AN IMPROVED STEAM ENGINE, CERTAIN PARTS OF WHICH IMPROVED STEAM ENGINE ARE APPLICABLE TO STEAM ENGINES ON THE ORDINARY CON- STRUCTION
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MATTHEW
PUNSHON, of Norfolk Street, Blackwall, in the County of Middlesex, Engineer,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victória, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-second day of June, One thousand eight hundred and
thirty-nine, did, for Herself, Her heirs and successors, give and grant unto
me, the said Matthew Punshon, my exors, admors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Matthew
Punshon, my exors, admors, and assigns, and such others as I, the said
Matthew Punshon, my exors, admors, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term of years therein mentioned, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, and also in all Her Majesty's Colonies and Plantations abroad, my
Invention of "AN IMPROVED STEAM ENGINE, CERTAIN PARTS OF WHICH IMPROVED
STEAM ENGINE ARE APPLICABLE TO STEAM ENGINES ON THE ORDINARY CON-
STRUCTION;" in which said Letters Patent is contained a proviso that I, the
said Matthew Punshon, should, by an instrument in writing under my hand
and seal, particularly describe the nature of my said Invention; and the
manner in which the same is to be performed, and cause the same 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Matthew Punshon, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully set forth in
the Drawings hereunto annexed, and in the following description thereof (that
is to say) :-
The Drawing Number I., Figure 1, exhibits a side view of my said improved
steam engine, as applied for marine purposes, next the midship line of the
vessel, and Figure 2 a longitudinal section of the same.
The Drawing Number II., Figure 3, presents a side view of my steam
engine next the ship's side, and Figure 4 is a front view.
The Drawing Number III., Figure 5, is a plan of the top part of my engine;
Figure 6, a horizontal section through the line C, D, of the Figures 1, 2, 3,
and 4, (Drawings Number 1 and 2,) and Figure 7 is a horizontal section
through the lines E, F, also of the Figures 1, 2, 3, and 4; in each of these
Figures and Sheets of Drawings the same letters of reference refer to similar
parts. The Figures are drawn to the scale of one inch and a half to a foot,
and upon that scale they represent a marine engine of seventy horse power.
A, A, A, are the bearers or sleepers at the bottom of the vessel, forming the
foundation upon which the engine is to rest. B, B, is a hollow or tube girder
supporting the bearings in which the paddle wheel or crank shaft of the
engine turns. C, C, C, is the outer framing of the engine next the ship's side
supporting the girder B, and consequently the inner bearings of the paddle
wheel shafts. The framing C, C, C, is screwed or bolted down to the beams
or sleepers A, A, and also bolted fast to the hot-water cistern G, H, and in one
piece with this framing is cast one of the bearings for the oscillating cylinder
to work in. D is the bearing on the other side of the engine, that is to say,
next the midship, for the oscillating cylinder to work in on that side. It is
likewise bolted down to the beams or sleepers A, A. E, E, are two columns
which are bolted to the bearings or cylinder plumber block at the bottom, and
which supports and is bolted to the girder B. At the top of F is a cross tie
or binding piece which passes from the top of the columns E and girder B to
the hot-water cistern G, H. G is the condenser bolted down to the beams or
sleepers A, A, and connected to the framings C, C. H is the hot-water
cistern bolted to the condenser G, and attached at the top part to the framing C
and cross tie or binding piece F. J is the square eduction pipe from the
cylinder bearing to the condenser G. K is a tube of an elongated oval form
(which may be made of wrought iron or copper for the sake of lightness)
which supports, if necessary, a body of water on the head valve of the air
pump. L is the oscillating cylinder of the engine, which is moved backwards

page_text: and forwards by the motion of the crank, the same as in other oscillating
cylinder engines. M (Figure 2) is the piston of the engine. N is the piston
rod. O is the piston rod cap, which likewise forms the bearing and connection
to the crank pin. P, P, is the intermediate crank shaft with its four crank
arms and two crank pins, and can all be rivetted or fitted so as to form
one piece as far as the point at each end, where it couples with the paddle
wheel shaft. The piston is preserved in a direct line with the axis of the
cylinder by a new parallel motion effected in manner following: R, R, are four
strong radius levers, two on each side of the cylinder, which are so connected
together at the bottom end by the short joint rods S, S, that the arms of
one of these radius levers cannot approach to or recede from a line coinciding
with the axis of the cylinder without causing the other to approach or recede
with it. The cross shafts T, T, are jointed to the top ends of these radius
levers, and attached to the crank pins by the parallel bars V, V, and as one of
these shafts and the upper arms of the radius rods cannot recede from the piston
rod or approach it without taking the other part with it, it is consequently
clear that the piston rod must always move in a rectilineal direction let the
cylinder be in what part of its oscillation it may. It is not necessary that the
bars V, V, should take their leverage from the crank pin, for they can be con-
nected to the piston rod at any point thereof, if found convenient, and their
effects, as regards a parallel motion, will be the same. W (Figure 6) is a
shaft supported by and working in bearings forming part of or attached to the
cylinder, by which shaft the two back radius levers are keyed fast together;
this serves to give more stability to the motion. The two front radius levers
work in two pins X, X, which are screwed fast on to the cylinder flanges. (I
call the two levers next the nozel the front levers, and those next the air pump
the back levers.)
I shall now proceed to describe the means by which in my said improved
steam engine the air, bilge, and feed pumps, or air, hot and cold water, pumps,
are worked, which means are also wholly new.
In the Drawings, Numbers I., II., and III., Y, Y, are levers screwed fast
to the cylinder, and connected by side rods with the air, bilge, and feed pumps
through the medium of the cross head Z, nearly in the same manner as in beam
engines. The levers Y, Y, partaking of the oscillating motion of the cylinder,
that motion serves to work the pumps connected with the cross head Z, and in
this method of working the pumps, nainely, by means of the oscillating motion
of the cylinder, consists the novelty of this part of my said improved engine.
a is the air pump barrel screwed fast to the condenser and hot-water cistern
G, H; (Figures 2 and 3) is the air bucket; c is the foot or bottom valve
b

page_text: of the air pump; .d is the head or delivery valve of the air pump; e is: the air
pump rod connected at the top to the cross head Z; fis the feed-pump barrel
placed next the midships part of the engine and standing on the bracket f,
cast in one piece with the condenser; g is the feed-pump' plunger, attached to
the cross head Z:by a key (k), worked in a straight line by the side guides l, l.
When the boiler, having water enough, does not require to be fed the key. k
is taken out, whereby the cross head Z works up and down the rod l, and
thereby presérves a rectilineal motion, but does not work the feed pump (m).
n is a piece of the feed pipe; o is the bilge pump, worked in the same manner
as the feed pump; p is the bottom valve box; q is the top valve box to
deliver the bilge water into the hot-water cistern.
"
' I shall next proceed to describe a new method of working slide valves
expansively or with expansive steam, which I have employed in my said
improved steam engine, and which will be found of great utility where the
motion of the engine is required to be reversed, that is to say, where the steam
engine is required to be worked backwards as well as forwards, as in steam
boats; mining engines, locomotives, &c. In lifting engines, where the steam is
worked expansively, the means employed are generally spindle valves and hand
gear, but in marine engines the D packed slide, adjusted to be worked by the
eccentric, has almost universally superseded all other contrivances for the
purpose. The D slide is, however, attended with this great inconvenience,
that when the engine is required to be reversed the action of the eccentric is in
the opposite direction, to remedy which the engines used or first to be worked
backwards by hand, but now the eccentric is made loose. In some of the
steam carriages there are two eccentrices employed to work one slide, keyed
on the crank shaft, so that one has the lead one way and the other the opposite.
Now, the method I employ consists in raising and depressing the bearings of
the Y shaft, and consequently the slide, as much as the lap of the slide or
expansion of the steam requires, and this I do by means of the pistons of the
cylinders, that is to say, the motion of the piston separately works the lap of
the slide, so that "the lead" of the engine, as it.is technically called, shall
always be in the right direction. In the Drawings, Numbers I., II., and III.,
7 (Figure 7) is a bolt that ties or connects the arms or levers Y, one end of
which bolt serves as the pin for a bell crank (s) to work on, which bell crank
gives motion to the levers which work the slide. The bell crank is held at
one end by the rod t, which is secured to the plumber block beneath, and is
placed so far from the centre of the cylinder bearing as just to give the right
length of motion to the slide. v is the rod gives motion to the levers of the
shaft (W or Y shaft) to move the slide. (This rod is usually called in other

page_text: engines the eccentric rod.) x is a double-armed lever keyed fast on to one end
of the Y shaft. Each arm of this lever, that is to say, the upper and lower
arms, have joint pins to receive the notch of the rod v, (see Figure: 4,) so that
when the rod. is taken off or out of the upper arm joint pin (where it
5 is represented to be in the' Drawing), and put in or upon the lower arm joint
pin, it will work the slide valve the contrary way to that in which they were
previously moving, and consequently reverse the motion of the engine. y, y,
are the arms of the Y shaft, which work the side rods z, z, which are connected
at one end to the arms of the Y.shaft, and at the other to the slide cross head:
a, b, is the slide rod attached to the slide at the bottom end, and to the cross
head at the top, so that when the. Y shaft works the cross head upwards and
downwards it gives motion to the slide 7. In the Drawings, hereto annexed
I have represented the slide as the slide usually called the D slide, but
the motion to cut off the steam at any desired portion of the spoke of
the piston is equally applicable to all descriptions of slides. f,f, are moving
brackets whereon the bearings. of the y. shaft work, and by which the y
shaft is raised and lowered, and consequently the D slide, by its being
attached to the moving shaft of the parallel motion V by the rods 9,9, which
raise and depress the brackets f,f, as much as the last of 'the' slide requires;
h is the first part of the main steam pipe, which contains the two throttle
valves; J is the steam pipe that carries the steam into the bearing or cross
axis of the cylinder next the midships, which steam pipe is continued on to
the cylinder bottom; k is the gland forming the steam stuffing box of the
main bearing of the cross arm of the cylinder; 1 is the cylinder bottom into
which the steam enters before it goes into the nozel or slide; m is the nozel or
slide casing; n (Figure 2) is the upper steam port from the nozel into the
cylinder; 0, Figure 2, is the lower steam passage leading from the nozel into
the cylinder. (The red dotted line in the nozel represents the position of the
slide when the piston is at the top of the cylinder, and when the crank is on its
top centres the slide will then be turned downwards by the operation of the
parallel motion by means of the moving brackets f, on which the Y shaft
works; and thus the lap of the slide closes the opening to the cylinder and cuts
off the steam, and allows the remainder of the stroke of the piston to be
produced by the expansion of steam in the cylinder; (p is the blow cock to let
the steam pass through into the condenser). It may appear at first that the
piston slide motion to work the expansion of steam ought to be reversed, as
well as the eccentric slide motion is, but an attentive examination of the
Drawings will show that all that is necessary to reverse the motion of the engine
is to change the position of the eccentric-lever. It will be further observed,

page_text: that in Figure 2 that the valve inside of the blow cock acts in a contrary way
to that in which it does in other engines where the D slide is used, because the
induction and eduction passages in the passages or channels in this nozel and
slide are the reverse of those in most other engines, for in other engines the
steam enters the middle of the nozel; and whereas in my improved engine the
eduction takes place at the middle of the nozel, and the steam passes through
the cross axis of the cylinder next the ship's side into the eduction pipe, and so
into the condenser. In order to keep the bearing joint of the cross axis of
the cylinder that leads into the eduction pipe J air-tight, with as little friction
as possible, I double pack the said joint, that is, I leave an opening in the middle
of the packing, and let water into this said opening, so that if the packing is
not air-tight a little water only will be drawn into the condenser, which is
a matter of no consequence as it will only facilitate the condensation of the
steam. The method of making this joint will be seen by the dotted lines
inside of the eduction pipe in Figure 7. The hole by which the water is to
be let in at top is also shewn in Figure 7. The water can either be let in
by a small pipe, or by a head of water. 7 is a screw worked by a handle, and
connected to the valve inside of the blow cock p, by the unscrewing or
screwing of which the valve can be opened or shut, and in order to facilitate
its shutting I have introduced spiral springs to force it up (see Figure 2);
r is the injection slide cock; the injection water passes right through the
eduction pipe and into the condenser; 8, s, are the levers and handle to work
the injection cock.
The Sheet of Drawings, No. 4, Figures 8 and 9, represent another
description of framing for my said improved engine, in which the supporting
columns are at the front instead of at the side of the cylinder, by which
of construction the cylinder may be removed with greater facility from its
bearings when it is found necessary so to do than in the previously described
mode of constructing the framing.
And having now fully described the nature of my said Invention, and the
manner in which the same is to be performed, I declare that I do not claim any
of the parts of the improved steam engine herein-before described which are
old and known separately, nor otherwise than and in so far as the same are in
the said engine newly combined and arranged.
And I declare that what I claim as of my Invention is, the improved steam
engine herein-before described, composed of parts and arrangements of parts,
some of which are old, but which in its entirety is different from any other
steam engine heretofore constructed.
And I declare that the parts and arrangements of parts which I claim as

page_text: being in themselves new are, first, the peculiar parallel motion; second,
the method of working the air, bilge, and feed pumps by the oscillation of the
cylinder, or in connection with the said parallel motion; and, third, the method
of working slide valves expansively, or with expansive steam, whereby the
engine can be worked either forwards or backwards with great facility, all as
herein-before particularly described and represented in the Drawings hereunto
annexed.
And I declare that the parts of my said improved steam engine which
I consider to be applicable to steam engines on the ordinary construction are,
the parallel motion, which may be adapted to fixed as well as oscillating
cylinders, and the method of working the side valves, which may be adopted
with advantage in all cases where engines are worked expansively and a
reverse motion required.
And such my Invention being to the best of my knowledge and belief
entirely new and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, Her Dominion
of Wales, and Town of Berwick-upon-Tweed; and also in all Her said
Majesty's Colonies and Plantations abroad, I do hereby declare this to be
my said Specification of the same, and that I do verily believe this my
Specification doth comply in all respects fully and without reserve or disguise
with the proviso in the said herein-before in part recited Letters Patent
contained, wherefore I hereby claim to maintain exclusive right and privilege
to my said Invention.
In witness whereof, I, the said Matthew Punshon, have hereunto set
my hand and seal, this Twenty-third day of September, One thousand
eight hundred and thirty-nine