Improvements in Submarine Mines.
Year: 1897

page_text: Improvements in Submarine Mines.
I, PETER CHRISTIAN FRIEDRICH HOFFMANN, of 7, Wilhelmsplatz, Kiel (Hol-
stein) in the Empire of Germany, Agent, do hereby declaro the nature of this
invention to be as follows:-
This invention relates to electric submarine mines.
The casing of this improved submarine mine which may be balloon-shaped has
a number of openings provided upon its upper part, which openings are covered
by elastic caps which latter are traversed by contact pins. In the interior of the
casing a contact plate lies opposite each contact pin; this contact plate being
supported by a curved bracket or cup. Each pair of contact pins and contact
plates are connected by clectric conductors to a source of electricity.
In the interior of the mine-casing a drop-contact body, presenting, for ex-
ample, the shape of a sphere is arranged, which under ordinary circumstances
rests in a fixed cup-shaped receptacle. This latter is located in a second cup
from which it is insulated, and both of these cups are electrically connected by
suitable conductors.
A separate conductor leads to the priming composition of the mine.
If the top surface of the above described submarine mine be struck by a vessel,
any one of the contact pins will be pressed against its appertaining contact plate
and the electric circuit thus closed, whereby at the outlook-station a signal is
given. From the latter station then through the medium of the conductor the
mine can be exploded.
If, on the other hand, an attempt be made of fishing out the mine and of
rendering the same ineffective by carrying it away with the conducting cable or
with the mooring cable or attachment, then the mine-casing becomes inclined,
the drop-contact falls on to the exterior cup and thus electrically connects the
latter with the interior cup. In this case the circuit is likewise closed and
thereby a signal given at the look-out-station.
Thus the operation of rendering the mine ineffective by carrying the same
away is rendered very difficult and practically impossible.
Dated this and day of December 1907

page_text: invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
The present invention relates to improvements in submarine mines particularly
of that class in which the outer casing of the mine is provided with a plurality
of contact devices adapted to close an electric alarm circuit in order to give a
signal at a proper station connected with the said contact devices of the mine by
means of suitable conductors.
The object of the said invention is to provide means whereby the fishing out of
the mine and carrying it away or making it otherwise in-effective is rendered prac-
cally impossible; and with this end in view my invention consists of a suitable
contact device or contact devices arranged in the interior of the mine and adapted
to close automatically the said alarm circuit of the mine as soon as the mine, in
the operation of making it ineffective, is brought out of its normal upright posi-
tion.
In order that my invention may be more fully understood by those skilled in
the art to which it appertains, I will now proceed to describe the same in detail
and for that purpose will refer to the accompanying drawing, which shows a
vertical section of my improved submarine mine.
The casing of the improved submarine mine which may be balloon-shaped or
of any other suitable form, has a number of openings provided in its upper part,
and when necessary also in its sale parts, which openings are covered by elastic
caps which latter are traversed by contact pins b' attached to the said elastic
caps a¹
In the interior of the casing a contact plate lies opposite each contact 6,
this contact plate 65 being supported by a curved bracket or cup a². Each pair
of contact pins b' and contact plates 6 are connected by electric branch con-
ductors cc to main conductors gg in the circuit of which are placed at the
observing station a source of electricity and a suitable alarm device.
In the interior of the mine casing a drop-contact body &, presenting, for
oxample, the shape of a sphere is arranged, which under ordinary circumstances
rests m a fixed cup-shaped receptacle e. This latter is located in a second cup e
from which it is insulated, and both of theso cups are also electrically connected
by suitable conducting wires with the main conductors 99 respectively.
Separate conductors or wires f lead to 'the primer or priming composition of
the mine; outside the mine casing these wires f may be wound together or other-
wise connected with the wires g of the alarni circuit so as to form one single
cable y comprising four separate conductors.
If the top surface of the above described submarine mine be struck by a
vessel or the like, one of the contact pius b' will be pressed against its apper-
taining contact plate and the electric alarm circuit thus closed, whereby at
the outlook-station a signal is given. From the latter station then through the
medium of the priming conductor circuit the mine may be exploded.
If, on the other hand, an attempt be made to fish out the mine and to render
the same ineffective by carrying or dragging it away by means of a hook or the
like attached to the conducting cable g or to the mooring cable or anchor chain,
then the mine-casing becomes inclined, the drop-contact & falls to the exterior
cup and thus electrically connects the latter with the interior cup e. In this
case the alarm circuit is likewise closed and theroby a signal given at the look-
out or observing station.
Thus the operation of rendering the mine ineffective by carrying the same
away is rendered very difficult and practically impossible.
As many changes might be made in the construction and relative arrangement
of the different parts without involving a departure from the gist of my inven-
tion, I would have it understood that I do not limit myself to the exact con-
struction shown and described but consider myself at liberty to make such
changes and alterations as fall within the scope of my invention.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a submarine mine the combination of an electric alarm circuit of an
observing station with a contact device or contact devices arranged in the interior
of the mine casing and adapted to close automatically the said alarm circuit,
when the mine is brought out of its normal position, substantially as and for
the purpose set forth.
2. In a submarine mine the combination of a plurality of external contact
devices provided on and in the walls of the mine casing and adapted to close an
electric alarm circuit of an observing station, with a contact device or contact
devices arranged in the interior of the mine and adapted to close automatically
the said alarm circuit as soon as the mine is inclined or brought out of its
normal position, substantially as and for the purpose set forth.
3. In a submarine mine the combination of a plurality of external contact
devices (a' b¹³ 63), of an interior drop-contact device or devices (de) and of an
electric alarm circuit being in electrical connection with an observing station and
with the contact pieces (b'e¹³) of the said contact devices, substantially as
specified with reference to the accompanying drawing.
DL
. . 1
a
1000
HASELTINE, LAKE & Co.,
46, Southampton Buildings, London, W.C., Agents for the Applicant