IL101607A

IL101607A - Safety arrangement of projectile fuse

Info

Publication number: IL101607A
Application number: IL10160792A
Authority: IL
Original assignee: Junghans Gmbh Geb
Priority date: 1991-04-20
Filing date: 1992-04-16
Publication date: 1994-05-30
Also published as: DE4112960A1; EP0510396A3; IL101607A0; DE4112960C2; MY131302A; KR920020184A; EP0510396A2; JPH0587499A

Description

/90/82 101607/2 SAFETY ARRANGEMENT FOR PROJECTILE FUSE The invention relates to a safety arrangement for a projectile fuse as set forth in the classifying portion of claim 1.

German published specification (DE-AS) No 10 65 758 already describes a safety arrangement in a projectile fuse, wherein a slider is displaceable, supported by a spring, in a rotor within a radially extending groove. The slider has an upper and a lower portion and carries an igniter pellet or capsule and, on the same axis, a transmission pellet or capsule, both of which are movable into the detonating channel of the projectile fuse. In the case of a fuse delay arrangement, a third slider with a delay pellet or capsule is provided between the two slider portions with the igniter pellet or capsule and the transmission pellet or capsule, so that then a continuous detonator chain is formed.

Both DE 31 07 110 C2 and DE 31 08 659 C2 disclose safety arrangements for fuses, in which what is known as a shoot-back pin system is used within a rotor. The shoot-back pin system essentially comprises two pins which are arranged parallel to each other and between which a ball is mounted.

When a projectile with that safety arrangement is fired, the translatory acceleration which acts on one of the two pins pushes the ball against a cone portion of the other pin. By virtue of a spring used in that arrangement, the shoot-back pin system is arrested in the released or activated position by way of the cone portion, the ball and a cylindrical surface on the pin. In that way the rotor is unlocked by that pin.

Taking the above-indicated state of the art as the basic starting point, the object of the invention is to provide a safety arrangement for a projectile or shell fuse of the kind set forth in the opening part of this specification, in which the degree of detonator safety is improved and the shoot-back pin system which is known from the state of the art is further simplified.

In accordance with the invention that object is attained by the characterising features of claim 1.

Configurations of the invention and further developments in the basic concept thereof are set forth in claims 2 to 6.

The advantages of this safety arrangement are that the rotor is of a three-part configuration and at the same time also represents the second safety member. More specifically the rotor shaft also serves at the same time as an arresting means in the live or armed position. The free space beneath the rotor in the housing improves the level of detonator safety in the safe condition. As a function of the shoot-back pin system is taken over by the rotor or the rotor shaft, this safety arrangement does not require the second pin, which is otherwise necessary, of the shoot-back pin system.

Details of the invention will be described in greater detail hereinafter by means of an embodiment. In the drawings: Figure 1 is a sectional view of a safety arrangement in a mortar impact fuse, Figure 2 is a plan view of the safety arrangement viewed along line II-II in Figure 1, Figure 3 is a view in section through the safety arrangement taken along line III-III in Figure 2, Figure 4 is a plan view of the safety arrangement of the fuse without fuse delay, Figure 5 is a plan view of the safety arrangement of the fuse with fuse delay, and Figure 6 is a view in section of the rotor illustrating the position for the fuse delay.

The fuse which is shown in the form of a mortar impact fuse essentially comprises a housing 1 in which a rotor 4 is mounted rotatably about the central axis or shaft 7 of the rotor, and the housing cover 30 which is fitted on to the housing 1. A sealing ring 32 is fitted between the housing 1 and the housing cover 30. The safety pin 27 for securing the rotor 4 can be seen on the housing 1 on the outside thereof, being held in the safe position by means of a rubber ring 28.

The fuse as illustrated in Figure 1 is in the armed or live position so that, axially beneath the firing pin 29, the igniter portion 5, the delay charge 11 and the detonator 6 form a continuous detonator chain to the first detonator means 2 and the detonator booster. Reference numeral 33 shows the timer mechanism for rotating the rotor 4 into its armed or live position.

Figure 2 shows a plan view of the mechanism 33 and the rotor 4.

In that respect, in Figure 2 the fuse is in the safety position, as can be seen from the position of the detonator portion 5 which is pivoted out of the axis of the firing pin. That safety position of the fuse is shown in section in Figure 3. The rotor 4 and the mechanism 33 are disposed in a rotor housing 9 which is fitted into a suitable recess in the fuse housing 1. The rotor 4 itself comprises three e fig. 6) which are arranged axially one above the other, of which the upper disc 4.1 carries thr. igniter portion 5, the middle disc 4.2 carries the delay charge 11 end the lower disc 4.3 has the detonator 6. The upper disc 4.1 and the lower disc 4.3 are opera ively connected together end rotate simultaneously while the middle disc 4.2 with the delay charge 11 is movable relative to the upper disc 4.1 and the lower disc 4.3. The delay charge 11 in the middle disc 4.2 is only pivoted when necessary into the firing chain between the igniter portion 5 and the detonator 6. In the safety position of the fuse as shown in Figure 3 the upper disc 4.1 of the rotor 4 is in driving connection with the output drive gear 34 of the mechanism 33. In that situation the individual discs of the rotor 4 are in an upper position, whereby there is a free space 10 beneath the lower disc 4.3, relative to the bottom 9.1 of the rotor housing 9.

The free space 10 provides a detonator safety aspect in the safe condition as the first detonator means 2 is still disposed beneath the bottom 9.1 of the rotor housing 9.

The central shaft or axis 7 of the rotor has two grooves 12 and 13 which are disposed in an annular configuration in superposed relationship, of which the upper annular groove 12 is arranged in the region of the upper disc 4.1 in the safe position. In that situation the annular groove 12 is connected to a locking element 8 which is illustrated in the form of a pin which is disposed in a transverse bore and bears against a pin 3 which is arranged parallel to the central axis 7 of the rotor. The pin 3 bears with a flange surface 14 axially against the upper disc 4.1 beneath same, while bearing against the flange surface 14 is a coil compression spring 18 which is supported in a bore in the lower disc 4.3 of the rotor 4. In its top part, after a cone portion 16, the pin 3 has a projection portion 17 projecting into a bore in the housing cover 35 of the rotor.

When the spin-free or low-spin projectile with the above-described fuse is fired, due to the firing acceleration effect the pin 3 moves downwardly against the force of the coil compression spring 18 so that finally the locking element 8 moves radially outwardly until it comes to bear against the projection portion 17.

When that happens, the locking element 8 cones out of engagement with the annular groove 12 in the central shaft or axis 7 of the rotor. That means that the discs 4.1, 4.2 and 4.3 of the rotor 4 are displaced axially downwardly in the direction of the bottom 9.1 of the rotor housing 9. The free space 10 is eliminated as a result. That is the position that can be seen in Figure 1. In the lower position, the locking element 8 moves radially back again and engages into the annular groove 13 in the central shaft or axis 7 of the rotor. At the same time the locking element 8 comes to bear against the outside diameter of the pin 3 again, when the spring 18 has extended again.

During the axial downward movement of the rotor 4, the upper disc 4.1 and jointly therewith the lower disc 4.3 have moved from the position shown in Figure 2 into the position shown in Figure 4. That rotary movement of the rotor 4 is produced by the pin 19 which projects radially from the rotor 4 and is deflected into a radial movement during the axial movement, by way of a control cam in the wall of the rotor housing 9. The igniter portion 5 is disposed in a detonator chain with the detonator 6 on the line of action of the firing pin 29. The first detonator means 2 and the detonator booster 31 in the fuse housing 1 are now disposed directly beneath the detonator 6. The delay charge 11 with the middle disc 4.2 has not been pivoted into the detonator chain. The control cam for engagement of the pin 19 is disposed at 20.

If the delay charge ll in the middle disc 4.2 is to be pivoted into the detonator chain, jointly with the upper disc 4.1, it is necessary for the middle disc 4.2 to be locked to the upper disc 4.1. That is effected by a securing pin 21 which projects radially out of the middle disc 4.2 bearing against a control cam 25 on the rotor housing 9. In that way the pin 21 is urged radially inwardly in a direction towards the central shaft or axis 7 of the rotor, against the force of the spring 22. In that position the securing ball 24 lies in the annular groove 23 in the pin 21. If the pin 21 comes out of engagement with the control cam 25, the pin 21 is moved radially outwardly under the force of the spring 22. The ball 24 as a securing element is urged out of the annular groove 23 and passes into a locking position with the upper disc 4.1 of the rotor 4, as shown in Figure 6.

Figure 5 shows the fuse in the released or activated position with the delay charge 11 pivoted into position.

Claims

101607/2 - 7 - CLAIMS :

1. A safety arrangement for a projectile fuse having a first detonator means (2) in a housing (1) on which a rotor (4) is mounted, and a second detonator means comprising an igniter portion (5) and a detonator (6) which is movable over the first detonator means (2) to form a detonator chain, and a delay charge (11) which is movable into the detonator chain, characterised in that provided at a radial spacing relative to the central axis (7) of the rotor (4) and parallel thereto is a pin (3) which is subjected to the force of a spring and the central axis (7) is operatively connected to the pin (3) by a locking element (8), and that in the safe position there is between the rotor (4) and the bottom (9.1) of a rotor housing (9) a free space (10) which in the armed position of the projectile fuse is filled by the rotor (4) which moves axially and rotates about the central axis (7), to form detonator chain .

2. A safety arrangement according to claim 1 characterised in the central axis (7) of the rotor (4) has two axially spaced-apart annular grooves (12,13) into which the locking element (8) engages in the released and in the armed positions, the locking element bearing at one end against the peripheral surface of the pin (3) which bears with a shoulder (14) against an axial rotor surface (15) and at the top end, above a cone portion (16), has a projectile portion (17) of reduced diameter.

3. A safety arrangement according to claim 1 of claim 2 characterised in that the rotor (4) comprises three axially superposed discs (4.1, 4.2, 4.3) and the pin (3) like also the locking element (8) is fitted in an axially upward disc (4.1) while the spring (18) which supports the pin (3) is supported on or in an axially lower disc (4.3), while the igniter portion (5) is disposed in the axially upward disc (4.1), the delay charge (11) is disposed in the middle disc 101607/2 - 8 - (4.2) which is movable relative to the upward and lower discs, and the detonator (6) is disposed in the lower disc (4.3) in parallel-axis relationship with respect to the igniter portion ( 5 ) .

4. A safety arrangement according to claim 3 characterised in that fitted into the upper disc (4.1) of the rotor (4) is a radially projecting pin (19) whose projecting end slides over an axially oriented control cam (20) of the housing (1).

5. A safety arrangement according to claim 3 characterised in that fitted into the middle disc (4.2) of the rotor (4) is a radially projecting securing pin (21) which is subjected to a spring force and whose projecting end slides over a radially oriented control cam (25) of the housing (1) and thereby releases ball-pin securing means between the upper disc (4.1) and the middle disc (4.2), the projecting end of the securing pin (21) in the armed position bearing radially against a fixed abutment (26) of the housing, thereby forming the detonating chain with delay charge (11) incorporated therein.

6. A safety arrangement according to claim 1 further characterised in that a safety pin (27) which renders the projectile fuse safe is held by a ring (28) of plastic material, preferably natural rubber, which is provided with a gripping surface, the ring being applied against the outside surface of the housing (1). ATTORNEYS FOR APPLICANTS