IMPROVEMENTS IN THE MANUFACTURE OF BENT OR CURVED SOFT Metal TUBES AND APPARATUS USED THEREPOR
Year: 1875

page_text: LETTERS PATENT to Edmund Edwards, of the Firm of Edwards
and Co., 38, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Engineers and Patent Agents, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF BENT OR CURVED SOFT Metal
TUBES AND APPARATUS USED THEREPOR." -A communication from abroad
by Robert Mitchell, of the City of Montreal, in the Dominion of
Canada
PROVISIONAL SPECIFICATION left by the said Edmund Edwards at
the Office of the Commissioners of Patents, with his Petition, on
the 29th October 1875.
İ, EDMUND EDWARDS, of the Firm of Edwards and Co., 38, South-
ampton Buildings, Chancery Lane, in the County of Middlesex,
Engineers and Patent Agents, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF BENT OR CURVED SOFT
METAL TUBES AND APPARATUS USED THEREFOR," to be as follows:―
This Invention, although having reference to all kinds of bent soft

page_text: metal tubes, is applicable more particularly to the bends, elbows,
syphons, and traps formed of lead pipe, and used by plumbers and in
many other trades, and has for its especial object the formation of these
curved pipes in such a manner as to obviate entirely the disadvantages
inseparable from elbows or other bends manufactured in any of the usual
ways.
One process by which these pipes are at present manufactured is
by working them out of sheet lead by hand, this being both slow and
expensive. Another method of making these bends is by casting them
in moulds, but such castings are both heavy and difficult to set should
any alteration be required in fitting them, and are also very objectionable
from the fact that the metal becomes open and porous to such an extent
as to allow liquid to pass through its substance.
This Invention consists in improvements in the method of forming
such curved pipes, by which all the defects above mentioned are
obviated. It consists, firstly, of casting the metal tube from which the
bend is to be made with a surplus of metal on that part which is to
form the outside of the curve, the cross section of the pipe at this part
showing a gradually increasing thickness of metal on both sides from
the line of the inside of the curve round to the opposite point on the
outside. The tube thus cast is placed upon a mandril, and the thickened
portion is then subjected to the action of revolving dies (or any
analogous device), by which the metal therein is beaten or drawn (in a
manner similar to the spinning of sheet metal in the lathe) so as to
reduce it and bring it to an even thickness with the other parts of the
pipe without increasing its diameter, so that it is evident that as there ;
is more metal to stretch out on the upper part of the tube than on the
sides, and nothing at all underneath, the wall of the pipe on the upper
side where this operation is performed must be lengthened longi-
tudinally, thus forming a bend or elbow downwards in the tube, the
length or radius of the curve being determined by the length and massa
in the thickened part of the casting.
Where, as in a "trap," a double curve is to be formed, the extra
thickness of metal is cast on both sides of the pipe from which the trap
is to be made, at points corresponding to those which the outside curves
will occupy, and after one bend has been formed by the milling or
drawing process above described, the half-finished pipe will be with-
drawn from the mandril, reversed, and the second bend formed in the
same way, the forming dies playing inside the curves already finished.

page_text: It is obvious that a curved pipe thus formed being subjected in the
process of making to the compacting and strengthening action of
beating and drawing will be greatly superior to those cast in moulds,
the compactness of the metal imparted by the process of manufacture
giving the curved walls of the tube greater strength, detecting any im-
perfections that may exist in the casting, and closing all minute apertures
not observed.
The improved apparatus which I prefer to use to perform the process
above mentioned is constructed as follows:-I tako a frame for the
machine of cast iron or other suitable material, in which are formed
bearings for a transverse driving shaft rotated by a pulley or other con-
venient means, and provided with a fly wheel to equalize the motion.
Bevilled wheels gearing with other bevel wheels impart motion to two
diagonal shafts arranged at suitable angles radially, and at right angles
to a mandril, which is arranged in suitable bearings, and carries the
pipe formed as above described which is to be operated on. Upon the
two diagonal shafts, actuated as described, are arranged revolving
double-faced dies, herein-after more particularly described. A third
fixed dio is arranged beneath the other two revolving dies, and supports
one end of the mandril, the other end of which is carried in a post
pivotted to lugs formed at the rear end of the bed plate of the apparatus,
this end of the mandril being screwed and provided with jam nuts to
adjust the length exactly to what is required.
The pipe to be operated upon is placed upon the mandril between the
fixed die and the two revolving dies, and mechanism is provided for
feeding to the dies the pipe as follows:-Upon the mandril slides freely
a feed block arranged to receive the rear end of the pipe, and provided
with a clamp to hold it in place. A slide moving in a slot in the bed
plate, and having a projection fitting into a corresponding aperture in
the feed block, causes the latter to move backward and forward simul-
taneously with the slide. This slide has a threaded opening or nut
formed in it to receive a feed screw, which is rotated by means of a
ratchet wheel secured to it, and actuated by a pawl pivotted to an arm
or pawl carrier, to which motion is imparted from an excentric secured
on the driving shaft of the apparatus by means of a rod connected to
one arm of a bell crank or bent lever, to the other arm of which is
attached a rod having its other end fastened to the pall carrier. This
arrangement for transferring the action of the excentric to the pall

page_text: carrier may in some instances be advantageously varied, and the bent
lever be arranged to receive and transmit the motion of the excentric
without the intermediate rods. The pipe to be bent is placed on the
mandril and feed block, and is secured in place by the clamp, and the
feed screw being rotated by the action of the excentric upon the lever,
transmitted through the pall carrier and pawl to the ratchet wheel, the
slide and feed block are thereby moved forward, thus constantly feeding
the pipe to the dies, which are revolved by the action of the bevilled
wheels first described. The lower or fixed dic of these occupies a length
of about three-sevenths of the circumference of the pipe, the two upper
dies operating upon the remaining four-sevenths, their lower points just
meeting the upper ends of the lower dic, and with it entirely embracing
the circumference of the tube to be bent. Each of these revolving dies
or beaters has two faces differing slightly in length from each other, and
so arranged that in working the longer face on the one die shall strike
the pipe simultaneously with the shorter one of the other die, and vice
vers, thus supplementing each other and working slightly across each
other's path, by this means avoiding the raising of a fin or ridge on the
tube between the ends of the two double dies, the use of the two dics
thus working also obviating any undue drawing or straining of the sides
of the tubes. The exact distance of these dies from the mandril is
adjusted by means of set screws, and they are set slightly slanting or
bevilled across the pipe so that no scraping action can take place, the
faces working on the lead like burnishers in the manner and producing
the effect above described.
Te docised brushes serving the two-fold purpose of lubricating and
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edmuud Edwards in the Great Seal Patent Office
on the 29th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
EDWARDS, of the Firm of Edwards and Co., 38, Southampton Buildings,
Chancery Lanc, in the County of Middlesex, Engineers and Patent
Agents, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of October, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reigu, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Edmund Edwards, Her special
licence, that I, the said Edmund Edwards, my executors, administrators,
and assigns, or such others as I, the said Edmund Edwards, my exc-
cutors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for “Improvements
IN THE MANUFACTURE OF BENT OR CURVED SOFT METAL TUBES AND APPARATUS
USED THEREFOR," a communication to me from abroad by Robert
Mitchell, of the City of Montreal, in the Dominion of Canada, upon
the condition (amongst others) that I, the said Edmund Edwards, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edmund Edwards, do hereby declare
the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in
and by the following statement and accompanying Drawing (that is to
say):
:-
This Invention although having reference to all kinds of bent soft
metal tubes is applicable more particularly to the bends, elbows,
syphons, and traps formed of lead pipe, and used by plumbers and in
many other trades, and has for its especial object the formation of these
curved pipes in such a manner as to obviate entirely the disadvantages
inseparable from elbows or other bends manufactured in any of the usual
ways. One process by which these pipes are at present manufactured
consists of working them out of sheet lead by hand, this being both slow
and expensive. Another method of making these bends is by casting
them in moulds, but such castings are both heavy and difficult to "set"
should any alteration be required in fitting them, and are also very

page_text: objectionable from the fact that the metal becomes open and
such an extent as to allow liquid to pass through its substance.
porous to
This Invention consists of improvements in the method of forming
such curved pipes, by which improvements all the defects above
mentioned are obviated. It consists, firstly, of casting the metal tube
from which the bend is to be made with a surplus of metal on that part
which is to form the outside of the curve, the cross section of the pipe
at this part showing a gradually increasing thickness of metal on both
sides from the line of the inside of the curve round to the opposite point
on the outside. The tube thus cast is placed upon a mandril, and the
thickened portion is then subjected to the action of revolving dies (or
any analogous device), by which the metal therein is beaten or drawn (in
a manner similar to the spinning of sheet metal in the lathe) so as to
reduce it and bring it to an even thickness with the other parts of the
pipe without increasing its diameter, so that it is evident that as there
is more metal to stretch out on the upper part of the tube than on the
sides, and nothing at all underneath, the wall of the pipe on the upper
side where this operation is performed must be lengthened longitudinally,
thus forming a bend or elbow downwards in the tube, the length or
radius of the curve being determined by the length and mass in the
thickened part of the casting.
Where, as in a "trap," a double curve is to be formed, the extra
thickness of metal is cast on both sides of the pipe from which the trap|
is to be made, at points corresponding to those which the outside curves
will occupy, and after one bend has been formed by the milling or
drawing process above described the half-finished pipe will be with-
drawn from the mandril, reversed, and the second bend formed in the
same way, the forming dies playing inside the curve already finished.
It is obvious that a curved pipe thus formed being subjected in the
process of making to the compacting and strengthening action of
beating and drawing will be greatly superior to those cast in moulds,
the compactness of the metal imparted by the process of manufacture
giving the curved walls of the tube greater strength, detecting any
imperfections that may exist in the casting, and closing all minute
apertures not observed.

page_text: hension of the same to the Drawings hereto annexed, in which similar
letters of reference indicate like parts, and where Figure 1 is a front
view of the machine, Figure 2 is a side view of the same taken on
line A, B, Figure 1; Figure 3 is a plan, and Figure 4 is a sectional
clevation on line C, D, Figure 3. a is the frame of the machine of cast
iron or other suitable material, in which are formed bearings for the
transverse driving shaft b, rotated preferably by the pulley c or other
convenient means, and provided with a fly wheel d to equalize the
motion. Bevilled wheels e, e', gearing with other bevil wheels ƒ ƒ³,
impart motion to two diagonal shafts g, g', arranged at suitable angles
radially, and upon which are mounted respectively the revolving double-
faced dies, , i being the lower die fixed in a suitable bed or casting.
These dies will be herein-after more particularly described. k is the
mandril supporting the pipe to be operated on; one ond of k lies in the
die i, and the other is carried in a post ¹ pivotted to lugs /* formed at
the rear end of the bed plate secured to the front frame a, this end of
the mandril being screwed and provided with lock nuts to adjust the
length exactly to what is required.
The mechanism provided for feeding to the dies the pipe to be operated
upon is as follows:-Upon the mandril k slides freely the feed block m,
arranged to receive the rear end of the pipe, and provided with a
clamp m' to hold it in place. n is a slide moving in a slot in the bed
plate, and having a projection n' fitting into a corresponding aperture
in the feed block m, so as to cause the latter to move backward and
forward simultaneously with the slide. This slide n has a threaded
opening or nut formed in it to receive the feed screw o, which is rotated
by means of a ratchet wheel. p secured to it, and actuated by a pawl q
pivotted to the arm or pawl carrier r, arranged as shown, to which
motion is imparted from the excentric 8, secured on the shaft 6 by means
of a rod & connected to one arm of a bell-crank or bent lever t, to the
other arm of which is attached a rod 8³, having its other end fastened to
the pawl carrier r. This arrangement for transferring the action of the
excentric & to the pawl carrier r may in some instances be advan-
tageously varied, and the bent lever be arranged to receive and transmit
the motion of the excentric without the intermediate rods. The pipe
to be bent is placed on the mandril k and feed block m, and is
secured in place by the clamp m', and the feed screw o being rotated
by the action of the excentric s upon the lever t, transmitted through

page_text: the pawl carrier and pawl q to the ratchet wheel p, the slide n and
feed block m are thereby moved forward, thus constantly feeding the
pipe to the dies, which are revolved by the action of the bevilled
wheels e, f, e¹, f'. The lower or fixed die i of these occupies a length of
about three-sevenths of the circumference of the pipe, the two upper
dies, ', operating upon the remaining four-sevenths, their lower points
just meeting the upper ends of the lower dic, and with it entirely
embracing the circumference of the tube to be bent. Each of these
revolving dies or beaters has two faces differing slightly in length from
each other, and so arranged that in working the longer face on the one
die shall strike the pipe simultaneously with the shorter one of the
other die h', and vice versa, thus supplementing each other, and working
slightly across each other's path, by this means avoiding the raising
of a fin or ridge on the tube between the ends of the two double
dies, the use of the two dies thus working, also obviating any undue
drawing or straining of the sides of the tubes. The exact distance of
these dies from the mandril is adjusted by means of set screws x, and
they are set slightly slanting or bevilled across the pipe so that no
scraping action can take place, the faces working on the lead like bur-
nishers, in the manner and producing the effect described at length in
the foregoing portion of this Specification.
If desired, brushes serving the two-fold purpose of lubricating and
cleaning the dies may be used in connection with them, as shown at z,
Figure 1.
Having now fully described the Invention and the manner in which
it is to be performed, I claim,-
Firstly. The method or art of making bent tubes of soft metal of a
single piece of metal without a seam by casting a tube with surplus
metal where the outside of the bend is to be, and then forming the
bend by beating or rolling the surplus metal to a uniform thickness
with the rest of the tube without increasing the diameter, substantially
as described.
Secondly. The combination with the mandril k and die of the two
double-faced revolving dies h, h¹, the construction and combination of
the parts and the mode of operation being substantially as described and
shewn in the Drawing.

page_text: Thirdly. The combination of the feed block and feed screw o,
and the excentric 8, imparting motion thereto through intermediate
mechanism, substantially as described and shewn in the Drawing.
In witness whereof, I, the said Edmund Edwards, have hercunto
set my hand and scal, this Twenty-eighth day of April, in
the year of our Lord One thousand oight hundred and seventy-
six.