Improvements in "Fusible Plugs" for Steam Boilers.
Year: 1891

page_text: Date of Application, 22nd Apr., 1891
Complete Specification Left, 21st Jan., 1892-Accepted, 27th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in "Fusible Plugs" for Steam Boilers.
1 SIDNEY MOORHOUSE of Victoria Works Stalybridge in the County of
Lancaster Engineer do hereby declare the nature of this invention to be as
follows:-
This invention relates to what are known as "fusible plugs" and applied to
steam boilers for the purpose of preventing explosion of the same in the event of
the water becoming too low, and especially to that class consisting of a hollow
brass or other metal plug provided with a disc of fusible metal.
The objects of the invention are to prevent the fusible disc from yielding to high
pressure and thus becoming leaky, and also to keep the same always in an efficient
state.
According to my invention I cast the hollow body of the brass or other metal
plug with a grating or perforated bed extending across the upper part, the face of
the grating or bed being recessed about half an inch below the face of the plug.
In this recess I place the fusible disc resting upon the grating or perforated bed
and closing the openings or perforations of the same.
Above this disc in the same recess I place a corresponding loose metal grating
or perforated plate the upper side of which is provided in the centre with a raised
stud or pap:
Over this top grating I place a thin dished metal cover provided in the centre
with a hole to allow it to pass over the stud or pap and with openings round the
edge.
The body of the plug is formed with two ears or projections at opposite sides
in which are fitted vertical slotted lugs; a taper metal key is driven horizontally
through these slots, and by pressing against the top of the stud or pap will hold the
loose grating or perforated plate firmly down upon the fusible disc, which latter
will thus be held quite securely between the two gratings, and hence it is not only
firmly supported so as to resist high pressure, but also a perfectly secure joint is
made and all leakage prevented.
The metal cover will prevent the "silting-up "of the openings or perforations
of the upper metal grating with dirt or sediment from the water, and thus the
fusible disc will always be kept in an effective condition.
Dated this 21st day of April 1891.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in "Fusible Plugs" for Steam Boilers.
I SIDNEY MOORHOUSE of Victoria Works Stalybridge in the County of
Lancaster Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :—
This invention relates to what are known as "fusible plugs" and applied to
steam boilers for the purpose of preventing explosion of the same in the event of
the water becoming too low, and especially to that class consisting of a hollow
brass or other metal plug provided with a disc of fusible metal.
The objects of the invention are to prevent the fusible disc from yielding to high
•

page_text: pressure and thus becoming leaky, and also to keep the same always in an efficient
state.
In order that my invention may be clearly understood I have annexed hereunto
a sheet of drawings and have marked the same with figures and letters of reference
corresponding with those in following description thereof.
Fig. 1 is a transverse section through the centre of one of my improved fusible
plugs.
Fig. 2 is an elevation of the same turned, one quarter of a revolution, or at right
angles to Fig. 1.
Fig. 3 is a plan view of the body a of the plug, detached, and
Fig. 4 a plan view of the grating or plate d hereafter referred to.
According to my invention I cast the hollow body a of the brass or other metal
plug with a grating or perforated bed 6 extending across the upper part, the face
of the grating or bed being recessed about half an inch below the face of the plug
as seen on Figs. 1 and 2.
In this recess I place the fusible disc c resting upon the grating or perforated
bed b and closing the openings or perforations of the same.
Above this disc in the same recess I place a corresponding loose metal grating or
perforated plate & the upper side of which is provided in the centre with a raised
stud or pap
a.
Over this top grating d I place a thin dished metal cover e provided in the centre
with a hole to allow it to pass over the stud or pap and with openings e¹ round the
edge as seen on Fig. 2.
The body of the plug a is formed with two ears or projections fat opposite
sides in which are fitted vertical slotted lugs g; a taper metal key is driven
horizontally through these slots and by pressing against the top of the stud or
pap d' will hold the loose grating or perforated plate & firmly down upon the
fusible disc, which latter will thus be held quite securely between the two
gratings b and d and hence it is not only firmly supported so as to resist high
pressure but also a perfectly secure joint is made and all leakage prevented.
The metal cover e will prevent the "silting-up" of the openings or perforations
of the upper metal grating d with dirt or sediment from the water, and thus the
fusible disc c will always be kept in an effective condition.
In some cases this cover e may be made of thin fusible metal without the
openings e (as seen on Fig. 1), thereby more effectually preventing the silting up
of the said perforated plate or grating 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 :-
The improvements in fusible plugs consisting principally in the combination of
a fusible metal disc with a gridded or perforated bed and a corresponding plate of
hard metal placed one above and one below the same substantially as and for the
purposes hereinbefore described and as illustrated by the drawings annexed.
Dated this 20th day of January 1892.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.