and other Derangements in Steam Boilers.
Year: 1885

page_text: and other Derangements in Steam Boilers.
I JOHN CROSBY HARGREAVES of Moorville Place, Beeston Hill, Leeds in the
County of York Engineer do hereby declare the nature of said invention for
"IMPROVEMENTS IN APPARATUS FOR THE PREVENTION OF EXPLOSIONS AND OTHER
DERANGEMENTS IN STEAM BOILERS to be as follows:-
"
The invention relates to apparatus for preventing boiler explosions arising from
excessive steam pressure and other derangements which are liable to occur when
the water in the boiler is above or below the high or low water line.
My apparatus is applicable in connection with dead weight safety valves used
for the above purposes and its object is to increase the efficiency or render more
safe the use of such valves; not only does it prevent tampering therewith but by
its application the correct working of the valve may be tested at any moment.
The dead-weight safety valve is placed in the roof of the boiler and enclosed
within the steam chest as in the invention for which Letters Patent were granted
to Thomas Constantine Fawcett and myself dated 6th February 1883 N° 654.
But I find in practice that these dead-weight valves are liable to stick and it is
necessary that the attendant should be ready at any moment to lift such valve to
see whether it is in working order, at the same time it is very important that such
attendant or others should not be able readily, to get at such valve, thus preventing
over weighting the same and other mischief.
In order to lift the valve I apply a link which is attached at its lower end to the
upper portion of the valve, so that by the aid of a vertical rod it may be drawn
upwards so as to lift the valve off its seat, but also arranged that no weight applied
on such vertical rod can be transmitted through the link onto the valve.
The vertical lifting rod may be actuated by screw and nut, or lever attachment.
In the side of the steam chest which encloses the dead-weight valve I provide a
cock which can be opened when the valve is being tested, a hand hole may also be
provided in the side for the purpose of attaching the link to the safety valve, but
this hand hole is covered by a lid which is bolted or screwed to the steam chest.
Dated this 24th day of February 1885
J. W. HARDING,
For the Applicant.

page_text: vertical rod o the link m may be drawn upwards thus lifting the valve f off its
seat, but in this arrangement no weight applied on the vertical rod o can be
transferred through the link m onto the valve f
The lifting rod o may be arranged to operate through the medium of the screw
thereon, engaging into a nut, the required motion being imparted thereto by hand
wheel p, or the rod may be lifted and the valve raised by an ordinary lever
arrangement mounted on the chest and attached thereto.
In the side of the steam chest d I provide a cock q when the valve is being
tested.
A hand holer may also be provided in the side of the steam chest for the purpose
of attaching the link m to the safety valve f, but this hand hole r is covered with
a lid s which is bolted or screwed to the steam chest d.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1st The application of link m and parts connected there with for lifting dead
weight safety valves, such valve being enclosed in the steam chest d, all arranged
substantially as and for purposes herein set forth.
2nd The employment of apparatus for lifting dead weight safety valves in
combination with apparatus for prevention of explosions and other derangements
in steam boilers described in the Specification of Patent No 654 dated 6th February
1883 and with other similar apparatus, substantially as herein set forth.