US3460478A - Projectile with sintered metal driving band - Google Patents

Projectile with sintered metal driving band Download PDF

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Publication number
US3460478A
US3460478A US725244*A US3460478DA US3460478A US 3460478 A US3460478 A US 3460478A US 3460478D A US3460478D A US 3460478DA US 3460478 A US3460478 A US 3460478A
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US
United States
Prior art keywords
projectile
driving band
annular groove
jacket
sintered metal
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
US725244*A
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English (en)
Inventor
Gottfried Ormanns
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rheinmetall Industrie AG
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Rheinmetall GmbH
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Filing date
Publication date
Application filed by Rheinmetall GmbH filed Critical Rheinmetall GmbH
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Publication of US3460478A publication Critical patent/US3460478A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B14/00—Projectiles or missiles characterised by arrangements for guiding or sealing them inside barrels, or for lubricating or cleaning barrels
    • F42B14/02—Driving bands; Rotating bands

Definitions

  • PROJECTI LE WITH SINTERED METAL DRIVING BAND Fil ed'Feb 'e, 1968' 2 Sheets-Sheet 1 G. ORMANNS V PROJECTILE. WITH SLNTERED METAL DRIVING BAND Filed Feb. 6, 1968 Aug. 12,1969
  • such bands In order to permit ready deformation of the driving band and thereby reduce the energy lost during engagement of the projectile with the rifling lands and grooves within a rifle barrel, while assuring that the other objectives for the driving band are met, such bands have long been made of solid bodies of ductile nonferrous metals such as copper, brass, or bronze.
  • driving bands were initially placed at the extreme rearward portion of a projectile casing or body in order to facilitate assembly of the projectile by having the driving hand held in position by a threaded ring or in order to permit forming the projectile casing with a weakened rearward portion.
  • the latter consideration was held to be particularly important in armor-piercing shells, where the driving band projecting outwardy beyond the principal diameter of the projectile casing caused difficulty in penetration of the projectile through armor plate.
  • Sintered metallic driving bands by way of constant with ductile meala bands, have a skeletal or porous structure, which permits the band to collapse or give away at the rifling lands, regardless of the velocity with which the projectile is fired. For this reason, pressures exerted on the barrel by the projectile are lower and improvements are realized in barrel life, obturation, range and accuracy for the given round of ammunition.
  • Sintered metal bands are, however, subject to certain deficiencies which did not appear in the earlier used ductile metal bands, resulting primarily from the very skeletal or porous structure of such sintered metals which provides the advantages leading to adoption of such driving bands. More particularly, while sintered metal structures will absorb compressive forces, as by collapse of the porous metal structure, such structures are somewhat friable and tend to crumble or fracture upon the exertion of tension froces on the metal body. Due to thislcharacteristic of sintered metal bodies, difliculties have been encountered in the a plication of driving bands made of sintered metal to projectiles intended to be fired at relatively high velocities.
  • tension forces on such bands arise largely as a result of couple forces or bending moments required in order to accommodate the resultant of the basic forces acting upon the driving band upon firing of the projectile.
  • the principal forces believed to give rise to tension on the driving band, and thus believed to be responsible for crumbling and fracture of sintered metal driving bands, are the force acting longitudinally of the projectile and resulting from relative movement between the projectile and the barrel and the radially directed force resulting from rotation about longitudinal axis of the projectile.
  • a projectile including a sintered metal driving band disposed in an external annular groove in the jacket of the projectile wherein the formation of the external annular groove is such that the exertion of tension forces on the drive band upon firing of the projectile through a barrel is substantially avoided, and the driving band is thereby protected against fracture and crumbling due to the forces imposed thereon being restricted to compressive force alone.
  • the annular groove and driving band are so positioned relative to the jacket of the projectile as to facilitate obtaining satisfactory ballistic performance for the projectile.
  • FIGURE 1 is a view of a portion of a projectile in accordance with the present invention in longitudinal sections showing the position of the external annular groove in the projectile jacket and the driving band as disposed in that groove;
  • FIGURE 2 is an elevation view, in section, of a driving band in accordance with the present invention prior to insertion thereof into the external annular groove in a projectile jacket;
  • FIGURE 3 is a diagram of the two aforementioned forces acting on a driving band during firing of a projectile.
  • FIGURE 4 is an enlarged elevation view, in section, of the driving band and projectile jacket.
  • FIGURE 1 illustrates a projectile jacket having a thin Wall portion 1, enclosing a central cavity 12 which may receive a hardened core or a charge of explosive, and a thick wall portion 11 spaced rearwardly of the thin wall portion of the jacket.
  • the driving band 3 is a body of sintered metal such as iron, which may have lubricant forced into the pores thereof to aid in reducing friction as the projectile is fired through a rifled barrel.
  • the annular groove 2 is cut into the jacket of the projectile in a particular manner such that the 'base wall 4 of the groove forms part of the generated surface of a cone whose apex is directed toward the rearward end or base of the projectile.
  • the cone whose generated surface includes the base wall 4 of the annular groove 2 has an apex located along a line including the longitudinal axis 15 of the projectile and at a predetermined particular apex angle such that the generated surface is at an acute angle to the longitudinal axis of the projectile.
  • the conic surface and the base wall 4 of the annular groove 2 extend in the direction of the resultant of deforming forces acting on the driving head band 3.
  • These forces are vectorially represented in FIGURE 3, and include the aforementioned axial force a and radial force 1'.
  • the resultant of these two forces, acting to deform the driving band 3, is represented vectorially as the resultant R.
  • the base wall 4 of the external annular groove 2 as part of the generated surface of a cone having an apex angle the same as the angle of the resultant R, the exertion on the driving band of a tension force included in a couple caused by the radial force 1' is avoided, and the forces acting on the driving band 3 upon firing of the projectile are restricted to compressive force only, directed toward the lower side wall 5.
  • the lateral contact surfaces or sidewalls 5 and 6 of the annular groove preferably are formed as undercuts, as has generally been done heretofore.
  • the inclination of the base wall 4 as part of the generated surface of a cone as described above permits forming the lower sidewall 5 as an enlarged supporting area for the driving band 3, so as to spread the compressive force applied to the driving band 3 by the resultant R, over as large an area as practical.
  • the radial width of the lower sidewall 5 preferably is from two-fifths to one-half the radial height of the driving band 3.
  • the external annular groove 2 is positioned relative to the thin wall portion 1 of the projectile jacket in a predetermined manner, facilitated by in inclination of the base wall 4. More particularly, the external annular groove 2 is positioned with the forwardmost portion of the groove spaced at a distance from the internal cavity 12 within the thin wall portion 1 substantially the same as the thickness of the thin wall portion of the jacket.
  • the relationship is more graphically illustrated by the dimensions identified as the thickness w of the thin wall portion and the wall thickness g at the thinnest point between the cavity 12 and the external annular groove 2 (FIGURE 1). Where these dimension are substantially equal, in accordance with the present invention, a substantially uniform strength for the projectile jacket is obtained.
  • the inclination of the base wall 4 permits obtaining this substantial equality of the dimensions g and w while the displacement of the forwardmost portion of the external annular groove 2 rearwardly of the cavity 12 within the thin wall portion (identified by the reference character h in FIGURE 1) is less than two-thirds the thickness w of the thin wall portion of the jacket.
  • a relatively far forward placement of the driving band 3 is obtained, with a coordinate reduction in precession of the projectile as compared with placement of the driving band at the extreme rear end of the jacket.
  • the base wall 4 of the external annular groove 2 is provided with a circumferentially spaced apart series of depressions and projections 7, directed in the longitudinal direction only of the projectile.
  • the fact that the projections and depressions 7 extend in the longitudinally direction only of the projectile permits compression of the sintered metal of the driving band 3 under the force of the resultant R as described above, without giving rise to tension forces on the sintered metal body.
  • the driving band 3 to be pressed into the annular groove 2 is formed with a generally trapezoidal cross-sectional configuration, with the base surface 8 of the driving band also forming a portion of a generated surface of a cone.
  • the width b of the driving band which decreases toward the outer diameter of the ring, is dimensioned to be somewhat smaller than the clear width B of the annular groove 2., and the inner diameter d at the rear edge 9 of the drive band is somewhat smaller than the major diameter D of the projectile jacket.
  • the driving band 3 must be forced over the rearward end of the projectile until the rear edge 9 of the driving band snaps into the annular groove 2. This operation is faciltated by the tapered base surface 8 of the driving band.
  • the present invention has been directed particularly to a projectile having a caliber of 20 mm. (0.7874 inch) and the proportion of such projectile are reflected in FIGURE 4.
  • the acute angle included between the base wall 4 of the annullar groove 2 and the longitudinal axis 15 of the projectile is preferably about 10.
  • the ratio of the clear width B of the annular groove to its depth f is about 1:05, with the clear width B or the annular groove being about 5 mm. (0.19685 inch) and the depth 1 of the annular groove being approximately 2.2 mm. (0.0866 inch).
  • the guide ring 3 is beveled on its outer sides at 16 and 17, with the inclination of these annular surfaces 16 and 17 toward the longitudinal axis of the projectile preferably being about 25.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Toys (AREA)
  • Snaps, Bayonet Connections, Set Pins, And Snap Rings (AREA)
US725244*A 1964-10-24 1968-02-06 Projectile with sintered metal driving band Expired - Lifetime US3460478A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DER39092A DE1243055B (de) 1964-10-24 1964-10-24 Geschoss mit einem in eine Ringnut eingepressten Fuehrungsring

Publications (1)

Publication Number Publication Date
US3460478A true US3460478A (en) 1969-08-12

Family

ID=7405688

Family Applications (1)

Application Number Title Priority Date Filing Date
US725244*A Expired - Lifetime US3460478A (en) 1964-10-24 1968-02-06 Projectile with sintered metal driving band

Country Status (9)

Country Link
US (1) US3460478A (de)
BE (1) BE671271A (de)
CH (1) CH444717A (de)
DE (1) DE1243055B (de)
DK (1) DK125558B (de)
ES (1) ES318813A1 (de)
GB (1) GB1092318A (de)
NL (1) NL6513597A (de)
NO (1) NO115724B (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3786760A (en) * 1972-06-01 1974-01-22 Pacific Technica Corp Rotating band for projectile
US5198616A (en) * 1990-09-28 1993-03-30 Bei Electronics, Inc. Frangible armor piercing incendiary projectile
US20040045671A1 (en) * 2002-09-10 2004-03-11 Ed Rejda Selective etching device
US6769364B2 (en) * 2001-11-23 2004-08-03 Rheinmetall W & M Gmbh Full-caliber projectile
US6782830B1 (en) * 2003-09-11 2004-08-31 Alliant Techsystems Inc. Obturator for large caliber smooth bore ammunition
WO2015183371A3 (en) * 2014-03-10 2016-04-14 Nostromo, Llc Ammunition cartridge with induced instability at a pre-set range

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE441305B (sv) * 1979-03-07 1985-09-23 Bofors Ab Sett att festa en projektils gordel medelst friktionssvetning
DE3334023A1 (de) * 1983-09-21 1985-04-04 Mauser-Werke Oberndorf Gmbh, 7238 Oberndorf Geschosskoerper mit kunststoffuehrungsband

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US681448A (en) * 1899-03-16 1901-08-27 Gathmann Torpedo Gun Company Projectile.
US725385A (en) * 1902-06-03 1903-04-14 Firth Stirling Steel Company Projectile.
US815992A (en) * 1904-08-01 1906-03-27 Firth Sterling Steel Co Projectile and its band.
US1475578A (en) * 1918-04-25 1923-11-27 Hadfield Robert Abbott Projectile
FR748006A (fr) * 1932-12-23 1933-06-27 Anciens Ets Hotchkiss & Cie Perfectionnements aux projectiles pour canons, mitrailleuses, etc.
US2411073A (en) * 1944-08-16 1946-11-12 Isthmian Metals Inc Making products of iron or iron alloys
US2856856A (en) * 1955-06-02 1958-10-21 Louis S Michael Segmented rotating band for artillery projectiles

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2996012A (en) * 1955-11-17 1961-08-15 Rex B Butler Rotating band and seat therefor

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US681448A (en) * 1899-03-16 1901-08-27 Gathmann Torpedo Gun Company Projectile.
US725385A (en) * 1902-06-03 1903-04-14 Firth Stirling Steel Company Projectile.
US815992A (en) * 1904-08-01 1906-03-27 Firth Sterling Steel Co Projectile and its band.
US1475578A (en) * 1918-04-25 1923-11-27 Hadfield Robert Abbott Projectile
FR748006A (fr) * 1932-12-23 1933-06-27 Anciens Ets Hotchkiss & Cie Perfectionnements aux projectiles pour canons, mitrailleuses, etc.
US2411073A (en) * 1944-08-16 1946-11-12 Isthmian Metals Inc Making products of iron or iron alloys
US2856856A (en) * 1955-06-02 1958-10-21 Louis S Michael Segmented rotating band for artillery projectiles

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3786760A (en) * 1972-06-01 1974-01-22 Pacific Technica Corp Rotating band for projectile
US5198616A (en) * 1990-09-28 1993-03-30 Bei Electronics, Inc. Frangible armor piercing incendiary projectile
US6769364B2 (en) * 2001-11-23 2004-08-03 Rheinmetall W & M Gmbh Full-caliber projectile
US20040045671A1 (en) * 2002-09-10 2004-03-11 Ed Rejda Selective etching device
US6782830B1 (en) * 2003-09-11 2004-08-31 Alliant Techsystems Inc. Obturator for large caliber smooth bore ammunition
WO2015183371A3 (en) * 2014-03-10 2016-04-14 Nostromo, Llc Ammunition cartridge with induced instability at a pre-set range
US9952024B2 (en) 2014-03-10 2018-04-24 Nostromo Holdings, Llc Ammunition cartridge with induced instability at a pre-set range

Also Published As

Publication number Publication date
ES318813A1 (es) 1966-06-16
NO115724B (de) 1968-11-18
CH444717A (de) 1967-09-30
DE1243055B (de) 1967-06-22
NL6513597A (de) 1966-04-25
DK125558B (da) 1973-03-05
BE671271A (de) 1966-02-14
GB1092318A (en) 1967-11-22

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