Improvements in and connected with Brazing Metallic Joints.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Brazing Metallic Joints.
I, PHILIP LOUIS RENOUF, of 19 and 20, Holborn Viaduct, in the City of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
It is usual in brazing together two metal articles to bring them together tightly
and then apply brass or copper or spelter with a flux to the outside and by melting
cause it to run through the joint from outside. This necessitates the removal of
the superfluous brazing and scale, besides involving some uncertainty with regard
to the perfect running of the brazing where it is required.
I seek to provide means for placing the copper, brass or spelter between the
two articles to be joined. For this purpose one or both of them are provided
with grooves or recesses which are filled with the brazing material.
Sometimes the articles are coated with a deposit of metal in solution and brought '
together before the deposit has solidified; sometimes they are brought together
and the solution inserted in a cavity or cavities provided between the contacting
surfaces.
In the case of tubular joints such as are used on velocipede frames, I press, spin
or roll longitudinal, transverse, or spiral grooves on the tubes, and fill them with
the brazing material, then insert same into the pockets or hollow lugs and direct
a jet or stream of heat across the joint until the brazing material flows.
For
this purpose I prefer to employ an electric current or one or more electric arcs.
In the case of male and female joints it is sometimes convenient to provide the
cavities on the female inside of the female joint especially where it is formed by
folding the lug out of sheet metal.
Dated this 4th day of June 1897.
Improvements in and connected with Brazing Metallic Joints.
I, PHILIP LOUIS RENOUF, of 19 and 20, Holborn Viaduct, in the City of London,
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:-
It is usual in brazing together two metal articles to bring them together tightly
and then apply brass or copper or spelter with a flux to the edges of the joint
and by melting to cause it to run from the outside to and through the inside of
the joint.
This necessitates the removal of the superfluous brass, scale and dirt
from the fire besides involving some uncertainty with regard to the perfect
running of the braze where it is required. I therefore, instead of applying the
[Price

page_text: brass to the outside of a joint and trying to make it run in, apply it to the inside
of the joint and cause it to flow outwards. For this purpose I provide cavities
or grooves in one or both of the articles to be joined for the purpose of acting
as retainers for the fusible metal. In the case of joints with tubes such as are used
on velocipedes the most convenient way is to roll or spin a groove into the inner
member mostly the tube itself; but where the lugs are formed out of folded and
pressed sheet it is easy to press the retaining spaces into the latter before folding.
The retaining spaces may take the shape of semi-circular or oblong indentations
or of circular or spiral grooves or any shape that is easily adapted to repetition
work and the fusible metal is cast, pressed or drawn so as to fit into these spaces.
The parts to be brazed are cleaned and treated with boracic acid or other suitable
flux, the spaces filled with the fusible metal, the parts tightly brought together
and the brazing heat applied; thus the fusible metal is practically enclosed
between the metal parts as in a crucible and all gas and impurity kept from the
braze until it is completed. For tubular joints a split ring of brass forms
the most convenient kind of filler for a circular groove. Heat may be applied
by means of one or more blowpipes; I prefer however to employ electric brazing
either by placing the joint to be made in an electric circuit of such strength
that the metal parts offer the greatest resistance to the passage of the current
and thereby get heated, or by directing one or more electric arcs against the
parts concealing the fusible metal. Referring to the drawings:
a
دو
spun
A and B are two tubes which are joined by insertion into the. Tee-lug C.
According to the construction shewn here, the tube A has a groove
into its circumference ant the shank of the lug is provided with an internal
groove "c," these grooves being filled up by the brass split rings E and D res-
*pectively, the former having been sprung over tube A and the latter having been
sprung into groove "c" before the tubes were placed into position; the tubes and
the inside of the lug having been cleaned and washed with boracic acid the joint
is ready for brazing. It is evident that when the outsides of the grooves containing
the brass rings are encircled with a sharp flame of gas or are heated up by an
electric current or by an electric arc, the rings D and E will melt and flow through
the contacting surfaces of the tubes and the lug, leaving the grooves as hollow
circular girders.
Capillarity will keep the molten brass where it is required, the strength of the
joint will be greatly assisted by the excellence of the fit."
Of course it is immaterial for the purposes of brazing which of the articles to
be joined is made to contain the fusible metal. I am aware that grooves or
channels have been used to give flowing solder a "lead" and also that molten
metal has been forced into grooves provided with holes for that purpose; but
in these case the flow of solder has been made from the outside of the joint to the
inside with the object of filling the grooves or channels; I therefore declare that
what I claim is:-
1. On metal articles to be brazed providing cavities for the purpose of receiving
the solder in an unmolten state in the manner substantially as described.
66
ور
2. The tube A provided with a cavity a such cavity containing the solder
before the action of brazing.
3. The split brass rings D or E in the combination with containing grooves for
the purpose described.
4. The combination of an electric current or an electric arc with metal cavities
containing fusible metal in the manner and for the purpose described.
Dated this 4th day of April 1898.
PHILIP LOUIS RENOUF.