Improvements in Compressed Air, Carbonic Acid, and like Motors
Year: 1897

page_text: PROVISIONAL BERUIFICATION.
Improvements in Compressed Air, Carbonic Acid, and like Motors
We, EDOUARD MOLAS, Mechanical Engineer, and EUGENE LAMIELLE, Art Iron
Worker, both of 45, Rue du Chemin-Vert, Paris, in the Republic of France, do
hereby declare the nature of this invention to be as follows:-
:-
Our invention relates to a novel system of distribution for compressed air and
carbonic acid motors in which four single acting cylinders are combined, coupled
together in pairs at 180° to one another, the two groups being themselves placed
at 90° to each other.
The distribution for each cylinder is effected by means of a pair of valves work-
ing together, one for the admission and the other for the exhaust; it is obvious
that the seats of the united valves are suitably arranged in order that their
simultaneous movement shall cause the opening of one and closing of the other.
Each of the pistons located in the twin cylinders thus becomes active during a
half revolution of the motor shaft; the second pair of pistons working at an angle
of 90° to the first, dead points are avoided and great case of movement is obtained.
The valves are operated by a beam, the axis of oscillation of which is placed
between the two pairs of valves so that one moves outwards while the other moves
in the opposite direction.
The beam for operating the valves is driven by a guide rod jointed to a slide
moving in a guide jointed at its upper part to a fixed point; the position of this
slide in the guide allows of varying the duration of admission into the cylinder
between very wide limits, according to whether the slide is brought nearer to or
farther from the fixed point at which the guide is jointed, and which for this reason
we term the "expansion guide."
Movement is imparted to this expansion guide by a bar jointed thereto, the other
end being jointed to a slide adapted to move in a second guide designed to effect a
reversal of the motion. In fact this guide can be moved so as to operate the expan-
sion guide through the medium of one or the other of two cams joined together
and keyed upon the motor shaft, the said cams being alike in shape but arranged
symmetrically with relation to one another.
Each of these cams operates a carriage of special construction hereinafter described,
these carriages being jointed respectively to the two ends of the "reversing
guide."
The direction of motion of the motor as well as the expansion can thus be varied
as required.
The cams are keyed upon the motor shaft and by means of the carriages provided
with rollers, drive a sector or reversing guide suspended by means of a short
pendent rod from a crank. In the slot of this guide is held, by means of a brass
slide, the forked head of a rod transmitting the motion to another guide called the
distribution or expansion guide suspended from a fixed point. In the slot of the
latter guide slides, according to the inclination of the operating lever on a sector, a
distribution rod suspended by means of a pendent bar from another crank.

page_text: This distribution rod, operated by the lever, communicates a varying alternating
movement to the beam by means of a cylindrical rod working through a guide
provided for this purpose, the junction of the beam and the said rod being effected
by means of a joint. The beam is connected to a series of small suspension rods
by pivots keyed like those of the small slides through the apertures of which pass
the inlet and exhaust valve rods.
The cylinders are in pairs and integral with one another, each pair serving the
purpose of a double acting cylinder the two connecting rods of which actuate two
cranks on the main shaft, arranged at an angle of 180°, the other pair is mounted in
the same manner but at an angle of 90° in relation to the former. The ends of a
pair of cylinders are made in one piece in which are the chambers and ports of the
inlet and exhaust valves. The four valves are arranged in this piece in the same
line passing through the axes of the two cylinders and perpendicularly to their
generatrices. This piece is fixed to the flange of the cylinders by means of bolts
and nuts. On this piece is fixed a bracket in the form of a bridge designed to
afford a bearing surface for spiral springs which actuate the valves as well as to
ensure their perfect rectilinear movement, and moreover to bear the point of support
and oscillation of the beam.
In each cylinder the exhaust valve closing upon a leather washer opens towards
the interior of the cylinders and is provided with a shoulder allowing the pivoted
slide operated by the beam to open it even when under pressure. The closing of
the same is effected by contact with a second shoulder formed by a nut fixed on its
rod; a spiral spring is placed between this shoulder and the slide operated by the
beam; moreover the pressure as soon as it is established in the cylinder continues
to force it to its seat with a higher degree of energy in proportion as the pressure
increases. A second spiral spring, weaker than the preceding one and incapable
of forcing back the valve bears upon the bracket which serves as a guide for the
valves and upon the other shoulder formed by the nut and tends to keep the valve
constantly open.
This arrangement has for object to permit a very reduced admission and to work
absolutely without admission when working with a vacuum, utilizing the acquired
speed, the exhaust valve thus opening, as soon as the interior pressure is less than
the combined power of the spring and atmospheric pressure.
The inlet valve consists of a pointed steel rod closing an opening of less
diameter than that of the base of the cone which constitutes the point. It is kept
to its seat by a very strong spiral spring having its bearing upon the bracket and
acting upon a shoulder on the pointed rod the other face of which is opposite the
pivoted slide. The automatic closing is thus ensured and its opening is effected
by the slide coming in contact with the said face of its shoulder.
The axis of the beam being placed between the two groups of valves it follows
that the oscillation of one arm lifts the two valves of the same cylinder, and con-
sequently closing the oxhaust valve and opening the inlet valve, at the same time
that the other end of the beam, which is placed in a reverse position with regard
to the former, forces the exhaust valve of the other cylinder to open in cases where
the pressure would still keep it applied to its seat and the resistance of the spring,
arranged to open it, would still have to be overcome.
In this manner no counter pressure can be.produced during the return of the
piston.
The advance at the exhaust and admission is effected by means of the
cams the peculiar form of which divides the working of the valves into two
phases.
The first phase effects the closing of the exhaust of one cylinder the piston of
which returns towards the end and arrives at 95/100 of its stroke, the air
confined thus forming a deadening cushion at the moment of inertia.
At the same time as this closing is brought about the other end of the beam
forces the exhaust valve of the other twin cylinder to open thus allowing fluid
under pressure to egress before the commencement of the return stroke of the

page_text: piston. This valve is moreover kept open during the 95/100 of the return
stroke of the piston, allowing the fluid contained in the chamber of the
cylinder to flow freely up to the moment of the closing hereinbefore
described.
The second phase effects the opening of the inlet valve of the last named
cylinder for the entrance of the motive fluid, whilst the other end of the beam
increases and brings to its maximum the opening of the exhaust valve of the said
cylinder.
The closing of the inlet valves is gradually effected by reason of the
curves of the cams which slowly bring them on to their seats where they are
held in place by the powerful pressure of the strong spiral spring provided for
that purpose.
I would observe that during this second period the continued movement of the
beam operating the valves is (as far as regards the exhaust valve of the first
named cylinder which upon reaching its seat cannot rise) received by the spring
which still more forcibly applies the exhaust valve to its seat just at the precise
moment when the admission begins.
With regard to the inlet valve of the other cylinder the slide not encountering
anything in its course does not in any way alter the position of the said valve, as it
is held firmly to its seat by a strong spiral spring.
The reverse operation, that is to say, the admission to the second cylinder and
the exhaust from the first cylinder is effected under similar conditions, the beam
being in reverse positions froin those previously occupied.
The advance at the exhaust and admission is therefore effected by these arrange-
ments and the moment of inertia produced by the change of movement is therefore
partialy overcome.
The expansion, which is variable as required, is obtained by the position of the
head of the distribution rod the axis of which describes an arc of a circle which
is so much the larger, the lower it is moved down in the guide. This arrangement
allows of the stoppage of the admission by raising the head of the rod to near the
point of oscillation of the guide so as to obtain a very small movement of the
beam, whereby it is prevented from lifting an inlet valve while allowing free
action, in the direction of the aperture, to the exhaust valves which can thus work
automatically under the action of the atmospheric pressure, but compels them con-
stantly to open, should they be closed by the rapid back stroke of the piston upon
the fluid admitted into the interior of the cylinder during the suction.
This arrangement has for object to allow a carriage or a boat provided with this
motor to travel forward under the acquired impulse, after the stoppage of the
admission, without any danger to the motor.
It is obvious that a more or less pronounced inclination of the operating lever in its
graduated sector will cause a larger or smaller admission which may vary from 0 to 80%
for traction and step gradients. Expansion can therefore take place during about
of the total stroke.
to
For the reverse motion of the engine the arrangements are the same except as
regards the camns keyed on the shaft, and which are placed in the reverse position;
a second roller carriage transmits the varied alternating movement of the back
action cam to the other end of the reversing guide which is raised by means of the
suspension guide and the crank upon the driving shaft of the operating lever. The
carriages are each provided with two rollers between which the corresponding cam
is always located in order to allow each carriage to be brought smoothly backwards
as well as forwards; one of these rollers is fixed; the other bears with its pivots
upon a bearing on which presses a spring; a screw the point of which passes
through the spring limits the extent of travel of the axis of the roller in case of irregu-
larities in the contour of the cam. We would observe that the contour of the cams
is such that the diameters of the cams are all equal, so that the rollers are always in
contact with their respective cams.

page_text: The herein before described rod the head of which is provided with a slide, is
operated by its guide and is kept in a nearly rectilinear course, thereby ensuring
the concordance of its axis with those of the suspension pivots of the guide, by
a hanging bar oscillating upon a fixed point. The other end of this rod
communicates its movement to the distribution guide oscillating upon a fixed
point.
Arrangements have been adopted for ensuring the tightness of the valves and for
regulating the tension of the springs; the herein before described bracket is provided
with four small screw-threaded brass bushes or sockets serving both as guides for the
rear ends of the valve rods and as a bearing for the springs, one of which is designed
for opening the exhaust valve and the other for keeping the admission valve closed;
they are regulated by screwing or unscrewing the said bushes.
The advantages to be derived from this motor are the following:-
Operation in both directions without transmission or gearing; admission comprised
between zero and 80% of the total stroke of the piston; expansion variable as
required at any moment and with the aid of a single lever; complete stoppage of
the admission at any moment, without danger to the machine and without producing
negative power, by means of the same lever, the inclination or setting upright of
which gives the required admission or completely stops it; the possibility when
being used for traction upon an incline of employing a larger admission with a
greater pressure, in fact an elasticity indispensable for motors designed for use
with motor cars or the like; an automatic expansion adjustable as required and an
automatic petroleum heater allowing the employment of dry compressed air at
a very high pressure thus reducing to a minimum the capacity to be given to the
feeding reservoirs; the relatively small weight (about 160 kgs.) of the motor, for
a power which can be raised to twenty HHP. renders it particularly adapted for use
with motor cars and the like as great facility is afforded for reducing the power
of the motor to zero.
Moreover its compactness and the assembling together of all its members upon
the same engine obviate the employment of the transmissions and gearing hitherto
generally employed.
We almost completely do away with detrimental spaces by the arrangement of
the valves.
The relatively low cost of feed and facility of access of all the important
parts is another of the advantages to be obtained by the employment of this
motor.
Dated the 6th day of Narambar 1807
COMPLETE SPECIFICATION.
Improvements in Compressed Air, Carbonic Acid, and like Motors.
We, EDOUARD MOLAS, Mechanical Engineer, and EUGÈNE LAMIELLE, Art Metal
Worker, both of Paris, France, do hereby declare the nature of this invention, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
This invention relates to a novel system of distributing gear for engines operated
by compressed air or carbonic acid gas in which are combined four single acting
cylinders coupled together two and two at 180 degrees to each other, the two
groups being themselves placed at 90 degrees to each other. The distribution is

page_text: 'T'he
effected for each cylinder by a pair of valves working together, the one for the
admission and the other for the exhaust, it being understood that the seats for
these valves are suitably arranged so that a simultaneous movement shall produce
the opening of the one and closing of the other valve. Each of the pistons working
in the twin cylinders thus becomes operative during half a revolution of the
driving shaft and as the second pair of pistons work at 90 degrees to the former,
dead points are avoided and great smoothness of running is obtained.
movement of the valves is controlled by a lever having its axis of oscillation
placed between the two pairs of valves so that whilst the one pair move in one
direction the other pair move in the reverse direction. The lever which controls
the valves is operated by a rod jointed to a slide block which slides in a quadrant
pivoted at its upper end on a fixed point, the position of the slide block in the
quadrant being alterable so as to permit of varying the period of admission to the
cylinders between very wide limits, according as the slide block is more or less
distant from the fixed point of articulation of the quadrant which for this reason
we denominate the expansion quadrant. The expansion quadrant is itself
operated by a jointed bar, whose opposite end is jointed to a slide block capable of
adjustment in a second quadrant which serves for reversing the engine, and which
is capable of being shifted for the purpose of operating the expansion quadrant by
the one or the other of two cams of similar profile keyed together upon the
driving shaft, but disposed symmetrically the one to the other and each acting
upon a cam bar of special construction hereinafter described, the said cam bars
being respectively jointed to opposite ends of the reversing quadrant. By the
means above described, both the direction of motion of the engine, and also the
degree of expansion, can be regulated at will.
The invention is illustrated in the accompanying drawings which represent a
compressed air engine provided with our improved system of distributing gear.
Figure 1 is a side elevation and Figure 2 a half plan of the mechanism, partly in
section. Figure 3 is a sectional side elevation shewing the arrangement of the
cam bars of the reversing link one of the cylinders being shewn in section.
Figure 4 is a cross section of a pair of cylinders. Figure 5 is a cross section of
the rear end or cover of the cylinders, shewing the admission and exhaust orifices
for the compressed air or fluid. Figure 9 is a rear elevation of the cylinders,
shewing the mechanism for operating the valves. Figures 6, 7, and 8 shew details
of the reversing link. Figure 10 shews, on a larger scale, the pair of cams-for
operating the cam bars which control the reversing quadrant.
i
The cams A A¹ are keyed on the driving shaft R and control with the aid of the
slotted cam bars Z Z¹ (which are provided with friction rollers) a reversing.
quadrant B which is hung by a pair of links C from a crank arm X.
In the slot
of quadrant B works a slide block carried by the forked head of a rod F which
transmits motion to a second so-called distributing or expansion quadrant G.
suspended from a fixed point I in which quadrant G slides (according to the degree
of inclination of a hand lever-not shewn-moving over a quadrant) a distributing
connection rod K which is hung by means of suspension links H from the crank
arm J. The connecting rod K which is controlled by lever F imparts a variable
reciprocating motion to a rocking beam Q through a cylindrical rod L sliding in a
guide, and coupled to said beam by a crosshead and link connection. To the
rocking beam Q is coupled (by means of pivot pins) a series of small connecting
rods q, q', 92, 93, and also the small slide blocks V through which the admission
valve rods P, P₁, and exhaust valve rods O, 0¹, pass. The cylinders D, D¹, are
cast in one each pair fulfilling the purpose of one double acting cylinder, the two
connecting rods E, E¹, respectively actuating two cranks upon the crank shaft R,
placed at 180 degrees to each other. The other pair of cylinders is exactly similar,
but placed at an angle of 90 degrees to the first pair. The corners of the two
cylinders of each pair are formed as a single casting N in which are the chambers
and apertures of the admission and exhaust valves, these four valves being arranged
in the plane of the axes of the two working cylinders, and the axes of the valves

page_text: being parallel to the axes of the cylinders. The cylinder cover is bolted to the
flange of the cylinders and upon it is fixed a bridge piece U adapted to serve as an
abutment for helical springs which act on the valves, as well as to ensure perfect
rectilinear movement of the latter, and also serving to carry the fulcrum for the
rocking beam Q. The exhaust valve ( of each cylinder is in the form of a clack-
valve closing against a leather washer and opening inwards into the cylinder, and
it is provided with a shoulder to permit of it being opened by the slide-block V
under the action of beam Q even against pressure within the cylinder. The closing
of the valve is effected by the slide block V (when moving in the opposite
direction) engaging a second shoulder formed by a nut a upon the valve stem b,
a helical spring c being interposed between the nut a and the slide block V; whilst
immediately pressure is established in the cylinder the valve is held upon its seat
with a force proportionate to such pressure. d is a second (and weaker) coiled
spring bearing at the one end against the bridge piece U and at the other end
upon nut a so as to tend to hold the valve constantly open. This arrangement has
for object to permit of a very slight admission on the one hand and of working
absolutely without admission ou the other; when thus working by utilizing the
momentum acquired, the exhaust valve opens immediately pressure within the
cylinder is inferior to the combined effects of the springs and of atmospheric
pressure. The admission valve P consists of a steel pin closing an orifice of smaller
diameter than that of the base of the cone forming the end of the pin. The valve P
is held constantly to its seat by a strong helical spring e abutting against the
bridge U and acting upon a shoulder f formed on the valve stem, the block V
sliding upon the stem between the shoulder f and the valve seat. The valve is
thus closed automatically and opened by the slide block V coming in contact with
the shoulder f. The fulcrum of the rocking beam Q being between the two groups
of valves, as shewn, it follows that the oscillation of one arm of the beam actuates
the stems of both valves of the same cylinder, in such a way as to close the exhaust
valve O and open the admission valve P, at same time that the other arm of the
beam Qoscillating in the opposite direction, forces open the exhaust valve of the
other cylinder even in the case where the pressure within the cylinder would still
hold it down upon its seat, notwithstanding the resistance of the spring which tends
to open it. It will thus be evident that no back pressure can be produced during
the return stroke of the piston.
The initial period of exhaust and admission is obtained by the cams A A' which
are made of a form suited for dividing the working of the valves into two phases
which may be followed on the drawing. The first phase determines the closing of
the exhaust S¹ of cylinder D¹ whose piston (see Figure 2) is now making its return
stroke and has accomplished 95 per cent. thereof, counting from the dead point, the
imprisoned air thus forming a cushion. At same time that S¹ is closed, the other
extremity of beam Q obliges the exhaust valve S of the twin cylinder D to open,
thus permitting the fluid under pressure in that cylinder to escape before the
commencement of the return stroke of the piston. The valve S remains open during
95 per cent. of the return stroke of the piston, permitting the fluid within the
cylinder to be freely expelled until the moment of closure as above described. The s
second phase determines the opening of the valve P of cylinder D for the admission
of the motive fluid, whilst the other extremity of the beam Q still further assists
this movement, by opening the exhaust valve S₁ of cylinder D¹ to the full extent.
The opening of the admission valves is gradually effected by reason of the curvature
of the cam, as is also their closure on their seats where they are retained in place
by the pressure of the strong spring e. It will be remarked that, during this second
phase, the continuation of the movement of the rocking beam Q is sustained (as
regards the exhaust valve 0¹ of cylinder D¹ which, being in contact with its seat,
cannot more further) by the spring which thus presses the exhaust value still more
strongly upon its seat just at the precise moment when the admission commences. 6
As regards the admission valve P of cylinder D, inasmuch as the slide block meets
with no impediment to its progress, it does not in any way change the position of

page_text: said valve, which is held firmly in its seat by a strong coiled spring. The reverse
operation, that is to say the admission to cylinder D and the exhaust from cylinder
D is effected under the same conditions, the rocking beam Q then moving in the
reverse direction.
The initial period of the exhaust and of the admission thus takes place under the
above conditions, and the dead point produced by the change of movement is thus
in part obviated. The expansion, variable at will, is obtained by the position of the
head of the connecting rod K which describes an arc of a circle whose radius is the
greater the lower the head of rod K descends in the quadrant G. This arrangement
permits of cutting off the admission by raising the head of the connecting rod nearly
up to the point of oscillation I of the quadrant so as to produce so slight a move-
ment of beam Q as to be insufficient to open either of the admission valves; at same
time allowing full liberty (in the direction of opening) to the exhaust valves 0, 0¹
which may thus act automatically under the effect of atmospheric pressure but
constantly forcing them to open, notwithstanding they may have been closed by the
rapid backward action of the piston upon the fluid entering the cylinder during the
suction. This arrangement has for object to enable a vehicle or vessel provided
with the improved engine to move forward after closing the admission, under the
momentum acquired, without in any way damaging the engine. It will be evident
that by placing the starting lever in a more or less inclined position upon its
graduated quadrant, an admission varying from 0 to 80 per cent. may be obtained
for starting and for steep inclines, the cut off may therefore take place at from
one-fifth to nine-tenths of the total stroke.
For backward motion the arrangements remain the same except as regards
transmission of motion from the cams A A¹. These are reversely placed with
regard to each other and a second cam bar Z transmits a variable reciprocating
motion from the backward motion cam to the other end of the reversing quadrant B
which is raised by means of the suspension link C and crank X keyed on the shaft
of the starting lever. The cam bars Z Z are each provided with two rollers
between which the corresponding cam is constantly maintained so as to cause each
cam bar to work smoothly in either direction. One of these rollers h turns on a
fixed pivot while the pivot of the other roller i is fitted to slide in a slotted bearing m
and is kept in engagement with the cam by a spring n, which is capable of adjust-
ment by means of a screw p for the purpose of regulating the position of roller i to
follow the irregularities in the contours of the cams A A¹, (which are exactly equal
in diameter) so that the rollers h and i are always in contact with their respective
The movement of that end of rod F which engages in the quadrant B is
maintained as nearly as possible rectilinear (so as to ensure proper alignment of its
centre line) by means of the suspension link T oscillating about a fixed point t.
The other extremity of rod F communicates motion to the distributing slide link G
which oscillates about a fixed point 1. Suitable provision is made for ensuring the
fluid tightness of the valves and for regulating the tension of the springs the bridge
piece U being provided with four small screw-threaded brass bushes, serving both
as guides for the ends of the valve spindles and as adjustable abutments for the
springs, the adjustment of the springs being effected by screwing the bushes in or
cains.
out.
:-
The advantages possessed by the improved motor may be thus summarized
The production of forward or backward movement without transmitting or toothed
gear the capability of varying the admission between zero and 80 per cent. of the
whole stroke of the piston; the capability of varying the ratio of expansion at any
moment by the movement of a single lever; the possibility of completely closing
the admission at any moment by means of the same lever without danger to the
engine and without producing negative strains; the possibility of employing a
fuller admission and a higher pressure when starting or on an incline; in short, a
handiness and controllability which is especially required in motors used for road
travelling. Further advantages consist in the provision of an automatic expansion
device capable of being regulated at will and an automatic petroleum heater

page_text: permitting of the employment of dry air compressed to a very high pressure, thus
reducing to a minimum the volume of the feed reservoirs. The comparatively small
weight of the motor (about 160 kilogrammes for one working up to 20 horse power)
renders it eminently suitable for use on motor vehicles, in view of the great facility
it affords for reducing the power to zero. Moreover owing to its compactness, and
the mounting of all the mechanism upon the engine itself, the employment of
transmitting and toothed gear hitherto generally employed, is avoided. By
arranging the valves in the manner herein described, clearance spaces are almost
entirely avoided. The relatively low consumption of motive fluid and the facility
of access to all the principal parts are also further advantages characterizing the
motor.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1st. The herein described improvements in compressed air, carbonic acid, and
other motors substantially as described and illustrated in the accompanying
drawings.
2nd. In an engine worked by compressed air or other fluid the herein described
system of distributing valve gear comprising the following essential features, viz. :-
(a) The coupling of the admission and exhaust valves in pairs, each pair serving
one cylinder, and one movement of the operating lever simultaneously producing
opposite effects in the two pairs, and in the members of each pair;
(b) The springs and abutments for ensuring the independence of the exhaust
valves when the engine is running without motive fluid, the valves opening of
themselves under the atmospheric pressure, when the admission is cut off ;
(c) The expansion device for allowing of variable admission while the engine is
running;
(d) The reversing mechanism consisting of cam bars actuated by cams and jointed
at opposite ends to a quadrant which may be shifted with regard to a slide-block
which operates the expansion quadrant through a connecting rod, the said cams
being arranged with regard to each other as described and the reversing quadrant
being actuated by the one or other cam bar according to the position of the
quadrant ;
(e) Arranging the valves as close as possible to the rear ends of the cylinders as
to avoid clearance spaces as far as possible;
(f) The general arrangement and combination of parts whereby the engine is
rendered very readily controllable.
Dated this 3rd day of September 1898.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, Londou.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.