IMPROVEMENTS IN AND RELATING TO FLUE TUBES FOR STEAM BOILERS
Year: 1881

page_text: LETTERS PATENT to John Addy Hopkinson and Joseph Hopkinson, both of
the Firm of J. Hopkinson & Co., of Huddersfield, in the County of York,
Engineers, for an Invention of "IMPROVEMENTS IN AND RELATING TO FLUE
TUBES FOR STEAM BOILERS."
PROVISIONAL SPECIFICATION left by the said John Addy Hopkinson and
Joseph Hopkinson at the Office of the Commissioners of Patents on the
14th January 1881.
JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of
J. Hopkinson & Co., of Huddersfield, in the County of York, Engineers.
"IMPROVEMENTS IN AND RELATING TO FLUE TUBES FOR STEAM BOILERS."
Our Invention relates to flue tubes for steam boilers, and is designed to facilitate
the securing of transverse water circulating pipes or tubes in corrugated flue tubes,
such as are described in the Specification of our former Letters Patent, dated
the 9th day of August, A.D. 1880, No. 3258, and other tubes for similar purposes.
In our said former Specification we have described corrugated flue tubes which
have plain or uncorrugated portions extending entirely or partially around them
in the direction of or parallel to the corrugations, and the said circulating tubes
are fixed in these plain or uncorrugated portions. But according to our present
Invention we provide for securing such transverse pipes or tubes in the corrugated
portions of such flues so that we are not compelled to provide our corrugated tubes
with any plain or uncorrugated portion for the reception of the water circulating
tubes, therefore we can furnish boilers with flues provided with water circulating
pipes and corrugated throughout their entire length; or we may fix such pipes.
in the corrugated portions of flues which have both corrugated and plain portions.
For the purpose of our said Invention we make in the corrugated flue tube or
corrugated portion of a flue tube holes of the proper diameter for the reception of
the said circulating pipes, and in making these holes we raise the metal around
them in such a manner as to form a.rim or collar. The transverse pipe is fitted
and rivetted, welded, or otherwise secured within this rim or collar.
This rim or

page_text: collar affords greater facility than has heretofore existed for welding the pipes in
the flue, as instead of having only the thickness of the metal of the flue at its
edge for welding, the entire interior surface of the collar, or a great portion of such
surface, is available for this purpose. The said pipes may be flush with the outer
edge of the collars, or may project beyond the said collars to any desired extent.
In some instances we secure the said pipes in the flue tube in the following
manner, that is to say:-The pipe is preferably made slightly taper (largest at its
upper end), and is placed in the flue with its upper edge projecting above the
upper collar and with its lower end not projecting down to the outer edge of the
lower collar. We place over the top and bottom collars bridges or cross-pieces,
and these bridges are united by a bolt passing through the said pipe, and by means
of a nut on the end of this bolt we draw the said pipe tightly and securely into
its collar. Or we may use either a taper or a parallel pipe, and secure the same
by the aid of rings in combination with the said bridges and bolt and nut.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Addy Hopkinson and Joseph Hopkinson in the Great Seal
Patent Office on the 29th June 1881.
JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of
J. Hopkinson and Co., of Huddersfield, in the County of York, Engineers.
"IMPROVEMENTS IN AND RELATING TO FLUE TUBES FOR STEAM BOILERS."
Our Invention relates to flue-tubes for steam-boilers, and is designed to facilitate
the securing of transverse water circulating pipes or tubes in corrugated flue-tubes,
such for example as are described in the Specification of our former Letters Patent,
dated the 9th day of August, A.D. 1880, No. 3258.
In our said former Specification we have described corrugated flues. or flue tubes
which have plain or uncorrugated portions extending entirely or partially around
them in the direction of or parallel to their corrugations, and the said circulating
pipes are fixed in these plain or uncorrugated portions. But according to our
present Invention we provide for securing the transverse pipes or tubes in the
corrugated portions of such flues, so that we are not compelled to provide our
corrugated tubes with any plain or uncorrugated portion for the reception of the
water circulating tubes, therefore we can furnish boilers with flues or flue-tubes
provided with water-circulating pipes, and corrugated throughout their entire
extent; or we may fix such pipes in the corrugated portions of flues, consisting of
alternate corrugated and plain portions.
Our Invention is illustrated in the accompanying Drawing, in which,-
Figure 1 is a plan or top view of a portion of a corrugated flue-tube.
Figure 2 is a side elevation of the same.
Figure 3 is a longitudinal section on the line x, x, and
Figure 4 is a transverse section on the line y, y.
Like letters indicate the same parts throughout the Drawing.
For the purpose of our said Invention, we make in the corrugated flue-tube a (or
corrugated portion of a flue tube) holes of the proper diameter for the reception of
the said circulating pipes b, and in making these holes we raise or bulge out the
metal around each of the same in such a manner as to form a rim or collar c at the
top and bottom, or at opposite sides of the flue-tube, as clearly shewn in Figures 3
and 4. Each transverse pipe b is made of the proper length to extend across the
flue a, and has its ends fitted within the said collars, as shewn in the last named
Figures, and each end is rivetted, welded, or otherwise secured within the'rim or
collar into which it is fitted. These rims or collars afford greater facility than has
heretofore existed for welding or attaching the pipes b in the flue, as instead of
having only the thickness of the metal of the flue around the hole for welding to
the pipe, we now have the entire interior surface of the collar or a great portion
of such surface available for this purpose. The said pipes b may be flush with the
outer edge of the collars c, or may project beyond the said collars to any desired
extent.
The making of the holes with the collars or rims surrounding the same is effected
subsequently to the corrugating of the said flue-tubes, and in practice we find it
convenient to use for this purpose a corrugated die or block for supporting the
flue-tube, while each hole with the collar around the same is formed by a punch or
mandril forced through the metal from the inside of the flue tube, a hole being
provided in the said block of the required diameter or size, to permit the passage of
the punch, and assist in giving the desired form to the said collar.
Having thus fully described our said Invention, we wish it understood that we
do not now claim the formation of collars or rims upon the plain or uncorrugated

page_text: portions of boiler flue tubes for the reception of water circulating pipes, this
manner of providing such tubes with circulating pipes being fully set forth in the
Specification of our said former Letters Patent; neither do we claim or limit
ourselves to any particular method of or means for forming such rims or collars in
the flue-tubes, or of securing the pipes in the said collars, but we claim,-
Providing or constructing a boiler flue or flue-tube with water circulating pipes
in the manner above described, that is to say, by inserting and securing the latter
within rims or collars raised or bulged out from the corrugations or corrugated
portions of the flue, without any plain or uncorrugated portion extending beyond
or outside of the said collars, as and for the purpose specified.
In witness whereof, I, the said John Addy Hopkinson, for myself and on
behalf of the said Joseph Hopkinson, have hereunto set my hand and seal,
this Fifteenth day of June, in the year of our Lord One thousand eight
hundred and eighty one.
Witness,
CARTER HOYLE, .
Cashier,
Huddersfield.
JOHN ADDY HOPKINSON. (L.S.)