Improvements relating to the Soldering or Uniting of Metals by Electricity and to Apparatus therefor.
Year: 1890

page_text: Date of Application, 25th Mar., 1890-Accepted, 26th Apr., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by Professor ELIHU THOMSON, of Lynn, Massachusetts,
United States of America, Electrician.]
Improvements relating to the Soldering or Uniting of Metals by
Electricity and to Apparatus therefor.
I, HENRY HARRIS LAKE of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex, 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 those processes of uniting metal or other objects which
require the employment of heat to soften or fuse the uniting material that, by after-
wards cooling and becoming set, fixes or joins the objects firmly together.
My invention consists essentially in heating an electric conductor by a current of
large volume and conveying the heat generated therein to the work, which is for that
purpose placed in juxtaposition to or contiguous to the conductor.
My invention is distinguished from prior methods of soldering or uniting metal
objects by the employment of heating currents of electricity in that instead of inter-
posing the objects, one or both, in the circuit of the heating current of electricity, I
cause the current to pass through a heating electric conductor separate from the
objects, but in sufficiently close proximity or contiguity to the work to cause the
object or objects to be heated to the requisite degree for soldering or similar
operations.
My invention consists also in certain apparatus and devices useful in practicing the
method or process described and claimed herein.
In the accompanying drawings:
Fig. 1 is a front elevation of an apparatus suitable for use in practicing my
invention.
Fig. 2 is a side elevation and vertical section through the same.
Figs. 3, 4 and 5 illustrate varieties of work to which my invention is applicable.
Fig. 6 shows a particular form of heating conductor useful in connection with
forming circular joints.
Fig. 7 is a side elevation of work and apparatus illustrating the use of the
device Fig. 6.
Figs. 8, 9 and 10 illustrate apparatus suitable for use in accordance with my
invention, Fig. 10 showing the apparatus as applied to the soldering of the cover of
a tin can.
Fig. 11 shows in plan, and Fig. 12 in edge view, another form of conductor
suitable for forming circular joints and provided with means for electrically insulating
it from the work.
Figs. 13 and 14 show in plan and edge view another form of conductor provided
with an insulated surface and protective face.
Fig. 15 shows in perspective a top view of the switch employed in connection with
the apparatus shown in Fig. 17 in side elevation.
Fig. 16 shows in side elevation and partial section a detail of the construction.
Fig. 17 is a side elevation of an apparatus adapted for rapid work in soldering or
cementing objects.
Referring to Fig. 1 G indicates a generator of any suitable character adapted to
produce or generate electric currents, alternating or continuous, of considerable volume
but of comparatively small electro-motive force, while C, C' are heavy electric con-
ductors connecting such source with a conductive plate or rod C", through which the
heavy current is passed for the purpose of heating such conductor C: The form

page_text: given to the conductor C" varies with the form of the work which is subjected to
heating by it. J J' are jaws or clamps adapted to hold the work between them and
the conductor C".
Upon the faces of the heating conductor C" a thin layer of some insulating material
is preferably applied, such for instanco as mica. I prefer mica because it is not easily
destroyed by heat. The thickness of the layer, as illustrated in the drawing, is some-
what exaggerated.
F is a suitable frame for supporting the parts.
In the operation of soldering or tinning together two pieces of metal N N' they are
first placed in position between one of the jaws as J'and the heating conductor C",
so as to be in jaxtaposition to the latter and exposed to the heat from the same when
such conductor is heated by the electric current. The current is allowed to traverso
the heating conductor C" until the pieces N N' have by conduction received from C"
sufficient heat to melt the tin, solder or other cementing material placed between
them at the joint, after which the current is cut off and the work allowed to cool
under pressure. Or, if desired, the work might be removed without cutting off the
current and before the cement is set. It is better, however, to maintain the pressure
for a time. Suitable clamping screws S S' S″ are applied to the jaw or holder J'for
the purpose of pressing the work and the heating conductor into close and firm
contiguity. Any other holding or clamping devices might be employed for the
parpose.
Figs. 3, 4 and 5 illustrate other kinds of joints which may be soldered by the
employment of suitably formed heating conductors.
In Fig. 4 the pieces to be united by soldering or tinning their surfaces together are
at right angles to each other, one part being bent to overlap upon the other. The two
pieces might be interlocked as indicated in Figs. 4 and 5, their heating surfaces being
coated with proper cementing or soldering material or having such material interposed
between them.
The conductor C might be made circular, as shown in Fig. 6, and would then bo
adapted to use in applying my process to the soldering together of the bodies and lids
of tin cans.
Fig. 7 illustrates the application of the conductor C", to the formation of a circular
joint. N, N', are the two parts to be united, and J, the holder or support therefor.
The heating conductor C", is held in close juxtaposition to the work by means of a
suitable weight W, or other means.
Fig. 10, shows the apparatus organized for soldering a cover to a tin can. The
conductor C", of the form shown in Fig. 9, is provided with a weight W, for holding
it down to the work. The conductor C", is supplied with current from the
secondary C, of the converter or induction coil the primary of which, indicated at P,
derives alternating or other currents from wires or conductors a, b. G, is the usual
mass of iron encircled by the coils of the converter. A tin can N, carried by
support B, is pressed up towards the soldering or heating conductors (", by means
weight W. A handle H, serves to depress the support when the can is to be
of
removed.
In order to protect the mica insulation on the surface of the conductor from
injury, I face it with a thin sheet or piece of metal such as sheet iron, indicated at I,
Figs. 12 and 14. This facing of iron or metal is applied so that it will not form a
path for any of the current flowing in the conductor C". Thus in Fig. 11, the
sheet iron is riveted to the conductor C", formed as a circle, at the points a', b', which
are points of equal potential when the current flows from conductor C, to
conductor C', through the ring C". When the heating conductor is straight, as
in Figs. 13 and 14, the metal facing may be fastened as indicated at a', to the
middle point of the conductor.
In Figs. 15, 16 and 17, I have shown an apparatus that is suitable for use in
uniting a large number of objects of the same form or character such as lids of tin
cans to their bodies. This apparatus is so constructed that one or more pieces are

page_text: undergoing heating while the others are cooling and the necessary pressure to
complete the union is brought to automatically bear upon the work at the proper
moment. C, C, are the conductors of large gauge which connect from the source
of heating current and supply current to terminal blocks A A', insulated from one
another and forming the contacts of a rotary or other switch the contact blocks of
which, indicated at D, D, etc., are carried by a disc that is rotated by means of a
belt B. This belt operates on a wheel fixed to the same shaft with the support for
the blocks D, D. The contact plates D, D, are connected by rods E, E, of
conducting material with the heating conductor C, which is formed as shown in
Figs. 16 and 17, so as to have a number of projecting or heating faces between
the rods E, E.
J', J, indicate a number of clamping jaws or holders corresponding in position
to the heating faces of the conductor (", and mounted as spring actuated followers
in the disc to which belt B is applied. To these followers are applied springs W,
that tend to press them down upon a cam surface H, over which they ride and
which is provided with a depression at a portion of its periphery so as to permit the
jaws J', to be lowered to receive the parts N, to be soldered together. As the
followers move around they ride up on the cam and bring the parts into contact
with the portion of heating conductor immediately over the jaw. As the jaws or
holders rotate with the conductors C, the part of the latter immediately above
the object is brought into position where it will be included in circuit between the
arms A, A', and will be heated, thus softening the soldering or cementing material.
As soon as this takes place the continuance of movement carries the part of the
heating conductor in question out of circuit, and the can surface H, maintains the
pressure until the soldering or cementing material is cooled when, the revolution
having been completed, the pieces are released at the depressed portion of the cam.
The path of the current is through the arm A, down to the heating conductor C, at
the part thereof under the arm A, thence to the other conductor A', and out by
conductor C'.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what I claim is :-
1. The herein described improvement in uniting metal or other objects by the
application of heat, consisting in passing a heating electric current through a
conductor in juxtaposition to the work, as and for the purpose described.
2. In an electric soldering or cementing apparatus, a heating electric conductor
provided with
an insulating surface, such as mica, where it is applied to
the work.
3. In an electric cementing or soldering apparatus, a heating electric conductor
having an insulated surface and a protective face of metal.
4. The herein described method of forming circular joints by the aid of solder or
cement, consisting in applying a circular conductor to the work with the cementing
or soldering material between the objects and passing an electric current of large
volume through such circular conductor in sufficient amount to heat the same to
the requisite temperature, as and for the purpose described.
5. In an electric soldering or cementing apparatus, a circular beating conductor
having its working surface covered with insulating material and provided with a
metal protective face fastened to the conductor at points of equal potential.
6. In an electric soldering or cementing apparatus, a rotary carrier for the objects
to be cemented provided with a series of jaws or holders, a series of heating
conductors or portions of conductor opposite the same and a rotary electric switch
for including such conductors in circuit one after the other.
7. The combination with the series of clamps or jaws J', carried on a suitable
rotary support of a cam, H, upon which they ride, a series of heating conductors
opposite the jaws and an electric switch for including the same successively in circuit,
ps and for the purpose described.

page_text: 8. The herein described improvement in uniting objects of metal or other material
by the application of heat, consisting in heating them by an electric current passed
through a conductor in juxtaposition to the objects while they are pressed together
and permitting the pieces to cool under pressure.
Dated this 25th day of March 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.