Improvements in Heating and Welding by Electricity.
Year: 1891

page_text: Date of Application, 1st Aug., 1891
Complete Specification Left, 30th Apr., 1892-Accepted, 11th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Heating and Welding by Electricity.
I, HENRY HOWARD, of Coomb's Wood Tube Works, Halesowen, near-
Birmingham, Manufacturer, do hereby declare the nature of this invention to be
as follows:
According to this invention I interpose in the circuit and in proximity to the.
work a block of carbon or other comparatively bad conductor of electricity which
by reason of its greater resistance becomes heated and thus heats the work by
radiation. The arrangement I adopt is as follows:-The positive pole of the
battery or other source of electricity is connected to a block of carbon which may
rest upon or be partially surrounded by firebrick or similar material to increase the
radiation of the heat on one side of the work and is led from thence by a conductor.
to the work or to the support on which the work rests whilst the negative pole is.
connected to a pencil of carbon situated on the other side of the work an electric
arc being formed between the pencil and the work so that the work is heated on,
one side by the arc and on the other by radiation from the heated block.
The block of carbon acts as a resistance and in some cases therefore the:
regulating resistance usually employed in the circuit may be dispensed with.
Dated this 1st day of August 1891.
CARPMAEL & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in Heating and Welding by Electricity.
I, HENRY HOWARD, of Coomb's Wood Tube Works, Halesowen, near-
Birmingham, Manufacturer, 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 :-
According to this invention I interpose in the circuit and in proximity to the
work a block of carbon or other comparatively bad conductor of electricity which
by reason of its greater resistance becomes heated and thus heats the work by
radiation. The arrangement I adopt is as follows:-The positive pole of the
battery or other source of electricity is connected to a block of carbon which may
rest upon or be partially surrounded by firebrick or similar material to increase.
the radiation of the heat on one side of the work and is led from thence by a
conductor to the work or to the support on which the work rests whilst the negative.
pole is connected to a pencil of carbon situated on the other side of the work an
electric are being formed between the pencil and the work so that the work is.
heated on one side by the arc and on the other by radiation from the heated
block.
The block of carbon acts as a resistance and in some cases therefore the
regulating resistance usually employed in the circuit may be dispensed with.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan and Figure 2 a side elevation of the apparatus and Figures 3
and 4 are sections on the lines X X and Y Y Figures 1 and 2 respectively.
A is the conductor from the positive pole of the battery or other source of
electricity, the end of which is connected to the metal clip A' resting on the
insulating block A². The other end of this clip is furnished with jaws in which.

page_text: a rod B of carbon is held the jaws being tightened on the carbon by the screw A'.
The other end of the carbon rod B is held in a similar clip C₁ at the end of the
metal bar C. D' is a conductor connecting the bar C to the work D or to the
support E on which the work rests. F is a jacket of asbestos or other refractory
insulating materially partially surrounding the carbon rod B. The carbon rod B
should be placed as near as is practicable to the work but care must be taken that
the current is not short circuited by forming an arc between the rod B and
the work.
The length and sectional area of the rod B must be properly proportioned to
the current being employed, if too large the rod will not become properly heated,
whilst if too small it will become overheated and destroyed. A suitable current
for a rod 15 millimetres in diameter and 200 millimetres long would be about
70 volts and 300 amperes.
The negative pole of the battery or other source of electricity is connected by a
conductor to the carbon pencil G.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein described method of heating and welding by the electric arc
in which the work forms one pole and a pencil the other pole consisting in
heating the work by radiation from a resistance interposed in the conductor
leading from the source of electricity to the work or to the support on which the
work rests.
2. In apparatus for heating aud welding by the electric arc where the work
forms one pole and a pencil the other pole, the combination of a conductor leading
from the positive pole of the source of electricity, a resistance in the said conductor
situated on one side of the work, a conductor leading from this resistance to the
work or to the support on which the work rests and a pencil connected by a
conductor to the negative pole of the source of electricity.
3. In apparatus for heating and welding by the electric arc where the work
forms one pole and a pencil the other pole, the combination of a conductor leading
from the positive pole of the source of electricity, a metal clip connected to the
conductor, a carbon rod one end of which is held in the clip, a second clip holding
the other end of the carbon rod, a conductor connecting the second clip to the
work or to the support on which the work rests and a pencil connected by a
conductor to the negative pole of the source of electricity.
4. Apparatus substantially as described and shown in the drawings.
Dated this 25th day of Anril 1809
HENRY HOWARD.