Improvements relating to the Manufacture of Pipes or Tubes and to Apparatus therefor.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Pipes or Tubes and to
Apparatus therefor.
I, CARL GUSTAF LARSON, of Sandviken, in the Kingdom of Sweden,
Engineer, 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 :-
Tubes with longitudinal ribs flanges or grooves are much used, partly because
they possess great superficial surface and partly owing to their great stiffness
against bending compared with their diameter.
Such tubes have hitherto been produced by drawing or casting. When the tube
however is of a large diameter, drawing will hardly do excepting when the tube
wall itself is made undulating and when the said wall is comparatively thin. A
tube with free standing flanges on the cylindrical tube wall may certainly be
produced by casting but such tubes can not be used as boiler tubes and such like.
For the latter purpose particularly, tubes with inner flanges are much used, and it
is therefore the manufacture of such tubes and arrangement therefore which
constitute the object of this invention.
In the accompanying drawing
Figure 1 is a cross section of a tube provided with inside flanges.
Figure
2 is a similar view provided with inside as well as outside flanges.
Figure 3 is a section of the mandrel.
Figure 4 is an end view thereof, and
Figure 5 shows the application of the mandrel to the manufacture of tubes.
The flanges a extend radially from the cylindrical tube wall and are somewhat
wedge-shaped in cross section. The tube is produced by rolling upon a mandrel
and it is the shape of the latter which produces the inner flanges while the outer
flanges are formed by grooves in the roller. The mandrel is represented in
Figures 3 and 4. The same is somewhat conical and grooved longitudinally. The
grooves b, which form the flanges in the tube when rolled with. the material from
the small to the large end of the mandrel, are wider at the small end of the
mandrel, but contract towards the big end of the mandrel so that they have a
cross section equal to the desired flange. The mandrel is retained in its place
between the rollers Figure 5 in the usual way by means of a bar e which is
introduced into the hole e of the mandrel. When the tube is provided with inside
flanges in the manner described it may also at the same time be provided with
outside flanges, so as to present the appearance shown in Figure 2. This is effected
by providing the rollers, as when manufacturing rolled objects, with grooves, which
when rolling the tube upon the mandrel, produced the outer flanges.
In the above description of the method-mention-has-only_been made of flanges,
but it is evident that the tubes may be provided with grooves in the same way, by
which is meant the interspaces between the flanges, which may be thicker than those
shown in Figure 1 and which grooves are produced by wedge-shaped ridges extending
in the longitudinal direction of the mandrel, which ridges are separated by the
aforesaid grooves in the mandrel. A mandrel with grooves or ridges having
parallel sides in the longitudinal direction may also be used, but the mandrel
represented in the drawing is preferable.
It is moreover obvious, that the grooves or ridges in the mandrel may be so few
in number and therefore the interspaces between them so great that the material
between them can scarcely be called ridges nor the interspaces between the flanges
grooves, in short that grooves and ridges may not necessarily be thought to exist
imultaneously

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, 1 declare that what
I claim is
1. A method of, producing tubes with inner ribs, flanges or grooves, consisting in
rolling the tube material upon a mandrel having longitudinal grooves or ridges
corresponding to the desired flanges or grooves in the pipe.
2. A mandrel for rolling tubes with inner ribs flanges or grooves in the manner
specified in Claim 1; characterized by longitudinal grooves or ridges corresponding
to the said flanges, or grooves in the tube.
3. In the mandrel above described, the arrangement, in which the grooves are
wider at the small end of the somewhat conical mandrel and contract towards the
big end thereof to the desired extent to impart the necessary shape to the flanges
in the tube, or in which the ridges are wedge-shaped in the longitudinal direction
of the mandrel, tapering towards the small end.
Dated this 1st day of April 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.