IL100923A - Percussion ignition device for a mortar or the like and a mortar comprising such a device - Google Patents

Description

nan iK nmnn nay ne a »*τ* 5j> nnxn ipnn PERCUSSION IGNITION DEVICE FOR A MORTAR OR THE LIKE AND A MORTAR COMPRISING SUCH A DEVICE The invention concerns a firing mechanism by percussion for a mortar or similar weapon, and a mortar or sim lar weapon incorporating such a mechanism.

Apart from muzzle-loading mortars, there are also known to exist mortars loaded from the rear, whether from a drum-type magazine of shells, as described in FR-A-2 402 852, or from a loading chamber being moved perpendicularly to the axis of the discharge tube as described, for example, in FR-A-2 163 932. While the usual muzzle-load ng mortars are equipped with a firing mechanism which simply consists of a fixed firing-pin rigidly fixed to the baseplate of the weapon, this approach is obviously unsuitable for the advanced mortars of the types described in the aforesaid documents, nor generally for rea»—loading mortars, in which one part of the discharge tube that serves as a shell carrier is to be displaced relative to the discharge tube proper.

The problem thus arises of providing such mortars with a firing mechanism using mechanical percussion which would be at once reliable, capable of containing the pressure of the propel! ant gas upon discharge, and also capable of withstanding the recoil acceleration in the case of weapons equipped with means for absorbing this recoil and, finally, enabling automatic reloading upon the countei—recoil of the weapon as required, in particular, for rapid-fire mortars.

The basic problem of the invention is solved by means of a percussion-firing mechanism for a mortar or similar weapon compr sing a mobile firing-pin mounted on a translation carriage and means of activating this pin, so that the said pin forms a part of a percussion assembly housed in a body rigidly affixed to the rear baseplate of the mortar and which is activated by a trigger releasing a percussion spring with an interposed articulated sear on which pivots an arm which may be engaged, on the one hand, with the activating organ associated with the trigger and, on the other hand, with a movable stop assembly also rigidly affixed to the rear baseplate of the mortar and which should be engaged with a fixed organ of the said mortar.

According to another characteristic of the invention, the trigger is a solenoid with a rod engaging with the activation organ which comprises a push-rod loaded by the return spring and having its extremity adjacent to the solenoid rod consisting of a rocking mechanism mounted so as to pivot around an axis essentially perpendicular to the striker sliding runout.

In a preferred realization the percussion assembly consists of the following: - The firing-pin proper, of circular cross-section, split into longitudinal channels movable along the first bore provided in the body affixed to the rear baseplate of the mortar; - A piston of the same axis as the firing-pin, housed in the second bore of the said body and forming one piece with the firing-pin, these two being connected by a sealed rod that fits in the ring separating the first from the second bore; - A percussion spring pressing, on one hand, on -the piston •face opposed -to the face turned towards the f1r1ng-p1n proper and, on the other hand, against a* threaded plug which forms the said second bore; and - The said second bore containing shock absorbing spring means o which the pre-stress may be adjusted by way of the threaded plug and which are Intended to be engaged by the said piston.

The invention also includes the articulated lever having one of its extremities on the connecting rod that joins the firing-pin proper with the piston which is similarly articulated at Its other extremity along the guiding jaws of the body rigidly affixed to the rear baseplate of the mortar.

- The latter also carries the mobile stop assembly consisting of an arming pin mounted so as to slide against the action of a compression spring having its tension adjustable by means of an adjusting screw on which the articulated arm pivoted on the lever connected to the percussion assembly is intended to be supported.

According to yet another characteristic of the invention, the said articulated arm fits into the bore which slides the push-rod and which 1s mounted on the body rigidly affixed to the rear baseplate of the mortar 1n which the percussion assembly is mounted.

The Invention 1s covered by the following description, based on the example and referring to the drawings appended, in which: - figure 1 1s a view of the mechanism according to the Invention 1n the Initial state, before a shot 1s discharged; - figure 2 shows the corresponding view- but after the discharge of a shot; - figure 3 shows a view similar to that of figure 2 but for another state of the mechanism; - figure 4 shows a detail; - figure 5 shows the section 5 - 5 marked on figure 2, but on a larger scale.

A mechanism D according to the Invention, for firing a shell p_ i from a mortar M, 1n which t Indicates the rear extremity of the discharge tubexT - opposed to the muzzle a - and which 1s of one piece with the rest of the tube or, more generally, movable relative to the said discharge tube T, consists essentially of the percussion assembly pin, the mobile stop assembly 11, the means of activation 12 of the percussion assembly 10 and the activation organ 13 of the means 12 which is operated with the aid of the trigger consisting in this case of the solenoid 16 and the rod 17.

The percussion assembly 10 is housed in the body 23 fixed to the rear baseplate 27 of the mortar and, by virtue of this fact, shares the recoil movement of the weapon when it is fired, in as much as this recoil 1s manifested. As 1s plainly seen 1n figures 1 and 3, the body 23 1s provided in its -front tubular part, 23b, with a first bore 23a in which is mounted a sliding fir1ng-p1n 24 having its front face 24a provided with the percussion point 24b, the circular cross-section of the firing-pin being as shown in figure 5, that is, circular and sliced into 4 longitudinal channels 25 , 25 , 25 , and 25 equally 1 2 3 4 distributed 'over the circumference and which stretch over the entire length of the fir1ng-p1n which 1s affixed on the rod 26 coaxial with the axis A of the tube T.. The rod 26, which carries the 'piston 30, slides near the rear extremity of the bore 23a in a sealing and guiding ring 18, mounted in the facing 31 of the part 23b of the body 23 and which presses against the shoulder 32 of the said part. On the face piston 30, opposed to the face turned toward the firing-pin 24, presses the percussion spring 33 which encircles the part of largest diameter of 26a of the rod 26 which passes through the threaded plug 35 at the rear extremity of the body 23 and having Its end 35a coming out through the stop of the spring 33. The latter is in part encircled by the ring 40 resting on the shoulder 41 of a second bore 42 - of larger diameter than the bore 23a - provided in the rear part of the body 23, said ring 40 serving to guide as well as to stop by piling up the shock-absorbing springs 45 whose pre-stressed state may be adjusted with the help of the threaded plug 35, which in part caps the ring 40 by its cylindrical-end surface 46. At the rear extremity of the rod 26a there is mounted an articulated lever 51 on the pivot 50, which lever is also articulated at its other extremity on the pivot 52 mounted in the jaws J which support the body 23 and between which the arm 54 may be displaced as 1t swings on the lever 51 around the pivot 53 located between the pivots 50 and 52, this arm 51 being guided in the opening 55 of the bore 56 set up on the body 23 and directed essentially perpendicu arly to the axis of the bores 23a and 42, being positioned about halfway along the latter.

Within the bore 56 1s mounted 1n sliding fit the pushrod 60 of which the extremity 60a (the extremity nearest the body 23) 1s hollowed to accept the compression spring 61, figure 3, that presses at its other extremity against the bottom of the bore 56, the push-rod 60 carrying at Its other extremity . a rocking mechanism 62 consisting of a tab 63 swinging on the pivot 64 against the action of the piano-wire spring 65, figure 4.

Apart from the percussion assembly 10, the means 12 and the organ 13 already described, the mechanism D also comprises the mobile stop assembly 11 consisting of an arming pin 70 mounted 1n sliding fit 1n the baseplate 27 of the mortar and on which is exerted the action of the compression spring 71 housed in the recess 72 of the said baseplate 27, which recess 1s blocked over the rear face of the baseplate 27 by a nut 73 engaged by the adjustment screw 75 which is also engaged with a counter-nut 76 serving to adjust the retraction of the firing-pin 24. A fixed plate 80, provided in front of the mobile stop assembly 1s Intended to engage the arming pin 70 in order to draw the latter, against the action of the spring 71, from its position Indicated 1n figure 3 to that indicated in figures 1 and 2, as is explained 1n detail 1n the following description of the functioning of the mechanism according to the present invention.

In its initial condition, the firing mechanism is as shown in figure 1, the fir1ng-p1n 24 1s Inside the* bore 23a, the percussion point 24b does .not extend into the tube T- into which the shell p has been introduced. When the solenoid 16, bolted to a fixed part of the weapon, 1s actuated, its rod 7 is freed to pass over from the state shown 1n figure 1 to that shown in figure 2 in which 1t presses against the tab 63 and displaces the push-rod 60 in the direction of the arrow F, causing the arm 54 to swing downwards (1n the figure), this arm having been in contact with the screw 75 and with the mobile stop assembly 11, and which now releases them. The percussion spring 33, which was cocked in the initial state, 1s now released and kicks forward the firing-pin 24 through the Intermediary of the rod 26 which 1s Joined to 1t.

The primer of the cartridge with which the shell β is equipped then ignites the charge or charges c associated with the shell p_ which as they burn generate the gas which propels the said shell. This propellant gas, confined between the walls of the tube J, the baseplate 27 of the mortar and the shell causes the latter to be ejected, on the one hand, and on the other hand, penetrates in part, passing through the channels 25, into the chamber formed by the bore 23a, the rear face of the firing-pin 24 and the sealing ring 18, which should preferably be a ring with a Hp made of corrosion-resistant material, for example such as the materials used 1n valve-guides of motorcar engines.

In case the shell £ carries a reduced charge c, then whatever the propel lant cartridge, the pressure of the gas generated is low and the weapon does not recoil, or only slightly; the pressure force exerted on the front face 24a of the firing-pin 24 1s then higher than that exerted on the rear face of the said firing pin, this being due to the presence of the rod 26, so that the firing pin and the rod joined to 1t recoil from the position shown in figure 2, and compress the percussion spring 33. The lever 51 turns on the pivot 52 in counter-clockwise sense, as shown by the arrow f, thus freeing the arm 54 from the screw 75 of the mobile stop assembly, whereas the spring 61 placed under tension at the release of the solenoid (Its rod having been retracted meanwhile) now brings back the arm 54 to press against the screw 75, that 1s, returns it again to the state shown 1n figure 1, so that the next munition may be fired.

In the opposite case, if the munition or shell £ is equipped with a high charge c, then upon firing as described, the propel lant gas generated exerts a high pressure which causes, on the one hand, a recoil of the weapon, as shown 1n figure 3, but also, on the other hand, a displacement of the rod 26 and of the piston 30 joined to 1t. The displacement is of greater amplitude than in the preceding case, and it brings the said piston to press upon the ring 40 and to slightly displace the latter, compressing the shock-absorbing springs 45 and thus dissipating and absorbing some of the kinetic energy of the percussion assembly, of the lever 51 and of the arm 54 associated with it. When the propel!ant gas pressure has diminished sufficiently, the compression spring 33, on the one hand, and the shock-absorbing springs 45, on the other hand* return the percussion assembly, the lever 51 and the arm 54 to the position . shown 1n figure 3 whereby the firing-pin 24 protrudes Into the firing chamber of the discharged tube T . Upon recoil, the -pin 70 of the mobile stop assembly 11 which is no longer arrested by the plate 80, is displaced forwards, under the action of the spring 71, taking the adjustment screw 75 out of reach of the arm 54 which 1s therefore essentially aligned with the pin 70, that is, it assumes the position s«»own in figure 3 to which it was brought by the push rod 60 - which at the start of recoil escaped the rod 17 of the solenoid 16 - and which is thus subject to the action of the spring 61, previously placed under tension, as explained In the aforesaid, upon firing the shot.

Whereupon, starting from the state shown in figure 3 - which 1s the state obtaining at the end of the recoil stage and when the counter-recoil is about to start - the entire mobile assembly is once more displaced forwards (under the action of means not shown and which are associated with the mortar) the pin 70 comes to rest against the fixed plate 80 and then said pin 1s displaced 1n a sliding motion towards the rear of the weapon to cause, the corresponding motion of the arm 54: the latter then swings on the pivot 52 and on the pivot 50 to retract the fir1ng-p1n 24 into its hidden state, simultaneously compressing the percussion spring 33. The state obtained is once more the one shown in figure 1, in which the weapon is ready to fire the next munition, whether the latter is provided with a strong or a weak propelling charge, so that the mechanism D according to the invention operates, as explained in the aforegoing, ndependently of the amount of charge ut lized, that is, whether it is strong, weak, and even when the weapon does not recoil at all.

Other factors that contribute to the proper functioning of the mechanism according to the invention are the fact that the tab 63 is mounted at the extremity of the push rod 60 by means of a rocking mechanism which, as shown in figure 4, permits the said push rod, and consequently the entire mechan sm, to regain the armed position, even in case the rod 17 of the solenoid has not been retracted into its inoperative state at the end of the counte»—recoil, and this is achieved very simply by the swinging movement on the pivot 64 against the action of the spring 65 with the result that the tab is returned to its state permitting another shot to be fired. 100923/2

Claims (7)

1. A percussion firing mechanism for a mortar or analog weapon comprising a mobile firing-pin capable of tranSlatery motion and activating a means of said firing-pin, characterized in that said firing-pin (24) forms a part of a percussion assembly (10) housed in a body (23) rigidly fixed to a baseplate (27) of the mortar (M) and which is activated by a trigger (16) releasing a percussion spring (33) with an interposed pivoting lever (51) on which is fitted a pivoted arm (54) intended to engage, on the one hand, an actuation organ (13) associated with the trigger (16) and, on the other hand, a mobile stop assembly (11) also fixed to the rear baseplate (27) of the mortar (M) and which is intended to engage a fixed organ (80) of the said mortar.

2. Mechanism according to Claim 1, characterized in that the trigger is a solenoid (16) of which the rod (17) should engage an activating organ (13) consisting of a push rod (60) o which is exerted the action of the returning spring (61) and which has its extremity adjacent to the rod (17) of the solenoid (16) carrying a rocking mechanism (63) mounted on a pivot (64) essentially perpendicular to the axis of sliding of the push rod.

3. Mechanism according to Claim 1 or according to Claim 2, characterized in that the percussion assembly consists of the following: 100923/3 - A firing-pin (24) proper, of circular cross-section* divided by means of longitudinal channels (25) and movable within a first bore in the body fixed on the rear baseplate of the mortar; - A piston (30) having the same axis as the firing-pin (24 housed in a second bore (23a) of the said body and joined to the firing-pin by a rod (26) guided by the sealing ring (18) which separates the first from the second bore; A percussion spring (33) which presses, on the One hand, on the face of the piston (30) opposed to the face turned towards the firing-pin proper and, on the other hand* against a threaded plug (35) which closes the said second borej and Having within the said second bore (42) means consisting of a shock-absorbing spring (45) of pre-stress which may be adjusted by means of the threaded plug (35) and which is intended to engage said piston.

4. Mechanism according to afiy of the above Claims characterized in that the pivoting lever (51) articulated at one of its extremities with an extension rod (26a) of the rod (26), and which rod (26) joins the firing in proper (24) with the p ston (30) is also articulated at its other extremity at the jaws (0) bearing the body mounted rigidly on the rear baseplate (27) of the mortar (M). j

5. Mechanism according to Claim 1, characterized in that the mobile stop assembly (11) consists of an arming pin (70) mounted so as to slide within the baseplate (27) of the mortar (M) against the action of a compression spring (71) and an adjustment screw (75) intended to support the arm (54) articulated over the pivoting lever (51) that is connected to the percussion assembly (10).

6. Mechanism according to one of the above Claims, characterized in that the arm (54) articulated over the lever (51) is guided 1n the opening (55) of a bore (56) in which slides the push-rod (60) and which is fixed on top of the body (23) in which the percussion assembly (10) is mounted.

7. Mortar or similar weapon, characterized in that 1t Incorporates a percussion-firing mechanism according to one of the above claims. C: B7505