ZA200708509B

ZA200708509B - Fuze for a projectile

Info

Publication number: ZA200708509B
Application number: ZA200708509A
Authority: ZA
Inventors: Zinell Alexander; Pannhorst Johann
Original assignee: Junghans Microtech Gmbh
Priority date: 2006-10-07
Filing date: 2007-10-05
Publication date: 2008-10-29
Also published as: EP1909056A1; US20080210115A1; DE102006047549A1; DE102006047549B4

Description

oo — , &.20077 08509 ll I . | FUZE FOR A PROJECTILE

Field of the Invention

This invention relates to a fuze for a projectile and, in particular, to fuze for a projectile that does not spin.

Background to the Invention ;

In the case of projectiles that do not spin, such as mortars or the like, the launch acceleration is used as a first arming criterion. A safety break, for example, is used as a second arming criterion, which must be withdrawn before the projectile is launched. A safety break such as this has the serious defect that the fuze of the projectile has only one safety feature once the safety break has been withdrawn, and nevertheless still has to be handled. This results in an increased risk to the operator. Furthermore, safety breaks such as these are not suitable for automatic weapons or launch systems.

Another possibility until now has been to use a wind-driven impeller or a turbine wheel, for example, as the second arming criterion, which is mounted in the fuze and senses the air flow after launch. For this purpose, the incident flow must strike the wind-driven impeller or turbine wheel via a channel which has an inlet and an outlet. This channel as well as the mounting for the wind-driven impeller or turbine wheel are sensitive to dirt and to icing, and are therefore unsuitable for use, for example, in sandy or dusty operating conditions and environments.

Accordingly, a need exists for providing a fuze for a projectile, in particular for a projectile that does not spin, having a second arming criterion without any continuous channel being provided for the safety and arming unit, and with automatic arming being possible by simple means.

So Summary of the Invention 0 0 7 / 0 8 3 0 J

According to the invention, there is provided a fuze for a projectile, in particular for a projectile that does not spin, the fuze having a first and a second arming criterion for its safety and arming unit, with the first arming criterion using the launch acceleration of the fuze, wherein the fuze has pressure and/or temperature sensors located at a distance from one another in order to measure a pressure and/or temperature difference, with the respective difference measured value being compared by means of a comparator with a predetermined threshold value, and with a corresponding comparison signal forming the second arming criterion for the safety and arming unit for the fuze of the projectile.

Pressure sensors and/or temperature sensors are preferably fitted at the fuze tip and on the fuze circumference, which are suitable for carrying out a pressure-difference measurement and/or a temperature-difference measurement when air flows past them during the flight phase of a projectile, and for unambiguously detecting the respective flight phase of the projectile, as a function of a predetermined threshold value. A corresponding comparison signal between the predetermined threshold value and the pressure and/or temperature difference measurement signal forms the second arming criterion for the fuze according to the invention.

This signal is therefore used as the second arming criterion, and leads to automatic arming of the fuze according to the invention.

Advantages achieved by the invention are that the safety for the user and the reliability are considerably improved, because the fuze is armed automatically, and because there are no openings into the interior of the fuze.

Detailed Description of the Invention

The invention will now be described by way of the following, non-limiting example with reference to the accompanying drawing.

Ce we2007/ 085049 _ In the drawing, Figure 1 shows an embodiment of a projectile fuze in accordance with the invention, which is illustrated schematically in a section view. The projectile is of the kind that does not spin.

The figure illustrates a fuze 10 for a projectile 12. The fuze 10 has a safety and arming unit 14 with a first and a second arming criterion. The first arming criterion uses the launch acceleration of the projectile 12. An acceleration sensor 16, which is operatively connected to the safety and arming unit 14, is used to detect the launch acceleration. This operative connection is indicated by the bent arrow 18.

The fuze 10 has sensors 20 at a distance from one another. One sensor 20 is provided at the fuze tip 22, and further sensors 20 are arranged at a distance from it, at equal intervals from one another along the circumference of the fuze 10. The sensors 20 are pressure sensors and/or temperature sensors. The pressure sensors 20 are suitable for measuring the pressure difference in accordance with Bernoulli's Law, and/or the temperature sensors are suitable for measuring the temperature difference when an incident airflow strikes the fuze 10, during the flight phase of the projectile, and for unambiguously detecting the flight phase of the projectile 12 as a function of a predetermined threshold value. For this purpose, the measurement signals produced by the sensors 20 are compared in a comparator 24 with the said threshold value. The threshold value is indicated by the arrow 26. The operative connection between the sensors 20 and the comparator 24 is represented by the bent arrow lines 28.

Once the flight phase of the projectile 12 has been unambiguously detected with the aid of the sensors 20, then the corresponding comparison signal forms the second arming criterion for the safety and arming unit 14 for the fuze 10. This comparison signal is indicated by the arrow 30.

£:2007/ 08509

List of Reference Symbols: 10 Fuze (for 12) 12 Projectile 14 Safety and arming unit (of 10) 16 Acceleration sensor (of 10 for 14) 18 Arrow/operative connection/first arming criterion (for 14) 20 Sensors (of 10) 22 Fuze tip (of 10) 24 Comparator (of 10 for 20) 26 Threshold value (for 24) 28 Arrow/operative connection (between 20 and 24) 30 Arrow/comparison signal/second arming criterion (for 14)

It is to be appreciated, that the invention is not limited to any particular embodiment or configuration as hereinbefore generally described or illustrated.

The claims which follow are to be considered an integral part of the present disclosure. Reference numbers (directed at the drawing) shown in the claims serve to facilitate the correlation of the integers of the claims with illustrated features of the preferred embodiment, but are not intended to restrict in any way the language of the claims to what is shown in the drawings, unless the contrary is clearly apparent from the context.

Claims

#E2007/ 08599 BE 1] 111 CL

1. A fuze for a projectile, in particular for a projectile that does not spin, having a first and a second arming criterion for its safety and arming unit (14), with the first arming criterion using the launch acceleration of the fuze (10), wherein the fuze (10) has pressure and/or temperature sensors (20) located at a distance from one another in order to measure a pressure and/or temperature difference, with the respective difference measured value being compared by means of a comparator (24) with a predetermined threshold value (26), and with a corresponding comparison signal (28) forming the second arming criterion for the safety and arming unit (14) for the fuze (10) of the projectile (12).

2. A fuze as claimed in claim 1, wherein at least one sensor (20) is provided at a tip (22) of the fuze (10), and a number of sensors (20) are provided axially at a distance from the fuze tip (22) along the circumference of the fuze (10).

3. A fuze as claimed in claim 2, wherein the sensors (20) are provided at uniform intervals along the circumference of the fuze (10).

4, A fuze for a projectile according to the invention, as hereinbefore generally described.

5. A fuze for a projectile as specifically described with reference to or as illustrated in the accompanying drawings.

BE2007/ 08508 So 6. A fuze for a projectile including any new and inventive integer or combination of integers, substantially as herein described.

DATED AT PRETORIA, THIS 5™ DAY OF OCTOBER 2007. HAHN & HAHN INC.

APPLICANT'S ATTORNEYS .