Aerial mortar.

Application filed August 30,1916. Serial No. 117,578.

To dll whom it may concern:

Be it known that I, Lester P. Barlow, a citizen of the United States, residing in the city and county of Philadelphia, State 5 of Pennsylvania, have invented certain new and useful Improvements in Aerial Mortars, of which the. following is a specification.

My invention relates to what I may term aerial mortars, that is to say a construction 10 which comprises a barrel, breech and firing mechanism, and a bomb or projectile contained in or carried by the barrel, and adapted to be expelled therefrom, the whole construction being adapted to be dropped from 15 an aeroplane or other flying machine (or with modifications, launched from a gun). The. mortar as a whole is intended to fall vertically, or at a desired angle, and embed itself in. the earth pr other object struck.

Arrangements are provided such that the mortar as an entirety is brought to rest after entering the earth or object struck a comparatively short distance, after which the bomb or torpedo (or projectile) is ex25 pelled upwardly from the outer shell, or barrel,, the object being to provide for the explosion of the bomb above the objecft struck and not, as particularly in the case of striking the earth, within the object 30 struck, with the necessary result of a confined explosion. Accordingly arrangements must be provided for causing the explosion of the bursting charge within the bomb when the latter has risen to a desired dis35 tance above the surface of the earth or object struck.

A device of this character is described in my application Serial No. 104,209 aerial hand grenade, filed June 17, 1916. In the 40 device described therein a delay charge, or fuse, is exploded when the striking nose of the device hits the earth, or object struck, this delay charge causing the explosion of an expelling charge after the downward mo45 tion of the grenade' has been arrested. Simultaneously with the upward expulsion of the bomb from the outer shell a second delay charge or fuse is exploded, which in turn explodes the bomb after the latter has 50 risen a desired distance above the object struck.

My present invention is in some respects a modification and in some an improvement upon the structure referred to. According to ⁵⁵ my present invention the explosion of the bursting charge in the bomb, after the latter has been driven upwardly, is not caused by a delay fuse but by mechanical means comprising a flexible connection which is anchored at its lower end in the embedded 60 portion of the mortar and connected at its upper end to a relatively movable member in the bomb proper. When this connection has been extended to its full length the upward movement of the mechanism in the 65 bomb to which the connection is secured is arrested, causing the concussion of a cap which serves to explode the bursting charge in the. bomb. By this means the explosion is positively caused to take place at a defi- 70 nitely predetermined distance above the earth.

My present invention is also concerned with other improvements of construction and combination of parts as will be herein- 75 alter more fully set forth and claimed in the accompanying claims.

In order that a clearer understanding of my invention may be had attention is hereby directed to the accompanying drawings 80 forming a part of this application and illustrating one construction whereby the desired objects may be. accomplished.

Referring to the drawings Figure 1 represents, in side elevation an aerial mortar em- 85 bodying a form of my invention, Fig; 2 represents an enlarged central, vertical, sectional elevation through the mortar of Fig. 1, Fig. 3 represents a partial enlarged sectional detail view of the lower portion of 90 the barrel or gun-shell of the mortar with the breech block secured therein and the bomb mounted in place above the same, Fig. 4 is a view similar to that of Fig. 2 indicating, however, the position of the parts 95 when the mortar has been dropped and plunged into the earth and when the bomb expelling charge has shot the bomb almost clear of the gun-shell, and Figs. 5, 6 and 7 are cross-sectional views shown respectively 100 on lines 5—5, 6—6 and 7—7 of Fig, 3.

Referring to the drawings, the numeral 1 designates a shell or casing which I term the gun-shell or barrel, within which is contained the bomb or torpedo 2. The gun- 105 shell is preferably a cylinder of sheet-metal formed at its upper end with stabilizing wings or blades which I term the stabilizers 3 and which are preferably formed by stamping out longitudinal, segmental sec- 110

1,236,637 tions of the shell. At its lower or striking end the shell may be slotted or cut longitudinally so as to form what I term spreading flanges 4, any desired number of which may 6 be formed by slots 5 stamped out of the material of the walls of the shell. These flanges when spread by contact with the earth serve both to prevent too deep penetration and to anchor the shell, the position of these flanges 10 when the shell has come to rest in the earth being shown in Fig. 4.

Within the lower or forward end of the shell is inserted the block 6 which I term a “ breech block ” or “ gun 1 >reech mechanism ”. 15 preferably of the form indicated in Figs.

and 3. This breech block fills the interior of the lower end portion of the shell, is cylindrical and is secured permanently within the shell, preferably by being formed 20 with circumferential grooves 7 into which the walls of the shell are forced or crimped by being formed into the circumferential internal beads 8.

The breech block 6 is formed with re25 cessed portions of different diameters which will now be described. An enlarged chamber 9 is formed within the upper portion of the breech block and within this is contained the bomb expelling charge 10 of any pre30 ferred explosive. The bomb or torpedo 2 is mounted above this chamber? as shown. Below chamber 9 there is a cylindrical chamber 11 of less diameter than chamber 9 and having a screw-threaded bore in which is 35 mounted the externally screw-threaded recessed cylindrical member 12. The upper portion of member 12 extends into chamber 9, while the lower portion extends downwardly as far as does the chamber 11 in 46 which it is screw-threaded. Below chamber 11 there is provided a cylindrical recess 13 of enlarged diameter extending to the bottom of the lower tubular wall 14 of the breech block.

The lower portion of cylindrical member 12 is recessed, as is shown at 15, this recess extending into the base chamber 13 referred to and having a top circular wall 16. The penetrating nose piece 17 is mounted within 50 base chamber 13 and has a cylindrical head portion 18 slidably mounted within the chamber 15 of member 12. The nose piece 17 is preferably cylindrical for a portion of its length at the upper section thereof, as is 55 shown at 19, where it is slidably fitted, within the tubular wall 14 of breech block 6.. Nose piece 17 is preferably conical from this point downwardly and extends outwardly some distance from the lower end of shell 1. A «0 firing pin 20 is formed on the upper surface of the cylindrical portion 18 of the nose piece. .

The nose piece is normally retained in the position represented in Figs. 2 and 3 by the 65 cotter pin 21 which is adapted to extend through a tube 22 of copper or other relatively soft metal. This tube extends through alined bores which are drilled through the barrel 1, breech block 6, and the depending annular wall of member 12, and also the 70 head piece' of nose piece 17. That is to. say, when member 12 is screwed into position in the breech block, the opening referred to in member 12 is alined with the corresponding opening through the breech block and 75 the outer shell and the nose piece 17. is slipped into position with the opening through the head 18 thereof in alinement with the said bores, after which the tube 22 may be inserted through the alined openings 80 and cotter pin inserted^-through the tube. When the mortar is dropped from an aeroplane, or otherwise launched, the cotter pin 21 is first withdrawn. When now the nose piece 17 strikes the earth or other object 85 encountered, the soft copper tube 22 will be sheared through, driving the firing pin 20 into contact with the fuse-cap 23 to explode the cap.

Fuse-cap 23 is mounted in the lower wall 90 of the charge cup 24 which is of cylindrical form with external screw-threads and is screwed into an internally screw-threaded chamber 25 formed in member 12. Charge cup 24 has a chamber 26 formed in the 95 upper part of the same, this chamber being filled with the delay fuse 27 formed by . an explosive mixture, the period of explosion of which is calculable and relatively slow. An axial passage 28 connects fuse-cap 23 100 with the delay fuse 27.

The upper annular wall of charge cup 24 has two or more radial openings 29 extending through the same into the surrounding portion of chamber 25. The portion of 105 member 12 surrounding chamber 25 has a plurality of radial openings 30 extending therethrough connecting chamber. 25 with the surrounding portion of explosive chamber 9 of breech block 6. A circular washer 110 31 is preferably placed on top of the delay fuse 27 in chamber 26.

The result of the construction described is that when nose piece 17 strikes an object and is therefore driven upwardly H5 through chamber 13, firing pin 20 explodes fuse-cap 23 and the latter in turn explodes . the delay fuse 27. The explosion of the latter, however, does not take place for a moment, or until the downward movement of 120 the grenade as a whole through the earth has been stopped or appreciably checked. The products of explosion of fuse 27 pass radially through openings 29 .and openings 30 into the bomb expelling charge 10, ex- 125 ploding the latter and driving bomb 2 upwardly.

.Bomb 2 contains a closed magazine chamber 32 which is filled with a high explosive charge designed to shatter the bomb when 130

1,235,637 s

exploded. In the form of my invention illustrated, the chamber 32_s extends downwardly through the lower end of the bomb or torpedo 2 and is internally screw-thread5 ed at its lower portion, as is indicated at

33. A cylindrical member 34 having an externally screw-threaded periphery is screwed into the screw-threads 33 to securely hold the same in position at the lower 10 end of the bomb. Member 34 has an axial cylindrical chamber extending through the same, the upper portion of which is internally screw-threaded, as is shown at 35, while the lower portion of the recess has a 15 smooth bore and is of less diameter than the upper portion, as shown at 36. A detonator 37 carrying a charge of detonating material such as fulminate of mercury 38 has an annular screw-threaded wall 39 be20 low the charge 38, the tubular wall 39 being firmly screwed into the screw-threads 35 of the upper portion of the chamber in member 34. _ Member 34 carries a firing pin 40 which is integral with and extends axially 25 upward from a bridge piece 41 which extends across the central opening through member 34, the ends of the bridge piece being, secured in the side walls of member 34.

A member 42 is formed with a circular 30 base portion 43 and a tubular upwardly extending portion 44. The circular flange or base 43 is adapted to extend beneath the lower end of bomb 2 and member 34 therein and to be seated, in the position of the 35 parts shown in Figs. 2 and 3, on a shoulder 45 formed at the upper portion of chamber 9 .in breech block 6. The tubular upwardly extending portion 44 is slidably mounted in the cylindrical chamber 36 of 30 member 34. The walls of cylindrical member 44 are longitudinally slotted at diametrically opposite points, as in indicated at 46 in Fig. 6, for the passage therethrough of bridge piece 41, so that member 42 with 35 its tubular extension 44 may move up and down relatively to the member 34 and bridge piece 41 secured thereto.

The upper portion of tubular member 44 is internally screw-threaded to receive a >0 charge cup 47 containing a fuse-cap 48, the upper face of charge cup 47 being provided with openings 49 extending from the fusecap 48 into .the cylindrical space 50 below the detonating charge 38 and inclosed by >5 the annular wall 39 of the detonator.

The bomb or torpedo 2 is normally secured in position on the breech block 6 by a suitable detachable means such as a few turns of screw-thread 51 formed on the inner 0 periphery of the tubular breech block adjacent the upper end thereof. Preferably the bomb or torpedo is formed with a bottom portion 52 of reduced diameter which is mounted within the upper end of the 5 breech block and secured thereto by the screw-thread 51 as shown, the peripheral shoulder 53 thus formed on the bomb resting on the upper surface of the breech block, while the bottom surface of the bomb rests on the base 43 of member 42, which in turn 70 rests on the shoulder 45 of the breech block.

A flexible cord or wire cable is connected at its respective ends to member 12 and member 42. For this purpose one end of cable 54 may be extended through a per- 75 foration in the top of member 12 into a recess 55 therein, in which it is secured, recess 55 being closed by a washer 56 at its lower surface. Cable 54 may then be coiled about the upper portion of member 12 within 80 chamber 9. The upper end of the cable may conveniently be secured to member 42 by extending it through a perforation in the bottom of member 42, the end of the cable being upset, or otherwise secured, as shown 85 at 57 in the lower end of the central chamber of tubular member 44.

The operation of the device will now be apparent. When the mortar strikes the earth, the engagement of member 42 with 90 shoulder 45 prevents a premature contact between firing pin 40 and fuse cap 48. When, thereafter, the expelling charge 10 in chamber 9 has been exploded, as stated, the screw-threads 51 are stripped off and the 95 bomb, together with member 42, driven upwardly, as is shown in Fig. 4, until it has been expelled from tube 1 a distance of say eight or ten feet when cable 54 will be taut. During this interval member 42 will be 100 pressed firmly into contact with bomb 2 by the presssure of the explosion in chamber 9. When cable 54 has become taut, however, the upward movement of member 42 will be arrested, while the momentum of bomb 2 105 will continue to carry the same up. Therefore bridge piece 41 which is secured to member 34 and the bomb 2 will continue to rise with the result that firing pin 40 contacts with fuse-cap 48 exploding the same. 110 The explosion of fuse-cap 48 explodes the detonating charge 38 which explodes the high explosi ve in magazine 32 in the bomb.

While the construction described well illustrates my invention, it should be under- 115 stood that my invention is not strictly limited to the exact construction described. Thus in regard to the movements of the firing pin 40 and the detonator 37, it is only essential that a relative movement should be 120 caused to take place between these parts when the proper moment for the explosion of the bomb has arrived, this relative movement being such as to cause contact between them to explode the detonator. It is not 125 essential that the detonator should be permanently mounted within the magazine chamber of the bomb. In my copending application Serial No. 117,579, bombs or torpedoes, filed on August 30, 1916, I have 130 •4

1,235,637 illustrated an arrangement by which the detonator is normally mounted outside the magazine chamber of the bomb and is brought into the magazine chamber and into 5 contact with the firing pin only when cable 54 has become taut.

It will be noted that one of the advantages of my present construction consists in the continuous passageway extending from 10 chamber 9 of the breech block to the forward end of the breech block, before member 12 and nose piece 17 have been mounted in place. This continuous passageway permits chamber 9 to be filled with the explo15 sive charge 10 from the forward end of the structure. The preferred arrangement of fuse-cup 24 should also be noted, whereby the products of the explosion of the delay charge 27 pass radially through openings 29 20 and 30 into the surrounding explosive mixture in chamber 9.

In the claims, the member containing the burstin'g charge, which is adapted to be expelled from the outer barrel of the aerial 25 mortar, will be referred to as a “bomb.”