Apparatus for Protecting Electric Installations for Telegraphic, Telephonic, and Lighting Purposes from the Effects of Lightning or Discharges of Atmospheric Electricity.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Apparatus for Protecting Electric Installations for Telegraphic,
Telephonic, and Lighting Purposes from the Effects of Lightning
or Discharges of Atmospheric Electricity.
I, GEORGE WILLIAM SPITTLE of Campos, Rio de Janeiro, Republic of Brazil,
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:-
My invention relates to apparatus for protecting electric installations, as also the
persons operating the same at times when the conductors &c. are liable to receive
discharges of atmospheric electricity during thunder storms.
In order that my said invention may be readily understood I will proceed to
describe the same with reference to the accompanying drawings, in which Fig. 1
shews an elevation of the apparatus fixed within a varnished wood casing having a
glass cover. Figs. 2 and 3 shew cross sections, and Fig. 4 a plan. Two wires A
and B communicate respectively with the apparatus to be protected and with the
line wire.
The wire A forms the coil of an electro-magnet C, the end D being connected
to a support E carrying a contact screw F. G is an armature in contact with the
said screw, and turning on pivots at d d', from which a wire I passes to the electro-
magnet L the coil of which is connected to wire B.
The current from the electric generator thus passes through the electromagnet C
the wire D the support E the regulating screw F the armature G the support H
wire I electromagnet L and passes away through wire B.
The support E carries the screw F which regulates the distance of the armature G
from the electromagnet L.
The armature G is formed of a bar of non-magnetic conducting metal from a to a',
and of soft iron from to b. The distance of the armature G from the electro
magnet L, regulated by the screw F is so arranged that the electro-magnet cannot
attract it, when excited by the normal current, but only when a stronger current is
passing, in which case the armature assumes the dotted position c c¹. The screw M
which is carried by the support O and which communicates with the earth wire N
is adjusted to a distance of from 1 to 1 millimetres from the armature.
The ends of the screws F and M are of platinum, and the part of the armature
which comes in contact therewith is also coated with platinum, in order to prevent
the fusion of these parts in the case of the formation of an electric arc by the
displacement of the armature in consequence of the passage of a discharge of
atmospheric electricity.
The armature G is supported by two screws points d d' carried by a bracket H
as shewn at Fig. 3.
When a discharge of atmospheric electricity into the line wire takes place, the
electro magnet L attracts the armature G thereby putting it at once in com-
munication with the screw M which is connected to earth at N, the armature
assuming the position c c' and being thus entirely insulated from the apparatus to
be protected.
At the moment of discharge, the current passes through the electro-magnet L,
wire I, bracket H, armature G, and screw M to earth. Immediately after the
discharge, the attraction of the electromagnet L ceases, and the armature owing to
the preponderance of the left hand end, falls back into its original position, making
contact with screw F, and this closes the circuit of the apparatus again. The soft
iron core S of the electromagnet C has its end flattened as shewn at Fig. 2, and

page_text: constitutes the pole of the electromagnet, which by means of its magnetic field
extinguishes the electric are when this tends to form.
When the above described apparatus is employed for protecting telephonic and
telegraphic apparatus the electromagnet C can be omitted, the wire D being in that
case led directly to the apparatus to be protected.
The size of the apparatus and thickness of the wires will vary according to the
instruments or installation which it has to protect.
The above described apparatus possesses the advantage, over all apparatus hereto-
fore employed for the purpose, of great simplicity of construction and operation,
and the absence of the necessity of cleansing it after each discharge, or of replacing
any of its parts.
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 :-
:-
Apparatus for protecting electric installations from discharges of atmospheric
electricity, consisting of the combination of an electromagnet connected with the
line wire, a pivotted armature, in conducting connection, with the electromagnet, a
screw contact connected with the instrument or machine to be protected, and a
second screw contact connected with earth, the said parts being so arranged, that
under normal working the armature is removed from the electro magnet and makes
contact with the screw for completing the circuit of the instrument or machine, but
when a discharge of atmospheric electricity takes place, this in passing through the
electromagnet causes it to attract the armature which is thereby made to break the
circuit of the instrument and to make contact with the earth screw, substantially as
described.
Dated this 214th dow of Avust 1901
ABEL & IMRAY,
Agents for Applicant.