Improved Reversing Mechanism for Steam and other Motor Engines.
Year: 1889

page_text: Date of Application, 20th June, 1839
Complete Specification Left, 18th Mar., 1990-Accepted, 19th Apr., 1890
PROVISIONAL SPECIFICATION.
Improved Reversing Mechanism for Steam and other Motor
Engines.
I, FRANCOIS DAUGY of 23 Boulevard de Strasbourg Paris, France, do hereby
declare the nature of this invention to be as follows:-
My invention relates to a construction of reversing mechanism which allows the
direction of motion of a motor engine to be with facility instantaneously reversed
without material shock, notwithstanding the engine may be running at a high speed.
The mechanism is applicable to motor engines of all descriptions, whether
horizontal, vertical or inclined. The reversing mechanism consists essentially in
an arrangement whereby the excentric or excentrics that work the slide valve or
valves can be turned instantaneously through an angle of 180° on the engine shaft.
For this purpose the excentrics are formed in one with or fixed upon a sleeve loose on
the engine shaft, this sleeve being carried round with the shaft, by means of a projection
on the latter, which can bear against the one or other of two shoulders in a circular
groove in the sleeve; these shoulders are so arranged that the shaft can turn half
round relatively to the sleeve in moving its projection from the one shoulder to the
other one.
If now during the running of the engine in the one direction or the
other the excentric sleeve be turned half round upon the crank shaft, it will be
evident that the slide valves will thereby be worked in the contrary direction to
that in which they previously worked, and that consequently the motion of the
engine will be at once reversed.
This reversal of the position of the excentric sleeve is effected at will by the engine
itself by means of an auxiliary shaft which is put in gear with the engine shaft when
required. The auxiliary shaft is for this purpose carried in a frame pivotted at one
end and capable of being raised and lowered by a lever at the other end; the shaft
has fixed upon its one end a toothed wheel capable of gearing with a toothed wheel
fixed on the engine shaft, so as to be rotated thereby, while at the other end it carries
a circular disc with milled or roughened periphery which can be brought in contact
with the surface of the eccentric sleeve. When the engine is running, the said frame
with the shaft and its toothed wheel and disc are in the lowered position, so that the
wheel and disc are out of gear; but when it is desired to reverse the motion of the
engine, the frame is raised so as to bring the toothed wheel and disc in gear, where-
upon, as the toothed wheel on the auxiliary shaft is made of smaller diameter than the
one on the engine, shaft, and the disc. is of larger diameter than the toothed wheel, the
disc will cause the excentric sleeve to turn considerably faster than the engine shaft,
and consequently will turn it through an angle of 180° upon the latter until the
projection on the shaft comes in contact with the shoulder opposite that with which it
was previously in contact, thereby reversing, the position of the excentrics and slides,
and consequently also the motion of the engine.
.
For bringing the eccentrics into the position for running in the desired direction
on first starting the engine, another disc with roughened surface is mounted on a
shaft carried by. a. bracket that can be slid on the engine framing so as to bring the
disc in contact with the excentric sleeve, but which is acted upon by a spring so as to
keep the disc out of gear. For bringing the disc in contact, the sliding bracket is
acted upon by a cam turned by means of a lever, after which the disc is turned by a
crank handle and bevil gearing, so as to rotate the excentric sleeve in whichever
direction is necessary for bringing the excentrics, into the required position..

page_text: The above described mechanism is particularly applicable for reversing the motion
of direct acting motors such as those for rolling mills, pumps &c.
Dated this 90th
C T
1000
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Reversing Mechanism for Steam and other Motor
Engines. -
I, FRANCOIS DAUGY of 5 Rue Guilbem, 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 construction of mechanism which allows the direction of
motion of a steam engine or other fluid pressure motor, to be instantaneously reversed
without material shock notwithstanding that the engine may be running at a high
speed. The reversal of the direction of motion can be effected both in a forward and
in a backward direction without stoppage of the engine.
This invention is applicable to engines of all kinds, vertical or horizontal or with
inclined cylinders.
The annexed drawings illustrate by way of example a two cylinder vertical steami
engine of the "steam hammer" type with reversing mechanism according to this
invention.
Fig. 1 is a sectional elevation of the engine taken in a vertical axial plane to show
the mechanism for reversing the direction of motion.
Fig. 2 is a side elevation of the same, the lower part being shown in section.
The engine proper comprising the cylinders, rods, connecting rods, and slide
valves, does not offer any peculiarity.
The novelty consists principally in the arrangements hereinafter described which
allow of instantaneously altering through an angle of 180° the position of the
eccentrics in relation to the cranks. The two eccentrics a, a which operate the
slide valve rods b, b, form part of a single sleeve mounted with a certain amount of
play on the driving shaft O. Motion is cominunicated to the eccentrics from the said
driving shaft O by means of a key c projecting from the shaft O and rigidly fixed to
the said shaft.
This key extends around one fourth of the circumference and engages in a circular
groove d of the eccentric sleeve, the groove d being made full for a fourth of the
circumference so as to provide an abutment e e¹.
The key d of the shaft by acting upon one or the other extremity of this
abutment e el, imparts motion to the eccentrics a a. If whilst the engine is rotating
in one direction, a relative shifting or displacement on the shaft of 180° be imparted
to the eccentric sleeve, the order of distribution of the motive fluid is changed; and
the shaft will immediately rotate in the reverse direction.
This relative shifting or displacement of the eccentric sleeve on the shaft is effected
by the engine itself by means of an auxiliary shaft A which can be connected at
will with the driving shaft.
The
This auxiliary shaft A is carried by a support B (shown in plan in Fig. 3) capable
of being caused to oscillate on pivots ff by the action of an operating handle c.
shaft A carries at one end a toothed wheel D adapted to gear with a wheel E
mounted on the driving shafts O; at the other end the shaft A carries a disc G
having a rough surface adapted to be brought into frictional contact with a circular
part 9 formed on the eccentric sleeve.
In normal working the support B of the shaft A is in its lowered position and
the wheel Dis. out of engagement with the wheel E. Since the disc G does not

page_text: touch the sleeve of the eccentrics, the sleeve rotates in that direction of the shaft in
which the key c abuts against one extremity (it may be for example e as shown in
Figs. 2 and 4) of the inner shoulder e e' of the sleeve.
If now the support B be suddenly raised, the wheel D will engage with the
wheel E on the driving shaft, and the shaft A will be rotated in the contrary
direction to the shaft O. The disc G having been brought at the same time into
contact with the eccentric sleeve will impart to the latter a relative displacement by
causing it to rotate on its shaft. When this relative displacement has reached 180°
the distribution of the slide valves is the opposite to that which was previously in
operation, and the direction of the movement will be changed abruptly (Fig. 5).
Furthermore as soon as this change is effected the key c of the shaft abuts against
the other extremity e¹ of the inner shoulder of the eccentric sleeve, in such a manner
that the latter will be immediately carried round in the direction necessary for
operating the slide valves so as to maintain the new order of distribution of motive
fluid.
By again raising the shaft A a reverse movement of the eccentrics will be effected,
and the direction of the movement will be again reversed.
In order to enable the engine to be started in the opposite direction to that at
which it was running when it was stopped it is necessary to give to the eccentric
sleeve a relative movement on the shaft such that it shall take up the position suitable
for being driven round by the shaft in the required direction.
This movement of the eccentric sleeve on the driving shaft while at rest is imparted
by means of the device shown in side elevation in Fig. 2, and separately in rear
elevation in Fig. 6 and in plan in Fig. 7. This device comprises a disc H adapted
to be brought into frictional contact with the part g of the eccentric sleeve. The said
disc H having a rough surface and being mounted on a shaft is carried by a carriage
or support I capable of sliding on the framing X.
This support I has a constant tendency to be drawn back by a spring h acting upon
a spindle fixed to the said carriage I.
When it is desired to move this carriage forward it is necessary to operate the
handle of a shaft k carrying a finger which is caused to abut against a support /
fixed to the framing of the engine. The shaft of the disc H is also connected by
bevel gear L with a small shaft carrying a crank handle M.
When the carriage supporting the disc H has been thus moved forward so as to
bring the latter into contact with the eccentric sleeve, the crank handle M is rotated
in the proper direction whereby the disc H is caused to rotate and thereby displace
the eccentrics on the driving shaft in such a manner as to bring the same into position
for obtaining the desired direction of movement.
This system of reversing the motion is particularly applicable to direct acting
motors, such as for example motors employed for driving rolling mills, pumps &c.
In the case of an engine driving a rolling mill the shaft O may be prolonged and
connected directly to the shaft of the first set of rolls.
This reversing mechanism is particularly suitable for rolling mill engines as it
dispenses with many difficult and tedious operations.
Fig. 8 illustrates a further modification of reversing mechanism according to this
invention.
In this arrangement the relative displacement of the eccentric sleeve on the driving
shaft is effected by the engine itself by means of an auxiliary shaft which may be
coupled at-will with the driving shaft. This auxiliary shaft A is carried by a support,
and is furnished at one of its extremities with a toothed wheel D adapted to engage
with the wheel E of the driving shaft D. At the other extremity of the shaft A is
mounted a wheel G adapted to engage with the circular part 9 of the eccentric sleeve
which is provided with a gear wheel H.
In normal working the gear wheels of the shaft A are out of engagement with the
toothed wheels E and H of the driving shaft O by reason of the empty spaces or
portions not furnished with teeth of the gear wheels G and D (Fig. 8). If it is
required to change the direction of motion suddenly in one or the other sense, use is

page_text: .
anade of the lover which is of sufficient, length to be able to engage with one of the
teeth of the gear wheel. D, and by depressing this, lever the, wheel Dis rotated, so as
to re-engage with the wheel Hand the wheel G is caused to engage again with the
wheel situated above, whereby, the direction of the movement being reversed, a
reverse operation of the eccentrics and consequent change of motion is,effected.
To start the engine in the opposite direction it is merely necessary to raise, the
lever.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to-be performed; I declare that what I claim in a
steam or other finid pressure motor is :-
[
1. The hereinabove described reversing mechanism in which the eccentric cor
eccentrics is, orcare mounted, on the shaft, in such a way that it or, they has or have
an amount of play on the shaft equal to half a revolution, and ris, or are capable of
being displaced through this half revolution by means of gearing actuated by the
engine itself whilst working, and by a device operated by manual power when the
engine is in a state of rest.
2. In reversing mechanism of the kind referred to in the previous claim the; use
-of toothed wheels brought into and out of engagement by means of a suitable lever
substantially, as described with reference to Fig. 8 of the drawings.
3. The reversing mechanism substantially as described with reference to and
shewn in Figs. 1 to 7 and in Fig. 8 of the drawings.
Dated this 18th day of March 1890.
F. DAUGY,
Per L. W.