A COMBINED AND COMPOUND ENGINE FOR APPLYING MOTIVE POWER AND FOR MEASURING FLUIDS
Year: 1856

page_text: LETTERS PATENT to Thomas Duncan, of Liverpool, in the County of
Lancaster, Civil Engineer, for the Invention of "A COMBINED AND
COMPOUND ENGINE FOR APPLYING MOTIVE POWER AND FOR MEASURING FLUIDS."
Sealed the 14th January 1857, and dated the 16th July 1856.
PROVISIONAL SPECIFICATION left by the said Thomas Duncan at the
Office of the Commissioners of Patents, with his Petition, on the
16th July 1856.
I, THOMAS DUNCAN, of Liverpool, in the County of Lancaster, Civil Engineer,
do hereby declare the nature of the said Invention for "A COMBINED AND COM-
POUND ENGINE FOR APPLYING MOTIVE POWER AND FOR MEASURING FLUIDS," to be as
follows:-
These improvements are chiefly applicable to water-power engines, and are
peculiarly applicable to measuring the flow of water or other fluids passing
through the machine.
This Invention consists of two cylinders, placed side by side and parallel to
each other, and which it is prefered to cast in one piece when intended to be
used as a fluid meter. The sides of the cylinders are fitted with slide valves,
the valve rods working and being parallel to the piston rods. The two cylinders
are fitted with suitably formed pistons, which it is proposed to make of a com-
position of gutta percha and black lead. These pistons are fitted with suitable
rods which work through stuffing boxes formed in the cylinder covers.
The

page_text: packings prefered to be used in the stuffing boxes are double-cupped lethers,
like those used in bydraulic presses. The covers of the cylinders are formed
with a slight projection on the sides nearest the ports so as to allow a portion
of the metal on the inside of the covers to be removed, so as to enlarge the
mouths of the ports opening into the cylinders without unduly interfering with
the length of the stroke of the pistons. On the end of each of the piston rods
a longitudinally slotted cross head is formed, having a guide rod (or rods)
projecting from the outer (or reverse) side to the piston rod, which works
through suitable guides. On the side of the slotted cross head there is a stud
formed, upon which is mounted a drag link, which actuates a rocking lever,
communicating motion to the valves through connecting rods, which connect
and form the valve motion. The driving shaft is placed at a right angle to
the piston rods, and is provided with cranks, having studs or crank pins on one
side of their outer ends, which take into the longitudinal slots formed in the
cross heads. On the driving shaft a worm or screw motion is formed, actuating
the wheelwork forming the counters, which are provided with indexes, pointers,
and so forth, for registering the motion of the engine, and thereby denoting
the quantity of fluid passing through the machine. The power is taken off
the driving shaft by straps and friction pulleys, or in any other convenient
manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Duncan in the Great Seal Patent Office on the
16th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
DUNCAN, of Liverpool, in the County of Lancaster, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of July, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign, did
for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Duncan, Her special licence that I, the said Thomas Duncan, my
executors, administrators, and assigns, or such others as I, the said Thomas
Duncan, 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 "A COMBINED AND COMPOUND ENGINE

page_text: FOR APPLYING MOTIVE POWER AND POR MEASURING FLUIDS," upon the condition
(amongst others) that I, the said Thomas Duncan, my executors or adminis-
trators, 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 Thomas Duncan, 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 Drawings, and the letters and
figures marked thereon (that is to say) :-
These improvements are chiefly applicable to the construction of motive-
power engines intended to be worked by the pressure of water supplied to the
cylinders of the engine by a suitable feed pipe or pipes, and are peculiarly
suitable to measuring the flow of water or other fluids passing through the
machine.
To construct a machine according to this my said Invention, I place two
cylinders side by side and parallel to each other, and which cylinders I prefer
to cast in one piece when intended for a liquid meter. The sides of the
cylinders are fitted with slide valves, the slides of which it is preferred to form
of "vulcanite" or hard india-rubber, as being best calculated to stand the
action of the liquids passing through the machine. The two cylinders are
fitted with suitably formed pistons, which I prefer to make from a composition
of a mixture of gutta percha and black lead, as I have found by practical
experience that this compound is well suited for the purpose, as it is but
slightly, if at all, affected or acted upon by water. These pistons are fitted
with suitably formed rods, which I prefer to construct of iron surrounded with
brass, and work through stuffing boxes formed in the cylinder covers. The
packing I prefer to use in the stuffing boxes are double-capped leathers, like
those commonly used in hydraulic presses. The covers of the cylinders are
formed with a slight projection on the sides nearest the ports, to allow a portion
of the metal of the inside of the covers to be removed (or omitted), so as to
enlarge the mouths of the ports opening into the cylinders without unduly
interfering with the length of the stroke of the pistons. To each of the outer
ends of the piston rods I attach a longitudinally slotted cross head, having a
guide rod or rods projecting from the outer or reverse side to the piston rod,
which work through suitable guides. Between the two piston rods, and at a
right angle thereto, I mount a driving shaft, which has attached to each end o

page_text: crank, which has a fixed stud or crank pin projecting from the outside of the
outer end, and forms the axis of a friction pulley working within the slot in the
cross head, and through which motion is conveyed to the driving shaft. The
slots in the cross heads are made to depart slightly from a right line to allow
for the lap of the valve; but straight-sided slots may be used if a small
amount of play be allowed at the connections or joints between the piston rods
and the cross heads, which may be conveniently done by fitting the ends of the
piston rods with a small fixed collar, playing and confined between two suitable
collars or bearings, having an india-rubber washer on each side to prevent a
jarring motion. The faces of the valve seats may be parallel, or at an angle
to the cylinders, as may be preferred. When the faces of the valves are
parallel with the cylinders, I attach the valve rods by "drag links" to the
cross heads by means of studs formed on the cross heads, and which works
within the longitudinal grooves of the "drag links;" or I attach the valve rods
to rocking levers, which are actuated by "drag links" connected to the cross
heads of the piston rods. When I form the valve seats at an angle to the
cylinders, I incline them towards the driving shaft when I prefer to work the
valves by eccentrics on the driving shaft, as is well understood. On the driving
shaft a worm or perpetual screw is formed, which actuates an obliquely toothed
wheel, which is mounted upon a small shaft having an endless or perpetual
screw formed on its outer end. This shaft I mount at a right angle to the
driving shaft. The screw on the outer end of the small shaft actuates a
suitably toothed wheel upon which the index dial may be mounted, so as to
rotate therewith, having a fixed pointer to indicate its motion; or, it may be
used to work a train of wheels, and a rotating pointer or pointers on the face
of a suitably graduated fixed index dial or dials, as may be deemed most
advisable, for the purpose of registering the motion of the machine, and thereby
denoting the quantity of liquid passed through the engine. The power can be
taken from the driving shaft by straps and friction pulleys, or in any other
convenient manner; or the power, if desirable, can be taken off from the
ends of the guide rods by means of connecting rods and cranks.
That this my said Invention may be the more readily seen and understood,
I have hereunto annexed Drawings of so much of a small motive-power engine
and liquid meter, constructed according to one of the modifications of my plan
as will be necessary to illustrate the practical application of the Invention.
Like letters marked thereon are intended to denote similar parts.
Figure 1 is an external side elevation, showing the working portion of the
machine enclosed in an iron case; Figure 2 is a longitudinal vertical sectional
elevation, taken from the points a to 6, Figures 3 and 4; Figure 3 is a cross

page_text: sectional elevation, taken from the points c to d, Figures 1, 2, and 3;
Figure 4 is a top view of the apparatus, having a portion of the upper part of
the casing surrounding the working parts removed, and also the cover from
above one of the valves, for the purpose of exhibiting a half plan of the internal
arrangements.
A is one of two cylinders, which are laid side by side and parallel to each
other (and in these Drawings are shown placed in an horizontal position); B
is the work piston, which it is proposed to make of a composition formed by
mixing together gutta percha and black lead, and which are fitted with C, the
piston rod, which it is proposed to make of iron cased with brass, and which
works through D the stuffing box, which I propose to pack with double-cupped
leathers, similar to those used in hydraulic presses; d, a small cavity for the
reception of a suitable substance for lubricating the piston rod; E is the inlet
or feed pipe; F, outlet pipe, but the position of which may be varied to suit
circumstances; G, the valve box; G¹, valve slide, which in this modification
of the Invention works in an oblique direction. The valve slides it is preferred
to form a "vulcanite" or hard india-rubber. H, the cylinder ports; I, the
exhaust or discharge port; K, valve rod, working through L, valve box glands,
which I also propose to pack with double-cupped leathers, as commonly used
in hydraulic presses; M, a longitudinally slotted cross head, which is made
fast to the outer end of the piston rod, and which is constructed with and
carries on the front or outer side N, a guide rod; O, guide, through the eye
of which the guide rod (N) works; P, main shaft; Q, bearings for main
shaft; R, cranks, steaked to the outer ends of the driving shaft (P); S, crank
pin or stud, which projects into the slot in the cross head (M), and is
surrounded by T, a friction roller, through the edge of which the cross head
gives off the power to the crank. It will be observed that the slot in the cross
head deviates slightly from the vertical line. This is done to allow for the lap
of the valve slide, and to enable the sister engine to carry the crank over the
centre. U, the eccentric wheels on the main shaft for working the valves; V,
eccentric straps, which are connected to the valve rods by W, connecting
pieces, which are screwed on to the outer ends of the rods (the screw being
sufficiently long to allow the lead of the valves to be regulated thereby), and
are jointed to the eccentric straps by X, a joint pin; Y, the driving wheel or
friction pulley on main shaft. A is a perpetual screw motion formed on the
main shaft for working the indexes, and which actuates B, a toothed wheel,
which is mounted upon the end of C, a light shaft, which has a screw cut on
the outer end, which gives motion to D, a revolving index dial; E, angular
support for bearing the index shaft (C), and the axis of the index dial (D);

page_text: F, outer cases enclosing the working parts of the machine; G, hollow tubes
attached to the outer end of the outer casing for the guide rods (N) to work
into, to prevent the necessity of elongating the body of the enclosing case; H,
box or case for protecting the indexes; K, a padlock used to prevent the
outer case of the machine being sureptitiously removed.
Having now fully described and ascertained the nature of this my said
Invention, I wish it to be understood that I do not confine myself to the
precise details or dimensions given in the foregoing description; but what I do
claim is,
First, the combination or combinations of the various parts herein-before
described, or any mere modification of the same, for the construction of motive-
power engines and fluid meters.
Secondly, the peculiar methods of allowing the motion of each crank during
the lap of the valve.
Lastly, the use of a composition formed of gutta percha and black lead when
applied to the construction of pistons for hydraulic engines.
In witness whereof, I, the said Thomas Duncan, have hereunto set my
hand and seal, this Fifteenth day of January, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
WILLIAM WALKER,
of 44, Castle Street, Liverpool.
THOMAS (L.s.) DUNCAN.