US20120000390A1

US20120000390A1 - Discarding sabot for guide and method for attachment of such sabots

Info

Publication number: US20120000390A1
Application number: US12/673,478
Authority: US
Inventors: Thomas Heitmann
Original assignee: Rheinmetall Waffe Munition GmbH
Current assignee: Rheinmetall Waffe Munition GmbH
Priority date: 2007-08-09
Filing date: 2008-07-16
Publication date: 2012-01-05
Also published as: DE102007037700A1; KR20100068376A; EP2176621A1; WO2009018901A1

Abstract

To maintain predetermined tolerance conditions for the front guide region (7) of a guide sabot (5) in a simple manner without reconditioning, even if the drive or guide cage (5) is plastic, the invention begins with a premounted cage shot (1), i.e., a sabot projectile, wherein cage segments directly adjacent to one another on circumferential sides surrounding the shot body are selected so that the cage (5) has an outer diameter in the front guide region (7) that is less than the predetermined target diameter (Do). Adjustment of the diameter of the guide region (7) then occurs subsequently, for example, by the insertion of an insert (12.1) designed in the shape of a bushing, wherein the insert has a conical outer surface (13) and is placed into an annular gap (11) remaining between the shot body (2) and segments (19, 20) of a support wall (8) of the cage (5).

Description

This is a National Phase application in the United States of International Patent Application No. PCT/EP2008/005799 filed Jul. 16, 2008, which claims priority on German Patent Application No. DE 10 2007 037 700.4, filed Aug. 9, 2007. The entire disclosures of the above patent applications are hereby incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a discarding or guide sabot, and to a method for attachment of such sabots, in particular, for a blank projectile.

BACKGROUND OF THE INVENTION

A discarding-sabot projectile is known, for example, from DE 43 30 417 C2. This device comprises a sub-caliber projectile body and a discarding guide sabot, wherein the discarding sabot essentially comprises a drive disk, which is arranged at the rear and on which the rear area of the projectile body is supported, and two discarding sabot segments, which surround the projectile body and are in the form of half-shells. The discarding guide sabot has an externally circumferential projecting guide area in the front area and has a supporting wall in the front to central area of the projectile body, which supporting wall extends radially inward and has a central opening through which the projectile body projects. Both for weight reasons and for reasons of simple manufacture, the discarding guide sabot is preferably composed of a carbon-fiber, or glass-fiber-reinforced, plastic and can, therefore, be produced very cost-effectively in relatively large quantities by injection molding or compression molding.
However, during the production of such discarding-sabot projectiles composed of plastic, it has been found to be problematic to comply with the predetermined tight tolerances for the front guide area of the discarding sabot, by means of which the discarding-sabot projectile is supported on the inside of the corresponding weapon barrel. In the case of 120 mm tank munition, for example, the corresponding external diameter of the guide area should be between 119.65 and 119.83 mm, which is virtually impossible to achieve without costly reworking in the case of injection-molded parts, or compression-molded parts, composed of plastic.
The present invention is based on the object of specifying a discarding or guide sabot by means of which it is possible, in a simple manner, to comply with predetermined tolerance conditions, in particular, for the front guide area of the initially mentioned discarding-sabot projectiles, without reworking, to be precise even when the discarding or guide sabots are composed of plastic, and are produced by injection molding or compression molding.

SUMMARY OF THE INVENTION

According to the present invention, with regard to the sabots, this object is achieved by the features of a first embodiment, which pertains to a sabot projectile (1) having a discarding or guide sabot (5), which includes at least two sabot segments (3, 4), characterized in that an adjustment element (12) is included between the projectile body (2) and the sabot segments (3, 4). With regard to the method, the object of the invention is achieved by the features of a tenth embodiment, which pertains to a method for attachment of a sabot projectile to a sub-caliber projectile body (2) and to a segmented, essentially hollow-cylindrical, discarding or guide sabot (5), which has a circumferential guide area (7) in the front area and has a supporting wall (8) in the front to central area of the projectile body (2), which supporting wall (8) extends radially inward and has a central opening (9) through which the projectile body (2) projects, characterized in that (a) the projectile body (2) is first of all introduced into the sabot (5), wherein the sabot segments (3, 4) which are adjacent to one another on the circumferential side are chosen such that they are arranged such that they can be moved radially, and are in the pushed-together state, in which a front guide area (7) of the sabot (5) results, whose external diameter is less than a predetermined nominal-value diameter (Do) and in that an annular gap remains between the projectile body (2) and the inner surface (10) of the central opening (9) in the supporting wall (8), (b) an adjustment element (12, 12.1, 12.2) is then pushed into the annular gap (11) from the front face of the sabot (5), and (c) the adjustment element (12, 12.1, 12.2) is then fixed with a force fit in the annular gap (11) and the sabot segments (3, 4) of the sabot (5) are connected to one another with a force fit. Furthermore, particularly advantageous refinements of the invention are disclosed in the dependent embodiments.
For example, with respect to the apparatus embodiment of the invention, in accordance with a second embodiment of the invention, the sabot projectile according to the first embodiment is modified so that the sabot (5) has only two sabot segments (3, 4), which are in the form of half-shells. In accordance with a third embodiment of the present invention, the first embodiment and the second embodiment are further modified so that the adjustment element (12) is composed of a deformable plastic material. In accordance with a fourth embodiment of the present invention, the first embodiment, the second embodiment and the third embodiment are modified so that the adjustment element is an insert (12.1) in the form of a bush.
In accordance with a fifth embodiment of the present invention, the fourth embodiment is further modified so that the insert (12.1), which is in the form of a bush, is formed from one or more parts and has weak points in areas that are radially adjacent to the separating joints (18) of the two segments (19, 20) of the supporting wall (8). In accordance with a sixth embodiment of the present invention, the fourth embodiment or the fifth embodiment is further modified so that the insert (12), which is in the form of a bush, comprises two parts (15, 16) that are in the form of half-shells, wherein the separating joints (17) that are located between the two parts (15, 16) are radially adjacent to the separating joints (18) of the two segments (19, 20) of the supporting wall (8) of the sabot (5). In accordance with a seventh embodiment of the present invention, the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, and the fifth embodiment are further modified so that the insert (12) is in the form of a collar-type bush.
In accordance with an eighth embodiment of the present invention, the first embodiment is modified so that the adjustment element (12) is an attachment (12.2) which can be pushed on over the supporting wall (8) like a bracket or clasp. In accordance with a ninth embodiment of the present invention, the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, the sixth embodiment, the seventh embodiment, and the eighth embodiment are further modified so that the sabot segments (3, 4) are formed from plastic.
In accordance with method of an eleventh embodiment of the present invention, the tenth embodiment is modified so that, in order to match the diameter of the front guide area (7) to the nominal-value diameter (Do), the preassembled unit comprising the projectile body (2) and the sabot (5) is inserted in the area of the guide area (7) into an annular assembly tool, whose internal diameter corresponds to the nominal diameter (Do) of the guide area (7). In accordance with a twelfth embodiment of the invention, the tenth embodiment and the eleventh embodiment are further modified so that, in order to fix the adjustment element (12, 12.1, 12.2) with a force fit, it is adhesively bonded or welded to the supporting wall (8). In accordance with a thirteenth embodiment of the present invention, the tenth embodiment, the eleventh embodiment and the twelfth embodiment are further modified so that, in order to connect the sabot segments (3, 4) of the sabot (5) with a force fit, each of the sabot segments (3, 4) is provided on the circumferential side with at least one part (22), which is in the form of a lug and is adhesively bonded into a depression (23) in the corresponding adjacent sabot segment, or is connected thereto by means of a welded joint.
In accordance with a fourteenth embodiment of the present invention, the tenth embodiment, the eleventh embodiment, the twelfth embodiment, and the thirteenth embodiment of the present invention are further modified so that, when an insert (12.1) in the form of a bush is used as the adjustment element (12), it is pushed into the annular gap (11) until the external diameter of the front guide area (7) corresponds to the predetermined nominal-value diameter (Do) as a result of the segments (19, 20) of the supporting wall (8), which are supported on the insert (12.1), are pushed apart from one another. In accordance with a fifteenth embodiment of the present invention, the tenth embodiment, the eleventh embodiment, the twelfth embodiment and the thirteenth embodiment are further modified so that, when an attachment (12.2) in the form of a bracket or clasp is used as the adjustment element (12), the attachment (12.2) is deformed between the sabot segments (3, 4) and the projectile (2) by an assembly tool that is pulled over it.
In other words, the invention is essentially based on the idea of using a preassembled discarding or guide sabot in which the drive or guide segments, which directly adjoin one another on the circumferential side and surround the projectile body, are chosen such that, in the front guide area, the sabot has an internal diameter that is somewhat larger than the external diameter of the dart projectile, and such that an annular gap remains between the projectile body and the inner surface of the central opening. On the basis of this preassembled discarding-sabot projectile, the diameter of the guide area is then set to the predetermined nominal value by introducing a so-called “adjustment element” into the annular gap from the front face of the discarding guide sabot.
In order to accurately adjust the diameter of the front guide area, the preassembled unit can be inserted in the area of the guide area into an annular assembly tool (caliber adjustment tool), whose internal diameter corresponds to the predetermined nominal-value diameter of the guide area. The adjustment element can be fixed with a force fit in the central opening by means of an adhesive or welded joint between the adjustment element and the supporting wall.
In order to connect the sabot segments of the sabot to one another with a force fit, each of the sabot segments may be provided on the circumferential side with at least one part, which is in the form of a lug and is adhesively bonded into a corresponding depression in the respectively adjacent sabot segment, or is likewise connected thereto by means of a welded joint.
In one preferred embodiment to the invention, the sabot projectile produced using the method according to the invention is a projectile whose sabot preferably has only two sabot segments, which are in the form of half-shells. The adjustment element is preferably composed of a deformable plastic material, as a result of which this material deforms while being pushed slowly into the annular gap and is thus matched without any tolerances to the contours of the projectile body and of the sabot segments (i.e., segments of the supporting wall).
An insert, which is in the form of a bush and has a conical outer surface, can be used as the adjustment element. The insert, which is in the form of a bush, may comprise two parts that are in the form of half-shells, wherein the separating lines that are located between the two parts are radially adjacent to the separating lines of the two halves of the supporting wall of the discarding-sabot segments. However, it may also be formed integrally and may have weak points in the areas that are radially adjacent to the separating lines of the two halves of the supporting wall of the discarding-sabot segments. The insert is pushed into the annular gap until the external diameter of the front guide area corresponds to the predetermined nominal-value diameter as a result of the segments of the supporting wall of the discarding sabot, which are supported on the insert, being pushed apart from one another. Then, not only is the adjustment element fixed with a force fit in the annular gap, but the sabot segments of the sabot are also connected to one another with a force fit.
It has been found to be advantageous for the insert to be in the form of a collar-type bush, which results in axial movement of the insert being limited by the collar.
Alternatively, the adjustment element may be formed by a highly deformable silicone rubber (Shore 40), which flexes to match the contours of the supporting wall of the guide sabot and, on the one hand, surrounds the supporting wall from the top and bottom, while, on the other hand, pressing against the projectile. The attachment, in the form of a bracket or clasp, is deformed between the half-shells and the projectile by the assembly tool being pulled over it.
One major advantage of the use of deformable plastic material (for example, rubber) for the adjustment elements is that there is no longer any need for mechanical reworking, and the tolerances of the shaping tool can be individually matched to the sabot projectile, and the shaping tool itself need no longer be designed with such high precision.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details and advantages of the invention will become evident from the following exemplary embodiments, which are explained in the figures, in which:

FIG. 1 shows the longitudinal section through a discarding or guide sabot projectile according to the invention, in which the sabot segments of the sabot have already been pushed sufficiently far apart from one another that the front guide area of the sabot has a predetermined nominal-value diameter;

FIG. 2 shows a cross section through the sabot projectile as illustrated in FIG. 1, along the section line annotated II-II;

FIG. 3 shows a section along the section line annotated III-III in FIG. 2; and

FIG. 4 shows a perspective illustration of the sabot projectile illustrated in FIG. 1;

FIG. 5 shows a further variant of an adjustment element in accordance with the present invention; and

FIG. 6 shows the insertion of the adjustment element from FIG. 5 into the discarding-sabot projectile.

DETAILED DESCRIPTION OF THE INVENTION

In FIGS. 1 and 4, 1 denotes a discarding-sabot projectile which, for example, is a 120 mm tank projectile that acts as a so-called discarding sabot (alternatively, however, it could also be a discarding sabot). The sabot projectile 1 has a sub-caliber projectile body 2, and an essentially hollow-cylindrical guide sabot 5, which comprises two half-shells (guide sabot segments) 3, 4. A drive disk (pusher plate) 6 is provided in the rear area in the guide sabot 5, and the projectile body 2 is supported on it at the rear.
The guide sabot 5 is composed, for example, of plastic and, in its front area has a circumferential guide area 7, which projects on the outside, for support on the barrel inner wall of a weapon barrel, which is not illustrated. A (segmented) supporting wall 8 is also provided in the front area of the guide sabot 5, wherein the supporting wall 8 extends radially inward and has a central opening 9 through which the projectile body 2 is passed.
There is an annular gap 11 between the inner surface 10 of the central opening 9 in the supporting wall 8 and the projectile body 2, in which an annular gap insert 12.1 which is in the form of a bush, is pushed as an adjustment element 12, composed of a highly deformable plastic material with a conical outer surface 13 and a collar 14, and is connected with a force fit to the supporting wall 8 (c.f., also FIG. 3). In this case, the insert 12.1, which is in the form of a bush, comprises two parts 15, 16 (FIG. 2) that are in the form of half-shells, wherein the separating joints 17, which are located between the two parts 15 and 16, are radially adjacent to the separating joints 18 of the two segments 19, 20 of the supporting wall 8 (See FIG. 4).
In order to the set the external diameter of the guide area 7 very precisely to the predetermined nominal value, the sabot segments 3, 4 are chosen such that they are arranged so that they can be moved radially (before they are connected to one another with a force fit) and, in the pushed-together state (that is to say before the insert is inserted into the annular gap), have an external diameter (of, for example, 119.7 mm) in the front guide area 7, which is less than the predetermined nominal-value diameter Do (of, for example, 119.8 mm).
The external diameter of the guide area 7 is then adjusted precisely so that the insert 12.1, which is in the form of a bush, is inserted into the relatively narrow annular gap 11 from the front face of the guide sabot 5, and is moved axially until the external diameter of the front guide area corresponds to the predetermined nominal-value diameter Do as a result of the segments 19, 20 of the supporting wall 8, which are supported on the insert 12.1, being pushed apart from one another. For this purpose, the front guide area 7 can be inserted into an annular assembly tool (not illustrated), whose internal diameter corresponds to the nominal diameter Do of the guide area 7.
The insert 12.1 is then connected to the supporting wall 8, and the sabot segments 3, 4 are connected to one another, in both cases with a force fit, for example, by means of an adhesive joint. In order to produce the force-fitting connection of the sabot segments 3, 4 of the guide sabot 5, each of the sabot segments 3, 4 is provided on the circumferential side with a part 22 that is in the form of a lug, and is adhesively bonded or welded into a depression 23 in the corresponding adjacent sabot segments 4, 3.
Alternatively, as shown in FIG. 5, the adjustment element 12, as a bracket-like or clasp-like attachment 12.2, can be pushed on over the supporting wall 8, thus filling the narrow annular gap 11. The attachment 12.2 has a shape that is matched to the supporting wall 8, with a lower and an upper surface 12.2.1, 12.2.2, respectively, surrounding the supporting wall 8, while the part 12.2.3, which is located between the two faces 12.2.1, 12.2.2, is pressed against the projectile 2 (FIG. 6).
The attachment 12.2 presses the sabot half- shells 3, 4 outward. As a result of the caliber adjustment tool being pulled over it (not illustrated in any more detail), the attachment 12.2 is deformed between the half- shells 3, 4 and the projectile 2. The half- shells 3, 4 are then firmly connected to one another. Like the insert 12.1, this attachment 12.2 is also preferably formed from two or more parts.
The insert 12.1, or attachment 12.2, that is to say the adjustment element 12, furthermore, has good damping characteristics as a shaping element when passing through a barrel.
Alternatives for the connection of the half-shells or sabot segments 3, 4 would be to use bolts, which are flanged over and/or welded, or a screw connection provided with weak points, or the use of additional elements, such as adhesive lugs.

LIST OF REFERENCE SYMBOLS

1 Discarding or guide sabot projectile
2 Projectile body
3, 4 Half-shells, sabot segments
5 Discarding or guide sabot
6 Drive disk
7 Guide area
8 Supporting wall
9 Central opening
10 Inner surface
11 Annular gap
12 Adjustment element
12.1 Insert
12.2 Attachment
13 Outer surface
14 Collar
15, 16 Parts
17 Separating joint (of insert)
18 Separating joint (of supporting wall)
19, 20 Segments
22 Part in the form of a lug
23 Depression

Claims

1. A sabot projectile having a discarding or guide sabot, wherein the discarding or guide sabot comprises:

(a) at least two sabot segments;

(b) a projectile body; and

(c) an adjustment element included between the projectile body and the sabot segments.

2. The sabot projectile as claimed in claim 1, wherein the sabot has only two sabot segments, and each of the two sabot segments are in the form of half-shells.

3. The sabot projectile as claimed in claim 1, wherein the adjustment element comprises a deformable plastic material.

4. The sabot projectile as claimed in claim 1, wherein the adjustment element is an insert in the form of a bush.

5. The sabot projectile as claimed in claim 4, wherein the insert in the form of a bush is formed from one or more parts and has weak points in areas that are radially adjacent to separating joints of two segments of a supporting wall.

6. The sabot projectile as claimed in claim 5, wherein the insert that is in the form of a bush comprises two parts that are in the form of half-shells, wherein separating joints that are located between the two parts are radially adjacent to the separating joints of the two segments of the supporting wall of the sabot.

7. The sabot projectile as claimed in claim 4, wherein the insert is in the form of a collar-type bush.

8. The sabot projectile as claimed in claim 1, wherein the adjustment element is an attachment that can be pushed on over a supporting wall to serve as a bracket or clasp.

9. The sabot projectile as claimed in claim 1, wherein the at least two sabot segments are formed from plastic.

10. A method for attachment of a sabot projectile to a sub-caliber projectile body and to a segmented, essentially hollow-cylindrical, discarding or guide sabot, wherein the discarding or guide sabot has a circumferential guide area in a front area and has a supporting wall in a front-to-central area of the projectile body, wherein a supporting wall extends radially inward and has a central opening through which the projectile body projects, wherein the method comprises the steps of:

(a) first, introducing—the projectile body into the sabot, wherein sabot segments that are adjacent to one another on a circumferential side are chosen and arranged so that the sabot segments are radially moveable and are in a pushed-together state, wherein a front guide area of the sabot results and has an external diameter that is less than a predetermined nominal-value diameter, and an annular gap remains between the projectile body and an inner surface of the central opening in the supporting wall;

(b) then pushing—an adjustment element into the annular gap from a front face of the sabot; and

(c)—then fixing the adjustment element with a force fit in the annular gap and the sabot segments of the sabot are connected to one another with a force fit.

11. The method as claimed in claim 10, wherein, in order to match a diameter of the circumferential guide area to the nominal-value diameter, a preassembled unit comprising the projectile body and the sabot is inserted in an area of the circumferential guide area into an annular assembly tool, wherein an internal diameter of the annular assembly tool corresponds to the nominal-value diameter of the circumferential guide area.

12. The method as claimed in claim 10, wherein, in order to fix the adjustment element with a force fit, the adjusting element is adhesively bonded or welded to the supporting wall.

13. The method as claimed in claim 10, wherein, in order to connect the sabot segments of the sabot with a force fit, each of the sabot segments is provided on the circumferential side with at least one part that is in the form of a lug and is adhesively bonded into a depression located in a corresponding adjacent sabot segment, or is connected thereto by a welded joint.

14. The method as claimed in claim 10, wherein, when the adjustment element is an insert in the form of a bush, the insert is pushed into the annular gap until an external diameter of the circumferential guide area corresponds to the predetermined nominal-value diameter as a result of pushing the segments of the supporting wall that are supported on the insert apart from one another.

15. The method as claimed in claim 10, wherein, when the adjustment element is an attachment in the form of a bracket or clasp, the attachment is deformed between the sabot segments and the projectile by an assembly tool that is pulled over the attachment.

16. The sabot projectile as claimed in claim 2, wherein the adjustment element comprises a deformable plastic material.