Improvements in the Manufacture of Brazed Steel and other Brazed Metal Tubes.
Year: 1896

page_text: Date of Application, 9th Dec., 1896
Complete Specification Left, 11th Oct., 1897-Accepted, 13th Nov., 18971
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Brazed Steel and other Brazed
Metal Tubes.
I, FRANK MOORE, of 5 Court, 3 House, Stoke Street, Ladywood, in the City of
Birminghain, Cased Tube Solderer, do hereby declare the nature of this Invention to
as follows:-
This Invention has reference inore particularly to brazed steel tubes but it is also
By my
applicable to brazed tubes of copper aluminium brass or other metal.
Invention I am enabled to obtain a very strong brazed seam or joint and to inake the
tube perfectly sinooth on the outside that is to say there is no external longitudinal
rib or projection along the joint or seam. My Invention is applicable to tubes of any
section whether cylindrical D-shaped or of other section and is particularly applicable
to those steel tubes which are used in the construction of the frames of bicycles motor
carriages and other vehicles.
A brazed tube inade in accordance with this Invention is made from a strip of
sheet steel or other metal or alloy which is rather wider than is the circumference of
the tube so that when the strip is bent into the tubular form the edges of the strip
will overlap, one of the said edges being outside the tube and the other edge inside
the same. The strip is rebated at a short distance from its inside edge so that the
outer edge will lie in and is brazed to this rebated part thus making a comparatively
wide brazed joint or seam and the tube perfectly smooth on the outside.
A tube having its brazed joint made as above described may be produced in various
ways. For instance I may first turn up an open jointed tube from a parallel strip of
sheet steel by drawing the strip through rolls or through a die on a draw bench as is now
done with the open jointed inside iron or steel tubes of cased brass tubes. The rebate
along the one edge is then formed by pressure along that edge as by a roll which
presses that edge of the tube down into a longitudinal groove forined along a mandril
inside the tube or along a stationary plug over which the tube is drawn. The two
edges of the tube are now caused to overlap one another by passing the tube through
rolls or by drawing the same through a die. The tube is now bound together by
wire at intervals as is done when making other brazed tubes and the joint is brazed
in a brazing muffle or by other means. After the brazed joint has been dressed on
the outside by filing or by other means the tube is drawn through a die on a draw
bench so as to harden and straighten the tube and finish the same to a true circle or
other desired form. In this final drawing process the tube may be drawn on a
mandril which has a longitudinal groove corresponding with the rib inside the tube,
or the said tube may be drawn off a plug which has also a groove corresponding with
the said internal rib, or the tube may be drawn through the die without a mandril or
plug.
According to another method of producing my improved tube the strip has one
edge rebated by rolling or by pressure between dies or by other means before the strip
is bent into the tubular form. The tube is then annealed if necessary to burn off the
oil and then pickled and the joint brazed and the tube finished by drawing through a
die to harden and straighten the same as stated above.

page_text: Steel tubes made from sheet steel of good quality with the brazed joint formed
with one rebated edge as above described are as strong or almost as strong as and are
much cheaper to manufacture than are cold drawn seamless steel tubes.
Dated this 8th day of December 1896.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Brazed Steel and other Brazed
Metal Tubes.
I, FRANK MOORE, of 5 Court, 3 House, Stoke Street, Ladywood, in the City of
Birmingham, Cased Tube Solderer, 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 :-
This invention consists in making brazed sheet steel tubes and other brazed sheet
metal tubes in the manner herein described whereby I am enabled to obtain a very
strong brazed seam or joint and to make the tube perfectly true on the outside,
that is to say, there is no external longitudinal rib or projection along the joint or seain.
My Invention is applied to tubes of all sections whether cylindrical D-shape oval
or other shape and is particularly applicable to making brazed steel tubes for use in
the construction of the frame of cycles motor cars and other vehicles.
I will describe my Invention by referring to the accompanying drawing on which
Fig. 1 is a cross section of a cylindrical brazed tube constructed from a strip of sheet
metal in accordance with this Invention; Fig. 2 is a cross section of the strip of
metal from which the tube represented by Fig. 1 has been formed and Figs. 3 and 4
shew two stages in the manufacture of the said tube; Fig. 5 is a front elevation of a
pair of rolls and special mandril which I employ in the manufacture of the said tube
and Fig. 6 is a plan and Fig. 7 is a sectional side elevation of the said rolls and
mandril shewing also the guide which I use therewith for turning up the strip into
the tubular form the said strip being also shewn by these figures and Fig. 8 is a
cross section on line X X of Fig. 7.
The same letters of reference indicate the same parts in all the figures of the
drawing.
In carrying out my Invention I take a strip A of sheet steel (Fig. 2) or a strip of
other metal or alloy and which is rather wider than is the circumference of the
finished tube represented in Fig. 1 so that the edges of the strip will overlap to form
the joint. By passing the strip A through rolls I bend and rebate one edge a¹ of the
strip A as shewn in Fig. 3 so that when this strip is turned into a tube as hereinafter
described and shewn by Fig. 1 the other edge a² of the strip will lie in the rebated
edge the latter forming a rib all along the inside of the tube as shewn in Fig. 1.
In order to turn the rebated strip A shewn by Fig. 3 into the tubular form represented
by Fig. 1, I employ a round inandril B of corresponding size to the inside of the
required tube and this mandril B has a longitudinal groove 61 all along it of the
proper size to admit the rebated edge a¹ of the strip A. I employ a pair of grooved
rolls marked C1 C2 which together form a pass or hole corresponding in size and shape
with the outside of the required tube A. At the front of these rolls and preferably
fixed to the housing or carriage which supports them, I provide an inclined guide
such as D having a central hole ¹ somewhat larger than the outside of the required
tube. The interior of this guide D gradually widens out from the hole d¹ to its other
end where it becomes flat or almost flat. The rolls CC with the guide D are
fixed on a draw bench. The front end of the strip D is tagged and bent into a

page_text: trough section and with the mandril B is started through the guide D and rolls C
the rebated edge a¹ of the strip A fitting in the groove b¹ of the mandril so that the
guide D and the rolls gradually bend up the strip A and close it round the mandril B
the rebated edge a' of the strip A fitting in the groove b' and the other edge a
of the strip A being closed down upon this rebated part so that the tube when it has
passed through the rolls C C will have the form represented by Fig. 1 with the
edge a fitting in the rebated edge . After the mandril has been removed these
edges are brazed together in the usual way the tube meanwhile being bound together
by wire at intervals as usual. The hole through which the strip A is drawn is by
preference made with the groove 3 as shewn so that the edge a will rise into this
groove and be well above the other edge a¹ so as to be closed down on to the same by
the rolls C¹ C².
After the brazed joint has been dressed by filing or other means the tube is or
may be drawn through a die or through rolls to harden and straighten the tube and
finish the same to a true circle or other desired form.
When applying my Invention to the manufacture of brazed tubes or other section
than round such for instance as D-shape or oval I prefer to first make a round tube
as above described and then pass the round tube through ordinary rolls which roll the
tube to the particular section required.
Instead of the rolls C1 C2 I may employ an ordinary die with a round hole to draw
the tube through in combination with the grooved mandril B.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. Making a brazed steel or other brazed metal tube from a strip of sheet metal
which is rather wider than the circumference of the required tube by first rolling a
rebate along one edge of the strip and then passing this rebated strip through a
guide and rolls or a die which bend the strip into a tubular form and close the rebated
edge of the strip under the other edge and in a longitudinal groove formed in a
mandril which supports the inside of the tube all substantially as set forth.
2. In the manufacture of brazed steel or other metal tubes of the kind herein
referred to form a strip of sheet metal which has a rebate rolled along one edge, the
employment of a parallel mandril provided with a longitudinal groove b¹ to support
the inside of the tube and receive the rebated edge in combination with rolls or a
die through which the mandril and strip are drawn so that the rolls or die bear upon
the outside of the tube and press the same around the inandril and in the groove of
the same substantially as set forth.
Dated this 8th day of October 1897.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.