IMPROVEMENTS IN STEAM ENGINES
Year: 1856

page_text: LETTERS PATENT to Thomas Charlton, of Brentwood, in the County of
Essex, Engineer, and William Turnbull, of Rotherhithe, in the County
of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES."
Scaled the 14th November 1856, and dated the 26th May 1856.
PROVISIONAL SPECIFICATION left by the said Thomas Charlton and
William Turnbull at the Office of the Commissioners of Patents, with
their Petition, on the 26th May 1856.
We, THOMAS CHARLTON, of Brentwood, in the County of Essex, Engineer,
and WILLIAM TURNBULL, of Rotherhithe, in the County of Surrey, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN STEAM
ENGINES, to be as follows:-
This Invention consists in the mode and arrangement of making and
working the valves of steam engines, so that the pressure of the steam on the
valves is obviated, the steam carried to the greatest limit of expansion, and
conveyed to within a short distance of the termination of the stroke. Free
exit for the exhaust steam to the atmosphere or condenser is secured by
allowing suitable lap on the steam valve. The steam valve has two internal
passages at the end and two small passages on the side passing through the
face, and communicating with a small steam pipe attached to the main steam
pipe; the expansion valve works in the back of the steam valve, and has two
end passages communicating with the ends of the steam valve, and one passage
on the back which communicates with the main steam pipe. The back of the.

page_text: steam chest cover, the end of which is enlarged to work on the back of the
expansion valve, is pressed on the same by an india-rubber packing or any
other suitable method; the exhaust steam passes off in the usual way through
the exhaust pipe to the atmosphere or condenser, but a portion of the same
passes into the steam chest on the outside of the valves for lubricating them.
Or, the exhaust steam may be conveyed into the chest without an exhaust
passage in the cylinder, and from thence to the condenser or atmosphere.
This method is equally applicable to the single valve by conveying the steam
from the boiler into the valve, and passing the exhaust into the chest and from
thence to the condenser or atmosphere. The mode of working the valves is
as follows: The steam valve is worked with the ordinary link motion, and
the expansion valve is worked from a pin fixed in the centre of the link,
whereby the proper movements are obtained, and are suitable for back or foro
gear, whereby reversing gear may be dispensed with. Or, the valves may be
constructed thus:-The steam pipe may be attached to the cylinder with two
ports passing through the cylinder face communicating with two passages on
the side of the steam valve communicating with two similar passages passing
through the face of the expansion valve, and passing into end passages, through
the end passages of the steam valve, and thus to the inside of the cylinder.
The valves are kept up to their faces by a spring from the steam chest door,
or by packing, set screw, or other suitable method. The exhaust steam may
pass into the chest and thence to the condenser or atmosphere, or it may pass
directly from the steam valve into an exhaust pipe in the usual way.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Charlton and William Turnbull in the Great Scal
Patent Office on the 26th November 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
CHARLTON, of Brentwood, in the County of Essex, Engineer, and WILLIAM
TURNBULL, of Rotherhithe, in the County of Surrey, Engiucer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Пer heirs and successors, give and grant unto us, the said
Thomas Charlton and William Turnbull, her special licence that we, the said
Thomas Charlton and William Turnbull, our executors, administrators, and
assigns, or such others as we, the said Thomas Charlton and William Turnbull,

page_text: our executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain, and Ireland, the Channel Islands, and
Isle of Man, an Invention for "IMPROVEMENTS IN STEAM ENGINES, upon the
condition (amongst others) that we, the said Thomas Charlton and William
Turnbull, or one of us, or our executors or administrators, by an instrument in
writing under our, or their, or one of our or their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office, within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that we, tho said Thomas Charlton and William
Turnbull, do hereby declare the nature of our said Invention, and in what.
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had to the
Drawings annexed, that is to say:-
Our Invention consists, first, in improvements in the construction, arrange-
ment, and mode of working the valves of steam engines.
Second, in connecting the steam valve or valves direct to the boiler or
boilers, by a yielding steam pipe or hollow piston.
And, third, in working the expansion valves in conjunction with the cylinder
valves of steam engines by two excentrics connected to one or more links.
The pressure of the steam on the valves is obviated, and the steam may be
carried to the greatest limit of expansion, and conveyed to within a short
distance of the termination of the stroke. Frec exit for the exhaust steam to
the atmosphere or condenser is secured by allowing suitable lap on the steam
valve. The exhaust steam passes off in the usual way through the exhaust
pipo to the atmosphere or condenser, but a portion of the same passes into the
steam chest on the outside of the valves for lubricating them; or the exhaust
steam may be conveyed into the chest without an exhaust passage in the
cylinder, and thence to the condenser or atmosphere. Steam from the boiler
may pass direct into a single valve, through the. back or side, or sides thereof,
the exhaust escaping into the steam chest, and thence to the condenser or
atmosphere.
The manner in which our Invention may be carried into effect is exemplified
in the annexed Drawings.
Figure 1 is a section of a steam engine to which parts of our improvements
are applied; Figure 2. a side view of the same. A is the cylinder: A' the

page_text: piston; A, the piston rod, which is jointed to the connecting rod A³, by a short
cross-head A, on which the sliding blocks A' are mounted, and which slide in
the guides A, to keep the piston rod and piston moving parallel. B is a
crank (on the shaft B'), to which the connecting rod A³ is attached; on the
shaft B', the excentrics B, 133 are fixed, which are embraced by tho excentric
straps B3, B, which are firmly secured to the excentric rods B, B', the ends
of which are forked and jointed to the double slotted link C by the pins C³, C³.
The excentrics are set on the crank-shaft B', to correspond to a backward or
orward motion of the engine. The link is suspended by a rod C³ jointed
to it at C' by a pin; the other end of the rod is jointed to a bracket C³, in a
similar manner. The bracket is permanently fixed to any suitable part of the
framing or foundation plate, or to any suitable part of the boiler or engine.
The rod C³, serves to keep the link in proper position, but at the same time it
is capable of vibrating while being acted on by the excentrics B2, B3, through
their straps and connecting rods B, B, B, B'. In the slot D, a block D' is
fitted; the sides of the link and block aro flush, or nearly so.
D² is a con-
necting rod with both ends forked (in the same plane), one end of which spans
the link C, and embraces the block D', and is jointed to it by a pin a, which is
passed through them. The other forked end of the rod D³ is jointed at D³, by
a pin to the valve spindle D', for the purpose of giving motion to the slide
valvo D, which has ports D, D (one in each end), which are formed right
through from front to back. These ports correspond with ports c, c, in the
cylinder face, the steam ways of which lead to their respective ends of the
cylinder. These ports are nearer to each other than those in the valve, to
allow space for the stroke. E is the expansion valve which is formed hollow,
and has two ports d, d, in its face to correspond exactly with the ports or
passages D, D, which pass through the steam passages D'; a space d' is
formed between the face of the expansion and steam valves, to allow the
exhaust steam to play freely between them, and to be in communication with
the exhaust steam chest E¹, E', which is a space surrounding the valves
completely, excepting at the parts where their faces touch. In the centre of
the back of the expansion valve E, an induction steam port e is formed;
this communicates with or rather branches off to the ports d in the face of
the valve.
Figure 3 is a back view or plan of this valve; and Figure 4, a longitudinal
section; e is the port in the back, and d, d, the ports in the face; Figure 5 is
a plan of the steam slide valve; and Figure 6, a longitudinal section. In
Figures 1 and 2, a steam pipe F is shewn for admitting steam into the port e
in the back of the valve E; tho end of this pipe is faced true, so as to bear

page_text: against the back of the valve E (which is likewise faced truc) at e¹, so that
when the flange e" abuts against the back of the valve at e'; the parts may
thus be rendered steam-tight. A recess is cut or formed in the casing to
receive the flange e" of the pipe F. The interior of the pipe is bevilled off
at f, where it comes in contact with the valve back, so as always to have a full
open port at any point of the stroke of the expansion valve. A stuffing box F¹,
is formed in the back of the casing, through which the pipe F projects; a
shoulder is formed on the pipe for the packing. to press against, and is made
to bear. upon it by means of the gland F, which is formed with a flange and
knife edge or points f", f", for the bottom of the annular box Fs to rest upon,
and which is in turn pressed by the nuts 9, 9, on the screws 9', g', causing the
gland F to bear against the packing in the annular box F." By means of the
nuts the pressure may be increased or decreased at pleasure. The packing
may be made of india-rubber or other suitable clastic material. Or, instead
of packing in the annular box F, a helical spring may be used for the gland F
to bear against. The expansion valve E receives motion through the spindle G,
by means of the connecting rod G', which is jointed to it by the pin h; the
other end of the rod G' is jointed to the block G, by means of the pin h'.
This block is fitted in the short slot II, similar to the block D', and is likewise
capable of being moved in it to or from either end, as desired. This is effected
by means of the rods I and J; the rod I being jointed or attached to the pin a
(by which the rod D is jointed to the block D'); the other end of this rod is
jointed to a lever I', which is fixed on a rocking or weigh-shaft I; on the same
shaft another lever I³ is fixed at right angles to the lever I';. this lover is
connected by means of a rod I to a lever 1, centred or pivoted at i. The
upper end of this lever has a handle formed on it, and has a small lever
jointed to it at ; its end is of a T-shape. A rod is jointed to this lever
at ; the lower end of the rod is formed into a bolt passing through a
shackle j, fixed on the lever 1, and taking into notches 7, in the curve plate 1°.
A spring presses on the small lever i', forces down the bolt j into the
notches, thus keeping the lever I", the rods and levers I, 13, 13, 1, 1, pin a,
block D', and end of connecting rod D in any desired position. The block G²
is shifted in a similar manner in the short slot H by the rod J, jointed to it by
the pin ', by which the rod G is jointed; this rod is attached to the end of
the lever J', fixed on or formed in a piece with a tube J, through which the
shaft 12 passes.
Another lever J is formed or fixed on the tube J at right
angles, or nearly so, to the lever J'; a rod J' connects the end of the lever J³
to another hand lever J, pivoted or centred at i, and is similar to the lever 1°
previously described, and fixed in any desired position in a like manner. The

page_text: block G is shifted in the slot HI to give the necessary motion to the valve E,
so as to regulate the cutting off of the steam for the required expansion. The
block D' is shifted to either end of the slot D, so as to bring either of the
connecting rods B or B' into play, to move the valve D³ to a proper position
either for a forward or backward motion of the engine. The expansion may
be likewise regulated by the block D' being placed in any position between
the centre and ends of the link slot D. Figures 7 and 7° are respectively
section and plan of the steam pipe F.
By using valves of the construction described, a considerable amount of
friction is obviated on account of the steam valve being so formed as to allow
the exhaust steam to bear a pressure all round the valves, or nearly so, and
likewise because the rubbing surfaces are considerably reduced, and the area
of the steam-valve-face being mado much less as there is no eduction port
to cover.
Figure 8 is a longitudinal section of the cylinders, valves, and valve casing
of a pair of steam engines, with modifications of our improved valves and
steam pipe applied thereto; Figure 9 is a cross section of the same through
the steam pipe. To similar parts similar letters of reference apply as in
Figures 1 and 2; and as all the principal parts in Figures 8 and 9 were
described with reference to Figures 1 and 2, a particular description thereof
in respect of theso Figures is unnecessary. The backs of the expansion
valves E, E, aro bevilled in this modification, instead of being parallel as in
Figures 1, 3, 4, 5, and 6. When placed with their faces to their respective
cylinders an angular recess k, k, is thus formed between their backs; the
steam ports are formed in the back of each valve, as shewn by the dotted
lines in Figure 9, which ports correspond to similar ports ',, in the steam
pipe F, the lower end of which is formed of a wedge shape to fit the angular
recess, and make a steam-tight joint by bearing on the backs of the expansion
valves. The steam for both cylinders enters by the pipe F, and is distributed
through the respective ports to each valve. The pipe F projects as before
through a stuffing-box F', F', on the casing, and by screwing the gland F
down on the clastic packing the joint is made steam-tight. To the lower or
wedge-shaped end of the steam pipe a rod or bolt is attached, which
projects through the casing at ", and through the piece 4, india-rubber ring
, and disc, and is fastened by the nut 7, by which the necessary degree
of pressure can be put on the various valve and working faces.
Figure 10 is a section of the steam pipe F with its tapered or wedge-shaped
faces and ports ', . Figure 11 is another detached section of the steam
pipe, at right angles to Figure 10. Figures 12 and 13 are sections of a modi-

page_text: fication of the steam pipe F and stufling-boxes, taken at right angles to cach
other; in this case the bolt is done away with. The bolts or screws 7, 1, for
tightening the gland F and the upper gland, are made of sufficient length to
pass through the glands and flanges of both stuffing-boxes, and the necessary
pressure required to keep the angular faces in close contact is effected by
means of the stuffing-box F and gland F; the gland F.is forced against
the packing which abuts on the shoulder f, f', by the nuts l', l', being
screwed further on the screwed rods or bolts . The parts are stationary
and secured to the flanges of the stuffing-box already described by the
nuts on the screwed rods or bolts 7. The gland of the stuffing-box of
the permanent pipe is tightened by means of the nuts.1, 1. This stuffing-
box is for the purpose of keeping the junction of the pipes and F
steam-tight.
:
Figures 13 and 13b are sections of a modification of Figure 9; and
Figure 13 is a detached view of the steam pipe and hollow annular
cylinder or steam ways of Figures 13ª and 13b. E, E, are the valves, set as
in a locomotive with their backs facing each other; a short annular cylinder
E', with the steam pipe F entering its side at right angles, and cast in a pieco
with it or otherwise, is placed between them; the ends of this cylinder face
the backs of the valves. Moveable hollow pistons E, E, are inserted in the.
cylinder E', one in each end; these pistons are packed steam-tight, and have.
a helical spring Es inserted between them, so as to press both against the
backs of the valves, thus rendering them steam-tight. The steam is allowed
to pass from the annular space E to the inside of the cylinder E', through
the openings E between the hollow pistons, and thenco passes through them
and enters the backs of the valves E, E; in this arrangement the lap is on.
the inside of each steam valve. The exhaustion of the steam takes place past
the ends of the valves into the steam chest, and thenco to the condenser or
atmosphere. A projection E is attached or cast on the lower side of the
short cylinder or annular ring E', which. enters a socket E', for the purpose
of keeping it steady while the valves E, E, are in motion; in this arrange-
ment one or more ports in the valves and cylinder faces may be used.
Figure 1 is a modification of the last described valves and fittings applied
to a single engine, the steam port e being in the side of the expansion valve
instead of in the back; the cross section of this valve is triangular; one of
the faces is applied to the back of the steam valve D³ as before, the second m
back of the valve m¹ is inclined,
is horizontal or nearly so, while the third or
and fits into the exhaust steam chest, which is of a corresponding shape, and
which keeps its face up to the back of the steam valve by being pressed into

page_text: the angle formed by the back of the steam valve and angular side m', by the
hollow piston m², which is packed steam-tight in the short cylinder m³, which
is the termination of the steam pipe F where it joins the valve casing; it is
made of such a diameter as to admit a hollow piston, the opening of which
is of the same area (or nearly so) as the pipe F; the end of the piston
which is in contact with the side of the valve is faced so as to form with it a
steam-tight joint. The piston is pressed to the valve by means of a helical
spring m, inserted in the cylinder m³ between the piston m² and end of the
pipe F, against both of which it abuts, and thus presses the hollow piston
against the side of the valve, the port e being formed to correspond to the
hollow of the piston m³, and thus admit steam into the interior of the
expansion valve, similar to those previously explained.
Figure 15 is a modification of the link motion previously described in
reference to Figures 1 and 2; all the parts are the same with the exception
of the expansion valve connecting rod G', which is jointed to the centre of
the link C dircet, instead of being jointed to the sliding block G in the slot
H, whereby the extra hand-gearing rods and levers are dispensed with as
being unnecessary.
Figure 16 is a longitudinal section of a steam engine cylinder, with a
modification of our improved expansion valves fitted to a short slide valve;
K is the slide valve, having two ports n, n, in its face to correspond to similar
ports n,, in the face of the cylinder; this valve has a port n³ in the back
similar to the expansion valves before explained; K' is the expansion valve
fitted to the back of the steam valve, and is pressed upon by a hollow
cylinder m², as in Figure 14. The expansion valve has only one port which
corresponds with the port n in the back of the steam valve; this valve is for
cutting off the steam at any desired point. These valves may be worked by
any of the valve gearing before mentioned, by means of the valve spindles
D' and G; E' is the exhaust steam chest from which the steam may pass
either to the condenser or atmosphere.
Figure 17 is another modification similar to Figure 16, but without the
expansion valve, the hollow cylinder in this case pressing direct on the back.
of the steam valve.
Figure 18 is a sectional view of part of a steam pipe and short cylinder,
with hollow piston to press on the back of either valve, the pressure being
regulated by the nut o on the screwed rod o'; this nut presses down the end
of the lever o, which is fixed on a short shaft o³, passing through a stuffing-
box o in the side of the steam pipe F; on this shaft another short lever o
is fixed; to the end of this a rod is jointed, extending down the pipe and

page_text: into the short cylinder, where it passes through a plate or disc of until it is
caught by a collar o on the rod; this collar presses down the plate on to a
helical spring p, which presses down the hollow piston m² on the back of the
valve or valves. The rod after passing through the disc is slotted at p' to
receive a pin, which is fixed in a stud screwed in a boss p in the centre of
the hollow piston; this serves as a guide to steady the end of the rod, and at
the same time to allow the piston to move up and down as far as is necessary;
Figure 18 is a plan of Figure 18.
Figures 19 and 20 shew arrangements for lifting the slotted links C over
or along the blocks p³. The blocks in this arrangement are fixed on the
valve spindle rods without any yielding joint, and held steady by the rod p'
working through a boss on a bracket p³. The slotted link is moved up or
down by rods p and levers p', similar to the mode of moving the blocks
previously explained. The expansion valve is worked from a fixed pin 9 in
the slotted link, to which is connected a rod q', which extends in the direction
of the crank shaft B'; this rod q' is forked, and passes through or spans a
boss q on the shaft, and which boss and fork support the rod q' and keep it
steady; in this rod a pin 23 is fixed, to which is attached the rod q* for
working the valve.
Figure 21 is an arrangement of the doublo slotted link C, which is shifted
by rods and levers, and fixed by means of bolts and catch plates, similar to
those previously described when referring to the mode of shifting the slide
blocks in the slots of the links in Figures 1 and 2. In this arrangement
the link is shifted on the block to fit it for a forward or backward motion;
while to work or set the parts to work the expansion valve the block G is
shifted in the slot, and kept in any desired position by a small catch or pro-
jection formed on the handle L, sprung into notches L formed in a segmental
catch-plate L', attached to the reversing handle L, which is held by the
catch-plate L'; a rod L jointed to the block by a pin leads in a direction
toward the crank shaft B', which it spans in a similar manner to that referred
to in Figure 19; on a pin L', near the forked end of the rod L, another rod
L is jointed, which works the valve by being connected to the valve spindle
Ls at L.
Figure 22 is a longitudinal section of a steam engine with another modifi-
cation of our improved valves applied thereto; M is the steam valve with
two steam ports r, r, in each end through it; the cylinder has a corresponding
nnmber of ports 1, 1, 1, ³, two of which open into the steam ways or
passages to each end of the cylinder; N is the expansion valve, having a
like number in its face, which lies on the back of the steam valve. The rest

page_text: of the parts are the samo as already described, consisting of the short hollow
piston in a short cylinder, pressed down on the back of the valve N in which
the steam port is formed; steam is admitted through the hollow cylinders
into the valve N, and thence through either end of the steam valve M (accord-
ing to its position) and into the steam cylinder and propelling the piston to
the end of its stroke when the steam is liberated by the shifting of the valve,
and thus allows the steam to escapo through the exhaust ports s, s, or s¹, s',
into the exhaust steam chest, and thence it may be taken to the condenser
or allowed to blow into the atmosphere. The valves are worked by the
link motion as described, by using two steam ports; a very short stroko is
necessary.
Figure 23 is a plan of the expansion valve, shewing the double ports;
Figure 24 is an end view of the same; Figure 25 is a longitudinal section of
Figures 23 and 24.
Figure 26 is an end view of steam valve; Figure 27 is a plan of Figure
26, shewing the ports in the same; and Figure 28 is a sectional view of
Figures 26 and 27.
And having now described the nature of our said Invention, and in what
manner the same is to be performed, we declare that we claim,-
First, the construction, arrangement, and mode of working the valves of
steam engines in the manner herein-before described.
Second, the introducing of the steam direct from the boiler to the back or
sides of the valves of steam engines.
And, third, the working of the expansion valves in conjunction with the
cylinder valves of steam engines, by two excentrics connected to one or more
links.
In witness whereof, we, the said Thomas Charlton and William Turnbull,
have hereunto set our hands and seals, this Twenty-sixth day of
November, One thousand eight hundred and fifty-six.
THOMAS CHARLTON
rel