
presses upon this piston and thus balances the pressure of the hot air above or
below the inlet valve as required.
A similar piston fast upon the rod of the outlet valve works in a cylinder open
at the upper end and serves to balance the pressure on the outlet valve. Each of
the valve rods is provided with a protecting piston in front of the pistons employed
to balance the valves which also acts as a guide. The mechanisin of the distribution
is operated by a double excontric. The excentric rods act upon levers which
depress the valve rods by means of cams on rock shafts producing the motion in
one direction only according to the working of the ongine the motion in the
opposite direction being produced by means of springs.
The valve mechanisin may equally be employed for gas engineers and steam or
water motors as well as for hot air engines.
The furnace is composed of masonry enclosed in an iron casing encased in heat
retaining materials. All the doors as well as the hopper for the supply of fuel at
the upper part and fitted with double valves are capable of being hermetically
closed. Between the furnace and the discharge tube there is provided above the
valve chest a direct communication which enables the smoke or gaseous products of
combustion to pass directly from the furnace to the chimney when the engine is at
rest without passing through the other parts of the apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Lewis Peter Martin and Frederic William Gilles in the Great
Seal Patent Office on the 20th December 1883.
LEWIS PETER MARTIN of Vienna Austria Engineer and Frederic WilliamM
GILLES of Cologne "IMPROVEMENTS IN HEATED AIR MOTORS APPLICABLE IN
PART TO OTHER PURPOSES
"
Our said Invention relates to improvements in the construction and arrangement
of heated air motors or hot air engines generally and in particular to a novel
arrangement of the working cylinder and air pump and the air passages. valves
and mechanism connected therewith as hereinafter described
And in Order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheets of drawing the same letters of reference
indicating corresponding parts in all the corresponding figures
Figure 1 of the accompanying drawings is a vertical section of a heated air
engine or motor constructed according to our Invention
Figure 2 is a side elevation of the engine shewing the valve chest and passages
for hot and cold air in section
Figure 3 is a horizontal section taken along the line 1-2 Figure 1, and
figure 4 is also a horizontal section taken along the line 3- figure 2 or through
the valve chest
Figures 5 and 6 are details drawn to a larger scale showing the action of the
valves being respectively a longitudinal and a transverse section of the valve chest
Figure 7 is an elevation of the valve chest drawn to the same scale as figures 5
and 6
Figures 8. 9 and 10 represent a modified arrangement of the valves and figures
11. 12 and 13 are views drawn to a larger scale illustrating the construction of a
crosshead X hereinafter described
Figures 14 and 15 also drawn to a larger scale aro respectively sections of an
injecting pump and of a safety apparatus hereinafter described
C
In hot air engines constructed according to our Invention a vertical. working
cylinder B figures 1. 2. 3 and 4 and an air pump C are firmly supported upon a
fire box E mounted on a base plate A-Between the cylinder B and the pump
an oscillating beam or lever D is mounted upon a horizontal axis in bearings D¹
carried by an intermediate framing D²-The cylinder B contains a piston B¹
packed with cast iron rings and covered at its under side by a sheet iron drum or
cylindrical shield which by loosening a nut u on the crosshead X of the piston rod
is capable of being turned so as to expose all parts of its surface at suitable cleaning
doors L L' when required for the purpose of enabling it to be cleaned from the
incrustation resulting from contact with impure gases One end of the cylinder is
open for the purpose of cooling and working the piston B¹ which is directly con-
nected to a piston C working in the air pump C by a rod B which also acts upon
one extremity of the lever D by the intervention of a jointed cross head X the
construction of which is shewn more clearly in the detail figures 11. 12 and 13—
In these figures a a are two beams composing the lever D and c is a frame or
socket turning upon two bolts or studs bb in the extremity of the lever D
Through the frame is passed a bolt d forming part of the crosshead X and capable
of sliding freely in the said frame The piston rod B2 passes through the centre of
this bolt and is secured thereto by the nut u as shewn in the drawing-By means
of this arrangement the rectilinear movement of the piston rod B is not affected

page_text: by the curvilinear movement of the end of the lever D the effect of this latter
movement being neutralised by the bolt d sliding in the frame o which at the same
time oscillates upon the studs b The piston rod B² is on the contrary guided in a
straight path by means of this arrangement
A connecting rod G jointed to the other extremity of the lover D imparts rotary
motion to a driving shaft G¹ by means of a crank m-Suction and delivery valves
nn¹ figure 1 are arranged horizontally and work in the end of the air pump C, a
suitable automatic regulating valve V being fixed to the body of the pump for the
purpose of controlling the supply-The valve V is operated by a governor V1
worked in any suitable manner and which causes the excess of air to be conducted
through suitable outlet valves direct into the atmosphero in place of taking it to
the furnace whereby a superior adjustment of the combustion is obtained.
The engine works expansively so as to obtain a reduction of pressure in the
cylinder at the end of a stroke and a silent discharge of air into the chimney
The cold air proceeding from the air pump to the furnace and the hot air
proceeding from the furnace to the working cylinder and thence to the outlet are
caused to pass along separate passages marked respectively a' a' figure 2 and flow
in opposite directions as shewn by the arrows
The cold air delivered by the pump C passes along the annular external
passage al surrounding the passage a³ and circulates around and cools the valve
chest at Z then continuing its course it undergoes a preliminary heating in hot
chambers at e' underneath the fire grate or furnace E before being exposed to the
full heat of the said furnace-The hot air passes from the furnace E through an
inlet valve d to the working cylinder B and drives up the piston B' When the
latter reaches the end of its stroke an outlet valve e opens and discharges the hot
air into the outlet passage a surrounded by the passage el and leading to the
chimney. The advantage of this arrangement is that the current of cold air in
the passage a commences to be heated immediately on issuing from the air pump
by flowing in contact with the outlet passage a³ containing hot air flowing in the
opposite direction. The movements of the distribution valves & and e are so timed
as to produce the required degree of expansion in the working cylinder.
The axes of the distribution valves (figures 5, 6 and 7) are arranged horizontally,
thus presenting the advantage of the valves not being liable to stick or get burned.
on their seats or the valve rods sticking or becoming overheated in their stuffing
boxes or guides in consequence of the lubricant flowing away or gravitating to the
lowest point, the lubricant being rendered by this arrangement incapable of flowing
away from the rods so as to cause leakage. The disc shaped inlet valve d and
outlet valve e are contained in a case or valve chest Y and are worked by rods k
and -These rods slide horizontally in stuffing boxes r, s, and t, u, so arranged as
to prevent leakage, past the rods and valves.-These stuffing boxes or supports are
so arranged that the valves and the rods on which they are carried may partake of
a rotary motion in addition to a reciprocating motion, thus equalising the wear.
This rotation of the valves and rods is obtained by means of short lovers land m
which act excentrically upon the sides of pistons v, w, working in fixed guides, x, y,
and keyed upon the extremities of the valve rods.
The levers, m oscillate upon centres m³ and act upon the sides of the
pistons w, v, at points removed from the centres of the latter, as shewn more
clearly in Figure 7.-The effect of this arrangement is that the levers l, m, turning
on the centres l'm' tend to drag the pistons w, v, on one side in such a manner as
to cause the said pistons to turn to a limited extent upon their axes at each
oscillation of the levers and thus impart an intermittent rotary motion to the
valves at every oscillation of the levers l, m.
The said levers controlling the valves e and d, are operated by an excentric.
pin h, acting by the intervention of two rods n, and o, upon the levers l, m, which
impart a combined reciprocating and rotary motion to the valve rods and valves as
herein before described. The valves d, and e, are closed by the action of a spring q,
connected to the valvo rods by a jointed lever p, as shewn in figure.5. -
-
"N

page_text: The valve inechanism operates in the following manner. The rotation of the
excentric pin h. 'in the direction of the arrow (Figure 5) causes the rod n, to press
by the intervention of the lever upon the piston wo on the valve rod k, and open
the inlet valve d, at the same time the excentric action of the lever L, produces a
rotary motion of the piston w. The jointed lever or arm p, hereinbefore referred
to is caused to oscillate and acts upon the valve rod i, with a force corresponding
to the tension of the spring 9 in such a manner as to press the outlet valve e
forcibly against its seat.
Heated-air-under-pressure-entering_the_valve chest through an opening c
communicating with the hot air passage then passes the valvo d, and proceeds-
through an opening f, to the working cylinder B.-The pressure of this air on the
piston B drives up the latter and the shaft G¹ describes half a revolution. The
inlet valve d, is now closed by the action of the spring q, the said valve being
arranged to close at any desired part of the stroke. During the next half
revolution of the crank shaft that is to say during the descent or return stroke of
the piston B¹ the lever m acts upon the piston v, and opens the outlet valve e, at
the same time causing it to turn upon its axis as herein before described. The
contents of the working cylinder now exhaust past the valve e, and pass through
an opening into the chinney. During the exhaust the inlet valve d, is pressed
firmly against its seat by the pressure of the air and the action of the spring q.
The crank shaft having thus completed one revolution the action of the excentric
again reverses the relative positions of the inlet and outlet valves and air under
pressure is again admitted to the working cylinder as herein before described. The
valve chest is provided with a Safety valve d' communicating with the chimney.
The valve mechanism is so arranged as to cause the air to act expansively in the
working Cylinder, the inlet valve d. being closed before the stroke is completed.
Figure 8 is a transverse Section, Figure 9 a longitudinal Section and figure 10 n
plan of a Valve chest in which balanced valves are employed.-The air from the
air pump before entering. the furnace is utilised to cool and produce a counter
pressure upon the inlet valve and tends to balance the pressure of the hot air.
The Valve chest Y is provided with an opening a for the admission of hot air
from the furnace, an opening b for conducting this air to the working cylinder B
and an opening e leading to the chimney. A safety valve d' is also provided
between the furnace and the chimney. The inlet valve d is connected by a valve
rod n, to a piston w, working in a cylinder k, situated in a chamber g. and the
outlet valve e, is similarly connected to a piston m, working in a cylinder . Air
from the air pump is supplied through a pipe h. (Figures 8 and 9,) to the chamber g,
in which it circulates round the cylinder and then proceeds to the furnace
through a passage i.
The cold air in the chamber g is thus caused to press upon the piston k, for the
purpose of neutralising the effect of the pressure of the hot air on the valve d.
The piston m fast upon the rod v works in a similar manner in the cylinder 1,
open to the atmosphere at the upper end and thus serves to balance the pressure
on the valve e. Each of the valve rods v, and w, is provided with a protecting
piston or shield z, which also acts as a guide. The mechanism of the distribution is
operated by a crank n' and an excentric n' by the intervention of connecting
rods o and p which transmit a reciprocating motion to levers q and r. Those
levers are connected to sleeves st rocking on a shaft x and provided with cams 8¹
and which act upon arms a³t on the valve rods n and v producing a positivo
motion in one direction only according to the working of the engine the motion
in the opposite direction being produced by means of springs x and y the action
being analogous to that of the mechanism herein before described with reference to
Figures 5, 6 and 7.
This valve mechanism may be employed for gas engines and steam or water
motors as well as for hot air engines.
The furnace E is composed of masonry enclosed in an iron casing preferably

page_text: horeinafter described are capable of being hermetically closed. This furnace is
supplied with fuel by means of a feeding hopper K arranged above the furnace
and provided with openings at its upper and lower part capable of being closed
by valves K. Between the furnace and the discharge tube there is provided
above the valvo chest a direct communication e' which enables the smoke or
gaseous products of combustion to pass directly from the furnace to the chimney
when the engine is at rest without passing through the other parts of the
apparatus.
In some cases it is advantageous to inject oils or gases at elevated temperatures
into the furnace as hereinafter described. For this purpose a plunger or forco
pump is employed worked by an excentric on the horizontal shaft G' (fig 5) This
pump is shown drawn to a larger scale in Figure 14. a is the suction pipe
supplying the pump with petroleum or other liquid from a suitable reservoir→
b is the cylinder of the pump and f' is a delivery pipe leading to the furnace.
Inside the delivery pipe f1 there is provided a safety apparatus O for the
purpose of proventing the accidental ignition and explosions of the liquid or gas
which would otherwise be liable to be produced by the heat.
This safety apparatus is illustrated in longitudinal and transverse section in
figure 15 and consists of a pipe or cylinder C₁ of larger diameter than the pipe f¹
and in which are packed a number of slender rods or wires c¹ presenting a number
of narrow triangular passages c³ in their interstices. Theso rods do not obstruct
the passage of the gases or oils but by the length and contraction of the
channels the gases are effectually cooled and explosions are prevented from
being transmitted to the other side of the safety apparatus C. d³ is a check valve
through which the liquids or gases enter the furnace where they are mixed with
the products of combustion.
The supply or introduction of liquids may be regulated by means of a valvo
or cock worked either by hand or by a governor and which contracts or closes
the passage fas the speed increases and causes the liquid to return to the
reservoir through a suitable branch pipe.
Having now described and particularly ascertained the nature of our said
Invention and the manner in which the same is or may be used or carried into
effect we would observe in conclusion that what we consider to be novel and
original and therefore claim as the Invention secured to us by the hereiubefore in
part recited Letters Patent is :-
First: The general construction and combination of parts constituting the
improvements in heated air motors substantially as hercinbefore described and
illustrated in the accompanying drawings.
Second-In heated air or other like motors the employment for controlling the
inlet and outlet passages cominunicating with the working cylinder of disc valves
acting horizontally and partaking of an intermittent rotary motion in combination
with the mechanism for operating the said valves substantially as hereinbefore
described and illustrated in Figures 5, 6 and 7 of the accompanying Drawings.
Third: In heated air and other like motors the employment for the purpose of
operating the distribution valves of two connecting rods whereby the opening
and closing of the said valves is effected by the direct action of the crank shaft
at the proper intervals so as to enable the air to act expansively in the working
cylinder substantially as hereinbefore described and illustrated in figures 8, 9
and 10 of the accompanying drawings.
Fourth-The employment in heated air and other like motors of disc valves
so balanced and operated as to cause the air to flow alternately to and from the
working cylinder along passages constructed and arranged substantially as
hereinbefore described and illustrated in Figures 2, 5, 6, 7, 8, 9 and 10 of tho
accompanying Drawings.
Fifth In heated air and other like motors transmitting motion from the
reciprocating piston rod to an oscillating beam or lever by means of a cross-head

page_text: provided with a bolt & rigidly attached to the piston rod and sliding in a framo c
jointed to the end of the said lever substantially as hereinbefore described and
illustrated in Figures 11, 12 and 13 of the accompanying Drawings.
In witness whereof I the said Lewis Peter Martin on behalf of the said Frederic
William Gilles and myself have to this our Specification set my hand and seal
this eighteenth day of December One thousand eight hundred and eighty three.
[sic] LOWIS PETER MARTIN (Ls.)
•