Improvements relating to Welding, Brazing, or otherwise Joining Metal Strips, Bars, Rods, and the like by Electricity, and to Apparatus therefor:
Year: 1891

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by HERMAN LEMP and LOUIS M. SCHMIDT, both of
Lynn, Massachusetts, United States of America.]
Improvements relating to Welding, Brazing, or otherwise Joining
Metal Strips, Bars, Rods, and the like by Electricity, and to
Apparatus therefor:
.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent
Agents, 45, Southampton Buildings, in the County of Middlesex, do hereby
leclare 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 process of forming longitudinal metal joints in which
the heating necessary to obtain the joint is produced by means of a current of
electricity and the welding or joining action is obtained by force expanded in a
direction practically at right angles to the length of the pipes or pieces to be
joined.
My invention is especially applicable to the welding, brazing or otherwise joining
of separate strips, bars, rods and the like, of metal side by side, and consists
essentially in feeding the work longitudinally through suitable devices in proper
manner to cause the parts or pieces to be forced together, and at the same time
passing the heating electric current longitudinally through the parts or portions of
the work approaching the devices by which the pressure or other force is applied.
The means for applying the force that shall effect the welding or soldering at the
joint may be pressure rolls, hammers or other devices for applying suitable
mechanical force. I prefer, however, generally to employ pressure rolls or other
pressure devices.
In the operation of my invention the work in which the longitudinal joint is to be
formed is given a continuous movement and the heat and welding action applied
continually and simultaneously as the work moves through the machine.
In carrying out my invention I may use the pressure devices themselves as the
means for making the electrical connection with the work at one point, a con-
nection being made at another point by rollers or other devices, as desired, or the
pressure rollers or similar devices may be out of the circuit and a current fed into one
piece at a point removed from the pressure device through such piece to the point
of contact with the other or others and then through the latter and out by another
device making connection alone with such latter picce or pieces. While I prefer
to employ contact rollers for passing the current into and out of the work I do not
confine myself to such device, but may employ any means for making electrical
connection with the work. The current may be passed through the parts or
portions of the work so that it shall flow through such parts or portions in
series or in multiple or parallel circuit. Both ways are herein described and
illustrated.
In another suggested process for electrically joining metal strips of all kinds,
the strips are in continuous movement, and the current is applied to the stock by
means of rollers; but in the said process the current is made to flow through the
stock in a direction at right angles to its length and the direction of movement, or
transversely from one side to the other of the pressure devices, while in this process
the current travels longitudinally. In such former process the heating takes
place only while the metal passes between the rollers that effect the joining
while in the process forming my invention the heating is extended over some
length of metal and it becomes hot before it comes into contact with the
welding rolls.

page_text: It is evident that in the other process referred to in order to attain a welding
temperature, a current of immense volume must be used and the blanks must move
very slowly. Also, when using thin strips, the cooling effect of the contact rollers
is almost as great as the heating of the current and it is impossible to obtain a good
welding temperature. In my process the rapidity of operation is much greater,
and the rollers liave comparatively small cooling effect, as will be seen further
on. The process may be applied to securing ribs to metal plates, to brazing
or soldering irregular shapes to plain backgrounds, to welding, brazing and
soldering pipes and tubes longitudinally, to uniting strips of dissimilar metal, and
to other work.
In the accompanying drawings, I have illustrated apparatus which may be
employed for joining metal strips, bars or rods according to my invention.
Figure 1 is a side elevation of one form of apparatus and
Figure 2 is a plan view thereof.
Figure 3 is a side elevation of another arrangement of mechanism suitable for
carrying out my invention.
Figure 4 is an end elevation of the same, and Figure 5 is a plan view.
The source of electric current may be any desired apparatus suitable for develop-
ing and furnishing a current of the proper strength or volume. I prefer to
employ, however as a source of current a transformer having a primary of a
comparatively large number of turns traversed by alternating currents and a
secondary consisting of a slit and heavy bar or mass of copper the two ends of
which form the poles of the apparatus and deliver the heating electric currents to
the work. It is usual in the art to make such a secondary bar from a slit
casting of copper having a groove in its side that receives the primary wire.
A. secondary bar of the usual form is indicated at 17, and the devices that deliver
current to the moving metal pieces are mounted directly on the terminals of said
secondary bar.
In the arrangement illustrated in Figures 1 and 2, the current is passed in series
through the two strips or pieces of metal 10, which are to be joined together.
11, 12, 13, 14, are contact rollers. The roller 12, is mounted in a 'bracket or
support 2, preferably integral with the copper secondary 17, and roller 11, is
mounted upon a similar support 1, that, by means of a screw 5, may be adjusted
towards the opposite roll 12. The support 1 is in contact with the same terminal
of the secondary as roller 12, and slides thereon in suitable bearings. Rollers 13, 14
are similarly mounted on the other terminal of the secondary in supports 3, 4, and
adjusting screw 6, serves to move the roller 14, towards the opposite roller 13.
These parts are preferably of the same metal as the secondary, that is to say;
copper. By means of the screws 5 and 6, adjusting the rollers 11 and 14, the
contact may be varied and different sizes of stock provided for. In this arrange-
ment the contact rolls 11 and 12, represent one terminal of the circuits, and the
contacts 13, 14, the other terminal of the circuits of the source of currents.
The devices for pressing or forcing the two strips 10, together are illustrated in
Figure 2, and are preferably mounted upon a table insulated from the transformer.
These pressure devices consist in the present instance simply of rollers 15, 16,
which are of steel or other durable material and are mounted in proper bearings 7
and 8, of the same design as 1 and 2. The screw 9, acts upon the movable casting
or support 7, for the purpose of adjusting the rollers 15, 16, with relation to one
another. The work may be drawn through the rollers 15, 16, in the direction of
the arrow, by any suitable means, or rotation may be imparted to the rollers them-
selves, as well understood in the art of metal working: The small arrows indicate
the direction in which the current will flow through the pieces 10.
In using the apparatus the two strips 10, to be joined are placed in position
between the contact rolls forming the terminals of the source of current and their
ends are brought into contact with one another between the rolls 15, 16. The pressure
screw 9, is then moved to clamp them firmly together between the rolls after
which, on turning on the current, the pieces will become heated' between the
:

page_text: point of application of the pressure devices and the terminals of the source of
Current. The pieces now being moved continually through the pressure devices
in the direction of the arrow will be united thereby and fresh portions of the
pieces to be united will be continually heated in the part included, for the time
being, in the electric circuit for the transformer which feeds the current
longitudinally through the strips or pieces 10.
It is obvious that the same process might be applied to the joining of any
number of strips together at once, the strips or pieces being placed upon one
another and fed between the pressure devices or other means for uniting them by
laterally applied force.
In the arrangement shown the current passes in series through the parts of the
work, but it might be made to pass through the strips, pieces or portions of the
work to be joined in parallel circuit as illustrated in Figures 3, 4 and 5, where I
have shown contact making devices of the same general character mounted upon
the terminals of the secondary 17, but differently arranged with relation to one
another so that the work will be fed from one pair of rolls as 11 and 12, to and
through the other pair 13 and 14. The rollers are a little differently mounted in
this case, one of thein, as 12, being carried in a slide which moves in a casting
that is continuous with the part 1, carrying the opposite roller.
The blanks or strips 10, are fed from one pair of rollers 11, 12, forming one
terminal of the secondary to and through the other pair 13, 14 in the direction
indicated by the arrow Figure 5. In this operation it is obvious that the current
will flow through the two strips or parts of the work in parallel circuit but, as
before, the parts or pieces are heated by current passing longitudinally through
the portions of work which are approaching the pressure or other devices for
forcing them together. When the apparatus shown in Figures 3, 4 and 5 is.
employed the contact rolls 13, 14, may serve also as the pressure devices and in
fact should be preferably used as the means for forcing the parts of the work into
union.
The
It is obviously not necessary to the carrying out of my invention that the two
parts of the work when the current is passed longitudinally through the same in
parallel should be fed from the same transformer or source of current, since
obviously each portion might be fed with current from a separate source.
devices I have described for making electrical contact with the work are effective
for the purpose, though the connection might be made by flat or rubbing
surfaces and the contact portions or surfaces of the apparatus might be carbon
instead of copper. It will be observed that in my process the heating commences
sometime before the application of the pressure or other force for uniting the parts
and that the metal has time to reach a high temperature even though it be moved
moderately fast.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is :-
First. The herein described improvement in uniting strips, bars or rods of metal
longitudinally by welding, soldering, brazing or cementing, consisting in feeding
them while lapped upon one another between suitable pressure rolls or devices
arranged to squeeze or force them together and at the same time passing a heating
electric current longitudinally through such pieces at parts thereof between the
point of pressure and points removed therefrom in the direction from which the
material is being fed.
Second. In an electric soldering or welding apparatus the combination, sub-
stantially such as described, of two pairs of pressure rolls 13, 14, 11, 12, arranged
in line with one another so that the material may be fed through them from one
pair to the other, said pairs of rolls forming respectively opposite terminals or
electrodes of a source of heating current.
Third. The combination, substantially such as described, with a transformer

page_text: secondary adapted to deliver currents of large volume for heating purposes, of two
pairs of rolls or pressure devices mounted on the terminals of said secondary in
line with one another so that strips, bars or pieces of metal to be united may be fed
through such pairs of rolls from one to the other.
Fourth. The combination with a transformer secondary adapted to deliver
current of large volume, of pressure rolls mounted on one terminal of such
secondary, and contact devices mounted on the other terminal in line with the
first so that the material may be fed longitudinally through the contact devices
and between the pressure rolls as and for the purpose described.
1001
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.