IMPROVEMENTS IN MOTIVE POWER ENGINES TO BE WORKED BY STEAM OR OTHER AERIFORM FLUID."
Year: 1880

page_text: LETTERS PATENT to Peter William Willans, of Bow, in the County of
Middlesex, for an Invention of "IMPROVEMENTS IN MOTIVE POWER ENGINES
TO BE WORKED BY STEAM OR OTHER AERIFORM FLUID."
PROVISIONAL SPECIFICATION left by the said Peter William Willans
at the Office of the Commissioners of Patents on the 16th April 1880.
PETER WILLIAM WILLANS, of Bow, in the County of Middlesex.
"IMPROVE-
MENTS IN MOTIVE POWER ENGINES TO BE WORKED BY STEAM OR OTHER AERIFORM
FLUID."
This Invention has for its object improvements in motive power engines to be
worked by steam or other aeriform fluid.
I arrange three single acting cylinders side by side, usually in an inverted
position. Over these cylinders, but with an exhaust chamber between, I set three
other and smaller cylinders. All the cylinders are provided with pistons. There are
three piston rods, each carrying a large and a small piston. The pistons working
in the larger cylinders are coupled by connecting rods with cranks on a crank shaft;
these cranks are set at angles of 120 degrees apart. The piston rods extend beyond
the upper pistons, and at the top of the smaller cylinders they enter and work
through guide tubes or sleeves which fit them steam tight. At the top of all there
is a chamber, to which the boiler steam is admitted. The upper ends of the guide
tubes or sleeves are open to the steam chamber, and the piston rods in working
through them act as valves; the tube or sleeve is perforated at the side, and when
the piston rod descends so far as to uncover the perforations the steam passes into a
passage leading to the top of one of the small cylinders; similarly as it rises it cuts
off the steam from this cylinder. There are apertures or ports in the sides of the
small cylinders; each is connected by a passage with the top of one of the larger
cylinders. Thus there are three sets of parts, and calling these sets one, two, and
three respectively, the routine in working is as follows:-The upper end of piston
rod one serves as a valve to admit steam upon the top of small piston rod two, and
this piston in turn, after travelling a certain distance, allows the same steam
to expand on to the top of large piston three. At the end of the downward
stroke of large piston three, the small piston two, which is now rising, passes over

page_text: the port in the side of its cylinder, and leaves a free passage from large cylinder
three into the lower part of small cylinder two, which is in permanent communica-
tion with the exhaust chamber.
Similarly the course of the steam may be traced, commencing with piston rod
two acting as a valve and admitting steam to small cylinder three, which after-
wards expands in large cylinder ono.
Or commencing with piston rod three, admitting steam to small cylinder one,
which afterwards expands in large cylinder two.
The engine works in the manner described whilst working expansively, but
when full power is required a stop cock is opened which admits the boiler steam
continuously to the upper parts of the small cylinders.
The engine can be reversed by means of a multiple cock which transposes the
passages, so that small cylinder two may discharge into large cylinder one, and not
into large cylinder three, as previously described, and similarly in each case.
If it be desired that the engine when reversed should work expansively a
second multiple cock is applied on the passages, by which steam cnters the small
cylinders.
It is not essential that the large and small pistons of each set should be on the
rod, they may be otherwise connected so as to work in unison.
The same observation applies to the admission valves; they need not be
prolongations of the piston rods, but may be connected otherwise to move in
unison with them.
It is not essential that the admission valves should be prolongations of the
piston rods, but other forms of valves may be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter William Willans in the Great Seal Patent Office on the 16th
October 1880.
PETER WILLIAM WILLANS, of Bow, in the County of Middlesex. " IMPROVE-
MENTS IN MOTIVE POWER ENGINES TO BE WORKED BY STEAM OR OTHER AERIFORM
FLUID.".
This Invention has for its object improvements in motive power engines to be
worked by steam or other acriform fluid.
I arrange three single acting cylinders side by side, usually in an inverted
position. Over these cylinders, but with an exhaust chamber between, I set three
other and smaller cylinders. All the cylinders are provided with pistons. There
are three piston rods, each carrying a largo and a small piston. The pistons
working in the larger cylinders are coupled by connecting rods with cranks on a
crank shaft; these cranks are set at angles of 120 degrees apart. The piston rods
extend beyond the upper pistons, and at the top of the smaller cylinders they enter
and work through guide tubes or sleaves which fit them steam tight. At the top
of all there is a chamber, to which the boiler steam is admitted. The upper ends
of the guide tubes or sleeves are open to the stoam chamber, and the piston rods
in working through them act as valves; the tube or sleeve is perforated at the
side, and when the piston rod descends so far as to uncover the perforations tho
steam passes into a passage leading to the top of one of the small cylinders;
similarly as it rises it cuts off the steam from this cylinder.
There are apertures or ports in the sides of the small cylinders; each is connected
by a passage with the top of one of the larger cylinders. Thus there are three sots
of parts, and calling these sets one, two, and three respectively, the routine in
working is as follows:-The upper end of piston rod one serves as a valve to
admit steam upon the top of small piston two, and this piston in turn, after
travelling a certain distance, allows the same steam to expand on to the top of
large piston three. At the end of the downward stroke of large piston three the
small piston two, which is now rising, passes over the port in the side of its
cylinder and leaves a free passage from large cylinder three into the lower part
of small cylinder two, which is in permanent communication with the exhaust,
chamber.
Similarly the course of the steam may be traced, commencing with piston rod
two acting as a valve, and admitting steam to small cylinder three, which after-
wards expands in large cylinder one, or commencing with piston rod three,
admitting steam to small cylinder one, which afterwards expands in large cylinder
two.
The engine works in the manner described whilst working expansively, but when
full power is required a stop cock is opened, which admits the boiler steam
continuously to the upper parts of the small cylinders.
The engine can be reversed by means of a multiple cock which transposes the
passages, so that small cylinder two may discharge into large cylinder one, and not
into large cylinder three, as previously described, and similarly in each case.
If it be desired that the engine when reversed should work expansively a
second multiplo cock is applied on the passages, by which steam enters the small
cylinders.
It is not essential that the large and small pistons of each set should be on the
same rod, they may be otherwise connected so as to work in unison. The same
observation applies to the admission valves; they need not be prolongations of the
piston rods, but may be connected otherwise to move in unison with them.
It is not essential that the admission valves should be prolongations of the piston
rods, but other forms of valve may be employed.

page_text: In order that my Invention may be fully understood I have shown in the
Drawings hereunto annexed a motive power engine constructed as above described.
Figure 1 is a vertical section of the engine; Figure 2 a cross section of the same,
Figure 3 a horizontal section taken through the steam supply chamber at the top;
A, A, A, are three single acting cylinders side by side; the pistons of these cylinders are,
as shewn, coupled by connecting rods with three cranks on a crank shaft B, the cranks
being set at angles of 120 degrees apart or thereabouts. Above the cylinders A are
three other cylinders C, C, C, of smaller diameter. The piston rods of the pistons of
the cylinders A extend upwards through the end covers of these cylinders, and carry
the pistons which work in the cylinders C. The lower ends of the cylinders Care
open to an exhaust chamber C* interposed between the cylinders A and C. The
piston rods extend upwards beyond the pistons of the cylinders C and entor and
work within guide tubes or sleeves D which rise up from the top of the cylinders C.
The upper ends of the tubes or sleeves D open into a chamber E; to which the
boiler steam is admitted.
The tubes or sleeves D are perforated at their sides as shown. The perforations
open into passages leading to the top of one or other of the smaller cylinders C.
The upper ends of the piston rods thus work as valves to adinit and cut off steam
to and from the upper ends of the cylinders C. Similarly there are apertures or
ports in the sides of the smaller cylinders C opening into passages leading to the
top of one or other of the larger cylinders A, and the pistons of these cylinders
act as valves to control the adinission of steam from these cylinders to one or
other of the larger cylinders A.
The pairs of high and low pressuro cylinders are marked Nos. 1, 2, and 3, and
the admission of steam to the cylinders C from the steam chamber E and from
the cylinders C to the larger cylinders A is effected in the manner above described
when working expansively. When full power is required steam is admitted
continuously from the steam chamber E to the upper ends of the smaller cylinders C.
This is effected by moving a slide valve F contained in the steam chamber E so as
to uncover ports which open into the passages which lead from the upper ends
of the cylinders C to the perforations in the tubes or sleeves D. This valvo is
shewn in Figures 2 and 3, but other arrangements of valve might be used for
the same purpose.
When the engine is required to be reversed it may be made capable of reversal at
full pressure only, as shewn at Figures 1 and 2, by a rotating multiple cock G, by
means of which the passage leading from small cylinder No. 1 instead of dis-
charging into large cylinder No. 2 can be made to discharge into large cylinder
No. 3, whilst small cylinder No. 2 is made to discharge into large cylinder No. 1,
and small cylinder No. 3 into large cylinder No. 2. This transposition of tho
passages is effected by turning the cock G through one sixth of a circle so as
to change the position of its ports from that shown at Figure 1 to that shewn at
the diagram, Figure 4.
When the cock G is turned so as to reverse the engine, the slido F is shifted by
turning the screw F¹ so as to open the ports which the slide previously covered
and admit steam continuously to the upper ends of the smaller cylinders. If
it be desired that the engine when reversed should work expansively, a second
multiple cock is applied on the passages which lead to the upper ends of the
Binaller cylinders, as shewn in the section, Figure 5. The multiple cocks are
constructed in the manner described in the Specification of a foriner Patent
granted to me, No. 974, in the year 1874, so that I have not thought it necessary
to describe their construction more fully.
It is not essential that the large and small pistons of each set should be on the
same rod, they may, as above stated, be otherwise connected so as to work in
unison; it is also not essential that the pistons of the smaller cylinders, should
have the same length of stroke as the pistons of the larger cylinders; they might,
for example, be both coupled to a rocking lever, through which motion is

page_text: transmitted to a crank on the crank shaft. The engine also may be horizontal, or
vertical, or otherwise, as desired.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim,―
First. In motive power engines having three single acting cylinders and three
piston valves working in unison with them, the so making the engine that when
desired the valves may also act as high pressure pistons, substantially as described.
Second. In motive power engines constructed as herein before described, the
employment of a pass valve whereby when desired the working steam or fluid
can be admitted continuously to the back of the high pressure pistons, so that they
then act solely as valves.
Third. The construction of motive power engines, substantially as herein before
described and illustrated in the Drawings annexed.
In witness whereof, I, the said Peter William Willans, have hereunto set my
hand and seal, this Sixteenth day of October, in the year of our Lord
One thousand eight hundred and eighty.
PETER WILLIAM WILLANS. (L.S.)