IMPROVEMENTS IN STEAM OR OTHER MOTIVE ENGINES. AND IN SAFETY VALVES AND ARRANGEMENTS FOR PREVENTING DAMAGE OR ACCIDENTS IN STEAM BOILERS
Year: 1868

page_text: LETTERS PATENT to Walter Charles Church, of Derby, in the County
of Derby, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
OR OTHER MOTIVE ENGINES. AND IN SAFETY VALVES AND ARRANGEMENTS
FOR PREVENTING DAMAGE OR ACCIDENTS IN STEAM BOILERS."
Scaled the 1st April 1869, and dated the 16th October 1868.
PROVISIONAL SPECIFICATION left by the said Walter Charles Church
at the Office of the Commissioners of Patents, with his Petition,
on the 16th October 1868.
I, WALTER CHARLES CHURCH, of Derby, in the County of Derby,
Engineer, do hereby declare the nature of the said Invention for "IM.
PROVEMENTS IN STEAM OR OTHER MOTIVE ENGINES, AND IN SAFETY VALVES AND
ARRANGEMENTS FOR PREVENTING DAMAGE OR ACCIDENTS IN STEAM BOILERS,"
to be as follows:-
My improvements in steam and other motive engines are made upon
those for which Letters Patent were granted to me, dated the Sixth day
[Price Sd.]

page_text: of July, in the year of our Lord One thousand eight hundred and sixty-
seven, and numbered 1974.
Firstly. My present improvements relate to the arrangements for
removing the pressure from the backs of slide valves described under
the first head of the Specification of my said Patent, and consist in an
improved construction, combination, and arrangement of the parts,
namely, in forming a circular groove in that surface of the cap or ring
which works against the plate, so as to intercept or cut off any steam that
may leak past the outer surface of the face of the ring or cap, such
leakage being taken from the said circular groove through one or more
small holes to the inside of the cap or ring, and from thence by small
holes at the inner edge of the cap or ring to the cavity between the cap
or ring and the plate. The said cap or ring is made only with one
cylindrical flange or projection at its outer edge, instead of having two
(one on each edge), and the inner surface of the projection of the ring
is of cone form. Instead of two packing rings, one within the other,
one ring only is used, the joint being covered or broken by a segment of
ring of L-section. This packing ring is not made of annular form, but
its inner circumference is excentric to its outer circumference, so that it
will expand outwards with uniform elastic force. The outer surface of
the packing ring is also made of cone form, and when it expands by
its own elasticity, and by the pressure of the steam acting upon it, the
ring or cap is forced outwards against the plate, as the conc exterior of
the packing ring acts upon the cone interior of the ring or cap. The
back of the valve has a projection which has a screw thread in it, and
the junk ring has also a thread to screw upon the projection, and an
inner ledge on the junk ring is curved to a radius equal to that of the
inner edge of the ring or cap, the two edges fitting one to the other, so
that the ring or cap will have perfect liberty to oscillate to accomodate
itself to wear or want of parallelism to the plate. Two or more caps
or rings, arranged as above described, may be combined together on
the same valve, and such caps or rings on one valve may be arranged
to work against a plate secured to the back of an adjoining valve.
In applying the improvements to existing engines the middle plate
between two sets of valves may be made with projections on one side
and at one end, and set screws may be tapped into the projections, by
which the plate can be adjusted and secured centrally, being held by a
bracket secured to the steam chest lid at the other end. Holes may be

page_text: formed in the plate between the cavities within the rings or caps, and
one or more pipes may be used to take away the leakage. The end of
the outlet pipe or pipes may be brought to a level above the valves,
so as to retain the condensed steam which may escape past the ring
or cap.
Secondly. My improvements relate to pistons, and are made upon
those described under the second part of the Specification of my said
Patent, and consist in an improved combination by dispensing with one
inner ring, and in using segmental pieces straight on one side to cover
the joints of the packing ring acting against the cylinder; also making
the packing rings against the cylinder in two parts, and in forcing these
two rings apart against the junk ring and piston head by an elastic
collapsing ring, straight on one side and bevelled on the other.
Thirdly. My improvements relate to safety valves, and consist in
making the outlet for the escaping steam of annular form, and in
covering this by an annular or ring valve held down by a weight or
weights, weighted lever, or springs. When the steam escapes by the
lifting of this valve it passes both into the interior and exterior of the
ring valve, and will thus have more free outlet than in the ordinary
valve. To make the valve still more safe and prevent the pressure from
increasing beyond the point fixed upon, my Invention consists in
enclosing the inner part of the valve so that the escaping steam will
accumulate and force the valve open to the utmost, the extent to which
this force is to act being regulated by forming an outlet from the valve,
or an outlet in communication with the cavity of the valve, and covering
such outlet by another valve loaded by a spring or weight to adjust the
lifting action of the valve.
Another improvement under this part of my Invention relates to
apparatus for injecting steam or water or both upon the fire of the boiler
furnace when the water gets too low, so as to put out the fire and
prevent damage or explosion; and this part of my improvements consists
in an improved combination and arrangement of parts, namely, a float
in the boiler acting on a lever connected with a valve, which is opened
by the float when the water is too low; this allows the steam to act upon
a ram piston which moves a slide valve that allows the water or steam to
escape, which is conveyed by a suitable pipe to the furnace; a sealed
cock may be used in the pipe to close it when the fireman's attention has
been drawn to it,

page_text: My improvements under this head also consist in combining the
improvements last described with the improvements in safety valves
first described under this head, by placing the valve actuated by the
float in the centre of the safety valve seating, the piston branching
horizontally. When so combined the valve actuated by the float also
admits steam to the interior cavity of the safety valve, and at the same
time allows steam to escape therefrom. The float and valve may be used
alone to admit steam to lift the safety valve when the water is too low,
and thus relieve the boiler. Arrangements are used so that the float
valve may be opened at any time from the exterior of the boiler, but
such arrangements do not prevent the float from acting to open the
valve when the water is too low.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Walter Charles Church in the Great Seal Patent
Office on the 16th April 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
CHARLES CHURCH, of Derby, in the County of Derby, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of October, in the year of
our Loid One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself. Her heirs and successors,
give and grant unto me, the said Walter Charles Church, Her special
licence that I, the said Walter Charles Church, my executors, adminis-
trators, and assigns, or such others as I, the said Walter Charles
Church, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 Inven-
tion for "IMPROVEMENTS IN STEAM OR OTHER MOTIVE ENGINES, AND IN SAFETY
VALVES AND ARRANGEMENTS FOR PREVENTING DAMAGE OR ACCIDENTS IN STEAM
BOILERS. upon the condition (amongst others) that I, the said Walter

page_text: Charles Church, 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 Walter Charles Church, 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
by the following statement, reference being had to the Drawings here-
unto annexed, and to the letters and figures marked thereon (that
is to say)-
My Invention of "Improvements in Steam or other Motive Engines,
and in Safety Valves and Arrangements for preventing Damage or
Accidents in Steam Boilers," relates to improvements on an Inven-
tion for which Letters Patent were granted to me, bearing date the
Sixth day of July, One thousand eight hundred and sixty-seven, and
No. 1974.
My present improvements relate, in the first place, to arrangements
for removing the pressure of steam from the backs of slide valves
described under the first head of the Specification of my said Patent,
and consist in the improved construction, combination, and arrange-
ment of the parts herein-after described, namely, in forming a circular
groove in that face of the cap or ring which works against the division
plate, so as to intercept or cut off any steam that may leak past the
outer portion of the face of the cap or ring, such leakage being taken
from the said circular groove through one or more small holes to the
inside of the cap or ring, and from thence by small holes at the inner
edge of the cap or ring to the space between the cap or ring and
the division plate. The said cap or ring is made with only one
cylindrical flange or projection at its outer edge instead of two (one
on each edge) as in the Invention above referred to, and the inner
surface of the said flange or projection is conical in form. Instead
of two packing rings, one within the other, as in my former Inven-
tion, only one ring is used, the joint being covered or "broken" by
a segment of L-section. This packing ring is not made of a true
annular form, but its inner circumference is excentric to its outer

page_text: circumference, so as to render it capable of expanding outwards with
uniform clastic force. The outer surface of the packing ring is also
made conical, and when this ring expands by its own clasticity, and
by the pressure of the steam acting upon it, the cap or ring is forced
against the division plate as the conical outer surface of the packing
ring acts upon the conical inner surface of the cap or ring. On the
back of the valve is a projecting part which has a
screw thread
formed on it, and the junk ring has a corresponding female screw
admitting of its being screwed thereon. An inner ledge on the
junk ring is curved to. a radius equal to that of the inner edge of
the cap or ring, the two edges fitting one to the other so that the
cap or ring will be free to oscillate so as to accommodate itself
to wear or want of parallelism to the division plate. Two or more
caps or rings, arranged as above described, may be combined
together on the same valve, and such caps or rings on one valve
may be arranged to work against a plate secured to the back of
an adjoining valve. In this case the cap or ring is only required
to be applied to the back of one of the valves, and passages for the
outlet of leakage from the cap or ring to the atmosphere are formed
in the centre bearing of both valves and in the centre bar of the
exhaust ports. In adapting and applying the improvements to existing
engines, the middle plate between two sets of valves may be made with
projections on one side and at one end, and set screws may be tapped
into the projections by which the plate can be adjusted and secured
centrally, being held by a bracket secured to the steam chest lid at
the other end. Holes may be formed in the plate between the cavities
within the caps or rings, and one or more pipes may be used to take
away the leakage. The end of the outlet pipe or pipes may be brought
to a level above the valves so as to retain the condensed steam which
may escape past the cap or ring.
My Invention relates, in the second place, to improvements in pistons
described in the Specification of my former Patent above referred to,
and consists in dispensing with one inner ring therein described and in
using segmental pieces straight on one side to cover the joints of
the packing rings acting against the cylinder; also in inserting two
packing rings to work against the inside of the cylinder, and in
forcing these two rings apart against the junk ring and piston head
by means of an elastic collapsing ring straight on one side and bevilled
on the other,

page_text: .
And my Invention relates, in the third place, to improvements in
safety valves and apparatus for preventing damage and accidents in
steam boilers. With reference to safety valves, my Invention consists
in making the outlet for the escaping steam of annular form, and in
covering this with an annular or ring valve held down as required,
either by a weight or weights, or by a weighted lever or by springs.
When the steam escapes by the lifting of this valve it passes into the
interior of the same, and will thus have more free outlet than in
safety valves of the ordinary construction. For still greater security,
and in order to prevent the pressure from increasing from beyond the
point fixed upon, the inner part of the valve is enclosed so that the
escaping steam will accumulate and force the valve open to the full
extent, the degree to which this force is intended to act being regulated
by forming an outlet from the valve or an outlet in communication
with the cavity of the valve, and covering such outlet by another
valve loaded by a spring or weight to adjust the lifting action of
the valve.
My Invention with reference to apparatus for preventing damage
or accidents in steam boilers relates to apparatus for injecting steam, or
water, or both, upon the fire of the boiler furnace when the water gets
too low, so as to put out the fire and prevent damage or explosion.
And my Invention herein consists in the use of a float in the boiler
acting on a lever connected with a valve which is opened by the action
of the float when the water is too low, which allows the steam to act
on a ram piston and open a slide valve, thereby allowing the water or
steam to escape, which is conveyed by a suitable pipe to the furnace.
A throttle valve or cock as herein-after described may be used in the
pipe in order to close it when required, and thereby prevent the steam
or water from putting out the fire.
My Invention also consists in combining the apparatus just referred
to with the improvements in safety valves above referred to, by placing
the valve actuated by the float in the centre of the safety valve seating,
the piston branching horizontally. When so combined the valve actuated
by the float also admits steam to the internal cavity of the safety valve,
and at the same time allows steam to escape therefrom. The float and
valve may be used alone to admit steam to lift the safety valve when
the water is too low and thus relieve the boiler. Arrangements are used
by which the float valve may be opened at any time from the exterior

page_text: of the boiler, but such arrangements do not prevent the float from
acting to open the valve when the water is either too low or too high.
Having thus stated the nature of the said Invention, I will proceed
to describe more particularly in what manner the same is to be performed,
by reference to the accompanying Drawings, in which are represented
the improvements in slide valves, pistons, and safety valves, and apparatus
for preventing accidents in steam boilers above referred to.
of the boiler, but such arrangements do not prevent the loat from
acting to open the valve when the water is either too low or too high.
.
Having thus stated the nature of the said Invention, I will proceed
to describe more particularly in what manner the same is to be performed,
by reference to the accompanying Drawings, in which are represented
the improvements in slide valves, pistons, and safety valves, and apparatus
for preventing accidents in steam boilers above referred to.
DESCRIPTION OF THE DRAWINGS.
Figures 1 to 8 relate to the improvements in slide valves. Fig. 1 is
a plan or horizontal view of a slide valve constructed for two caps or
rings, in which Figure one cap is shewn in its proper position, and the
other removed shewing a quarter of the junk ring; Fig. 2 is a vertical
section through the steam chest of a double cylinder engine in which
one steam chest supplies both cylinders with steam; Fig. 3 is a section
at right angles to Fig. 2; Fig. 4 represents detached the division plate
with the pipes for carrying off any leakage of steam between the back
of the valve and the inside of the cap; Fig. 5 represents the metallic
packing ring detached; Figures 6, 7, and 8 shew an arrangement of the
valves for dispensing with the division plate in the steam chest by
making the two valves work back to back. In these several Figures the
same letters of reference indicate corresponding parts.
A, A, are the steam ports; B, the division plate; C, C, the slide
valves; D, D, the caps or rings applied to the back of the slide valves;
E, E, the junk rings; F, F, the metallic packing rings for keeping the
caps D, D, steam tight.
In describing the action of these improved valves it must be under-
stood that the object of the caps or rings is to prevent the steam in the
steam chest from acting on that part of the back of the valve which is
enclosed within the caps or rings, or more strictly speaking, that area
which is represented by the line of contact between the caps D, D, and
the metallic packing rings F, F. It will be seen from the section of the
cap (Figures 2 and 3) that it is of a conical form both internally and
externally, the object of this form internally being to enable the metallic
packing ring F to act as an expanding ring-in order to press the cap
up to the division plate B (or second valve, as the case may be) when
the steam is shut off from the steam_chest. The circular groove G and

page_text: the holes G in the cap D and the holes E' in the junk ring E (scen
best in Fig. 1) are intended to carry off all steam that may leak between
the surface of the cap D and the division plate B (or second valve, as
the case may be) at a part of the cap that will prevent the occurrence
of a pressure to remove the cap D from off its bearing face. It will
be seen that when the steam is in. the steam. chest the cap D is pressed
up against its bearing face by the steam on the annular area, which is
equal to the difference in diameter between the metallic packing ring F
and the cap D. The caps D. D, are free to move on a fixed centre at
a point H, so as to compensate for unequal wear of the valves or the
cap face or for one side of the valve to lift in case of the engine
priming. The metallic packing ring F is also arranged in such a manner
as to be capable of accomodating itself to the varying position either
of the cap or valve. The said ring is so arranged that the steam presses
it both outwards against the cap D and upwards against the junk
ring E. The said metallic packing ring F is also made conical on its
outer circumference for two reasons. first, in order to reduce the area
of superficial contact between itself and the cap D; and, secondly, in
order to give the steam a larger area to act upon at the bottom of the
ring, so that no amount of leakage on to the top of the same shall be
able to place it in equilibrium, and thus destroy its required action.
The holes, passages, and pipes J and J' in connection with the division
plate B are intended for carrying off any steam that may accumulate
in the cap D. The pipes J' are in communication with the atmosphere,
and are furnished with cocks, so that in the event of any accident
occurring to the caps D these cocks can be closed, the effect of which
will be merely to alter the action or condition of working of the valves
and reduce them to valves of the old construction. The division
plate B is adjusted in position as required at the back end of the steam
chest by means of set screws, as shewn in Fig. 2, and at the front end
by means of two brackets fixed to the steam chest lid, so that when the
steam chest lid is removed the valves can be withdrawn in the usual
way without disturbing the division plate. Another mode of fixing the
division plate is to slide it into a groove provided for it in the top and
bottom of the steam chest.
Figures 6, 7, and 8, shew an arrangement of the valves for dispensing
with the division plate in the steam chest by making the two valves
work back to back. In this case only one valve is required to have a
cap D on the back of it, the other having a plan surface for the cap

page_text: to work against. Provision is made in these valves for allowing any
steam that may accumulate in the cap D to pass out into the atmosphere
by means of the passages J and G in the centre bar of the exhaust ports
and the centre bearing of the valves. The valves and ports are so
arranged in Figures 7 and 8 as to reduce the steam ports in length as
much as possible, and thus reduce the amount of steam used for charging
the ports at each reciprocating movement of the piston. The sides of
the ports are extended in a circular form in order to prevent the
valves from travelling over the faces of the ports at the end of their
stroke.
I will now proceed to state a rule by which to determine the area of
the cap or caps to be applied to the back of the valves. That portion
of a slide valve which does not leave the face of the ports at the end of
the stroke less the area of the steam ports represents the area on the
back of the valve upon which there is a constant pressure, varying
only with the pressure of steam in the boiler. And as it is the object
of these improvements to remove this pressure, it becomes desirable to
point out the following rule for determining the area at the back of any
slide valve from which the said pressure may be removed by the
application of a cap. or caps as herein-before described.
Let A equal the area of the back of any slide valve.
B
"
"
C
"
D
"
35
the area of that part of the valve that leaves the face at
the end of the stroke.
the total area of the steam ports.
the area of the annular cap or caps for removing the
pressure from the back of the valve.
Then the formula will stand as follows:-
A-(B+C)=D.
To take an example, let a slide valve be supposed, measuring eleven
and a quarter inches by nineteen inches. The total area of the back
of this valve would be equal to 213-75 square inches. The area of that
part of the valve which leaves the port faces at the end of the stroke
may be taken in this case as equal to 4375 square inches. The total
area of the two steam ports is equal to 49'50 square inches. Then
213 75-(43'75+49'50) = 120'50 square inches, which shews the area
of the cap or caps to be applied to the backs of the valves, or more
strictly the area to be contained within the circle described by the line
of contact between the cap or caps and the elastic metallic packing ring.

page_text: I will proceed now to .describe the Drawings relating to my
improvements in pistons.
Figures 9 and 10 are a section and underneath plan. Kand K' are
two small valves so arranged that one is in communication with the
steam on one side of the piston and the other with that on the opposite
side thereof at each reciprocating movement of the piston. By means
of these valves the steam is allowed to pass into an annular chamber
enclosed by the ring L, thereby pressing against the inside of the said
ring, and forcing the packing rings M, N, and O outwards against the
inside of the cylinder. It will be seen that owing to the bevilled or
taper form of the rings N and O they become pressed outwards laterally
as well as towards the inside of the cylinder. The segments P, P, are
for "breaking joint" in the packing rings M and O. It will be seen
that the area of the ring L upon the inside of which the steam acts is
much less than that of the bearing surfaces of the packing rings M, N,
and O, and it can be limited as desired just to keep the rings close
against the inside of the cylinder and no more, by which means the
wear and friction are reduced to a minimum. The small valves K
and K' are so arranged as by their respective closing to prevent the
escape of steam from the annular chamber in the piston as it leaves
the cylinder at either end. The said valves are also arranged so that
the annular chamber may receive a fresh supply of steam from either
side of the piston in order to keep up a constant pressure on the packing
rings during the whole time that the engine is at work instead of a
merely intermittent pressure as usual in steam packed pistons. In
some cases it may be preferable to make the ring L in two halves, in
which case the junk ring G may be dispensed with, thereby simplifying
the construction of the piston for small engines.
Figures 11 and 12 shew a sectional plan and elevation of the improved
safety valve with the arrangements for preventing boiler explosions
from either excessive pressure of steam, deficiency of water supply, or
excessive water supply.
The following is an arrangement for preventing an excessive pressure of
steamA is an annular valve with its seating B of corresponding form;
C is a valve fitted at right angles to the valve A for the purpose of
regulating the pressure that is allowed to accumulate in the annular
space or chamber of the valve A, and thereby govern the lifting power

page_text: of the escaping steam upon the valve A. It will be seen that the
steam issuing from the boiler will be caused to pass circuitously both
into the atmosphere and into the chamber of the valve, and that the
greater the pressure allowed to accumulate in this chamber the greater
will be the lifting power of the escaping steam upon the valve A. By
putting greater or less tension on the spiral spring of the valve C this
lifting power can be regulated to the greatest nicety, and thereby admit
of a correspondingly accurate adjustment of the valve A so as to blow
off with steam at any given pressure. It is important that the area of
the valve C should be equal to the area of the annular opening of the
valve seating B. H is a cage for carrying the valve C.
Figures 16 and 17 shew a modification of this improved safety valve
without the annular chamber for obtaining the effect of accumulated
pressure. In this case the increased discharging power of the valve is
due to the escape inwards as well as outwards as in the case above
described, the outlet from the inner portion of the valve being at the
top, as shown in Fig. 17 and by dotted lines in Fig. 16.
The arrangement for detecting a deficiency of water supply is shewn
in Figures 11 and 12. 1 is a float which is worked by the rise and fall
of the level of the water supplied to the boiler. Should the level of
water fall from any cause beyond a given point the weight of the float L
will be caused to act on the lever J and open the valve D, thereby
allowing the steam to exert its full force upon the large end of the ram E
and open the valve F, and thereby allow an amount of steam proportioned
to the area of the outlet Q to blow directly on to the fire and extinguish
it if not at once attended to. The object of the throttle valve G is to
enable the attendant to prevent the steam from putting out the fire
provided that he can at once supply the deficiency of water in the
boiler; but before the attendant can turn the throttle valve G he has
to pass a key through the nut R and break a glass interposed between
the nut and the stem of the throttle valve with the object of serving as
a tell-tale against the attendant when broken. The glass cannot be
replaced without detection, as the nut securing the glass into its place is
screwed home by means of two holes which are afterwards filled with
lead and marked with a private stamp. The valves F and D and the
ram E return to their normal positions in the following order :-When
the water is again pumped to its former level it raises the float Lalong
with it and takes its weight off the lever J, which at once closes the

page_text: valve D, thereby removing the pressure from the large end of the ram E,
and allowing the constant pressure of the steam in the pipe P and the
chest S to act upon the small end of the ram E and close the slide F,
at the same time opening the throttle valve G.
Figures 13 and 14 shew a modification of the tell-tale for dispensing
with the throttle valve G, and which acts in the following manner-
The cock is screwed into the side of the cylinder in which the large
end of the ram E works, and when the steam from any cause acts upon
the ram E as previously described the opening of the cock T by the
attendant will instantly relieve from pressure the large end of the ram E
and allow the pressure exerted upon the small end thereof to return it to
its normal position, but by opening the cock T the tell-tale glass X will
be broken by the action of the steam projecting the ball W against
it. This glass cannot be replaced without detection as previously
described.
The arrangement for detecting excess in the supply of water to the
boiler is shewn in Figures 12 and 15. When the float L is raised by an
excess of water beyond its proper level it will come in contact with the
lever K, which will in turn raise the large end of the lever J and open the
valve D, when exactly the same action will take place with the safety valve
and tell-tale as previously described with reference to the arrangement for
providing against a deficiency of water supply. The bell-crank lever M
is connected with the handle Y at the furnace end of the boiler by means
of the connecting rod N. The use of this bell-crank lever is to enable the
attendant at any time to damp or put out his fire by allowing the steam
from the boiler to blow upon it. By drawing out the rod N the valve D
is opened, and allows the steam to act on the larger end of the ram E,
thereby opening the valve F and admitting steam to blow on to the fire,
in order to damp it or put it out as may be required, and by pushing in
the rod N the valve D is closed without interfering with the tell-tale.
Having thus described the nature of the said Invention, and in
what manner the same is to be performed, I hereby declare that what I
claim as of my luvention is as follows:-
With reference to slide valves I claim,-
First. The construction of the caps or rings applied to the back of the
valves with their internal surfaces made conical as well as their outside,
thereby dispensing with the use of springs by enabling the metallic
packing rings to act as expanding rings in the manner described.

page_text: Secondly. Constructing the metallic packing rings of an excentric
form as represented and described and conical on the outer surface,
thereby preventing the steam from acting on the outer circumference of
the said rings so as to counteract its required expanding pressure on the
inside thereof, and also preventing the steam from acting so as to
interfere with the required contact of the packing rings with the junk
rings.
Thirdly. The screwing of the junk ring or rings on the back of the
valve, as represented and described.
Fourthly. The combination of the caps or rings with the metallic
packing. rings, both constructed as represented and described, by which
arrangement the said caps or rings are caused to move on a centre and
are thereby constantly kept in contact with their bearing surfaces as
required.
And, fifthly. The formation of passages for carrying off leakages of
steam from the spaces between the back of the valves and the division
plate or its equivalent through the said plate, and also the centre bar of
the exhaust ports and the centre bearings of the valves with a pipe or
pipes leading to the atmosphere, also the formation of the ports, as
represented and described.
With reference to pistons I claim, the combination and arrangement of
the parts represented and described, whereby the steam admitted through
the valves on either side of the piston into an annular chamber is caused
to press the metallic packing rings outwards both laterally and against
the inside of the cylinder, as herein-before described.
With reference to safety valves I claim,-
First. The construction of valves of annular form to cover an outlet
for steam of corresponding form, having seatings as described and being
used either alone or in combination with compensating extension valves,
as represented and described.
Secondly. The combination and arrangement of the parts for working
the safety valve or valves, as represented and described.
And, thirdly. The modification of safety valve represented in Figures
16 and 17 and described.
And with reference to apparatus for preventing damage or accidents in
steam boilers I claim,-

page_text: First. The arrangement for detecting a deficiency of water supply, as
represented in Figures 11 and 12 and herein-before described.
Secondly. The arrangement for detecting excess in the supply of
water to the boiler, as represented in Figures 12 and 15 and herein-before
described.
Thirdly. The arrangement for damping or putting out the fire as may
be required, as represented in Figures 11 and 12 and herein-before
described.
And, lastly. The use of a throttle valve as shewn in Figures 11 and 12
or a cock as shown in Figures 13 and 14 for the purpose herein-before
described.
In witness whercof, I. the said Walter Charles Church, have
hereunto set my hand and scal, the Eighth day of April, in
the year of our Lord One thousand eight hundred and sixty-
nine.
Witness,
WILLIAM SPENCE,
8, Quality Court.
W. C. CHURCH. (L.S.)