Improvements in Apparatus Used in connection with Submarine Mines.
Year: 1896

page_text: Date of Application, 18th Jan., 1896
Complete Specification Left, 19th Oct., 1896-Accepted, 21st Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus Used in connection with Submarine
Mines.
We CHARLES AMBROSE M°Evor of 69 Victoria Street, Westminster,
Engineer and SIEMENS BROTHERS AND COMPANY LIMITED of 12 Queen Anne's
Gate, Westminster Electrical Engineers do hereby declare the nature of this
invention to be as follows:-
We ensure that a contact made for sending a firing current to a fuse shall remain
until the firing current ceases. In the connection between the end of the cable
passing to each mine and the fuse of the mine we interpose an electro magnet of
high resistance. The armature of this magnet is held away from the magnet by a
spring of sufficient strength to allow of test currents being passed through without
the armature being attracted, but when a stronger battery is used and the mine is
to be fired, the armature is attracted and causes a second armature carried by the
spring to be brought against the core of a second electro magnet and complete the
battery circuit through the coils of this second magnet which are of low resistance;
the full strength of the battery is thus passed to the fuse, and the contact remains
good so long as the firing current passes.
The same result is effected if the spring carrying the armatures be depressed
on the mine being struck by a passing vessel by the action of a suspended swinging
weight.
In this case a weak battery current is kept continually passing through the high
resistance electro magnet coil or coils on the mine. When the spring is depressed
by the rocking of the suspended weight these high resistance coils are short
circuited and the current passes through the low resistance magnet coil. The
increase in current may be used either to give a signal on shore or to switch in the
stronger battery or both.
The rocking weight is carried by an arm which at its upper end passes through
an opening in a fixed bar to which it is held up by a spring bearing against a nut
on the upper end of the arm, the position of the nut determining the freedom with
which the weight can rock.
The bottom of the weight comes in contact with a plate on the spring carrying
the armature which is thus depressed when the weight is rocked. The armature
of the high resistance magnet is supported in brackets on the spring into which it
is slidden and it is secured in place by a screw passing through a hole in it into the
plate on the spring.
The armature can thus be removed if thought desirable so that the passage of
a current through the high resistance magnet shall not effect the firing of the fuse,
so that the same circuit closing apparatus may be arranged to fire the fuse either
by contact or by observation.
Dated this 18th day of January 1896.
C. A. MCEVOY.
SIEMENS BROS. & CO., LIMITED.
ALFRED SABINE,
Secretary.

page_text: The increase in current may be used either to give a signal on shore or to switch in
the stronger battery or both.
The rocking weight T is carried by an arm T₁ which at its upper end passes
through an opening in a fixed casting U to which it is held up by a spring T2-
bearing against a nut T on the upper end of the arm T¹ the position of the nut
determining the freedom with which the weight can rock. The bottom of the weight
which is adjustable by a screw as shown comes in contact with a plate V on the spring J
carrying the armatures which is thus depressed when the weight is rocked. The
armature of the high resistance magnet H is secured to the spring J by nuts and it
can be removed if thought desirable so that the passage of a current through the
high resistance magnet shall not effect the firing of the fuse so that the same-
circuit closing apparatus may be arranged to fire the fuse either by contact or by
observation.
It is preferred that when the iron armature has been removed it should be re-
placed by a brass armature, so as not to alter the conditions of weight, adjustment
and balance of the spring.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The improved contact maker having two electro-magnets, whose armatures are
connected together one magnet being of high resistance and through which the
circuit can always be closed whilst the other is of low resistance and through which
the circuit can be closed only when the armature has been moved or otherwise
displaced by the first magnet.
2. The combination with the subject matter of the preceding claim of a suspended.
weight the oscillation of which displaces the armature.
3. Contact makers substantially as described and shown in the drawings.
ليمي
1
1000
C. A. MCEVOY.