Improvements relating to the Heating of Metals and other Materials by Electricity.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Heating of Metals and other Materials
by Electricity.
I, MARK WESLEY DEWEY, of 150 North Salina Street, in the City of Syracuse,
State of New York, United States of America, Electrician, do hereby declare the
nature of my invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My present invention consists of an improved method for electrically heating bars
and blanks for welding and working purposes.
Said bars and blanks may be of electric conducting or non-conducting materials
and the working operations may be soldering, brazing, bending, cementing or any
other desired operation.
Some of the advantages of my method are, that a weaker current may be employed,
the same strength of current may be used for work of various sizes, blanks of various
and peculiar shapes. can be worked with one and the same apparatus, many articles
can be heated at the same time, large bars or blanks may be quickly heated
although the current used may be weak on account of the great amount of heat
that may be stored before the work is subjected, and an expert operator is not
required.
In the accompanying drawings,
Figs. 1 and
invention,
are sectional and plan views of apparatus for practising my
Fig. 3 is a slight modification of Fig. 2, and
Fig. 4 shows an apparatus adapted for welding and working purposes.
Referring specifically to the drawings, A represents a yielding bed of suitable
conducting or semi-conducting material, as powdered or granulated carbon, coal or
metal, or metal mixed with carbon or other semi or non-conducting material as fire-
brick, sand, or pumicestone, to obtain the resistance required. The said bed is preferably
supported in a box B of non-conducting material as fire-brick or asbestos. Within
and at each end of the box and facing each other are conducting plates CC of
metal or other material which form the terminals of an electric circuit and between
which the yielding bed is located. Extending from the plates C C and through
the brick are binding posts c c to which the electric conductors D D leading from a
suitable source of electricity are connected. E E E indicate the bars or blanks of
various shapes and sizes, with their ends embedded in the yielding material to be heated,
preparatory to being worked or operated as desired.
In order to prevent the plates, CC from becoming highly heated, the yielding bed
or resisting material is so formed as to be of higher conductivity where it is in contact
with the plates, or its cross section at the plates is larger than its cross section in the
middle where it is heated and the work embedded. To locate the heat produced by
the current passing through the low conducting material more particularly at the
centre of the box and not at its ends, without making the surface of the yielding
material lower in the middle, I form the box as shown in Fig. 3 with ends of much
greater cross section than the middle.
In Fig. 4 the apparatus described is arranged and supported between a stationary
and a movable clamp, similar to those usually employed in electric welding to hold the
bars to be welded, to illustrate that bars or blanks can be held in a suitable position
to be welded or worked, while heated by any method, and after they are sufficiently
heated or softened they can be welded or worked in any desired manner before being
removed from the box. The figure shows bars E E held by clamps F and F¹ with
their ends in contact and embedded in the yielding material A and in position to be
welded. After said bars are softened sufficiently, the weld may be effected by moving

page_text: clamp F¹ by means of the screw toward the other clamp, after which the bars may be
removed. It will be obvious that should it be necessary to cool the work more or less
before removing it from the apparatus, it may be done by discontinuing the current.
With this apparatus bars of very different conductivity and cross-section can be united
with ease and without burning the smaller bar, as the larger one may be exposed or
embedded a longer time than the smaller one.
In the last figure the plates CC lie flat upon the bottom of the box and the yielding
material is piled up in the centre of the box, leaving the ends uncovered to permit the
bars to be passed through easily.
In order to increase the resistance of the yielding material at the joint, a block of
non-conducting material as fire-brick may be placed between the plates upon the
bottom of the box as shown in dotted lines in the figure.
For the purpose of confining or retaining the heat, a cover of non-heat-con-
ducting material may be placed over the box B, as also shown in dotted lines in
Figure 4.
+
It will be obvious that the yielding bed may be of any suitable material that will
give the desired resistance to the current and in which material to be worked, can be
embedded and may be a liquid, as oil or a metallic liquid.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is:
1. The herein described method for electrically heating bars or blanks for welding and
working purposes, consisting in embedding the bars or blanks in a yielding bed of
conducting material, passing a heavy electric current through said bed to heat the
same, and then applying a force to weld or shape the said bars or blanks while
heated.
2. The herein described method for electrically heating bars or blanks for welding
and working purposes, consisting in passing an electric heating current through a
yielding bed of conducting material, then einbedding the bars or blanks therein to
heat or soften them, and then applying a suitable force to weld or shape the said bars
or blanks while in a softened condition.
3. The herein described method for electrically heating bars or blanks for welding
and working purposes, consisting in embedding the bars or blanks in a yielding bed
of low conducting material located between electric terminals and supported upon
non-conducting material, passing an electric current through said bed between the
terminals to heat or soften the bars or blanks embedded therein, and then applying a
suitable force to weld or shape the bars or blanks as desired.
4. The herein described method for electrically heating bars or blanks for welding
and working purposes, consisting in embedding the bars or blanks in a suitable
position in a yielding bed of low conducting material located between electric
terminals, passing an electric current through said bed, between the terminals to heat
or soften the bars or blanks embedded therein, and then applying a suitable force to
perform the operation desired upon the bars or blanks while in position.
5. The herein described method for electrically heating bars or blanks for welding
and working purposes, consisting in embedding the bars or blanks in a bed of
powdered or granulated conducting material located between electric terminals,
passing an electric current through said bed to heat the same and the bars or blanks,
and then applying a suitable force to perform the operation desired upon the bars or
blanks while in position.
6. The herein described method of electrically heating bars or blanks for welding or
working purposes, consisting in embedding a portion of a bar or blank in a yielding bed of
conducting material located between electric terminals while the other portion is not
embedded, and passing an electric current through said bed to heat the same and the
portion of the bar or blank embedded.
7. The herein described method for electrically heating bars or blanks for welding
or working purposes, consisting in passing an electric current through a yielding bed

page_text: of powdered or granulated semi conducting material located. between the electric
terminals, then embedding the bars or blanks therein until sufficiently heated, and
removing them without interrupting the current through the bed.
8. The herein described method for electrically heating bars or blanks for welding
and working purposes, consisting in embedding the bars or blanks in a yielding bed
of conducting material shaping said bed to create an uniform resistance to the current,
supporting the bed in a non-conducting receptacle, and passing a heavy electric current
through said bed to heat the same.
9. The herein described method for electrically heating bars or blanks for welding
or working purposes, consisting in first passing an electric current through a yielding
bed of conducting material until it is heated, and then embedding the work in said
material until it has reached the desired temperature.
O day of August 100
MARK WESLEY DEWEY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.