Note: Descriptions are shown in the official language in which they were submitted.
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BAC~GROUND OF THE INVENTION
The present invention relates to a new and improved
construction of fuse for a spinning projectile comprising an
electromagnetic ignition cur~ent generator and a fuse chain for
exploding an explosive charge of the spinning projectile, the
ignition current generator incor~oratirig a coil armature.
With a state-of-the-art fuse of this type the fuse chain
is arranged in axial d;rection after the ignition current generator.
A drawback of this prior art construction resides in t.he Eact that
the fuse chain and the ignition current generator require a great
deal of space, which then is no longer available for further fuse .
components or for the explosive charge.
SUMMARY OF THE INV~TION .
Hence, it is a primary object of the present invention
to provide a new and improved c.onstruction of fuse for a spinning
projectile which is not associated ~ith.the aformentioned draw~
backs and limitations of the pr;.or art proposals. ~
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Another and more specific object of the present inven-
tion aims at the provision of a fu~e or fuse arrangement for a
2a projectile wherein the fuse chain and the ignition current generator
occupy a smaller amount of space.
The above objects are met by th.e present invention ; .
which provides a fuse arrangement for a spinning projectile,
comprising an electromagnet ignition current generator and a fuse :: :
chain for e.xploding an e.xplosive charge of the spinn~ng projecti.le,
the ignition current generator ~eing provided with a coil armature,
the coil armature hav;ng a b.ore, the fuse chain including at least
one component arranged in the bore of the coil armature.
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Now in order to lmplement the e and still further
objects of the invention, which will become more readily apparent
as the description proceeds, the fuse of this development is
manifested by the features that at least a part o the fuse chain
is arranged in a bore in the coil armature.
BRIEF DESCRIPTION OF THE DRAWINGS
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The invention will be better understood and objects
other -than those set forth above, will become apparent when con-
sideration is given to the following.detailed description thereof.
Such description makes reference tq the annexed drawings wherein~
. Figure 1 is a fragmentary longitudinal sectional view
through a projectile fuse or fuse arrangement incorporating an
electromagnetic ignition current generator and constructed accord-
ing to a first exemplary em~odiment of the invention;
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. Figure 2 is a cross-sectional view taken substantially
along the line II-II of Figure l;
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Figure 3 is a fragmentary seetional view, similar to the
showing of Flgure 1, of a second exemplary embqdiment of the
invention; and
. Figure 4 is a cross-sec~ al view taken substantially
along ~he line IY-IV of Figure 3.
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DETAILED DESCRIPTION OF THE INVENTION
Describing now the drawings, it`is to be understood that
only enough of the projectile structure has been shown in order
to enable those skilled in the art to readily understand the
ba~ic concepts of the invention. Turning attention to Figure 1
wherein there is illustrated a preferred constructional embodi-
ment of fuse for a spinning projectile it will be seen that such
fuse embodies a fuse housing 1 consisting of a front housing
portion 2 and a rear housing portion 3, these two housing por-
tions 2 and 3 being t~readably interconnected with one another by
means of the threaded screws or bolts 14, 16 or equivalent structu
The fuse of fuse arrangement of this development is located in a
blindhole bore 4 at a tail or rear portion 5 of the projectile and
bears against the base or bottom of such tail portion. This
b1indhole bore 4 i9 substantially concentrically arranged with
respect to the lengthwise axis of the projectile, and which
projectile is generally indicated by reference character 100.
In a central bore 6 of the rear housing portion 3 there are
arranged two fuse elements which have been shown in broken or ::
phantom lines, namely a current storage 7 and an electronic con-
trol means ~. The housing portion 3 possesses a cover or cover
member 9 with a forwardly protr~ding cylindrical projection 10 in
which there is centered the front or forward housing portion 2.
The front housing portion 2 possesses a groove 11 in the central ::.
plane of which there i9 located the fuse axis, Arranged in the
groove.ll is a double-pole armature 12 ~Figure 2) which incor- :
porates a substantially hollow cylindrical central amature portion
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or part 13 having a floor or base 13a which bears upon a recess 9
in the housing cover 9 and which recess is located substantially
concentrically with respect to the fuse axis. The front housing
portion 2 bears under the pressure of screws 14 or the like
against an end face of the armature portion 13, so that the arma-
ture 12 is force-lockingly connected with the fuse housing 1.
Two arms or arm members 15 which extend outwardly from the central
armature portisn or part 13 bear upon the projection 10 of the
rear housing portion 3. TWD windings or coils 16 are arranged
upon the arms 15. In a b~re 13k in the armature portion 13 there
is arranged a firing element 17, such as a detonator cap, con-
stituting part of a fuse chain of the fuse. The firing element
17 contained in a jacke~ or shell includes an.electrically
ignitable flame-generating firing means, generally indicated by
reference character 17'. A contact pin 18 of the firing element
17 piercingly extends through a bore in the floor or base 13a of
the armature portion 13 into ~ plug component or part 19 which is
arranged in the bore 6 of the rear housing 3 and engages in a bore
of the housing cover 9. The plug 19 is connected in not particu-
larly illustrated manner with the current storage 7, which
typically may be constituted by an electrical storage capacitor.
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. The front end face of the front housing portion 2
possesses a recess 20a in Which there is rotatably mounted a
rotor 20. The axls of the rotor 20 i9 disposed essentially
parallel to the lengthwi~e axis of the pro~ectile I00. The rotor
20 possesses an eccentric bore 21 in which there iq arranged a
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, detonator 22 froming a part of the fuse chain. In the so-called
. , .armed or live position of the rotor 20 the axis of the bore 21
. coincides with the fuse axis. The charge of the detonator can
' . be exploded by the flame action of the firing element 17. The
groove 11 is in spatial c~nnection through the agency of the bores
. . 23, 24 in the housing 1 and in the rotor 20 with the bore 21 con-
taining the detonator 22.
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., A cover member 25 closes t~e front end of the fuse
housing 1. By means of a threaded disk or plate 102 or equivalent
fastening expedient, and which disk 102 is threadably connected
ith a threaded part 4a of the bore 4 o`f the tail portion 5, it is
ossible to fixedly retain the fuse in the bo,re 4 of the tail or
. ear portion 5. A capsule or detonator 27 which contains a rein-
forcement charge, and which de~Q~ator 27 is concent'rically arranged '
. with respect to the fuse axis, forms the last element of the fuse
. chain of the fuse arrangement. The detonator 27 is secured in a
. bore 101 of the threaded disk 102, this detonator extending for-
wardly into an explosive charge 28 which is arranged in a pro-
. jectile body portion 29 also threadably connected with the tail. portion 5.
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. An annular or rin~=shaped double-pole field magnet 30 is
: arranged in an outer recess 31 af the fuse housing 1. This magnet
30 is fixedly connected wi,th à fir~s,t bearing race 32 of an axial
ball bearing and bears via ~he ball members ~3 upon a second bear-
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. ing race 34. The balls or ball members 33 are not separated from
, . one another by a cage, so that in order to obtain the requisite
load supportiny function of the bearing an appropriately large
. number of balls can be arranged. The supporting surface, by
means of which the magnet 30 and the first bearing race 32 which
is fixedly connected therewith bears against-the balls 33, has
been designated by reference character 39. The second bearing
racs'34 is ~eated against forwardly directed pr~truding or bulging
portions 36 of a ring member 35, these bulging or protruding por-
tions 3.6 being arranged at a uniform angular spacing from one
another. The ring or ring member 35 in.turn bears against a rear
. flank 37 of the annular groove or recess 31 which.is directed per-
. endicular to the fuse axis. In.the arrangement shown in Figure 1
. ~ l he magnet 30 has been illus~r~ajted in the transport position in
hich it is'held pressed by means, of its end face at a forward or : ,
ront flank 3B of the annular groove or recess 31 under the pressu~
. f the pre-biased projections or bulging-portions 36 of the ring
., nember 35.
- Having now had the benefit of the descriptio,n of the
first exemplary embodiment portrayed in Figures 1 and ~ its mode
of operation will be considered and is^as follows: By virtue of
the fact that the field magnet 30 in the transport position is
: ressed against the front flank, there is prevented that the
agnet 30 can rotate relative to the projectile prior to the fir-
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ing thexeof. When there appears the acceleration of the projectilupon the firing of such projectile then the bulging or protruding
portibns 36 of the ring member or ring 35 are compressed together
under the action of the inertia force applied at the magnet 30.
Conse~uently, magnet 30 is free, so that it does not experience
any rotational drive through the action of the fuse housing 1
which now rotates with the pro~ectile. The inner and outer jacket
surfaces of the magnet 30 and the race 32 are equally free in that
they possess a spacing both from the wall of the bore 4 as well
as also from the base or battom 31a of the annular or ring-shaped
groove 31. Due to the fact ~hat the magnet 30 is mounted at the
balls, upon iring of the projectilè, this magnet 30 under the
action of the inertia forae which is applied thereat automatically
assumes a i~table equilibrlum position in which it is centered
at the rear bearing race 3~ and maintains such position upon
passage of the projectile through the firing barrel of the weapon.
In this position the magnet 30 neither contact~ the tail or rear
portion 5 nor the fuse housing. Owing to its arrangement in the
ring-shaped groove or recess 31 of the fuse housing 1, in other
words at the largest possible diameter, this magnet 30 possesses
a large moment of inertia. By virtue of this large moment of
inertia of the magnet 30 and its mounting at a ~oller bearing,
during the acceleration phase of the projectile in the weapon
barrel ther occurs a largo relative rotational speed between the
magent 30 and the armatu~ coil arrangeme~t 12, 16.
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Since the detonator cap 17 is arranged within the bore
13b in ~he armature portion or part 13 there is achieved a
signficant saving in space which can be advantageously employed
for the arrangement of other fuse components or'the explosive
charge.
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Considering now the second ,exemplary embodiment as shown
in Figures 3 and 4 there will be recognized a fuse housing la
which is threaded into a rear portion of a projectile body 29a
and bears with its shoulder 42 at such projectile body. The fuse
housing la possesses an eccentric bore arrangement 43, 44 with '
regard to the lengthwise axis ~f the projectile and which bore
arrangement 43, 44 is stepped in diameter. In the narrow bore
portion 43 there is rotatably mounted a rotor 20b. In the other '
bore portion'44 there ~s in~erted a disk or plate 45 in which
there is threaded a de~onator or detonator cap 27' provided with ,
a reinforcement charge 27a. The detonator cap 27' with the re-
inforcement charge 27a extends into an explosive charge 28a
contained in the projectile body 29a. The reinforcement charge
27a is in spatial communication by means of a bore 46 with the
bore portion 43. A detonator 22a is inserted into a continuous
bore 21b of the rotor 20b, the spacing of the lengthwise axis of ,~
the detonator 22a from the rotor axis is equal to the spacing of
the rotor axis from the projectile axis. At its rear end the
fuse housing la possesses a bore arrangement 47, 48 which is
stepped in diameter. The front bor,e portion 47 opens into the
bore 43 contained in the rotor 20b and is separated by a shoulder
48a from the re~ b~X~ ~r~ion 48.
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A base piece or element 49 of the projectile bears by
means of a flange edge 50 at the fuse housing la and possesses a
substantially sleeve-shaped projection 51 which extends into the
, bore 48 and threaded with the fuse hous1ng la. Between the end
i face of the projection 5i and the shoulder 48a there i8 arranged
a substantially ring-shaped permanent magnet 30a. The base por-
tion or piece 49 possesses a central blindhole bore 52. In this ;
blindhole bore 52 there is a~ranged a ball 53 by means of which
there is supported at the base portion 49 a substantially cup-
shaped cage 55 by means of its pin or plug member 54. This cage
55 is provided at its forward edge with two diametrically oppo-
sitely situated cut-outs or recesses 55' in which there is secured
a support or carrier 56, as best seen by referring to Figure 4.
The support 56 is mounted by means of a sleeve-shaped projection
57 in the fuse housing la. The support 56 simultaneously forms
the armature core at which there is wound off-center a coil or
winding 58. Diametrically opposite the coil 5~ there is arranged
at the support 56-a piezoelectric crystal 59 at th~e base of a
bore 56' of the support 56 and which bore opens towards the rear
end face of such support. In this bore 56' there is further
arranged an insulating body 60 in which there is movably mounted
an inertia body 61 and bears at the pieæoelectric crystal 59. The
support 56 possesses a bore ~2 which is coaxially arranged with
respect ko the lengthwl~e axis of the projectile and in which
bore there is inserted a deto~ator cap 17a having a conventional
flame generating-firing means, again generally indicated by refer-
ence character 17'. The one pole of the electrical firing current
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circuit for the firing means, in this case the detonator cap 17a,
is connected to the body of the support 56 and the other pole ex-
tends in the form of a contact pin 18a into a control element 63
which is mounted in an insulating element or piece 64. Further-
more, in the cage 55 there are arranged in not particularly
illustrated manner a rectifier and a capaci~or constituting an
energy or current storage device, wherein the capacitor is connected
via a here not particularly illustrated control circuit with the
detonator cap 17a for controlling di~ferent operating conditions
of the fuse. Such arrangement has been disclosed in greater detail
in the commonly assigned, copending Canadian application Serial No.
226,100 filed May 2, 1975, entitled l'Projectile Fuse For a Spinning ~`
Proiectile Containing a Detonator Cap And An ~lectromagnetic Firing
Or Ignition Current Generator", listing as the inventor Walter
Hu'rlimann, one of the inventors of this application.
Having now had the benefit of the foregoing description
of the variant embodiment of projectile fuse for a spinning pro~
jectile as considered above with respect to Figures 3 and 4 there
will be now discussed its mode of operation which is as follows:
Prior to firing of the projectile the fuse chain or circuit consist-
ing of the detonator cap 17a, the detonator 22a and the cap with
the reinforcement charge 27a is interrupted in that the detonator ~-~
22a is located externally of the projectile axis. Upon firing
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of the projectile carrying the fuse the ball 53, owing to the load
of the inertia force applied ,at the cage'55, slightly penetrates
into the base piece or portion 49. As a result there is imparted
to the cage 55 its freedom of movement, so that it can rotate ~ ,
relative to the projectile. During the passage of the projectile
through the firing barrel of the weapon from which it is fired
the projectile is accelerated to a very high rotational speed.
Since at the plug or pin member 54 of the cage 55 a frictional
force engages at only a very s~all lever arm, this cage experience5 -''
a correspondingly small rotatipnal drive. The rotational speed
of the cage 55 is therefore only very small owing to the large
moment of inertia of its mass, so that the difference between the
rotational speed of the rotary magnet 30a which rotates with the
projectile and the cage 55 and which is important for the generat-
ion of the current is practically equal to the rotational speed
of the projectile. '-
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After the projecti,le has departed from the firing barrel
the rotor 20b is rotated for the purpose of closing the fuse or
firing chain 17a, 22a, 27a. The inertia body 61, upon impact of
he projectile at the target, is braked by the piezoelectric ,
crystal 59. The current which is gene~ated due to loading of the
?iezoelectric crystal 59 by means of the inertia body 61 is used
for controlling the ignition of the flame ignition means 17' in
the detonator cap 17a. By means of the detonator cap 17a there is
initiated through the agency of the detonator 22a and the reinforce
~ent charge 27a the detonation of the projèctil~ explo~ive charge ,
28a.
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By virtue of the fact that the support 56 is advantage-
ously employed as the armature core the length of the cage 55 can
0 be maintained relatively smal3.. Due to khis saving of space in the
axial direction the projectile can be provided with a greater
. quantity of explosive cha~ge 28a.
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While there is shown and described present preferred
embodiments of the invention, it is to be distinctly understood
that the invention is not limited thereto,but may be otherwise
. variously embodied and practiced within the scope of the following
claims. ACCORDINGLY,
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