Ordnance – Fuse setters – Combined with projecting – launching or releasing devices
Reexamination Certificate
1999-01-13
2001-01-09
Jordan, Charles T. (Department: 3641)
Ordnance
Fuse setters
Combined with projecting, launching or releasing devices
C089S006000, C102S265000, C102S270000
Reexamination Certificate
active
06170377
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method and to an arrangement to make it possible, in single-shot and also semi-automatic and fully automatic shell-firing barrel weapons, and particularly in those which are provided with rifled barrels made of steel, to transmit, contactlessly and inductively, relevant programming data to a programmable fuse function included in the respective shell while the shell is still situated in the cartridge chamber of the weapon.
BACKGROUND OF THE INVENTION
As far as detonating shells are concerned, the main effect of which on the target is achieved through splinter, it has been known for a long time that the effect on the target depends directly upon how close to the target the detonation takes place, and also whether this takes place above the target, which clearly produces the best effect, or on ground impact beside the target. Even though efforts are, of course, made to achieve direct strikes on the target, such direct strikes are not particularly frequent in spite of modern fire-control and missile-trajectory calculating instruments.
One way of bringing about air bursts directly above: the target aimed at is based on providing the shells with a programmable time fuse function which can be programmed for detonation at the trajectory distance from the firing point at which it is calculated that the target is situated. When using shells of this type it is desirable to carry out this programming as late as possible before firing. This is particularly the case with shell-firing infantry weapons where, with mobile positions, it may be expected that both oneself and the target are continuously moving around on the battlefield. Under these circumstances, it would therefore be a clear advantage if the time fuse function of the shells could be programmed as late as possible before firing, e.g. when the shell is ready for firing in the cartridge chamber of the shell-firing weapon.
Arranging such programming of the time fuse function of the shells inside the cartridge chamber of the weapon, however, involves certain problems because the cartridge chamber constitutes part of the barrel. However, it is heretofore known, however, that it is possible to program in an inductive manner electronic shell fuses which are designed in a special manner.
Since all shell-firing weapons, except possibly those of one-shot type, have barrels made of steel which are both electrically conductive and magnetic, inductive fuse programming was previously only possible before loading of the weapon or alternatively while the shell was being fed from a magazine to the cartridge chamber of the weapon. Furthermore, EP-A1-0300255 and EP-A1-0467055 describe proposals for how the same type of inductive programming can be carried out immediately after the shell has left the barrel. In these arrangements, it is proposed that the coil which is to supply the programming signal be placed immediately outside the mouth of the barrel so that the shell passes through it. For various reasons, these solutions have proved to be more difficult to implement in practice than was originally theoretically assumed. Then, as far as programming further away from the firing point is concerned, along the actual missile trajectory, this involves such great technical complications that, although they are by no means insurmountable, they would probably only be justified in terms of effectiveness in larger calibers such as 10.5 cm and above.
SUMMARY OF THE INVENTION
As an alternative to the previously used variants indicated above, both a new method and a new arrangement are now proposed according to the present invention for inductive programming directly in the cartridge chamber of the programmable time fuses for the shells of shell-firing barrel weapons intended for both single-shot and also for semi-automatic and fully automatic firing.
The invention is based on the fact that the part of the material in the barrel of the weapon which constitutes the cartridge chamber of the weapon is replaced by a non-magnetic insert around which one or more coils for inductive programming of the time fuse of the shells are wound. However, the problems are not completely solved by this arrangement alone. This is because a further prerequisite for it to be possible for the inductive programming of the time fuses to function is that this non-magnetic insert is not electrically conductive either. If it were electrically conductive, it would form a short-circuited layer which would prevent the programming signal from being transmitted to the time fuse of the shell. It would be possible to satisfy both these conditions immediately if the insert could be made of a material which was not magnetic and had such poor electric conductivity that it was of the type usually referred to as electrically non-conductive material. Since it must also be taken into account that the material in the insert must withstand the high temperature and the high pressure which occur in the barrel on firing, the number of possible materials is very limited. One group of materials which are both non-magnetic and electrically non-conductive and are known to be hard, hard-wearing and heat-resistant, and therefore, would theoretically be suitable for producing cartridge chamber inserts of the type in question, are the so-called ceramic metals. As a rule, however, these materials are brittle. Thus it would be difficult today to produce entire cartridge chamber inserts of the type in question from such ceramic metals.
According to a preferred development of the invention, it is therefore proposed that the cartridge chamber inserts themselves are made of a non-magnetic metal with sufficiently high hardness and heat resistance such as e.g. niobium or stainless steel, a direct short-circuiting of the surrounding coils being prevented by providing the insert with a gap in the longitudinal direction of the barrel. Electric insulation of the gap can in this connection advantageously be constituted by a suitable ceramic metal.
If the insert is made of stainless steel for example, there is nothing to prevent the barrel rifling being continued into the insert. This presupposes, however, that the insert is fastened non-rotatably in the barrel.
The invention has been defined in its entirety in the following patent claims and at the same time will now be described in somewhat greater detail in conjunction with the attached figures.
The invention has here been illustrated in a variant conceived for use on a so-called shell sprayer. As this type of weapon is generally known and exists in a number of variants with mechanically similar operation, only components essential for the invention have been included in the figures, in which
REFERENCES:
patent: 4005631 (1977-02-01), Kaiser et al.
patent: 4644930 (1987-02-01), Mainhardt
patent: 4649796 (1987-03-01), Schmidt
patent: 4664013 (1987-05-01), Wegner et al.
patent: 4711152 (1987-12-01), Fortunko
patent: 4979424 (1990-12-01), Becker et al.
patent: 5117732 (1992-06-01), Munzel et al.
patent: 0 118 122 A1 (1984-09-01), None
patent: 0 300 255 B1 (1991-04-01), None
patent: 0 467 055 B1 (1993-10-01), None
Fohrman Erik
Hagstrom Bjorn
Jern Sven-Åke
Johansson Nils
Larsson Rolf
Bofors AB
Jordan Charles T.
Pollock, Vande Sande & Amernick, R. L.L.P.
Thomson Michelle
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