Improvements in Stoppers for Boiler Tubes.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Stoppers for Boiler Tubes.
I, JOHN HOWIE POLLARD, a subject of Great Britain, residing at No. 187
West 134th Street, in the City, County and State of New York, United States
of America, Machinist, 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:-
The object of my invention is to stop up leaking or bursted boiler tubes by
utilizing the heat of the boiler to set in operation a novel plugging device without
drawing the fires or interrupting the use of the boiler. To more particularly
describe my novel plugging device, I will refer to the accompanying drawings.
Figure 1, shows a vertical longitudinal section of a boiler tube k, with the
plugging device inserted therein ready for operation, one end of the plugging device
being shown in similar section, the other end in side elevation. The boiler tube and
stopper are shown broken, the parts omitted being the continuation of the boiler
tube and rod a, of the stopper.
Figure 2 shows the same section of the tube and plugging device as Figure 1,
and also a similar section of the other end of the plugging device, and the whole
plugging device in operation stopping up the tube.
Figure 3 is a detailed view in cross section of a part of the plugging device shown
at g, Figures 1 and 2;
Figure 4 is another detailed view in similar section of the same part;
Figure 5 is a detailed view in section showing a modification in construction of
the like parts f, f, in Figures 1 and 2 ;
Figure 6 is a vertical longitudinal section showing a modification in the parts of
the plugging device shown in Figure 1.
Letter a, represents a forged metal rod corresponding in length to the boiler
tube. The similar collars 6, b, forged upon the rod a, support the strong spiral
springs c, c, which bear outwardly on the loose circular washers d, d, facing which
are the circular washers e, e¹, bored with screw thread to fit respectively the screw
thread turned on the ends of the forged rod a. The opposing washers, d and e',
embrace and support an annular metal band f, and towards their centres are made
with bevelled projections upon which rests the metal coil g. The washers, d and e,
at the other end of the rod a, are similarly designed to support a like metal band f,
and like coil g. The washer e¹, is flanged at i, to prevent the stopper from entering
too far within the tube k.
The metal coil g, Figures 1 and 2, may be formed by coiling a strip of brass or
other suitable metal of the desired width and length, binding the coil temporarily
with wire, w, Figure 3, and dipping the coil first into muriatic acid and then into
molten fusible metal. After cooling and removing the tying wire, the coil will
of sweating
remain fastened by the quantity of fusible metal taken up in the process
just described. The coil is then ready to be placed between the washers at each
end of the stopper. The annular metal bands f, f, Figure 1, are grcoved on
the inner side in V-shape as at 1, Figures 1 and 2, to facilitate an outward
expansion of the metal band under pressure as shown in Figure 2; another form of
groove, shown at 1, Figure 5, may also be used to advantage. I prefer to make the
expanding metal of lead, but do not limit myself to the use of metal, and any other
suitable expansible material may be used for this purpose. The washers, d, d, e, e¹,
and the metal bands, f, f, are made of such size as to allow the stopper to freely
enter the tube until arrested by the flange i, on the washer e¹. The pairs of
washers and enclosed metal bands are arranged apart from each other on the rod,

page_text: in order to include as much as possible of the boiler tube. The springs, c, c, are
compressed by screwing the washers e, e', on the rod a, against the metal coil g, by
the nut ends h, h, and locked by the jam nuts g, g.
The operation of my invention is as follows: The stopper constructed as
described is inserted within the boiler tube. The heat of the boiler tube
immediately liquifies the fusible metal fastening of the coil g, which, being
loosened, expands as shown in Figures 2 and 4. The expansion of the coils g,
frees the washers d, d, and the springs c, c, which compress the bands, ff,
expanding them at 1, Figure 2, outwardly against the side of the boiler tube, thus
completely closing the tube at both ends. The bands, f, are preferably made
of a width slightly less than the space between the opposing faces of the washers
when held in check by the fusible coil g, to enable the springs, c, c, to gain
momentum on being released. To remove the stopper, it is only necessary to
unscrew the washer e, after loosening the lock nut g, and while holding the squared
end of the rod at a. Instead of the band f, and the fusible coil g, shown in
Figures 1 and 2, two U-shaped lead pieces f,f, Figure 6, with their opposing faces
bevelled as at 1, may be used, the loose washer d, being formed with a projecting
bearing to fit into a corresponding space, provided in the washer e, or e¹. This
space being filled with fusible metal m, after the spring has been compressed, the
loose washer is held back against the spring. Within the boiler tube, the heat as
before liquifies the fusible metal, which escapes between the rod a, and the loose
washer d, and the lead pieces f, f, thereupon compressed and expanded, close up the
tube, as before described. To permit the escape of the fusible metal in the form
of construction shown in Figure 6, and to avail of the steam in the boiler tube to
aid in expanding the lead band or picces, the borings of the loose washers d, d, are
made larger than the circumference of the rod a.
Beside securing immediate action in plugging the tube, I am enabled by my
improvement to dispense with the use of pressure or force against the boiler sheet,
and do not require a large escape of steam in the boiler tube to furnish the
necessary pressure to expand the plugging band.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare what I claim is :
First. In a boiler tube stopper the combination of an expansible band with
compressing washers, a fusible check and a pressure spring, substantially as
described.
Second. In a boiler tube stopper the combination of an expansible band with
expanding mechanism, and a fusible check, substantially as described.
Third. A boiler tube stopper, consisting of a rod carrying at each end a pressure
spring, compressing washers, a fusible check, and an expansible band, constructed
and arranged substantially as described.
Fourth. In a boiler tube stopper the combination of the pressure spring, the
compressing washers, the fusible metal coil, and the expansible band, constructed
and arranged substantially as described.
Fifth. In a boiler tube stopper the combination of the pressure spring, the
compressing washers, the fusible metal, and the expansible band, constructed and
arranged substantially as described.
Dated this 28th day of November 1893.
ALLISON BROS.,
Agents for the Applicant.