Patent Application
20100300321
The present invention relates to a shell intended for firing from a weapon, preferably a mortar weapon, the shell being designed for locking in a mortar to prevent movement of the shell when adjusting the angle of elevation of the mortar prior to firing. The invention also relates to a mortar weapon designed for firing said type of shell and a system comprising said shell and mortar.
Conventional mortar weapons (also referred to as mortars) and mortar ammunition has looked pretty much the same since the days of the First World War.
Conventional mortars are not especially suited to mounting on vehicles. Where installed on vehicles extensive manual handling is required, both of the mortar by redeploying vehicles and of the shell by changing the number of charges. It is necessary either to sacrifice armour protection and to load the mortar manually from open hatches, or to design complicated loading apparatus which moves shells from the inside of the vehicle to the muzzle of the mortar barrel. A further problem is that the shell lies loosely in the barrel, which means that the mortar can only be fired with a high angle of elevation. If attempts are made to tip the mortar, that is to say to lower the barrel below a certain angle of elevation, there is a great risk that the shell will shift or slide out of the barrel.
Devices to prevent the shell shifting prior to firing, for example when adjusting the angle of elevation of the barrel, have long been known. GB 2 260 390 A discloses and describes a device for locking a shell.
The locking device consists of a locking plate and snap fastening. The locking device is fixed to the rear part of the shell, behind the fins of the shell, following which the shell is rammed home into the weapon. The locking plate is disc-shaped and has an outside diameter greater than the inside diameter of the barrel. When ramming the shell home in the barrel the locking plate will be rammed home against a shoulder, which is formed due to the fact that the breech opening diameter of the barrel has been made greater than the remaining diameter of the barrel. The shell is thereby fixed in a specific position inside the barrel. In firing, the locking element is torn off the shell and remains in the barrel. Before the mortar can be reloaded the locking element must be taken care of, either manually or with the aid of a special tool. Locking elements therefore entail a further component that has to be handled as part of the weapon logistics system.
The component must be transported, handled by the ammunition handling system, fitted to the shell, removed from the barrel before the next round can be rammed home, sorted out as scrap and assigned for destruction or reuse. Due to the high pressure and temperature that occur in firing, there is often a risk of the locking element being burned onto or otherwise adhering to the to the breech opening, which in the worst case can lead to fracture of the barrel. In order to cope with the burnt-on component or residues of components, special tools are required, which represent extra equipment in the weapons system. Handling the locking element therefore entails a slower and more complicated weapons system, in which the risk of barrel fracture is great owing to the locking element.
A first object of the present invention is to provide a shell, which is intended for locking in a mortar to prevent movements of the shell when adjusting the angle of elevation of the barrel prior to firing, without the need to arrange any additional locking components on the shell.
A second object of the invention is to provide a mortar which is designed for securing said shell without the need to arrange any additional securing components in the mortar.
A third object of the invention is to provide a shell which is designed for locking in a mortar, which shell will not give rise to any loose parts in the mortar when firing
A fourth object of the invention is to provide a shell for locking, which is simple and inexpensive, and which does not adversely affect the performance of the shell.
A fifth object of the invention is to provide a system for firing a shell, the system comprising said shell and mortar.
Said objects and other objects not enumerated here are satisfactorily achieved within the scope of the present independent patent claims. Embodiments of the invention are specified in the dependent patent claims.
The invention has therefore provided a shell designed for locking in a mortar in order to prevent movements of the shell prior to firing, without the need to arrange any additional components on the shell.
According to the invention a mortar has also been provided, which is designed for securing said shell without the need to arrange any additional components in the mortar.
According to the invention a shell has furthermore been provided for locking in the mortar, the shell preventing loose parts remaining in the barrel after firing and the shell being simple and inexpensive, and not adversely affecting the performance of the shell.
Finally, according to the invention a system for firing a shell has been provided, the system comprising said shell and mortar.
The essential characteristic of the shell according to the invention is that the shell comprises a locking part, the locking part forming an integral part of the shell and the locking part being designed so that the shell, after ramming home in the mortar, is locked to a corresponding securing device arranged in the mortar.
According to further aspects of the shell according to the invention:
The essential characteristic of the mortar according to the invention is that the mortar comprises a securing device for securing the shell and a breech closure comprising a contact base, and that the contact base comprises a securing part comprising at least two securing heels for securing the shell.
According to further aspects of the mortar according to the invention:
The essential characteristic of the system according to the invention for firing a shell according to the invention is that the system comprises said shell and said mortar.
The invention proposed above affords several advantages. No additional components are needed for locking a shell in a specific position in a mortar. The locking part constitutes an integral part of the shell. The logistics system of the weapon is simplified, fewer components need to be handled and transported. The ammunition handling system becomes simpler, faster and less expensive. The shell handling when ramming home is simplified, no additional components need to be fitted to the shell or disposed of after firing. The risk of barrel fracture due to loose parts being burnt on inside the barrel is eliminated.
According to the invention the locking part may also afford advantages with regard to the performance of the shell, in that the deformable part of the locking part, the tubular flange, the end flange or the locking heels are deformed and straightened out directly rearwards. Straightening out directly rearwards is reckoned to have a beneficial effect on the stabilization characteristics of the shell, since the part directed rearwards functions as an additional fin.
Further advantages and effects will emerge from a study and consideration of the following detailed description of the invention, including a number of advantageous embodiments thereof, and the figures of the drawings attached. The method and the device according to the invention have been defined in the following patent claims.
The invention will be described in more detail below with reference to the drawings attached, in which:
The mortar 6 in
As can be seen from
Since the shell 1 does not have any charge casing, the contact base 18 of the breech closure 10 is provided with a rubber obturator of the same type as used in screw breech mechanism weapons, not shown. As can be seen from
The shell 1 is rammed into the barrel 7 in that the breech closure holder 16 for the breech closure 10 is advanced by means of the operating screw to a predefined position in the breech opening of the barrel 7. Throughout the ramming process until the shell is rammed in the barrel 7, the shell 1 is secured against the contact base 18 in the breech closure 10. In as much as the contact base 18 does not move in the barrel 7 after ramming home of the shell 1, it can be used for securing the shell 1. The shell 1 is secured by means of a securing part 19, which is arranged on the contact base 18, the securing part 19 forming an integral part of the contact base 18.
When ramming home the shell 1, the shell 1 is locked in a specific position in the barrel 7 in that the periphery of the securing part 19 is locked against a shoulder 23 in the breech opening of the barrel, the shoulder 23 having been formed in that the breech opening diameter of the barrel 7 has been made larger than the remaining inside diameter of the barrel 7.
The securing part 19 in
The flange 4 in
Because the shell 1 is firmly secured throughout the loading process, it can be rammed home at high speed without the risk of it continuing into the barrel 7 and losing contact with the contact rod 18 and the contact device for electrical firing. A high ramming speed means time-saving and a high rate of fire. In the event of a possible misfire, the shell 1 can easily be drawn out of the barrel 7 by means of the breech closure 10. The mortar 6 is cable of firing at all angles of elevation, even tipping angles. There is no need to rely on the force of gravity to hold the shell 1 in the correct position. Low angles of elevation can be used when the mortar 6 is to be used for directed fire. Conventional mortars are limited to angles of elevation of 45-85 degrees, due to the fact that the shell 1 lies loosely in the barrel.
a and 5b show an alternative embodiment of a shell 26 according to the invention. The shell 26 is designed with an annular fin section, the annular fin section comprising fixedly mounted fins 29 enclosed by a tubular or cylindrical section 27, the rear part of the tubular or cylindrical section 27 being embodied as a tubular flange 28, also referred to as a tube flange 28, the tube flange 28 comprising a flange part projecting radially outside the shell 26, see
The shell 26 is introduced into the breech opening of the barrel 7 in the firing direction A of the shell by means of the contact base 18, the radially projecting part of the tube flange 28 being pressed against the shoulder 23. In the same way as the end flange 4 in
When the shell 26 is fired, the tube flange 28 is bent backwards and forms a part of the fin assembly, which allows the shell 26 free passage through the barrel 7, and since the tube flange 28 straightens out it does not present any additional air resistance during the trajectory phase of the shell 26. It is also possible to design the tube flange 28 so that after straightening out the tube flange 28 exerts a stabilizing effect on the flight characteristics of the shell 26.
a and 7b further show an embodiment of a shell 35 according to the invention. The shell 35 comprises fixed stabilizer fins 36, the fixed stabilizer fins 36 comprising deformable parts, said locking heels 37, the locking heels 37 being arranged on rear vane tips of the stabilizer fins 36. The locking heels 37 are an integral part of the stabilizer fins 36 and comprise a part protruding radially in relation to the longitudinal axis B-B of the shell 35. The locking heels 37 constitute locking parts of the shell 35 and lock the shell 35 in that the radially protruding part of the locking heels 37 is rammed against the shoulder 23 when the contact rod 18 presses the shell 35 into the breech opening of the barrel 7. In the same way as the end flange 4 and the tube flange 28, the locking heels 37 are of deformable design, either in that that they are composed of a deformable material and/or that they have been made thicker or thinner and/or in that they comprise a mechanically weakened section.
The shell is therefore locked in a specific position in the breech opening of the barrel in that a flange or locking heel is pressed against a shoulder in the breech of the barrel and in that the shell is secured against the contact base, which introduces the shell into the barrel. This means that the shell cannot move either forwards or backwards after ramming home. The mortar can be aimed with any angle of elevation, even tipping angles, without the shell shifting. A conventional muzzle-loaded mortar requires angles of elevation of at least approximately 45 degrees in order that the shell will bear against the contact base. The mortar according to the invention affords optimum performance, that is to say the best possible securing of the shell in the barrel and scope for automatic ammunition handling if shells with annular fins are used. Conventional mortar ammunition of standard type may also be used in this type of mortar weapon, however. The sphere of application, however, is limited to high angles of elevation, in which the shell rests against the contact base under its own weight.
The invention is not limited to the examples shown but may be modified in various ways without departing from the scope of the patent claims. The embodiment of the locking part of the shell and the securing part of the mortar can therefore be modified within the bounds of feasibility, provided that no additional components are added or fitted to the shell and/or in the mortar and that no loose or burnt-on parts remain in the barrel of the mortar after firing.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0702645.3 | Nov 2007 | SE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/SE08/00612 | 10/29/2008 | WO | 00 | 5/27/2010 |
