Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B10/00—Means for influencing, e.g. improving, the aerodynamic properties of projectiles or missiles; Arrangements on projectiles or missiles for stabilising, steering, range-reducing, range-increasing or fall-retarding
  • F42B10/02—Stabilising arrangements
  • F42B10/04—Stabilising arrangements using fixed fins
  • F42B10/06—Tail fins

Definitions

• the invention is mortar projectile furnished with slanted and bent stabiliser wings that enable the projectile to rotate around its longitudinal axis, this enhancing its stability and precision as well as range and efficiency at the target.
• F 42 B 10/00 Weapons - Ammunition and Blasting - Means for influencing, e.g. improving, the aerodynamic properties of projectiles or missiles; Arrangements on projectiles or missiles for stabilising, steering, range-reducing, range-increasing or fall-retarding.
• the technical problem that is solved by this invention relates to mortar projectiles with stabilisers, where fins' diameter is fixed and equal to the mortar barrel bore (calibre fins), but where fins are designed and fitted on the stabiliser, related to the projectile axis, to enable rotation of the axis during flight, this enhancing the projectile stability, precision and range.
• stabilisers are based on classic solutions of flat fins. Such solutions are satisfactory with projectiles of low range and precision demands. Such projectiles are affected by weather. When larger ranges are demanded, such projectiles are unstable, this resulting in non-precision (large scattering of hits).
• Stabilisers with calibre fins has its outer diameter fixed and equal to the mortar barrel bore.
• Number of fins may be 6 or 8. Such projectiles do not rotate during flight, are unstable and have large scattering of hits.
• Stabilisers with have fins that unfold when the projectile leaves the barrel, after which the projectile has outer diameter larger than the mortar barrel bore.
• Over-calibre fins fully solve the problem of flight stability and achieve fine results with regard to hit scattering and range.
• the essence of the invention is mortar projectile, to be fired from smooth bore mortars, furnished with fins of fixed outer diameter that is equal to the barrel bore
• All fins are of similar shape, area and dimensions. Related to the projectile calibre, they are made to produce minimum resistance in the flight. The fin bases and peaks are designed to approach the shape of a water drop.
• the increased-range mortar projectile comprises point-detonating fuse with safety pin; shell with the basic charge and ring for lessening the powder gas losses; stabiliser with slanted and bent fins; additional charge with additional charge carrier; and propelling charge with detonating cap 5.
• Figure 1 shows the complete increased-range mortar projectile, with a partial cross-section, side view.
• Figure 2. shows the mortar projectile from Fig. 1 , with no additional charge (partial cross-section) - side view.
• Figure 3. shows stabiliser of the increased-range mortar projectile - side view.
• Figure 4. shows stabiliser of the increased-range mortar projectile - front view.
• Figure 5. shows the stabiliser fin position relative to the stabiliser and projectile axes, base cross-section - top view.
• Figure 6. shows stabiliser fin, base cross-section - top view.
• Figure 7. shows stabiliser fin, top cross-section - top view.
• Figure 8. shows stabiliser fin - top view.
• Figures 1 , 2 and 3 show that the increased-range mortar projectile, to be fired from smooth bore barrel, consists of the following assemblies:
• Assembly A projectile head, including the fuse 1 with safety pin 2, which, upon hitting the target causes explosion of the basic charge;
• Assembly B projectile body, including the shell 3 which houses the basic charge 4 and the ring 5 which seals between the projectile and the barrel to lessen powder gas losses from the lower part of the barrel at the moment of firing the projectile;
• Assembly C stabiliser, including the stabiliser body 6, on the outer side of which there are fins 9, and through the body there are openings 7 to let the basic-charge powder gas out, and thread 8 to connect the stabiliser and the projectile body 3;
• Assembly D propelling charge, including the propelling charge 17 and the detonating cap 18;
• Assembly E additional charge, including the vessels 19 with powder charge 20 and carrier 21 which keeps the vessels 19 in a given position.
• the increased-range mortar projectile to be fired from smooth bore barrels, and rotating around its longitudinal axis during the flight, may have stabilisers of various numbers of slanted and bent fins.
• Figs. 1 and 2 show the increased-range mortar projectile furnished with the stabiliser C with eight regularly distributed fins. At projectiles with eight fins 9, fins are fitted on the stabiliser body 6 symmetrically relevant to the projectile axis, turned by 45° one from another, Fig. 4.
• All fins are identical by shape, area and dimensions and, as related to the projectile calibre, they are designed to produce minimum resistance during the projectile flight.
• Figs. 5 and 6 show cross-section of the base of a fin 9
• Fig. 7 show the top of a fin
• Fig. 8 top view of a fin.
• the side 10 of the fin 9 is straight, whereas the side 11 is designed as a curve of two lines: line 12 and line
• the line 12 is parallel to the edge 10.
• the front part of the edge 11 follows the line 12.
• the rear crossing of the side 10 and the bent part of the side 11 is constructed of the minimum, technologically required, thickness - ideal would be the shape of a dull knife 15.
• the front part of the fin 16, from base to top, is designed like a half of ellipse.
• Fin base cross-section, Fig. 6, and top cross-sections, Fig. 7, are designed so that their aerodynamic shape approaches the shape of a water drop, Fig. 8.
• fins 9 change their thickness from the centre towards the ends, by technological angles designed to make its extracting from the tool easier.
• Fins 9, viewed from a side, Fig. 3, are designed to enable extraction from the tool and to achieve the most favourable aerodynamic shape.
• Each fin 9 is fitted on the stabiliser body 6 slanted by its front edge by the angle ⁇ , which is larger than zero, relative to the projectile axis. Therefore, air flow over the fins during the flight creates on the slanted fin surface a force that makes the projectile to rotate around its longitudinal axis.
• the described fin geometric shape and projectile rotation during the flight increase the projectile stability which, again, results in the projectile increased range with lesser scattering of hits and larger shooting precision.
• Centre of gravity of the projectile is determined by distribution of masses within the projectile.
• the increased-range mortar projectile to be fired from smooth bore barrels, with stabiliser that enables rotation of the projectile during the flight, embodied in the above described way, results in enhanced projectile stability and range, larger precision and lesser scattering of hits, which has a positive effect to the projectile technology and cost.

Landscapes

• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
• Stereo-Broadcasting Methods (AREA)
• Carbon Steel Or Casting Steel Manufacturing (AREA)
• Portable Nailing Machines And Staplers (AREA)

Applications Claiming Priority (1)

Publications (2)

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• 2002
  • 2002-08-06 AT AT02765127T patent/ATE391280T1/de not_active IP Right Cessation
  • 2002-08-06 WO PCT/HR2002/000036 patent/WO2003029747A1/fr not_active Ceased
  • 2002-08-06 EP EP02765127A patent/EP1563247B1/fr not_active Expired - Lifetime
  • 2002-08-06 DE DE60225949T patent/DE60225949D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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