CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SAMUEL HENSON, formerly of Allen Street, Lambeth, in the County of Surrey,
and now of New City Chambers, in the City of London, Engineer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date
at London, the Sixteenth day of February, in the fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Samuel Henson, Her especial licence, full power, sole privilege and
authority, that I, the said William Samuel Henson, my executors, admini-
strators, and assigns, and such others as I, the said William Samuel Henson,
my executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
England, the Town of Berwick-upon-Tweed, and Her Majesty's Colonies
abroad, my Invention of " CERTAIN IMPROVEMENTS IN STEAM ENGINES;" in which
said Letters Patent is contained a proviso obliging me, the said William
Samuel Henson, by an instrument in writing under my hand and seal, par-
ticularly to describe and ascertain the nature of the said Invention, and in
what manner the same is to be performed, and to cause the same to be enrolled
at London, within six calendar months next and immediately after the date of
the said in part recited Letters Patent, as in by the same, reference being
thereunto had, will more fully and at large appear.
NOW KNOW YE, that in pursuance of the said proviso, I, William
Samuel Henson, do hereby declare the nature of my said Invention, and the

page_text: manner in which the same is to be performed, are fully ascertained in and
by the following statement thereof, reference being had to the Drawings here-
unto annexed, and to the figures and letters marked thereon, that is to say:
The first part of my Invention is applicable to steam engines in which high-
pressure steam is used, and consists in permitting the escape from the cylinder,
or from the steam passages between the cylinder and the condenser, during a
very short interval of time near the termination of each single stroke of the
engine, of so much steam as shall leave the remainder in the cylinder but
little above.atmospheric pressure, and condensing that remainder by the means
ordinarily used in condensing engines.
The second part of my Invention consists in clearing the condenser or con-
densers of steam engines in which high-pressure steam is used, by the appli-
cation to that purpose of part of the force by which steam used therein exceeds
the pressure of the atmosphere, such condenser or condensers being at intervals
immersed in water..
The third part of my Invention consists in the application of a governor to
the safety valve of steam-engine boilers, by which it is raised when the engine
is at rest.
DESCRIPTION OF THE DRAWINGS.
Figures 1, 2, and 3 are designed to shew the mode in which I prefer to carry
into effect the said first part of my Invention; and of these Fig. 1 represents a
front view of a steam engine cylinder, with apparatus attached for working tho
common valves as well as that required for the peculiar purposes of this Inven-
tion. Fig. 2 is a side view, and Fig. 3 is a horizontal plan of the same.
Fig. 4 exhibits separately the cams which are shewn in connection with other
parts by the Figures 1, 2, and 3. The same letters of referenco denote the
same parts throughout these Figures. A, is the cylinder of the steam engine;
B, the piston, and 6 the piston rod; C, the steam pipe leading from the boiler;
D, the induction pipe; E, the eduction pipe, understood to be continued as
usual to the condenser; d¹ and d are the induction valves; and are the
eduction valves; F and F are the chambers through which the steam pipes
communicate with the cylinder, and respecting which I would remark that I
prefer that the openings from them into the cylinder, and the chambers them-
selves, should be larger than usual; G₁and G are the escape valves; they cover
corresponding openings in the chambers F and F, by which part of the steam
escapes into the atmosphere, according to the design of my Invention;
g' and g² are springs which assist the return of the valves G¹ and G³ to their
seats..

page_text: Having now indicated the principal parts of the apparatus I prefer to
employ, I will point out their movements, and in so doing I shall always
suppose that the steam used is considerably above atmospheric pressure.
During the greater part of the downward stroke of the piston B the upper
escape valve G¹ is held firmly to its seat by the action of parts, to be described
hereafter. When the piston has nearly reached the end of its stroke tho
pressure is removed from the valve G', on which the excess of the pressure of
the steam in the cylinder over that of the atmosphere opens the valve, and so
much steam escapes as that the pressure of the remainder is equal to that of
the atmosphere together with the force of the spring g', the valve G³ then closes,
aud the eduction valve c¹ is opened, which admits the remaining steam to the
condenser, and a vacuum is formed in the cylinder in the ordinary manner of
condensing engines. In the upward stroke the corresponding parts perform
similar functions, as will readily be understood. By this means the pressure
of the atmosphere is removed from the side of the piston opposite to that on
which the steam acts, which had not ordinarily been done in steam engines
worked with high-pressure steam. The movements of the valves above
described are effected in the following manner by the parts 1 now describe:-
h is a shaft connected by the wheels h¹, h³, or in any other convenient
manner, with the main shaft of the engine, so as to make equal revolutions
with it; i, i, are the bearings in which the shaft h turns; j, j, bars of the frame
supporting the said bearings, and which are themselves secured by one
end to the cylinder A, and by the other to the upright or standard k, k;
k, k, is an upright or standard affixed near its lower end to the base plate of
the engine; and is a stay, by which the upper end of k, k is firmly held in
its place; m is a bar secured to the steam chests F1, F2, for supporting the
centres of the levers o¹, 0%; H₁ and H3 are two levers whose contres are in
one line, and are supported by the upright ; H', the shorter of these, carries
a truck or roller, which applies to the cam No. 3; H³, the lower lever, carries
a similar truck, which applies to the cam No. 2; n', n', is a rod which passes
through stuffing boxes in the valve chests F1, F2, and is attached to the
valves e¹ and da, being itself actuated by the lengthened extremity of the lever
H' pressing against the collar formed on the rod n³; n' is a rod attached to the
lever H, and actuating the levers n³, n³, whose centres are in the upright K,
and whose extremities move the valves d¹, e", by their stems moving through
stuffing boxes in the stem chests F¹, F³, as shewn in the Drawing. The moving
apparatus for actuating the valves, which I have so far described, only effects
such opening and closing of the valves as in common to and required by all
condensing engines. The shape of the cams No. 2 and No. 3, necessary for

page_text: that purpose, is shewn by Figure 4. The cams 2 and 3 are made fast on the
tube 4, which is put over and can turn on the shaft h, and on which is the
journal which carries the front end of the compound shaft. The plate 5 is
also secured on the same tube, but is outside of the journal. Beyond it projects
the shaft h, on which is fastened the cross bar 6, carrying at each end the clicks
71 and 7. In the edge of the plate 5 is formed a long notch or fall, as shewn
in the Figure, and on its face is fastened the stud and handle 8. When, as in
the Figure, the cams are intended to turn with their upper edges moving from
right to left, the stud 8 is brought against that part of the cross bar which
appears lowermost in the position of the parts as drawn, and the click 7' is
forced by its spring into the fall or notch, so as to abut against one end of it.
When it is desired that the engine shall turn the other way, the cams will be
brought into the right relative position by releasing the click 71, and turning
round the plate 5 and tube 4, with the cams it carries, until the stud 8 comes
against the other part of the cross bar 6, and the click 7 abuts against the
other end of the fall in the plate 5. 01, 0%, are levers carrying trucks which apply
the cam No. 1 respectively at the opposite ends of its vertical diameter, and by
which through other parts the escape valves G' and G2 are at proper times
confined and set at liberty. They are connected with each other by a spring
0. p'p', are connecting rods. 9, 9, are levers whose centres are supported
by the upright, and which are connected by the rods p', p², with the levers
o', o, respectively as shewn in the Drawing. 2, are levers jointed by one
end to g' and ', and each carrying at its other end a strong pin or stud which
enters tho slot in the stem of S' or S² of its respective escape valve G' or G².
t, t, and u', u', are the bearings in which the stems S', S³ of the escape
valves slide. It will be readily scen that when, as in the position represented
in the Drawing, the smaller part of the cam No. 1 comes to the truck or lever
o (which should be when the piston is near the bottom of the cylinder) that
lever will be depressed, and by means of the rod p' will bring down the joint
by which the levers q' and r¹ are attached to each other, and thus withdraw
the stud on the lever r' from its pressure against the end of the slot in the
stem S¹ of the valve G'; the valve, being thus released, gives way to the
pressure of the steam in the cylinder, and permits the escape of part of it as
above described. During this time the larger part of the cam No. 1 holds
down the lever o, by which the rod p has been made to depress the joint of
the levers and 72, so as to bring them nearly into a continued straight line,
and by this means the stud in the lever is strongly pressed against the end
of the slot in the valvo stem S, and the valve G 2 is firmly held in its place
against the pressure of the steam in the cylinder. A further rotation of the

page_text: cam holds both valves close, and at the end of a semi-revolution the upper
valve is held close and the lower one set at liberty, which the action of the
engine, as before explained, requires. The spring os raises the lower oº, when
permitted to do so by the hollow in the cam No. 1.
I will now recapitulate briefly the course of the valve movements, and the
way in which they are effected. Beginning with the piston near the bottom
of the cylinder, as shewn in the Drawing, the escape valve G' is first
released by the truck on the lever O' falling into the hollow of the cam No. 1,
and the excess of steam escapes into the atmosphere at once, or along such
pipe as may be used to conduct it; an instant after, and nearly at the moment
the piston reaches the very extremity of the stroke, the eduction valve e' and
the induction valve d are raised by the rise on the cam No. 2 operating on
the lever H; about the same time the escape valve G₁ has closed by the
pressure of the atmosphere and the spring g', and is soon hed fast again by
the cam No. 1. This state of things continues during almost the whole time
of the up-stroke. When the piston has nearly reached the top of the stroke,
the escape valve G is released by the hollow in the cam No. 1 then coming
to the truck on lever 02. When the piston comes to the end of the
up-stroke, the rise on the cam No. 3 raises the induction valves d and the
eduction valve e², the valves e¹ and d³ having been just closed by the fall in
the cam No. 2, and the escape valve G having also closed, and being held
fast by the cam No. 1. No further change takes place until the piston arrives
near to the bottom of the cylinder, when the series of changes again com-
mences. I wish it to be understood that I do not confine my Invention to
the arrangement above described, since many different modes of effecting the
same object may readily be devised, and such modes may consist of different
kinds of valves or different combinations of them, or different modes of weigh-
ing, confining, or actuating them, or of a different number or position of
openings into the cylinder, or of other varieties of parts or operations, some of
which may be more advantageous in some cases, and others in other cases, and
the propriety of using which can only be judged of on the application of my
Invention to each individual case. But the arrangement of parts which I have
now described, while it clearly shews the nature of my Invention, is; I believe,
most likely to be generally useful.
I will now describe the second part of my Invention. Figure 5 represents
a side view, and Figure 6 a front view, of the cylinder of a steam engine, with
the condensers, condenser cisterns, reservoir, and valve apparatus attached.
In Figure 5 all the parts cut by the perpendicular dotted lines 1, 2, and 3, 4,
in Figure 6, are shewn in section, and the rods cut by the horizontal line 2, 3,

page_text: are discontinued. Figure 7 represents the several cams using for opening
the valves. In each of these Figures the same letters indicate the same parts.
A is the cylinder; B, the piston, and b, the piston rod; C, the steam pipo
leading from the boiler; D, the induction pipe, and E, the eduction pipe;
d¹ and d, the induction valves; e¹ and c, the eduction valves; F¹ and F, the
chest between the valves; G¹and G2 are the condensers; H' and H2, the con-
denser cisterns; I, is the cold water reservoir, kept at a proper height by
any convenient waste pipe; J, the supply pipe; g¹ and g³ are valves closing
the condensers at the top.
Having thus indicated the principal parts of the apparatus, I will point out
their general working and effect, and in so doing I shall suppose, as before,
that steam considerably above atmospheric pressure is always employed. On the
near approach of the piston to the end of its down stroke, as shewn in the
Drawing, the valve g', is lifted, by which the communication is opened between
the cylinder and the condenser G¹, which condenser at that time contains
water, which is the product of the steam used in a previous stroke, together
with that of the injection, if any, used in condensing it. The steam, by its
excess of force over atmospheric pressure, drives out the water in the con-
denser G', through the valve o¹, in the bottom of it; after which the greater
part of the excess of steam escapes also by the same valve. By the time
this escape of steam has reduced the remainder nearly to atmospheric pres-
sure the valve g¹ is closed and g³ is opened, so as to admit the remaining
steam to be condensed in condenser G2 in the ordinary way.
In like manner,
when the piston has arrived nearly at the top of its stroke, the extra steam
(meaning by that term so much of the steam, or nearly, as occasions that
employed in the engine to be above atmospheric pressure,) is admitted to the
condenser G, and employed there to drive out the water resulting from the
condensation of the previous stroke, and the remainder is admitted to and
condensed in the condenser G, and so on alternately; but in order that the
extra steam while employed in clearing the condenser may not be condensed
so rapidly as to prevent it from producing that effect, that condenser is not at
that time immersed in water, but when in the succeeding stroke the same
condenser is employed in condensing the reduced or remaining steam for the
production of a vacuum, its cistern H is filled from the adjoining reservoir I.
To favor the same operations the condensers are made as thin as their size
and the pressure of the steam employed will admit.
I will now describe the parts by which I prefer to effect the necessary move-
ments of the apparatus. A frame is attached to the cylinder and base plate of
the engine, which is very similar to that shewn in the Figures 1, 2, and 3,

page_text: relating to the first part of my Invention, but adapted where necessary to the
parts about to be described, of which frame, however, in Figures 5 and 6,
there are shewn only the parts k, k, and j, j, the rest being removed for the
sake of clearness. / is a shaft turning in bearings on the frame pieces j,j,
and connected by the wheels ' and h, or in any other convenient manner,
with the main shaft of the engine, and making equal revolutions with it. The
cams on this shaft move the several valves through the intervention of levers,
which all have their centres in an horizontal line, of which one end is at m.
Each of these levers carry a truck, which applies to the edge surface of its
respective cam, and to these levers are attached the rods by which the valves
are immediately moved. All which is clearly shewn in the Drawing. The cams
a and b are employed in moving the ordinary induction and eduction valves of
the engine, as shewn before in the description of the first part of my Invention,
but their respective levers are also used to open, by the rods Z' and Z³,
the valves and as of the condenser jets y¹ and y³, of which only one
of each is shewn in Figure 6, the other lying directly behind them. The
cams c and d open the condenser valves g' and g, by means of rods
w and w, which pass from the levers belonging to those cams through
stuffing boxes in the lid, which forms the upper side of the horizontal part of
the eduction pipe E. The cams and regulate the admission and exit of
the cold water to the condenser cisterns Hand H³; their levers operate on the
rods which respectively pass from them through the guides affixed to the con-
denser cistern, as shewn in the Drawing, and the lower ends of which are
connected each by two long links to the arms u', u', us, u³, of the valves t¹, t¹,
,, by which the bottoms of the condenser cisterns H₁ and H³ are closed.
These valves extend across the condensers, and are made in other respects as
large as possible, in order to occasion, when opened, a rapid exit of the water;
they are mounted each on an axle turning in bearings on the outer end of
which is affixed the arm tor t. To the same cams and levers, e and f, are also
attached the rods S¹ and S, moving the valves 1 and 2, by which the cold
water in the reservoir I is alternately admitted into and excluded from the
condenser cisterns H' and H. The reservoir I is separated from the con-
denser cisterns by the vertical partition or diaphragm q, q, and these cisterns
are divided from each other by the vertical partition p, p, standing at right
angles to the former. In the partition q, q, are placed the valves r¹ and ³.
The injection pipes y¹ and y, each pass through both the partition q, q, and the
side of its respective condensers G¹ or G. The valves o' and o, in the bottoms
of the condensers G and G³, have springs on them, which, together with their
own weight, so regulate them as to admit of the pressure of the extra steam

page_text: forcing them open, although they are closed with sufficient firmness against
any other pressure within the condenser. Z, Z, Z, is a pipe or channel which
carries off the discharged contents of the condensers G¹ and G. Instead of
condensers with jets, surface condensation may be employed with no other
change of the form of the parts than such as is well known to be required by
use of that method. The order of the movements is as follows:-The piston
having nearly reached the bottom of the cylinder, the fall on the cam a closes
the induction valve d', and the eduction valve e, and at the same time opens
the injection jet y. The rise on the cam 6 opens the corresponding valves
d and e', and closes the injection jet y¹. Very soon after this the fall on the
cam c, by closing the valve g¹, cuts off the steam from the condenser G, into
which it had been flowing, and the rise on the cam d admits the remaining
steam into the condenser G, by raising the valve 9. As nearly as possible
at the same time the rise on the came closes the valves t¹, t, and opens the
valve r', so as to fill the condenser cistern H' from the reservoir I. On the
piston reaching a similar position at the upper end of the stroke, the cams of
cach pair reciprocally perform tho functions previously fulfilled by the
others, the rise which was then on a being now on 6, and the positions of
the induction c, eduction valves, and the ejection into the condenser, being
thereby reversed, the falls and rises before on c are now on d, by which valves
gis closed and g¹ opened. So also the cams c and now close the valves at
the bottom of the condenser cistern II', and admit the cold water into it from
the reservoir, opening at the same time the valves by which the cistern His
emptied, and so on reciprocally, according to the motion of the piston. To
adapt the cams, and thereby the motion of the valves, to a reverse motion of
the engines, it is only necessary to apply on the shaft h, or on one of the shafts
by which it is connected with the main shaft, any of the well-known con-
trivances for reversing the motion of wheel-work, so that although the fly
wheel may revolve in the direction contrary to its original one, the shaft h, and
the cams on it, shall continue to revolve in the same direction as before. Care,
however, must be taken that in re-engaging the wheels the right teeth come
together so that the motion of the valves shall correspond with the duc position
of the piston. I would have it understood that I do not confine my Invention
to the arrangement I have now described, since many variations may be
made without departing from the principle of it; but I prefer the arrange-
ments I have described, as the best in my judgment for carrying into effect
this part of my Invention.
The third part of my Invention is shewn in Figure 8, where B is part of a
steam engine boiler, S a safety valve, G a governor, moved by the steam

page_text: engine, and a lever, by which the governor G, when in motion, holds down
the safety valve S. The area of the safety valve is to be considerably smaller
than would admit the escape of the steam which the boiler is capable of
generating, but sufficient to occasion considerable ebullition, by which means
the water will by its own motion promote the equal distribution of the heat
through its substance, thus tending to reduce the danger of explosion. It will
readily be seen that while the engine, and, consequently, the governor, are at
rest, the valve will stand open, but while the engine is in motion the governor
will hold down the valve, and prevent its action. This valve and its apparatus
are additional to the ordinary safety valve, and are not by any means to be
used in substitution for it; but I sometimes apply a governor to the safety
valve itself, or to one of them, if there be more than one, and. I adjust it so
that by the collapse of the balls of the governor the safety valve shall be raised
a small distance from its seat; but I form the parts so that the valve may rise
by the force of the steam as much further as may be necessary to supply the
required area of escape.
Having thus described the above particulars, I confine my claims of Invention
to the following:-
1st, I claim the application to the cylinder of a steam engine using a con-
denser, or to the steam passages between the cylinder of a steam engine and
its condenser, of an apparatus or method of the nature herein firstly described,
so as to permit the escape from the cylinder, or from the steam passages
between the cylinder and the condenser, during a very short interval of time
near the termination of each single stroke of the engine, of so much steam as
shall leave the remainder of the steam in the cylinder but little above atmo-
spheric pressure, and condensing that remainder by the means ordinarily used
in condensing engines.
2d, I claim the clearing the condenser or condensers of steam engines in
which high-pressure steam is used, by the application to that purpose of part
of the force by which steam used by such engines exceeds the pressure of the
atmosphere, when combined with a condenser or condensers at intervals im-
mersed in water, as herein-before described.
3rd, I claim the application of a governor to the safety valve of steam engine
boilers, by which the safety valve is raised when the engine is at rest.
In witness whereof, I, the said William Samuel Henson, have hereunto
set my hand and seal, this Sixteenth day of August, in the year of our
Lord One thousand eight hundred and forty-one.
WILLIAM S.
(L.B.) HENSON.

page_text: AND BE IT REMEMBERED, that on the same Sixteenth day of August,
in the year above mentioned, the aforesaid William Samuel Henson came
before our Lady the Queen in Her Chancery, and acknowledged the Speci-
fication aforesaid, and all and every thing therein contained, in form above
written.
And also the Specification aforesaid was stamped according to the
tenor of the Statute in that case made and provided.