Electric Soldering Irons.
Year: 1890

page_text: Date of Application, 5th June, 1890-Accepted, 5th July, 1890
COMPLETE SPECIFICATION.
Electric Soldering Irons.
I, WILLARD M. MINER of Plainfield in the County of Union and State of New
Jersey in the United States of America, Electrician, 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:-
The invention has reference to electric soldering irons. Its object is the provision
of means whereby a soldering iron may be heated by electricity, and when so
heated to retain its heat for a considerable time. Simplicity of construction is
another feature of my invention.
In general, the invention consists of the usual solid head of copper, in combination
with a
heating resistance placed on the outside and surrounding the same. A shell
of non-heat-conducting material is placed over the resistance to concentrate the heat
upon the copper and to prevent its dissipation.
The invention will be described with reference to the accompanying drawings,
in which,
Fig. 1 is a longitudinal section of my improved soldering iron; and
Figs. 2 and 3 are respectively longitudinal and cross sectional views of modifications
of the same.
A represents the copper head, and B the handle, common to all soldering irons.
Beginning a little back of the point the head is cut away for some distance, and
around this contracted portion is coiled a German silver wire a. The diameter of the
coil is somewhat larger than that of the head, so that the two will not touch when they
are concentric. In forming the reduced portion of the head A shoulder b is left upon
which a thread may be cut to receive shell (). This shell may be made of brass, com-
pressed asbestos, or any other material. If of metal, it should be provided with a
lining c, of non-conducting material. This shell is closed at its inner end by a disk c',
of insulating material, and this is held in place by a washer c² and nut c³, the latter
working upon the threaded shank of the head, which extends back into a metallic
socket, forming part of the handle B. One end of the coil of wire a is in contact
with the copper head at the shoulder b, and the other end may be connected in any
suitable manner with one side of a source of electricity M, the circuit being complete
from the other side to some portion of the copper head, as shown. Although the
circnit wires are represented by finer lines than the coil, it is to be understood that the
resistance of the coil is higher than that of the line.
In figs. 2 and 3 I show modifications of my invention. In fig. 2 the coil is
substituted by a carbon cylinder I, and it is to be understood that I may usc.any kind
or form of resistance without departing from the spirit of any invention, so long as I
place such a resistance on the outside of the copper head. I may use a series of
carbon rods, a net work of wire, or any similar material or construction. In fig. 3, I
have shown the head or the contracted portion of it surrounded by a jacket J, of lime
or other heat retaining and refractory material. This will be found also to reduce the
current necessary to operate the iron.
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 combination, with a soldering iron, of a heating resistance included in an
electric circuit, said resistance being located on the outside of the bead of the iron for
the purpose set forth.
2. The combination, with a soldering iron. of a heating resistance included in

page_text: an electric circuit, said resistance being located on the outside of the head of the
iron and surrounding the same, for the purpose set forth.
3. The combination, with a soldering iron, of a heating resistance included in an
electric circuit, said resistance surrounding the head of the iron, and a shell for
confining the heat inclosing the resistance and the head of the iron.
1. A soldering iron having a head provided with a reduced portion or shank which
is surrounded by a heating resistance included in an electric circuit, and a shell placed
around the reduced portion to retain the heat and impart to the head a symmetrical
appearance.
5. The combination, with the head of a soldering iron having a coating of heat
retaining material, of a heating resistance included in the electric circuit surrounding
the same.
6. The combination, with the soldering iron, of a coil of wire forming a heating
resistance and surrounding the head thereof.
thi ath love of Tunn 1890
S. S. BROMHEAD,
97, Newgate Street, London, Patent Agent.