IMPROVEMENTS IN STEAM ENGINES
Year: 1865

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN STEAM ENGINES." - A communication from abroad
by George Bender Whiting, of Washington City, and Thomas Fitch
Rowland, of Brooklyn, New York, both in the United States of
America.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
December 1865.
I, WILLIAM CLARK, of 58, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
These improvements consist, first, in making a cylinder for a reciprocating
steam engine with a fixed central cylinder trunk for the steam chest which
communicates with steam and vacuum chambers, which are made in one or
both of the cylinder heads as the case may require, the trunk having steam
ports leading into the cylinder and fitted with a balanced piston valve, which
is operated by any of the usual methods, their object being to diminish the
capacity of the passages leading from the steam ports to the cylinder to the

page_text: least possible space and reduce the weight and bulk of the engines, at the
same time providing the engine with an equilibrium valve; and, secondly, they
relate to an adjustable eccentric, by which an accurate and reliable cut-off and
reversing motion for steam valves of every description is obtained, which
consists in having a gear wheel of suitable dimensions fixed on the crank shaft
and working into another gear wheel of the same pitch and diameter, which
is made or secured on the circumference of a cylinder which rotates in suitable
bearings and encloses a system of gear wheels, disc, and an adjustable wrist
pin in such combination as to enable the operator to adjust the latter while
the engine is in motion, from the position which would cause the valve to
follow the furthest through any intermediate point of cutting off to that
position which would reverse the engines, and through the intermediate and
extreme points of cutting off in the reverse direction.
To enable others skilled in the art to make and use these improvements, I
will first describe the construction, arrangement, and operation embraced in
the first part, and then proceed to the second, reference being had for the first
to Sheet 1 of the accompanying Sheets of Drawings, in which Fig. 1 is an
end elevation of the piston cylinder of a reciprocating steam engine, and
Fig. 2 a central longitudinal vertical section of the same; and for the second
'to Sheet 2, in which Fig. 1 is a side elevation of the frame or pillow block,
showing the adjustable eccentric casing or cylinder and its connection with
the crank shaft of a steam engine; Fig. 2, a horizontal section taken in the
plane of the line x, x, Fig. 1, through the eccentric cylinder; Fig. 3, an
elevation of the eccentric cylinder in the direction indicated by red arrows in
Fig. 1; Fig. 4, a section through the eccentric cylinder in the plane of
the line y, y, Fig. 8; Figs. 5, 6, and
are detail views of the eccentric cylinder
and connecting parts thereof, with the valve stem of the engine. The cylinder
is constructed without the usual valve face, steam ports, and steam chest, but
has substituted in their place a fixed central cylinder trunk A, the axis of the
trunk coinciding with the axis of the cylinder. The trunk A is made with
suitable steam ports a, b, which communicate with the cylinder B, B, and is
fitted with a balanced piston valve C. One cylinder head D is made hollow
and divided into two chambers E and F; E is the steam chamber, the steam
entering through the induction opening G, as shown by arrows; F is the
exhaust chamber, the steam passing out through the eduction opening H.
One end of the trunk is made with a surrounding case, which is subdivided
into two or more compartu.ents or passages c, c, d, d, e, e, f, f', which open
into the trunk; the passages c, d, e, f, communicate with the steam chamber E,
while passages, d', c', f', lead into the cylinder B, B. The trunk A, A,

page_text: is secured to the cylinder head D by flanges g, g', which close the steam and
vacuum chambers E, F, from the cylinder when the valve C covers the ports
a, b. To allow for the variation of expansion of the cylinder and trunk, and
to facilitate the adjustment and removal of the head I, one end of the trunk
A, with the steam port b, is made in a separate piece and secured by the
flange h to the cylinder cover I, making a vacuum-tight joint, and is connected
with the other part of the trunk by the tongue and groove i, the tongue being
secured to flange h by a suitable number of webs j,j; the end of the
main portion of the trunk serves as a margin for the port b, so that the steam
lead will not be affected by the variation which may occur in the length of the
trunk by expansion or the adjustment of the cylinder head I. The valve C
is made a hollow cylinder open at each end, and having the required cro-s
area through its whole length, which serves as an exhaust passage from the
steam port 6 to the vacuum chamber F. The annular space J, J, is used as
a steam chamber in common with the stean chamber E, being united by
passages c, d, e, f, as above described. The valve C is fitted with a set of
metallic packing rings k, l, for each steam port, the outside ring of each set
being made in two parts as is usual, but to prevent any liability of variation
on the wearing surfaces of the rings m, n, and o, p, while passing the ports
a, b, they are united with a tongue and groover; grooves 8, s, are likewise
made on the outer surfaces of the inner rings, and the inner surfaces of
outer rings with tongues which fit the grooves 8, 8, and secure the rings to
the valves. The rings are adjusted by any of the usual methods in use. The
valve is fitted with a stem t, which is secured to boss u, the stem passing
through the stuffing box v, and unites with the proper connections for receiving
the motion required. The piston K, K, is made annular and fitted as in the
usual manner with metallic packing rings on the circumference; it is like-
wise fitted with metallic packing rings a working on the trunk A; w, w,
are the piston rods, also fitted in the usual manner.
Operation. The steam being admitted to the annular steam chamber J, J,
as above described, and the port a opened on the steam side, the steam enters
the cylinder behind the piston through the passages c, d, e, f', while the
port b is opened on the exhaust side, the steam passing out of the cylinder
B, B, through the valve C into the exhaust chamber F. When steam is
taken on the opposite side of the piston and the port a opened on the exhaust
side, the steam passes out through the passages c, d, e, f, into the exhaust
chamber F, and out of it through the eduction opening H, as indicated by
arrows.
•
The description of the second part of the present improvements will now

page_text: be given, reference being had to the Plate of Drawings showing the same, as
herein-before stated. A in the Drawings represents a spur gear of a con-
venient diameter and suitable proportions to do the work required, and secured
to the crank shaft B; C represents the cylinder of an adjustable eccentric of
a convenient size and form to enclose the several parts herein-after specified.
On the circumference of the cylinder C is a spur gear of the same pitch
diameter as the one keyed to the shaft, and by means of which the cylinder
is revolved. The cylinder C is made with one fixed head a and one movable
head b; the fixed head a has an oblong rectangular slot c through it; the width
and length of the slot c depends upon the size of the wrist pin d and the
required throw of the valve; the centre line of the slot c lengthwise to be at
a distance from the axis of the cylinder equal to that of the lap and lead of
the valve. The length of the slot c determines the external diameter of that.
section of the cylinder C which is used as a journal, and upon which it
revolves. The wrist pin d is made with a rectangular T head e, and rests in
a block f, which is fitted in the slot c in the head a, and is made so as to be
capable of moving from one end of it to the other, the pin d projecting out-.
side the head a a sufficient distance to connect with the valve stem or valve.
stem link. A disc g of suitable proportions is made to fit the inside of the.
cylinder C at h. Upon the face of this disc are two segmental lugs i, i,
Fig. 5, forming a groove between them for the T head e of the wrist pin d to
work in, and serving as the means of communicating motion to it. Two
internal gears of the same pattern, the length and pitch of the teeth depending
upon the work to be performed, are fitted to the largest inside diameter of the
cylinder C. One of the gears; is clutched with the disc g; the other
gear k is fixed to the cylinder C. One or more intermediate twin gears I, I,
m, m³, n, n, o, o¹, see Fig. 4, work into the internal gears j, k, and are placed
equi-distant from each other. Each twin gear is pivoted upon its mate, as shown
in Fig. 4. The intermediate twin gears are kept in their relative positions and
in contact with the internal gears j, k, by two pinions p, q, having the same pitch
diameter. One of these pinions p is made on or fixed to the sleever; the
other pinion, q is secured to the spindle s, which is fitted into and made to turn
with the sleeve r. The spindle s projects beyond the sleeve r a sufficient
distance to receive a lever gear or a hand wheel t, as may be desired. The
intermediate twin gears 1, l, m, m³, n, n³, o, o', and pinions p, q, are kept
in place by the movable head b, which is secured by bolts or otherwise
to the cylinder C. The sleeve r of the pinion p is fixed to the bracket u,
which is secured to the frame or pillow block D, while the movable head b,
being fitted on the sleever, revolves upon it as a journal. When the

page_text: arrangement of the engine admits of but a short connection between the
éccentric and valve stem, as represented in this case, to avoid the variation
of the lead at the opposite ends of the stroke consequent upon the
obliquity of short connections, the yoke E is used in combination with the
eccentric wrist pin d working in slides and secured to the valve stem r, as
shown in Figs. 2, 3, and 6. With this combination the lead of the valve
will be the same on either side at any point of cutting off, whether the
engine is moving either forward or backward. If it is required to make an
eccentric for the valve having less lap in proportion to the throw than the one
represented in this case, or to make an eccentric which can be reduced to a
dead centre, it may be constructed as shown in Fig. 7, the wrist pin & at the
part w being made rectangular and fitted to work in the slot Ċ. The head e
of the pin d, which being made as large as the case will adimit; has a groove *
on the inside at right angles to the slot c in the cylinder C. A pin y having
a T head is pivoted on the disc g, the T head a working in groove x.
Operation. With the cylinder C at rest, by turning the pinion q by means
of the hand wheel t, or its equivalent, the intermediate ġears l; m, n, o, are
turned upon their twins l', m³, n¹, o¹, which also turns the internal gear- j and
disc 9₁ the T head of the wrist pin d being clutched with the disc g is turned
with it, forcing the wrist pin d along the slot-c. The operation being the
same with the cylinder in motion, the wrist pin & can be moved to any point
in the slot c, varying the cut off or changing the direction of the engine
accordingly, while the wrist pin d, by the combination, is firmly sustained in
any position in which it is placed.
It may be here remarked, in conclusion, that the improvements constituting
the two parts of the above description may be used separate from each
other, or all in one and the same engine, the operation of each part being
entirely independent of the other.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
22nd June 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of December, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her

page_text: reign, did, for Herself, IIer heirs and successors, give and grant unto me, the
said William Clark,. Her special licence that I, the said William Clark, my
executors, administrators, and assigus, or such others as I, the said Williamı,
Clark, ny 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," a communication to me from abroad by George Bender
Whiting, of Washington City, and Thomas Fitch Rowland, of Brooklyn,
New York, both in the United States of America, upon the condition
(amongst others) that I, the said William Clark, my executors or adminis-
trators, 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 William Clark, do hereby declare 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, reference being had to the two Sheets of Drawings hereunto.
annexed, and to the letters and figures marked thereon (that is to say) :-
These improvements consist, first, in making a cylinder for a reciprocating
steam engine with a fixed central cylinder trunk for the steam chest which
communicates with steam and vacuum chambers, which are made in one or
both of the cylinder heads as the case may require, the trunk having steam.
ports leading into the cylinder and fitted with a balanced piston valve, which
is operated by any of the usual methods, their object being to diminish the
capacity of the passages leading from the steam ports to the cylinder to the
least possible space and reduce the weight and bulk of the engines, at the
same time 'providing the engine with an equilibrium valve; and, secondly,
they relate to an adjustable eccentric, by which an accurate and reliable
cut-off and reversing motion for steam valves of every description is obtained,
which consists in having a gear wheel of suitable dimensions fixed on the
crank shaft and working into another gear wheel of the same pitch and
diameter, which is made or secured on the circumference of a cylinder which
rotates in suitable bearings and encloses a system of gear wheels, disc, and
an adjustable wrist pin in such combination as to enable the operator to

page_text: adjust the latter while the engine is in motion, from the position which would
cause the valve to follow the farthest through any intermediate point of cutting
off to that position which would reverse the engines, and through the
intermediate and extreme points of cutting off in the reverse direction..
To enable others skilled in the art to make and use these improvements, I
will first describe the construction, arrangement, and operation embraced in
the first part, and then proceed to the second, reference being had for the first to
Sheet 1 of the accompanying Sheets of Drawings, in which Figure 1 is an end
elevation of the piston cylinder of a reciprocating steam engine, and Figure 2'
a central longitudinal vertical section of the same; and for the second to
Sheet 2, in which Figure 1 is a side elevation of the frame or pillow block,
showing the adjustable eccentric casing or cylinder and its connection with
the crank shaft of a steam engine; Figure 2, a horizontal section taken in the
plane of the line a, a, Figure 1, through the eccentric cylinder; Figure 3,
an elevation of the eccentric cylinder in the direction indicated by red arrows
in Figure 1; Figure 4, a section through the eccentric cylinder in the plane
of the line y, y, Figure 3; Figures 5, 6, and 7 are detail views of the eccentric
cylinder and connecting parts thereof, with the valve stem of the engine.
The cylinder is constructed without the usual valve face, steam ports, and
steam chest, but has substituted in their place a fixed central cylinder trunk
A, the-axis of the trunk coinciding with the axis of the cylinder. The
trunk A is made with suitable steam ports a, b, which communicate with the
cylinder B, B, and is fitted with a balanced piston valve C. One cylinder
bead D is made hollow and divided into two chambers E and F; E is the
steam chamber, the steam entering through the induction opening G, as shown'
by arrows; F is the exhaust chamber, the steam passing out through the educ-'
tion opening H. One end of the trunk is made with a surrounding case which
is subdivided into two or more compartments or passages c, c, d, d', e, e², f, f',
which: open into the trunk; the passages c, d, e, f, communicate with the
steam chamber E, while passages c, d, e, f, lead into the cylinder B, B.
The trunk A, A, is secured to the cylinder head D by flanges g, g', which close the
steam and vacuum chambers E, F, from the cylinder when the valve C covers
the ports a, b. To allow for the variation of expansion of the cylinder and
trunk and to facilitate the adjustment and removal of the head I, one end of
the trunk A, with the steam port b, is made in a separate piece and secured by
the flange to the cylinder cover I, making a vacuum-tight joint, and is
connected with the other part of the trunk by the tongue and groove i, the
tongue being secured to flange h by a suitable number of webs j, j; the end of

page_text: the main portion of the trunk serves as a margin for the port b, so that
the steam lead will not be affected by the variation which may occur
in the length of the trunk by expansion or the adjustment of the cylinder
head I. The valve C is made a hollow cylinder open at each end,
and having the required cross area through its whole length, which serves
as an exhaust passage from the steam port 6 to the vacuum chamber F.
The annular space J, J, is used as a steam chamber in common with
the steam chamber E, being united by passages c, d, e, f, as above described.
The valve C is fitted with a set of metallic packing rings k, l, for each
steam port, the outside ring of each set being made in two parts as is usual,
but to prevent any liability of variation on the wearing surfaces of the rings
m, n, and o, p, while passing the ports a, b, they are united with a tongue
and groove; grooves s, s, are likewise made on the outer surfaces of the
inner rings, and the inner surfaces of the outer rings with tongues which fit
the
grooves s, s, and secure the rings to the valve. The rings are adjusted by
any of the usual methods in use. The valve is fitted with a stem t, which is
secured to boss u, the stem passing through the stuffing box v, and unites
with the proper connections for receiving the motion required. The piston
K, K, is made annular and fitted as in the usual manner with metallic
packing rings on its circumference; it is likewise fitted with metallic pack-
ing rings working on the trunk A; w, w, are the piston rods, also fitted in
the usual manner.
Operation. The steam being admitted to the annular steam chamber J, J,
as above described, and the port a opened on the steam side, the steam enters
the cylinder behind the piston through the passages c¹, d, e, f, while the
port b is opened on the exhaust side, the steam passing out of the cylinder B, B,
through the valve C into the exhaust chamber F. When steam is taken on
the opposite side of the piston and the port a opened on the exhaust side,
the steam passes out through the passages c, d, e, f, into the exhaust
chamber F, and out of it through the eduction opening H, as indicated by
arrows.
The description of the second part of the present improvements will now be
given, reference being had to the Sheet of Drawings showing the same as herein-
before stated. A in the Drawings represents a spur gear of a convenient
diameter and suitable proportions to do the work required and secured to the
crank shaft B; C represents the cylinder of an adjustable eccentric of a con-
venient size and form to enclose the several parts herein-after specified. On
the circumference of the cylinder C is a spur gear of the same pitch diameter

page_text: as the one keyed to the shaft, and by means of which the cylinder is revolved.
The cylinder C is made with one fixed head a and one movable head b; the
fixed bead a has an oblong rectangular slot c through it; the width and length.
of the slot c depends upon the size of the wrist pin d and the required throw
of the valve, the centre line of the slot c lengthwise to be at a distance from..
the axis of the cylinder equal to that of the lap and lead of the valve. The.
length of the slot e determines the external diameter of that section of the
cylinder C which is used as a journal, and upon which it revolves. The wrist
pin d is made with a rectangular T head e, and rests in a block f, which is
fitted in the slot c in the head a, and is made so as to be capable of moving from
one end of it to the other, the pin & projecting outside the head a a sufficient.
distance to connect with the valve stem or valve stem link. A disc g of
suitable proportions is made to fit the inside of the cylinder C at h¹. Upon
the face of this disc are two segmental lugs i, i, forming a groove between
them for the T head of the wrist pin d to work in, and serving as a means
of communicating motion to it. Two internal gears of the same pattern, the
length and pitch of the teeth depending upon the work to be performed, are
fitted to the largest inside diameter of the cylinder C. One of these gears j is
clutched with the disc g, the other gear k is fixed to the cylinder C. One or
more intermediate twin gears 1, P, m, m³, n, n¹, o, o¹, work into the internal
gears j, k, and are placed equi-distant from each other. Each twin gear is.
pivoted upon its mate, as shown in Figures 3 and 4. The intermediate twin
gears are kept in their relative positions and in contact with the internal
gears j, k, by two pinions p, q, having the same pitch diameter. One of these
pinions p is made on or fixed to the sleeve r; the other pinion 9 is secured. to
the spindle s, which is fitted into and made to turn within the sleeve.r. The
spindle. s projects beyond the sleeve a sufficient distance to receive a lever
gear or a hand wheel t, as may be desired. The intermediate twin gears 7, 1',.
m, m, n, n', o, o, and pinions p, q, are kept in place by the movable head b,
which is secured by bolts or otherwise to the cylinder C. The sleeve r of the
pinion p is fixed to the bracket u, which is secured to the frame or pillow
block D, while the movable head 6 being fitted on the sleeve ? revolves upon
it as a journal. When the arrangement of the engine admits of but, a short
connection between the eccentric and valve stem, as represented in this case,.
to avoid the variation of the lead at the opposite ends of the stroke consequent
upon the obliquity of short connections, the yoke E is used in combination
with the eccentric wrist pin d working in slides and secured to the, valve:
stem r, as shown in Figures 2, 3, and 6, With this combination the lead of

page_text: the valve will be the same on either side at any point of cutting off, whether
the engine is moving either forward or backward. If it is required to make
an eccentric for a valve having less lap in proportion to the throw than the
one represented in this case, or to make an eccentric which can be reduced to
a dead centre, it may be constructed as shown in Figure 7; the wrist pin d at
the part w is made rectangular and fitted to work in the slot c. The head e
of the pin d, which being made as large as the case will admit, bas a
groove on the inside at right angles to the slot in the cylinder C. A
pin y having a T head is pivotted on the disc 9, the T head * working in
groove x.
Operation. With the cylinder C at rest, by turning the pinion 9 by means of
the hand wheelt, or its equivalent, the intermediate gears l, m, n, o, are turned
upon their twins l', m³, n', o¹, which also turns the internal gear ; and the disc g,
the T head of the wrist pin d being clutched with the disc g is turned with it,
forcing the wrist pin d along the slot c. The operation being the same with the
cylinder in motion, the wrist pin d can be moved to any point in the slot c,
varying the cut off or changing the direction of the engine accordingly, while
the wrist pin d by the combination is firmly sustained in any position in which it
is placed..
It may be here remarked, in conclusion, that the improvements con-
stituting the two parts of the above description may be used separate from
each other, or all in one and the same engine, the operation of each part
being entirely.independent of the other.
Having described the nature of this Invention,. and the manner of per-
forming the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is,-
First, arranging the induction and eduction valves of a reciprocating
steam engine so as to work within and through the piston, substantially as
described.
Secondly, the fixed central cylinder trunk A with steam ports and passages
as described.
▲.
. Thirdly, in combination with the fixed central cylinder trunk A the piston
valve C, steam chamber E, vacuum chamber F, and annular piston K, K,
substantially as described.
Fourthly, the intermediate twin gears l, l, m, m³, n, n², o, o², either one or
more of them, in combination with the pinions p, q, internal gears j, k, and
disc g, substantially as described.
Fifthly, the wrist pin d, or its equivalent, and yoke E, in combination

page_text: with the disc g, intermediate twin gears ↳, l, m, m³, n, n¹³, o, o¹, either one
or more of them, internal gears j, k, and pinions p, q, substantially as
described.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Twentieth day of June, in the year of our Lord Our
thousand eight hundred and sixty-six.
Witness,
JAMES DAISH,
58, Chancery Lane,
London.
W. CLARK. (L.S.)