AN IMPROVED REVOLVING ENGINE AND PUMP, APPLICABLE AS A FLUID METER
Year: 1869

page_text: LETTERS PATENT to John Charles Wilson, of 26, Martin's Lane,
Cannon Street, City of London, Mechanical Engineer, for the
Invention of "AN IMPROVED REVOLVING ENGINE AND PUMP, APPLICABLE
AS A FLUID METER."
Sealed the 31st May 1870, and dated the 3rd December 1869.
PROVISIONAL SPECIFICATION left by the said John Charles Wilson
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd December 1869.
I, JOHN CHARLES WILSON, of 26, Martin's Lane, Cannon Street, City
of London, Mechanical Engineer, do hereby declare the nature of the
said Invention for "AN IMPROVED REVOLVING ENGINE AND PUMP, APPLICABLE
AS A FLUID METER," to be as follows:-
This Invention relates to an improved revolving (or rotary) engine
and pump. The following improvements are common to both engines
and pumps:
Firstly. In revolving engines and pumps hitherto constructed one part
of the fixed cylinder, called the large cam, being that part which is not

page_text: concentric but eccentric to the internal revolving cylinder or piston,
and touches it at a certain point has been made in a separate piece from
the fixed cylinder and fitted into it with H shaped ends. This is an
objectionable construction for the following reasons:-First, the labour
and expense of fitting it in are great; second, being a separate piece of
metal from the fixed cylinder it does not always expand and contract
alike, and causes jamming of the parts and friction; and, third, the
Hshaped ends wear away the surfaces of the moveable slides or pistons
which rub against them unequally. This latter defect is of very great
importance, as it will soon be observed that a smooth, even, and con-
tinuous metal surface all round the interior part of the fixed cylinder is
necessary, when it is considered that the centrifugal force (and the
speed) of the moveable slides which bear against that surface is very
great. For instance, in only a small 9-inch engine the centrifugal force
of the slides, which weigh each 1 lbs. is at 600 revolutions per minute,
as much as 90 lbs. Instead of this objectionable separate large cam
with H shaped ends I construct my large cam in one solid piece with
the cylinder, thereby ensuring equal expansion and contraction; and I
avoid the H shaped ends, which are made for the purpose of allowing
the steam or water to escape past the moveable slides during the time
they are moving out and in, and thereby cause equal pressure on both
sides of them and reduce the friction of their movement; and I construct
my large cam instead with solid ends without any recesses whatever,
except the mouths of the ports (if they can be so called) which are kept
as narrow as possible; and to accomplish the object of allowing the
steam or water to pass the moveable slides I make recesses not in my
cylinder where the slides bear against, but in the cover or covers thereof
at the end or ends of the slides where they have no pressure outwards.
Secondly. In revolving engines and pumps hitherto constructed the
moveable slides have been actuated or guided by only one small cam
placed in the centre of the cylinder. This is objectionable, first, on
account of its giving a narrow and unsteady base to the slides; and,
second, on account of its being placed in a position where the oil does
not easily reach it to properly lubricate it, the consequence being that
such single cams wear fast away. I construct my revolving engines and
pumps with two small cams placed one at each end of the moveable
slides, thereby giving them a wide and steady base, affixed one to each
cover of the cylinder where the oil quickly reaches them. Instead of

page_text: cams I can actuate my moveable slides with springs placed underneath
them, but I prefer cams as being more steady and certain in their
action.
Thirdly. In revolving engines and pumps hitherto constructed the
moveable slides have been made with the whole of their surfaces truly
planed, fitted, and scraped so as to fit exactly the grooves of the
revolving cylinder in which they work. This causes great labour and
expense, as the whole of the two surfaces of each slide are thus fitted
with great accuracy. To reduce and save this labour and expense I
construct my slides with grooves or recesses in their surfaces, leaving
only narrow raised portions to be fitted as above. I thus reduce the
fitted surfaces by more than one half. My grooves or recesses have the
further advantage of holding the oil and effectually lubricating the
grooves as the slides move out and in. But in addition to these two
advantages my recessed or grooved slides possess another, which is very
important. It has been mentioned before that the centrifugal force of
these slides is very great, causing considerable friction against the
internal surface of the fixed cylinder, and so detracting from the useful
power of the engine. Now my recesses leave a shoulder on the slides
against which the steam presses tending to force them inwards, and
I can by regulating the depth of this shoulder counterbalance the
centrifugal force to any extent desired.
The following improvements relate to the steam engines only. One
great objection hitherto to all revolving engines has been the great
consumption of steam in proportion to the power given off, on account
of there being little or no expansion of the steam in such engines. To
remedy this defect I construct special expansive revolving engines as
follows: Instead of making them with only one cylinder with the
steam from the boiler entering at one side and exhausting into the air
on the other, I construct my said engines with two or more cylinders,
the first being the smallest, the next a number of times larger, and
so on, and these cylinders exhaust the one into the other, the first or
smallest receiving the steam from the boiler. For instance, taking an
engine of 9 inches diameter I make the first cylinder, say, 2 inches
wide, with an area of moveable slide, against which the steam at full
boiler power presses of 1.6875 square inches. This cylinder exhausts into
the second, which is made, say, 9 inches wide (also 9 inches diameter)
with an area of moveable slide of 6 square inches, or 4 times greater

page_text: than the other, so that the steam is expanded as many times, and so on.
It will be seen that the first or small cylinder becomes in fact the
measure of the quantity of steam used at boiler pressure. I use any
number of cylinders or any proportion according to the number of times
I wish to expand. I place them either close together or separate, in the
latter case connecting them with pipes, but I prefer the former. And I
place them either on the same shaft or on separate shafts connected by
gearing or couplings, but I prefer the former. I thus form a simple
expansive revolving engine without the use of any valves and cut off
gearing.
My expansive revolving engines are made either condensing or
non-condensing.
Secondly. In order to simply reverse or stop my revolving engines
I construct them with a slide valve covering the two ports with an
exhaust port between, so that by simply moving the slide valve so as to
make cither port communicate with the steam or exhaust I reverse the
motion of the engine, or by covering the two ports I stop it.
Thirdly. I regulate the speed of my revolving engines, not by
connecting the governor with a valve in the steam pipe, but in the
exhaust, which more effectually regulates them and allows the full
boiler pressure always to reach the engine, avoiding "throttling;" this
regulation arrangement I apply to the pumps; a governor of any kind,
as, for instance, a float rising or falling with the buoyancy of the water
in a cistern or boiler I attach to a valve in the pump delivery pipe, and
as it opens or closes this valve the speed of the pump or pumping engine
is regulated accordingly. Thus I construct a simple self-acting revolving
pumping engine, say, for boiler feeding purposes, the full pressure of
steam being always on the pistons of the engine ready to act when the
valve in the pump delivery pipe is opened.
Fourthly. I construct my revolving pumps with a set of wheels
worked by the main shaft connected with a pointer or pointers on an
index or indices, which are so marked as to shew the quantity of water
which has passed through the pump. It thus becomes a fluid meter.
In regard to engines I do not confine my Invention to steam, but also
use water pressure or hot air; and in regard to pumps I do not confine
my Invention to water, but I also pump air or gas, either exhausting or
compressing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Charles Wilson in the Great Seal Patent
Office on the 3rd June 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CHARLES WILSON, of 17, Gracechurch Street, in the City of London,
Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of December, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did for Herself, Her heirs and successors,
give and grant unto me, the said John Charles Wilson, Her special
licence that I, the said John Charles Wilson, my executors, adminis-
trators, and assigns, or such others as I, the said John Charles Wilson,
my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVED REVOLVING ENGINE AND PUMP, APPLICABLE AS A FLUID METER,"
upon the condition (amongst others) that I, the said John Charles
Wilson, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Charles Wilson, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the accompanying
Sheet of Drawings, and to the letters of reference marked thereon, that
is to say:-
My Invention relates to revolving (or rotary) engines and pumps,
Marcamants ora common to both engines and

page_text: First. In all revolving engines and pumps with a concentric internal
revolving cylinder or piston there is a part of the external fixed cylinder
which is called the large cam, being that part which is eccentric to the
internal revolving cylinder and touches it at a certain point, this large
cam performs the function of acting as a base to the propelling power
and of stopping the connection between the exhaust and the pressure
sides of the engine or pump. This large cam I construct in one solid
piece with my external fixed cylinder not in a loose piece fitted in for
the following reasons:-1. I thereby ensure the equal expansion and
contraction of the metal of this cam with that of the external cylinder,
which is of importance in these engines as they are fitted metal to metal
and any unequal expansion or contraction of their parts must cause
either leakage or friction, and thus detract from the efficiency of the
machine. 2. I avoid the expense of fitting in, which is considerable.
I bore out or otherwise machine tool the working surface of this large
cam at the same time as that of the external fixed cylinder of which it
forms a part. In the Drawing hereunto annexed, this large cam is
marked A, see especially Figures 1 and 2.
Secondly. I construct my ports for the ingress or egress of the steam,
water, or other fluid used in these machines nearly the whole length
across the external fixed cylinder, and as narrow as possible in the other
direction (giving an area of a little more than that of the annular space
between the external fixed cylinder and the internal revolving cylinder
or piston). My reason for this mode of construction instead of making
the ports wide or long in the direction of the internal periphery of the
external fixed cylinder and cutting away a large portion of the large
cam A is that I avoid that unequal wear of the outer edges of the piston
slides D, D, (see Drawing hereto annexed, Fig. 1,) which takes place
when there is a large space cut out of the external fixed cylinder in the
direction of their motion. This wear must be considerable in such
engines as the centrifugal force of these piston slides is great. C is the
internal revolving cylinder or piston; B, the external fixed cylinder; and
E, the annular space between them.
Thirdly. As the large cam A is eccentric to the revolving piston C, it
will be observed that the piston slides D, D, travel outward and inward
the distance of the annular space E as they pass over the surface of the
large cam A. It is desirable while they are so travelling that the
pressure or exhaust should be equal on both sides of them, so as to

page_text: avoid pressure to one side of the grooves in which they work and thereby
friction. To accomplish this object I construct recesses in the cover or
covers of my external fixed cylinder at the end or ends of the said piston
slides, which recesses allow the steam, water, or other fluid in a state of
pressure or exhaust to pass round the end or ends of the said piston
slides, and so render equal the pressure on both sides of them, F, F, are
the said recesses (Fig. 3). The advantage of this mode of construction
is, that as the piston slides have no pressure outwards at their ends
they are not worn unequally by my recesses at these parts.
Fourthly. I guide the piston slides D, D, in their motion outwards
and inwards by two small cams, one affixed to each cover of the external
fixed cylinder. I thereby ensure a wide base and steady motion for the
piston slides combined with a large wearing surface, and one which is
easily oiled. G, G, are the two said small cams. Instead of these cams
springs to keep pressing the piston slides outwards may be used, but
I prefer the cams as being more certain and steady in their action.
Fifthly. I construct the piston slides D, D, in the following greatly
improved manner:-Instead of making them with the whole of their
surfaces on each side planed and fitted very exactly as they require to
be to the grooves in which they work, I construct them with recesses
in their surfaces as shewn in Figures 1, 4, and 5, leaving only narrow
raised portions which have to be fitted in, and I thereby reduce materially
the cost of construction. Further, the inner recess which is always
within the groove, being filled with any suitable lubricating material
acts as a lubricator to the surface of the groove and thus reduces the
friction of the slides in their movement outwards and inwards. Further,
the outer recess having a shoulder only upon one side, viz., the inside
acts the following important part:-The centrifugal force of these piston
slides at the usual speed of these engines is as has been before remarked
great, and necessarily tends to cause friction against the surface of the
external fixed cylinder, but the pressure of steam or other fluid used
in the machine against this single shoulder on the outer recess tends to
press my piston slide inwards and so acts as a counterbalance to the
centrifugal force, and it is obvious according as this shoulder is made
deeper or narrower so may the centrifugal force be counteracted to any
desired extent. d' and are the said recesses in my piston slides.
Figures 1, 2, 3, 4, 5, 6, 7, and 8 of the annexed Sheet of Drawings shew

page_text: the construction of my improved revolving engine and pump applicable
as a fluid meter. The following improvements relate to engines only :-
Sixthly. A great objection hitherto to all revolving engines has been
the great consumption of steam (and fuel) in proportion to the power
given off, there having been in them little or no expansion of the steam,
it issuing through the exhaust port at the original pressure. It is not
convenient in these engines to use eccentrics and the usual cut-off valve
gear on account of the great speed at which they work. I construct my
revolving engines with a special expansive arrangement as follows:-I
construct them with two or more cylinders instead of one, placed end to
end on the same shaft or detached, the cylinders of different sizes
exhausting the one into the other, commencing with the smallest and
ending into the largest, by these means I obtain gradual expansion to
any extent desired without the use of complicated valve machinery.
Take for instance an engine of 9 inches diameter in which I wish to
expand the steam 4 times, I construct the first cylinder say 24 inches
wide, giving an area of piston slide of say of 1.6875 square inches, which
has on it the full pressure of steam in the boiler, then I construct a
second cylinder, say 9 inches wide, with an area of piston of say 6-75
square inches, or four times greater, into which the first cylinder exhausts,
and the steam is thus expanded from 1 to 4, or reduced to about
one-fourth of its original pressure. A wider cylinder or more and wider
cylinders may be added to expand farther. I have described the above
as if the cylinders were all of one diameter, but that is not necessary so
long as an increased area of piston slide is given; I prefer, however, to
make them of the same diameter and of different lengths. Figures 9,
10, 11, and 12 shew my revolving expansive engine as above described,
viz., with 2 cylinders placed end to end on the same shaft, B being the
smallest cylinder, and B² the largest; H is the steam pipe from the
boiler into B; I is the exhaust pipe from B into B; and K is the
exhaust pipe from B into the atmosphere or a condenser. Instead of
the cylinders being connected together and on the same shaft as I have
shown them they may be detached with separate shafts and exhaust pipes
connecting them. The opening or shutting of a simple cock or valve on
the pipe H is all that is necessary to stop or start these engines. It
will be observed the first cylinder B becomes in fact a measure of the
steam used at boiler pressure. I make these engines either condensing

page_text: or non-condensing; in the former case the exhaust from the last or
longest cylinder simply passes into a condenser in the usual manner, the
said condenser being conveniently exhausted by a detached revolving
steam air pump, In constructing these expansive revolving engines
I keep. the piston slides D, D, of the various cylinders all in one
horizontal linc. I prefer to construct the details of these expansive
revolving engines in the manner shewn at Figures 1, 2, 3, 4, 5, 6, 7,
and 8, but other descriptions of revolving engines may be adapted to
work expansively in a similar manner.
Seventhly. In order to simply reverse the motion of expansive
revolving engines when a reversing engine is required, I construct them
with a slide valve on the top of the first or smallest cylinder, which slide
valve covers the two steam ports with an exhaust port between them as
shewn in Fig. 13, by simply moving this valve so as to make the port b¹
communicate with the boiler as shewn the engine will revolve in the
direction of the arrow, by moving it so as to make the port 6² commu-
nicate with the boiler (as shewn in the dotted lines) the engine will
revolve in the direction of the dotted arrow. The exhaust port b
communicates with the valve chest of the second cylinder of the engine,
entering it in the same way as the pipe H is shewn to enter this first
valve cliest, and in the valve chest of this second cylinder there is a
second slide valve precisely similar to the above which is moved at the
same time and in the same manner by any convenient mechanical
appliance. The exhaust pipe of the second cylinder either discharges
into the atmosphere or into a condenser or into the valve chest of a third
cylinder if more expansion is required, this third cylinder being fitted
with another similar slide valve and so on.
Eighthly. I construct my revolving engines in the following manner
so as to efficiently regulate their speed. I place a throttle valve of the
usual construction in the exhaust pipe not in the steam pipe attached
to the governor. By opening or closing this valve by means of the
governor the speed of the engine is regulated in a better and more
efficient manner than if the valve were placed in the steam pipe there
On account of their
being especially no wiredrawing of the steam.
being no fly wheel on these revolving engines there is no objection to
thus throttling the exhaust. I apply this construction to my revolving
pumps and especially to steam pumps so as to make them self-regulating
in regard to the quantity of water delivered. Any suitable valve or

page_text: cock acting casily without friction is placed on the delivery pipe of the
pump and attached to a float which rises or falls (and opens or shuts
the valve) along with the water in the cistern or boiler which is being
supplied. The steam pump therefore revolves at a speed proportioned
to the opening of this valve, the steam being constantly on the engine
part of it ready to act whenever the said valve is opened, Fig. 14 shews
this construction.
Ninthly. I construct my revolving pumps as above described with a
train of wheels which receive their motion from the main shaft and are
connected with pointers on the face of an index or indices, which are so
marked as to shew the quantity of water that has passed through the
pump. It thus becomes an efficient fluid meter.
In regard to engines I do not confine my Invention to steam, but I
also use water power or hot air, and in regard to pumps I do not confine
my Invention to water but I also pump air or gas either exhausting or
compressing.
Having now described the nature of my said Invention and in what
manner the same is to be performed, I declare that what I claim as
the Invention to be protected by the hercin-before in part recited Letters
Patent is,-
First. The employment of recesses F, F, in the end cover or covers of
the external fixed cylinder of revolving engines and pumps and meters
substantially as and for the purpose herein described.
Secondly. The employment of outer recesses d¹ in the pistons slides of
revolving engines and pumps and meters. substantially as and for the
purpose herein described.
Thirdly. The employment of inner recesses & in the piston slides of
revolving engines and pumps and meters substantially as and for the
purpose herein described.
Fourthly. Constructing revolving engines with two or more cylinders
of different sizes to exhaust one into the other, as herein described.
Fifthly. Constructing revolving engines with two or more cylinders
of different sizes to exhaust one into the other in combination with slide
valves on each cylinder, worked at the same time for the purpose of
reversing the engine, as herein described.
Sixthly. The placing a throttle valve worked by the governor in the
exhaust pipe of revolving engines to regulate their speed, also in the

page_text: delivery pipe of revolving pumps worked by revolving engines to
regulate the delivery of water from the pump as herein described.
In witness whereof, I, the said John Charles Wilson, have here-
unto set my hand and scal, this Third day of June, in the year of
our Lord One thousand eight hundred and seventy.