IMPROVEMENTS IN STEAM ENGINES AND STEAM-ENGINE BOILERS
Year: 1842

page_text: NAPIER, of Mill Wall, in the County of Middlesex, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent, under the Great Seal of Great Britain, bearing date at West-
minster, the Ninth day of August, in the sixth year of Her reign, did, for Herself,
Her heirs and successors, give and grant unto me, the said David Napier,
Her especial licence, full power, sole privilege and authority, that I, the said
David Napier, my exors, adiñiors, and assigns, or such others as I, the said
David Napier, my exors, adñiors, or assigns, should at any time agree with,
and no others, from time to time and at all times during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick upon Tweed, my Invention
of "IMPROVEMENTS IN STEAM ENGINES AND STEAM-ENGINE BOILERS;" in which said
Letters Patent is contained a proviso that I, the said David Napier, shall cause
a particular description of the nature of my said Invention, and in what
manner the same is to be performed, to be inrolled in Her said Majesty's
High Court of Chancery within six calendar months next and immediately after
the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
David Napier, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and

page_text: front elevation, of a steam engine constructed according to the first part of my
Invention. The improvement consists in so applying four light piston rods to
the same piston and continuing them upwards past the main shaft, so that the
cranks and connecting rod may work between the piston rods. a, a, a, a, are
the piston rods, which work through stuffing boxes in the usual manner, and
they are combined together at their upper ends by the cross heads, through
which cross heads the pin d passes, which receives the upper end of the con-
necting rod e, the lower end of the connecting rod e being attached to the
crank pin f; and it will be seen that the main shaft works between the piston
rods, as is shewn at Figures 2 and 3.
By this arrangement any desired length of connecting rod may be obtained,
and at the same time the number and weight of the parts employed in getting
motion from the piston to the main shaft will be reduced.
I will now describe my second improvement in the construction of steam
engines, which is shewn at Figures 4 and 5; Figure 4 being a side elevation,
and Figure 5 a front elevation; and the improvements consist in a mode of
.using two piston rods extending upwards past the shaft in such manner that
the crank to. which they give motion may work between the piston rods (and
yet obtain any desirable length of connecting rod). g, g, are two piston rods
which are affixed to the piston of a steam engine, and they work through two
stuffing boxes, as is well understood. These two piston rods are connected by
the cross head h, such cross head being guided by sliding on the guide rods i, i,
one at each end. The cross head is bent so as to allow of the working of the
connecting rodj. The cross head is attached at its upper end to the lever or beam k,
moving with the axis l. The upper end of the connecting rod is attached to
the beam k by means of the pin k, and at the lower extremity to the crank
pin m of the main shaft, such cranks working between the piston rods, as is
shewn. The cross head gives motion to the beam or lever k by means of two

page_text: links o, o, each connected at one end to the cross head, and the other end of
each is connected to a pin p affixed to the lever k, all which will readily be
understood by examining the Drawing.
I will now describe my third improvement of the steam engine. Figure 6
shews a front and side elevation of a steam engine constructed according to
this part of my Invention, and the improvement consists in a single piston rod
continuing upwards between the two cranks, and connected at. the upper end
to a double connecting rod, which passes down on each side. of the piston rod
and connects the two cranks at the lower end. 9 is the piston rod, the upper
part of which is so connected with the cross head r as to allow of the cross
head turning therein, the two ends of the cross head being guided in their up
and down motion; s, s, are the two arms of the connecting rod, their upper
ends being affixed to the cross head and their lower ends are connected to the
two crank pins t, t. by this means giving motion to the two parts v, v, of the
main shaft, and any desirable length of connecting rods may be obtained. I
would remark, that in the Drawing and description of the three arrangements
of steam engines I have not thought it necessary to shew or describe the slides
and other parts common to steam engines, my Invention not relating thereto,
and they will readily be applied by an engineer.
I will now describe my improvements in the construction of steam-engine
boilers. Figure 6* shews a vertical section, and Figure 7, a transverse section
of a boiler constructed according to this part of my Invention. u, u, represents
the external figure of the boiler, which may be varied so long as the mode of
arranging the other parts be retained; w is the furnace or fire-place with a
suitable ash-pit below. Above this fire or furnace is placed a water chamber a,
in such manner as to leave a space around it for the passage of the heated air,
flame, and vapours from the fire, there being a water space y descending from
the main boiler all round the furnace excepting at the fire door and the man-
hole into the water chamber a; hence it will be seen that the principal action
of the heat of the furnace will act on the under surface of the water chamber x,
the products of combustion passing above the chamber x acting on the series of
tubes or pipes y', by which the chamber a is connected with the main boiler,
there being also a trunk y², which connects the upper part or main boiler with
the water chamber x. The products of combustion having passed amongst the
pipes or tubes y, pass away through the chimney or funnel z, around which funnel
is applied a casing, into which the feed water is pumped, and from the casing it
flows over into the boiler. I have not thought it necessary to shew steam cocks,
or pipe, or safety valve, as these parts are common to steam boilers, and will
readily be applied by an engineer. I would remark, that it will be evident

page_text: from the above description that there will be constant flow of water into the
water chamber x, and out therefrom through the pipes or tubes y', as indicated
by the arrows.
Having thus described the nature of my Invention, and the manner of per-
forming the same, I would wish it to be understood that I make no claim to
any of the separate parts of the steam engines, nor of the boiler herein shewn
and described; nor do I confine myself to the precise details, provided the
peculiar character of either part of my Invention be retained. But what
I claim is, first, the mode employing four piston rods to the same piston,
whereby the cranks and connecting rod and main shaft may work between them,
as above described. Secondly, I claim the so combining of the use of two
piston rods, whereby the connecting rod and the cranks may work between the
two piston rods, as above described. Thirdly, I claim the mode of combin-
ing two connecting rods worked by one piston rod, such two connecting rods
giving motion to two cranks affixed to two parts of the main shaft, as above
described. And, fourthly, I claim the mode of constructing a steam boiler by
applying a water chamber a over the furnace, and connecting such chamber a
by numerous upright pipes or tubes with the main boiler, as above described.
In witness whereof, I, the said David Napier, have hereunto set my
hand and seal, this Ninth day of February, in the year of our Lord
One thousand eight hundred and forty-three.
AND BE IT REMEMBERED, that on the Ninth day of February, in the
year of our Lord 1843, the aforesaid David Napier came before our said Lady
the Queen in Her Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stamped according to the tenor of
the Statute made for that purpose.
T
-nom ane pro me to meat and my "Crenigay to top many ang pape
sand eight hundred and forty-three.