GB2237622A

GB2237622A - Gun barrel mounting

Info

Publication number: GB2237622A
Application number: GB9016303A
Authority: GB
Inventors: Wilfried Becker; Wolfgang Arrenbrecht
Original assignee: Rheinmetall GmbH
Current assignee: Rheinmetall Industrie AG
Priority date: 1989-11-02
Filing date: 1990-07-25
Publication date: 1991-05-08
Also published as: DE3936454A1; FR2653871A1; GB9016303D0

Abstract

A gun barrel 10 is mounted in an axially displaceable manner in a cradle or in a cradle tube 18 for recoil damping. To avoid jump on firing the gun barrel 10 is provided with lateral guide elements 20 to position the barrel vertically and which are situated on the sides of the gun barrel 10 and upper and lower guide elements 20, which are mounted at the top and the bottom of the gun barrel 10 and which position the barrel horizontally. The guide elements engage recesses 22 in the cradle tube 18 and allow longitudinal recoil movement as well as accommodating radial expansion on firing the barrel. The guide elements 20 may be made removable and replaceable following wear. Alternatively recesses 22 in the barrel 10 are engaged by parts of the cradle tube 18. <IMAGE>

Description

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1 - T ITLE Gun Barrel Mounting This invention relates to a gun barrel mounting which enables a return movement of the barrel to take place to absorb recoil, the barrel being mounted in a longitudinally displaceable manner on a cradle or in a cradle tube.

Known gun barrel mountings for use with a cradle tube produce barrel "jump" by causing a lifting of the barrel. This lifting effect is produced by the high gas pressure which suddenly occurs in the barrel when ammunition is fired. The pressure rise taking place in the breech of the gun barrel causes a sudden expansion in this zone and at a rear supporting point the gun barrel is thus suddenly lifted by a large vertical impulse. This causes undesirable transverse flexural vibrations in the barrel. As soon as the projectile passes the front supporting point of the gun barrel in the cradle tube, the gas pressure causes a similar effect at this point as well, with the corresponding introduction of a sudden vibrating impulse into the internal liner or gun barrel.

DE 23 49 720 discloses a cradle mounting for a weapon Pivotable vertically and laterally. This 1 2 - 0 W 40820/wsy arrangement, however, is only suitable for small calibre weapons, such as machine guns, and not for large calibre tank guns, for example of 120mm calibre, wherein the known cardanic suspension of the cradle precludes a longitudinal return movement of the gun barrel.

Heavy tank guns or their barrels are usually mounted in the turret of the tank in such a way that they can only be elevated, this being done by means of a trunnion system flange-connected to the cradle tube. To move the gun in the horizontal plane the entire turret has to be rotated.

This invention seeks to provide a means by which a gun barrel can be mounted within a cradle or a cradle tube avoiding the lift effect and being suitable for use with heavy tank guns.

According to this invention there is provided a gun barrel mounting comprising a gun barrel coaxially located and mounted within a cradle tube by guide elements allowing longitudinal recoil absorption movement, an annular gap being provided between the barrel and cradle tube to permit radially expansion of the barrel on firing, the guide elements permitting free radial movement.

According to this invention there is also provided gun barrel mounting wherein the barrel is mounted for 1 f 3 - 40820/wsy recoil damping in a longitudinally displaceable manner in a cradle or cradle tube, the barrel having longitudinal lateral guide elements forming a vertical location system and longitudinal upper and lower guide elements forming a horizontal location system, said systems supporting and allowing free longitudinal movement of the barrel within the cradle or cradle tube, said systems further allowing for radial expansion movement of the barrel.

In the barrel mounting system according to this invention the lift effect is avoided as a result of the fact that the horizontal and vertical expansion of the barrel is unimpeded as the barrel does not encounter any fixed stop in the radial direction. The bearing force and the radial expansion of the barrel are thus always at right angles to each other.

The barrel mounting system according to the invention ensures that the liner (gun barrel), in the event of a sudden partial expansion caused by the internal gas pressure, will not undergo an additional dynamic bearing force leading to jerky vibrations of the barrel in the vertical and/or horizontal direction. The degree of freedom required in the longitudinal direction for the return movement of the barrel is not impaired by the measure taken in the invention.

The invention is explained further and described in L5 M 4 - 40820/wsy more detail with reference to constructional embodiments illustrated schematically in the drawings by way of examples. In the drawings:Figure 1 shows a cross-section showing the effect of the lift on a known gun barrel during the firing operation, Figure 2 shows the mounting of a gun barrel in a cradle tube according to this invention, Figure 3 shows to a larger scale a guide system between the cradle tube and the gun barrel according to this invention, and Figure 4 shows a further guide system for gun barrel and cradle tube according to this invention.

In Figure 1 a gun barrel 10 is supported from below against a fixed bearing 12 shown schematically. The fixed bearing 12 is usually part of a cradle or of a cradle tube 18 (Figure 2). The gun barrel 10 is mounted in a longitudinally movable manner in the cradle tube 18 in order to enable the barrel to perform a return movement which damps the recoil.

On the firing of the projectile the gun barrel 10 suddenly expands by an amount d(r). Owing to the fact that the barrel is supported against the fixed bearing 12 - 40820/wsy the barrel 10 "jumps" or rises by an amount 2d(r). This lift effect 16 leads to undesirable vibrations in the barrel.

In order to eliminate these vibrations this invention provides that the barrel should be mounted in the cradle tube 18 in a lift-free manner as shown in Figure 2. For this purpose the gun barrel 10 is provided at each side and above and below with guide elements 20 which extend in a longitudinal direction and which engage corresponding recesses 22 or longitudinal grooves in the cradle tube in such a way as to be freely movable radially and also in a longitudinal direction of the tube.

The guide elements 20 are advantageously constructed as bars forming slide rails, preferably of rectangular cross section. The slide rails may comprise, for example, plastic such as PVC, teflon or a similar substance or take the form of plastic-coated steel runners.

In Figure 3 the arrow 24 shows the longitudinal mobility of the gun barrel 10 (recoil on firing) inside the cradle tube 18. Between the cradle tube 18 and the gun barrel 10 an annular space 26 is left free, so that the barrel can expand unimpeded in the radial direction. A free space 26 is also provided in the radial direction 6 40820/wsy in each of the recesses 22 for the guide elements 20. The barrel can thus expand vertically and horizontally without hindrance, the direction taken by the bearing force being at right angles to that in which the barrel expands radially.

The lifting effect is equal to zero (see arrows in Figure 2) also showing how the barrel is located in the horizontal and vertical planes.- Figure 4 shows a further preferred embodiment of the invention where the recesses 22 contain appropriate Ushaped liners 28 of a bearing material with good sliding properties such as a plastic, for example teflon, PVC or a similar substance, copper, bronze, lead impregnated sinter iron or a similar material.

It may likewise be of advantage for the guide elements 20 forming slide rails and/or the liners 28 in the recesses 22 forming a longitudinal groove to be removable and replaceable following wear to the gun barrel 10 and/or cradle tube 18.

Figures 2 and 3 show a version of the invention in which the guide elements 20 are affixed to the gun barrel and the corresponding recesses 22 are formed inside the cradle tube 18.

In this case the guide elements 20 may be affixed to the gun barrel as Trails, so that they can be detached - 7 40820/wsy (unscrewed) therefrom, or else formed from the barrel 10 in one piece therewith (in which case they are not detachable). In the case of non- detachable guide elements on the gun barrel 10, removable and replaceable U-shaped liners 28 should then be provided in the recesses 22 in the cradle tube 18.

From the illustration in Figure 4 it can be seen that the recesses 22, possibly with liners 28, are formed on the gun barrel, while the guide elements 20 are detachably or interchangeably affixed to the cradle tube 18. According to the constructional version used and the temperatures to be resisted the guide elements 20 and/or the wear liner 28 can be affixed to the components concerned, that is to the gun barrel or cradle tube, by an adhesive, soldering, brazing, spot welding, screw connections or special keying or strainer screws.

In the case of smaller weapons with a short barrel it may be desirable for the guide elements on the latter to extend over the entire length of the cradle tube. In the case of larger weapons with a comparatively long cradle tube, on the other hand, it may be of advantage for the guide elements to be confined to certain zones, preferably a front and rear zone, or to a number of zones of that part of the gun barrel which is situated inside the cradle tube.

8 - 40820/wsy This invention thus provides a simple and economical method of supporting a gun barrel allowing a recoil action without the undesirable jump effect which has occurred hitherto and which causes barrel vibrations.

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Claims

40820/wsy 1. Gun barrel mounting comprising a gun barrel coaxially located and mounted within a cradle tube by guide elements allowing longitudinal recoil absorption movement, an annular gap being provided between the barrel and cradle tube to permit radial expansion of the barrel on firing, the guide elements permitting free radial movement.
2. Gun barrel mounting wherein the barrel is mounted for recoil damping in a longitudinally displaceable manner in a cradle or cradle tube, the barrel having longitudinal lateral guide elements forming a vertical location system and longitudinal upper and lower guide elements forming a horizontal location system, said systems supporting and allowing free longitudinal movement of the barrel within the cradle or cradle tube said systems further allowing for radial expansion movement of the barrel.
3 3. Gun barrel mounting in accordance with Claim 1, or 2 wherein the guide elements comprise grooves engaged by sliding rails of rectangular cross section.

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4. Gun barrel mounting in accordance with Claim 1, 2, or 3 wherein the guide elements include inserts of a low friction bearing material.
5. Gun barrel mounting in accordance with any preceding claim wherein the guide elements and/or the inserts are removably and replaceably secured to the gun barrel and/or the cradle tube.

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6. Gun barrel mounting in accordance with any preceding claim, wherein the guide elements comprise parts secured to the gun barrel engaging recesses in the cradle tube.
7. Gun barrel mounting in accordance with Claim 6, wherein said parts of the guide elements are integral with the gun barrel forming a one piece structure therewith.
8. Gun barrel mounting in accordance with any preceding Claim 1 to 5, wherein the guide elements comprise recesses in the gun barrel engaged by parts of the cradle tube.

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9. Gun barrel mounting in accordance with any preceding claim, wherein parts forming the guide elements extend c 11 - 40820/wsy the entire length of the cradle tube or the barrel or both.
10. Gun barrel mounting in accordance with any preceding Claims 1 to 8, wherein parts forming the guide elements are provided in two zones at the front and rear of the cradle tube.
11. Gun barrel mounting in accordance with Claim 10, wherein said parts forming the guide elements are provided in a number of discrete zones along the cradle tube.
12. Gun barrel mounting constructed and arranged to function as described herein and exemplified in the drawings.

Published 1991 atThe Patent Office. State House. 66/71 High Holborn. London WC I 1141P. Further copies may be obtained from Sales Branch. Unit 6. Nine Mile PoinL Cwmfelirifach. Cross Keys, Newport. NPI 7HZ. Printed by Multiplex techniques lid. St Mary Cray. Kent.