IMPROVEMENTS IN THE CONSTRUCTION AND FITTING UP OF SAFETY. VALVES FOR STEAM BOILERS OR GENERATORS
Year: 1867

page_text: Filed 20th March 1879.
[NEWTON'S PATENT.]
In the Matter of a Patent granted to ALFRED VINCENT NEWTON, of the
Office for Patents, 66, Chancery Lane, in the County of Middlesex,
Mechanical Draughtsman, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION AND FITTING UP OF SAFETY. VALVES FOR STEAM BOILERS
OR GENERATORS." (A communication from abroad by George William
Richardson, of Troy, in the State of New York, United States of America),
bearing date the 5th day of September 1867, No. 2520, and which said
Letters Patent and all interest therein have been duly assigned to and are
now vested in Thomas Adams, of the Works of the "Ant" and the
"Bee," West Gorton, Manchester, in the County of Lancaster.
DISCLAIMER proposed to be entered by the said Thomas Adams as such Assignee
as aforesaid, pursuant to the Statutes in that case made and provided.
Whereas I have been advised that certain claims made in the Specification of the
said Letters Patent are of doubtful validity: And whereas the subject matter of
these claims is not of great importance, and I do not wish to retain any claim in
respect of the same:
I therefore for these reasons desire to disclaim, and I do hereby disclaim from the
Specification by striking out the paragraphs commencing at page 3, line 6, of the
Specification as it is printed by Her Majesty's Printers with the words "The
"Invention further," and ending at line 20 on the same page with the words
"the boiler." Also by striking out the paragraph commencing at page 5, line 7,
with the words "The manner of," and terininating at line 17 on the same page with
the words "fastening nut K" By inserting after the word "that" on page 5,
line 43, the words "no claim is made to what has been herein-before described or is
contained in the Drawings annexed, except or otherwise than in the two claiming'
clauses herein-after following, that is to say." Also by striking out the second
and the third claiming clauses, commencing at page 5, line 48, with the words.
Price Ad

page_text: "in combination," and terminating on the same page at line 55 with the words
"And lastly.
And in order that the effect of this Disclaimer may be better understood, I annex
a copy of the Specification as it will appear when such Disclaimer has been made
as aforesaid.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Vincent Newton in the Great Seal Patent Office on the 5th March
1868.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVEMENTS IN THE CON-
STRUCTION AND FITTING UP OF SAFETY VALVES FOR STEAM BOILERS OR GENE-
RATORS." A communication.
This Invention relates, firstly, to safety valves which are formed with a surface
outside of or beyond. the ground joint for the escaping steam to act against and
keep them open until the pressure of the steam in the boiler shall have fallen below
the pressure required to open such valves. It is now proposed to apply to such
valves a means of regulating or adjusting the area of the aperture for the escape of
the steam beyond the surface outside of the ground joint, that the valve may be set
to be closed by any desired pressure below the pressure required to open it.
The last part of the Invention relates to a means by which the valve can be
adjusted to open at any required pressure, and then enclosed and locked up so
that the adjustment cannot be changed except by the person having charge of the
key.
In Sheet 1 of the Drawings Fig. 1 is a vertical section of the safety valve and its
connections taken in the plane of the axis of the valve stem; Fig. 2 is a horizontal
section taken in the plane of the line A, a, of Fig. 1; and Fig. 3 is another hori-
zontal section at the line B, b, of Fig. 1.
a represents the valve seat, which is to be attached to a steam boiler or generator
in the usual or any other suitable manner, and which is formed in the usual manner
with a bevilled seat for the valve b, fitted thereto by what is well known as a ground
joint. The valve is formed with wings e in the usual manner, properly fitted to the
cylindrical bore of the valve seat to act as guides. It is cast or otherwise formed with
an enlargement d at the junction of the wings, and extending down about one-third
of the way from the lower end of the wings, so that a central hole may be drilled
therein to receive a rod or stem e, the lower end of which is suitably formed to rest
as a pivot on the centre of the bottom of the said hole, so that no portion of the rod
which is of less diameter shall touch to make friction. A short distance above the
valve the said rod e is formed with a flat and circular disc-like projection f, on
which bears the lower end of a helical spring g, which surrounds the rod without
touching; this spring is held down to make the required pressure on the valve by
a cross head h, held in place by nuts i, i, tapped on the upper ends of two rods,
from a plate k below a flange of the valve seat; the upper end of the valve rod or
stem e plays in a central hole in the cross head h, without touching. By reason of
the spring g bearing on the disc of the rod e, the lower end of which bears centrally
on the valve at a considerable distance below the bevilled seat, it results that the
valve when moving up and down cannot deviate from a true line, and that neither
of the wings can be made to chafe or bind in the bore of the valve seat, and it
follows also that the valve rod when once placed centrally in the hole in which it
plays in the cross head h will move up or down without touching. It is well
known that safety valves as heretofore made frequently fail to open when the
steam goes beyond the pressure to which it is loaded because of undue friction and
binding of the parts, and this is effectually prevented by the arrangement herein-
above described. When used on locomotive boilers of coal-burning engines, or in
other places where ashes, smoke, dust, &c., accumulate, to prevent such impurities
from getting into the hole in the valve in which the valve rod or stem rests, the
said rod may be provided with a sleeve having a flange at the upper end resting on
i

page_text: the upper surface of the valve, as represented by red lines in Fig. 1. It is desirable
that so soon as the pressure of steam in the boiler or generator reaches the point at
which it should be relieved, the safety valve should open wide for the free escape
of steam, and that the valve should remain open until the pressure in the boiler is
reduced below the pressure by which the valve was opened; and it is desirable also
that a safety valve should be so organised that the engineer may be able to adjust
it so that it will close at any desired number of pounds pressure below the pressure
at which it will be opened. To accomplish these results is the main object of the
present Invention.
8
To the upper surface of the valve I secure a cap plate or annulus m, formed with
a downward projecting flange n at its outward periphery leaving an annular
space o all around between the outer periphery of the valve and the inner periphery
of the flange n of the said cap. The upper surface of the valve seat a is extended
all around a little beyond the outer periphery of the flange n of the cap, leaving an
annular flat surface p surrounded by an upward projecting rim q, the plane of the
upper edge of which when the valve is closed extends a short distance above the
plane of the lower edge of the flange n of the cap. The cap plate ma is connected
with the top of the valve by studs r, r, or cast with it in such manner as to leave
an open space s between the two for the passage of steam to the central aperture t
in the cap, through which steam can escape when the valve is lifted from its seat.
The central aperture is surrounded by a projecting cylindrical flange threaded on
the outside, to which is fitted a threaded ring u that can be turned up or down to
any desired elevation and there secured by a set screw v. The disc-like projection f
on the valve, rod, or stem e extends over the said central aperture t in the cap
plate m, and at such an elevation that the upper edge of the adjustable ring can be
set in contact with it or let down so far below it as to leave sufficient space for the
free escape of steam. From the foregoing it will be seen that when the pressure of
steam in the boiler or generator becomes sufficient to lift the valve from its seat it
acts against the surface of the annular space o between the bevil of the valve seat
and the downward projecting flange n of the cap to assist in lifting and holding up
the valve. If the projecting rim q was in the same plane with the lower edge of
the flange n the diameter of these parts being greater than that of the valve seat
on the lifting of the valve and cap the area of the opening between the flange n of
the cap and the projecting rim q would be greater than the area of the opening
between the valve and its seat just in proportion as the diameter of the one is
greater than the other, and the steam escaping from the valve would pass
unchecked between the flange n and rim q and would not exert any force
against the surface of the annular space o, but as the rim q extends above the
lower edge of the flange n of the cap plate it follows that the aperture between
the valve and its seat by the lifting of the valve is always greater than the
aperture between the flange n and the rim q, and hence the escaping steam by
its elastic force will act against the surface of the annualar space o to assist in lifting
and holding up the valve until the pressure in the boiler or generator falls below
the pressure by which the valve was first opened. The difference between the
pressure against which the valve will close and the pressure by which it will be
opened will depend upon the distance between the outer periphery of the flange n
of the cap plate and the inner periphery of the projecting rin q. To render this
adjustable the area of the aperture for the escape of steam beyond the valve seat
must be adjustable. This is effected by raising or lowering the ring 1, if it be set
to its lowest position the steam escaping from the valve will be free to escape.
between the top of the valve and the cap through the central aperture, and thence
between the upper edge of the ring u and the disc f without materially aiding to
lift or hold up the valve; but by setting the ring u nearer to the under surface of
the disc f and thereby reducing the space for the escape of steam it will be caused
to act by its elastic force in the annular space o of the cap plate, and thus assist in
lifting the valve and holding it up. I have described and represented this as the
simplest mode of adjusting the area of the aperture for the escape of the steam

page_text: after it passes the valve seat; but it will be obvious that the same result may be
attained by equivalent means, such, for instance, as making the rim q in adjustable
segments so that its diameter could be increased or diminished, but this would be
more complicated than the mode first and fully described.
The means for adjusting the valve to open at any required pressure is represented
at Figures 5 and 6, Fig. 5 being a vertical section of the valve and its fittings,
and Fig. 6 a horizontal section taken in the plane of the line A, a, of Fig. 5.
these Figures a³ represents the valve seat; 63, the valve; c³, the valve stem; and d³
the helical spring for holding down the valve. Instead of rods for holding the bar
or cross head which guides the upper end of the valve stem a cylindrical case e³ is
substituted, which case is secured to the boiler by its lower end fs; the valve seat a³
is fitted to the inside of this case. At the upper end the inner periphery of the case
is threaded to receive a threaded ring gs, formed with cross arms h³ with a central
hole to receive and guide the upper end of the valve stem, the cross arms of this ring
bear on the upper end of the helical spring d³, so that by turning the ring g³ to the
right or to the left, the tension of the spring on the valve can be increased or decreased
at pleasure. The upper end of the case e³ and of the ring g³ are graduated to the
ranges of pressure, so that the tension of the spring can be readily adjusted to any
desired pressure; the whole is then enclosed by a cap plate h secured to the upper
end of the case by screw bolts 3, 3, and unto 3, 3, the cap plate being formed with
a cylindrical flange, which rests on the upper surface of the ring g³, to insure its
being held down. The upper part of the screw bolts 23, 28, are morticed, as repre-
sented, to permit a locking bar 13 to pass through; it has a head m³ at one end, and
a hole n³ at the other to receive the hasp of a padlock; when thus locked, there will
be an effectual bar put to the surreptitious re-adjustment of the valve; the case es
is formed with a branch pipe os above the valve for the escape of steam.
Having now set forth the nature of the Invention of "Improvements in the
Construction and Fitting up of Safety Valves for Steam Boilers or Generators,"
and explained the manner of carrying the same into effect, I wish it to be under-
stood that no claim is made to what has been herein-before described or is contained
in the Drawings annexed, except or otherwise than in the two claiming clauses
herein-after following, that is to say, under the above in part recited Letters
Patent, I claim,―
First. Applying to safety valves constructed with an overlapping rim as above
described, the means herein described, or the equivalent thereof for regulating or
adjusting the area of the passage for the escape of the steam beyond the bevil or
equivalent seat, substantially as and for the purpose described.
Secondly. The combination of the valve and seat, the surrounding case, the ring
for holding down the spring and regulating its tension on the valve, the enclosing
cap, and the means or the equivalent thereof for locking up the valve, substantially
as and for the purpose specified.
In witness whereof, I, the said Thomas Adams, have hereunto set my hand
and seal, this Twenty-third day of February, One thousand eight hundred
Signed, sealed, and delivered by the
above-named Thomas Adams in
the presence of
CHAS. J. COOPER,
Solicitor,
Manchester.
THOMAS ADAMS. (L.S.)
I hereby grant my fiat, giving leave to the above-named Thomas Adams, as
assignee of the Letters Patent, to file in the Great Seal Patent Office, with the Speci-
fication to which the same relates, the above written Disclaimer and Memorandum

page_text: of Alteration, upon the conditions that the names of the parties and dates of the
contracts in existence at this date be given by the opponent or his solicitors to the
applicant or his solicitors within ten days from the date hereof. No action to be
brought in respect of anything done or to be done under any existing contracts.
Temple January 11th 1879
HARDINGE GIFFARD.
I hereby certify that the conditions mentioned in the fiat attached to Disclaimer
No. 2520/67 have been complied with. That the names of the parties having con-
tracts have been supplied, and that an undertaking has been given by Mr. Adams
that he will not bring any action in respect of anything done or to be done under
such contracts. I therefore order and direct that the papers be placed upon the
file.
In the matter of a Patent granted to Alfred Vincent Newton, of the Office for
Patents, 66, Chancery Lane, in the County of Middlesex, Mechanical Draughtsman,
for the Invention of "Improvements in the Construction and Fitting Up of Safety
"Valves for Steam Boilers or Generators." (A communication from abroad by
George William Richardson, of Troy, in the State of New York, United States of
America), bearing date the 5th day of September 1867, No. 252007, and which
said Letters Patent and all interest therein have been duly assigned to and are now
vested in Thomas Adams, of the Works of the "Ant" and the "Bee," West Gorton,
Manchester, in the County of Lancaster,-
I, the above-named Thomas Adams, do hereby undertake that I will not bring
any action in respect of anything done or to be done under the contracts, parti-
culars of which have been furnished by William John Coe, and which are as
follows:-
1. 17th June 1878.
2 prs. 6" valves.
S. S. "Glamorgan."
2. 8th January 1879.
4 prs. 6" valves, &
1 single 3" valve.
S. S. "Stad Haarlem."
Dated this 22nd day of February 1879.
Geo. Hepburn, Esq., Liverpool.
Rait & Gardner, London.
THOMAS ADAMS.

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical Draughts-
man, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION AND
FITTING UP OF SAFETY VALVES FOR STEAM BOILERS OR GENERATORS."—A
communication from abroad by George William Richardson, of Troy, in
the State of New York, United States of America.
Sealed the 8th November 1867, and dated the 5th September 1867.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition, on
the 5th September 1867.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Mechanical Draughtsman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION AND
FITTING UP OF SAFETY VALVES FOR STEAM BOILERS OR GENERATORS," to be as
follows:
In constructing safety valves for and adapting them to steam boilers, it is
desirable to ensure that so soon as the pressure of steam in the boiler or
generator reaches the pressure at which it should be relieved, the safety valve

page_text: shall open wide for the free escape of steam, and that the valve shall remain
open until the pressure in the boiler is reduced below the pressure by which
the valve was opened. And it is desirable also that a safety valve should be
so organized that the engineer may be able to adjust it so that it will close at
any desired number of pounds pressure below the pressure at which it will be
opened. To accomplish these results is the main object of the present
Invention.
In order to provide a more free escape for the steam than can be obtained
by safety valves as heretofore constructed, and to insure the keeping of the
valve open until the pressure of the steam in the boiler shall have fallen below
the pressure which would be required to open the valve, the valve is formed
with a surface outside of the ground joint for the escaping steam to act against ;
this extended surface is produced by a cap plate secured to or cast with the
valve in such manner as to leave an open space between the two for the passage
of steam to a central aperture in the cap, through which steam can escape when
the valve is lifted from its seat; this central aperture is surrounded by a pro-
jecting cylindrical flange threaded on the outside, to which is fitted a threaded
ring that can be turned up or down to any desired elevation and there secured
by a set screw. A disc-like projection on the valve rod extends over the said
central aperture in the cap plate, and at such an elevation that the upper edge
of the adjustable ring can be set in contact with it or let down so far below it
as to leave sufficient space for the free escape of steam. When a spring is
used to hold down the valve the increased surface obtained for the steam to
act against will ensure a counteracting force corresponding, or nearly so, with
the increasing tension of the spring as the valve is forced up. By this means
the regulating or adjusting of the area of the aperture for the escape of the
steam beyond the surface outside of the ground joint may be effected at
pleasure. To prevent the guides and stem of a valve, controlled by a spring
from binding, and thereby impeding the movements of the valve it is now
proposed that the pintle or stem which receives the tension of the spring shall
bear on the valve so far below the plane of the valve seat that the force of the
spring shall always be communicated to the valve in the direction of its
axis.
The Invention further relates to an improvement by which the loud noise
produced by the sudden opening of a safety valve is materially reduced, which
noise is very objectionable, particularly on locomotive engines, and which is due
to the fact that when first opened the valve is thrown up-too high above its
seat and with great force.

page_text: The improvement consists in combining with the valve and its seat an
adjusting screw so located that when the valve is forced up its stem comes in
contact therewith and prevents the valve from being opened beyond the extent
required for the relief of the boiler.
A further improvement relates to a means by which the valve can be
adjusted to open at any required pressure and then enclosed and locked up so
that the adjustment cannot be changed except by the person having charge of
the key. Instead of rods for holding the bar or cross head, which guides the
upper end of the valve stem, a cylindrical case is substituted which is to be
secured to the boiler by its lower end. The yalve seat is fitted to the inside
of this case. At the upper end the inner periphery of the case is threaded
to receive a threaded ring formed with cross arms to receive the pressure of
the valve spring and with a central hole to guide the upper end of the valve
stem. By turning the ring the tension of the spring on the valve can be
increased or decreased at pleasure. A cap plate secured to the upper end of
the case by screw bolts and nuts bears upon the upper surface of the ring to
insure its being held down. The screw bolts are mortised to permit a
locking
bar to pass, through, which bar is secured by a padlock.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Vincent Newton in the Great Seal Patent Office
on the 5th March 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Mechanical Draughtsman, send greeting.
me,
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of September, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me
the said Alfred Vincent Newton, Her special, licence that I, the said Alfred
Vincent Newton, my executors, administrators, and assigns, or such others as I
the said Alfred Vincent Newton, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time, and at all times
thereafter during the term therein expressed, should and lawfully, might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for

page_text: "IMPROVEMENTS IN THE CONSTRUCTION AND FITTING UP OF SAFETY VALVES FOR
STEAM BOILERS OR GENERATORS," being a conimunication to me from abroad,
upon the condition (amongst others) that I, the said Alfred Vincent
Newton, 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 Alfred Vincent Newton, do hereby
declare the nature of the 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 Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):
:-
It is now
This Invention relates, firstly, to safety. valves which are formed with a
surface outside of or beyond the ground joint for the escaping steam to act
against and keep them open until the pressure of the steam in the boiler
shall have fallen below the pressure required to open such valves.
proposed to apply to such valves a means of regulating or adjusting the area
of the aperture for the escape of the steam beyond the surface outside of the
ground joint, that the valve may be set to be closed by any desired pressure
below the pressure required to open it.
The Invention further relates to means for preventing the guides and stem
of a valve controlled by a spring from binding, and thereby impeding the
movements of the valve, and this part of the Invention consists in making
the pintle or stem which receives the tension of the spring bear on the valve
so far below the plane of the valve seat that the force of the spring shall
always be communicated to the valve in the direction of its axis.
The Invention also relates to an improvement by which the loud noise
produced by the sudden opening of a safety valve is materially reduced, which
noise is very objectionable, particularly on locomotive engines, and which is
due to the fact that when first opened the valve is thrown up too high above
its seat and with great force.
The improvement consists in combining with. the valve and its seat-an
adjusting screw so located that when the valve is forced up its stem comes in
contact therewith and prevents the valve from being opened beyond the extent
required for the relief of the boiler.
The last part of the Invention relates to a means by which the valve can be

page_text: adjusted to open at. any required pressure, and then enclosed and locked up
so that the adjustment cannot be changed except by the person having charge
of the key.
In Sheet I. of the Drawings, Fig. 1 is a vertical section of the safety valve
and its connections taken in the plane of the axis of the valve stem; Fig. 2 is a
horizontal section taken, in the plane of the line A, a, of Fig. 1; and Fig. 3
is another horizontal section at the line B, b, of Fig. 1.
FL.
a represents the valve seat which is to be attached to a steam boiler or
generator in the usual or any other suitable manner, and which is formed in
the usual manner with a bevilled seat for the valve 6 fitted thereto by what is
well known as a ground joint. The valve is formed with wings c in the usual
manner properly fitted to the cylindrical bore of the valve seat to act as guides;
it is cast or otherwise formed with an enlargement d at the junction of the
wings, and extending down about one-third of the way from the lower end of
the wings, so that a central hole may be drilled therein to receive a rod or stem e,
the lower end of which is suitably formed to rest as a pivot on the centre of the
bottom of the said hole, so that no portion of the rod which is of less diameter
shall touch to make friction. A short distance above the valve the said rod e
is formed with a flat and circular disc-like projection f on which bears the
lower end of a helical spring 9 which surrounds the rod without touching; this
spring is held down to make the required pressure on the valve by a cross
head h held in place by nuts i, i, tapped on the upper ends of two rods j, j,
from a plate k below a flange 7 of the valve seat; the upper end of the valve
rod or stem e plays in a central hole in the cross head h without touching.
By reason of the spring g bearing on the disc of the rod e, the lower end of
which bears centrally on the valve at a considerable distance below the bevilled
seat, it results that the valve when moving up and down cannot deviate from
a true line, and that neither of the wings can be made to chafe or bind in the
bore of the valve seat, and it follows also that the valve rod when once
placed centrally in the hole in which it plays in the cross head h will
move up. or down without touching. It is well known that safety valves
as heretofore made frequently fail to, open when the steam goes beyond the
pressure to which it is loaded because of undue friction and binding of the
parts, and this is effectually. prevented by the arrangement herein-above
described. When used on locomotive boilers of coal burning engines or in
other places where., ashes, smoke, dust, &c. accumulate, to prevent such
impurities from getting into the hole in the valve in which the valve rod or
stem rests, the said. rod may be provided with a sleeve having a flange at the

page_text: upper end resting on the upper surface of the valve; as represented by red
lines in Fig. 1. It is desirable that so soon as the pressure of steam in the
boiler or generator reaches the point at which it should be relieved the safety
valve should open wide for the free escape of steam, and that the valve should
remain open until the pressure in the boiler is reduced below the pressure
by which the valve was opened, and it is desirable also that a safety valve
should be so organized that the engineer may be able to adjust it so that it
will close at any desired number of pounds pressure below the pressure at
which it will be opened. To accomplish these results is the main object of
the present Invention.
To the upper surface of the valve I secure a cap plate or annulus m formed
with a downward projecting flange n at its outward periphery, leaving an
annular space o all around between the outer periphery of the valve and the
inner periphery of the flange n of the said cap. The upper surface of the valve
'seat a is extended all around a little beyond the outer periphery of the flange n
of the cap, leaving an annular flat surface p surrounded by an upward pro-
jecting rim q, the plane of the upper edge of which when the valve is closed
extends a short distance above the plane of the lower edge of the flange n of
the cap.
'The cap plate m is connected with the top of the valve by studs r, r,
or cast with it in such manner as to leave an open spaces between the two
for the passage of steam to the central aperture t in the cap, through which
'steam can escape when the valve is lifted from its seat. This central aperture
is surrounded by a projecting cylindrical flange threaded on the outside, to
which is fitted a threaded ring u that can be turned up or down to any
desired elevation and there secured by a set screw v. The disc-like pro-
jection on the valve rod or stem e extends over the said central aperture t in
the cap plate m and at such an elevation that the upper edge of the adjustable
ring can be set in contact with it or let down so far below it as to leave
sufficient space for the free escape of steam. From the foregoing it will be
seen that when the pressure of steam in the boiler or generator becomes
sufficient 'to lift the valve from its seat it acts against the surface of the
annular space o between the bevil of the valve seat and the downward
projecting fange n of the cap to 'assist in lifting and holding up the valve.
If the projecting rim 9 was in the same plane with the lower edge of the
Hange n, the diameter of these parts being greater than that of the valve
seat, on the lifting of the 'valve and cap the area of the opening between the
Hange
n of the cap and the projecting rim q would be greater than the area of
the opening between the valve and its seat, just in proportion as the diameter
L

page_text: of the one is greater than the other, and, the steam escaping from the valve
would pass unchecked between the flangen and rim q and would not exert
any force against the surface of the annular space o, but as the rim q extends
above the lower edge of the flange n of the cap plate it follows that the
aperture between the valve and its seat by the lifting of the valve is always
greater than the aperture between the flange n and the rim q, and hence the
escaping steam by its elastic force will act against the surface of the annular
space o to assist in lifting and holding up the valve until the pressure in the
boiler or generator falls below the pressure by which the valve was first
opened. The difference between the pressure against which the valve will
close and the pressure by which it will be opened will depend upon the
distance between the outer periphery of the flange n of the cap plate and the
inner periphery of the projecting rim q. To render this adjustable the area
of the aperture for the escape of steam beyond the valve seat must be
adjustable. This is effected by raising or lowering the ring u; if it be set to
its lowest position the steam escaping from the valve will be free to escape
between the top of the valve and the cap, through the central aperture, and
thence between the upper edge of the ring us and the disc f without materially
aiding to lift or hold up the valve; but by setting the ring u nearer to the
under surface of the disc f, and thereby reducing the space for the escape of
steam, it will be caused to act by its elastic force in the annular space o of the
cap plate, and thus assist in lifting the valve and holding it up. I have described
and represented this as the simplest mode of adjusting the area of the aperture
for the escape of the steam after it passes the valve seat, but it will be
obvious that the same result may be attained by equivalent means, such for
instance as making the rim q in adjustable segments so that its diameter
could be increased or diminished, but this would be more complicated than
the mode first and fully described.
:
The manner of regulating the extent of motion of the valve to prevent the
loud noise before referred to is shewn in Sheet II. of the Drawings, wherein
Fig. 4 is an elevation with the valve in section; in this Figure a² represents
the valve seat; b, the valve; c, the valve stem; d, the spring for holding down
the valve; 'e, e, the rods or standards; and f the cross bar or guide for the
upper part of the valve stem, and forming the upper bearing for the spring,
and the height of which can be adjusted by the nuts g³, g, and ha, ha, on the
rods to regulate the force of the spring on the valve. This cross bar extends
some distance above the upper end of the valve stem as at 22, and is there pro-
vided with a set screw in line with the valve stem, and which can be set to

page_text: j
stop the upward motion of the valve at any point desired, and there fixed by
a fastening nut k². The means for adjusting the valve to open at any required
pressure is represented at Figures 5 and 6; Fig. 5 being a vertical section of
the valve and its fittings, and Fig. 6 a horizontal section taken in the plane
of the line A; a, of Fig. 5. In these Figures a represents the valve seat; 63,
the valve; c, the valve stem; and the helical spring for holding down the
valve. Instead of rods for holding the bar or cross head which guides the
upper end of the valve stem, a cylindrical case e³ is substituted; which case is
secured to the boiler by its lower end f³; the valve seat a³ is fitted to the
inside of this case. At the upper end the inner periphery of the case is
threaded to receive a threaded ring gå formed with cross arms h³, with a
central hole to receive and guide the upper end of the valve stem
the cross
arms of this ring bear on the upper end of the helical spring d³, so that by
turning the ring g³ to the right or to the left the tension of the spring on the
valve can be increased or decreased at pleasure. The upper end of the
case and of the ring gare graduated to the ranges of pressure, so that the
tension of the spring can be readily adjusted to any desired pressure; the
whole, is then enclosed by a cap plate h* secured to the upper end of the case
by screw bolts, 3, and nuts 3, 3, the cap plate being. formed with a cylin-
drical flange which rests on the upper surface of the ring g³ to insure its
being held down. The upper part of the screw bolts 2, 3, are morticed, as
represented, to permit a locking bar to pass through, it has a head m³ at
one end and a hole n³ at the other to receive the hasp of a padlock; when
thus locked there will be an effectual bar put to the surreptitious readjustment
of the valve; the case,e³ is formed with a branch pipe os above the valve for
the escape of steam.
Having now set forth the nature of the Invention of." Improvements in
the Construction and Fitting up of Safety Valves for Steam Boilers or
Generators," and explained the manner of carrying the same into effect,
I wish it to be understood that under the above in part recited Letters Patent
I claim,
First, applying to safety valves constructed with an overlapping rim. as
above described the means herein described, or the equivalent thereof, for
regulating or adjusting the area of the passage for the escape of steam
beyond the bevil, or equivalent seat, substantially as and for the purpose
described.
Secondly, in combination with a safety valve held down by the tension of a
spring the employment of a rod or stem which receives the tension of the

page_text: spring and imparts it to the valve by a pivot or equivalent bearing materially
below the valve seat, substantially as and for the purpose described.
Thirdly, combining with the valve the spring and the valve stem the set
screw for regulating the height beyond which the valve shall not be lifted,
substantially as described.
And, lastly, the combination of the valve and seat, the surrounding case,
the ring for holding down the spring and regulating its tension on the valve,
the enclosing cap, and the means or the equivalent thereof for locking up the
valve, substantially as and for the purpose specified.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto
set my hand and seal, the Fifth day of March, in the year of our
Lord One thousand eight hundred and sixty-eight.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.s.)