IMPROVEMENTS IN SPRING SAFETY VALVES AND IN THE ÅRRANGEMENT OF PARTS CONSTITUTING SAME.
Year: 1875

page_text: LETTERS PATENT to John Rochford, of Number 6, Cabra Parade, .
in the County of the City of Dublin, Mechanical Engineer, for the
Invention of "IMPROVEMENTS IN SPRING SAFETY VALVES AND IN THE
ÅRRANGEMENT OF PARTS CONSTITUTING SAME.'
"
PROVISIONAL SPECIFICATION left by the said John Rochford at
the Office of the Commissioners of Patents, with his Petition,
on the 5th October 1875.
I, JOHN ROCHFORD, of Number Six, Cabra Parade, in the County of
3 the City of Dublin, Mechanical Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN SPRING SAFETY VALVES AND IN
THE ARRANGEMENT OF PARTS CONSTITUTING BAMBE," to be as follows, reference
being had to the accompanying Drawing (which is half size, designed
for a pressure of twenty-five pounds to the inch) and to the letters
of reference marked on the Drawing which forms a part of this
Specification :-
A enrine safety valva for marina. locomotive, or stationary boilera.

page_text: which is seated the valve b. The valvo spindle c passes through the
diaphragm plate d; e is the casing or box which contains the spring ƒ;
g is the cup or guard upon which the spring ƒ bears; his a cover or cap
mado to screw into the upper portion ; of the casing e. The cover his
arranged to hold and bear the weight or regaining power of the spring f,
and is so constructed that it can be used for forcing the spring into
position in the casing e.
In some instances the valve spindle c may be provided with a casing
or guard fixed about the centre of the spindle, and inside the spring to
prevent the spring deflecting. The bolts k and are provided with
padlocks. The guard M. is also provided with padlocks to keep the
cover from being unscrewed. R is the easing lever which is carried
by the standard T and works or takes on to the bonnet U, which bonnet
is connected to the valve spindle by the cotter bar V, the cotter being
secured by a padlock; S is a spare lever for use if the spring should 1
break. A, branch leading to waste steam pipe; B, flange for attaching
to boiler; D, branch for condensed water pipe or drain cock.
Upon reference it will be seen that the valve b is kept in position and
weighted by the spiral spring f, which spring bears upon the cup or
guard ŋ which rests on a collar formed on the valvo spindle c.
The 2
diaphragm d serves as a guide for the valve spindle c, and also protects
the spring from the action of the escaping steam. The pressure of the
spring can be regulated by screwing the cap or cover h, for an increased
pressure, further into the casing, the upper portion ; being reduced in
proportion to the additional pressure required. For a reduced pressure 2
the cap or cover / is unscrewed from the casing, and a ring corrc-
sponding in thickness with the distance required for the reduced
pressure is placed between the top of the casing; and the flange on the
cap or cover h.
SPECIFICATION in pursuance of the conditions of the Letters Patont, 30
filed by the said John Rochford in the Great Seal Patent Office
on the 3rd April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ROCHFORD, of 6, Cabra Parade, in the County of the City of Dublin,
Mechanical Engineer, send grooting.
35

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of October, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and
5 successors, give and grant unto me, the said John Rochford, Her
special licence that I, the said John Rochford, my executors, admini-
strators and assigns, or such others as I, the said John Rochford, 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 "IMPROVEMENTS
IN SPRING SAFETY VALVES AND IN THE ARRANGEMENT OF PARTS CONSTITUTING
SAME," upon the condition (amongst others) that I; the said John
Rochford, 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.
IF
'
NOW KNOW YE, that I, the said John Rochford, 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 accom-
5panying three Sheets of Drawings and to the letters of reference marked
thereon. Like letters on the Drawings are used to denote similar
parts :-
Figure 1, Sheet 1, is a sectional elevation of a safety valve constructed
according to my Invention, drawn half size and designed for a pressure
0 of twenty-five pounds to the inch; Figure 2, Sheet 2, is a sectional
elevation of a modified arrangement of safety valve constructed
according to my Invention, drawn full-size and designed for a pressure
of sixty-five pounds to the inch; Figure 8, Sheet 3, is a sectional
elevation of another modified arrangement of safety valve constructed
5. according to my Invention, drawn full size and designed for a pressure
of sixty-five pounds to the inch.
"
-
A spring safety valve for marine, locomotive, or stationary boilers,
constructed according to my Invention, consists of a valve chest'a, in

page_text: which is seated the valve b, constructed with a novel form of lip b¹.
The valve spindle c passes through the diaphragm plate d; c is the
casing or box which contains the spring f; g is the cup or guard upon
which the spring of bears; is a cover or cap made to screw into the
upper portion of the casing e. The cover is arranged to hold and
bear the weight or regaining power of the spring f, and is so constructed
that it can be used for forcing the spring into position in the casing e.
In some instances the valve spindle c may be provided with a casing
or guard fixed about the centre of the spindle and inside the spring, to
prevent the spring deflecting, as shown at c' in dotted lines. The bolts
k and are provided with padlocks. The guard M is also provided with
padlocks to keep the cover from being unscrewed. R is the easing
lever which is carried by the standard T, and works or takes on to the
bonnet U, which bonnet is connected to the valve spindle by the cotter
bar V, the cotter being secured by a padlock;' S is a spare lever for use
if the spring should break; A, branch leading to waste steam pipe;
B, flange for attaching to boiler; D, branch for condensed water pipe
or drain cock.
Upon reference to Figure 1, Sheet 1, it will be seen that the valve 6
is kept in position and weighted by the spiral spring f, which spring
bears upon the cup or guard g, which rests on a collar formed on the
valve spindle c. The diaphragm d serves as a guide for the valve
spindle c, and also protects the spring from the action of the escaping
steam. The pressure of the spring can be regulated by screwing the
cap or cover h for an increased pressure further into the casing, the
upper portion j being reduced in proportion to the additional pressure
required. For a reduced pressure the cap or cover h is unscrewed from
the casing, and a ring corresponding in thickness with the distance
required for the reduced pressure is placed between the top of the
casing; and the flange on the cap or cover h.
The modified arrangement shown at Figure 2, Sheet 2, consists of an
alteration in the shape of the cap or cover h. In this modification the
cap or cover is so arranged that the spring fcan be set in position
without necessitating the long screw, as shown in Figure 1, Sheet 1.
The modified arrangement shown at Figure 3, Sheet 3, consists of a
second alteration in the shape of the cap or cover h, whereby the
screwing of the cap or cover is entirely dispensed with, and in lieu