IMPROVEMENTS IN AND CONNECTED WITH VALVE MOTIONS AND CYLINDERS OF STEAM ENGINES
Year: 1882

page_text: LETTERS PATENT to Alexander Carnegie Kirk, of the firm of Robert Napier
and Sons, of Glasgow, in the County of Lanark, North Britain, for an
Invention of "IMPROVEMENTS IN AND CONNECTED WITH VALVE MOTIONS
AND CYLINDERS OF STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said Alexander Carnegie Kirk
at the Office of the Commissioners of Patents on the 30th August 1882.
ALEXANDER CARNEGIE KIRK, of the firm of Robert Napier and Sons, of Glasgow,
in the County of Lanark, North Britain, "IMPROVEMENTS IN AND CONNECTED
WITH VALVE MOTIONS AND CYLINDERS OF STEAM ENGINES
"
This Invention relates to the valve motions and cylinders of steam engines and
has for its objects to improve the construction and action of the valve motions, to
render the interiors of the cylinders more conveniently accessible especially when
as in some kinds of compound engines in which two cylinders are placed end to end
the covers or some of them cannot be conveniently removed, and to provide
efficient and convenient packings for the piston rod between cylinders thus
placed.
The improved valve motion to some extent resembles the "fixed-link" type of
link motion already in use for working the valves of steam engine cylinders, and it
is arranged to communicate to the valves a motion which is a combination derived
from the movements of the piston rod and of the connecting rod. The valve rod is
in each case connected to the link by a long rod and a joint block sliding on or in
the link and movable to either extremity according to the direction in which the
engines are to turn. The link is fitted so that it can rock on a pin at its middle
and is connected by the pin to a lever or other moving part deriving its motion
from the piston rod in such a way that the pin moves in the same direction as the
valve or nearly so. In this way a movement is obtained equivalent to the linear
advance of the valve, whilst the component of the valves motion which gives it
opening is derived from a pin on the connecting rod and is transmitted from that
pin by a lever centered at its middle on the pin and having one end connected by a

page_text: radius rod to a fixed point at one side whilst the other end is connected by a link
at the other side to a lever suitably formed or fixed on the valve-inotion link. The
valve-motion link is thus moved to and fro by one connection and made to rock by
the other connection, and the resulting motion of the valve is better in various
respects than what is obtained with existing valve gear not possessing objection-
able complexity, and is obtained without encumbering the shaft with eccentrics.
To allow of examining the interior of the cylinder or either side of the piston
without removing the end cover, a manhole is by this Invention, formed in the
side of the cylinder itself. This manhole is by preference made circular, and is
provided with a plug or cover made with a flange outside to form a joint, whilst
the inner side forms part of the internal surface of the cylinder and may indeed be
fixed in its place when the cylinder is being bored so as to be bored along with the
rest of the internal surface of the cylinder. The joint flanges may be curved con-
centrically with the cylinder but are by preference flat, the joint face on the outside
of the cylinder being formed on projecting parts where necessary. When the
cylinder is steam jacketed the plug or cover is fixed on the inner shell or cylinder
there being an opening large enough to introduce it in the outer shell or casing
which opening may be closed by an ordinary door.
For the purpose of packing the piston rod where it passes between the two
cylinders placed end to end a number of plates of brass or other suitable metal are
made of a horseshoe form and of uniform thickness; and each has combined with
it a tongue piece fitting between the jaws and pressed inwards by a spring held by
a cross piece fixed to the ends of the jaws. When the tongue piece is in position
the combination forms a piece having a central hole which fits the piston rod. Two
or more of the plates with their spring tongue pieces are combined together with
the tongue pieces in different positions; and a set of them is held between a flat
surface formed for them round the piston rod hole on the cylinder end or cover
and a flat ring accurately adjusted in position by means of screw studs or bolts.
Two sets of the plates are by preference applied between the two cylinders, one set
being in connection with each cylinder end or cover; and the two sets of plates
are enclosed in a common chamber into which steam from the intermediate
receiver or otherwise of suitable pressure is admitted. This improved packing
arrangement may be adapted for use in place of an ordinary stuffing box.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Carnegie Kirk in the Great Seal Patent Office on the
24th February 1883.
ALEXANDER CARNEGIE KIRK, of the firm of Robert Napier and Sons, of Glasgow,
in the County of Lanark, North Britain, "IMPROVEMENTS IN AND CONNECTED
WITH VALVE MOTIONS AND CYLINDERS OF STEAM ENGINES
"
My said Invention relates to the valve motions and cylinders of steam engines,
and has for its objects to improve the construction and action of the valve motions,
to render the interiors of the cylinders more conveniently accessible, especially
when as in some kinds of compound engines in which two cylinders are placed
end to end, the covers or some of them cannot be conveniently removed, and
to provide efficient and convenient packings for the piston rod between cylinders
thus placed.
My improved valve motion to some extent resembles the "fixed-link" type of
link motion already in use for working the valves of steam engine cylinders and
it is arranged to communicate to the valves a motion which is a combination
derived from the movements of the piston rod and of the connecting rod. The
movement derived from the piston rod is equivalent to the linear advance of the
valve, whilst the component of the valve's motion which gives it opening is derived
from the connecting rod, and the resulting motion of the valve is better in various
respects than what is obtained with existing valve gear not possessing objectionable
complexity, and is obtained without encumbering the shaft with eccentrics.
To allow of examining the interior of the cylinder or either side of the piston
without removing the end cover, a manhole is by my Invention formed in the
side of the cylinder itself.
For the purpose of packing the piston rod where it passes between two cylinders
placed end to end two or more plates of brass or other suitable metal are made
of a horse-shoe form and of uniform thickness and each has combined with it
a tongue piece fitting between the jaws and pressed inwards by a spring connected
to the jaws. The plates are combined together with their tongue pieces in different
positions; and a set of them is held between flat surfaces formed for them round
the piston-rod holes in the two cylinder ends or covers. Or there may be separate
sets of the plates one for each cylinder each set being held between the flat surface
formed on the cylinder cover and a flat ring accurately adjusted in position by
means of screw studs or bolts attaching it to the cylinder; or the adjustment may
be applied by screws or otherwise between the two rings so as to set them more
or less apart. The space between the cylinder ends and containing the packing
plates is enclosed to form a common chamber into which steam from the inter-
mediate receiver or otherwise of suitable pressure may be admitted. This improved
packing arrangement may be adapted for use in place of an ordinary stuffing box.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append two sheets of explanatory drawings
to be hereinafter referred to and representing modifications of my improved
apparatus.
Figure 1, on sheet 1, of the accompanying drawings is an end elevation showing
a modification of my improved valve gear as applied to a set of inverted-cylinder
marine engines; and figure 2, is a diagram showing a slightly varied modification.
Figure, 3, on sheet 2, is a horizontal section and figure, 4, is a sectional elevation
showing my improved arrangement for giving convenient access to the interior
of a steam engine cylinder, a different application of which is shown in vertical

page_text: and horizontal section in figures, 7, and 8. My improved packing for piston rods
is shown in figure, 4, and in sectional plan in figure, 5, whilst figure, 6, represents
one of the packing plates separately. In these drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
In the valve gear shown in figure, 1, the valve rod, 10, receives its motion
through a connecting rod, 11, which has its lower end jointed to a block fitted
to slide in a curved valve-motion link, 12, and the reversing or other alteration
of the valve action is effected by shifting the block of the connecting rod, 11,
along the link, 12, by means of a rod, 13, connected to the rod, 11, and to a
lever, 14, on a reversing shaft as is done with ordinary "fixed-link" valve motions.
The link, 12, is centered on a pin, 15, which receives an up and down motion from
the main piston rod, 16, such motion being, in this example conveniently given
through the air-pump lever, 17, connected to the piston rod, 16, by the usual
links, 18, and having the centre pin (or journals) 15, carried in bearings in a
suitable position upon it. The motion thus derived from that of the piston rod, 16,
and which is invariable, is compounded with a motion drived from the swinging
or vibrating of the main connecting rod, 19. In order that the motion derived
from the swinging or transverse movement of the main connecting rod, 19, may
not be undesirably affected by the up and down or longitudinal movement of that
rod, it is communicated through an adaptation of a well known "parallel motion
the rod, 19, having jointed on a pin, 20, fixed in it a lever, 21, one end of which
is connected by a radius rod, 22, to a centre pin fixed on the framing, whilst the
other end is connected by a rod, 23, to an arm, 24, formed on the valve-motion
link, 12. By these connections a rocking motion is imparted to the link, 12, and
causes that link to impart to the valve rod, 10, a motion depending on the
position of the block of the connecting rod, 11, in the link, 12, and which motion
is compounded with that caused by the rocking of the lever, 17, and derived from
the motion of the main piston rod, 16.
"
In the modification shown in figure, 2, my improved valve motion is arranged to
suit a valve placed above the main shaft of the engines as is often the case with
the high-pressure valve of a set of compound engines. The valve rod, 10, and the
direction of motion of the valve are a little inclined, and the valve-motion link, 12,
is arranged so as to be correspondingly inclined when in its middle position the
arm, 24, of the link being then vertical. The link, 12, may be carried on a pump
lever (17) as in the first modification, or a special lever, 17, may be provided to
carry and move it.
The manhole for giving access to the interior of the cylinder, 26, and shown in
figures 3 and 4, is by preference made circular, and is provided with a plug or
cover, 27, made with a flange outside to form a joint, whilst the inner side forms
part of the internal surface of the cylinder, 26, and may indeed be fixed in its place
when the cylinder is being bored so as to be bored along with the rest of the
internal surface of the cylinder. The joint flanges may be curved concentrically
with the cylinder but are by preference flat, the joint face on the outside of the
cylinder being formed on projecting parts where necessary. When the cylinder is
steam-jacketed as shown in the case of the cylinders 28, figures, 4, 7, and 8, the
plug or cover, 27 is fixed on the inner shell or cylinder, 28, there being formed an
opening large enough to introduce it in the outer shell or casing, 29, which opening
may be closed by an ordinary door, 30.
In my improved piston-rod packing arrangement, shown in figures, 4, 5, and 6,
a chamber, 31, is formed between the bottom end, 32, of the high-pressure or upper
cylinder, 26, and the top end, 33, of the low-pressure or lower cylinder, 28, this
chamber being provided with, by preference, two doors, 34, placed opposite each
other to give convenient access for examining and adjusting the packing. The
cylinder ends or covers, 32, 33, are formed with the usual projecting necks 35, 36,
for the piston rod 16, to pass through and be guided by; and the outer ends of
these necks are formed with flat surfaces made as truly as possible at right angles
to the axis of the cylinders. Between the flat surfaces of the cylinder necks, 35, 36,

page_text: there are placed four packing plates, 37, one of which is shown separately in figure, 6,
these plates being made each with parallel faces and of an aggregate thickness
as nearly as possible equal to the space between the necks, 35, 36. Each packing
plate is made with its larger part, 37, in form of a horse shoe and with a smaller
part or tongue, 38, fitting in between the jaws of the larger part, whilst the internal
bearing surface to fit upon the piston rod is made one half on the larger part, 37,
and the other half on the tongue, 38. The parts 37, 38, are pressed into contact
with the piston rod by a blade spring, 39, which is attached to the larger part, 37,
by screw studs and bears on the outer end of the tongue, 38. The four plates, 37,
are combined together in different positions as shown in figures, 4, and 5, and are
prevented from shifting round by a flange, 40, on one of the covers, 34, which
Blange engages with notched projections suitably formed on the several packing
plates. The springs, 39, are adjusted just sufficiently to keep the bearing surfaces
of the packing plates in contact with the piston rod, 16, and as the plates are free
to move laterally there can never be any undue lateral pressure on the piston rod
or on the packing, so that steam tightness can be secured without excessive
friction.
Having thus particularly described my said Invention and the manner of per-
forming the same I have to state that I do not restrict myself to the precise details
herein described or delineated but that what I believe to be novel and original and
claim as the Invention secured to me by and in terms of the hereinbefore in part
recited Letters Patent is:-
1. The combination of parts forming an improved valve motion the essential
feature of which is the imparting of motion derived from the main connecting rod
through a compensating lever and radius rod so as to rock a curved link centered
on a pin having motion derived from the piston rod, substantially as hereinbefore
described.
2. The constructing of a manhole in the side of a steam cylinder substantially as
and for the purposes hereinbefore described.
3. The arranging or combining together of the parts of piston-rod packing
apparatus substantially in the improved manner hereinbefore described.
In Witness whereof I, the said Alexander Carnegie Kirk, have hereunto set
my hand and seal this twenty-first day of February in the year of our
Lord One thousand eight hundred and eighty-three.
Witness
EDMUND HUNT
Patent Agent
Glasgow
ALEXANDER. C. KIRK (L.S.)