A SPRING SAFETY VALVE FOR MARINE, LOCOMOTIVE, AND STATIONARY BOILERS
Year: 1873

page_text: LETTERS PATENT to John Rochford, of Number Six, Cabra Parade,
in the County of the City of Dublin, Mechanical Engineer, for
the Invention of "A SPRING SAFETY VALVE FOR MARINE, LOCOMOTIVE, AND
STATIONARY BOILERS."
PROVISIONAL SPECIFICATION left by the said John Rochford at
the Office of the Commissioners of Patents, with his Petition, on
the 21st April 1873.
I, JOHN ROCHFORD, of Number Six, Cabra Parade, in the County of
the City of Dublin, Mechanical Engineer, do hereby declare the nature
of the said Invention for "A SPRING SAFETY VALVE FOR MARINE, LOCOMOTIVE,
AND STATIONARY BOILERS," to be as follows:-
Spring safety valve for marine locomotive and stationary boilers con-
sisting of a casing with cover secured by bolts and nuts, and one or
more of these bolts having a padlock so that the cover cannot be taken
off without unlocking the padlock; inside casing is a feather or spindle
valve having a cylinder on the back of valve for the purposes of

page_text: protecting the spring from the escaping steam, keeping the spring in
proper position, and if the spring should break the top of cylinder
would come into contact with the under side of the nut in the cover and
prevent the valve from coming out of its seating. In the cover is a
nut into which screws a piston and cylinder to a head on top of cylinder
for working the piston to compress the spring contained in cylinder
on back of valve, the head coming into contact with top of nut in cover
prevents the pressure being increased beyond that for which the valve
was allowed to carry liners to be used between head of piston and
top of spiral spring, so that by taking out these liners the pressure can
be reduced, or should it be required to reduce the pressure without
taking off the cover it can be done by the unlocking of the padlock, in
the key that passes through the bonnet and screwing back the piston
and cylinder, the bonnet can be again put on and a narrower key used.
The spiral spring is confined in the cylinder on back of valve, and com-
pressed by the piston which is attached to the cylinder passing through
the cover; the easing gear is a lever having the fulcrum between the
valve spindle and the rod for weighing on to lift or ease the valve; the
joints are bushed with brass or other anti-corrosive metal to the pins
made or lined with brass, &c., so that should the valve be out of use for
a lengthened period the joints would not be rusted or corroded, the
pressure can be ascertained by disconnecting the rod for weighing on
to lift or ease the valve and placing weights at that end until the valve
lifts, as then the weight or pressure can be easily computed; the
pressure cannot be increased without taking off two or more padlocks,
but the pressure can be diminished by taking off one padlock, the
pressure when steam is up can also be obtained by proceeding as before
described, and by adding the pressure indicated by guages or indicators,
and taking a mean or having a pipe in a convenient place, with couplings
to suit, a pressure gauge carried by the Board of Trade inspectors, and
then they could make use of their own guages in case they were of
opinion that the guages on boilers were not correct, but when steam is
down no guages will be required. A centre spindle on back of valve
passes through cover on top of casing for the bonnet to fit on and for
the purpose of casing the valve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Rochford in the Great Seal Patent Office on
the 2nd October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ROCHFORD, of Number Six, Cabra Parade, in the County of the City
of Dublin, Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of April, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Rochford, Her special licence
that I, the said John Rochford, my exccutors, administrators, 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 "A SPRING- Safety
VALVE FOB MARINE, LOCOMOTIVE, AND STATIONARY BOILERS," upon the con-
dition (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 bo 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 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:
A spring safety valve for marine, locomotive, and stationary boilers
constructed according to this Invention consists of a casing with a cover
secured by bolts and nuts, one or more of the bolts having a padlock,
so that the cover cannot be taken off without unlocking the padlock.
Inside the casing is a feather or spindle valve having a cylinder fitted
on the back of valve for the purpose of protecting the spring from the

page_text: escaping steam, and keeping the spring in proper position. If the
spring should break, the top of the cylinder would come into contact
with the under side of the nut in the cover, and thus prevent the valve
coming out of its seating. In the cover is a nut, into which screws a
piston and cylinder, and a head on top of cylinder for working the
piston to compress the spring contained in the cylinder on the top of
the valve, the head coming into contact with top of the nut in the cover
prevents the pressure being increased beyond that for which the valve
was allowed to carry. Liners are used between the head of the piston
and the top of the spiral spring, so that by taking out the liners the
pressure can be reduced, or should it be required to reduce the pressure
without taking off the cover it can be done by unlocking the padlock in
the key that passes through the bonnet and screwing back the piston;
the bonnet can be again put on and a narrower key used. The spiral
spring is confined in the cylinder on the back of the valve, and com-
pressed by the piston working in the cylinder and passing through the
cover. The easing gear consists of a lever having its fulcrum between
the valve spindle and the rod for weighing on to lift or ease the valve.
The joints are all bushed or lined with brass or other anti-corrosive
metal, and the pins are also made or lined with brass or other anti-
corrosive metal, so that should the valve be out of use for a lengthened
period the joints would not be rusted or corroded. The pressure can be
ascertained by disconnecting the rod for weighing on to lift or case the
valve, and placing weights at that end until the valve lifts, as then the
weights or pressure can be easily computed. The pressure cannot be
increased without taking off two or more padlocks, but the pressure can
be diminished by taking off one padlock; the pressure when steam is up
can also be obtained by proceeding as before described, and by adding
the pressure indicated by guages or indicators, and taking a mean or
having a pipe in a convenient place with couplings to suit a pressure
guage carried by the Board of Trade inspectors, and then they could
make use of their own guages in case they were of opinion that the
guages on boilers were not correct, but when steam is down no guages
will be required. A centre spindle on the back of the valve passes
through the cover on the top of the casing for the bonnet to fit on and
for the purpose of easing the valve.

page_text: Figure 1 is a sectional side elevation of a spring safety valve according
to this Invention fitted with easing lever and also with spare lever shown
in dotted lines. Figure 2 is an outside end view of same.
into practical effect, and for that purpose I have hereunto attached a
Sheet of Drawings illustrating a three-inch spring safety valve con-
structed according to this Invention, suitable for sixty pounds pressure
to the square inch. The Drawings are half size and are marked with
letters and figures of reference corresponding corresponding with those
in the following explanation:-
Figure 1 is a sectional side elevation of a spring safety valve according
to this Invention fitted with easing lever and also with spare lever shown
in dotted lines. Figure 2 is an outside end view of same.
Figure 3 is a sectional elevation of a portion of cylinder and springs
showing washer for dividing springs.
Figure 4 is a sectional elevation showing right and left handed springs
fitted in cylinder.
Upon reference it will be seen that the spring safety valve consists of
a casing or valve box A having a cover B secured by bolts and nuts, onc
or more of which bolts C is arranged to be secured by a padlock, so that
the cover B cannot be removed from the valve casing or box A without
unlocking the padlock. The cover B is fitted with a brass nut D screwed
into the brass bush E, which bush is screwed or otherwise attached to
the cover B. The brass nut D forms a guide to the valve spindle F.
Inside the valve casing or box A, is a feather or spindle valve G fitted
on to a suitable seat H. On the back of the valve G there is fitted or
attached a cylinder K for the purpose of protecting a spiral or other
spring L, which is fitted round the valve spindle F and inside the
cylinder K, and is thus protected from the action of the escaping steam.
The cylinder K takes on to the nut D, which nut forms a guide or piston
to the said cylinder. The cylinder K is left sufficient clearance from
the valve casing cover at I to allow for the lift of the valve. Between
the guide or piston D and the spring L there are fitted a series of
washers M serving to regulate and adjust the pressure on the spring.
The valve spindle F is fitted with a bonnet N, and is arranged with a
slot and key O, which key may be secured with a padlock at O. P is
an easing lever which takes on to the studs R on the bonnet N. The
easing lever P is carried by and has its fulcrum on the standard S..
T is a rod to easing gear; U is a spare lever for use if the spring L
breaks; V is a provision for a waste steam pipe; W, provision for a

page_text: boiler..
Referring to Figure 3, Y is an intermediate washer used when two or
more lengths of springs are applied.
Referring to Figure 4 it will be seen that the intermediate washer Y
may be used to connect right and left-handed springs.
Upon reference it will be seen that the spindle or feather valve G is
kept in position and weighted by the spiral spring L, which spring is
completely protected from the action of the escaping steam by the
cylinder K, which is screwed or otherwise attached to the valve G.
Should the spring break the cylinder K acts as a stop by coming
against the top of the valve casing, and thus prevents the valve lifting
out of its seat. The washers M serve as a means for regulating the
strength of the spring, and thereby the weight on the valve. The
easing lever P serves also for testing the pressure on the valve at any
time, as by placing weights on the lever the valve lifts and the pressure
can be easily computed. The pressure on the valve cannot be increased
or diminished without taking off the padlock at O', and tampering with
the washers M. The valve is kept perfectly secure by means of the
padlocks at C and O'. In case the spring L breaks down the spare
lover U can be brought into operation for keeping the valve down by
letting it bear, as shown in dotted lines, on the top of the valve spindle
at Z: The spare lever can be kept down by weighting or by a spring
balance.
In some instances it will be found expedient to keep the cylinder K
full or partially full of oil or other lubricating liquid, as the oil will
preserve the spring from rust or corrosion.
In some instances when the nut D is screwed back and the pressure
relieved to a certain extent a liner hoop may be put round the neck of
the nut, that is, between the nut and the cover B. The ends of the
liner hoop may have holes to take a padlock so arranged as to prevent
the nut being screwed down again. This arrangement would prevent
the necessity of taking off the cover and nut D and the levers, and still
enable the pressure to be reduced. An all-round collar may be sub-
stituted with advantage in lieu of the studs R on the bonnet N for the
easing gear, so that the valve can be turned round in the casing if
required.

page_text: Having now fully described and explained the nature and purposes
of this my Invention, and how the same may be carried into practical
effect, I wish it to be clearly understood that I do not limit myself to
the several proportions and relative dimensions of the various parts of
the spring safety valve as shown, as it will be readily seen that the same
may be considerably varied without departing from my Invention, but
what I claim as the Invention secured to me by Letters Patent as
aforesaid is, a spring safety valve for marine, locomotive, and stationary
boilers made and constructed substantially in the manner and for the
purposes as set forth and described in the beforegoing Specification and
Drawings.
In witness whereof, I, the said John Rochford, have hereunto
set my hand and seal, this Thirtieth day of September, in
the year of our Lord One thousand eight hundred and seventy-
three.
Witness,
FREDERICK JOHN CHEESBROugh,
of 15, Water Street,
Liverpool.
JOHN (L.s.) ROCHFORD.