CERTAIN IMPROVEMENTS IN THE STEAM ENGINE
Year: 1818

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, J, WILLIAM
CHURCH, late of Upper Clifton Street, Finsbury Square, in the County of
Middlesex, but now of Turner Street, Commercial Road, in the same County,
Gentleman, 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, the Eighth day of April, in the fifty-eighth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
William Church, His especial licence, that I, the said William Church, my
executors, administrators, or assigns, or such others as I, the said Willian
Church, my executors, administrators, 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, and also within
all His Majesty's Colonies and Plantations abroad, my Invention of "CERTAIN
IMPROVEMENTS IN THE STEAM ENGINE;" in which said Letters Patent there is
contained a proviso obliging me, the said William Church, by an instrument
in writing under ny hand and seal, particularly to describe and ascertain the
nature of my said Invention, and in what manner the same is to be performed,
and to cause the same to be inrolled in His Majesty's High Court of Chancery
within four calendar months next and immediately after the date of the said
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
William Church, do hereby declare that my Invention doth consist in sundry
improvements in steam engines, both condensing and high pressure, and in the
boilers of the same, which are described and ascertained in manner following,
reference being had to the Figures and Drawings annexed, with the more
particular explanations hereunder written (that is to say) :—
I do declare that my improvements in condensing steam engines do consist
in a new construction and adaptation of parts whereby the piston, wheel, con-
denser, and air pump are inade to form part of and to revolve with the main
axis, to which an uniform rotatory motion is given; also in a new construc-
tion of piston, in which, by means of certain movable parts and a screw, the
packing of the piston may be pressed outwards, so as to compensate by expan-
sion of size for the wearing of surface; also in a new construction of slides
dividing the piston chamber into compartments, narrow projections, or legs,
being annexed to the said slides in such a way that when they are withdrawn
to give passage to the piston, the projections or legs fill up the grooves in which
the slides moved, so as to prevent any cavity or rough edge, and render the
surface flush:
FURTHERMORE KNOW YE, that my improvements in high-pressure steam
engines do consist as well in the said new construction of pistons as in a new
construction and adaptation of steam channels or passages, piston wheels, piston
chambers, and falls and rocketts, by means whereof two or more pairs of
pistons are made to move alternately, and by. their successively alternate
impulses to communicate a continued and uniform rotatory motion to the shaft
or axis of the engine; also in a new construction and adaption of parts, whereby
the pistons are made to move over surfaces uninterrupted by any irregularity:
.
AND KNOW YE, FURTHERMORE, that my said improvements in boilers
do consist in the use of sheet iron formed into a series of cylinders, having their
odges flanged or shouldered alternately, inwards and outwards; these cylinders
being placed together with the inner flange or shoulders of one overlapping and
enclosing the outer flange or shoulders of the next, form one continued cylinder;
and are brazed at the joints so as to be secure, independent of the aid of
rivets. In order that the exterior circumference of any one may embrace
with the utmost firmness the interior edge of the next in succession, it is to be
made hot while the latter is introduced, so that in cooling its contraction may
answer that effect.
.
Whereas in the course of the explanatory descriptions and references to the
annexed Drawings, sundry parts and pieces of mechanism may be set forth as
the purposes of explanation require, which are not original in their nature nor

page_text: constitute any part of my Invention, but are meerly collateral, thereto and
entering expediently into the construction. Know ye, therefore, that I lay no
claim to any such parts, but only to those which are manifestly and essentially
conducive to the several objects herein above enumerated.
Reference to Drawing 1, representing the condensing engine hereunto
annexed, Figures 1 and 4. A, B, the steam pipe leading in the ordinary
manner from the boiler, but turned and fitted at its end B to receive a, a,
the stuffing box, by which the engine is enabled to obtain free and secure
access of steam, without affecting the stationary part B with its rotatory action;
C, D, E, the hollow axis to which all the revolving parts are attached, being
the general centre of rotation, and consisting of sundry parts, projections, and
channels herein-after specified; b, b, b, b; one of these projections, containing
F, F, the steam channels, and G, G; the eduction passages. This projection is
cylindrical in its form, and from its carrying H, H, the pistons, is called the
piston wheel; I, I, à circular passage called the piston chamber, and corre-
sponding in its functions with the cylinder of ordinary engines. The ends and
the exterior boundary are fixed; the piston wheel constitutes the inner boundary,
and is consequently movable, but so formed and fitted by turning and other-
wise, as to preclude all escape of steam at its junction. The pistons which revolve
in this chamber are attached by c, c, keys, to that part of the piston wheel imme-
diately situated between the steam and eduction passages, so as to receive a
continued pressure and vacuum on their opposite surfaces. The communication
between these two mediums being intercepted by K, K, slides, which divide the
piston chamber into compartments, and officiate as valves. From the principle
of this operation it is evident that the number of these compartments is quite
arbitrary and merely determinable by that of the piston and slides; the present
arrangement is with three as an expedient number. These slides being plates
of brass or other metal enter at long apertures, protected by d, d, stuffing
boxes, and move in grooves cut in the ends of the piston chamber to receive
them, which grooves, upon the slides being withdrawn, are occupied and ren-
dered flush and even for the passage of the pistons by e, e, narrow projections
or legs belonging to the slides f,f, packing rings, interposed between the ends
of the piston chamber and the piston wheel for purposes of lightness and
security; these also serve to receive the above last legs at the closing of the
slide, having cavities for that purpose. They are furnished with g, g, springs and
screws to regulate their pressure against the piston wheel. Each of the slides.
is perforated through the side; the perforation is furnished with a shutter 4,
and the shutter with a long handle, which projects to the outside of the engine.
By means of this shutter a communication between the adjacent compartments

page_text: into which the cylinders is divided by the slides may be opened or shut at
pleasure. When the communication is open the steam has access to every
part of the engine, and the operation of blowing is performed, and shutting
the communication and admitting the injection in the usual manner the engine
is started. L, L, a wheel supporting M, an eccentric ring, and N, a scroll.
The former of these, by passing through a notch in the slides, communicates
to them the necessary action of opening and shutting, and by the intervention
of h, a spring roller, causes them while shut to press uniformly against the
surface of the piston wheel so as to be air-tight at the line of contact. The
latter serves to work O, the hot liquor pump, by i, a notch at the extremity
of its rod P; the condenser being simply an enlargement of the axis, and
receiving its jet by J, a small pipes which communicates with a cistern sup-
plied by a cold liquor pump not shewn in the Drawing. k, k, k, k, the air
pump, so called from the indentity of its functions with that of ordinary air
pumps, although the present is a mere repetition of the machine above de-
scribed for the adaptation of steam only, differing inasmuch as the pistons put
in motion by the main axis become the active instead of the passive agents,
communicating their action to instead of receiving it from the surrounding
medium. The ingress of matter to the air pump is by the hollow axis leading
from the condenser, and its egress by Q, Q, pipes which disgorge themselves
into R, the lot well. This well has S its waste pipe, as usual; T, T, a circular
passage supplied by U, a pipe from the well; it has a cover ground on air-
tight, and preserved so by its gravity, or when vertically situated, by a spring,
which cover fitting the heel of the main axis partakes of its rotation by means
of a feather; it is from this cover that the smaller pipe issues before men-
tioned (J) as entering the condenser W, W, W, W. The exterior casing
which supports the whole rotatory mass by 1, 1, the brasses, one of which
resting on a carriage which is secured only by bolts, access is at any time
attainable to the interior of the piston chamber X, X. The wheel which
carries the eccentric ring of the air pump may be furnished with cogs to act
on the machinery such as it may happen to be, as, for instance, Y the bevel
wheel, and Z its shaft, or the necessary action may be communicated by an
elongation of the main axis, or otherwise, as most expedient. Figure 2 repre-
sents the same view of which Figure 1 is the section. Figure 3 shews the
whole, enclosed in the exterior casing, which is laid open in Figure 2. Figure 5,
a horizontal section through the air pump, &c. Figure 6 a plan of the whole.
Reference to Drawing 2, representing the high-pressure engine hereunto
annexed, Figures 1, 2, 3, 6, 7, 11, 12, 13, 14, 15. A, A, the boiler, in
which are contained the whole works of the steam engine; B, the fireplace;

page_text: C, the flue, which is intersected at intervals by sundry small vertical tubes;.
these tubes, being open at each end, operate to produce a constant current.
upwards by rarifying the water as it enters and converting it to steam; D, D,
a circular passage, called the piston chamber, corresponding in its functions to
the cylinder of ordinary construction, and similar to the piston chamber described
in the condensing engine; E, E, another piston chamber, only differing from
the former in size, which may be in the proportion of about four to one.
Now, to trace the operation of the engine, with a view of explaining its:
various parts, suppose F, the throttle cock, to stand as represented, the steam.
enters the passage b, and passing through the channel c in the main axis, issues
into the valve slide d, d. This slide, moving upon a pivot at e, serves to effect all:
the requisite changes of communication by means of its several passages f,f,fiƒ‹ƒ,
which are duly adapted in the manner of ordinary slide valves to corre-
sponding passages in the seat (Fig. 11), which constitutes the face of the piston
wheel (, ). The steam now proceeds through its proper communication in
the slide to one of the perforations g through the axis, and passing longitudinally:
arrives at the steam channels in the smaller piston wheel which is attached to
the axis, from thence it escapes at h (Fig. 13) into the smaller piston
chambers D, D; "here it performs its object by propelling the pistons D, D,
through a portion of a circle, after which, the communication being changed
by the shifting of the slide d, d, occasioned by the action of a tappet on the
projections i, i, the steami rushes back through the channels by which it
entered, passes through the axis to the larger piston wheel which is attached to
the axis, and issues through the passages r, r, r, r, into the larger piston
chamber E, E, where, from its expansive force, unaided by any supply from
the boiler, the pistons E, E, are propelled through a portion of a circle, after
which the steam, in its exhausted state, is suffered to escape through k, k,
in the axis into the atmosphere at I. By repetition of this process an alternate
motion is obtained of the two piston wheels: first of the smaller, then of the
larger one; and by the introduction of another pair of pistons to each
chamber, alternating their motion with the former, a continued action is
kept up within both chambers, by one pair of pistons moving while the
other is at rest. This alternate motion of the piston is made to produce
a regular rotation of the fly shaft by means of palls and rocketts, which are so
interposed as to prevent or correct every retrogade motion, and to communi-
cate every motion in the right direction to the shaft. Having thus far ex-
plained the nature of its operation, less difficulty may occur in comprehending
the remainder of the reference. E, E, are pistons of the larger piston chambers,
and D, D, pistons of the smaller one. These are attached respectively to their