IMPROVEMENTS IN ROTATING SLIDE VALVES, AND FOR IMPROVED SUITABLE MODES OF APPLYING THESE SAID AND OTHER ROTATING VALVES TO CERTAIN KINDS OF ENGINES
Year: 1868

page_text: LETTERS PATENT to Charles William Dixon, of Wickham Market,
in the County of Suffolk, Civil Engineer, for the Invention of
"IMPROVEMENTS IN ROTATING SLIDE VALVES, AND FOR IMPROVED SUITABLE
MODES OF APPLYING THESE SAID AND OTHER ROTATING VALVES TO CERTAIN
KINDS OF ENGINES."
Sealed the 24th July 1868, and dated the 25th January 1868,
PROVISIONAL SPECIFICATION left by the said Charles William Dixon
at the Office of the Commissioners of Patents, with his Petition, on
the 25th January 1868,
I, CHARLES WILLIAM DIXON, of Wickham Market, in the County
of Suffolk, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ROTATING SLIDE VALVES, AND FOR
IMPROVED SUITABLE MODES OF APPLYING THESE SAID AND OTHER ROTATING VALVES
TO CERTAIN KINDS OF ENGINES," to be as follows:-
My Invention consists of several improved forms or modifications
of slide valves constructed on the rotating principle for the purpose
of regulating the admission of steam, air, water, or other gases or
fluids, as the case may be, into and the discharge of the same from
the cylinders of engines actuated by any of these said or other gases or

page_text: fluids; and also of certain improved suitable modes of applying these
my aforesaid and other rotating valves to certain kinds of engines, which
I shall hereafter denominate my improved forms of rotating valve gear.
My improved rotating slide valves may in all cases be driven by
any suitable mechanical appliances, which I leave entirely optional,
and so let it be clearly understood that. I do not claim my improved
rotating slide valves in combination only with my improved forms of
rotating valve gear, nor my improved forms of rotating valve gear
likewise in combination only with my improved rotating slide valves,
but with my aforesaid and other rotating valves for certain kinds of
engines.
One object of this Invention is the production of slide valves,
constructed on the rotating principle, which may be so formed and
adjusted as to permit the use of that economical device commonly
termed expansion, and also as to prevent a useless expenditure or waste
of power in driving them.
Another object of this Invention is the prevention of vibration and
oscillation in engines by means of my improvements, which increase
the number of those parts that revolve and diminish the number of
those that reciprocate.
My improvements are applicable to engines of all kinds and for all
purposes, but especially to those designed for revolving at high velocities.
For the sake of simplicity I shall hereafter describe my improvements
as applied to engines driven by the pressure of steam, as the action of
other gases or fluids is of a somewhat similar nature.
My improved rotating slide valves are each and all made in two
parts, namely, the moveable and the fixed, the former of which I shall
hereafter denominate the valves, and the latter the valve seats. These
said valves and valve seats are of different forms or shapes, hereafter
to be mentioned, having frustro-conical, hemispherical, or spherical
segmental faces. The ports or openings on both these said valves and
valve seats in each and all of my several forms of rotating slide valves
are, with certain exceptions to be hereafter mentioned, three in number,
two of which are of that kind commonly termed steam ports, and the
third are the exhaust ports. The exhaust ports on both these said
valves and valve seats are used only for the purpose of discharge, but
the steam ports on the aforesaid valve seats are used alternately for
both admission and discharge. One of the two steam ports on the

page_text: aforesaid valves is connected with the exhaust port on the same by a
covered passage, and is used only for the purpose of discharge, but the
other steam port on the same has, with one exception to be hereafter
mentioned, a free passage or opening to that part of the engine
commonly termed the valve chest, and is used only for the purpose of
admission. The exceptions above mentioned to my improved rotating
slide valves being three-ported are in the slide valves for single-acting
engines, and likewise also in those for double-acting engines when
separate valves and valve seats are employed for each end of the
cylinder, and in both these cases one of the two steam ports on the said
valve seats is wanting. My improved rotating valves are in all cases
placed in that part of the engine commonly termed the valve chest, of
which the valve seat forms a side or boundary, and which at option may
either be cast in one piece with the cylinder or be otherwise attached to
it. My improved rotating valves are kept in their places partly by the
pressure of the steam in their valve chests which forces them against
their valve seats with an amount of adhesion equal to the pressure of
the aforesaid steam in pounds on the square inch in the above-mentioned
valve chests multiplied by the area of the exhaust ports in inches. In
order if deemed desirable to prevent a useless expenditure or waste of
power in driving these said valves this amount of adlision to their seats
may be reduced to any required degree by the introduction on the
bases or backs of the said valves and together forming a part of them
of a cylindrical projection which passes through a stuffing box to the
atmosphere. The diameter of this said cylindrical projection will
regulate this adhesion, which will be reduced in degree the nearer it
approaches to the diameter of the said exhaust ports, which in each
and all of these several forms of rotating slide valves are made of a
circular form, but the said cylindrical projection must not be greater
in diameter than the said exhaust ports. When of the same diameter
they will theoretically balance each other, but this for evident reasons
is not advisable, as a certain amount of adhesion is requisite in practice.
The centre of the said cylindrical projection must lie in the centre line of
the valve's rotation. Here let it be noted that I may sometimes prefer
to use my aforesaid cylindrical projection as an admission or steam
pipe. In this case the said cylindrical projection after being produced
as above stated through a stuffing box to the atmosphere will enter
the steam pipe of the engine through another stuffing box, or be
otherwise attached to it, and here occurs that exception above mentioned

page_text: to one of the steam ports on the valve being connected with the valve
chest by a free passage or opening, it being now connected with the
said cylindrical projection by a covered passage or connection, and
here also let it be noted that I may sometimes employ moveable valve
seats in my improved forms of rotating slide valves for the purpose of
reversing the motion of the engine to which they are applied.
Having now described what is common to all my improved modi-
fications of rotating slide valves, I will next proceed to describe what
is peculiar to each of them.
One modification of my improved rotating valves is made frustro-
conical, or, in other words, of the form or shape of a frustrum of a cone
upon the convex surface of which its two steam ports are placed. The
valve seat for this form of valve is also made frustro-conical and with the
same amount of slope or taper as the said valve upon the concave surface
of which its two steam ports are placed. The exhaust ports which are
of a circular form are placed in the centre line of revolution on the
top surfaces of this said frustro-conical valve and valve seat, and that
on the former covers that on the latter. The two steam ports on both
this said frustro-conical valve and valve seat are bounded on their tops
and bottoms by arcs of circles surrounding the same, and have their
sides, parts of radial lines from the imaginary apex or vertex of the
said frustro-conical valve and valve seat, and their size and position is
regulated by the dimensions of the cylinder and the amount of cut off
of steam, if expansion is used.
Other modifications of my improved rotating slide valves are those
made with hemispherical faces, or, in other words, with faces of the
form or shape of a hemisphere, and those made with spherical segmental
faces, or, in other words, with faces of the form or shape of a segment
of a sphere. In these said forms of rotating slide valves the exhaust
ports which are of a circular form are placed in the centre of revolution,
being brought to the surfaces or faces of these said hemispherical and
spherical segmental valves and valve seats, and those on the former
cover those on the latter. These said valves in both cases present
convex and these said valve seats concave surfaces. The two steam
ports on these said valve seats are placed on either side of the exhaust
ports on their concave surfaces, a rib of metal intervening, and have
their outer and inner sides arcs of concentric circles from the same

page_text: centre as the exhaust ports, and are bounded on their other sides by
parts of radial lines from the same said centre, and their size is regulated
by the dimensions of the cylinder and the amount of cut off of steam
if expansion is used. The two steam ports on these said valves are
placed on their convex surfaces, and are bounded on their outer and
inner sides by arcs of concentric circles of the same diameter as those
which bound the outer and inner sides of the steam ports on the
aforesaid valve seats, and described from the same centre as the
exhaust ports, and are bounded on their other sides by parts of
radial lines from the same said centre, and their size and position
also is regulated by the dimensions of the cylinder and the amount
of cut off of steam if expansion is used. These my improved
frustro-conical, hemispherical, and spherical segmental rotating slide
valves may be driven either by spindles attached to their bases or backs,
or at option by any other suitable mechanical appliances, and may if
deemed desirable be formed with cylindrical projections, as above
stated, for the purpose of regulating their adhesion, and of sometimes
forming an admission or steam pipe, and may also be fitted with
moveable valve seats for the purpose of reversing the motion of the
engine to which they are applied.
The action of my improved rotating slide valves is as follows:-The
valve performs one revolution for every double stroke of the piston or
single revolution of the crank, and the steam is first admitted from the
valve chest, or from the cylindrical projection if used as a steam pipe,
through one steam port on the valve, then through another on the
valve seat to one side of the piston, and the steam previously admitted
to the other side of the same is discharged through the other steam
port on the said valve seat, being the same by which it entered, and it
then passes through the steam port, covered passage, and exhaust port
all on the aforesaid valve, into the exhaust port on the aforesaid valve
seat, and then after passing through the exhaust pipe connected
therewith is discharged into the atmosphere, condenser, or otherwise as
the case may be. These admissions and discharges above mentioned
take place during either the whole or a part of the valve's half revolution.
This action is reversed during its next half revolution.
One modification of my improved forms of rotating valve gear
consists of two pitch or cog wheels, one of which is attached to or cast
in one piece with the valve, which must of necessity be constructed on

page_text: a rotating principle, and the other is placed on the crank shaft, which
in this case enters the valve chest and drives the valve direct by means
of the said wheel attached to it, being placed in gear with the wheel
on the said valve. This form of rotating valve gear is suitable for
small pumping engines having return connecting rods and crank
shafts.
Another modification of my improved forms of rotating valve gear
consists of two wheels with pins, catches, cogs, or teeth, either forged,
cast, inserted, or formed, as the case may be, on their circumferences,
one of which is placed on the crank shaft or other revolving part of the
engine, and the other either on the valve or valve spindle attached to
it, or on some other mechanical appliance connected therewith, and the
former drives the latter by means of either an endless pitch chain or
friction band of any material or by an endless steel pitch band. The
valve in this case also must be of necessity constructed on a rotating
principle. This said form of rotating valve gear is applicable to rotative
engines, or, in other words, to those engines provided with a crank by
means of which a rotative motion is produced.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles William Dixon in the Great Scal Patent
Office on the 25th July 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM DIXON, of Wickham Market, in the County of Suffolk, Civil
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of January, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirtieth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles William Dixon, Her special
licence, that I, the said Charles William Dixon, my executors,
administrators, and assigns, or such others as I, the said Charles
William Dixon, 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

page_text: 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 ROTATING SLIDE VALVES,
AND FOR IMPROVED SUITABLE MODES OF APPLYING THESE SAID AND OTHER ROTATING
VALVES TO CERTAIN KINDS OF ENGINES," upon the condition (amongst
others) that I, the said Charles William Dixon, my executors or
administrators, 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 Charles William Dixon, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and the following statement :-
My Invention consists of certain improved modifications of rotating
slide valves for the purpose of regulating the admission of steam,
air, water, or other gases or fluids, as the case may be, into and the
discharge of the same from the cylinders of engines actuated by any
of these said or other gases or fluids; and also of certain improved
suitable modes of applying these my aforesaid and other rotating
valves to certain kinds of engines, which I shall hereafter denominate
my improved forms of rotating valve gear. My improved rotating
slide valves may in all cases be driven by any suitable mechanical
appliances, which I leave entirely optional, and so let it be clearly
understood that I do not claim my improved rotating slide valves in
combination only with my improved forms of rotating valve gear;
nor my improved forms of rotating valve gear likewise in combination
only with my improved rotating slide valves, but with my aforesaid
and other rotating valves for certain kinds of engines.
One object of this Invention is the production of slide valves con-
structed on a rotating principle, which may be so formed and adjusted
as to permit the use of that economical device commonly termed
expansion, and also as to prevent a useless expenditure or waste of
power in driving them.
Other objects of this Invention are the prevention of vibration and
oscillation in engines by means of my improvements, which increase

page_text: the number of those parts that revolve and diminish the number of
those that reciprocate; and also the diminution of the working parts
of the same, as a single valve gear constructed on my improved
principle will drive valves for two or more cylinders, each of the said
valves being set at its own proper angle on the valve spindle.
My improvements are applicable to engines of all kinds and for all
purposes, but especially to those designed for revolving at high
velocities. For the sake of simplicity I shall hereafter describe my
improvements as applied to engines driven only by the pressure of
steam, as the action of other gases and fluids is of a somewhat
similar nature.
My improved rotating slide valves consist each and all of two parts,
namely, the moveable and the fixed, the former of which I shall
hereafter denominate the valves, and the latter the valve seats.
These said valves and valve seats have either frustro-conical hemi-
spherical, or spherical segmental faces, hereafter to be mentioned, and
are of the following construction:-The ports or openings on both
these said valves and valve seats in each and all of my several forms
of rotating slide valves are, with certain exceptions hereafter to be
mentioned, threc in number, two of which are of that kind commonly
termed steam ports, and the third are the exhaust ports. The exhaust
ports on both these said valves and valve scats are used only for the
purpose of discharge, but the steam ports on the aforesaid valve seats
are used alternately for both admission and discharge. One of the
two steam ports on the aforesaid valves is connected with the exhaust
port on the same by a covered passage, and is used only for the
purpose of discharge; but the other steam port on the same has,
with one exception hereafter to be mentioned, a free passage or opening
to that part of the engine commonly termed the valve chest, and is
used only for the purpose of admission. The exceptions above-
mentioned to my improved rotating slide valves being three-ported
are in the slide valves for single-acting engines, and likewise also in
those for double-acting engines when separate valves and valve seats
are employed for each end of the cylinder, and in both these cases
one of the two steam ports on the said valve seats is wanting. My
improved rotating valves are in all cases placed in that part of the
engine commonly termed the valve chest, of which the valve seat
forms a side or boundary and which at option may either be formed

page_text: in one piece with the cylinder or be otherwise attached to it. My
improved rotating valves are kept in their places partly by the pressure
of the steam in their valve chests, which presses them against their
valve seats with a force or adhesion equal to that of the pressure of the
aforesaid steam in pounds on the square inch in the above-mentioned
valve chests multiplied by the area of the exhaust ports in inches. In
order, if deemed desirable, to prevent a useless expenditure or waste of
power in driving these said valves this amount of adhesion to their seats
may be reduced to any required degree by the introduction on the basis
or backs of the said valves, and together forming a part of them, of a cylin-
drical projection which passes through a stuffing box to the atmosphere.
The diameter of this said cylindrical projection will regulate this adhesion,
which will be reduced in degree the nearer it approaches to the diameter
of the said exhaust ports, which in each and all of these several forms
of rotating slide valves are made of a circular form, but the said
cylindrical projection must not be greater in diameter than the said
exhaust ports; when of the same diameter they will theoretically
balance each other, but this for evident reasons is not advisable, as a
certain amount of adhesion is requisite in practice. The centre of
this said cylindrical projection must lie in the centre line of the
valve's rotation. Here let it be noted that I may sometimes prefer
to use my aforesaid cylindrical projection as an admission or steam
pipe. In this case the said cylindrical projection after being produced
as above stated through a stuffing box to the atmosphere will enter
the steam pipe of the engine through another stuffing box, or be
otherwise attached to it; and here occurs that exception above
mentioned to one of the steam ports on the valve being connected
with the valve chest by a free passage or opening, it being now also
connected with the said cylindrical projection by a covered passage or
some other connection; and here also let it be noted that I may some-
times employ moveable valve seats in my improved forms of rotating
slide valves for the purpose of reversing the motion of the engines to
which they are applied.
Having now described what is common to all of my improved
• modifications of rotating slide valves, I will next proceed to describe
what is peculiar to each of them.
One modification of my improved rotating valves is made frustro-
conical, or, in other words, of the form or shape of a frustrum of a

page_text: cone, upon the convex surface of which its two steam ports are placed.
The valve scat for this form of valve is also made frustro-conical and
with the same amount of slope or taper as the said valve, upon the
concave surface of which its two steam ports are placed. The exhaust
ports, which are of a circular form, are placed in the centre line of
rotation on the top surfaces of this said frustro-conical valve and valve
seat, and that on the former covers that on the latter. The two steam
ports on both these said frustro-conical valve and valve seat are
bounded on their upper and lower sides by arcs of circles surrounding
the same, and have their other two sides parts of radial lines from the
imaginary apex or vertex of the said frustro-conical valve and valve
seats, and their size and position is regulated solely by the dimensions
of the cylinder and the amount of cut off of steam if expansion is
used, or, in other words, by the usual rules now in practice for designing
other valves for the same purpose.
Figs. 13 and 14, Sheet II., illustrate respectively a side view and a
plan of a frustro-conical valve on my improved principle, in which
Qrepresents the exhaust port which is made of a circular form, and
placed in the centre of rotation on the top surface of the valve.
P, P, represent the two steam ports which have their upper and lower
sides H and I arcs of circles K and M surrounding the valve, and
their other sides F and G parts of radial lines from the imaginary
apex or vertex C of the. same said frustro-conical valve.
Figs. 1, 2, and 3, Sheet I., also represent a frustro-conical valve and
valve seat on my improved principle, but formed with a different
amount of slope or taper to that illustrated in Figs. 13 and 14,
Sheet II.
Fig. 1 is a section in plan through the centre of the valve; Fig. 2,
a cross section of the same, and Fig. 3 a section through the valve
chest o, showing the valve seat b from which the valve a is removed.
In Figs. 1, 2, and 3, a is the valve; b, the valve seat; g, the cylindrical
projection; d, the steam ports on the valve; d, d, the same on the valve
seat; c, the exhaust port on the valves; c, c, the same on the valve seat;
f, the covered passage connecting one of the steam ports d on the valve
with the exhaust port c on the same. The other steam port d on the
valve a has a free passage or opening e to the base or back of the
said valve for the admission of steam from the valve chest o. The
cylindrical projection g is produced through the stuffing box x to the

page_text: atmosphere for the purpose above stated, and is shown as formed with
a socket to receive a valve spindle. Here let it be noted that this
may if deemed desirable be driven direct from the cylindrical projection
without the intervention of a valve spindle, or the said valve may if
preferred be without the cylindrical projection and be formed with a
socket to receive a valve spindle which will enter the valve chest o
through the stuffing box x, or be produced the other way through the
exhaust port c, c, on the valve seat.
Other modifications of my improved rotating slide valves are those
made with hemispherical, or, in other words, with faces of the form or
shape of a hemisphere, and those made with spherical segmental
faces, or, in other words, with faces of the form or shape of a segment
of a sphere. In these said forms of rotating slide valves, the exhaust
ports which are of a circular form, are placed in the centre of
revolution on the surfaces or faces of these said hemispherical and
spherical segmental valves and valve seats, and those on the former
cover those on the latter. These said valves in both cases present
convex and these said valve seats concave surfaces. The two steam
ports on these said valve seats are placed on either side of the exhaust
ports on their concave surfaces, a rib of metal intervening, and have
their outer and inner sides arcs of concentric circles from the same
centre as the exhaust ports, and are bounded on their other sides by
parts of radial lines from the same said centre, and their size is
regulated by the dimensions of the cylinder and the amount of cut
off of steam if expansion is used. The two steam ports on these said
valves are placed on their convex surfaces, and are bounded on their
outer and inner sides by arcs of concentric circles of the same
diameter as those which bound the outer and inner sides of the steam
ports on the aforesaid valve seats and described from the same
centre as the exhaust ports, and are bounded on their other sides by
parts of radial lines from the same said centre and their size and
position is regulated by the dimensions of the cylinder and
the amount of cut off of steam if expansion is used. These said
forms of valves and valve seats are illustrated by Figs. 4, 5, 6, and
37 on Sheet I., in which Figs. 4 and 5 represent respectively a section
through the centre of a hemispherical valve and valve seat; and an
elevation of the same said hemispherical valve seat with the valve
removed to show its concave surface, in the centre of which is
placed the exhaust port c, c, and on either side of it the steam ports

page_text: d, d, d, d. Figs. 6 and 7 are a like section and elevation of a spherical
segmental valve and valve seat.
In Figs. 4, 5, 6, and 7, a is the valve; b, the valve seat; c, the
exhaust port on the valve; c, c, the same on the valve seat; d, the
steam ports on the valve; d, d, the same on the valve seat; f, the
covered passage on the valve connecting the steam port d with the
exhaust port c on the same; e is the free passage or opening to
the other steam port d on the valve a for the admission of steam
from the valve chest o; g is the cylindrical projection; i, a valve
spindle; h, a socket to receive the said valve spindle i; x, the stuffing
box and y the cylinder.
Figs. 15 and 16 on Sheet II. are also a side view and a plan of a spherical
segmental valve on my improved principle, in which K is the exhaust
port placed in the centre of revolution on its convex surface; F, F,
are the two steam ports which are bounded on either side by parts
of radial lines from the centre C of the exhaust port and also of
revolution. These said steam ports have their inner and outer sides
O and Parcs of circles from the same said centre C. A projection Z
is shown surrounding the exhaust port K, which said projection enters
the exhaust port on the valve seat, and which I sometimes employ for
the purpose of helping to keep the valve in its place, though I leave
the use of it optional. The same said projection is also shown in Figs. 4
and 6 on Sheet I.
Figs. 10 and 11, Sheet II., illustrate respectively a sectional plan
and cross section of a frustro-conical valve with a moveable valve
seat I for the purpose of reversing the motion of the engine to which
it is applied. This valve is suitable either for a single-acting engine
or for a double-acting engine if separate valves and valve seats are
employed for each end of the cylinder and so as above stated, one of
the two steam ports on the said valve seat is wanting. The cylindrical
projection G is here shown as used for an admission or steam pipe,
and is therefore connected with one of the steam ports D on the
valve Z. I is the moveable valve seat which is produced through a
stuffing box O previous to entering the exhaust pipe H, H, H, through
the stuffing box B. L is a lever or handle attached to the moveable
valve seat I, which being turned half round will place the valve in
backward gear, and so reverse the motion of the engine to which it is
applied. H is an exterior case or fixed valve seat, and K a space for
the admission of steam to the cylinder; this said space K is of the form

page_text: or shape of an annular arc so as to be always connected with the
steam port C on the moveable valve seat I in all its various positions.
The cylindrical projection G enters the steam pipe U through the
stuffing box V. T is a pitch wheel hereafter to be mentioned for driving
the valve Z from its cylindrical projection G; and S, S, is an endless
steel pitch band. These my improved frustro-conical, hemispherical,
and spherical segmental rotating slide valves may be driven either by
spindles attached to their bases or backs, or at option by any other
suitable mechanical appliances, and may if deemed desirable be formed
with cylindrical projections; as above stated, for the purpose of regulating
their adhesion and of sometimes forming an admission or steam pipe,
and may also be fitted with moveable valve seats for the purpose of
reversing the motion of the engine to which they are applied.
The action of my improved rotating slide valves is as follows:-The
valve performs one revolution for every double stroke of the piston or
single revolution of the crank, and the steam is first admitted from
the valve chest, or from the cylindrical projection if used as a steam
pipe, through one steam port on the valve, then through another on
the valve seat to one side of the piston, and the steam previously
admitted on the other side of the same is discharged through the
other steam port on the said valve seat, being the same by which it
entered, and it then passes through the steam port, covered passage,
and exhaust port, all on the aforesaid valve, into the exhaust port
on the aforesaid valve seat, and then after passing through the exhaust
pipe connected therewith is discharged into the atmosphere, condenser,
or otherwise as the case may be. These admissions and discharges
above mentioned take place during either the whole or a part of
the valve's half revolution, and this action is reversed during the
next half revolution.
One modification of my improved forms of rotating valve gear consists
of two pitch or cog wheels, one of which is attached to or cast in
onc piece with the valve, which must of necessity be constructed on
a rotating principle, and the other is placed on the crank shaft, which
in this case enters the valve chest and drives the valve direct by
means of the said wheel attached to it, being placed in gear with the
wheel on the said valve. This form of rotating valve gear is suitable
for small pumping engines having return connecting rods and crank
shafts and I illustrate it in Fig: 12, Sheet II., as thus applied, in

page_text: which K is the crank pin to receive a return connecting rod; Z is
the fly wheel placed on the return crank shaft L which enters the valve
chest V through the stuffing box X and drives the rotating valve F
direct by means of the wheel B attached to it, being placed in gear
with the wheel E on the valve F.
Another modification of my improved forms of rotating valve
gear consists of two wheels with pins, catches, cogs, or teeth either
forged, cast, inserted, or formed as the case may be on their cir-
cumferences, one of which is placed on the crank shaft or other
revolving part of the engine, and the other either on the valve or
valve spindle attached to it or on some other mechanical appliances
connected therewith, and the former drives the latter by means of
either an endless pitch chain of any material, friction band, or endless
steel pitch band. The valve in this case must also be of necessity
constructed on a rotating principle. A gear on this principle is
illustrated in Figs. 8 and 9, Sheet I., in which m, m, are two pitch
wheels with teeth o, o, o, formed on their circumferences, one of
which is placed on the crank shaft K, and the other on the valve
spindle, and the former drives the latter by means of the endless
steel pitch band S, S. Figs. 8 is an elevation and Fig. 9 a plan in
which P, P, represent the pitch holes in the steel band S, S, for
the reception of the teeth o, o. This said form of gear is applicable
to rotative engines, or, in other words, to those engines provided with
a crank by means of which a rotative motion is produced.
Having now described my said Invention for "Improvements in
Rotating Slide Valves, and for Improved suitable Modes of Applying
these said and other Rotating Valves to certain Kinds of Engines," and
having explained the manner of carrying the same into effect, I
wish it to be understood that what I claim is,-
Firstly. The improved rotating slide valves with either frustro-
conical, hemispherical, or spherical segmental faces, and sometimes
formed with cylindrical projections for the purpose of regulating their
adhesion or of forming an admission or steam pipe, and which may
also be fitted with moveable valve seats for the purpose of forming
a reversing gear.
Secondly. The improved forms of rotating valve gear suitable in
certain cases for driving the aforesaid and other rotating valves, sub-
stantially as herein-before described.

page_text: I have not needlessly amplified this my Specification, as any com-
petent workman will now be able to produce any part of it from my
description, and it should here be noted that the Diagrams only
illustrate certain modifications of my Invention ascertained from the
above statement.
I therefore claim as secured to me by Her Majesty's Letters Patent
the right to construct rotating valves and rotating valve gear, as
herein-before described and illustrated and substantially so constructed.
In witness whereof, I, the said Charles William Dixon, have
hereunto set my hand and seal, this Twenty-ninth day of June,
in the year of our Lord One thousand eight hundred and
sixty-eight.
Witness,
CHARLES WILLIAM DIXON. (L.S.)
JOHN DIXON,
Incumbent of Letheringham,
Suffolk.