IMPROVEMENTS IN THE STAYING OF FIRE-BOXES AND OTHER PARTS OF BOILERS, AND IN THE MANUFACTURE OF PLATES THEREFOR
Year: 1878

page_text: LETTERS PATENT to John Stephenson, of No. 29, East Mount Road, in the
City of York, Engineer, for the Invention of "IMPROVEMENTS IN THE STAYING
OF FIRE-BOXES AND OTHER PARTS OF BOILERS, AND IN THE MANUFACTURE
OF PLATES THEREFOR."
"
Sealed the 10th May 1878, and dated the 14th March 1878.
PROVISIONAL SPECIFICATION left by the said John Stephenson at the Office
of the Commissioners of Patents on the 14th March 1878.
JOHN STEPHENSON, of No. 29, East Mount Road, in the City of York, Engineer.
"IMPROVEMENTS IN THE STAYING OF FIRE-BOXES AND OTHER PARTS OF BOILERS,
AND IN THE MANUFACTURE OF PLATES THEREFOR."
The plates of a boiler exposed to the action of fire and hot products of combustion,
particularly those which form the sides of the fire-box, are usually supported by
stay bolts passed or screwed through them and secured to the outer shell or to other
plates, separated from the former by a water or steam space. As the plate and the
bead of the stay bolt become corroded, scaled, or burnt, the hold of the stay on the
plate and the plate itself are so much weakened that the latter frequently gives way
and serious accidents occur from this cause.
The object of my Invention is to strenghen such plates in thoso parts through
which the stay bolts pass to give the stay bolts a better hold therein and to protect
the stays as well as the strengthened portions of the plates from the destructive
action of the heat. For this purpose I subject those parts of the plates through
which stay bolts are to pass to a squeezing action produced either by pressure or
blows between blunt punches and hollow dies so that the metal of the plate is at
each stay place hollowed in on the one side and made to project as a boss on the
other side.
In some cases I subject the stay bosses produced as above described to a further
'squeezing action between punches and dies so as to thin the middle of the boss and
swell it out laterally.

page_text: The embossing may obviously be effected by passing the plates between rollers
having suitable hollows and projections; also when the metal will permit, the
required bosses may be formed by casting them on the plates, soldering or welding
them thereon. Through each boss I make a hole, and cut a screw thread in it for
the reception of the stay bolt, the head of which appears on the one side of the plate 5
that is to be exposed to the action of the heat, whilst its screw thread extends
throughout the whole depth of the boss that projects on the other side.
The hole in the boss may be countersunk to receive the partly coned head of the
stay bolt, which can thus be partly sunk into the body of the embossed plate. Plates
thus prepared and stayed may be very much thinned down by the action of the 1
heat, and the heads of the stay bolts may be quite burnt away and yet the stays
retain a good hold by the depth of screw thread still remaining in the bosses which
project on the side of the plate that is not exposed to the destructive action.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Stephenson in the Great Seal Patent Office on the 31st August 1
1878.
JOHN STEPHENSON, of No. 29, East Mount Road, in the City of York,
Engineer. "IMPROVEMENTS IN THE STAYING OF FIRE-BOXES AND OTHER PARTS
OF BOILERS, AND IN THE MANUFACTURE OF PLATES THEREFOR."
The plates of a boiler exposed to the action of fire and hot products of combustion, 2
particularly those which form the sides of the fire-box, are usually supported by
stay bolts passed or screwed through them and secured to the outer shell or to other
plates, separated from the former by a water or steam space. As the plate aud the
head of the stay bolt become corroded, scaled, or burnt, the hold of the stay on the
plate and the plate itself are so much weakened that the latter frequently gives way 2
and serious accidents occur from this cause.
The object of my Invention is to strengthen such plates in those parts through
which the stay bolts pass to give the stay bolts a better hold therein and to protect
the stays as well as the strengthened portions of the plates from the destructive
action of the heat. For this purpose I subject those parts of the plates through a
which stay bolts are to pass to a squeezing action produced either by pressure or
blows between blunt punches and hollow dies, so that the metal of the plate is at
each stay place hollowed in on the one side and made to project as a boss on the
other side.
In some cases I subject the stay bosses, produced as above described, to a farther:
squeezing action between punches and dies so as to thin the middle of the boss and
swell it out laterally.
The embossing may obviously be effected by passing the plates between rollers
having suitable hollows and projections; also, when the metal will permit, the
required bosses may be formed by casting them on the plates, soldering or welding
them thereon. Through each boss I make a hole, and cut a screw thread in it for

page_text: the reception of the stay bolt, the head of which appears on the one side of the
plate that is to be exposed to the action of the heat, whilst its screw thread extends
throughout the whole depth of the boss that projects on the other side.
The hole in the boss may be countersunk to receive the partly coned head of the
stay bolt, which can thus be partly sunk into the body of the embossed plate.
Plates thus prepared and stayed inay be very much thinned down by the action of
the heat, and the heads of the stay bolts may be quite burnt away and yet the stays
retain a good hold by the depth of screw thread still remaining in the bosses which
project on the side of the plate that is not exposed to the destructive action.
Fig. 1 shews a section of part of a plate hollowed on the one side and bossed out
on the other to receive a stay bolt, as shewn in Fig. 2. For this purpose a hole is
drilled and tapped through the centre of the embossed part of the plate, and the
stay bolt is screwed in and has its head rivetted over.
Fig. 3 shews a section of part of a plate which has been subjected to the farther
embossing action by forcing a slightly tapered punch into the middle of the
embossed part so as to thin the metal in the centre and spread it out laterally.
Fig. 4 shews the same plate with its stay bolt-headed."
For producing the embossing shewn in Fig. 1 the plate is pressed or hammered
between a rounded punch applied on the one side and a hollowed matrix on the
other side, and after the plate "has thus been embossed it may receive the farther
embossing shewn in Fig. 3 by subjecting it to pressure or blows between the taper
punch applied on the one side, and a matrix shaped to suit the desired boss on the
other side.
The punches and matrix hollows for thus embossing plates may be formed on the
peripheries of rollers, between which the plates are made to pass under suitable
pressure.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim embossing boiler plates at the points through which
stay bolts pass, substantially as and for the purposes herein set forth.
.
In witness whereof, I, the said John Stephenson, have hereunto set my hand
and seal, this Twenty-ninth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.