PT781975E - MECANO-ELECTRONICA GARDEN FOR MAO GRENADE - Google Patents

Abstract

It consists of conventional mechanical carriage and handling safety-devices and safety-devices functioning mechanically and electronically. An original autonomous electric supply system. An electronic rather than a pyrotechnic delay. An explosive chain that changes from being misaligned to being in line, and able to trigger the detonation of the main charge in a hand-grenade. The energy required for it to function is stored in a spring (205) driving an electric generator (501), which improves storage, handling and use safeties, and the repeatability of the delay at any temperature, concurrently very substantially extending its useful life. <IMAGE>

Description

DESCRIPTION

MECHANICAL-ELECTRONIC GUN FOR HAND GRENADE

FIELD OF THE INVENTION The object of the present patent application is a Mechano-Electronic Fuze for Hand Grenade which, in addition to the function for which it was designed, provides a number of advantages described below, and others which are inherent in its organization and constitution.

BACKGROUND OF THE INVENTION

One of the most widespread types of ammunition in all armies in the world is, as it has been for a long time, the hand grenade. The usefulness of this ammunition is dependent on the strength of its explosive charge and the characteristics of its fuses. The fuse must be absolutely safe during storage, transport and launch. It must also ignite the explosive charge or after a delay once the grenade is dropped, or when the grenade hits a solid object.

Typical solutions to provide a delay have hitherto consisted in the use of pyrotechnic elements based on the use of mixtures of materials with which a particular combustion rate or mechanical or clock delays are achieved.

Elements of this type have the following drawbacks, among other things: - The delay achieved is irregular. - Its characteristics are degraded due to exposure to extreme environmental conditions. - The ability to withstand vibrations, shocks, etc. is small. 1 - The service life is limited. - Safety is not absolute under storage conditions.

The above mentioned resulted in multiple accidents due to either spontaneous explosions under non-operative conditions or unexpected shortening of the delay when in use.

From DE-A-2 147 172, which is the basis of the preamble of the main claim included, there is known a mechanical-electric fuze for hand grenade with a mechanical drive based on energy stored in a conventional spring. The electrical energy required to operate the detonator is obtained by generating electrical energy by means of a pendulum, moved by the spring and acting on one or two piezoelectric elements. This type of electric generator does not require external power sources. The familiar hand grenade fuze is convenient for delay and / or impact functions. FR-A-2483068 discloses an electronic fuze for a grenade, comprising a detonator, activated by a striker, an ignition means disposed between the detonator and the grenade loading, and a separating means between the detonator and the ignition means , and further comprising an electronic circuit for delayed activation of the detonator. The electronic circuit includes an electric power source, which may consist of a quartz generator or an accumulator.

SUMMARY OF THE INVENTION It is an object of the invention to provide a mechanical-electronic fuze for a hand grenade, which is absolutely safe in its functions over a long period of time and under all circumstances.

This object is achieved by a mechanical-electronic fuze according to the main appended claim.

Sub-claims appended thereto are directed to advantageous embodiments and features of the inventive mechanical-electronic fuze. The mechanical-electronic hand grenade wrench of the present patent application provides improvements and original elements with respect to fuses designed for similar use because: - It is absolutely safe under non-operative conditions during storage and handling. - It is absolutely safe for some time after launch, this time being pre-set and constant. - Neither its safety nor its operation is altered by electromagnetic fields. - It allows the explosive charge of the hand grenade to be released either after a delay or by impact, and also by a combination of delay and impact. - Delays are controlled electronically which, unlike the currently existing pyrotechnic delays, renders them entirely independent of external conditions such as atmospheric temperature, and furthermore ensures a high repeatability of the set values. - It can be attached to most hand grenades now in service without requiring any significant changes. - Its useful life is equivalent to that of the conventional explosives used in the main explosive charges of hand grenades. - She's completely maintenance free. The present patent provides the advantages described above as well as others which will easily result from the realization of a hand-held mechanical hand-held fuze, which is hereinafter described in detail for easy understanding of the features set forth above, while giving a number of details and annexing to the present specification for this purpose some drawings showing a practical example of the object of the present invention which is intended to illustrate and not limit its scope. 3

Brief description of the drawings.

In the drawings: Figure 1 is an external side view of an embodiment of a mechanical-electronic fuze adapted to the body of a hand grenade. Figure 2 is a 90 ° rotated view with respect to the preceding figure.

Figures 3, 4 and 5 show the same number of internal views of an embodiment of a mechanical-electronic fuze.

Figures 6 to 9 illustrate successive stages of operation of the mechanical-electronic fuze. Figure 10 is a diagram of an electronic module.

Description of an Embodiment of the Invention. The mechanical-electronic fuze proposed in the present patent application was designed for use in hand grenades, notwithstanding without limitation. Its outer shape is therefore adapted to be adjusted in widely used hand grenades today, although it may be adapted to any other shape with only slight changes.

A particular embodiment of the disclosed design among the many possible embodiments is described below. This will comprise: - A container (100) including all parts in view, except the parts of the Safety Lever Device (200). - A Safety Lever Device (200) which holds the fuse securely unmanaged and thrown. This Safety Device is completely conventional and should simply block the main spring which stores the required functional energy. 4 - A Propeller (300) providing the functional energy required by the Mecano-Electronic Fuze. - A Cursor (400) containing the Electronic Module (500) and incorporating part of the Explosive Chain (600). An Electronic Module (500) producing the electrical energy by means of a generator and using such energy for the purposes intended for a fuze. - An Explosive Chain (600) including the elements needed to detonate the explosive charge on the hand grenade under a suitable stimulus. The Container 100 in turn includes:

A Head (101) being the only part of the Mechano-Electronic Fuze protruding, though only partially, from the body of the hand grenade into which it is fitted. It has the elements necessary to register all the elements it contains, an outer thread to be attached to the body of the hand grenade, and an internal thread to be attached to the Bottom (103). It is provided externally with a protrusion 1011 in which the Ring 207 engages and is thereby secured. - A body (102). It is shaped like a vessel and made to protect the Electronic Module (500) from any external electromagnetic influences. The Cursor (400) can slide inside it. It has a thread to be connected to the Neck (103) and an inner protrusion (1021) preventing rotation of the Cursor (400) but allowing its sliding. A Bottleneck (103) serving to securely and sealingly connect the two main parts of the Container (100), the Head (101) and the Body (102). It houses and provides registration for the Propeller (300). The Safety Lever Device 200 may, as already said, have a conventional design. One possible embodiment thereof is described as an example, which may include: A cylindrical bolt (201) inserted in the head (101). Its central portion has a cavity (2011) which may or may not allow the Pinion (401) to pass through, depending on its position. It is provided with plans or a groove (2012) at each end in the area outside the Head (101) to allow its position to be secured. A flat contour (2013) limits its rotation by 90 ° from its non-operative position. - Two O-rings (202) sealing the cavity in the Head (1019) where the Bolt (201) is housed. A lever (203) whose shape fits the palm of the hand. Its end engages the planes or groove (2012) in the Bolt (201) so that the Lever (203) and the Bolt (201) rotate together. The shape of this Lever 203 and the ends of the Spring Axle 204 projecting from the Head 101 prevent the Lever 203 from prematurely releasing the Bolt 201 even though the hand grenade is gripped with little force . - A Spring Axle (204) fitted in the Head (101). - A Spiral Spring (205) with two arms, rotating about the Spring Axis (204) and serving to raise the Lever (203). A Pin 206 inserted into the Head 101 and preventing the Turning Lever 203 a Ring 207 designed for expeditious removal of the Bolt 206. In the described embodiment, however without limitation, this part is independent of the Bolt (206). Its shape and arrangement ensure that no involuntary removal of the Bolt (206) can occur. In order to prevent its displacement, it engages the protrusion (1011) of the Head (101) when it is not operative. The Propeller (300) includes: - A Helical Spring (301) providing the energy for the Mechano-Electronic Fuze to work. One of its ends is secured to the Vessel 302 and the other to the slot 3031 in the Crown 303. - A Vessel (302) containing and limiting the Helical Spring (301). Once assembled it is fixed to the Bottleneck (103). A drive transmission system capable of adapting the movement generated by the Helical Spring (301) to the input needs of the Generator (501), and comprising in the case being described, notwithstanding, without limitation, a gear train including: - A Crown (303) having an inner gear and an outer thread attaching it to the Bolt (402) of the Cursor (400). It is actuated directly by the Helical Spring (301) and is engaged in its grooves (3031). An intermediate pinion (304) including two sprockets (3041 and 3042) each having a different number of teeth. It transmits the rotation of the Crown (303) to the Pinion (401) by properly modifying the number of revolutions. The Cursor 400 includes: A Pinion 401 having a very long gear 4011 to allow the Cursor 400 to move. It is firmly connected to the Axis 5011 of the Generator 501 and meshes with the output gear 3042 of the Intermediate Pinion 304. - A Nut (402) which is screwed to the Crown (303). It allows the Pinion (401) to rotate inside it - A Casing (403) containing the Electronic Module (500) and securing it to the Nut (402). It is tubularly shaped 4031 at its lower end to serve as a position indicator for the Detonator 601 and as an obstruction to the Barrier 603. The Electronic Module 500 includes: A Generator 501 actuated through its Axis 5011 by the Pinion 401 to generate electrical power for the Electronic Module 500 to work. It is connected to the Frame (502) by means of conductors (5012). A printed circuit board 502 to which all electronic components, such as capacitors, diodes, resistors, transistors and analogue switches are soldered, as required to operate as described in the relevant section (numbered from 511 to 523) and lanes to connect such elements. - A Switch (503) keeping the Detonator (601) short-circuited when not in use.

There are alternatives to the embodiment described as the preferred embodiment which could be advantageous. Some are as follows:

Replacing the Switch (503) with its relay forming part of the Electronic Module (500) and keeping the Detonator (601) short-circuited when not in use. It will then be possible for the Detonator (601) to be short-circuited when not operative, since the release of such a short-circuit will not depend on a mechanical-type conductor.

Deleting the Switch (503). The Electronic Module 500 is therefore simplified, and the operation of the Detonator 601 is not dependent on mechanical motions. In addition, when not operative, the Detonator 601 is kept in a closed circuit which, despite a short circuit, is entirely safe.

Including an impact detector of any kind universally known and sufficiently tested (ball, floating striker, etc.) adds the possibility of its impact operation or a combination of impact and delay without substantially altering the concept description of this Mecano- Electronics. The Explosive Chain (600) includes: - An electrically stimulated Detonator (601). This connects to the Electronic Module via Conductors (601). It is inscribed in the tubular shape 4031 of the Casing 403 and is secured thereto. This element may be any of those available on the market. - A cylindrical hollow Multiplier 602 allowing passage of the tubular shape 4031 of the Casing 403 and the Detonator 601 therethrough. It is attached to the Body (102). A barrier 603 made of a form and a resistant material such as to be able to withstand the detonation of the Detonator 601 in its non-operative misaligned position without such detonation being transmitted to either the Multiplier 602 or to the explosive charge on the hand grenade.

Operation. a) During the storage and transport of a hand grenade equipped with the Mechanical-Electronic Fuze object of the present patent application, the Bolt 206 prevents the Lever 203 from moving, and the Bolt 201 is therefore maintained arranged against the forward movement of the Pinion 401 The Bolt 201 thereby prevents the forward movement of the Cursor 499 which is in turn screwed to the Crown 303 and therefore any movement of the mechanism is completely prevented , although the Helical Spring (301) tends to turn the Crown (303). Detonator 601 is short-circuited through Switch 503 and is further misaligned relative to Multiplier 602 and closed between Barrier 603 and tubular form 4031 of Housing 403.

In the highly improbable case of the Detonator 601 blowing in such a position, the Multiplier 602 is protected by the Bar 603 and the shock wave generated by the Detonator 601 scrapes the bottom 1022 of the Body 102 and bottom of the body of the hand grenade, sedo lost to the open air without causing further damage. This is why the detonation of the explosive charge on the grenade will never be induced, that is, the negative operation is prevented.

Given the overlap of the securities described above, the Mechano-Electronic Fuze for hand grenade object of the present patent application is completely safe. Since the chance of the hand grenade exploding by chance becomes dependent only on the main charge, this possibility is greatly minimized. (b) In view of the use of the hand grenade, the latter is gripped ensuring that it is firmly grasped and with the lever (203) directed towards the palm of the hand. The Ring 207 is removed from the housing 1011 and is used to remove the Pin 206. After that, anything that prevents Spring (205) from turning the Lever (203) is the palm of the launcher's hand. The process is absolutely conventional up to this point. When the launch takes place and the hand grenade leaves the hand of the launcher, the Spring 205 pushes the Lever 207, causing it to rotate, and because of its fit into the flats or groove 2012, the Ferrolho (201) also rotates.

When the Bolt 201 reaches the limit imposed by the plane (2013), the cavity (2011) is directed so as to allow the Pinion (401) to pass therethrough.

When the Pinion (401) is released, the complete Cursor (400) can move forward and this allows the Crown (303) to rotate.

As the Helical Spring (301) causes the Crown (303) to rotate permanently, the latter begins to rotate. The rotation of the Crown (303) has two simultaneous and independent effects. On the one hand, and through the thread connecting it to the Bolt (402) it pulls from the latter until both parts abut. As the Thread is firmly attached to the Cursor (400) they move together. Since the Detonator 601 is connected to the Envelope 403, it moves along with the complete Cursor 400 and upon reaching the end of its displacement is aligned with the Multiplier 602 - inserted therein. d) At the same time, when the Cursor 400 reaches the end of its displacement, the Inner Boss 1201 actuates the Switch 503 that opens the Short Circuit of the Detonator 601. e) In addition, and by means of the Intermediate Pinion 304, rotation of the Crown 303 causes rotation of the Pinion 401. This rotation is independent of the forward movement of the Cursor 400 due to the length of the gear 4011 of the Pinion 401. 10

Since the pinion is firmly connected to the axis 5011 of the Generator 501, it forces it to rotate and the generator 501 generates electrical energy. Energy reaches the Frame (502) through the Conductors (5012). f) Diode 511 prevents the electronic circuit from being discharged if there is a short-circuit outside the Frame 502. The Condenser 512 stores the energy generated by the Generator 501. The Resistance 513 works as a drain for the Condenser 512. The Resistance 514 and the Condenser 515 form a first order analog delay which regulates a post-launch time in which no energy is available to the Detonator 601. g) After the preset time in the analog delay 514-515 is elapsed, the latter actuates the Analog Switch 516 which allows the power to flow to the Capacitor 521. The Resistance 518 and the Condenser 519 form another first-order analog delay which controls the time at which the Mechanical-Electronic Spike will put the Detonator 601 in activity.

This delay (518-519) is now mentioned to improve understanding of the circuit, but actually begins counting at the same time as (514-515) described above. h) When the time pre-set by the analog delay (518-519) elapses, the latter actuates the Analog Switch (520). The Analog Switch (520) causes the Transistor (522) to be switched. I) When the Transistor (522) is switched, it has all the energy stored in the Condenser (521) discharged to the Detonator (601). As already described above, the Switch 503 which must keep the Detonator 601 short to the ground for the entire time of storage, transport and handling should have changed its state when the Cursor 400, completes its forward movement, interrupting the short circuit and connecting the Detonator (601) to the Transistor (522).

If the Switch 503 actually changed its state, when the Capacitor 521 discharges through the Transistor 523, this discharge will parallel the Resistor 523 and the Detonator 601, which is acted on.

If, however, the Cursor 400 does not complete its movement, the Switch 503 will continue to keep the Detonator 601 short-circuited and separate from the Condenser 521 and the energy will thereby be lost through the Resistance 523 ), which acts as a drain.

Now, therefore, the mechanical-electronic fuze object of the present patent application guarantees a post-launch safety time during which no energy is available to cause detonation, and very reliable operation after a delay, adjustable by design, and controlled.

In addition, the mechanical-electronic fuze object of the present patent application ensures that, if the detonator 601 is detonated and since the latter has to be brought in line with the Multiplier 602, the detonation should pass to the Multiplier (602) and for that reason for the explosive charge of the hand grenade. The operation of the alternative solutions mentioned in the System Description will be as follows:

Replacement of the Switch 503 by an electrical relay: this coincides with that of the preferred solution up to g), where, in addition to allowing the passage of energy through the Capacitor 521, the relay is also actuated, changing its and by stopping the shorting of the detonator (601), by connecting it to the transistor (523). Points d) and j) are eliminated. 12%

Eliminating Switch (503): When not operational, Detonator (601) is in closed loop through Resistance (523). In operation, points d) and j) are eliminated.

Inclusion of an impact detector: this switch may be arranged instead of the analog delay (518-519). Thus, after the safety devices have been released, the fuse will be ready to operate by impact against the ground or against any obstacle.

It can also be arranged in parallel with the analog delay (518-519). Thus, after release of the safety devices, the fuse will be ready to operate by impact against the ground or against any obstacle, and if the impact does not occur or is not sufficient to trigger the impact detector, the explosion will take place after a delay.

Since the concept of an impact detector is widely disseminated, that multiple specific embodiments of such a device are known, and that the inclusion of such an element acting as a switch does not alter the essence of the object of the present patent application, it is not described after all.

Lisbon, .Π 2 Kõ ¥. 2úú'i By INSTALAZA S.A.

13

Claims (13)

A mechanical-electronic hand grenade fuze, including a spring (301) for storing mechanical energy, a mechanical impeller (300) coupled with said spring for imparting a means for generating electric energy required to act a detonator (601) , characterized in that said means for generating electrical energy is constituted by an electric generator (501) comprising a rotational axis (5011) for its actuation, which is driven by said mechanical propeller (300) A mechanical-electronic fuse according to claim 1, characterized in that a slider (400) is provided, which is driven by said mechanical impeller. A mechanical-electronic fuze according to claim 2, characterized in that said detonator (601) moves together with said slider (400), and reaches at one end of the slider displacement a position such that it is aligned with a multiplier ( 602). A mechanical-electronic fuse according to claim 3, characterized in that a barrier (603) is provided, which protects the multiplier (602) of the detonator (601) in its misaligned positions. A mechanical-electronic fuse according to any one of claims 2 to 4, characterized in that said slider (400) activates at the end of its displacement a switch (503), which opens a short circuit of said detonator (601) . A mechanical-electronic fuse according to any one of claims 1 to 5, characterized in that said mechanical impeller comprises a rotatable crown (303) driven to rotate by said spring (301) and rotatably connected with said axis (5011). 1 A mechanical-electronic fuse according to any one of claims 2 to 6, characterized in that said rotary crown is threadably connected with a screw (402) firmly connected to said slider (400) so as to linearly move said slider rotation of said crown. A mechanical-electronic fuze according to claim 7, characterized in that said crown (303) is rotatably connected to said generator shaft (501) by an intermediate pinion (304) including two toothed wheels (3041, 3042) for transmitting the rotation of the crown to a pinion (401) firmly connected to said axis, wherein said pinion has a long gear so as to allow the slider (400) to move. A mechanical-electronic fuse according to any one of claims 1 to 5, characterized in that said detonator (601) is connected to said generator (501) via an electronic circuit. A mechanical-electronic fuze according to claim 9, characterized in that said electronic circuit provides double adjustment in order to avoid activation of the detonator during the first instants of flight of the hand grenade and then to ensure the activation after a pre- adjusted. A mechanical-electronic fuse according to claim 1, 5, 9 or 10 characterized in that said detonator (601) is connected to said generator (501) via an electronic circuit which includes an impact detector either for activating said detonator after the release of the mechanical drive means, or to drive said impact generator. A mechanical-electronic fuse according to any one of claims 9 to 11, characterized in that the electronic circuit comprises means (523) ensuring a self-discharge of the electric energy in the case in which after generation of the electric energy required to activate the detonator ( 601) the latter is not detonated. A mechanical-electronic fuse according to any one of claims 1 to 12, characterized in that a means (201, 203, 205) is provided enabling the mechanical propeller (300) to drive the electric generator (501) only after the hand grenade in which the mechanical-electronic fuze was set. 2 Lisboa, * í í 1 ^ · 2001 By INSTALAZA S.A. 3