WO2009106694A1

WO2009106694A1 - Support member and method for launching ammunition

Info

Publication number: WO2009106694A1
Application number: PCT/FI2009/050168
Authority: WO
Inventors: Lauri Pauniaho; Janne Tervokoski; Tomi Koho
Original assignee: Patria Land & Armament Oy
Priority date: 2008-02-28
Filing date: 2009-02-27
Publication date: 2009-09-03
Also published as: FI20085179A0; FI20085179L

Abstract

The present invention relates to a support member for launching ammunition from a barrel of a breech-loading weapon. The support member (8) comprises launching means (9) for launching an electric detonator (5) of a charge of the ammunition.The support member is characterized in that the launching means (9) comprise a capacitor (40), a control unit (90) provided with comparison means (94, 95) for monitoring a state/charge level of the capacitor, and switch means for conveying charge charged in the capacitor (40) to the electric detonator (5) of the charge of the ammunition. The invention further relates to a method of launching ammunition a barrel of a breech-loading weapon.

Description

SUPPORT MEMBER AND METHOD FOR LAUNCHING AMMUNITION

FIELD OF THE INVENTION

[0001] The invention relates to a support member for launching ammunition from a barrel of a breech-loading weapon, which support member keeps the ammunition in place in the barrel prior to its launching and comprises means for attaching the support member to a rear end of the ammunition such that the means become detached from the ammunition or break down upon launching, the support member comprising launching means for launching a charge of the ammunition.

[0002] The invention further relates to a method of launching ammunition from a barrel of a breech-loading weapon, the method comprising launching the ammunition by means of a support member which is to be attached to a rear end of the ammunition and which keeps the ammunition in place in the barrel prior to its launching, the support member comprising means for attaching the support member to the rear end of the ammunition such that the means become detached from the ammunition or break down upon launching, as well as launching means for launching an electric detonator of a charge of the ammunition.

BACKGROUND OF THE INVENTION

[0003] Today, mortars are installed on movable carriers so as to enable them to be moved from one place to another and, respectively, to exit a firing station speedily. A problem with such solutions is the ability of the carrier, i.e. vehicle, to defend itself against potential attacks, as well as its use for destroying targets on the ground in the immediate vicinity thereof. A moving carrier equipped with a heavy mortar is not normally capable of carrying heavy- duty defensing facilities as well, but it is at most provided with a heavy machine gun or corresponding lighter armaments. In such a situation, it is necessary for the vehicle to be capable of using also the mortar for horizontal fire or below; normal grenades and mortars are not suited for this. A grenade positioned inside a normal mortar with a smooth barrel is capable of moving when the mortar is horizontally placed or aligned below that in the barrel such that it either falls out of the barrel or moves a distance enough for the grenade not to be launched.

[0004] A problem with such weapons lies in that they may only be used for launching ammunition of a certain type since their launching system is not suited for launching ammunition of another type. For instance, a firing pin operated weapon cannot be used for firing ammunition equipped with an electric detonator.

BRIEF DESCRIPTION OF THE INVENTION

[0005] An object of the present invention is to provide a novel and improved support member and method enabling ammunition of a mortar, such as a grenade, to be kept with sufficient reliability in a correct position in a barrel of a breech-loading mortar as well as to operate reliably also when firing ammunition whose charge is equipped with an electric detonator.

[0006] A support member according to the invention is characterized in that the launching means comprise for launching an electric detonator, a capacitor, a control unit provided with comparison means for monitoring a state/charge level of the capacitor, and switch means for conveying the charge charged in the capacitor to the electric detonator of the charge of the ammunition.

[0007] A method of the invention is characterized by the method comprising: performing, due to the influence of the stroke of the firing pin of a weapon, a switching procedure in a current circuit, feeding current to a capacitor of the launching means, receiving information on a charge level of the capacitor by a control unit, comparing, at the control unit, the information on the state/charge level of the capacitor with a predetermined level, and upon the charge level of the capacitor reaching the predetermined charge level, performing by the control unit a switching procedure activating at least one switch in order to convey the charge charged in the capacitor to the electric detonator of the charge of the ammunition.

[0008] The invention is based on a circuit provided with a current source, wherein capacitors are charged and their charge is discharged upon launching to an electric detonator of the charge of the ammunition. An advantage is that a launching delay is considerably shorter than that in connection with an implementation merely based on a chemical solution of a battery. Further, a circuit according to the invention may be provided with sophisticated safety functions.

[0009] An idea of an embodiment of the invention is that the launching means of the support member further comprise a current source for feeding current to the capacitor. The current source may be formed from one or more batteries placed in the support member.

[0010] An idea of a second embodiment of the invention is that the support member is provided with reception means for connecting to a device positioned outside the support member. The reception means enable current feed to the capacitor to be implemented, or they may be utilized as one safety function. The reception means may be placed e.g. on an outer surface of the support member. The reception means enable information on the positioning of the support member in the barrel of the weapon to be conveyed to the control unit. An advantage is that the control unit does not allow the capacitors to be discharged to the electric detonator of the charge of the ammunition should the support member receive a launch-activating stroke in a situation wherein the support member is not positioned in the barrel of the weapon. Further, this may be utilized as a safety function in solutions where the capacitor is charged prior to the stroke of the firing pin of the weapon. An advantage is that the launching delay becomes even shorter since the delay in the charging time of the capacitor is omitted.

[0011] An idea of a third embodiment of the invention is that the reception means is an induction ring arranged to receive current from a current source which is located outside the support member and which conveys current according to an electromagnetic induction principle, and to convey this current in order to charge the capacitor.

[0012] An idea of an embodiment of the invention is that the method further comprises a step implementing regharging of the capacitor and conveying the charge again to the electric detonator if the launching of the ammunition is not successful the first time. An advantage is that when using a single- operated firing pin switch, it is possible to retry with no need to replace the support member.

[0013] An idea of another embodiment of the invention is that the method further comprises performing by the control unit a switching procedure activating at least one switch, such as a semiconductor switch, in order to short-circuit the capacitor via a current limiting resistor if the launch of the ammunition is not successful. An advantage is that the ammunition may be safely removed from the barrel of the weapon after a predetermined period of time.

[0014] An idea of a third embodiment of the invention is that the method further comprises transferring the control unit to a state which prevents launching. In such a case, a microcontroller of the control unit may inactivate itself by writing in the program memory information about the launching being unsuccessful, and new control voltage is no longer provided to the switches.

BRIEF DESCRIPTION OF THE FIGURES

[0015] The invention is now described in connection with preferred embodiments and with reference to the accompanying drawings, in which:

Figure 1A schematically shows a grenade supported by a support member according to the invention against a barrel of a weapon,

Figure 1 B is a rear view showing the arrangement according to Figure 1A,

Figure 2A is a partially sectioned schematic side view showing attachment of ammunition to the support member according to the invention,

Figure 2B is a schematic direct top view showing the support member of Figure 2A;

Figure 2C is a schematic direct rear view showing the ammunition of Figure 2A;

Figure 3A is a partially sectioned side view showing a launching situation of a grenade attached to the support member according to Figure 2A;

Figure 3B is a schematic direct top view showing an embodiment of the support member;

Figure 4 shows a schematic circuit diagram of a control unit of a support member according to the invention;

Figure 5A is a schematic partially sectioned side view showing attachment of ammunition to a support member according to a second embodiment of the invention,

Figure 5B is a side view showing the support member of Figure 5A; and

Figure 6 is a schematic partially sectioned side view showing a third embodiment of a support member according to the invention.

[0016] For the sake of clarity, the figures show some embodiments of the invention in a simplified manner. In the figures, like reference numerals identify like elements.

DETAILED DESCRIPTION OF THE INVENTION

[0017] In Figure 1A, ammunition, such as a grenade 1 , is arranged in a barrel 2 of a breech-loading weapon. The weapon may be a mortar wherein an inner surface of the barrel 2 is substantially smooth. A rear part of the grenade 1 is provided with a tail barrel 3, and a tail. The tail comprises one, or typically several, guide wing(s) 4 which may be used for influencing the trajectory of the grenade 1. The details of the construction of the grenade 1 may differ from the structure shown in the figure. For the sake of clarity, no breech or other details of the weapon are shown. To the rear part of the ammunition, i.e. in this case the tail of the grenade, a support member 8 according to the invention is attached, which enables the grenade 1 to be kept in place in the barrel 2 until being launched. An edge collar 87 provided in the support member 8 prevents the grenade 1 from moving forward in the barrel 2 when the barrel 2 is directed horizontally or even when the barrel 2 points downward, i.e. keeps the grenade 1 in place in the barrel prior to launching. Further, a back surface of the barrel of the weapon may be provided with a groove or a recession to receive the edge collar 87 included in the support member 8 when the grenade 1 equipped with the support member 8 has been charged into the barrel. The support member 8 is dimensioned such that in addition to loads due to the mass of the grenade 1 , it withstands potential forces due to vibration and accelerations.

[0018] Figure 1 B is a rear view showing the support member 8 arranged in the barrel of the weapon according to Figure 1A. The centre of the support member 8 is provided with a launch member 9 for launching the actual detonator of a charge of the grenade.

[0019] Figure 2A shows one support member 8 to be attached to the grenade 1. The centre of the support member is provided with attachment members 80 which extend from an upper surface of the launching means 9 in the direction of the grenade 1 such that they settle between guide wings 4 of the grenade 1 on top of the tail barrel 3. It is apparent that the attachment of the ammunition may be implemented in the invention in different ways. It is possible to implement the attachment also e.g. such that instead of the tail barrel 3, the attachment members 80 attach to the guide wings 4 of the grenade 1. The meaning of the attachement to the present invention is to keep the grenade 1 and the support member 8 attached to one another such that the launching means 9 of the support member 8 stay in contact with the electric detonator 5 of the charge of the ammunition.

[0020] The support member 8 further comprises an end 86, an edge shell 88, and an edge collar 87. The edge shell 88 in the support member 8 is dimensioned such that at least part of the tail of the grenade 1 may be received therein.

[0021] The centre of the support member 8 is provided with launching means 9 for launching the electric detonator 5 of the charge of the grenade 1. In this embodiment, the launching means 9 in the support member 8 comprise an intermediate firing pin 96, a firing pin switch 30, a current source 20, a capacitor 40, and a control unit 90. In connection with the intermediate firing pin 96 there is provided a locking member 97 which prevents the intermediate firing pin 96 from moving, but after the firing pin has struck on the support member, it yields such that the intermediate firing pin 96 is allowed to move, whereby a stroke of the firing pin of the weapon makes the intermediate firing pin 96 to perform a striking movement and activate the operation of the control unit 90. Via connectors 94, 95, the control unit 90 conveys the charge charged in the capacitor 40 to the electric detonator 5 of the charge of the grenade 1 and to a frame connector 51 of the electric detonator. The firing pin switch 30 is a switch which, as the intermediate firing pin 96 moves when the firing pin of a weapon equipped with a firing pin strikes on it, switches the control unit 90 to operation.

[0022] Figures 2B and 2C illustrate the placement of the connectors in the support member 8 and the grenade 1. In Figure 2B, current conductors and the connectors 94 and 95 are provided in the support member 8 such that a contact with the electric detonator 5 and the frame connection 51 shown in Figure 2C is produced during attachment of the support member 8. Herein, the connector 95 of the electric detonator is placed in the centre of the support member 8 while the connector 94 of the frame connection of the electric detonator is placed on the outer periphery in the vicinity of the attacment members 80. The current source 20 of the support member is formed from four batteries located in the support member, which may be placed at the bottom of the support member 8 and covered by a protective cover 25. The current source may be made up even from ordinary AA or AAA batteries which, when coupled in series, form a 6V voltage source. Of course, depending on the electronics used, a smaller voltage may also be used and, respectively, depending on the voltage of the batteries used, the number of batteries may also differ.

[0023] Figure 2C is a rear view showing a grenade 1. The grenade is provided with guide wings 4. The electric detonator 5 of the charge of the grenade is located on the centre axis of the rear surface of the tail barrel of the grenade. The frame connection 51 of the electric detonator is circular. In such a case, the connection is implemented between the connector 94 in the support member and the frame connection 51 in the ammunition, independently of the axial location of the grenade. This is a preferred embodiment in solutions wherein the attachment of the ammunition to the support member is implemented by turning the parts with respect to one another.

[0024] Figure 3A shows a launching situation of a grenade attached to the support member according to Figure 2A. The grenade 1 is attached to the support member 8 such that the launching means 9 are via the connectors 94 and 95 connected with the electric detonator 5 of the charge of the grenade and the frame connector 51 of the electric detonator.

[0025] A firing pin 10 of the weapon has pushed the intermediate firing pin 96 toward the current source 20. The locking member 97 in connection with the intermediate firing pin has broken down or bent due to the force of the firing pin such that the intermediate firing pin 96 has succeeded in striking on the firing pin switch 30.

[0026] The current circuit closes in the support member such that the current source 20 charges the capacitor 40. The control unit 90 identifies the charge situation of the capacitor 40 and controls the charge of the capacitor 40 via the connectors 94, 95 to the detonator 5 of the grenade 1 , which launches a basic charge of the grenade 1. The time taken by the launch of the ammunition varies according to the current source, but it may be e.g. of the order of 60 to 90 ms, which is considerably faster than in a solution using a current source only.

[0027] Figure 4 schematically shows a circuit diagram of the control unit 90 of the support member and related peripheral devices of the launching means. After the firing pin of the weapon has struck, the activation switch, i.e. the firing pin switch 30, closes and switches the current source 20 to feed current to the capacitor 40 which is capable of discharging its charged-up energy in a considerably shorter period of time than mere batteries, whereby the launching delay becomes shorter. The capacitor thus enables sufficient peak energy to be obtained within a short period of time for launching the electric detonator. The current source 20 increases the pole voltage of the capacitor 40 via a voltage booster 72. The voltage booster 72 may be e.g. a chopper wherein output voltage is higher than input voltage. [0028] The control circuit 91 , such as a microcontroller, receives from the current source 20 a supply voltage which is adapted according to the microcontroller by a unit 71 wherein the output voltage may be smaller than the supply voltage.

[0029] The microcontroller 91 is provided with inputs 94 and 95 connected thereto to enable the charge situation of the capacitor to be established. The microcontroller 91 may also be provided with inputs to receive e.g. a signal from the reception means 21 , 21 A, 22, 22A shown in Figures 5A and 6.

[0030] The control unit follows the charge situation of the capacitor and switches outputs 97 and 98 in order to produce a desired control event. Activation of the output 97 provides control voltage to a lower semiconductor switch 92 which, in turn, switches an upper semiconductor switch 92 which allows the charge of the capacitor 40 to be discharged to the electric detonator 5. Here, the lower semiconductor switch 92 is of the n-MOSFET (Metal-oxide- semiconductor field-effect transistor) type and the upper semiconductor is of the p-MOSFET type. The control voltage of the output 97 of the microcontroller controls, via the n-MOSFET, the gate of the p-MOSFET to ground. In such a case, the electric energy charged in the capacitor 40 discharges to the contacts of the electric detonator and the detonator ignites.

[0031] If this does not happen, the microcontroller 91 may retry the same with a longer charging time of the capacitor 40. Regharging is a procedure implemented by the microcontroller, which is possible to program in the program memory of the microcontroller. It is possibly to use a longer charging time of the capacitor 40 in the next try.

[0032] If the electric detonator 5 is not launched despite one or more retries, the launching unit may be transferred to a safety state. This means that the microcontroller short-circuits the poles of the capacitor 40 to the current limiting resistor by feeding via the output 98 a control voltage to a semiconductor switch of a unit 93. In addition to this, the control unit may prevent its own operation, in which case the launch of the detonator is prevented by the support member in question. The operation time of the sequence according to the diagram from the stroke of the firing pin to the discharge of the charge of the capacitor takes, in estimation, about 60 to 90 ms.

[0033] The support member may possibly be provided with an activation switch which starts charging the capacitor prior to a stroke of the firing pin. In such a case, the firing pin switch 30 is located in the circuit after the capacitor 40. The operation time of the sequence from the striking of the intermediate firing pin to the discharge of the charge of the capacitor then takes, in estimation, about 5 to 10 ms.

[0034] The semiconductor switches 92 and 93 per se may be of any suitable type, such as MOSFET, JFET or another suitable semiconductor. Instead of a semiconductor, mechanical electrically controlled switches, such as various relays, may of course also be used. Similarly, different switches may differ in type, in which case one may be e.g. a semiconductor switch and another may be a mechanical switch. Naturally, the control of the switches is in accordance with the technology of the switches.

[0035] Figure 5A shows a second embodiment of the support member according to the invention. Herein, the support member 8 is attachable by turning the grenade and the support member with respect to one another. The outer surface of the tail barrel 3 of the grenade is provided with threads which upon turning become attached to the threads provided in an inner surface 81 of the attachment member 80 of the support member 8. It is clear that the launching means 9 according to the invention may be provided in support members 8 equipped with different attachment means 80.

[0036] The support member is provided with reception means 21 , 22 for receiving current fed by a current source located outside the support member 8. The reception means 21 and 22 of the support member may possibly also be an induction ring arranged to receive current from a current source which is located outside the support member and which conveys current according to an electromagnetic induction principle.

[0037] Figure 5B is a side view showing the support member of Figure 5A. The first one 21 of the reception means is located in the edge collar 87 and the second reception means 22 is located on the outer surface of the edge collar of the support member 8.

[0038] Figure 6 shows a third embodiment of a support member according to the invention. It illustrates a solution wherein no intermediate firing pin is used. The firing pin of a weapon penetrates through the rear surface of the support member or presses the rear surface forward towards the grenade such that an impulse is directed at the firing pin switch 30.

[0039] The rear surface 86 of the support member 8 is provided with a locking member 97 which, after the firing pin has stricken on the support member 8, yields such that the firing pin is allowed to strike on the firing pin switch 30. The locking member 97 may be formed such that no knocks or drops or the like cause the weapon to be launched. The operation of the locking member 97 may also be influenced by varying the wall thickness of the base of the support member 8. By means of such an embodiment, the launching means 9 may be formed in a smaller space. The number of necessary parts also decreases. In this embodiment, the reception means 21 A and 22A located on the outer surface of the support member 8 may be used as safety means to identify that the support member has been positioned in the barrel of the weapon. This may be implemented e.g. such that the reception means 21A and 22A are included into the microcontroller as one launch criterion. It is clear that the reception means 21 A and 22A and their operation may also be included in the embodiments shown in Figures 2A and 5B.

[0040] It is apparent to one skilled in the art that as technology advances, the basic idea of the invention may be implemented in many different ways. The invention and its embodiments are thus not restricted to the above- described examples but may vary within the scope of the claims.

Claims

1. A support member for launching ammunition from a barrel of a breech-loading weapon, which support member (8) keeps the ammunition (1) in place in the barrel prior to its launching and comprises means for attaching the support member (8) to a rear end of the ammunition (1) such that the means become detached from the ammunition (1) or break down upon launching, the support member (8) comprising means for launching a charge of the ammunition (1) due to the influence of a stroke of a firing pin of the weapon, characterized in that it comprises launching means (9) for launching an electric detonator (5) of the charge, the launching means (9) comprising a capacitor (40), a control unit (90) provided with comparison means (94, 95) for monitoring a state/charge level of the capacitor, switch means for conveying charge charged in the capacitor (40) to the electric detonator (5) of the charge of the ammunition, and a firing pin switch (30) which, due to the influence of the stroke of the firing pin of the weapon, controls the switch means to convey the charge to the electric detonator (5) of the charge of the ammunition.

2. A support member as claimed in claim ^ characterized in that the switch means comprise at least one semiconductor switch (92).

3. A support member as claimed in claim 1 or 2, characterize d in that the launching means (9) of the support member further comprise a current source (20) for feeding current to the capacitor (40).

4. A support member as claimed in claim 3, characterized in that the current source (20) is formed from one or more batteries located in the support member (8).

5. A support member as claimed in any one of the preceding claims, characterized in that the support member is provided with reception means (21, 22; 21 A, 22A) for connecting to a device positioned substantially outside the support member (8).

6. A support member as claimed in claim 1 or 2, characterized in that the support member is provided with reception means (21, 22) for receiving current fed by a current source (20) located outside the support member (8).

7. A support member as claimed in claim 6, c h a r a c t e r i z e d in that the reception means (21 , 22) is an induction ring arranged to receive current from a current source which is located outside the support member and which conveys current according to an electromagnetic induction principle.

8. A support member as claimed in any one of the preceding claims, c h a r a c t e r i z e d in that the support member is provided with an intermediate firing pin (96) for launching the charge of the ammunition in a weapon equipped with a firing pin, whereby the firing pin of the weapon strikes on the intermediate firing pin (96) in order to launch the charge, bringing it to a striking movement, and that the firing pin switch (30) for launching the electric detonator (5) is installed to operate due to the influence of the striking movement of the intermediate firing pin (96).

9. A method of launching ammunition from a barrel of a breech- loading weapon, the method comprising launching the ammunition (1 ) by means of a support member which is to be attached to a rear end of the ammunition and which keeps the ammunition (1 ) in place in the barrel prior to its launching, the support member comprising means for attaching the support member to the rear end of the ammunition (1 ) such that the means become detached from the ammunition or break down upon launching, as well as means for launching a charge of the ammunition (1 ) due to the influence of a stroke of a firing pin of the weapon, c h a r a c t e r i z e d by the method comprising, in order to launch the charge equipped with an electric detonator, a) performing, due to the influence of the stroke of the firing pin of the weapon, a switching procedure in a current circuit, b) feeding current to a capacitor (40) of the launching means (9), c) receiving information on a charge level of the capacitor (40) by a control unit (90), d) comparing, at the control unit (90), the information on the charge level of the capacitor (40) with a predetermined level, and e) upon the charge level of the capacitor (40) reaching the predetermined charge level, performing by the control unit (90) a switching procedure activating at least one switch (92) in order to convey the charge charged in the capacitor (40) to the electric detonator (5) of the charge of the ammunition.

10. A method as claimed in claim 9, c h a r a c t e r i z e d by the method further comprising repeating b) to e) at least once if e) does not lead to a launch of the electric detonator (5) of the charge of the ammunition.

11. A method as claimed in claim 9 or 10, ch a racterized by the method further comprising f) performing by the control unit (90) a switching procedure activating at least one switch (93) in order to short-circuit the capacitor via a current limiting resistor if e) does not lead to the lauch of the ammunition.

12. A method as claimed in any one of claims 9 to 11, ch a racterized by a semiconductor switch being used as at least one of the switches (92; 93).

13. A method as claimed in any one of claims 9 to 12, ch a racterized by the method further comprising g) transferring the control unit (90) to a state which prevents launching.