IMPROVEMENTS IN APPLIANCES FOR STOPPING OR PLUGGING THE ENDS OF BOILER TUBES
Year: 1882

page_text: "
LETTERS PATENT to Duncan MoMillan of Govan in the County of Lanark,
North Britain for an invention of IMPROVEMENTS IN APPLIANCES FOR
STOPPING OR PLUGGING THE ENDS OF BOILER TUBES Communicated to
him from abroad by Neil McMillan presently residing at Marseilles in the
Republic of France
PROVISIONAL SPECIFICATION left by the said Duncan McMillan at the
Office of the Commissioners of Patents on the 8th June 1882
DUNCAN MCMILLAN, of Govan, in the County of Lanark, North-Britain,
"IMPROVEMENTS IN APPLIANCES FOR STOPPING OR PLUGGING THE ENDS OF BOILER
TUBES," (a communication to me from abroad by Neil McMillan presently residing
at Marseilles in the Republic of France),
This Invention relates to improvements in appliances to be used for stopping or
plugging the ends of marine or other boiler tubes which have become leaky or are
otherwise damaged, and which cannot conveniently be removed and replaced during
a voyage, or without loss of time.
The improved stopping appliances comprise two short tubes or rings of copper,
which are of slightly smaller diameter than the boiler tube to be closed, and are
fitted, one within each end of it, by preference being made to project a little outside
the boiler tube plate. These short copper tubes or rings are fitted on and held in
position by shoulders on strong metal washers or annular discs placed inside the
boiler tube, and which are connected to or made to bear on their inner sides,
against the ends of a central stay tube. Into the open outer end of each copper
tube is fitted a metal conical stopper or tapered plug bearing on the inside of the
copper tubes, and through these stoppers is passed a long bolt, also passing centrally
through the stay tube and washers within the boiler tube. One end of this central
bolt is formed with a gripping head which may be counter-sunk in one of the plugs,
and at the, other end the bolt is screwed and fitted with a screwed nut outside the
plug or stopper at that end.
.
To close the boiler tube, the screw nut is turned by a spanner, to draw together
the metal plugs against which the head of the bolt and the nut bear, and by this
means the conical plugs expand the copper tubes until they bear against the outer
ends of the boiler tube, and are firmly gripped between it and the plugs.
To prevent electro-chemical action which might result from contact of the
copper tubes with the iron boiler tube, the copper tubes are tinned or coated
with a similar metal or alloy, which will also withstand the action of the fire
gases.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Duncan McMillan in the Great Seal Patent Office on the
7th December 1882.
DUNCAN MOMILLAN of Govan in the County of Lanark, North-Britain,
"IMPROVEMENTS IN APPLIANCES FOR STOPPING OR PLUGGING THE ENDS OF BOILER
TUBES" (the same has been communicated to me from abroad by Neil McMillan
presently residing at Marseilles in the Republic of France
This Invention relates to improvements in appliances to be used for stopping
or plugging the ends of marine or other boiler tubes which have become leaky or
are otherwise damaged, and which cannot conveniently be removed and replaced
during a voyage or without loss of time.
The Invention is illustrated by the accompanying Drawings in which figure 1
is a longitudinal section of a marine boiler tube showing, the improved stopper
fitted inside, ready for plugging the tube which may be supposed to have burst,
while figure 2 is a similar view, but showing the stopper screwed up and effectually
stopping or plugging the ends of the boiler tube. The tube A is shown fitted in
the tube plate B of the boiler, but the boiler is not otherwise shown. The tube
and stopper are also for convenience shown broken.
The improved stopping appliances comprise two short tubes or rings of copper C,
which are of slightly smaller diameter than the boiler tube A to be closed, and are
fitted, one within each end of it, by preference being made to project a little
outside the boiler tube plate B.
These short copper tubes or rings C are fitted on and held in position by
shoulders & in strong metal washers or annular discs D placed inside the boiler
tube A, and which are connected to or made to bear by shoulders d' on their inner
sides, against the ends of a central stay tube E. Into the open outer end of each
copper tube C is fitted a conical stopper or tapered plug F of metal bearing on the
inside of the copper tubes, and through these stoppers F is passed a long bolt G
also passing, centrally through the stay tube E and washers D within the boiler
tube A. One end of this central bolt G is formed with a gripping head G' which,
though not so shown, may be countersunk in one of the plugs F, and at the other
end the bolt is screwed and fitted with a screwed nut G outside the plug or
stopper Fat that end, or both ends of the bolt may be screwed and fitted with
nuts. To close the boiler tube A, the screw nut G2 is turned by a spanner to screw
it on to the bolt G and draw together the metal plugs F against which the head G¹
of the bolt G and the nut G2 bear, and by this means the conical plugs, press
against and expand the copper tubes C, until they bear hard against the outer ends
of the boiler tube A and are firmly gripped between it and the plugs F.
To prevent electro-chemical action which might result from contact of the
copper tubes C with the iron boiler tube A, the copper tubes C are tinned or
coated with a metal or alloy similar to tin, which will also withstand the action
of the fire gases.
Having thus described the said Invention, and the manner of performing the
same, I have to state that what I claim is :-
First. As means for stopping or plugging boiler tubes, the construction of
appliances in which are combined the copper rings or tubes C. C., washers D, D,
stay tube E, metal plugs F. F, and screw bolt G, substantially as herein Described
and illustrated by the accompanying Drawings.

page_text: Second. The combining with tube stopping appliances of the kind herein
described, of rings of copper (C) coated or covered with tin or similar metal or
alloy, substantially as and for the purpose herein set forth.
In Witness Whereof, I the said Duncan MeMellan, have hereunto set my hand
and seal, this Sixth day of December, in the year of our Lord One thousand
eight hundred and eighty-two.
DUNCAN MOMILLAN (L.S.)