AN IMPROVED METHOD OF MAKING AND WORKING LOCOMOTIVE AND OTHER STEAM ENGINES
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAM PARKIN, on behalf of myself and ELISHA WYLDE, both of Liverpool,
in the County of Lancaster, Engineers, send greeting.
WHEREAS Her most Gracious Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date. at West-
minster, the Twelfth day of November, in the fourth year of Her reign,
did give and grant unto us, the said Thomas William Parkin and Elisha
Wylde, our exors, admňors, and assigns, Her special licence, full power,
sole privilege and authority, that we, the said Thomas William Parkin and
Elisha Wylde, our exors, admors, and assigns, and every of them, by our-
selves, or our deputy or deputies; servants or agents; or such others as we,
the said Thomas William Parkin and Elisha Wylde, our exors, admors, or
assigns, should at any time agree with, and no others, from time to time.
and at all times thereafter during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend, within that part of the
United Kingdom of Great Britain and Ireland called England, the Dominion
of Wales, and Town of Berwick-upon-Tweed, and also in all the Colonies
and Plantations abroad, our Invention of "AN IMPROVED METHOD OF MAKING
AND WORKING LOCOMOTIVE AND OTHER STEAM ENGINES," in such manner as to
us, the said Thomas William Parkin and Elisha Wylde, our exors, admors,
or assigns, or any of us, should in our discretion seem meet, and that we, the
said Thomas William Parkin and Elisha Wylde, our exors, admors, and,
assigns, should and lawfully might have and enjoy the whole profit, benefit,

page_text: commodity, and advantage from time to time coming, growing, accruing, and
arising by reason of our said Invention for and during the term of years
therein mentioned; in which said Letters Patent there is contained a proviso
that we, the said Thomas William Parkin and' Elisha Wylde, should cause a
particular description of the nature of our said Invention, and in what manner
the same is to be performed, by an instrument in writing under our hands and
seals, or under the hand and seal of one of us, to be enrolled in Her Majesty's
High Court of Chancery within two calendar months. next and immediately
after the date of the said in part recited Letters Patent (reference being
thereunto had, may more fully and at large appear).
NOW KNOW
Thomas Will that compliance with the said proviso; I, the said
Parkin, on behalf of myself and Elisha Wylde, do hereby
declare the nature of our said Invention, and the manner in which the
same is to be performed, are particularly described and ascertained in 'and
by the following description thereof (that is to say)
Our Invention consists,
Firstly, in moving the slide valve without the use of the eccentrics, in order
that it may open almost instantaneously at the time the engine is passing its
yukarı da sev
centre.
!
Secondly; in constructing the slide valve, so as almost wholly to get rid of
the immense pressure of steam which acts upon: slide. valves of the present
construction,tend at the same time to give a free passage for the waste steam
throughout the whole of the stroke.
Thirdly, in constructing the regulator or throttle valve so as to admit.steam
to one of the cylinders only, or to both cylinders at the same time.
Fourthly, in slightly increasing the machinery for moving the slide valve,
so as to cause the steam to work in the cylinders expansively; in order to save
fuel.
Я
And, fifthly, in machinery by which the action of the steam is reversed, and
made to act against the piston before instead of behind it, in order! that the 3
driving wheels may drag upon the rail and retard and almost instantaneously
stop the motion of the engine.
'
The following is the manner in which the slide valve is moved without the
use of the eccentrics:-We-fix a lever on the cross, head, which lever works
in a link connected to a 'second lever, which is fixed on a shaft or weigh bar 8
across the engine, whereby a rocking motion is produced. On the other end
of this weigh bar we fix a double lever,carrying studs, above and below.the
centre of the said. shaft or weigh bar for the tappett forked frod to work upon.
We attach one end of this rod; by a working joint to a fourth lever fixed on

page_text: the weigh bar, which gives motion to the: slide valve at each succeeding return
of the cross head to the extremity of its stroke, and we so arrange the lovers
that the slide valve is always wide open at the period of the engine passing. its
:: centre instead of being. shut, as by the eccentric-motion; by- which arrangement
-the full power, of the steam is made to act. upon the piston at this juncture,
the waste steam passing out through the open slide valve, and thereby prevents
any reverse pressure-by such waste steam or compressed air being pent up
f-sufficiently to oppose the progress of the piston to the other end of the cylinder.
The slide: valve always remains wide open-except at the moment of its revers-
ing its position, which is only; one half. the time occupied by the piston in
performing the same distance.
.i."
To
As to the second part of our.Invention, we construct the slide valve in
the following manner: We use a hollow ring which works backwards and
forwards between two surfaces, the bottom one being the cylinder facing, and
the top one a moveable plate having, the 'eduction passage, or, when the side
valve is made to work in the same direction as the piston, the steam passage
thro' its centre. : The pressure upon the. top of the valve is by this mode
removed; and the slide valve shaving no top, the.eduction passage is left quite
-free, the waste.steam not having any tendency to lift the slide valve from its
seat. We leave the hollow of the ring sufficiently long to allow the eduction
passage to be left open when the steam passage is closed, and vice versa.
prevent the escape, of the steam between the slide valve and the top plate, and
jalso, round-the edges of the plate, we let the plate into a square stuffing' box,
which must be packed and kept tight by a square. ring, which we press upon
the packing by set screws;: which.pass through à flanche fixed in the steam box
immediately above the ring, the plate. being kept down and its weight sup-
ported by four-set screws passing through the said flanche. This may also
be accomplished by planeing a recess round: the middle of the top edges of the
hollow ring-forming, the slide valve, into which we put a quare ring, which is
kept up to the top. plate (which will be a fixture.). by "springs placed under it
made sufficiently strong: to resist the pressure of the steam whilst the slide
valve is passing over the steam passage.
As to the, third part of our Invention, we construct the regulator or throttle
valve in manner, following (that is to say):-The valve is a flat surface,
having a passage thro' it at the distance of one passage from one end; when
the valve is moved to the starboard the larboard passage on the seat is opened
to the cylinder, and when moved to the, larboard the starboard passage on the
seat is opened, and the passage in the valve is brought over the larboard
passage on the seat, and, consequently, both passages will be opened.to their

page_text: respective cylinders, there being separate steam pipes connected to each cylinder
immediately underneath the seat of the throttle valve or regulator. By
opening the regulator to the larboard cylinder (the geared side) till one stroke
is made the tappetts of the starboard engine will have assumed their proper
position, and by turning the handle of the regulator to the reverse side the
steam will be admitted into both cylinders at one time. The handle of the
regulator will be in a vertical position while the regulator is closed-will
incline to the larboard side when the regulator is open to one cylinder, and
to the starboard side when the regulator is open to both cylinders, one half
the gears is by this mode dispensed with and the engine is more easily
managed.
.
"
As to the fourth part of our Invention we work the steam in the cylinders
expansively by increasing the machinery for moving the slide valve in manner
following:-We make two slots in the bottom of the link, in which the cross
head herein-before mentioned works, in which the two bell crank levers work
.on pivots. We fix to the inside framing of the engine a roller between these
two levers, being a fulcrum for the levers to act against when alternately
pressed down by the roller (attached to the lever on the cross head), which
works in the link passing over them. This causes the link to advance suffi-
ciently to close the slide valve, or, in other words, to cut off the communication'
between the boiler and cylinder.
As to the fifth part of our said Invention, to reverse the action of the steam
we place a handle on one side of the foot plate, which we connect to a bell
crank lever connected by a link to the tappett rod. This handle should be
secured by a spring guard, and when in a vertical position the tappett rod will"
be entirely out of gear, when it inclines forward it will be in gear for going
either forwards or backwards, and when it inclines backwards the tappett rod
will be lifted on to the stud on the third lever above the centre of the shaft
connected with the link on the other side, which will stop the motion of the
engine almost immediately, as the steam will be admitted into the cylinder
before instead of behind the piston, which will effectually drag the driving
wheels.
And the manner in which we carry this our Invention into effect is shewn
by the Drawings hereunto annexed, which are to be taken to form a part of
this our Specification, and by the explanation of the same as herein-after
ontained. Figure One in the Drawing of the locomotive engine is the lar-
board side elevation of an engine. Figure Two the top view of the engine,
and Figure Three the starboard side of the same. The cylinders and steam
chests in Figures One and Three are sections, and shew the construction of the

page_text: slide valve.
Figure 4, top view of the regulator
Figure 5, a section of the
end elevation of the regulator. Figure 6, machinery used in cutting off the
steam, so as to cause it to work expansively. Figure 7, the top view of the
slide valve. Figure 8, a locomotive engine, with the outside framing broken
away so as to shew the machinery. The following letters refer respectively to
the same. parts in each of the before-mentioned Drawings (that is to say) :-
a, the cross head, which works by means of the lever 6 in the link c. d, a
second lever fixed on the weigh bar or shaft e, across the engine. f, the third
lever fixed on the other end of the weigh bar e, carrying the studs g, above
and below the centre of the said weigh bar or shaft, upon which studs the
tappett forked rod works. h, the tappett forked rod. i, the working joint of
the tappett forked rod and the fourth lever k, which lever. is fixed on the
weigh bar l. m, the hollow ring used as a slide valve. n, the moveable
plate. o, a square stuffing box, which is to be packed, and is kept. tight by
the square.ring p.
9, a square ring fitted to a planed recess in the slide valve
r in Figure 6. The bell crank levers, working on pivots in the slots made in
the link c, against the roller s, which roller is fixed on the inside framing of
the engine. These bell crank levers are pressed down alternately by the
lever b-passing over them. t, Figure One, the handle by the side of the foot
plate, connected, as shewn in Figure One, to the bell crank lever (u).. v, in
Figure 5, the larboard passage to the cylinder; w, the starboard passage;
x, the hollow
passage
in the throttle valve. Figure 9 is a section of the side
elevation of a cylinder, and nozzle of a marine engine, and Figure 10 the end
elevation of the same.. a, the slide valve, which is of the same construction as
the valve for the locomotive engine, except that we use two valves instead
of one, and prefer admitting steam through and exhausting round it instead of
through it, as with the locomotive engine. 6 are the steam passages, c the
steam pipe, and d the eduction pipe. In engines of this construction we
extend the length of the side levers p, to the centre of the valve spindle v,
and we fix the roller w at the end of it, which roller travels in the link m,
which link is made alternately to open and shut the slide valves at the ter-
mination of each stroke by means of the forked lever f, the top of which lever
is connected with the top ends of the rods of the link m. by the cross head n,
and the bottom to the valve cross head e, by means of a fork, which we made
so as to work upon the studs of the said cross head e. o. are guides for the
said link rods m to work through, which guides we fix in perpendicular lines
on to the framing of the engine. 2 are, two pillars, which we fix on to the
cylinder cover to carry the shaft h, to work the valves by hand, which we
accomplish in the following manner:-The starting lever g is keyed on to the

page_text: end of the shaft, h; which works in the pillars
is another ilever keyed on
to the shaft, one end of which we attach by a pin joint to the top of the said
cross heade, and thus when the fork lever f. is: detached from the studs of, the
said cross, head by raising or falling the starting.clever the valve is
moyed to any position that may be required..kista balance, weight attached
to the shaft h; quis the cylinder, r.the piston, the piston: rod;rt the piston
cross head and the nozzle.
fin
....We claim the construction of the slide valve, being a hollow ring through
which the steam is either admitted or exhausted:
d.
And we also claim the means; used for keeping the said slide, valvei steam-
Funny livin»!st:
tight.
.
We also claim, the combination of the machinery for moving the valve,
especially the combination of the machinery; for moving the said valve so as
to work the steam expansively. **
We claim also the construction of the regulator or throttle valve,, by which
steam is admitted to either cylinder, only or to both cylinders at the same
time.” ………, ato
"And, lastly, we claim the combination of machinery for moving, the slide
valve, so as to cause the steam to enter the cylinder before instead of behind;
and make it act against the piston.
In witness whereof, I, the said Thomas William Parkin, have hereunto
set my hand and seal, the Twelfth day of January; in the year of our
Lord One thousand eight hundred and forty-one