US3516358A - Fin stabilized projectile - Google Patents

Fin stabilized projectile Download PDF

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Publication number
US3516358A
US3516358A US710263A US71026368A US3516358A US 3516358 A US3516358 A US 3516358A US 710263 A US710263 A US 710263A US 71026368 A US71026368 A US 71026368A US 3516358 A US3516358 A US 3516358A
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US
United States
Prior art keywords
projectile
barrel
annular grooves
grooves
gases
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US710263A
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English (en)
Inventor
Paavo Manninen
Niilo Asikainen
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Tampella Oy AB
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Tampella Oy AB
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Filing date
Publication date
Application filed by Tampella Oy AB filed Critical Tampella Oy AB
Application granted granted Critical
Publication of US3516358A publication Critical patent/US3516358A/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B30/00—Projectiles or missiles, not otherwise provided for, characterised by the ammunition class or type, e.g. by the launching apparatus or weapon used
    • F42B30/08—Ordnance projectiles or missiles, e.g. shells
    • F42B30/10—Mortar projectiles

Definitions

  • Fin stabilized projectiles of the type of this invention generally have an elliptical shaped body in longitudinal cross section and a tail unit rim comprising radial fins. Shallow circumferential grooves are generally provided in the region of the largest diameter of the projectile body. The number of grooves is usually limited to a small number. The maximum diameter of such a projectile is usually slightly less than the inner diameter of the barrel from which the projectile is to be fired.
  • the barrel is more or less inclined.
  • the inclined nature of the barrel causes an uneven air gap to result between the surface of the projectile and the barrel at the location of the maximum diameter of the projectile. That is, the projectile rests on the lower part of the inner wall of the barrel thereby resulting in a slight increase in the air gap at the upper part of the inner wall.
  • gases stream into this air gap and reduce the pressure at this point. The gases at the lower part of the inner wall are partly trapped below the projectile. When the reduction of pressure takes place in the air gap above the projectile the trapped gases below the projectile are subjected to an increase of pressure.
  • the tail unit guides the projectile through the smooth inner barrel upon firing.
  • the uneven distribution of gas pressure within the barrel as described above causes the projectile to be knocked to and fro as a function of the position of the center of gravity of the projectile with respect to its maximum diameter.
  • the tail unit When the tail unit is a short one, it will be the first part to knock against the upper part of the inner wall.
  • the region of the maximum diameter of the projectile When the tail unit is very long, the region of the maximum diameter of the projectile will be the first part to knock against the upper part of the inner wall.
  • the projectile generally knocks three times against the inner wall when passing through the smooth inner barrel. This knocking movement takes place both in a vertical direction and in a cross sectional direction.
  • Such a knocking movement of the projectile as it passes through the barrel will clearly adversely affect the trajectory of the projectile.
  • the banking of the projectile as it leaves the barrel results in a slight deviation from the theoretical trajectory.
  • This banking caused by the knocking movement will clearly afiect the trajectory in either a vertical or lateral direction or as a result of a combination in both directions.
  • the problem of such a knocking movement can clearly result in a movement of the gun. Therefore in such a case, a flying projectile is subject to both interior and exterior ballistic influences.
  • Such an adverse knocking movement also affects the type material used in the construction of the tail unit. This material must be relatively strong so that it can withstand the knocking action without being undesirably deformed.
  • Such an undercut pocket produces an eddy motion of the gases thereby substantially preventing an initial rapid passage of the following gases to the front of the barrel along the upper surface of the projectile.
  • Such an eddy motion reduces the local velocity of the gases along the upper surface of the projectile in the gap between the projectile and the barrel. The reduced velocity results in an increased pressure of the gas surrounding the projectile. Therefore, the gases surrounding the lower half of the projectile have a higher pressure than those in the space or gap of the upper half of the projectile and barrel combination. The balancing of the pressure within the barrel in this manner causes the projectile to be held suspended near the theoretical axis position of the barrel from which it is being fired.
  • Another object is to provide the projectile having grooves which are undercut in the direction of the nose located at the maximum diameter of the projectile body. This achieves a more settled passage of the projectile through the smooth barrel and thereby improves both ballistic properties and range of the projectile.
  • the undercut annular groove includes a front surface sloping inward at a pointed angle, a reversing arc surface which is located substantially inside the undercut and adjoining concave arc portion.
  • the undercut is in the direction toward the nose of the body of the projectile. This undercut construction effectively traps the gases streaming through the gap between the projectile and the barrel. In this manner, the flow velocity around the projectile is substantially stabilized and a smooth passage of the projectile through the barrel results.
  • annular grooves located at regular intervals on the projectile than were used heretofore.
  • the annular grooves should extend from the region of the maximum diameter towards the tail of the projectile. With this arrangement, the gases within the barrrel are affected before reaching the region of the maximum diameter of the projectile.
  • the annular grooves may extend to approximately the last half of the rear part of the projectile.
  • the annular grooves may also have dilferent depths along the length of the projectile.
  • the annular grooves in front of the region of the maximum diameter are constructed to be flatter than those located in the region behind the maximum diameter of the projectile.
  • FIG. 1 is a longitudinal view of a fin stabilized projectile constructed in accordance with the invention shown partly in section.
  • FIG. 2 is an enlarged sectional view of annular grooves as they are arranged on the projectile in accordance with this invention.
  • FIG. 3 is an enlarged view of the section I indicated on FIG. 1 of the drawings. This section I is shown in relation to the inner wall of the barrel from which the projectile is to be fired.
  • the fin stabilized projectile generally designated 1 comprises a body 2 which carries an igniting device 3 on its front end.
  • a tail unit 5 includes fins 6 and a tail unit tube 4 which is screwed on the body 2 at the rear end.
  • An explosive charge 7 is shown inside the body 2 of the projectile 1.
  • a ground cartridge and an ignition cartridge, neither of which are shown, are located inside the tail unit tube 4.
  • a number of annular grooves 8 are located on the body 2 of the projectile 1 in the region of the largest body diameter.
  • each annular groove 8 is undercut in a direction toward the nose of the projectile.
  • Each annular groove 8 comprises a front surface 9 sloping inwardly at a pointed angle with the outer surface of the body 2, a concave arc portion 10 and a reversing arc portion 11 which connects the front surface 9 to the concave arc portion 10.
  • This reversing arc portion 11 is located substantially inside the space of the annular groove 8 formed by the undercut front surface 9.
  • the distance between the barrel wall 12 and the projectile 2 at its maximum diameter may be relatively large.
  • the special construction of the annular grooves 8 substantially prevents the knocking action of the projectile 2 inside the barrel wall 12.
  • the gases are substantially prevented from passing more easily along the upper surface of the projectile 2 even though a larger gap exists between the projectile and the barrel wall 12 at that point thanlori the lower surface of the projectile 1 as it is inclined against the barrel wall 12 before firing.
  • An elfective number of undercut annular grooves 8 is provided at regular intervals to obtain the desired results.
  • the region 13 including the annular grooves 8 may extend from the maximum diameter of the body 2 of the projectile 1 to a point located relatively far towards the tail unit 5.
  • the specific embodiment has fourteen (14) annular grooves provided relatively close to each other at regular intervals along the surface of the body 2.
  • the groove region 13 extends to approximately one-half of the rear portion of the projectile body 2. This achieves a massive effect on the gases which are inclined to pass through the gap between the projectile 1 and the barrel wall 12.
  • a larger portion of the annular grooves 8 should be situated on the projectile body 2 towards the tail unit 5 behind the location of the maximum diameter of the body 2.
  • the annular grooves 8 are cut deeper than those grooves provided heretofore on similar projectiles.
  • depth of the annular grooves 8 may be three to four times the size of the gap between the body 2 and the barrel wall 12.
  • the annular grooves 8 may have different depths.
  • the width of the groove opening may be one point eight to two times the depth.
  • the non-recessed distance 14 located between the annular grooves 8 may be approximately equal to the depth of the grooves.
  • a non-gyrating fin stabilized projectile comprising (a) an elliptical shaped body having a maximum diameter, a nose and a rear portion,
  • said grooves being undercut and having a front surface sloping inwardly at a pointed angle with respect to the surface of said body and in a direction toward the nose of the body,
  • the said region of the annular grooves extends from the maximum diameter of the projectile body in a direction toward the rear portion.
  • the said region ofthe annular grooves extends from the maximum diameter of the projectile body in a direction toward the rear portion.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Toys (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
US710263A 1967-03-08 1968-03-04 Fin stabilized projectile Expired - Lifetime US3516358A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEO0012353 1967-03-08

Publications (1)

Publication Number Publication Date
US3516358A true US3516358A (en) 1970-06-23

Family

ID=7352739

Family Applications (1)

Application Number Title Priority Date Filing Date
US710263A Expired - Lifetime US3516358A (en) 1967-03-08 1968-03-04 Fin stabilized projectile

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Country Link
US (1) US3516358A (enrdf_load_html_response)
DE (1) DE1578192C3 (enrdf_load_html_response)
DK (1) DK130729B (enrdf_load_html_response)
FI (1) FI43695B (enrdf_load_html_response)
FR (1) FR1556672A (enrdf_load_html_response)
GB (1) GB1179517A (enrdf_load_html_response)
IL (1) IL29520A (enrdf_load_html_response)
NL (1) NL156814B (enrdf_load_html_response)
NO (1) NO120173B (enrdf_load_html_response)
SE (1) SE336286B (enrdf_load_html_response)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4651454A (en) * 1985-05-06 1987-03-24 Harris Paul C Spear gun having gas sealing means
US4742775A (en) * 1985-05-06 1988-05-10 Harris Paul C Power load for underwater spear gun
US5514023A (en) * 1994-02-23 1996-05-07 Warner; Jon A. Hand launchable hydrodynamic recreational device
US6699091B1 (en) 1999-11-04 2004-03-02 Jon A. Warner Hand-launchable underwater projectile toy
US20050250409A1 (en) * 2004-05-04 2005-11-10 David Silverglate Toy submersible projectile
US20070123139A1 (en) * 2005-05-18 2007-05-31 Warner Jon A Self-propelled hydrodynamic underwater toy

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH703467A1 (de) * 2010-07-23 2012-01-31 Alexander Ernst Quetschkalibergeschoss für konische Läufe.

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1628527A (en) * 1925-01-12 1927-05-10 Brandt Edgar William Projectile for smooth-bore guns
GB309863A (en) * 1928-04-16 1930-05-08 Vaclav Holek Improvements in or relating to projectiles

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1628527A (en) * 1925-01-12 1927-05-10 Brandt Edgar William Projectile for smooth-bore guns
GB309863A (en) * 1928-04-16 1930-05-08 Vaclav Holek Improvements in or relating to projectiles

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4651454A (en) * 1985-05-06 1987-03-24 Harris Paul C Spear gun having gas sealing means
US4742775A (en) * 1985-05-06 1988-05-10 Harris Paul C Power load for underwater spear gun
US5514023A (en) * 1994-02-23 1996-05-07 Warner; Jon A. Hand launchable hydrodynamic recreational device
US6699091B1 (en) 1999-11-04 2004-03-02 Jon A. Warner Hand-launchable underwater projectile toy
US20040259463A1 (en) * 1999-11-04 2004-12-23 Warner Jon A. Hand-launchable underwater projectile toy
US20050250409A1 (en) * 2004-05-04 2005-11-10 David Silverglate Toy submersible projectile
US7052357B2 (en) 2004-05-04 2006-05-30 Big Time Toys, Llc Toy submersible projectile
US20070123139A1 (en) * 2005-05-18 2007-05-31 Warner Jon A Self-propelled hydrodynamic underwater toy
US8033890B2 (en) 2005-05-18 2011-10-11 Warner Jon A Self-propelled hydrodynamic underwater toy

Also Published As

Publication number Publication date
DK130729C (enrdf_load_html_response) 1975-09-01
FR1556672A (enrdf_load_html_response) 1969-02-07
DE1578192C3 (de) 1974-07-04
FI43695B (enrdf_load_html_response) 1971-02-01
SE336286B (enrdf_load_html_response) 1971-06-28
NL6803296A (enrdf_load_html_response) 1968-09-09
DE1578192A1 (de) 1970-07-23
NL156814B (nl) 1978-05-16
DK130729B (da) 1975-04-01
DE1578192B2 (de) 1973-11-29
GB1179517A (en) 1970-01-28
IL29520A (en) 1972-01-27
NO120173B (enrdf_load_html_response) 1970-09-07

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