CERTAIN NEW METHODS OF MANUFACTURING AND CONSTRUCTING STEAM ENGINES
Year: 1799

page_text: TO ALL TO WHOM. THESE PRESENTS SHALL COME, I, WILLIAM
MURDOCK, of Redruth, in the County of Cornwall, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by
His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, on or about the Twenty-ninth day of August last past, did
give and grant unto me, the said William Murdock, my executors, 'adminis-
trators, and assigns, His especial licence, full power, "sole priviledge and
authority, that I, the said William Murdock, my executors, administrators,
or assigns, during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend my Invertion therein mentioned, to
wit, "CERTAIN NEW METHODS OF MANUFACTURING AND CONSTRUCTING STEAM
ENGINES," within that part of Great Britain called England, the Dominion of
Wales, and Town of Berwick-upon-Tweed; in such manner as to me, the said
William Murdock, my executors, administrators, or assigns should'seein meet;
to have, hold, exercise, and enjoy the said licence, powers, priviledges, and
advantages therein granted, or mentioned to be granted, unto me,' the said
William Murdock, my executors, admors, and assigns, for and during and
unto the full end and term of fourteen years therein expressed; in, which said
Letters Patent thero is (amongst other things) contained a proviso that if I,
the said William Murdock, should'not particularly describe and ascertain the
nature of my said Invention; and in what manner the same was to be per-
formed, by an instrument in writing under my hand and seal, and cause'
the same to be inrolled in the High Court of Chancery. within one calendar

page_text: month next and immediately after the date of the said Letters Patent,
that then the said Letters Patent, and all liberties and advantages whatsoever
thereby granted, should utterly cease, determine, and become void, as in and
by the said recited Letters Patent, reference being thereunto had, will more
fully appear.
NOW KNOW YE, that in compliance with the said proviso, I, the
said William Murdock, do hereby describe and ascertain the nature of my
said Invention, and the manner in which the same is to be performed,
as follows (that is to say): --
First, I bore the metallic cylinders and pumps of steam engines by means of
an endless screw, turned by a mill or steam engine, working into a toothed
wheel, which produces a more smooth and steady motion than is obtained by
any of the methods now in use. The toothed wheel is fixed upon or connected
with a rod or axis, which carries the cutter wheel or borer, as is delineated at
Figure 1 and 2 of the annexed Drawing, where.A represents the endless screw
fixt upon a shaft turned by a mill or steam engine, and B. B, the toothed wheel
fixt upon an axis C, connected with the boring rod E., The endless screw is
here .represented as placed below the wheel; but may be placed 'above it, or in
any other convenient position. The screw is best made of cast or wrought iron
or brass, and the wheel of wood or of iron, brass; or other metal, with solid
teeth of the same, or with wooden teeth fixt in a metallic or wooden rim in
the usual, manner. The screw is made of so many threads, and the wheel
with such number of teeth as: are necessary for giving to the boring rod the
velocities which are usual in the common process of-boring metallic cylinders
and pumps. The nearer the thread of the screw approaches to a right angle
with its axis the. steadier, will the motion be: 'The one I have commonly used
has three threads, is sixteen inches in diameter, and the advance by one revo-
lution is six inches, but any other number of threads might be used, regard
being always had to the angle which the. 'thread -makes with its axis according
to the rule above given... I also turn pistons, wheels, covers of cylinders, and
other pieces of metal. by fixing or attaching them firmly to the end D of the
axis C, above mentioned, or to any other axis turned by an endless screw, as
has been described.
Secondly, I simplify the construction of the steam vessel and steam case in
engines constructed upon. Mr. Watt's principles, by casting the steam case of
one intire cylinder (to which the cover and bottom of the working cylinder are
attached); within this I place the working cylinder or steam vessel, which
is fitted tight to the steam case at both ends by conical or spiggot joints
or by a conical joint at one end and at the other by a packing of hemp o

page_text: :
other proper substance caulked in and kept in its place by the top or
bottom of the cylinder according as the caulked joint is at the upper or lower.
end; or Icast.the cylinder and steam. case in one piece of a proper thickness,
then, by means of a circular saw. or boring tool made in the form of a hollow
cylinder of cast or sheet .iron or other metals, with cutters or teeth upon its
edge, at one end. I bore, a cylindric, interstice; between the steam case and the
steam vessel, leaving these two cylinders attached, to each other at one end.by.
the solid metal, and I, close up, the interstice of the other end, by a solid ring of
metal and packing or cement. kept, in its place by the cover or bottom of the
cylinder according as it is the upper or lower end of the cylinder. In Fig. 3. A
represents the steam cylinder, and B the.steam case. LC, C, and D, D, are
the conical joint at the top and bottom. E is the cylinder lid, and .F the
cylinder bottom. In Fig. 4 A represents the steam vessel, and B.the steam
case, which are cast, the whole length, in one cylinder,, of the thickness shewn
at C, and the cylindric interstice D., D., bored by means of the circular saw or
boring tool represented in Fig. 5, and.6. This circular saw is formed. of a tube
A, of the diameter of the interstice to be bored, and longer than it, to afford
convenience, for,, fixture at the end. B. At the end C, a projecting ring of
metal D is, cast, or fixt.on for holding, the steel. cutters E, E, E, E, (the
number of which is regulated by the diameter of the tube) which are fixt to
the ring by the, means of screws; as shewn in Fig. 6, or they may be wedged
in, notches, left or made in the ring for that purpose. Each of these cutters
must be of less, breadth than the, interstice to be bored, and are placed as
shewn in the Drawing. Appertures, a, a, a, a, are left or made in the inside
and outside of the cutter ring D, to allow the exit of the cuttings or borings.
The circular motion is given, either to the, boring tool or to the cylinder, as
may be found convenient... Note, the new Invention in this latter case. does.
not consist in the boring tool, but in the casting of the steam case and steam
vessel in one mass, and then boring, the interstice between them.
Fy
5
Thirdly, I simplify the construction of the steam valves or regulators and
working gear in the improved engine of Mr. Watt's construction, called the
double engine., Fig. 7, 8,, and .9 represent the cylinders of one of those
engines with my new working gear. and steam valves applied thereto instead
of the gear, and valves now in use. A, A, is the steam vessel of the engine;
B.. the piston, and C the piston rod; D is the upper opening or steamway,
and E, the lower opening.or steamway of the cylinder; F is the steam case.
To this aflix my new working gear and steam valves in manner following:-
G, G, is a semi-cylindric tube or pipe, but which may be cylindrie, triangular,
or of any, convenient form, communicating with the steam vessel, and firmly

page_text: fixed to or connected with the steam case, or with the steam vessel itself
where no steam case is used. This tube has an opening H on its side for
the admission of steam from the boiler, and another opening I at bottom,
which leads to the condenser; at the top it is covered with a plate T, having
a hole and stuffing box to admit the sliding rod K, which is joined to or con-
nected with an inner moveable pipe or tube L, L, open at both ends, to one
side of which are affixt the solid plates or valves M, M, intended to slide upon
the plates N, N, and occasionally to cover and uncover the upper and lower
openings of the cylinder D & E, opposite to these plates. The remaining cir-
cumference of the tube L, L, is furnished with projections or flanches U, U, of
brass or other metal, with an interstice W, W, between them, to receive a
packing of hemp or other proper substance, which will permit the tube L, L,
to move up and down steam-tight in the fixt tube G, G. O, O, are openings
in the tube G, G, shut with plugs or plates screwed or otherwise fixt to it,
which may be removed to repair the packing. When the tube L, L, is in the
position shewn in Fig. 7, the steam enters through the steam pipe H, and
filling the interstice S, S, between the tubes G, G, and L, L, passes into the
cylinder at the upper opening D, at the same time the steam contained below
the piston rushes out to the condenser through the lower opening E; a vacuum
being thus formed below the piston it descends, and when it has got near the
bottom of the cylinder a bracket P, attached to the top of the piston rod C, strikes
a projection Q, upon the sliding rod K, and causes the tube L, L, to descend
to the position represented in Figure 8; the valves M, M, by this motion slide
past the openings of the cylinder, and the steam which is above the piston
issues at the upper opening and passes down the tube L, L, into the condenser,
at the same time the steam continuing to pass from the boiler through the
pipe H, and the interstice S, S, enters the cylinder by the lower opening E,
and forces up the piston and piston rod with the bracket P, which, near the
end of the ascending stroke, encounters another projection R of the sliding
rod K, and raises the tube L, L, into its former position of Fig. 7, and the
operations are repeated.
I have represented one of the simplest methods of working these valves by the
bracket affixed to the piston rod, but they may also be worked by a plug tree
nxt to the beam-or-by-other-means;-or, instead-of-causing-the-inner-pipe and
valves to slide up and down in the manner described, I also construct them
so as to perform a circular motion, or a reciprocating motion, through part of a
circle within the outer pipe G, G, as shewn in Fig. 10 to 14. The simplest form
of the working part of the pipe G, G, and of the valves is a cylinder or a cone.
The collars or valves U, U, surround the pipe L, L, at each end, and are pro-

page_text: vided with packing in the interstice W, W, Fig. 10, 11, and 13. Each of these
collars or valves has two appertures or steamways X and Y, the former serving
to introduce the steam into the steam cylinder, and the latter to convey it to
the condenser, the aperture Y in one collar or valve corresponding to the upper
opening of the cylinder, at the same time the apperture X in the other collar
or valve corresponds to the lower opening, and vice versa, as may readily be
understood by inspecting Fig. 12, which is a view of the inner pipe with its
collars or valves. Fig. 13 is a cross section at 1, 1, Fig. 12, upon an enlarged
scale; through one of these valves or collars (a) in Figs. 10, 11, & 12, is a
curved or conical bar of steel, or other metal, which resting upon the fixed
transverse bar (6), of brass or other metal, serves to support the weight of the
pipe L, L, and its appurtenances, without preventing the passage of the steam
through that pipe to the condenser. The other parts in these Figures are
similar to those of the first variety which are expressed by the same letters.
One of many methods of communicating the requisite motion to the tube L
and its collars or valves, is represented by Figs. 10 and 14, wherein C is a
plug tree moved by the engine d, d. Two clamps or pegs of wood or other
substance fixed to the plug tree, which clamps in the course of their motion
acting upon the arm (f) alternately produce an angular motion of the Y shaft
(9), which, by means of the arm h, the rod i, the lever k, and the spindle K,
produces the motion in the pipe and collars or valves in such manner that when
the piston of the engine descends the aperture X of the upper collar or valve
forms an open communication betwixt the interstice S and the upper end of
the cylinder, while the aperture Y of the lower collar or valve forms a commu-
nication betwixt the lower part of the cylinder and the condenser, 'as is shewn
in Fig. 10, and vice versa, as is shewn in Fig. 11.
Note, the new Invention in this case consists in connecting the upper and
lower valves so as to be worked by one rod or spindle, and in making the
stem or tube. which connects them hollow, so as to serve for an eduction
pipe to the upper end of the cylinder, by which means two valves are made
to answer the purpose of the four used in Mr. Watt's double engine.
.
Fourthly, I construct rotative steam engines upon a new plan, as follows:-
In Fig. 15, A and B are two pinions or wheels working into each other with
teeth of the form represented in the Drawing, or of any other form which can
be made to fit each other; these wheels turn round in a box C, C, C, C, to the
circumference of which the ends of the teeth apply during their motion, and
move along it steam-tight by means of stuffings or packings of hemp or other
proper substance, shewn at D, D, D, and well supplied with oil or tallow; these
wheels are each terminated by planes at right angles to the axis, and fitted

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tight by packing or stuffing to the ends or covers E, E, Fig. 15, 16, and 17, of
the box in which they are included, in which ends one or more openings F, F,
are left to introduce the packings of, the teeth,, and, are closed with doors when
the machine is set to work. The axis of one or both the wheels, passes, through.
one or both the end plates in collars made tight by hemp or other substances
well greased, and motion is given from one or more of these axes to the ma
machi-
nery required to be moved or turned by the engine, and to the pump for
exhausting the condenser, which pump and condenser are constructed in any
of the ways practised by Mr.. Watt, or, in the manner represented in Fig. 15
and 16. The wheels may have their axes either perpendicular or horizontal,
in which latter way they are drawn.. Steam being admitted in a continued
stream from the boiler by, the pipe or channel G, and a vacuum being formed
in the condenser (by the introduction of steam through the pipe H, the cock K
of which is shut before the engine begins to, work), the steam acts upon the
teeth of the wheels A and B, and causes them to turn round in contrary direc-
tions, as shewn by the >, and consequently produces a rotative motion in
the axes of the wheels, and the machinery hereto annexed..
In witness whereof, I, the said William Murdock, have hereunto set my
hand and seal, this Twenty-sixth day of September, in the year of
..our Lord One thousand seven hundred and ninety-nine.