AN IMPROVED ROTARY MOTIVE-POWER ENGINE
Year: 1877

page_text: LETTERS PATENT to Joseph Ravel, of Paris, Boulevard de Strasbourg, No. 59,
Engineer, for the Invention of "AN IMPROVED ROTARY MOTIVE-POWER
ENGINE."
Sealed the 9th April 1878, and dated the 12th October 1877.
PROVISIONAL SPECIFICATION left by the said Joseph Ravel at the Office of
the Commissioners of Patents on the 12th October 1877.
JOSEPH RAVEL, of Paris, Boulevard de Strasbourg, No. 59, Engineer. "AN
IMPROVED ROTARY MOTIVE-POWER ENGINE."
The object of this rotary machine consists in the displacement of a piston-forming
weight, which acts alternately by its weight at the extremities of a cylinder, upon
the centre of the length of which the trunnions of. the axis of rotation are fitted.
The displacement of the piston in the cylinder takes place when the cylinder is
vertical, and when the piston is at the lower part of the said cylinder by the
expansive force of a detonating mixture, or by compressed air, by steam, or by any
other fluid. I suppose this cylinder, animated with its movement of rotation upon
its trunnions, the cylinder has arrived at a vertical position, and the piston is at the
bottom by the force of explosion; this latter is driven to the upper part of the
cylinder; this piston-forming weight draws the cylinder with it, and continues
the movement of rotation. When the machine has effected a half revolution the
cylinder has again become vertical, but it is turned over. The piston is still at the
lower part, a new explosion will cause it to re-ascend, and the movement will
continue thus indefinitely.
If there are coupled side by side, and perpendicularly one to the other, two similar
cylinders, each enclosing a piston-forming weight, and both mounted upon the same
trunnions, a continuous movement of rotation of great regularity will be realised.
Such is the principle of my rotary machine with a variable centre of gravity.

page_text: The cylinders are placed perpendicularly, carried by two trunnions, which turn in
the plummer blocks of two supports. One of the trunnions is pierced with four
horizontal conduits, one for the arrival of gas, one for the arrival of refrigerating
water in circulation between the cylinder and the casing, another as an exit of the
water which has become heated by circulation, and another for the escape of gases
and the products of explosion. These four conduits, which serve for the two cylinders,
communicate by means of tubes with their respective ports or orifices. The same
trunnion carries a boss or enlargement, which engages by slight friction in a dis-
tributing box, in which are formed three circular necks or hollows, and a central
opening, the necks corresponding to the first three conduits, and the central opening
to the escapement conduit.
A piston which forms a weight is moveable in the cylinder; it abuts against a
regulating screw, a space serving to contain a detonating mixture.
A rod fastened to a spring deadens the shock of the piston against the bottoms of
the cylinder; by means of two screws the advance of this rod is regulated and the
space reduced accordingly.
The gas arrives by a tube furnished with a cock to regulate it, which comes out
into a circular neck of the distributing box; the gas passes through the corre
sponding conduit, and from there passes by means of tubes into the slide valve and
to the burners for firing.
A pump presses upon the cold water in a pipe, which comes out in the same
manner into a second circular neck; a corresponding conduit and the tubes lead
this refrigerating water to the bottom of the cylinders into a space. The heated air
comes out again by the third conduit of the trunnion.
Each of the valves is composed of a moveable plate commanded by the cam (a cam
for each cylinder). This cam is fixed upon the trunnion, and the rods of the valves,
constantly solicited by springs, press upon this cam.
The moveable plate is maintained against a face of the cylinder by a counterplate
fixed in a frame.
The valve has a cavity destined to put in communication the arrival orifice of the
detonating mixture with the interior of the cylinder by a port. A conduit com-
municates on one side with the atmosphere, and on the other with a port which
debouches into a conduit of the detonating mixture. The gas arrives by the same
conduit. A lower orifice of the valve is destined to put in communication the
intermittent charge of a gas burner fixed in the counterplate with the interior of
the cylinder by a port. A small gas burner constantly alight is parallel and tangential
to the interior face of the valve.
The valve is in addition pierced with a conduit coming out into two ports, which
must communicate at the opportune moment the one with the port of the cylinder,
and the other with the port which meets the escapement tube. The two orifices
and the counterplate of which is perforated near the intermittent burner give the
aid necessary for the combustion of the gas consumed by the burner.
The mechanism of the slide valve in conjunction with the fixed cam regulates the
moments of introduction of the detonating mixture, of the firing mixture, and of the
escape of the gases and vapours
in front of the piston. For the introduction the slide
valve is placed in such manner that the cavity puts the conduit in communication
with the interior of the cylinder by the port. While the slide valve occupies this
position the burner fixed in the counterplate, is open, and the gas which it brings
is lighted by contact with the permanent burner.
When the cylinder has taken the vertical position the introduction is stopped, the
valve is displaced, it rises a little, and the orifice is found opposite the port; there
is then communication between the burner and the detonating mixture contained
under the piston, and explosion takes place. By reason of the explosion the burner is
extinguished, to be again lighted later on when the slide valve shall descend
afresli.
When the slide valve at the botton corresponds to the firing the slide valve at

page_text: the top is arranged for the escapement; a conduit puts the interior of the cylinder
into communication with the escapement conduit by ports of the cylinder.
The escapement tube comes out into the distributing box, which it traverses, a
valve intercepting the passage of the atmospheric air. The products of explosion
driven out by the piston having a superior tension to that of the atmosphere lift
this valve, which immediately shuts again.
A cock placed beyond the valve serves to moderate the speed of the escapement,
and consequently the shocks of the piston against the bottom of the cylinder.
The space which exists between the bottoin of the cylinder and the piston being
once charged with a sufficient quantity of detonating mixture the fire is put to the
mixture, and the piston driven up, it pushes before it the air contained in the
cylinder. By the combination of the primitive gases, and by the more or less rapid
cooling of the secondary vapours and gases resulting from this combination, there is
formed in the cylinder a relative vacuum, and the interior tension is greatly inferior
to the atmospheric pressure. If therefore at the opportune moment the slide valve
has taken the position for the introduction the face of the piston which occupies the
bottom of the cylinder communicates with the atmosphere. This face of the piston
supports the atmospheric pressure, while the other face only supports the pressure
existing in the cylinder; the piston will tend therefore to return in the cylinder.
There is thus produced a suction movement, which sucks the air and gas in sufficient
quantity that when fired the detonating mixture produces an explosion violent
enough to drive the piston from the bottom to the top of the cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Ravel in the Great Seal Patent Office on the 11th April
1878.
JOSEPH RAVEL, of Paris, Boulevard de Strasbourg, No. 59, Engineer.
IMPROVED ROTARY MOTIVE-POWER ENGINE."
" AN
This rotary engine is based on the following principle-A cylinder is suspended
at the middle of its length by two trunnions of a horizontal axis, which constitutes
the shaft of the engine; in this cylinder is placed a piston without a rod, forming a
weight or block, which is alternately driven from one end of the cylinder to the
other by the expansive force of an explosive mixture or compound by compressed
air, by steam, or any other fluid. Supposing the engine at work, and that the
cylinder A (see Figure 1 of the annexed Drawings) suspended by its trunnions O is
in a vertical position, the piston block G being at the lower end of the cylinder; at
this moment the explosive compound drives the piston block to the upper end of
the cylinder, and as the engine is actuated by a continuous rotary movement the
cylinder A is at A¹ when the piston G has arrived at G¹, but at this moment the
weight of the piston acts to the right of the vertical of the axis of rotation,
the result is that the cylinder is carried round by the weight of the piston block,
and the rotary movement continues. By coupling two cylinders A and B per-
pendicularly one to the other, as seen in Figure 1, each containing a piston block G
working as above described, a more regular inovement is obtained.
It will be seen that the centre of gravity of the cylinder or cylinders is continually
displaced with reference to the axle of the trunnions, and it is precisely this which
causes the rotary movement.
Such is the principle of my rotary engine, which I call an engine with a variable
centre of gravity.
Figure 2 is a vertical section through the axis of one of the cylinders.
Figure 3 is a transverse section of the distributing trunnion O.
Figure 4 is a vertical section following the line M, N, of the explosion chamber
and of its slide valve.
Figure 5 is a horizontal section following the line P, Q, of Figure 2.
Figure 6 is an elevation on a larger scale of the explosion chamber and of its
slide valve.
Figure 7 is a horizontal section following the line R, S, R¹, S', of Figure 6.
Figure 8 is a vertical section following the line T, U, of Figure 6.
Figure 9 is a section following the line V, X, of Figure 8.
Figure 10 is a horizontal section following the line Y, Z, of same Figure 8.
The trunnion O on the left hand is pierced with four horizontal conduits; a being
the introduction of gas; b, introduction of the refrigerating water circulating
between the cylinder and its envelope; c, exit of the heated water; d, escape of 4
spent gases and products of combustion.
The trunnion O has at its extremity an enlarged bearing C, which revolves easily,
and with little friction in a fixed box or collar D. This circular collar (Figures 2
and 3) has three grooves e, e¹, e²; the groove e communicates with the conduit a;
groove e¹ with conduit b; groove e² with conduit c; and, lastly, the central 4
opening communicates with the exhaust conduit d. The gas brought by the
pipe a circulates in the groove e, and is conducted to the explosion chamber by
tubes, which are not shown in the Drawings for the sake of clearness. These tubes
are four in number, each terminating in a chamber arranged at the extremity of
each of the two cylinders.
The gases generated by the explosion of the explosive compound escape from the
explosion chambers E by the tubes i (shown cut off in the Drawing), which
terminate in the horizontal conduit d of the trunnion O, the gases then pass along
6

page_text: this conduit & through the collar D, and, by opening the valve, escape into the
atmosphere. The cock h placed between this valve and the atmosphere permits
the escape of the gases to be regulated at will, so as to moderate the shocks of the
piston block against the ends of the cylinder.
The water intended to cool the cylinder is forced by the pump P into the pipe j,
which is in connection with circular groove e¹ of the collar D; the water flows by
the conduit b and the tubes k into between the cylinder and its envelope, circulating
and cooling the parts, and leaving by tubes, not shown, connected to the conduit c,
in communication with the groove e² of the collar D, finally escaping by the exit
pipe l.
A screw Q, supported at its base by springs R, is placed at each extremity of the
cylinders A and B, in order to prevent the shock of the pistons G against the ends
of the cylinders.
I will now describe the mechanism for the distribution of the gas and of the air,
the arrangement of the explosion chambers with their slide valves, and the action
of the machine.
The explosion chamber E is placed at the end of each cylinder and permits of a
great regularity being obtained in the charges of the explosive compound (gas and
air). It is composed of a cylinder E in which moves a piston H; the rod m of this
latter is for that purpose terminated by a roller n engaged in the race of a cam F.
A distribution box K (see Figure 4, and in detail, Figures 6, 7, 8, 9, and 10) is
arranged at the extremity of this cylinder E; the rod o of the slide p is connected
to a cross piece o¹ which is fastened to the rod o³, whose roller n' is acted upon by
a second race of the cam F.
The gas for producing the explosion enters into the slide valve p by the orifice q,
then into the cavity q¹ in which air has already entered by the opening q²; the
mixture of gas and air passes through the vertical part C, which is pierced with
holes, and under the piston H by the port r. Facing the opening 8 of the fixed
counterplate t is a gas jet burning intermittently; another gas jet 8' is constantly
alight.
In front of the opening u is arranged a valve I, giving communication between
the explosion chamber E and the motor cylinder A. The axis o% of this valve (see
Figures 6 and 7) carries exteriorly a tappet v, which, at the end of the piston's
stroke, is acted upon by the rod v₁ connected to the piston rod m of the explosion
chamber; when this rod v' acts on the tappet, the valve I opens communication
between the cylinder A and cylinder E, the opposing spring x (Figures 6 and 7)
closing the valve immediately the rod v¹ ceases to act on the tappet v.
The action of the distributing mechanism of my motor is as follows:-When the
cylinder A approaches the vertical position, the piston G being at the lower end, -
the piston H of the explosion chamber E has ascended under the action of the
cam F, drawing in the mixture of air and gas. The port y of the slide valve is
then (see Figures 6 and 8) beneath the port r; the permanent gas jet 8' ignites the
jet 8.
When the explosive compound has been admitted under the explosion chamber
piston, the slide 2 ascends, the introduction of gas and air is closed, the gas jet 8
ignites the explosive compound, and the explosion takes place; the valve I (Figures
2 and 7) is opened sharply and the piston block G is immediately driven to the
upper part of the cylinder A, when it acts by its weight, as already described with
reference to Figure 1.
The piston G thus driven from one end of the cylinder to the other expels before
it the products of the preceding explosion; the piston H (see Figure 2) has for this
purpose arrived at this moment at the upper part of the chamber E, the port r
being opposite the opening of said piston, and, as before explained (in describing
the action of the valve I with reference to Figures 6 and 7) the rod v' has acted on
the tappet v, opening the valve so that the products of the explosion find an issue
by the port r, the opening z of the piston H, the cylinder E, and the tube i, which
'

page_text: is in connection with the horizontal conduit & of the trunnion O, and finally escapes
into the atmosphere through the cock h.
I may construct these machines with variable centre of gravity, of any power,
and make their constituent parts of any shapes, materials, and dimensions.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as special features of my rotary
machine,-
First. The arrangement of a cylinder or of several cylinders coupled together, in
each of which a rodless piston, forming a block or weight, is displaced at each
semi-revolution of the cylinder for the object of utilizing the displacement of the
centre of gravity to produce motive power, substantially as described and shown in
the Drawings.
Secondly. The employment of a fluid, explosive compound, steam, water, com-
pressed air, hydraulic power, or other, but more especially of an explosive compound,
such as gunpowder, dynamite, or other explosive material, to displace the piston
block in its cylinder when the latter has arrived at a vertical position, as herein-
before described and for the purposes set forth.
Thirdly. The arrangement of an explosion chamber at the extremity of each
cylinder with a distribution slide valve, arranged and worked in the manner
described, for the admittance of the mixture of gas and air in suitable proportions,
and the exit of the spent gases produced by the explosion.
Fourthly. The construction of the whole and the details of my machine, as above
described, and shown in the Drawings.
In witness whereof, I, the said Joseph Ravel, have hereunto set my hand
and seal, this Fifth day of April, One thousand eight hundred and seventy-
eight
Witness,
CHARLES ARMENGAUD,
Civil Engineer,
Paris,
Bd. de Strasbourg, 23.
JOSEPH RAVEL. (L.B.)