IMPROVEMENTS IN MEANS OR APPARATUS IN CONNECTION WITH STEAM ENGINES TO FACILITATE THE WORKING OF THE SAME EXPANSIVELY
Year: 1860

page_text: LETTERS PATENT to Henry Cartwright, of the Dean, Broseley, in the
County of Salop, Gentleman, for the Invention of "IMPROVEMENTS IN
MEANS OR APPARATUS IN CONNECTION WITH STEAM ENGINES TO FACILITATE THE
WORKING OF THE SAME EXPANSIVELY."
Sealed the 11th December 1860, and dated the 26th June 1860.
PROVISIONAL SPECIFICATION left by the said Henry Cartwright at
the Office of the Commissioners of Patents, with his Petition, on the
26th June 1860.
I, HENRY CARTWRIGHT, of the Dean, Broseley, in the County of Salop,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN MEANS OR APPARATUS IN CONNECTION WITH STEAM ENGINES TO FACILITATE.
THE WORKING OF THE SAME EXPANSIVELY," to be as follows:-
The improvements relate to the application of a valve in the passage to the
cylinder adapted when partly raised at the times desired, by the parts acting
therewith, to be fully closed by the action of the flowing steam, and thereby
to cut off the supply thereof, and then having a tendency to open, aided by
the eduction steam. The valves I use are of the character commonly called
flap valves; and I place such in the steam pipe, or between the working
steam valve and the nozzle or port of the cylinder. The hinged side of the
valve is next the entrance to the cylinder, and the free side or edge of the
valve is inclined in the opposite direction, so as to be capable of meeting the
induction steam. At the times desired the free edge of the valve is slightly
raised by a cam, or by other suitable means in the working of the engine,
when the current of the induction steam acts fully to close it against its seat,
and thereby for the time to shut off the communication between the supply of

page_text: steam to the cylinder. At the return stroke of the piston the tendency of
the valve is to open, and this tendency is aided by the force of the eduction
steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Cartwright in the Great Seal Patent Office on the
26th December 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
CARTWRIGHT, of the Dean, Broseley, in the County of Salop, Gentleman, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of June, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Cartwright, Her special licence that I, the said Henry
Cartwright, my executors, administrators, and assigns, or such others as I,
the said Henry Cartwright, my 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 "IM-
PROVEMENTS IN MEANS OR APPARATUS IN CONNECTION WITH STEAM ENGINES TO
FACILITATE THE WORKING OF THE SAME EXPANSIVELY," upon the condition
(amongst others) that I, the said Henry Cartwright, my executors or admi-
nistrators, by an instrument in writing under my, or their, or one of 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 I, the said Henry Cartwright, do hereby declaro
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
The improvements relate to the application of a valve in each passage to
the cylinder, adapted, when partly raised at the times desired, by the parts
acting therewith, to be fully closed by the action of the flowing steam, and
thereby to cut off the supply thereof, and then to have a tendency to open by
the eduction steam. The valves I use are of the kind commonly called flap

page_text: valves, and they close upwards, and when not in action lie in a horizontal or
nearly horizontal position, with their hinged sides next and generally close to
the respective nozzles of the cylinder. The free edges of these valves may lie
in rebates, by which they will be shielded from the induction steam, which
will then pass over them without interruption until the edge of either valve is
slightly raised. This raising I accomplish by a cam fixed upon a spindle, one
end of which passes through a stuffing box in the side of the valve box, and
carries a lever, which receives an alternating motion from some of the moving
parts of the engine. Upon the free edge of the valve being raised a portion
of the induction steam flows against the under side of the said valve, to raise
it to its seat. The steam thus shuts itself suddenly off from the cylinder
without the disadvantage of being wire drawn, and the piston is carried to the
end of its stroke by the expansive action of the steam in the cylinder. Upon
the return stroke of the piston the expansion valve falls by its own weight
into its open position, its descent being hastened by the eduction steam, the
cam having by this time alternated back out of the way of the returning
valve. In many cases, where engines are worked expansively, it is neces-
sary to have additional eccentrics for working the expansion valves, but my
expansion valves can usually be worked by the same eccentric which works
the reciprocating steam valve, of whatever kind such valve may happen to be.
I do not, however, limit myself to the use of such eccentric, as some steam
engines have their steam valves worked without an eccentric.
For engines which work in only one direction it will only be necessary to
have one cam upon each cam spindle, but in engines which reverse their
motion and work in both directions it will be necessary to have two cams
upon each spindle, for, if there were only one cam on each spindle, the said
cam being so fixed as to elevate the expansion valve at the proper time to
correspond to the stroke of the piston, then, upon the engine being reversed,
the cam would be depressed or out of action at the same period of the piston's
motion (supposing the cam to be worked from the same eccentric which works
the steam reciprocating valve). This defect is caused by the eccentric
travelling before the crank when the engine works in one direction, and the
crank travelling before the eccentric when the engine works in the reverse
direction, but if there are two cams on each spindle projecting on opposite
sides of it, one or other of the said cams will be in action at the proper time.
The cam on that side of the spindle next to the valve hinge is shorter than
the cam next to the free edge of the valve, the extremity of the said cam
being required to travel in an arc of smaller radius than the cam which acts
on the valve near its free edge. Where two cams are fixed upon each spindle

page_text: the expansion valves will be slightly elevated both at the stroke and return of
the piston, or when the steam is leaving the cylinder, as well as when it is
entering, but this slight elevation of the valve will present no material
obstruction to the eduction steam, especially as the steam with any amount of
strength will have escaped from the cylinder before the elevation of the said
valve takes place.
I will now describe my Invention with reference to the accompanying
Drawings.
Figure 1 is a side elevation of the cylinder of a horizontal steam engine
having my improved expansion valves applied thereto; Figure 2 is a section
of the same, and Figure 3 is an expansion valve shewn on a larger scale. The
same letters indicate the same parts in Figures 1, 2, and 3.
A is the slide valve; B the slide valve rod; C the piston; D', D, are the
expansion valves, which turn on hinges d', d'; E', E, are the spindles which
carry the cams e', e³, e³, e'. These spindles pass through stuffing boxes F, F,
and are worked by levers G', G³, fixed on their ends. By means of con-
necting rods H, H, the levers G', G, receive motion from the eccentric
which works the slide valve. I do not however confine myself thereto. In
many horizontal engines there is a lever between the eccentric and the slide
valve. This lever communicates motion from the eccentric rod to the slide
valve, and it may also give motion to the rods of the expansion valves. The
length of the said lever corresponds with the difference of level between the
eccentric and the slide valve. When the piston C is at the top of the cylinder,
as shewn by dotted lines in Figure 2, the eccentric, as is usually the case, will
be about a quarter of a revolution before the crank, and the slide valve con-
sequently at half stroke, and the levers on the cam spindles being actuated by
the eccentric will likewise be at half stroke, as shown by dotted lines, and the
expansion valves D', D³, will be in their lowest positions. As the eccentric
moves the slide valve A towards the left-hand extremity of its stroke, thus
admitting steam to the cylinder, the rods H', H³, levers G1, G2, and cams
e, &, e, e, assume the position shewn in the Drawing, and the expansion
valves D', D, will be raised from the rebates, as shown at Figure 8. The
valve D will thus be exposed to the induction steam, which, flowing against
its under side as indicated by the arrow, will carry it up into its seat and close
it, thus cutting off the communication between the cylinder and the induction
steam pipe. The piston will now be urged to the end of its stroke by the
expansive force of the steam in the cylinder, aided, if the engine is a con-
densing engine, by the vacuum on the other side of the piston. Upon the
return stroke of the piston the valve D will operato in a similar manner to

page_text: the valve D'. The position of the piston when the expansion valve comes into
operation will, of course, depend upon the degree of expansion with which the
engine works. In order to make the engine work with a greater or less
degree of expansion, the rods H', H, are connected to the levers G¹, G³, by
pins h, h, which pass through eyes in the ends of the rods H', H², and through
holes g, g, in the said levers, by which they are capable of adjustment nearer
to or further from their centres of motion. Thus when the rods are attached
to the levers near their centres of motion (the reciprocating motion which the
rods derive from the eccentric being the same the levers and cams will move
through a greater arc, and will consequently have a quicker action on the
expansion valves, which latter cut off the steam more quickly than when the
rods H', H, are attached to the levers G¹, G³, near their free ends.
The arrangement described may be modified as follows:-In place of the
holes g, g, the lever on each cam spindle is provided with a sliding piece.
These sliding pieces can have the ends of the rods H', ', jointed to them, and
the sliding pieces may be adjusted upon the said levers by set screws.
Figures 4 and 5, represent in side elevation and section respectively the
cylinder of a steam engine having my expansion valves applied thereto. The
said cylinder being in a vertical position and provided with the reciprocating
steam valves or cocks described in the Specification of Letters Patent, granted
to me bearing date the 2nd day of June 1855, No. 1263. Figure 6 is a
separate view on a larger scale of one of the expansion valves. The same
Jetters indicate the same parts in Figures 4, 5, and 6.
A', As, are the reciprocating valves by which steam enters and leaves the
cylinder; B', B, are rods which receive motion directly or indirectly from an
over-head eccentric, which motion they communicate to the valves A¹, A².
C is the piston which is here shewn at the bottom of its stroke and com-
mencing to ascend; D', D², are the expansion valves which turn on hinges d', d.
E', E, are spindles carrying the cams e', e³, e³, e'. The ends of the said spindles
pass through stuffing boxes F, F, and carry levers G1, G2, which by means of
the connecting rods H, H, receive motion from an arm I, carried by the
rod B¹. As the piston C ascends, and the eccentric on the crank shaft
moves the rods B', B, in order to open the reciprocating rotary valve A¹
to the full extent, the rods H', H, will have raised the levers G¹, G', to
the position shown by the dotted lines at Figure 4, and the expansion valves
and the cams which actuate the same will have assumed the position indi-
cated by dotted lines in Figuro 5. The valve D will thus be exposed
to the current of the induction steam, which flowing against its under side,
as indicated by the arrow, will carry it up into its seat and close it as shown

page_text: separately at Figure 6, thus cutting off the communication between the
cylinder and the induction steam pipe. The piston will now be urged to the
end of its stroke by the expansive force of the steam in the cylinder, aided, if
the engine is a condensing engine, by the vacuum on the other side of the
piston. Upon the return stroke of the piston the valve Ds will operate in a
similar manner to the valve D¹.
Figures 7, 8, and 9, represent in side elevation, section, and plan respectively,
part of the cylinder of a horizontal engine to which my improved expansion
valves are applied, the said cylinder being provided with the reciprocating
rotary valves described with reference to Figures 4 and 5. Figure 10 is a
separate view of one of the expansion valves. The same letters indicate the
same parts in Figures 7, 8, 9, and 10.
A is one of the valves by which steam enters and leaves the cylinder; B¹
is a rod which derives its motion from the eccentric and works the valve
A, and B is the rod which communicates motion from the rod B' to the valve
at the other end of the cylinder. C is the piston; D is one of the expansion
valves, and E is the spindle carrying the cams e, e, which work the said
valve; H' is a rod which receives motion from the excentric and works the
lever G on the spindle E, and Hs is the rod which communicates motion
from the rod H' to the lever on the cam spindle at the other end of the
cylinder.
Although I have only described my Invention as applied to a single cylinder
I would have it understood that my said Invention is applicable to engines
provided with two or more cylinders.
Having now described the nature of my Invention, and the manner in
which I carry the same into effect, I wish it to be understood that I do not
limit myself to the precise details herein-before described, as the same may
be varied without departing from the nature of my said Invention. But what
I claim is the adaptation or combination of means or apparatus in connection
with steam engines whereby the working of steam expansively may be facilitated
in manner substantially as explained.
In witness whereof, I, the said Henry Cartwright, have hereunto set
hand and seal, this Twenty-second day of December, in the year
of our Lord One thousand eight hundred and sixty.
my
HENRY CARTWRIGHT. (L.B.)