IMPROVE- MENTS IN SHEET METAL PIPES OR TUBES
Year: 1877

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, for the Invention of "IMPROVE-
MENTS IN SHEET METAL PIPES OR TUBES." A. communication from abroad
by Harvey Klapp Flagler, of Boston, Massachusetts, United States of
America.
Sealed the 28th August 1877, and dated the 16th July 1877.
COMPLETE SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 16th July 1877.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN SHEET METAL PIPES OR
TUBES." A. communication from abroad by Harvey Klapp Flagler, of Boston,
Massachusetts, United States of America.
This Invention relates to sheet metal pipes formed by winding the strip spirally
around a mandrel, and the said Invention consists in uniting the edges of the strip
and re-enforcing the seam or joint so formed by means of a separate and indepen-
dent strip of metal clinched down on the outside of the same in such a manner as
to hold the edges of the strip firmly together, the liability to separation of the
edges and the loosening and opening of the joint incident to this class of pipes
as heretofore constructed being thereby avoided.
The manner in which the said Invention may be most advantageously carried
into practice is illustrated in the accompanying Drawing, which I will now proceed
to describe.
Figure 1 is a perspective view of a spirally-wound sheet-metal pipe constructed
in accordance with this Invention.
Figure 2 is a perspective view illustrating the manner in which the said pipe is
formed.
Figure 3 is a transverse section representing the seam or joint of the said pipe
finished.
Figure 4 is a section drawn to an enlarged scale representing the seam or joint
previous to its being flattened down or finished.

page_text: Figure 5 represents the strip of sheet metal of the desired width, from which my
improved pipe is formed.
Figure 6 represents the narrow strip of sheet metal employed in re-enforcing the
seam of the said pipe.
'
A is a flat strip of sheet metal of the required width, and a is a narrow strip of
metal, both of which, as they are fed through a suitable machine, are wound
spirally around a mandrel or former; during this operation the edges of the strip A
are turned up and the edges of the strip a turned down, as seen in Figure 2. Then
the turned edges of the strip a, Figure 6, are directed against and caught over
the turned edges of the strip A simultaneously with their being made to abut
against each other, the parts being then in the position shewn in Figure 4.
Pressure is now applied by any suitable means to the sides of the turned down
edges of the narrow strip a, to force them toward and under the turned-up edges of
the wide strip A. Then the joint or seam is completed, as seen in Figure 3, by
flattening it down by a pressure roll or other means, the inside of the joint being
at the same time smoothly finished so as to offer no obstruction.
The above described joint imparts stiffness and rigidity to the pipe (which can
consequently be made of thinner metal than heretofore), for the reason that the
edges abut squarely against each other, and are held firmly and immovably together
by the re-enforcing strip a.
A sheet-metal pipe constructed in accordance with this Invention is particularly
applicable for stove pipes, pipes for conducting air and liquids, speaking tubes,
ventilator pipes, and the like, but will be found equally useful for many other pur-
poses; and the pipe may be made ornamental if desired by forming it of different
kinds of metal of the same or of different widths, or of a strip of one metal with a
re-enforcing strip of another metal.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
A spirally wound sheet-metal pipe in which the seam or joint is re-enforced by a
strip of metal clinched down thereon, as above set forth and for the purposes
specified.
Also, a spirally wound sheet-metal pipe constructed with a joint formed by
turning and abutting the edges of the metal and uniting or locking them together
by means of a re-enforcing strip, as above set forth and for the purposes specified.
In witness whereof, I, the said William Robert Lake, have hereunto set niy
hand and seal, this Sixteenth day of July, in the year of our Lord One
thousand eight hundred and seventy-seven.
WM RORT LAKE