Improvements in the Manufacture of Pipe or Tube Bends.
Year: 1892

page_text: Date of Application, 27th June, 1892
Complete Specification Left. 26th Apr., 1893-Accepted, 27th May, 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Pipe or Tube Bends.
I, FREDERICK JOSIAH CLINCH-JONES of 61, Goldington Road, Bedford,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved method of making pipes or tubes of sheet
copper or other metal but more particularly bends intended to withstand high
internal pressures such as copper bends used for marine purposes, and it consists in
coiling spirally upon a revolving mandrel a broad main strip of rolled sheet metal
with outwardly flanged edges and coiling upon the flanges of the main strip a
narrow capping strip with inwardly flanged edges, the flanges of both strips having
been bent slightly beyond the perpendicular to the plane of the strip, the diverging
flanges of the main strip being embraced by the converging flanges of the
capping strip.
The act of coiling tends somewhat to flatten down the flanges of both strips,
such flattening being completed by external pressure applied to the capping
strip by a roller swage or hammer simultaneously with, or subsequently to the
coiling.
By this means the flanges of the capping strip are caused to securely interlock
with the flanges of the main strip and to make a tight joint therewith able to
withstand the highest pressures.
In making a bend the main strip would be of varying width the edges being of
oppositely sinuous form or one edge being straight and the other sinuous so that
the breadth of the strip would be everywhere so proportioned that a bend of the
desired curvature will be produced.
Instead of using a separate cap strip, but one strip may be used, the cap portion
being formed on one edge thereof, by folding it on itself and flanging the edge so
as to adapt it to embrace and interlock with the oppositely flanged other edge of
the adjacent coil.
Dated this 27th day of June 1902
F. J. CLINCH-JONES,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Pipe or Tube Bends.
I, FREDERICK JOSIAH CLINCH-JONES, of 61, Goldington Road, Bedford,
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:-
My invention relates to a new method of making pipe or tube bends of sheet
metal and more particularly steam pipe bends of copper intended to withstand high
internal pressures, and it consists in flanging the sinuous edges of a strip of sheet
metal and coiling the strip spirally in such manner and under such conditions that
the flanged edges of adjacent convolutions shall be caused to engage with one
another (directly or through the medium of a capping strip) and be simultaneously
flattened down, so as to securely interlock and make a folded lap-joint capable of
withstanding very high pressures. The strip to be spirally coiled is of varying
width, the edges being of sinuous form oppositely curved the one to the other, the
Paine 8.11

page_text: variation in breadth of the strip depending on the intended diameter and radius of
curvature of the bend.
Reference is to be had to the accompanying drawings, forming part of this
Specification, which shew the various stages in the operation of making a
pipe bend.
Figure 1 represents the strip of sinuous form.
Figure 2 shews the preliminary operation of flanging the edges of the strip.
Figure 3 shews the intermediate operation by which the partially-formed flanges
are brought to a position at right angles to the plane of the strip and the metal
within the flanges channelled.
Figure 4 shews the final flanging operation, by which the flanges are carried
past the perpendicular to the plane of the strip, so as to prepare them for being
finally closed down by the pressure rollers after the oppositely-flanged edges have
been interlocked in the act of coiling the strip.
Figure 5 is an elevation of a machine for making the bend, shewing the closing
together, by pressure rollers, of the interlocked flanged edges of the strip.
Figure 6 is a perspective view of the same operation, shewing the feeding-in of
the strip and the interlocking of the edge of the straight portion with that of the
already spirally-coiled portion.
Figure 7 is a section, on a larger scale, of the joint and pressure rollers.
Figures 8 and 9 illustrate the method of uniting the edges of the coiled strip by
means of a capping strip.
The same letters of reference indicate the same parts in all the figures.
A, Figure 1, is a strip of sheet metal of varying width, the edges being of
sinuous form and oppositely-curved, the centres from which the curves are struck
not being directly opposite one another, or on the same transverse lines at right
angles to the length of the strip, but on lines inclined from the perpendicular to an
extent proportional to the pitch of the spiral when the strip is coiled into the form
of a bend, so that when so coiled the lines 0-1, 1-2, 2-3, etc., for example,
joining the vertexes of successive pairs of curves will come together end to end
(that is to say, the end 1 of the line 0-1 will join the end 1 of the line 1—2 and
so on) and be in the same line extending longitudinally along the outer curve of
the bend. The "pitch" of the sinuous curvature of the edges of the strip depends
upon the intended diameter of the tube, as it will be obvious that the narrow
portions of the strip come together at the inner, and the broad portions of the strip
come together at the outer, curve of the bend, whilst the difference between the
narrower and the broader portions of the strip will be inversely proportional to
the radius of curvature of the bend. At each end of the strip at opposite sides
the one edge of the strip is left straight for a distance equal to the circumference
of the tube to form the end of the bend, the end a of the strip abutting against the
shoulder a when the strip is bent to the tubular form. The configuration of the
sinuous strip A is marked by means of a templet, and the strip is cut by means of
any suitable shearing machine.
The first stage of the flanging operation is to bend the edges of the strip slightly
in opposite directions, as shown in Figure 2, by passing it between a pair of male
and female rolls B, B', having an angular rib and groove of the form shewn. In
this operation, the shoulder 2 of the lower roller B serves as a fence against
which the edge of the strip is guided, so as to ensure the crease being made
uniformly at a distance from the edge of the strip equal to the intended breadth of
the flange. The strip is passed twice between these and the succeeding two pairs
of rollers, so as to effect the flanging of the two edges of the strip in opposite
directions, with regard to the plane of the strip.
The strip is then passed between the second pair of rolls C, C', Figure 3, having
a rectangular groove c and rib c¹ between which the partially-bent edge of the strip
is passed and by which it is brought to the channelled form shewn in Figure 3. In
this operation, the crease 63 serves as the guide by which a flange c² of uniform
width is turned down at right angles to the plane of the strip A.

page_text: The two edges of the strip having been similarly flanged and channelled, the
strip is passed between the rolls D, D', Figure 4, having a V-groove d and a
semi-V-rib d, as shewn, whereby the flanges care inclined inwards beyond the
perpendicular to the plane of the strip, so as to facilitate the engagement of the
oppositely-flanged edges and their closing down and interlocking in the subsequent
operation of spirally-coiling the strip.
This operation is performed by a pair of rolls E, E', such as shewn in Figures 5,
6, and 7, in which it will be seen that the outer roll E has a pair of circumferential
ribs e with a groove el between, in which the folding down of the interlocked flanges
and the closing of the joint is effected whilst the inner roll E has a plain periphery
curved in the transverse direction of its face, to a radius rather less than the radius
of the outer curve of the pipe bend, so that the joint when completed will project
wholly from the outer surface of the tube whilst the inner surface is plain. In
commencing to coil the strip, the end portion is bent by hand to the intended
circumference of the tube so that the end a abuts against the shoulder a', to which
it may be united by brazing, after which the inwardly projecting flange c², which
commences at a', is caused to overlap and engage with the outwardly projecting
flange, which commences at a², of the other edge of the portion of the strip which
has been already coiled. The strip is fed to the rolls E in an upwardly-inclined
direction, as shewn in Figures 5 and 6, so that its flange may be engaged with the
flange of the portion already coiled, some little distance (say about an eighth of
the circumference of the tube, more or less) in advance of the point of nip of
the rolls E, E', the strip being bent to about the intended diameter of the tube by the
operator in the act of so engaging the flanges. By the revolution of the rolls E,
the work is carried through and the flanges are flattened down and interlocked, as
shewn in Figure 7, whereby a perfectly close folded lap-joint is formed, the feeding-
in of the flat strip and the bending of it to the spiral tubular form by the rolls E
being continuous and concurrent with the union of the portion so fed in with the
portion already coiled into tubular form.
It is necessary in making copper pipe bends to anneal the strip after flanging and
before coiling it and making the joint between the rolls E, E'. The shafts of each
pair of rolls are geared together by spur gear F, as illustrated in respect of the
rolls E El, one of said shafts being driven by worm gear G from a shaft H, geared
with a driving shaft I carrying a pulley provided with treadle-operated clutch gear
for connecting or disconnecting it with the shaft I.
The joint is perfectly steam-tight, but in order to prevent all liability of the joint
opening under high pressures it may be brazed internally at y or externally in the
angle formed between the exterior fold and the adjacent portion of the pipe, or
both at x and y. In making bends of mild steel intended to convey gases at low
pressure, the operation of brazing is of course unnecessary.
Instead of making the oppositely-flanged edges of the strip interlock directly
together, as above described, both edges may be outwardly flanged, as shewn in
Figures 8 and 9, and united by a capping strip K brought to the sectional form
shewn in Figure 8 by drawing in dies. This capping strip K by its inward flanges k
is made to embrace both the outward flanges c³ of the main strip A, and the said
flanges and are flattened down and made to interlock by the pressure of the
rolls E, E', in the act of coiling the main and capping strips together, the final form
of the joint being represented in Figure 9.
In whichever of the above described ways the pipe bend be made, the ends of the
bend would be united to end flanges as usual in making copper pipes.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is-
1. The herein described method of making pipe bends from a strip of sheet
metal, which consists in flanging the oppositely-curved sinuous edges in opposite
directions as described, and then coiling the strip spirally and at same time causing

page_text: the flanges of adjacent convolutions to become interlocked and flattened down, so
as to form a folded lap-joint, by, the pressure of a pair of rolls applied to the joint
in the act of coiling the strip, substantially as specified.
2. The herein described method of making pipe bends from a strip of sheet
metal, which consists in flanging the oppositely-curved sinuous edges in the same
direction, coiling the strip spirally and at same time coiling upon the adjacent
flanges a capping strip having inwardly-inclined flanges and flattening down the
flanges of the main and capping strips, so as to cause them to be interlocked by the
pressure of a pair of rolls applied to the joint, substantially as specified.
3. A pipe bend formed of a sheet metal flanged strip of varying width coiled
spirally to the form of a tube and the adjacent convolutions united by the direct inter-
locking of their flanges or by the interlocking therewith of a flanged capping strip
so as to form a single or double folded lap-joint, substantially as specified.
Dated this 26th day of April 1893.
F. J. CLINCH-JONES,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.