IMPROVE- MENTS IN VALVES FOR STEAM AND OTHER ENGINES
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
WHEELER, of Basingstoke, in the County of Hants, Ironmonger, send
greeting.
WHEREAS I did, by petition, humbly represent unto Her most Excellent
Majesty Queen Victoria, that in consequence of a communication from a
Foreigner residing abroad, I had become possessed of an Invention of "IMPROVE-
MENTS IN VALVES FOR STEAM AND OTHER ENGINES;" and Her said Majesty,
being willing to give encouragement to all arts and inventions that may be for
the public good, was graciously pleased, by Her Royal Letters Patent under
the Great Seal of the United Kingdom of Great Britain and Ireland, bearing
date at Westminster, the Third day of July (One thousand eight hundred and
forty-seven), in' the eleventh year of Her reign, for Herself, Her heirs and
successors, to give and grant unto me, the said Edmund Wheeler, my
executors, administrators, and assigns, Her special license, full power, sole
privilege and authority, that I or they, by myself or themselves, or by my or
their deputies, servants, or agents, or such others as I or they should agree
with, and no others, during the term of fourteen years from the date of the
said Letters Patent, should and lawfully might make, use, exercise, and vend
my said Invention within that part of Her said Majesty's Dominions called
England, Her Dominion of Wales, and Town of Berwick-upon-Tweed, in such
manner as to me, my executors, administrators, and assigns, shall seem meet,

page_text: and so that I or they shall enjoy the whole profit and advantage arising
by reason of the said Invention during the said term of fourteen years; and
whereas the said Letters Patent contain a proviso obliging me, the said
Edmund Wheeler, particularly to describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, and to cause the same to be enrolled in
Her Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said 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
Edmund Wheeler, do hereby declare that. the said Invention is described and
ascertained in manner following, and by the aid of the three Sheets of
Drawings hereunto annexed, that is to say:-
Part of the said improvements relates to valves for steam and other engines,
which valves are of the kind called slide valves, because the motion given to
the valve is of the nature of sliding motion, that is to say, the moving part
which is called the valve is applied in contact with, and slides against, a flat
surface, to which a corresponding flat surface of the valve itself is accurately
fitted, and the fitting surfaces are kept in such close contact that steam, water,
air, gas, or fluid, or liquid, cannot enter or pass between the fitting surfaces,
although the valve can be slided along the flat surface to which it is applied,
and, by so sliding, the valve uncovers and covers, certain apertures in the
said flat surface, so as to open and shut those apertures as may be required
for permitting or for stopping the passage of steam; water, air, gas, or fluid, or
liquid: It is essential that there shall always be a close contact of the fitting
surfaces of slide valves with the flat surfaces against which they slide, as afore-
said; and in one particular class of slide valves the pressure of the steam,
water, air, gas, or fluid, or liquid, is rendered operative for keeping the surface
of the slide valve in close contact with the said flat surface against which it is
applied, and against which it slides; but when the slide valve is of large
dimensions, and the pressure of the steam, water, air, gas, or fluid, or liquid, is
considerable, the force wherewith the slide valve is thereby pressed in contact
with
h the flat surface, to which it applies is much greater than is requisite for
ensuring so much closeness of contact of the fitting surfaces, as will prevent
the steam, water, air, gas, or fluid, or liquid, from entering between those
surfaces, and all the excess of pressure beyond what is requisite causes
unnecessary friction and resistance to the motion of the valve, and wearing
away of the fitting surfaces. Slide valves of the class or kind aforesaid are in

page_text: very general use in steam engines, without any contrivance for relieving the
slide valve from the excess of pressure; and there are also different contrivances
in use along with such valves, for so relieving them, as that the force where-
with the valve is pressed by action of the steam, water, air, gas, or fluid, or
5 liquid, towards the flat surface to which it applies, and against which it slides,
shall be no more force than is requisite for producing close contact and tight
fitting of the fitting surfaces. This part of the improvements consists of several
new combinations and arrangements of parts for relieving slide valves from the
aforesaid excess, of pressure; and I will now proceed to describe several slide
Ovalves which are constructed according to this part of the improvements,
and then, at the conclusion of this Specification, I will point out the par-
ticulars of new combination and arrangement of parts which I claim as new
Invention.
In Sheet I. of the Drawings hereunto annexed Figure 1 is a longitudinal
section, and Figure 2 a transverse section, of a slide valve, and of the flat
surface against which it applies and slides; also of the steam box or slide valve
casing wherein the slide valve is contained, the parts so represented in Figures
1 and 2 being parts of a steam engine. A, A; is the space within the said
steam box, into which steam is constantly supplied from the boiler through a
suitable steam pipe or steam passage, not represented in the Figures. B, B, is
the slide valve, and the straight line x, x, is the plane of the flat surface, against
which the valve applies with a corresponding flat surface of its own, so as to
fit with close contact one surface to the other. The slide valve B is hollow
within at y, and the steam within the steam box A, A, constantly presses the
slide valve B towards the flat surface x, x. There are three apertures,
t, v, w, in the flat surface a, a, against which the valve applies and slides,
in order that by its sliding motion it may cover or uncover the two aper-
tures t and w, as is required, the middle aperture being always open to
being the entrance
the hollow y, within the valve B, and that aperture
to the eduction pipe or passage K. Figure 1 represents the valve B, at the
midway of its sliding motion, in which position it covers over both the aper-
tures t and w, so as to close them both, and does not then allow any steam to
pass out of the steam box A, A into either of those apertures; but if the valve
is slided in one direction, for instance, towards W, then it will uncover and
open the aperture t, so as to admit steam from A, the steam box, to pass
through t, and the side passage or pipe T to enter into one end of the steam
cylinder wherein the moveable steam piston is fitted, and the piston is im-
pelled by that steam which is so admitted to enter one end of the cylinder
acting against one side of the said piston. The same motion of the slide valve B

page_text: will also uncover and open the other aperture w to the hollow y, within the
slide valve B, so as to connect the aperture w of the side pipe or passage W
with the middle aperture (and therefore with the eduction pipe or pas-
sage K), for permitting the escape of the steam from the opposite end of the
steam cylinder to that end thereof into which steam is at the same time
admitted from A, through t, T, as above mentioned; the steam which so escapes
through the eduction pipe or passage K being conveyed away thereby, and
by the continuation thereof, either to the open air in case of a non-condensing
high-pressure engine, or else to the condenser in case of a condensing engine;
and when the slide valve B is slided in a contrary direction, namely, towards T,
it will uncover and open the other aperture w of the side pipe or passage W,
so as to admit steam from A, through w and W, into the contrary end of the
steam cylinder to that end thereof into which (as above described) the steam
was before admitted, and thereby the piston will be impelled in a con-
trary direction. Also the same motion of the valve B will uncover the
aperture t to the hollow y within the slide valve B, so as to connect the aper-
ture t of the side pipe or passage T with the middle aperture v
(and there-
fore with the eduction pipe or passage K), for permitting the escape of the
steam from the opposite end of the steam cylinder to that end thereof into
which steam from A is at the same time admitted. I, Figure 1, is the valve
rod by which the slide valve B is moved or slided within its steam box A, by
suitable action, at the outside on the end of the rod I, which passes through a
stuffing box Z, at the end of the steam box A, in order to prevent escape
of steam from A to that outside. The sides of the steam box A are
marked m, m, and D, D, is the flat top thereof. Thus far is the usual and
well-known construction of slide valves for steam and other engines, and in
that construction the pressure of the steam within the box A, A, presses the
slide valve B towards the flat surface x, x, with which the corresponding flat
surface of the valve B is in contact; and the hollow y, within the valve B,
communicating always with the eduction v, K, the interior of the valve B is
only subjected to a pressure which, in a non-condensing steam engine, is but
very little greater than the pressure of the atmosphere, or in a condensing
steam engine the hollow y is kept exhausted of steam. In either case the
force of unbalanced pressure of the steam in A, which is operative to press
the valve B into close contact with the flat surface x, x, is much greater than
necessary for producing close fitting, and the excess of pressure only causes
unnecessary friction and resistance to the sliding motion of the slide valve B.
One part of the improvements for counteracting or counterbalancing such
unnecessary force of pressure on the slide valve B is, to apply an additional

page_text: sliding plate F to the slide valve B, and united or fastened so firmly thereto.by
means of the connecting piece E, that the said sliding plate F will be as nearly
as can be like one piece of metal with the slide valve B. The said connecting
piece E passes up through a large opening in the top plate D, which plate, as
already mentioned, forms the flat top of the steam box A, and the additional
sliding plate F has a border margin a, a, which applies to and slides against
the outer flat surface of the top plate D, with close fitting thereto, so that the
steam from the box A cannot escape between F and D, but the said: steam
having free access through the said large opening in the top plate D to act
against the inner surface of the additional sliding plate F, whilst the opposite
or outer surface of the same plate F is not subjected to any pressure of.steam;
or to no greater pressure than that of the atmosphere, the force wherewith the
steam presses against the said inner surface of F operates by means of the
connecting piece E, with a tendency to draw the slide valve B away from its
contact with the flat surface x, x, in opposition to the pressure wherewith
the steam in the box A is at the same time urging the slide valve B towards
the said surface x, x; and therefore, by that opposition, the said pressure
which urges the slide valve B towards the flat surface x, x, is in great part
counterbalanced or counteracted. The surface of the additional sliding plate
F is less than the surface of the slide valve B, because the width of the
plate F, as seen in Figure 2, is less than the width of the slide valve B,
although the length of the plate F is nearly the same as the length of the slide
valve B, as they appear in Figure 1; and, consequently, the force which the
steam exerts against the sliding plate F to draw the slide valve B away from
the flat surface x, x, is so much less than the force which the steam exerts
against the slide valve B for urging the valve towards the said flat surface x, x,
as to leave a sufficient part of the latter force unbalanced for ensuring the
requisite close contact of the slide valve B with its flat surface x, x, for
tight fitting, without any excess of pressure to cause unnecessary friction.
The valve rod I, which passes through the stuffing box Z in one end of the
steam box A, is connected with the slide valve B in the usual manner by
means of a square frame i, i, formed at one end of the rod I, and .sur-
rounding the slide valve B, suitably for communicating the requisite sliding
motion to the slide valve B within its steam box A, when such motion
is given to the rod. I from the outside, but without confining the slide.
valve B to preserve its contact with the flat surface x, x, in order that
in case of water getting by accident into the cylinder of the steam engine,
such water can make its escape by forcing the slide valve B away from its
usual contact with the flat surface a, a, being the same in that respect as

page_text: an ordinary slide valve, for the application of the improvement. thereto
does not confine the valve. The position of the valve rod I is as nearly as
can be intermediate between the two planes of the two fitting surfaces, videlicit,
the surface x, x, against which the slide valve B fits, and the surface of the
top pláte D, against which the margin a, a, of the additional sliding plate F
fits, those two surfaces x, x, and D, being made exactly parallel one to the
other, and the valve rod I is parallel to both, and the sliding motion which is
communicated by it to the slide valve B will be equally communicated to the
additional sliding plate F, which, as already stated, 'operates in every respect
in the same manner as if it were formed in the same piece of metal with the
slide valve B. The connecting piece E is represented to be in the same piece
of metal with the slide valve B, and it has strong pins (or tenons) projecting
from it, in order to pass through corresponding holes through the sliding
plate E; and by nuts G, screwed on the ends of the said pins (or by cross keys
put through holes across the said tenon's), the plate F becomes firmly united
to E, and consequently to the valve B. But note, the said connecting piece
E might be formed in the same piece of metal with the sliding plate F, and
pins projecting from the piece E might pass through corresponding holes in
the slide valve B, and have nuts screwed on the ends of those pins within the
hollow y'of the valve B. The sliding plate F is covered over by a covering
box S, the interior of which, in case of a non-condensing high-pressure engine,
must 'communicate freely with the open air by a small "opening (which may
have a cock to stop it), or by a pipe (which may have a stopcock), and which
pipe joins to the eduction pipe of the engine, or the said pipe may lead into
the chimney, so as in any case that all steam which may have leaked through
the fitting of F and D may make its escape into the open air or into the
condensor, without being confined within the covering box S; because, if so
confined, the steam would accumulate within the box S, so as to cause a pressure
of steam to act against the outer side of the sliding plate F; which is not
intended, for that outer side is, as already mentioned, not to be subjected to
any pressure of steam, or to no greater pressure than that of the atmosphere.
In case of a condensing steam engine, the covering box S may communicate
by ia pipe and stopcock with the eduction pipe, and thereby to the condenser,
so as to keep the space within the covering box S exhausted, and then the
outer side of 'the sliding plate F will not be subjected to any sensible pres-
sure of steam, for all steam which may leak through between the fitting surfaces
of D and F will pass away to the condenser, or instead of the said pipe and
cock, the requisite communication may be effected by. small holes drilled
through the connecting piece E, and through the centres of the screw.pins on

page_text: which the nuts G are screwed, so as to communicate constantly from the
interior of the covering box S to the hollow y within the slide valve B, which
hollow y, being always open to the eduction pipe or passage K, the
effect of the said small holes through the screw pins will be to form a
constant communication between the interior of the covering box S and the
eduction pipe or passage K. And note, although the Figures 1 and 2 repre-
sent the sliding motion of the slide, valve B to be in a horizontal direction, that
is only by way of example of a case in which the cylinder of the steam engine
is in a horizontal position, as in locomotive steam engines and some stationary
engines; but the improvement, and the manner of applying it to a like slide
valve, but which slides up and down in a vertical direction, will be nearly the
same; except that in the position of the parts represented in Figures 1 and 2,
the weight of the metal of the slide valve B, with the connecting piece E, and
additional slide plate F, will operate to keep the slide valve B in contact with
the flat surface x, x, independantly of any pressure of steam on the slide valve B;
and therefore the size of the surface of the additional sliding plate F may be
more nearly equal to the size of the surface of the slide valve B than would be
suitable for the case of the slide valve B sliding up and down in a vertical
direction, because the weight of the slide valve B, connecting piece E, and
sliding plate F, would then have no effect to urge the slide valve B in contact
with the flat surface x, x, and consequently the surface of the sliding plate F
should be less in proportion to the surface of the slide valve B than is repre-
sented in Figures 1 and 2. The aforesaid improvement, represented in Figures
1 and 2, is applicable to steam engines, of any kind in which slide valves are
used, and is most particularly applicable to locomotive steam engines, because,
at the same time that the improvement counteracts all needless excess of pres-
sure on the slide valve, the latter is left as much at liberty as usual (in like
slide valves of the ordinary.construction) to separate from its contact with the
flat surface x, x, in case of water getting, into the cylinder of the steam engine;
and for the same reason. the improvement is advantageous for marine steam
enginės. The improvement is also applicable to any other engines in which
slide valves are or may be used, such, for instance, as engines similarly con-
structed to steam engines, but impelled by compressed air instead of steam;
also water-pressure engines,,self-acting forcing pumps for water or other
liquids or fluids, blowing engines for air or for gas, exhausting air engines for
pneumatic railways, or other like purposes.
In Sheet II., Figure 1. is a longitudinal section, and Figure 2 a transverse
section, of another slide valve, constructed according to this part of the improve-
ments; and the same letters of reference being used as in Figures 1 and 2..

page_text: Sheet I., to denote the same or similar parts, the foregoing description will
serve to explain those parts in Figures 1 and 2, Sheet II., which are similar to
the corresponding parts in Figures 1 and 2, Sheet I., and it will, therefore, be
sufficient to describe those parts which are different. Instead of the additional
flat sliding plate F herein-before described, a circular piston F, Figures 1 and 2,
Sheet II., is firmly fastened to the slide valve B, by means of a strong
connecting piece E, which may be formed in the same piece of metal with
the slide valve B (or may be otherwise firmly fastened to the slide
valve B) so as to project out therefrom, and pass freely through a large
opening in the plate D, D; the piston F is securely fastened to the con-
necting piece E by a strong nut G; the piston F is fitted into a short
cylinder H, H, which is bored withinside, and the circumference of the
piston has metallic or other packing, to fit closely to the inside of the cylinder
H, H, so as to prevent escape of steam, although the piston can move freely
in the cylinder, which is open at both ends; but that end which is nearest to
the slide valve B is formed with an internal and an external flange a, a,
b, b, to form a broad margin, which is so closely fitted to the flat outer side of
the fixed plate D, D, as not to allow steam to pass between a, a, b, b, and
D, D, but so as to be capable of sliding against that flat surface of D, D, with
a sliding motion of the cylinder H, H, corresponding to that of the slide valve
B against the flat surface x, x; and in order to insure an exact correspondence
between the said sliding motions of the slide valve B and of the cylinder H, H;
an additional rod I' is fitted through a stuffing box at the end of the covering
box S, so as to give motion to the cylinder H, H, and the outer ends of
both the rods I and I¹ are connected together by a short cross head, which
is united to one rod X, and the requisite sliding motion being given thereto,
will be transmitted equally by the two rods I and I' to the slide valve B, and
to the cylinder H, H. The inner end of the said additional rod I¹ is con-
nected with the cylinder H, H, in any suitable manner, so as to have firm hold of
it. The inner end of the additional rod I¹ may for that purpose be formed with
a circular ring or hoop, to encompass the outside of the cylinder H, H in the
same manner as the square frame i, i, Figures 1 and 2, Sheet I., already
mentioned, at the end of the usual valve rod I, surrounds the slide valve B;
and the said additional rod I¹ may be prolonged, so as to take hold of the nut
G, or of the central part of the piston F, in order to give the same sliding
motion to the piston F as to the cylinder H, H, and to the slide valve B;
The flanges a, a, b, b, at the end of the cylinder H, H, must always keep in
close contact with the flat surface of the plate D, D, and the pressure of the
steam against the internal flange a, a, will have a tendency to produce such

page_text: contact; but in order to ensure the said contact, two or more flat blade springs
of steel (not represented in the Figures) are to be applied in any suitable
manner for urging the cylinder H, H, towards the plate D, D; for instance,
such springs may be disposed nearly diametrically across the cylinder H, H,
with their extremities lodged against the outer end of the cylinder H, H,
and with the middle parts of the lengths of those springs bearing against the
inside surface of the flat cover of the covering box S, in such manner as that
the elastic force of the said springs will be operative to urge the whole cylinder
H, H, towards the plate D, D, and during the sliding motion of the cylinder
the said middle parts of the lengths of the said springs, which bear against the
inside flat surface of the covering box S as aforesaid, will slide against that
inside with a sliding motion corresponding to that of the cylinder H, H,
against the plate D. The pressure of the steam against the surface of the
piston F, at the side thereof nearest to the slide valve B, will tend to draw the
slide valve B away from its contact with the flat surface x, x, in opposition to
the greater force wherewith the same steam is at the same time acting to
press the slide valve B towards the said surface x, x, because the area of the
piston F must be less than that of the slide valve B, in the same manner
as already fully explained in reference to Figures 1 and 2, Sheet I., the
action of the additional sliding plate F in those Figures being the same as
that of the piston F in Figure 1, Sheet II. And note, the flange. a, a, b, b, at
the end of the cylinder H, H, may be of a rectangular figure, where it applies
and fits against the surface of the plate D, if that form is preferred.
Figure 2, Sheet II., is a transverse section of only one half of the slide
valve and parts above described, but that Figure shews how a cock M may
be applied to permit the escape of waste steam from the interior of the
covering box S, either into the open air or into the eduction pipe or passage,
or the same cock may be used to prevent such escape as may be required.
L is a passage leading from the said interior of the covering box S to the
cock M, and L' is a continuation of the same passage from the cock M, tó
join to the eduction pipe of the steam engine. The turning plug of the cock
M has one passage diametrically across it, which, when that plug is in the
position shown in the Figure, forms an open communication L, L', between
the interior C of the covering box S and the said eduction pipe, which in
case of a condensing steam engine will be an open communication to the
condenser, so as to cause the space within the covering box S to be exhausted
of steam; or, in case of a non-condensing steam engine, the said open passage
L, L, will be nearly the same as a communication with the open air, so as
to prevent the space C, within the covering. box S,. from retaining steam

page_text: which is much stronger than the atmospheric pressure. R is a cross
passage leading from the cock M to the open air, in such manner that
any emission of steam from the end of R shall be visible. When the turning
plug of the cock M is turned, so as to .connect the passage L with the
cross passage R, then it will shew. (by an emission of steam at R) the
quantity of steam which may happen to leak around the circumference of
the piston F, and its packing, by which it fits into the cylinder H, H,.or to
leak between the flange a, a, b, b of the cylinder H, H, and the fitting
thereof against the plate D, D; for all the steam which so leaks through, and
thereby gains admission from the steam box A into the interior C of the
covering box S,' will pass therefrom through the passage L and cock M,
and make its escape at R into the open air, and the quantity which escapes
there will shew the amount of leakage; which, if the. fittings are all in
good order, should be an almost imperceptible quantity. But in case the
fittings are become so leaky that a considerable quantity of steam escapes
at R, so as to be a sensible loss to the steam engine, then that loss may
be prevented by turning the plug of the cock M so that it will stop the
passage R, and retain the steam in the covering box S from escaping, and at
the same time the cock M may (by means of two of the passages through
its turning plug) open a communication between the passage. L and another
passage, which leads from the cock M to the interior of the steam box A, so
that steam can pass freely therefrom, through 7, M, and L, into the interior C
of the covering box S, in which case the piston F will have no operation for
relieving the excess of pressure on the slide valve B, but that valve will act as
if the improvement were not applied to it. Note, the.cock M performs.the
same office, as already explained in reference to Figures 1 and 2, Sheet I., to
to be performed by a small opening (which may have a cock to close it) lead-
ing out of the covering box. S into the open air, or by a pipe (which may
have a stopcock), and which pipe extends from the interior of the.covering
box S to join to the eduction pipe of the engine. When those.cocks are both
shut, the loss of steam by. any leakage that may take place from defective
fittings will be stopped (in the same manner as would be done by the cock M.),
but there will be no operation of the improvement for relieving the slide
valve from excess of pressure. And note, the mode already described of making
a direct communication by holes drilled through the connecting piece E,
between the interior C of the covering box S. and the.eduction pipe or passage
K, cannot be used along with stopcocks, such as M, Figure 2, Sheet II., or the
two cocks above described. For the same purpose of preventing waste of leakage
steam, a hole may be drilled through the whole length of the connecting piece

page_text: E, Figures 1 and 2, Sheet II.; but in that case the cock M cannot
be used.
Figure 3; Sheet II., is a longitudinal section, and Figure 4: a transverse
section, of another variety of the slide valve constructed according to this part
of the improvements.. The slide valve B and the piston F, and their connect-
ing piece E, are the same as already described, and so is the cylinder H, H,
except as to its position, which is wholly within the steam box A, A; and that
end of the cylinder.H, H, on which are the flanges a, a, b, b, is furthest from
the slide valve B, and those flanges apply to, and slide against, the inner
surface of the plate D, D, which is the cover or top of the steam box A, A.;
hence, there is no such covering box as S, S, already described; but the -space
within the cylinder H, between the piston F and the plate D, D, corresponds
to the space within the said covering box, and the said space may-communicate
with the open air by a hole N, Figure 3, through the plate D, which hole may
have a cock for stopping it, and there may be a pipe with a stopcock in it
leading from another such hole as N, through the plate D, to join to the educ-
tion pipe of the steam engine; or otherwise, instead of such a cock and pipe
with a stopcock, there may be a perforation through the length of the con-
necting piece E, for. keeping an open communication from the said space
between the piston Fand the plate D to the eduction pipe or passage K.
The valve rod Iis flattened within the steam box A, A, with a hole through
the flattened part to admit the connecting piece E to pass through, and the
slide valve B, and the piston F, and its cylinder H, H, all partake of the sliding
motion that is communicated by the rod I to the said connecting piece E.
The rod I is shewn to be continued at 1, Figure 3, and the prolonged part 12
passes through another stuffing. box at the opposite end of the steam box A, A.
And note, such prolongation of the valve rod through double stuffing boxes is in
common:use in some steam engines; and the rod I, in Figure 1, Sheet I., might
be prolonged to pass through another stuffing box at the opposite end m of the
steam box A, if such double stuffing boxes are preferred. In Figures 3 and
4, Sheet II, flat blade.springs of steel are shewn at d, d, for ensuring that the
flange a, a, b, b, of the cylinder II, H, shall always be kept in close contact
with the flat surface of the plate D, D; the two ends of each of the blade
springs d, d, are lodged against the open-end of the cylinder H, H, at c, c, in
the same manner as the springs already explained in reference to Figure 1;
Sheet II. (but not represented in that Figure), but the middle parts of the
lengths of the springs d,d, Figures 3 and 4, Sheet II., bear against the
flattened part of the rod I; or they might bear against a suitable shoulder.or
prominence formed for that purpose on the connecting piece E, in which latter

page_text: case the re-acting force exerted at the middle parts of the lengths of the
springs d, d, would tend to press the slide valve B into contact with the
flat surface x, x, at the same time that the force exerted at the several ends
of the same springs d, d, tends, as already explained, to press the flange
a, a, b, b, of the cylinder H into close contact with the flat surface of the
plate D, D.
Figure 12, Sheet III., is a longitudinal section, and Figure 13 a
transverse section, of a slide valve constructed according to this part of the
improvements, and differing but slightly from that already described in
reference to Figures 3 and 4, Sheet II., the difference being that in Figures
12 and 13 the cylinder H, H, has a closed end b, a, p, b, a, in place of a
mere internal flange, or, in other words, that internal flange is continued in an
entire surface p over the end of the cylinder H, H, forming a closed end
b, a, p, b, a, thereto; but there is a prominent border margin a, b, a, b, all around
the outer surface of that closed end, which margin a, b, a, b, applies to and
slides against the flat surface of the plate D, in precisely the same manner
as the flange a, b, a, b, in the former Figures, because the additional part p,
which forms the closed end to the cylinder H, H, does not actually touch the
surface of D, and one or more holes must be drilled througs the end
carry away any steam which may leak through the contact between D and
a, b, a, b. Flat blade springs of steel d, d, are applied, in the manner already
explained in reference to Figures 3 and 4, to ensure close contact of a, b, a, b,
with D, and the connecting piece E is perforated for permitting the escape of
steam. The action of all the parts of Figures 12 and 13 is precisely the same
in every respect as already described in reference to Figures 3 and 4,
Sheet II. But there is another difference of construction in Figures 12
and 13, videlicit, that the plate D, D, is not (as in the former cases) the
flat top of the steam box A, A, but is a separate flat plate of metal D, D,.
which is fixed within the steam box A, A, by means of brackets Y, Y,
firmly fastened to the upright sides m of that box, and the plate D, D, is
fastened to the brackets Y, Y, by screws, the position of the plate D, D,
being such that the surface of D, D, will be exactly parallel to the flat sur-
face x, x.
Figure 10, Sheet III., is a longitudinal section, and Figure 11 a transverse
section, of another variety of the slide valve constructed according to this part
'of the improvements. The slide valve B and piston F, with their connecting
picce E, are all the same as already described; and the cylinder H, H, has a.
closed end D, which is continued in the form of two long bars h, h, which
extend along each side of the cylinder H, H, in the directions of tangents to its

page_text: exterior circumference; and each of the said, bars h, h, applies upon two
bearing rollers X, X, which are mounted on fixed centre pins fastened to the
sides.m, m, withinside of the steam box A. In this manner the cylinder H, H,
is sustained on four bearing rollers, such as X, X, so as to be capable of
moving freely thereon, in order that the cylinder H, H, with the piston F
within it, may accompany the slide valve B in its sliding motion. A small
passage is drilled through all the length of the connecting piece E, for con-
veying away into the eduction passage K any steam that may be in the space
between the piston F and the closed end D of the cylinder H, H, or that
may get into that space by leaking around the piston F; and the pressure
of steam within the steam box A, A, at the same time that it acts with a
tendency to force the slide valve B towards the surface x, x, also presses
against the piston F in a contrary direction, so as to counterbalance or
counteract a great portion of the said tendency, in the same manner as already
explained respecting the action of the piston F, in the preceding Figures.
The re-action for all the counterbalancing or counteracting force which is thus
exerted by the piston must be borne by the bars h, h, resting on the rollers X, X.
And note, instead of those rollers two straight edges may be formed at the
sides m, m, of the steam box A, A, to project out from those sides.suitably
for forming lodgments for the bars h, h, to slide upon when the cylinder H, H;
accompanies the slide valve B in its sliding motion as aforesaid. The valve
rod I is the same as last described, with two stuffing boxes and a flattened
part, through a hole in which the connecting piece E passes; and the open end
of the cylinder H, H, has two projecting pieces c, c, which enter into other
holes in the flattened part of the rod I, so as to communicate to the
cylinder H, H, the same sliding motion that is communicated to the piston F
and to the slide valve B by the action of the rod I on the connecting piece E;
springs are not required in this arrangement. And note, in any of the Figures
1, 2, 3, 4, 10, 11, 12, 13, Sheets II. and III., the packing around the circum-
ference of the piston F, whereby it fits tight into the interior of the cylinder H, H,
may be any suitable kind of packing such as is in use: for steam pistons, either
packing of hemp or cotton compressed, or else expanding metallic packing, in
case of slide valves for steam engines; or, in case of slide valves for engines
for water, air, or gas, or liquid, or fluid, packing of leather or cloth may be
used in like manner as is done in pumps.
Figure 7, Sheet II., is a' section of a substitute for the piston F. and
cylinder: H, H, in the improvement herein-before described in reference to
Figures 1 and 2, Sheet II. .In Figure 7, 6, H, n, n, H, b, is a section of the
cylinder that is to be substituted for the cylinder H, H, Figure I., Sheet II.,

page_text: the external flange b, b,. Figure 7, applying to and fitting against the flat
surface of the plate D, D, Figure 1, in the same manner as the external flange
of the cylinder H; H,. represented in that Figure. In Figure 7, F is the
piston, and E the connecting piece to the slide valve, and G the nut for
fastening the piston F.to the connecting piece E. The piston F, Figure 7,
is not fitted into the interior of the cylinder H, H, but the piston F has a
prominent border rim f,f, which fits over the outside of the cylinder at n, n,
in the manner of the lid of a circular snuff box, but leaves the piston F capable
of moving in respect to the cylinder H, H, as much as is requisite; and, in
order to prevent leakage of steam between the fitting (at f, n, f, n). of the
piston with the cylinder, a thin flexible band P, P, of any suitable substance,
such as india rubber or india rubber cloth, is applied within the interior
circumference of the part n, n, of the cylinder H, and also, within the interior
circumference of a hollow e, e, of corresponding size within the piston F, so as
to form a sort of lining to the said interior, which lining P, P, overlaps the
crevice between the part n, n, of the cylinder and the part e, e, of the
piston F, in the manner shewn in the Figure. The said flexible band P, P, is
held in place within the interior of the cylinder H, H, by an interior hoop of
metal p, p. And note, in case of water or other liquid, or air, or gas, being
used in the engine to which such valve is applied, the said flexible band P, P,
may.be of leather or cloth saturated with grease, or otherwise suitably prepared,
as is usually done for pumps. The cylinder and piston, Figure 7, being
substituted for the cylinder and piston in Figures 1 and 2, Sheet II., the action
thereof will be in every respect the same as already described in reference to
those Figures, suitable springs being applied (in the manner already explained)
to ensure that the flange b, b, of the cylinder H, H, shall always keep in close
contact with the flat plate D, D, Figures 1 and 2.
In Sheet III., Figure 15 is a section of a cylinder and piston somewhat
similar to Figure 7, but suitably modified to serve as a substitute for the
cylinder H, H; and piston F, in Figures 3 and 4, Sheet II., and in Figures
10 and 11, Sheet III., and more particularly in Figures 12 and 13, Sheet
III., and Figure 14, Sheet III., is a longitudinal section, like Figure
12 in every respect except as to the substitution of the cylinder H, H,
and piston F, Figure. 15, in place of the cylinder and piston shewn in
Figures 12 and 13, wherefore both Figures 15 and 14 may be consulted
for the description now about to be given. The cylinder H, H, Figure
15, is made with a closed end b, a, p, a, b, as already explained in refer-
ence to Figures 12 and 13; but the piston F, F, Figures 14 and 15, is
ormed with a deep cylindrical groove to receive the open end of the

page_text: cylinder H, H, and stuffing of hemp, cotton, or other suitable elastic sub-
stance is applied at the bottom of that groove, to make a tight fitting, and
prevent the passage of steam between the cylinder H, H, and the piston F;
and several small holes x, x, Figure 15, are drilled through the bottom of the
said deep groove, so as to admit steam to act behind the packing in.that groove,
in order to press the packing towards the end of the cylinder. H, H, which
end enters the same groove as already stated. E is the connecting piece, and G
the nut for uniting the piston F. to the slide valve: B; and d, d, are the steel
blade-springs for causing the closed end of the cylinder H, H, to keep in
close contact with the plate D, D... In Figure 15, a, a, shews. the prominent
margin at the closed end of the cylinder H, H, which margin is to apply to
and slide against the plate D, D, as appears in Figure.14, the part P of the
said closed end of the cylinder not being in actual contact with D, but holes
are drilled through that part p, as already explained in reference to Figures
12 and 13 in Sheet I.
Figure 3 is à longitudinal section, and Figure 4 a transverse section,
of a different kind of slide valve, which is made in form of a hollow box
B, B, and the steam is introduced into the hollow thereof by means of
a cylindrical steam pipe A, A, passing through a stuffing box Z, to permit
of the requisite sliding motion of the .slide valve .B, B, the interior hollow
of which is by that means kept always fully supplied with steam from
the boiler; and the slidé valve B, B,. has two openings, r and s, out of it;
at that side of it which applies to and fits. against the flat surface. x, x;
in which surface are the two usual. apértures t and w of the side pipes or
passages T and W, which communicate..with the two ends of the steam
cylinder of the steam engine. The requisite sliding motion is communicated
to the slide valve B, B, by means of a prolongation I of the steam pipe A;
that prolongation (which serves for a valve rod) being a solid rod, of the same
size as the outside of the steam pipe A, and passing through another stuffing
box to the outside, so that motion can be there given to the outer end of I
for producing the requisite sliding motion of the slide. valve B, B, within its
steam valve-casing n, D, D, n.. The space around: I and A, between the two
stuffing boxes Z and z, serves the purpose of a steam box L, into which steam
from the boiler is continually supplied through the steam pipe M, and the
steam so supplied surrounds the end of the steam pipe A, at the part thereof
where the solid prolongation I commences, and the steam is freely admitted
into the hollow of the steam pipe A, through several oblong openings a, a,
which are cut out in the circumference of the pipe A, at the part thereof
which is exposed between the two stuffing.boxes Z and . The sliding motion

page_text: so given to the slide valve B, B, will cause one or other of the openings r or
s of the slide valve B, B, to come into open communication with one or other
of the apertures t or w, so as to admit steam from the interior hollow of the
valve B, B, either through 'r, 't, and T, to go into one end of the steam cylin-
der when the slide,valve B, B, is. slided in the direction towards T, or else
through s, w, and W to go into the opposite end of the steam cylinder when.
the slide valve B, B, is slided in the.contrary.direction towards W; and when-
ever the slide valve B, B, is so slided.in: either direction, one or other of the
extreme ends of the slide. valve. B, B, will uncover and open one or other of
the apertures tor.w, so as to permit the. 'escape of waste steam from the
opposite end of, the steam cylinder to that end thereof into which steam is at
the same time admitted through one or other of the openings r 'or s, as afore-
said. The waste steam which so escapes enters into the slide valve casing
n, D, D, n, and passes away therefrom through the eduction pipe K, which
proceeds from that steam valve-casing, and the interior C.thereof is not kept
filled with steam coming from the boiler, as is the case in: all the other
Figures herein-before described, but, on, the contrary, in the present.case
(Figures 3 and 4, Sheet I.) the steam, coming from the boiler enters into the
interior hollow, of the slide: valve B, B, and the interior, of the slide valve
casing n, D, D, n, wherein the, slide valve: B is enclosed, always communicates
openly, with the eduction pipe K, so that in the case of a non-condensing, high-
pressure steam engine the interior C of, the slide valve casing.cannot remain
filled with steam of much greater strength than the atmospheric pressure to
surround: the slide. valve B, B;. or, in case., of a condensing engine, the space
within the interior, C. of the slide valve casing, n, D, D; n, will always be in
communication (through the eduction pipe: K) with the condenser, so as
to be kept exhausted of steam. The pressure. of the steam; from the boiler,
within the interior hollow of the slide valve B, B, will have no other influence
upon the contact of the slide valve, B, B, with the flat surface x, x, against
which it slides, except inasmuch as that, the openings r and s are parts of the
slide valve B, B, which do not receive, the pressure of the steam within the
hollow, of the slide! valve B, B, but which pressure all other parts of the
interior of the boundaries of that hollow, do receive, and, in consequence, there
would be some tendency to remove the slide valve B, B, away from its contact
with the flat surface x, x; but in order to overbalance and prevent such ten-
dency from being operative on the slide valve B, B, a small circular piston F
is applied opposite to each of the openings r and s, those pistons being fitted
into two short. cylinders H, H, which are formed of the same piece of metal
with the slide valve B, B, and the flat surfaces of the two pistons F, F, bear
1.1
open c

page_text: against the inside flat surface of the cover D, D, of the slide valve casing, and
the said pistons F, F (which, accompanying the sliding motion of the slide
valve B, B), slide against the said flat surface. Those surfaces, therefore,
receive the force of pressure which the steam within the hollow of the slide
5 valve B, B, exerts against the pistons F, F, and consequently there is so much
less force operative in the direction which would tend to remove the slide
valve away from the flat surface x, x. The area of each piston F, F, should
be at least equal to and will be be better to be greater than the area of that
opening ror s, to which each piston is opposite. The end of the hollow steam
pipe A, which passes through the stuffing box Z, receives steam from the space
within the steam box L, through the oblong openings a, a. That steam box
L is situated at the end of the steam valve-casing n, D, D, n, and is kept
separated therefrom by the stuffing box Z. The prolongation I of the steam
pipe A passes through the outer stuffing box z to the outside, and that prolon-
gation being the same size as the steam pipe A, the pressure of the steam
within the steam box L will have no action to move the steam pipe A or the
prolongation I thereof endways through their respective stuffing boxes.
Z and z.
Figure 16, Sheet III., is a longitudinal section, and Figure 17 a transverse
section, of a slide valve very similar to that last described, and operating
in the same manner. The slide valve B, B, is hollow, but the cylindrical
steam pipe A, A, (instead of being part of the slide valve itself, and con
sequently moveable endways therewith) is a fixed pipe, which passes through
all the length of the hollow slide valve B, B, with a stuffing box Z, Z, at each
end of the slide valve B, B, fitting closely to the outside of the fixed pipe A, A,
to prevent escape of steam when the slide valve B, B, is moved with its proper
sliding motion along the fixed pipe A, A. The steam pipe A, A, is fastened
into the two ends u, u, of the slide valve casing n, D, D, n, and is supplied with.
steam from the boiler introduced by a steam pipe, such as A', at one end (or at
both ends) of the steam pipe A, A, and that steam passes out through one or
more openings at a, in the steam pipe A, A, near to the middle part of its
length, within the hollow of the slide valve B, B, so as to keep that hollow
always supplied with steam from the boiler. The requisite sliding motion is
communicated to the slide valve B, B, by means of two valve rods I and II, which
are both connected to one end of the slide valve B, B, and they, pass through
two stuffing boxes in the same end n of the slide valve casing, one of those
valve rods being at each side of the steam pipe A, in order to act more equably
on the slide valve B, B, but the outer ends of the two rods I and L are con-
nected together by a short cross head, which is jointed to one rod X, to which
B

page_text: the requisite endway motion is given, in order to be transmitted by the two
rods I and II, to the slide valve B, B, within the slide valve casing. The
openings and s in the slide valve B, B, and their action in sliding over the
apertures t and w of the side pipes or passages Tand W, is the same as already
And so is the action of
described in reference to Figures 3 and 4, Sheet I.
the piston H, Figures 16 and 17, Sheet III., except that there is only one
such piston instead of two, as in Figure 3, Sheet I., the area of that one piston
in Figures 16 and 17 being as large or larger than the area of the two
apertures t and w together. Also the piston H, shewn in Figures 16 and 17
(instead of being a circular piston) is represented to be of a rectangular form,
and instead of fitting into a cylinder it has a prominent border, adapted to
enter into a deep groove of a corresponding size and shape, formed in the
metal of the slide valve A, A, around an opening G through that metal, see
Figures 18 and 19, which are detached sections of the said piston H on a
larger scale, and at the bottom of the said deep groove a stuffing of hemp,
cotton, or other suitable elastic substance is applied to make a tight fitting with
the prominent border of the piston H, which border enters into the said deep
groove, and small holes x are drilled through into the bottom of the said groove
to admit steam behind the said stuffing, all which (except as to the rectangular
form of the piston) is the same as already fully explained in reference to
Figure 15, and therefore need not be repeated. The outer side of the piston
H, which applies to and slides against the inside of the flat cover D, D, of the
slide valve case, is only a border margin around the piston H, as is shewn in
Figures 16, 17, 18, and 19, and the middle part of the piston H does not
actually touch the inside of the flat cover D, D; also a hole is drilled through
the said middle part, which does not touch, in order to admit steam into the
space which is thus left between that middle part and the flat cover D, D. And
note, respecting the outer sides of the two pistons F, F, Figures 3 and 4,
Sheet I., instead of being mere flat surfaces (as herein-before mentioned) at
those sides of the said pistons which apply to and bear against the inside flat
surface of the cover D, D, those sides of the said pistons may be made as above
stated, and as represented in Figures 18 and 19, with only border margins
around their circumferences to apply to and bear against the said flat surface
of the cover D, D, without actually touching at the middle parts of the
pistons within those margins. And note, in Figures 16 and 17 the steam
pipe A, A, and its stuffing boxes Z, Z, are drawn too small in diameter, but
should be the same size as the steam pipe A, A, in Figures 3 and 4, Sheet I.
Note, in all the several Figures 1 and 2, Sheet I., and Figures 1 and 2,
Sheet II., and Figures 3 and 4, Sheet II., and Figures 12 and 13, Sheet III.,

page_text: and F Tures 10 and 11, Sheet III., and Figures 14 and 15, Sheet III., the
slide ive is left at liberty to separate from its contact with the surface against
which it slides, in case of water getting into the cylinder of the steam engine,
as already fully explained in reference to Figures 1 and 2, Sheet I. But in
Figures 3 and 4, Sheet I., and Figures 16, 17, 18 and 19, Sheet. III., the
slide valve must be always retained (by suitable guiding fillets) in close con-
tact with the surface against which it slides, because the stuffing boxes of the
cylindrical steam pipe by which steam is introduced into the hollow within the
slide valve, will not allow of the said valve being left at liberty. And note, in
order that the contact of the slide valve B, B, with the flat surface x, x,
Figure 16, against which it is to slide, may be always allowed. to take place,
although the fitting surfaces will wear slowly. away by long use, the cylindrical
steam pipe A, A, is screwed to one of the ends n of the slide valve casing
with a large flat flange near to A¹, and the holes through that flange for the
screws being slotted, when required, will permit the pipe A to be re-fixed as
much nearer to the flat surface x, x, as may be required to make up for
wearing away of the surfaces. Also in Figure 3, Sheet I., the hollow steam
pipe A may be screwed to the end of the slide valve B, B, by a large flange
with slotted holes for the screws, so as to permit of the pipe A, A, being re-
fixed to the end of the slide valve B, B, as much nearer to that surface thereof
which fits against the surface x, x, as the wearing away of the fitting surfaces
may require. Or otherwise, in case of the steam pipe A, A, (and its pro-
longation I) being made in the same piece of metal with the slide valve B, B,
as is represented in Figure 3, Sheet I., then those parts of the stuffing
boxes Z, and z, which retain the packing endways in those boxe and which parts
are called the bushes and the glands of the stuffing boxes, may be made with
their central holes (which are truly fitted to the steam pipe A and the rod I)
somewhat excentric to their outsides, which are fitted to go into the stuffing
boxes, so that the said bushes and glands, which are rings and tubes, although
truly circular both outside and inside, will nevertheless have a thick side and
a thin side, and therefore by turning the bushes and the glands in their places
in the stuffing boxes, at times when the packing is renewed, the said central
holes of the bushes and glands through which the steam pipe A, A, and rod I
are to pass, can be set as much nearer to the surface x, x, as the wearing
away of the fitting surfaces may require.
Figure 5, Sheet II., is a vertical section, and Figure 6 a plan, of a regulating
slide valve, which is used as a regulator in locomotive steam engines, for regu-
lating the quantity of steam that is to be permitted to pass out of the boiler M
into the steam pipe A, A, on its way to the engines. The pressure of the

page_text: steam against such a valve B presses it with such forcible contact to the fixed
surface x, x, against which the valve B slides as to cause great friction, and
consequently much force is required for moving the regulating slide valve.
Figures 5 and 6 shew how a piston F is to be fastened by means of connecting
pieces E, E, and nut G to the regulating slide valve B, B, in order that the
pressure of the steam against the piston F may act in a contrary direction to
the pressure of the steam against the regulating slide valve B, so as by counter-
acting the greater part of the latter pressure to diminish the friction, and render
the valve B capable of being easily slided against its fixed flat surfaces x, x. The
piston F (which is represented in section) is fitted into a cylinder H, H,
with metallic or other packing, so that the steam cannot pass between the
piston F and the cylinder H, H, and one end of the cylinder H, H, has
an external and internal flange b, b, a, a, the surface of which flange
applies in close contact with the flat surface of a fixed plate D, which
is firmly fixed by a suitable bracket n and stays m, m, to the piece
of metal on which the surface x, x, is formed, and which may be the
same piece with the mouth or entrance into the steam pipe A, A, the
surface of D being exactly parallel to the surface x, x, and the flange a, a,
b, b, of the cylinder H, H, slides against the surface of D, whenever the regu-
lating slide valve B, B, slides against the surface x, x. I is the valve rod, by
means of which the regulating slide valve B, B, is slided in the usual manner
of such valves in locomotive engines. Any steam which may gain admittance
by leakage into the space between the piston F and the fixed plate D is
allowed to escape from that space through the small pipe o, o, Figure 5, into
the open air at the outside of the boiler M, through a stopcock on the end of
that pipe, which, when open, will shew how much steam is leaking between
the piston F and its fitting into the cylinder H, or between the flange a, a, b, b,
of the cylinder H, H, and its fitting against the fixed plate D, which leakage
ought to be almost insensible if the fittings are in good condition; but if those
fittings get out of order, and the leakage becomes considerable, then it may be
stopped by closing the said cock, although in such case the piston F will cease
to operate for counteracting the pressure of the steam against the regulating slide
valve B. Note, the construction and action of the piston F, and its cylinder
H, H, is the same as already explained in reference to Figures 3 and 4, Sheet II.,
and flat blade springs of steel such as those described must be applied in Figures
5 and 6, Sheet II., (although not there represented), for ensuring the contact
of the flange a, a, b, b, of the cylinder H, H, with the flat surface of the plate D.
Figure 8, Sheet II., is a horizontal section of a safety valve for steam
and other engines, for permitting the escape of superfluous steam, air, gas,

page_text: water, or liquid, or fluid from the boiler or other place of confinement,
whenever the pressure becomes greater than it is intended to be; such
safety valve, if of small size, will not open sufficient passage for the prompt
discharge of superfluous steam, and safety valves of a large size require to be
loaded with very heavy weights, or great force of springs, or with levers for
multiplying the effect of that weight or force. In Figure 8 it is shewn how a
piston F, fitted into a cylinder H, H, can be applied to the horizontal spindle
E of a safety valve D, of large size, so as that the pressure of the steam against
that piston F shall counteract a part of the pressure which the steam is at the
same time exerting against the safety valve D, with a tendency to open the
same; but the tendency of the pressure against the piston F being to close
the safety valve D, that valve only requires a small weight, or force of spring
(or a small multiplication of the effect of such weight or force by leverage), in
order to keep the safety valve D closed. B, B, is a hollow box, into which
steam from the boiler ascends by the passage denoted by the circle R. The
box B, B, has a circular aperture at one end, and to the flat border around that
aperture.the valve D is fitted externally (or it might be a conical fitting); and
there is another circular aperture of smaller size at the other end of the box
B, B, and to the flat border around that smaller aperture, the cylinder H
is applied internally, the end of the cylinder H, H, having a flange b, b,
which fits with close contact against that border, but is not fastened thereto,
and flat blade springs d, d, are applied with their ends against the other end of
the cylinder H, H, so as to ensure such contact, the middle parts of the lengths
of those springs d, d, bearing against a fixed bar which extends across the
interior of the box B, B, but is not represented. The construction of the piston
F and its cylinder H, H, and the said flat blade springs d, d, is so nearly the
same as already explained in reference to Figures 1 and 2, Sheet II., that it
is unnecessary to enter into a more detailed description. The horizontal
spindle E of the valve D is also the rod of the piston F (for both the valve
D and the piston F are firmly fastened on that horizontal spindle E), and the
spindle E is retained in suitable guides J, J, at each end of it; and to the
extremity of that end on which the valve D is fixed (where that extremity
protudes out beyond the guide J) the force of a suitable weight or spring is
applied by means of an elbow lever for keeping the safety valve D closed.
Such an elbow lever is shewn in Figure 9, which is next to be described, and
which Figure serves to explain how the box B, B, Figure 8, is like a head at
the top of an upright neck R, which ascends from the top M of the boiler,
being fastened to that top by a flange. And note, a piston such as F on the
spindle of a valve such as D is a well-known arrangement, and commonly.

page_text: used for the eduction valves of large condensing steam engines, for counter-
balancing part of the pressure on such valves, but such piston has not been
used for safety valves, and this part of the improvements is confined to safety
valves exclusively.
Figure 9, Sheet II., is a vertical section of another safety valve, which
is very similar in construction to Figure 8, already described, except that
in Figure 9 (in place of a piston fitted into a cylinder). a smaller internal
safety valve D' is fastened on the same horizontal spindle E, as the principal
or large safety valve D. The said smaller internal safety valve D¹ fits
internally to the flat border around the small aperture already described
at one end of the box B, B, at the same time that (and in like manner as) the
larger safety valve D fits externally to the flat border around the larger aper-
ture at the other end of the box B, B, but both valves may have conical fittings
if preferred. The same pressure of steam which tends (in the usual manner
of safety valves) to open the larger external safety valve D also tends (but
with less force) to close the smaller internal safety valve D¹, so that a great
part of the force exerted for opening the valve D is counteracted, and only a
small force is required to be exerted by the elbow lever L, in order to keep
both valves closed; but whenever the pressure is sufficient to overcome the
force so exerted by the lever L, and open the larger external safety valve D,
the smaller internal safety valve D' will also be opened at the same time, so
The elbow lever
as to afford a double passage for the escape of the steam.
L is moveable about a fixed centre pin 9, which is supported in a small bracket
projecting out from one end of the box B, B. The lower end of the vertical
arm of the lever L bears against the protruding extremity of the horizontal
spindle E, beyond the guide J, for that extremity, and the long horizontal arm
of the lever L, has a small weight p applied upon it in the usual manner of
a steelyard lever for safety valves, but with a much smaller weight than usual.
Or, instead of the weight p, a spring may be applied in the well-known manner
of the safety valves for locomotive engines. And note, the large valve D and
smaller valve D¹ on the same spindle E is an arrangement which is well known
and commonly used for steam valves in some steam engine, and are called
double-beat valves, but no double-beat valves have been hitherto used for safety
valves, and this part of the improvements is confined to safety valves ex-
clusively, being the application of double-beat valves for safety valves; and
the foregoing description and Figure 9 is by way of example of the mode of
applying one (which is the simplest) kind of double-beat valves; but there are
other well-known constructions of double-beat valves which may be substituted
for the simple kind of double-beat valves shewn in Figure 9, Sheet II.

page_text: It is not necessary to give any further explanation (than is above given) for
the mode of applying such other kinds of double-beat valves so that they
may perform in the same manner as aforesaid.
Having now described the said improvements, I, the said Edmund Wheeler,
do hereby declare that the new Invention, whereof the exclusive use is granted
to me by the Letters Patent herein-before recited, consists in the following
particulars, viz:
Firstly, the improvement herein-before described in reference to Figures 1
and 2, Sheet I., of the Drawings hereunto annexed, of affixing an additional
flat sliding plate to the sliding valve, the plane of such plate being exactly
parallel to the flat fitting surface of the slide valve, but at some distance from
that surface, and the border margin of the said additional plate applying with
close contact against a fixed plate, which is exactly parallel to the fixed flat
surface against which the side valve applies and slides, in order that the
steam which tends to press the slide valve forcibly towards the said fixed flat
surface (in the usual manner of such slide valves) may, by virtue of the im-
provement, also press at the same time in a contrary direction against the
said additional sliding plate of the slide valve, so as by counteraction to relieve
the slide valve from all excess of pressure against the said fixed flat surface
beyond what is desirable for retaining the slide valve in close contact with that
surface; the slide valve, with this improvement applied to it, being neverthe-
less left at liberty (in the usual manner of such sliding valves) to separate
from its said contact with the said surface in case of water getting into the
cylinder of the steam engine; the said improvement being applicable to all
kinds of steam engines in which slide valves are used, and most particularly
applicable to locomotive steam engines, and being also applicable to other
engines in which slide valves are or may be used.
Secondly, in the improvement herein-before described in reference to
Figures 1, 2, and 7, Sheet II., with all the variations in the construction of
the same improvement as herein-before described, in reference to Figures 3
and 4, Sheet II., and Figures 12 and 13, Sheet III., and Figures 10 and 11,
Sheet III., and Figures 14 and 15, Sheet III.; this part of the improvements
consisting in affixing a circular or other shaped piston to the sliding valve,
that piston being suitably adapted to a cylinder (or other shaped prismatic
container for such piston) in order that the steam which tends to press the
slide valve towards the fixed flat surface against which it slides may also at the
same time press in a contrary direction against the said piston, so as (by coun-
teraction) to relieve the slide valve from excess of pressure against the said. fixed
flat surface; the said cylinder (or other shaped prismatic container), into

page_text: which the said piston is so fitted, partaking, in all cases, of the sliding motion
of the slide valve; and the slide valve being left at liberty (in the usual manner
of such slide valves) to separate from its contact with the flat surface against
which it slides, in case of water getting into the cylinder of the engine.
Thirdly, in the improvement herein-before described in reference to
Figures 3 and 4, Sheet I., and with a variation in the construction of the
same improvement as herein-before described in reference to Figures 16, 17,
18, and 19, Sheet III.; this part of the improvements consisting in intro-
ducing the steam from the boiler into the interior hollow of the slide valve by
means of a cylindrical steam pipe fitted into stuffing boxes, so as to permit of
the sliding motion of the slide valve without interfering with the supply of
steam to the said interior hollow of the slide valve; also in applying pistons (or
a piston) to the said hollow slide valve, for counterbalancing the effect of the
pressure of the steam therein.
Fourthly, in the improvement herein-before described in reference to
Figures 5 and 6, Sheet II., of affixing a circular (or other shaped) piston to
the regulating slide valve, which is commonly used as a regulator of the quan-
tity of steam that is to be permitted to pass from the boiler into the steam
pipe in its way to the engine. The said piston being fitted into a cylinder (or
other shaped prismatic container), which, as well as the piston, partakes of
the sliding motion of the regulating slide valve, and the pressure of the
steam against the piston, relieving the regulating slide valve from being too
forcibly pressed by the steam towards the surface against which the said valve
slides.
Fifthly, the improvement herein-described, in reference to Figures 8 and 9,
Sheet II., either of applying a circular (or other shaped) piston fitting into
a cylinder (or other shaped prismatic container) to the spindle of a safety
valve for steam or other engines, as in Figure 8, in such manner that the
pressure of the steam against such piston may counteract a great part of the
pressure wherewith the same steam tends (in the usual manner) to force open
the safety valve in order that a large safety valve may be used, with only a
small weight (or force of spring) for loading such valve; or else, instead of
such piston applying another smaller valve to the spindle of a safety valve, as
in Figure 9, so that the pressure of the steam, which tends (as usual) to open
the ordinary valve, may at the same time tend to close the other smaller valve
on the same spindle, and thereby the latter tendency will counteract a great
part of the former tendency, so that a small weight (or force of spring) will
suffice for loading such double safety valve, and when the same is opened both
the valves will give passage for the escape of the steam in the manner of what