FR2559895A1 - Hand grenade - Google Patents

Abstract

Hand grenade operating either by the shock of impact, occurring after a predetermined time, or by a delay whose duration is also predetermined, whose functioning is initiated by an igniter plug with an electronic processing circuit actuated when throwing the grenade by the ejection of a safety pin, characterised in that the said processing circuit 17 is preferably based on hybrid components using integrated circuits in the form of "chips" and capacitors in the form of "chips", and in that it comprises digital timers 30, 31 allowing relatively long and precise delay times to be obtained using capacitors of low value, and in that means 4 are provided allowing the choice of functioning on the shock of impact and/or with a pre-established delay.

Description

Hand grenades have been used for many years,
especially as anti-personnel weapons. They are fitted with an igniter plug to make them explode, either on impact or with a specific delay, lasting up to a few seconds.

 Most of the systems used today are based on mechanical, clockwork, pyrotechnic operating principles, with or without delay. These various known systems are complicated and unreliable, or else they give rise to random delay time values, sensitive to aging during their passive life.

 They also have a high sensitivity to falling. This drawback is detrimental to safety, and can even lead to fatal accidents, for example if the combatant unexpectedly drops the pinned grenade before throwing it.

 The present invention proposes to provide a hand grenade which does not have the drawbacks of known hand grenades.

To this end, the invention relates to a hand grenade ensuring the neutralizing, annoying and fusing, or percussive-fusing functions, which comprises an igniter plug with electronic processing circuit actuated, at the time of launching, by the ejection of a safety spoon, and powered by a bootable battery. According to the invention, the processing circuit is based on hybrid components, preferably using integrated circuits in the form of "chips" and capacities in the form of "ultra-thin capacities", and means are provided allowing the choice of operation. : on impact shock and / or
with a pre-established delay,
The igniter plug also ensures the safety of the pyrotechnic chain interruption. It is placed, according to the invention, in the "middle" of the grenade, between two half-bodies in explosive mounted on either side, and it is organized so as to produce little or no chips.

 Furthermore, the hand grenade according to the invention comprises an impact shock detector produced by a multidirectional network of piezoelectric films, preferably placed inside the two explosive half-bodies.

In addition, the hand grenade according to the invention makes the widest use of molded plastics of low density, in order to transfer as much as possible the mass gained on the useful products.
- either, for the grenade in neutralizing version, on the explosive while reducing the production of fragments,
- or, for the grenade in vulnérante version, on the vulnantes fragments.

 The hand grenade, according to the invention, in its offensive version, comprises a removable outer sleeve, acting as a splinter intensifier, this sleeve being preferably made of heavy, prefragmented materials.

 This sleeve, according to the invention, is immobilized in place, by means of a simple threaded ring. At the lower end of the grenade body equipped or not with the splinter-reinforcing sleeve, it is possible, optionally, to fix a handle or a handle helping to launch.

The various characteristics and advantages of the invention will emerge from the description below. It is clearly specified, however, that these are only examples and that all the other modes of construction, shapes, proportions, arrangements, etc. can also be used without departing from the scope of the invention.
- Figure 1 shows an "exploded" view of the hand grenade in all of its versions, according to the invention;
- Figures 2, 3 and 4 are respectively views in longitudinal section, in cross section along 3-3 of Figure 2 and from above, of the hand grenade neutralizing version, according to the invention, in safety position
- Figures 5, 6 and 7 are respectively views in longitudinal section, in cross section along 6-6 and in top view of the same version of neutralizing grenade, according to the invention, but in the launch position;
- Figures 8 and 9 show an external longitudinal view and an external end view of the hand grenade, in a pungent version, according to the invention
- Figure 10 illustrates an exemplary embodiment, in the form of a block diagram, of the electronic processing circuit;
- Figures 11 to 16 show the shape of the signals and response of the circuits in all cases of configuration of possible operations, depending on the position of the selector
- Fig. 1 1 - percussive-fusing position - impact shock detected before chosen time (less than a second, for example) - circuit inhibition: close impact safety or fall
- Fig. 12 - percussive-fusing position - impact shock detected between two selected time limits - percussive operation at impact (for example, less than a second on the one hand and a few seconds on the other)
- Fig. 13 - percussive-fusing position - impact shock not detected operation by fusing beyond a predetermined time, for example more than a few seconds
- Fig. 14 - fusing position - impact shock detected before urX chosen time (less than a second, for example) - circuit inhibition: close impact safety or fall
- Fig. 15 - fusing position - impact shock detected between the two time limits above - fusing operation beyond a few seconds
- Fig. 16 - fusing position - impact shock not detected - working
while fusing beyond a few seconds.

Referring first to Figure 1, it can be seen that b hand grenade, according to the invention, comprises the following main constituent sub-assemblies
a) An igniter plug assembly 1 placed in the "middle" of the grenade, ensuring all the operating and safety configurations of the grenade, the choice of the fusing or percussive-fusing version being carried out by means of a lever external control 4, mounted at the end of the axis 4 ';
b) an explosive assembly divided into two half-bodies 2 and 3 mounted on either side of the igniter plug 1;
c) a safety and handling kit consisting of a spoon
releasable 5 and a safety pin 6
d) a vulnering assembly 7 constituted by a splinter reinforcing sleeve
e) optionally, a grip or handle for launching 8
The whole of the igniter plug 1 which is in the form
a disc placed in the "middle" of the grenade, is made, according to the invention
a cylindrical body 9 made of molded plastic and a plug
shutter 10, also in molded plastic.

In this body 9, are placed all of the following components of the bou
dear lighter
First of all3 an electronic power supply which may be preferred
rence and according to the invention, a thermo-amorsEable 14 battery comprising a calcium-based electrolyte. Before initiation, that is to say storage and before launch, the electrolyte is solid, therefore the battery is inert, this which represents absolute safety in handling, according to the invention At the time of launch, the battery is initiated, according to the invention, by a percussive primer 14 ', thanks to the action of a striker 15 and of its spring 16. I1 follows an exothermic reaction of the pyrotechnic composition contained in the battery 14 which brings the electrolyte to the liquid state. The battery is then "activated".

 After several seconds (10 seconds for example), and if the grenade does not work, the electrolyte becomes solid again by cooling and, according to the invention, the battery is made inert again, whence a grenade rendered inert , which guarantees range safety.

 The very short active life of the battery, of the order of a few seconds, corresponds to the liquid phase of the electrolyte.

 This type of battery has a very short response time, on the order of a small one. Fraction of a second. It is capable of delivering a current of a few tens of m.A in continuous mode, as well as a peak current of a few amps.

 It is understood that any other kind of electrical energy source can be used and falls within the scope of the present invention.

 The percussion and arming mechanism comprises a plug 11, located in a diametrical plane of the igniter plug 1, an arming spring 12, mounted on the rear part of the plug 11, a priming relay 13, mounted in the middle of the bushel 11, the rotary striker 15, with its spring 16, controlled by the bushel II, and located laterally thereto, in front of the heat-initiating stack 14.

 According to the invention, the electronic processing circuit 17 is in hybrid form, using integrated circuits in the form of "chips" and dercapacities in ultra-thin form, ensuring all the functions of the grenade and the details of operation of which are described below. This modern embodiment is particularly suitable, by its volume and reduced cost, for the dimensions of the grenade and its wide distribution.

 An electrical detonator primer 18 constitutes the source of initiation of the igniter.

The explosive assembly, formed by two half-bodies 2 and 3, located on either side of the igniter plug 1, according to the invention, consists
- an upper half-body 1 9 of molded plastic, comprising a block of compressed explosive 20, provided axially with a priming column 21, according to the invention,
- A lower half-body 22, also molded plastic and comprising a compressed explosive block 23 and an axial priming column 24, according to the invention.

 The compressed explosives and the priming axial columns can be, for example, in hexogen-wax 9515 or 98/2. Of course, these examples are not limiting.

 The two half-bodies 19 and 22 are fixed on either side of the igniter plug assembly 1, by gluing for example, on the sockets 19 'and 22'.

 The assembly thus produced constitutes, according to the invention, an axial continuous ignition column with the relay 13 of the plug, once the arming of the grenade carried out (interruption of the pyrotechnic chain lifted).

 The upper body 19 comprises a boss 50, coming from molding and an axis 51 serving to hold the spoon 5 and to articulate during its ejection.

 The lower body 22 comprises a boss 52, coming from molding and comprises a hole 53 for the passage of the safety pin 6 and another boss 25, provided with a threaded bore, intended to receive, according to the invention, a threaded ring 26, for quick attachment of the assembly below.

 Between the walls of each half-body, 19 and 22, and the explosive blocks 20 and 23, there are, according to the invention, the piezoelectric films 29 of the impact detector, producing a multidirectional network, connected to the electronic circuit. 17, triggering the impactful operation.

The safety assembly is made up, according to the invention, of the ejecting spoon 5 and the safety pin 6
The spoon assembly 5 according to the invention comprises a shaped part, metallic or plastic for example, bearing, on the one hand, on the axis 51 and the pin 6 at 53 and, on the other hand, on the rod 54, forming the end of the plug 11, by means of the central part 5 ′, and orienting it, according to the invention, thanks to the slot 54 ′, provided at the end of the rod 54, a seal 5 "ensuring the tightness of the assembly.

 The vulnering assembly 7 consists, according to the invention, of a reinforcing sleeve, enveloping the body of the grenade. It has, on a generator, an opening 7 'corresponding to the width of the spoon 5, to allow the free passage of the latter at the time of its ejection. This sleeve is formed of a metallic casing 27 with prepared pre-fragmentation, of selected thickness, depending on the desired efficiency and the mass requirements (preferably, pseudo-cubes or balls; non-limiting examples).

 The envelope can also be made up (also nonlimiting examples) of stacked open rings 27 ′, the pre-fragmentation of which is obtained by broaching, or of a grooved plate and shaped after machining. The whole is overmolded in a plastic envelope 28.

 The annealing assembly 7 is fixed to the lower half-body 9, using the threaded ring 26, with rapid pitch, which is screwed into the bore of the boss 25.

 One can, of course, without departing from the scope of the invention, consider any other method of producing the splinter-reinforcing sleeve.

 The launching handle or handle 8 can optionally be fixed by its thread 8 ′, screwing onto a threaded bore of the ring 26 or onto the threaded bore of the boss 25 of the half body 3 of the grenade, in the case where this it is not provided with the reinforcing sleeve 7 and its fixing ring 26.

The operation of the grenade is as follows:
According to the invention, after having fitted or not the grenade with the reinforcing sleeve 7 and the launching handle or handle 8, the user chooses the operating mode: percussive, percussive-fusant, or fusant, by acting on the lever. control 4. Figures 7 and 9 show two positions of the lever 4, which correspond to two different operating modes.

 These maneuvers are completely reversible.

 To launch his grenade, the servant, withdraws the safety pin 6; from the release of the grenade, the spoon 5 rotates around its axis of articulation 51 thanks to the presence of the spring 12. This spring 12 presses on the plug 11, that by its rod 54, pushes back the central part 5 'and causes the ejection of the spoon 5, after a rotation of at least 90.

The advancement of the plug 11 causes, according to this invention, the alignment of the pyrotechnic channel (priming relay 1 3, with the primer - detonator 18 and the priming columns 21 and 24 of the two half body 2 and 3),
In the same movement and, according to the invention, the spring 16 of the striker 15 of the bootable stack 4, is energetically bandaged; at the end of stroke of the plug 11, the striker 15 escapes (Fig. 6), the spring 16 relaxes and the striker 15 strikes the primer 14 'of the primable stack 14, parsed at its tip 15'.

 The processing circuit 17 is, according to the invention, initiated by the battery 14. An embodiment of the processing circuit, according to the invention, is shown in Figure 10, in the form of block diagram.

 The operation of this circuit is explained by the patterns of the signals at different points of the electronic circuit, according to Figures 11 to 16 inclusive.

 This circuit is characterized, according to the invention, by the use of digital timers 30 and 31, making it possible to have very long and precise delay times, with capacities of low values.

 The logic circuits are, for example, CMOS (32 to 37 inclusive) whose noise immunity is known.

 The initiation firing control circuit is, for example, constituted by a VMOS 38 technology transistor, suitable for this type of application.

 The pulse shaping circuit 39, supplied by the piezoelectric shock sensor 29, as well as its memory 40, are produced using a CMOS device of the threshold comparator type for example.

 External switching (control lever 4) allows switching from the percussive-fusing operating mode to the fusing or percussive operating mode alone, as indicated above.

 Of course, all the examples above are indicative. All other circuit modes fall within the scope of the present invention.

The chronology of operation is as follows:
- when the spoon 5 is ejected, the striker 15 initiates the heat-initiating battery 14 which activates the ignition circuit
-the timer 31 (0.6 s for example) condemns the logic outputs 32 to 35, for the duration of its operation
- any signal from the piezoelectric contact 29 makes the system inert by inhibiting the logic circuit
- if no signal has intervened during this delay, depending on the operating mode chosen3 one obtains
- or a fused operation at the end of the delay 30 of a few seconds (5 s for example), which controls the logic outputs (32 to 36), the signal of the piezoelectric contact 29 being eliminated by manual control 4
- either a fusing or percussive operation if the piezoelectric sensor 29 is connected by manual control 4.

Claims (19)

 1 - Hand grenade operating either by impact shock, intervening at  beyond a predetermined time, either by delay of a duration also predetermined threaded, the operation of which is initiated by an igniter plug with electronic processing circuit, actuated, when the grenade is launched, by the ejection of a spoon security, characterized in that said processing circuit (17) is based on hybrid components, preferably using integrated circuits in the form of "chips" and capacitors in ultra-thin form, in that it includes timers digital (30, 31) making it possible to obtain relatively long and precise delay times, using capacitors of low values, and in that means (4) are provided allowing the choice of operation, at shock to impact, and / or with a pre-established delay.  2 - Hand grenade according to claim 1, characterized in that the logic circuits (32 to 37) of the processing unit (17) are C MOS circuits.  3 - Hand grenade according to one of the preceding claims, characterized in that the ignition control circuit of the primer consists of a transistor (38) of V MOS technology.  4 - Hand grenade according to any one of the preceding claims, characterized in that the shaping circuit (39) of the pulse supplied by the impact shock detection means (29), provided in the grenade, is produced by a C MOS threshold device, of the threshold comparator type.  5 - Hand grenade according to any one of the preceding claims, characterized in that the igniter plug (1) forms a disc and is located in the "middle" of the grenade, between two explosive half-bodies (2, 3) mounted on either side of said igniter plug.  6 - Hand grenade according to claim 5, characterized in that each explosive half-body (2, 3) is provided axially with an axial priming column (21, 24), so as to constitute an axial column of continuous ignition with the ignition relay (13), when the arming of the grenade is carried out.  7 - Hand grenade according to any one of the preceding claims, characterized in that the igniter plug (1) comprises, in addition to the electronic treatment circuit (17), all the other active constituents in the operation of the grenade: power supply (14 ) pyrotechnic chain interruption and safety control devices, initiator-detonator (18), ignition relay (13).  8 - Hand grenade according to any one of the preceding claims, characterized in that the supply is carried out by a thermo-primable battery (14) with calcium-based electrolyte, solid in storage, which is initiated at the time of launch by the action of a striker (i (15), triggered by a spring (16) on a primer (14 ') of said cell, which causes an exothermic reaction of a pyrotechnic composition contained in the cell itself, and which carries the electrolyte in the liquid state.  9 - Hand grenade according to claim 8, characterized in that, after launch and impact on the ground without functioning, the electrolyte of the battery (14) becomes solid again by cooling effect, thus rendering the grenade inert.  10 - Hand grenade according to one of claims 8 or 9, characterized in that the thermo-bootable battery (14) has a very short response time and a very short life time, consistent with the military requirements demanded of it. type of pomegranate.  11 - Hand grenade according to any one of the preceding claims, characterized in that, at the time of launching, after having removed the safety pin (6), the expensive of the safety spoon (5) authorizes the advancement a relay plug (11), the alignment of the technical pyron chair, the percussion of the primer (14 ') of the heat-removable battery (14), hence the initiation of the electronic circuit of treatment (17) and the ability of the grenade to operate on impact or in a delayed position.  12 - Hand grenade according to any one of the preceding claims, characterized in that the means ensuring the detection of the impact shock is produced in the form of a multidirectional network of piezoelectric films (29), placed inside the two explosive half-bodies (2, 3), between the wall and the explosive.  13 - Hand grenade according to claim 12, characterized in that the impact shock detection network (29) is designed so as to render the system inert, by inhibiting the logic circuit of the processing unit (l7 ), in the event of an unexpected fall of the stripped grenade before launch.  14 - Hand grenade according to any one of the preceding claims, characterized in that the selection of the operating mode is carried out by a lever (4), preferably with reversible selection maneuver, located outside the grenade , acting on the electronic processing circuit (17).  15 - Hand grenade according to any one of the preceding claims, characterized in that it comprises a reinforcing sleeve of prepared metal shards (7), enveloping the body of the grenade, which is removable and rigidly linked to the part pomegranate lower by a rapid system.  16 - Hand grenade according to claim 15, characterized in that the splinter reinforcing sleeve (7) has a longitudinal opening (7 ') to allow the free passage of the safety spoon (5).  17 - Hand grenade according to one of claims 15 or 16, characterized in that the prepared flake intensifier sleeve (7) consists of a set of pseudo-cubes or balls, or stacked open rings, or a grooved plate shaped after machining.  18 - Hand grenade according to any one of the preceding claims, characterized in that it comprises a throwing handle or handle (8) mounted on the lower part of the grenade by means of a quick fixing system .  19 - Hand grenade according to any one of the preceding claims, characterized in that the structure of the two half-bodies of the grenade (2, 3) and of the igniter plug (1) is made of plastic.