DE1703012A1 - Twist profile for floor run - Google Patents

Description

^ _n ■■■ I / UOU J ^ 33 BRAUNSCHWEIG, March 20

DR.-ING. HELMUT JOOSS theodor-heuss-strasset

DIPL-ING. WERNER GRAM Ruf23430,28039

Engineer Karl B u r g s m ü 1 1 e r Kreiensen / Harz, Haus Hainberg

^ir twist profile for storey barrels "

Patent honor ibung. -

The invention is based on the knowledge that a conventionally designed twist tension profile of a projectile barrel has the following deficiencies in particular:

1. The so-called twist gives the projectile known ^ the energy for its rotation necessary for stabilization in the IFr eleven lug ". Since the projectile mass is also in relation would like to insist on the rotational movement in rest, it comes through on the active flanks of the conventional profile a kind of wedge effect to radially directed components, which the run there especially at the beginning of the acceleration seek to expand the projectile elastically. According to the inventor's plague, the reason for this lies in that the angle between the bore radius and the

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Twist flank, which is sometimes praised as having an additional projectile centering effect, is unfavorably large is.

2. In addition, the usual twisted tension profile causes the energy for the rotation of the bullet through this very mediation and by the already mentioned wedge effect due to the unfavorably large pressure angle of approx. 35 ° and more a high braking torque on its flanks during the rotating acceleration of the projectile. This leaves the gas pressure rise high and consume its energy to an unnecessarily high level. This additional friction contributes to the erratic Heating of the barrel and therefore considerably reducing the regularity from shot to shot.

3 · In addition, the well-known twisted tension profile promotes through the tangential compression of the projectile or projectile jacket that inevitably occurs when the rotational forces are imparted on the active flanks, the emergence of a light gap with a cross-section rhombic shape on the passive ones Flanks through which part of the hot propellant gas slips. The barrel material and the projectile material are this heats up and corrodes here. Melted material

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Particles are thrown into the barrel, which are then smeared onto the inner surface of the barrel by the projectile passing over it. This causes the projectile to roll axially and the barrel to vibrate accordingly. This reduces the precision of the barrel and also varies the speed of the projectile trajectory. %

Finally, a twisted tension profile prevents the for reasons the more convenient production of the usual straight-split number of trains, especially when - as practice always wants Bore is not accommodated absolutely concentrically in the barrel or the material is structured by multiple straightening became different within production, the uniform contact of all field flanks with the corresponding ones Floor areas. The unequal wall thickness or unequal ^ Fixed running then expands under the action of the reaction forces from the rotation mediation, as is well known by the gas pressure itself, more elastic on the weaker wall than on the stronger one. The leadership on the field flanks becomes asymmetrical, and with the resulting different gas slip and the gas that is dependent on it— Druckyerlauf results in a bullet rolling and barrel swing in the radial direction. This also makes the exit

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Gangstonkel affects what is sensitive to the Can affect the accuracy of the barrel.

A four-part or even multi-part train arrangement practically cannot be brought into uniform, load-bearing contact with the corresponding storey surfaces, like a four-legged or multi-legged rigid table hardly ever free of play with all legs on the floor may have.

These disadvantages are thereby made according to the invention avoided that the lying between the fields and the trains helical twist flank surfaces with the respective on At the foot of the flank, the applied radius is a self-locking angle that the radial component acting on the tube wall from the mediation of the projectile rotational energy is possibly small holds, with / les it is advantageous that the barrel aufweißt three trains.

In addition, it is useful that the trains in cross section from the foot of their flank over about 90 ° about half the nominal caliber corresponding circular arc around the axis of the course and then run roughly along a flat Archimedean spiral or a parabolic section to the apex of the next flank.

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An exemplary embodiment is shown in the drawing of the invention shown.

Then a gun barrel 1 is provided with three pulls 2. Their active flanks 3, with the corresponding radii, form small, small angles / 5 of only about ⁵⁰ V, as is decisive for self-locking between the materials M under consideration here.

In cross section, the trains 2 run from the foot 7 of their Flank 3 over approximately 90 ° to point 6 approximately after one half the nominal caliber arc around the Running axis and then approximately after a flat Archimedean spiral or a parabolic section to the vertex 5 of the next flank.

The angles / 2 are kept so small that they are still sufficiently effective for centering, but cannot cause any components causing the expansion of the barrel from the reaction forces occurring at the flanks 3. You also avoid unnecessary decelerations of the projectile. Accordingly, they allow the gas pressure curve to rise less rapidly during the forces that are initially particularly high for mediating the bullet rotation.

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This makes the gas pressure curve more aggressive even "with" use Powder steadier but flatter.

This means that the projectile now has a higher initial speed and now also an energy-saving one in the area of rotary projectile acceleration lower helix angle can be used. This even makes the use of a progressive twist, which is superfluous difficult to produce.

Finally, the height of the flanks 3 can also be passed through the elimination of the component that otherwise elastically expands the barrel dimensioned less than with the conventional profile, even if instead of the usual four or more, only three twisted pulls are provided. However, these enlarge together with their novel Cross-sectional shape reduces the projectile area exposed to gas pressure by about 6%. This gives rise to other notable ballistic Advantages. ·

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Claims (3)

Claims. \ 1 ·) Twist pull profile for projectile barrels, characterized in that the helical twist flank surfaces C3) lying between the lower and the pulls (2 ) form a self-locking angle (/ o ) with the radius (4-) at the root of each flank, 'which the Keeping the radial component from the projectile rotational energy acting on the tube wall as small as possible. 2. twisted tension profile according to claim 1, characterized in that the barrel (1) has three trains (2). 3. twisted tension profile according to claim 1 or 2, characterized in that that the trains (2) in cross section from the foot (7) of their flank (3) over about 90 ° approximately after half the nominal caliber corresponding circular arc around the axis of the barrel (1) and then approximately after a flat Archimedean spiral or a parabolic section to the apex (5) of the next flank. Dr.J / Bo. Dr.-Ing. Jiooß Dipl.-Ing. Gram Patent attorneys 0 0983 5/00 5 7 Blank page