US2770988A

US2770988A - Misfired projectile extractor

Info

Publication number: US2770988A
Application number: US368559A
Authority: US
Inventors: Jasse Joseph Raymond
Original assignee: BRANDT SOC NOUV ETS
Current assignee: NOUVELLE des Ets BRANDT Ste; BRANDT SOC NOUV ETS
Priority date: 1952-07-24
Filing date: 1953-07-17
Publication date: 1956-11-20
Anticipated expiration: 1973-11-20
Also published as: GB734641A; FR1060600A; BE521299A; CH312246A; NL89896C; NL180034B

Description

Nov. 20, 1956 J. R. JASSE 2,770,988

MISF'IRED PROJECTILE EXTRACTOR Filed July 17, 1953 2 Sheets-Sheet 1 Nov. 20, 1956 J. R. JASSE 2,770,988

MISFIRED PROJECTILE EX'IIRACTOR Filed July 17, 1953 2 Sheds-Sheet 2 "I, "in

.ToJefl, Xay m Z155? United States Patent MISFIRED PROJECTILE EXTRACTOR Joseph Raymond Jasse, Paris, France, assignor to Societe Nouvelle des Etablissements Brandt, Paris, France, a French body corporate Application July 17, 1953, Serial No. 368,559 Claims priority, application France July 24, 1952 3 Claims. (Cl. 81--3.05)

The present invention relates to the extraction of a projectile that, after a misfire, remains in the tube of a anortar or like gun which is loaded from the nozzle en At thepresent time, the usual method of extracting the projectile consists in removing the fuse of the projectileand'replacing this fuse by a metal piece which is screwed on the projectile. A metal tube is then connectedto this piece and is drawn out of the mortar tube by means of two laterally extending rods. This procedure is. somewhat delicate and dangerous and requires about five minutes. i

The invention has for its object toprovide anextracting device which is simple in construction, particularly easy to use, and absolutely safe, and which permits a projectile that remains in the tube of a mortar or other gun after a misfire to be rapidly extracted.

The invention has more particularly for its object to provide an extracting device which comprises in combination: firstly, a grapple device formed of an annularbody having outer dimensions that substantially. correspond to the calibre of said tube so as to ensure the guiding thereof in the latter, the central aperture of said body being so adapted as to surround the fuse of the projectile without touching this fuse even when the wall of this aperture enters into contact with the projectile, several pawls pivotally mounted on transverse pivot pins in slots provided in said body, and elastic means acting on these pawls in such manner that one of the ends of each pawl that forms a sharp transverseedge projects into said aperture in such position relative to the pivot pin of the pawl that it bears against the fuse of the projectile in the course of engaging said body on the projectile and wedges itself against this fuse when the body of the grapple device is pulled out of the tube, and, secondly, means connected to said body of the grapple device whereby the grapple device may be pulled out of thetube from a position exterior of the tube of the gun.

The device operates automatically, independently of the operator, and requiresno setting. The operation lastsonly about fifteen seconds and this presents a tactical advantage in that it reduces to a minimum the interruption of the firing. The device is applicable to any standard fuse of brass or light metal.

Other features and advantages will be apparent from the ensuing description with reference to theaccompanying drawing in which;

Fig. l is a diagrammatic View in perspective, with a broken away portion, of a mortar in which the device according to the invention is shown in the course of the extractionof the projectile,

Fig. 2 is a longitudinal sectional view to a larger scale, oftherdevice, the grapple device being shown in the intermediate. position it' assumes in the course of its introduction into the, tube of the gun,

Fig 3, isan elevationaiview f h r pp e.

Fig. 4 is a view of the bottom end of the grapple de- 2,770,988 Patented Nov. 20,, 1 956 2. vice i. e. the end face thereof adjacent the projectile when this grapple device is in operation,

Fig. 5 is a longitudinal 'sectional'view of this grapple device at the moment when its pawls encounter the fuse of the projectile,

Fig. 6is a similar sectional view of this grapple device in the position it assumes when ready for the extraction of the projectile, and

Figs. 7 and 8' are two diagrams, to a larger scale, showing respectively the behaviour of a pawl when pulling out the grapple device and the behaviour of the elastic device acting on the pawls when only one pawl is. depressed.

In the illustrated embodiment the device is adapted to extract a shell or like projectile from the tubel of a gun or a mortar, for example the mortar represented in Fig. l which rests on a rear support plate 2 anchored in the ground and on a front stand 3. This projectile has a front ogive 5 at the end of which is screwed a fuse6.

The device according to the invention comprises in combination: a grapple device A adapted to be intro: duced in the tube 1 through the open end 7 of the latter so as to engage the fuse 6, a strong flexible cord B, of hemp for example, adapted to lower the grapple device A in the tube 1 and subsequently draw it out with the projectile, and a ring C adapted to be placed over the end 7 of the tube 1 for guiding the cord B.

The grapple device A comprises a cylindrical body 8 the outer diameter of which is equal, except for a very slight clearance, to the inside diameter d of the tube 1 of the mortar. This body 8 is preferably a light alloy casting and is provided on its upper face with an eyelet 9. A through passage or aperture is provided in this body along the axis thereof. This aperture is composed of, starting from the flat base 10 at the end of the grapple device remote from the eyelet 9, an ogival portion adapted to receive and fit over the ogive 5 of the projectile, thereafter a cylindrical portion 12 having a diameter greater than the overall diameter of the fuse 6, thereafter an end portion 13 having a smaller diameter and forming with the portion 12 a shoulder 14.

In thebody 8 are provided a number of longitudinally and radially extending slots 15. In the embodiment shown in Figs. 2 to 4, three slots are provided and, are. arranged about the axis of the grapple device at intervals. In the Figs. 5, 6 and 8 it has been supposed, for the sake of clarity of the drawing, that there are four slots diametrically opposed in pairs. Each slot 15 constitutes a through hole beginning at the outer cylindrical surface of the body 8 and ending at the

portions

11 and 12 of the axial aperture provided in this body. This slotv 15 includes on its upper face a shoulder 16 directed towards the exterior of the body 8. In each slot a gripping pawl a is pivotally mounted on a pivot pin 17 that is disposed perpendicular to the longitudinal axis of the grapple device A. Each pawl, which is of treated hard steel or other like material, comprises

essentiallyttwo branches

18 and 19 arranged in the form of an L. The branch 18, which extends radially towards the longitudinal axis of the grapple device, is terminated by a sharp transverse edge 20, perpendicular to the longitudinal axis XX of the body 8 (see in particular Fig. 7'). The branch 19, extends in a direction substantially parallel to the axis XX. On the side of the branch 19 facing away from the axis XX of the body 8 there is provided a knurled portion or ribs 21. On each pawl a is provided a heel 22 that lies substantiallyin the extension of the branch 19 but on the opposite of the pin 17 to the; latter. This heel is adapted to cooperate with the shoulder 16 of the corresponding slot 15.

All the pawlsa are urged to pivot about their respective pins 17 in the direction'ofarrow 7 (Figs. 2, 5, '7) by a ring 23 mounted to slide in the axial direction in the portion 12 of the aperture in the body 8. This ring is loaded downwards by a spring 24 that bears against the shoulder 14 of the body 8.: a j

Normally, under the action of the spring 24, the pawls a are held in the extreme position shown in Fig; 2 so that the heels 22 of the pawls abut against the shoulders 16 of the slots. The shapes of the pawls and the position of the shoulders 16 are so arranged that in this position the edges 20 of the pawls lie slightly to one side of the plane YY, perpendicular to the axis XX and passing through the geometric aXis of the pins 17, i. e. on the side of the plane YY towards the eyelet 9.

The collar C (Figs. 1 and 2) comprises a recess 25 by means of which it may be fitted on the end 7 of the tube 1 of the mortar. The inner cylindrical surface 26 of this collar has a diameter at least equal to the inside diameter of the tube 1 so that this collar does not hinder the easy extraction of the projectile 4 from the tube. This collar carries two parallel arms 27 which are outwardly inclined with respect to the tube 1 and form a fork in which is adapted to rotate, about a pin 28, a grooved pulley 29. i

To extract the projectile 4 provided with a fuse 5 from the tube 1, the following procedure is necessary:

One end of the cord B is attached to a fixed point outside the tube 1, for example to the point 30 on the stand 3 (Fig. 1). This cord is then passed through the eyelet 9 of the grapple device A. The latter is then slipped into the end of the tube 1, and the cord B forms a loop. The portion of the cord B attached to the fixed point 30 bears against the collar C at 31. The other portion of the cord passes over the pulley 28 and is held by one of the firing crew situated behind the tube. This person, by gradually playing out the cord, controls the descent of the grapple device A into the tube 1 under the effect of gravity. The grapple device A is guided by the tube 1.

At at certain moment before the inner wall 11 of the grapple device encounters the ogive 5 of the projectile, the sharp edges 20 of the pawls a encounter the fuse 6 (Fig. 5). There results a sudden stop in the descent of the pawls edges 20 while the body 8 of the grapple device continues to descend until it assume the position shown in Fig. 6 in which the surface 11 of the grapple device abuts against the ogive 5. In the course of the displacement of the body 8 from the position shown in Fig. 5 to that shown Fig. 6, the edges 20 of the pawls a are held in position (except for a small displacement mentioned hereinafter), whereas the pivot pins 17 continue to move in a direction parallel to the axis of the tube 1, i. e. in the direction of arrow f (Figs. 5, 7) and the branches 18 urge the ring 23 upwards thereby compressing the spring 24, and the heels 22 separate from the abutments 16 (compare the positions shown in Figs. 5 and 6).

Finally, when the grapple device A is seated on the projectile (Fig. 6), the branches 18 of the pawls a have assumed an oblique position as represented, to a larger scale, in Fig. 7, and the edges 20 are then situated in the transverse plane 22 perpendicular to the axis XX and situated at a certain distance x above the transverse plane YY passing through the axes of the pivot pins 17.

It will be observed that between the positions shown in Figs. 5 and 6 the edges 20 pass from the plane YY to the plane ZZ and the radial distance 1 between the edge 20 and the axis of the corresponding pivot pin 17 very slightly decreases owing to the inclination assumed by the branch 18. The edges 20 describes, then, a portion of a cylinder \"V (Fig. 7). But this decrease in the length l is compensated by the increase in the diameter of the fuse 6; for the edge 20 slides from the point m (Fig. 5) where it encounters the fuse to a point It (Figs. 6 and 7).

Hence, to extract the projectile, it suffices to pull in the direction of arrow f (Fig. 1) on the free portion of the cord B. The body 8 of the grapple device A and the pivot pins 17 are moved in the direction of arrow f (Fig. 7), whereas the edges 20, being in contact with the fuse 6 at point 11 and being anchored or wedged on the latter, cannot move. The pawls a tend therefore to pivot in the opposite direction to arrow f (Fig. 7) and the edges 20, which are constrained to describe the portion nV of the cylinder V V wedge or anchor still more in the fuse 6. When the pawls a cease to pivot about the pivot pins 17 the projectile 4 is carried upwards by the grapple device A and is very easily extracted from the tube 1.

When the projectile has been extracted the fuse is released from the grapple device A by merely depressing the portions 21 on the branches 19 of at least two pawls a.

It will be observed that an accidental depression (Fig. 8) of one pawl a would not release the fuse; for the ring 23 would then assume an oblique position in the aperture 24 and would wedge therein in such position as to hold the other two pawls a in their active or fuse gripping position.

Although a specific embodiment of the invention has been described hereinbefore, it is to be understood that changes and modifications may be made therein without departing from the spirit and scope of the invention as hereinafter claimed.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Device for extracting after a misfire a projectile and its fuse from the tube of a muzzle-loaded mortar or other arm, comprising in combination: a cylindrical body having a forward plane transverse face and a transverse rear 'face; said body having a central cavity opening at least on said forward face, the walls of said cavity being adapted to surround said fuse without contacting it, even when said walls contact said projectile; said body having a plurality of radial slots between said cavity and the lateral outer wall thereof; the walls of each of said slots forming an outward shoulder; a gripping pawl in each slot and pivotable around an axis within said slot; the axis of all said pawls being located in a single transverse plane parallel to said forward face; each said pawl having substantially the shape of a T, the first branch of which is radially directed towards, and projects into, said central cavity, the end of said first branch being formed into a sharp edge parallel to said transverse plane; the second branch of each said T-shaped pawls being substantially parallel to the lateral outer wall of said body, and being accessible from outside aid body through said slot; a heel extension on each said second branch adapted to cooperate with said outward shoulder; elastic means co operating with said pawls and adapted to force said heels against said outward shoulders when the device is idle; said sharp edges of said pawls being located, when the device is idle, on a transverse plane located slightly rearwards toward the rear face of the body relative to the transverse plane of the axis of said pawls; whereby said sharp edges abut the fuse when said cavity receives said fuse and said projectile, and grippingly Wedge against said fuse when said body is removed by traction from the tube. v

2. Device as claimed in claim 1, in which the walls of said central cavity comprise an abutting shoulder; said elastic means comprising a spring located in said central cavity and abutting at one end said shoulder; and further comprising a ring freely movable in said central cavity and disposed between the other end of said spring and the radial directed first branches of said pawls.

3. Device as claimed in claim 1, in which said body includes an eyelet rigidly connected with the rear face of said body; and comprising further a crown to fit over the end ofthe muzzle, a fork attached to said crown and inclined outwardly from said tube, a pulley pivotally mounted in said fork, a traction cord passing over said pulley and through said eyelet; whereby the projectile can be safely extracted from 'the arm by a traction exerted on 1,657,368 Carter Jan. 24, 1928 said cord from a position rearward of the muzzle. 1,738,789 Newkirk Dec. 10, 1929 1,749,869 Baumbach Mar. 11, 1930 References Cited in the file of this patent 2,405,018 I Crowley J ly 30, 1946 UNITED STATES PATENTS 5 2,410,262 Breaux Oct. 29, 1946 1,402,677 Smith Ian. 3 1922 2,478,019 SOnnt-ag g- 1949 1,553,991 Davison et a1. Sept. 15, 1925 FOREIGN PATENTS 1,563,600 Walton Dec. 1, 1925 226,580 Germany Oct. 4, 1910