DETONATEUR A PROXIMITE POUR PROJECTILE

PROXIMITY FUSE ARRANGEMENT FOR A PROJECTILE

Abrégé anglais

ABSTRACT
A detachable proximity fuse adaptor for use with
the projectile having a percussion nose fuse. The adaptor
contains a proximity sensor, its control circuit board and
an electrical pressurized-gas capsule. Power for the
proximity sensor is provided by an electrolyte battery which
consists of a spaced electrode stack and an electrolyte
container. When the projectile is fired the resulting
forces move the electrode stack into the electrolyte container
thereby providing the necessary power for the proximity sensor.
When the sensor detects a target it ignites the pressurized-gas
capsule which, in turn, depresses the actuator member of the
conventional proximity fuse on the projectile. This adaptor
provides an economical solution to the problem of providing
proximity fuses when required on projectiles by using
projectiles already provided with less expensive percussion
fuses.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A detachable proximity fuse adaptor for use with a
projectile (10) having a nose fuse (11) actuated by impact of
an actuator member (13) on a target, comprising:
a detachable housing (21);
means securing said housing (21) on said nose fuse
(11);
said housing containing: a proximity sensor (22) for
sensing the proximity of a target, a control circuit (23)
actuated by said proximity sensor (22) in the proximity of a
target, an electrolyte battery (25,26) connected to said
control circuit (23);
a pressurised gas capsule (27) actuated by said
control circuit (23) in the proximity of a target;
said pressurised gas capsule (27) being located
adjacent said actuator member (13), whereby on detonation it
actuates said actuator member (13).
2. A proximity fuse adaptor according to claim 1 wherein
said electrolyte battery has an electrode stack and an
electrolyte housing, the electrode stack being immersed in the
electrolyte only on the firing of the projectile.
3. A proximity fuse adaptor according to claim 2, wherein
the section of the detachable housing containing the
electrolyte housing has limited displacement along the axis of
the adaptor.

Description

This application relates to a detachable proxiMity
fuse adaptor for use with a projectile equipped with a
conventional percussion nose fuse.
Proximity fuses using electronic or optical sensing
and having various safety features are well kno~"n. They are
constructed as integrated fuse units and manufactured for use
with trench mortar shells, artillery shells or rocket
projectiles. Due to the expense of the electronic components
such fuse units are significantly more expensive than conventional
percussion nose fuses of a mechanical nature which do not
provide proximity sensing. In proximity sensing in the range
between 2 and 12 m there has been no economical alternative
to such expensive proximity fuses.
The invention relates to a detachable proximity fuse
adaptor for use with a projectile having a nose fuse actuated
by impact of an actuator member on a target, comprising: a
detachable housing, means securing the housing on the nose
fuse, the housing containing a prox~mity sensor, an electrical
fuse capsule, a control circuit and a source of electrical
power connected to the control circuit; the electrical fuse
capsule being located adjacent the actuator member whereby on
detonation it actuates the actuator memberO
The invention has the advantage that a projectile with
a conventional percussion nose fuse can be thus transformed
into a proximity fuse projectile by attaching the adaptor in the
field. The resulting assembly is economical in that the more
~xpensive electronic components are only used when necessary
to obtain the proximi-ty function. The adaptor is short and of
light ~eight so that the ballistics of the projectiles are not
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3~.~
affected.
A detailed example of the proximity fuse adaptor of
this invention will now be described in conjunction with the
accompanying drawing which shows a longitudinal section of a
projectile, such as a shell, having a percussion fuse and with
the proximity fuse adaptor secured thereto.
The drawing shows a projectile body 10 containing a
percussion nose fuse 11 of known type in which an actuator
member 13 drives the firing pin into the detonator on impact
on a target when it is not blocked by switching member 12.
The present invention relates to a detachable proximity
Euse contained in an adaptor 20, the adaptor beinq mechanically
connectea to the nose fuse 11 itself threadably attached to
projectile 10. Proximity fuse adaptor 20 consists of a housing
21 containing, in order from top to bottom, a sensor 22, its
electronic control circuit board 23, an electrode stack 25
with an upwardly extending terminal 2~ and housing 26 containing
electrolyte, and a pressurized-gas capsule 27. The electrode
stack 25 and the electroly-te housing 26 function as an
electrolyte battery when the stack is immersed in the
electrolyte. The pressurized-gas capsule functions as an
electrical detonator when energized.
The base of the adaptor is attached to fuse 11 by three
pins 28 equally spaced around the perimeter of the fuse which
engage corresponding recesses 29 formed in the adaptor housing
21 to provide a bayonet-type fastening. This attachment holds
a ring-shaped bearing surface 30 of housing 21 abutting on the
curved surface of fuse ]1.
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`s ~ 3;2~-~
The section 31 of the housing, which includes the
electrolyte container 26 and -the pressurized-gas capsule 27
is movable along the axis of housing 21 with the displacernent
llmited by engagement of the ends of recess 32 with a pin 33
extending inwardly from the adaptor housing. A further ring-
shaped bearing surface 35 provided on section 31 engages the
head of fuse 11 when -the adaptor is connected to the projectile
providing further support and ensuring that electrolyte
container 26 is in proximity to electrode stack 25.
The operation of the proximity fuse adaptor is now
set out. When the need for a proxim7ty fuse arises, for
example in the field, adaptor 20 is attached to nose fuse 11
of a projectile 10 by means of the bayonet-type fastening.
On firing of the projectile, the electrode stack 25 is forced
towards electrolyte housing 26 and, when a predetermined force
is exceeded, breaks the lld of the housing and immerses the
electrodes in the electrolyteO Thus, the battery is activated.
A gasket ~4 is provided to ensure that the electrolyte does
not flow into the space previously occupied by the electrode
stack. Thus, after a cer-tain time voltage is applied to
energize circuit board 23 and proximity detector 22. The
connection to these elements is provided from terminal 24
and a suitably isolated contact ring. Such proximity sensors
are shown in German Patent Publications 2,608,066, 2,456,162
and 2,949,521. When the projectile reaches a predetermined
distance from the target this is sensed by detector 22 and
pressurized-gas capsule 27 ignited via terminal pairs 41,42
and 43,44. This, in turn, depresses the actuator member 13 of
the nose fuse thereby actuating the firing pin 14.
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The feature that section 31 is movable in adaptor
housing 21 ensures safety during handling and transportation.
That is, electrolyte housing 26 resists downward movement of
electrode stack 25 only after the electrode assembly has been
assembled on the nose fuse of a shell. Even once it is in
this position sufficient force to rupture diaphragm 36 is
still necessary before the battery is activated.
Thus, there has been described a detachable proximity
fuse adaptor which can be used with a projectile having a
conventional percussion nose fuse.
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Dessin représentatif