IMPROVEMENTS IN SAFETY VALVES
Year: 1873

page_text: LETTERS PATENT to Thomas Adams, of the Works, No. 47, Granby..
Row, Manchester, in the County of Lancaster, for the Invention
of "IMPROVEMENTS IN SAFETY VALVES."
PROVISIONAL SPECIFICATION left by the said Thomas Adams at the
Office of the Commissioners of Patents, with his Petition, on the
22nd October 1873.
I, THOMAS ADAMS, of the Works, No. 47, Granby Row, Manchester,
in the County of Lancaster, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SAFETY VALVES," to be as follows:-
-
This Invention has for its object the construction of safety valves in
such manner that the valve may be lifted from its seat for the purpose
of blowing off steam without varying the strain upon the spring, and
also so that the valve may be turned round upon its seat to dislodge any

page_text: substance which may have accidentally entered between the valve and
its seat so as to prevent it closing perfectly.
A further object of my Invention is the formation of the valve and
its seat in such manner that the valve may open a wide passage for the
escape of the steam immediately the pressure to which the valve is
loaded is exceeded, and may close at once and suddenly when the steam
pressure is relieved, and falls perceptably below the pressure at which
the valve opens. For these purposes the coiled spring, by the com-
pression of which the valve is loaded, is arranged in a spring box, and
the spindle which applies the pressure of the spring to the valve passes
up through the spring box. The spring abuts upon a collar on this
spindle and also upon the cover of the spring box. This cover screws
into a deep socket formed for it on the top of the spring box, and it is
made of a wheel-like form or otherwise so that it can be readily turned
and partially unscrewed out of its socket when desired. In the centre
of the cover is a hollow plug through which the spindle passes, and it is
connected with this plug by a key or wedge passed through the plug
and also through a key-way in the spindle, the key-way being slotted for
a distance sufficient to admit of the full lift of the valve. The key or
wedge is secured by a padlock, which prevents the opening of the spring
box.
When the cover of the spring box is partially unscrewed out of its
socket it raises with it the plug at its centre, and the key which passes
through the plug acts directly to lift the spindle and allow the valve to
open without varying the compression of the spring. The extent to
which the valve is raised can be exactly adjusted by screwing the cover
more or less out of its socket.
When it is required to turn the valve upon its scat it is only necessary
to turn the plug in its socket in the cover. With the plug the spindle
turns, and also the valve, the valve being loosely keyed to the spindle at
its lower end.
In order to prevent the steam coming in contact with the spring the
spindle where it passes through the bottom of the spring box is provided
with a packing ring. This ring is made in two parts, which are clipped
together around the spindle by a light steel ring.

page_text: In order that the valve may be sensitive to small variations of pressure
opening widely and closing suddenly I form a flange on the seating
surrounding the valve and enclosing an annular narrow mouthed cavity.
The parts of the valve and its seat I form and proportion in the manner
illustrated by the Drawings annexed.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Thomas Adams in the Great Seal Patent Office
on the 22nd April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ADAMS, of the Works, No. 47, Granby Row, Manchester, in the County
of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Twenty-second day of October, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Adams, Her special license that
J, the said Thomas Adams, my executors, administrators, and assigns,
or such others as I, the said Thomas Adams, my executors, admini-
strators, and assigns, should at any time agree with, and no others from
time to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN SAFETY VALVES,"
upon the condition (amongst others) that I, the said Thomas Adams,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe and
Lascertain 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 Thomas Adams, do hereby declare
the nature of the said Invention, and in what manner the same is to he

page_text: performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention has for its object the construction of safety valves in
such manner that the valve may be lifted from its seat for the purpose
of blowing off steam without varying the strain upon the spring, and
also so that the valve may be turned round upon its seat to dislodge any
substance which may have accidentally entered between the valve and
its seat so as to prevent its closing perfectly.
A further object of my Invention is the formation of the valve and
its seat in such manner that the valve may open a wide passage for the
escape of the steam immediately the pressure to which the valve is
loaded is exceeded, and may close at once and suddenly when the steam
pressure is relieved, and falls perceptably below the pressure at which
tlie valve opens. For these purposes the coiled spring, by the com-
pression of which the valve is loaded, is arranged in a spring box, and
the spindle which applies the pressure of the spring to the valve passes
up through the spring box. The spring abuts upon a collar on this
spindle, and also upon the cover of the spring box. This cover screws
into a deep socket formed for it on the top of the spring box, and it is
made of a wheel-like form or otherwise so that it can be readily turned :
and partially unscrewed out of its socket when desired. In the centre
of the cover is a hollow plug through which the spindle passes, and it is
connected with this plug by a key or wedge passed through the plug
and also through a key-way in the spindle, the key-way being slotted for
a distance sufficient to admit of the full fift of the valve. The key or
wedge is secured by a padlock, which prevents the opening of the spring
box.
.
When the cover of the spring box is partially unscrewed out. of its
socket it raises with it the plug at its centre, and the key which passes
through the plug acts directly to lift the spindle and allow the valve to
open without varying the compression of the spring. The extent to
which the valve is raised can be exactly adjusted by screwing the cover.
more or less out of its socket.
When it is required to turn the valve upon its seat it is only necessary
to turn the plug in its socket in the cover With the plug the spindle

page_text: Figure 1 is a sectional elevation of a lock-up valve constructed as
herein-before described. In this Figure V is the seating of the valve,
with the chamber C formed above it, and V¹ is the valve, the head of
which outside the seating is of a curved form, as shewn, but the lines
both of the head of the valve and of the chamber C may be of other
form, either curvilinear or straight; they must however converge towards
the orifice O. When the valve V₁ is lifted steam is discharged into the
chamber C before issuing out at O, and the pressure existing in the
chamber C exerts its force on the head of the valve V in addition to the
force acting on the valve itself, and by this extra force acting on the
head of V¹, the increasing resistance of the spring is overcome and the
valve is lifted well up from its seat; and if the lines of the chamber C
contract towards O, as shewn, a greater quantity of steam will be dis-
charged then if they did not so converge, while the head of the valve V¹
being curved on its under side in the manner shewn the valve will
return to its seat with a less loss of steam than with any other formation;
also the higher V₁ rises from its seat the under becomes the orifice O.
C¹ is a collar to arrest the lift of valve at any required height; W is a
weight resting on a coned surface to prevent the escaping steam or water
from entering into the chamber containing the spring; S is the spring;
and P is a pintle extending up inside of the spring, the lower end of

page_text: which forms a collar on which the spring rests. Should the spring
break the pintle catches it, prevents the broken ends from passing
each other; the spring thereby performs its functions on the valve
notwithstanding it may be broken. W₁ is a wheel screwed into the top
of the spring box or chamber Cu". The boss of the wheel W' presses on
the spring and puts the load on the valve. It also acts as herein-before
described as easing gear with which to ease or blow off the steam from
the boiler. W is another hand wheel with which to turn the valve
round on its seat in case of dirt getting in between the faces; and K is
a cotter, through the point of which the padlock passes. These wheels
may be either hand, or geared, or friction wheels, or worm and wheel or
skew wheels. This system of casing gear does not put any extra strain
on the spring beyond the load on the valve, for on unscrewing W¹ the
whole mechanism comes back just as it now stands until arrested by C¹,
and on screwing home W₁ shoulder and shoulder with C" the valve is
again in position with its load on, while W¹ and C" being shoulder and
shoulder no extra weight can be put on the valve without cutting some-
thing off either one or the other, and if in case of wear of valve anything
requires to be taken off it can be taken off the shoulder of C or W'.
Instead of wheels handles may be used to perform the same functions
either fixed or removable.
Figure 2 is a section taken through A, B, and C, D, and shows a pair
of valves in one box formed with side ports P and P for the escaping
steam, and with metal M in front of waste steam pipe to prevent any
person from tampering with the valves when waste steam pipe is off,
and also for preventing the two opposite currents of steam from meeting
in opposite directions.
At Figure 3 is shewn an arrangement in which a valve constructed as
above described with a chamber C above the valve seating is used to
control the opening of another and larger valve for the purpose of giving
a high lift to the valve and a quick return to its seat.
The valve V is loaded to blow off say at 100 lbs., whilst the larger
valve V¹ is loaded to blow off at a higher pressure, say at 102 lbs. On
V. rising from its scat the steam escaping into the chamber C has a free
communication with P by the passage X, and exerts its force on the
under side of P, which is a steam-tight steam-packed piston made tight

page_text: by the packing ring R, the result being that V is lifted well up from its
seat a height equal to one-fourth its diameter or more if required..
Immediately that V' has reduced the pressure in the boiler to the desired.
amount V closes, and the steam acting under P now returns by X and
| escapes through the orifice O into the atmosphere, and V₁ by reason of
its extra load of 2 lbs. now falls to its seat. By this combined action, of
2 or more valves a boiler can be relieved instantaneously in one-fourth
part of a second of time.
N is a packing ring inserted in the spindle to prevent the escape of
steam; S is a shield to protect the thread on boss of W¹ when screwed
back to blow off steam; R¹ is a packing ring in one or more pieces with
a ribbon steel spring around it to keep it close to spindle to prevent
steam or water passing in beside the spring; J is a ring to keep R¹ in its...
place; N¹ is a nut with which to compress spring; and L is a lever with
which to blow off or ease the valves. The extra weight on the valve V'
may be of any desired amount. The bottom of the column C, in:
Figure 3, is made to form a cylinder in which P is to work, and the
spring rests on P.
T forms the bottom of the cylinder, and is cast with the box in which
the valves are, but in cases where the valve has to come out and go in
from a vertical direction then a loose plate L may be substituted for T,
as shewn at Figure 7, and be made fast by the same bolts which fasten
the column to the base, or the plate may be screwed into C or T.
At Figure 7 is also shewn another mode of protecting the spring from
steam issuing from the valve. In this arrangement there is no packing
around the spindle, but in place thereof are air chambers C, C¹. Should
any steam pass the clearance allowed the spindle at L it enters the
chamber C, which is provided with exit holes a, a, for the ready escape
of the steam, and an outlet H for any condensed steam to pass away.
Should any steam pass from the chamber C into C₁ it is free to escape
therefrom by the holes a¹, a. The chamber or box containing the spring
is above these chambers.
Figure 4 is a plan of Figure 3, through A, B. Figure 5 shews a
modification of the above arrangement. In this modification R is a
concentric ring around the valve with packing rings N, N, with which
to keep it steam-tight in the annular chamber in which it is received,

page_text: 7. The combining with the easing and blow-off wheel W' a shield S
to protect its screw-threaded boss, substantially as herein described.
8. The arrangements herein described and shewn at Figures 1, 3,
and 7 for preventing steam issuing from the valve coming into contact
with the spring.
In witness whereof, I, the said Thomas Adams, have hereunto set
my hand and seal, this Twentieth day of April, in the year of our
•
Lord One thousand eight hundred and seventy-four.