AN IMPROVED ROTARY ENGINE
Year: 1884

page_text: I, DANIEL GALLAFENT of Woolwich in the County of Kent Mechanic-do hereby
declare the nature of my invention for "AN IMPROVED ROTARY ENGINE" to be as
follows:-
This invention relates to rotary motive power engines pumps, blowers, or
exhausters of the kind for which Letters Patent wero granted to ino bearing dato
the 16th day of July A.D. 1880 and numbered 2936. In engines pumps, blowers,
or exhausters of the kind described in the specification of the said patent,
I employ a slotted disc by which the motion of the revolving pistons is transmitted
to the shaft through which power is to be transmitted from the engine to
machinery or other point of resistance, or through which power is to bo transmitted
to the pump, blower, a exhauster, as the case may be. This disc being eccentric
to the main cylinder also regulates the motions of the pistons in such manner that
they act on the disc with varying leverages; it is contained in and works
steamtight in a chamber between the two acting cylinders. I have found in
practice that it is very difficult to keep the said disc steam tight and have
therefore devised the improved arrangements which form the subject of the present
invention. These arrangements consist as follows:-
Instead of arranging the disc in a chamber between two cylinders in which it
has to be fitted and to work steam tight, I arrange it wholly outside of and
independent of the cylinder and of any steam connections whatever. For this
purposo I mount the disc on the end of the shaft intended to be driven by the
engine and place it so as to face the end of the working cylinder but eccentric
thereto. The working cylinder is fitted with three segmental pistons placed
longitudinally therein, each of these pistons is carried by one of three shafts which
pass through the centre of the working cylinder. These shafts are concentric with.
each other, two of them being hollow and passed over the third which may be
solid. They all extend out through a stuffing box at the end of the cylinder and
are provided with arms or cranks carrying pins which take into three equidistant
radial slots in the before mentioned disc. As this disc stands eccentric with the
working cylinder the pistons in the latter act through their respective arms or
cranks on the slots of the disc with varying leverages in a manner similar to that
described in the specification of my before-mentioned patent,

page_text: Instead of three independent pistons, four pistons may be employed connected
together two and two in which case there will be two slots on the external disc.
Other numbers of pistons, shafts and slots may be employed but I prefer three
single or two double ones as being the most practical and giving the best result.
When three pistons are employed the maximum degree of separation of any two
pistons does not exceed about one third the circumference of the cylinder, the
consequence is that the latter is filled once only during a revolution and therefore
yields only half the power of a reciprocating engine of the same capacity and same
number of revolutions per minute.
When two double pistons are used steam may be allowed to enter on both sides
of the shaft at the same time whereby the strain is equalized and as the cylinder is
filled twice in each revolution double the power is given off as compared with a
cylinder of same capacity with three pistons.
The inlet and outlet ports for steam, liquid, or air are arranged at the end or
ends or at the circumference of the working cylinder and the pistons are arranged
to open and close them as they pass in front of them during their revolutions.
The above description is made to refer to rotary steam engines but it is
obvious that similar arrangements are equally applicable for pumps, blowers, or
exhausters.
Din Buble of Iran 100.

page_text: "
I, DANIEL GALLAFENT of Woolwich, in the County of Kent do hereby declare
the nature of the said invention for "AN IMPROVED ROTARY ENGINE and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement referenco being had to the accom-
panying sheet of drawings and to the letters and figures marked thereon that is to
Bily-
This invention relates to rotary engines of the kind for which Letters Patent
were granted to me bearing date the 16th day of July A.D. 1880, and numbered
2936. In the specification of the said patent is described a slotted dise by which
the motion of the revolving pistons is transmitted to the shaft through which
power is to be conveyed from the engine to machinery or other point of resistance,
or through which power is to be transmitted to the engine when it is used as a
pump, blower or exhauster.. This disc being eccentric to the main cylinder also
regulates the motions of the pistons in such manner that they act on the disc with
varying leverages; it is contained in, and works steamlight in a chamber between
the two working cylinders. I have found, in practice, that it is very difficult to
keep the said disc stram-tight, and have therefore devised the improved arrange-
ments which form the subject of the present invention, and are illustrated in the
accompanying sheet of drawings in which Figure 1 is an elevation of one of my
improved rotary engines, Figure 2 a sectional plan, Figure 3 a transverse section
through the cylinder at 1-1 looking towards the left in Figure 1, Figure 4 an end
clevation with the pedestals supporting the transmitting shaft removed for the
sake of clearness, Figure 5 a view of the inside of the back cylinder cover showing
the steam and exhaust ports, Figure Gelovations of the working pistons showing
how they are fitted together and Figure 7 shows the shafts which carry the said
pistons in the cylinder.
Instead of arranging the disc in a chamber between two cylinders in which it
has to be fitted and adapted to work steam-tight as in the abovementioned patent,
No 29:36, I now arrange it wholly outside of and independent of the working
cylinder and of any steam connections whatever. For this purpose I mount the
disc A on the end of the shaft B intended to be driven by the engine, and place it
so as to face the end of the working cylinder C, but eccentric thereto. The
working cylinder is fitted with three segmental pistons D, D¹ and D³ placed
longitudinally therein, each of these pistons is carried by one of three shafts E E¹
and E which pass through the centre of the working cylinder C. These shafts are
concentric with each other, two of them E and E being hollow, and passed over
the third E which may be solid. They all extend out through a stuffing box Fat
the end of the cylinder C next the disc A, and are provided with arms or cranks
G, G¹ and G carrying pins H H H with T heads which take respectively into
the equidistant radial slots or grooves III in the beforementioned dise A. These
pins either turn freely in holes in the arms or cranks, and their heads formed
solid with them, or the pins are secured in or forined solid with the arms or
cranks, and turn freely in holes in their heads. As this disc A stands eccentric
with the working cylinder C, the pistons D D D³ in the latter, act through their
respective arms or cranks G G G and pins H, H¹, H on the sides of the slots or
grooves 1 112 of the disc A with varying leverages, in a manner similar to that
described in the specification of my beforementioned patent. For example, in the
sectional Figure 3 steam port J is shown open to the space between the two

page_text: pistons D1 and D2, and the steam pressure would tend to turn one piston round the
centre in one direction and the other piston in the reverse direction, but as the
pin H2 belonging to the piston D2 occupies a position in the slot or groove I³ of
the disc A which is further removed from the centre of the said disc than the pin
H, belonging to the piston D¹, in the slot or groove I', the pressure on the piston
D2 acts with greater leverage or turning power on the disc A than the pressure on
the piston D¹ and the consequence is a rotary motion of all the pistons round the
axis of the cylinder in the direction of the arrow, each piston in succession coming
into the position where it acts with more leverage on the disc A than the piston
behind it. The speed of motion of each of the pistons varies during a complete
revolution in proportion to the varying leverages at different points in the
revolution due to the eccentricity of the centre of the disc A with reference to the
centre line or axis of the cylinder, the result being that each of the spaces between
two adjacent pistons is alternately increased by steam entering (and if desired
expanding) between them and decreased as such steam is exhausted through the
exhaust port K. In the figure the space between the pistons D and D¹ is shown
in communication with the said exhaust port K.
In the engine illustrated in the drawings the inlet and outlet ports J and K for
steam, liquid or air are arranged at the end of the working cylinder, and the ends
of the pistons D, D', De open and close the said ports as they pasa in front of them
during their revolutious. If preferred however these inlets and outlets may be
arranged at the circumference of the working cylinder.
Instead of three independent pistons, four pistons may be employed connected
together two and two as illustrated in Figures 8 and 9 in which the pistons.D¹ D' arc
connected to one boss and D³ D' to another, and in this case there are only two slots
or grooves 11' on the external disc A and two corresponding arms or cranks G Ɑ¹
and pins H H on the piston shafts. A greater number of pistons than three may
be used in the working cylinder and corresponding und suitable numbers of slots.
or grooves in the disc, but I prefer three single, or two double, pistons as being the
most practical, and giving the best results.
When three pistons are employed, the maximum degree of separation of any two
pistons does not exceed about one third the circumference of the cylinder, the
consequence is that the latter is filled once only during a revolution, and therefore
yields only half the power of a reciprocating engine of the same capacity and same
number of revolutions per minute. When two double pistons are used, steam may
be allowed to enter on both sides of the shaft at the same time, that is to say,
between D¹ and D³, and between D' and D' in Figure 8, whereby the strain is
equalized and, as the cylinder is filled twice in each revolution, double the power is
given off as compared with a cylinder of the same capacity with three pistons.
The above description is made to refer to rotary steam, air or hydraulic engines,
but it is obvious that similar arrangements are equally applicable for pumps,
blowers, or exhausters, the only difference being, that in the case of the steam, air,
or hydraulic engine, power is transmitted from the engine to the shaft B, whilst in
the case of a pump, blower, or exhauster, power is transmitted through the shaft B
to the engine.
The above described rotary engine may be arranged to work compound, or high
and low pressure, by employing two sets of pistons in one cylinder, the one set
being separated from the other by a disc rotating in the cylinder with them, as
illustrated in Figures 10 and 11, in which D and D' represent a pair of high
pressure pistons, and D2 D3 a pair of low pressure pistons, the disc interposed
between the high and low pressure pairs being secured with the high pressure
piston D' the low pressure piston D2 and the crank arm G to the hollow shaft M,
and the high pressure piston D the low pressure piston 13 and the crank arm Gi
to the internal shaft N. The steam after operating to separate the high pressure
pistons D D is allowed to expand into the space between the low pressure pistons
DD and, after separating them, to exhaust into the atmosphere or into a
condenser. The pins H H on the crank arms G G₁ take into radial slots or

page_text: ooves in a disc in the same way as in the examples already described above. It
ill be obvious that the compounding can also be effected by arranging two
parate cylinders and sets of pistons, the high pressure cylinder being either
orter or smaller in diameter, or both shorter and smaller in diameter, than the
w pressure cylinder according to circumstances and the degree of expansion of
eam required.
Having now particularly described and ascertained the nature of my said
vention, and in what manner the same is to be performed, I declare that what
claim is
1. The improved rotary engine constructed with three or more segmental pistons
secured to corresponding shafts passing through the centre of the working
cylinder, and connected by means of arins or cranks and pins with the
radial slots or grooves in a disc revolving with its shaft externally to and
eccentrically with the centre or axis of the working cylinder, as herein-
before described, and illustrated in Figures 1 to 7 of the drawings hereto
annexed.
2. The combination of four segmental pistons connected together two and two
and revolving concentrically with the working cylinder, with the slotted or
grooved disc, external to, and eccentric with, the said working cylinder, as
herein before described, and illustrated in Figures 8 and 9 of the drawings
hereto annexed.
3. The combination of two sets of segmental pistons revolving concentrically
with the working cylinder, and connected by crank arms and pins with a
slotted or grooved disc external to, and eccentric with the said working
cylinder, so as to form a compound or high and low pressure arrangement,
as horeinbefore described, and illustrated in Figures 10 and 11 of the
drawings hereto annexed.