US1639665A - Depth charge and like submarine explosive body - Google Patents

Description

Aug.` 23, 1927.

H B PRATT DEPTH CHARGE AND LIKE SUBMARINE EXPLOSIVE BODY Filed` oct,

g H. B. PRATT DEPTH CHARGE ANDLIKE SUBMARINE EXPLOSIVE BODY FiledOct. 1. 1925 2 Sheets-Sheet 2 Patented Aug. `23, 1927.

Unirse STATES HARTLEY IBLYTH PRATT, OF BARROW-IN-FURNESS, ENGLAND, ASSIGNOR TO VICK- ERS LIMITED, OF WESTMINSTER,

ENGLAND, A BRITISH COMPANY.

DEPTH CHARGE AND LIKE SUBMARINE EXPLOSIVE BODY.

Application led October 1, 1925, Serial No. 59,808, and in Great Britain October 3,1924.

This invention relates to depth charges and like submarine explosive bodies. More particularly the invention relates to socalled depth charges or like bodies which are adapted to fire automatically on reaching a predetermined depth.

It has been proposed to lire such depth charges at a predetermined depth by means of hydrostatically operated mechanism and one form of such mechanism involves the use of a timing device comprising a chamber into which water can flow at varying selected rates, the arrangement-being such that the time taken to fill the chamber to the required extent for o erating the hydrostat and so firing the dept charge is equal to or substantially equal to the time taken for the body to sink freely to a specified depth,

and the chief object of the present invention is to provide a submarine explosive body the firing mechanism of which is directly operated by the hydrostatic pressure and independently of the speed or time taken for the depth charge to sink to the desired depth.

According to the present invention the regulation of the firing depth is effected by varying the volume into which a quantity of trapped air is compressed. To this end a quantity of air may be trapped between relatively movable parts, one or both said parts being acted upon by the hydrostatic pressure and the arrangement being such that automatic firing takes place when the water pressure brings the relatively movable parts into correct relative firing position. The depth at which ring is adapted to take lace may be controlled as desired by vary-- 111g the capacity of an air space or spaces so as to increase or diminish the volume of air initially trapped between the aforesaid relatively movable parts.l Consequently the external Water pressure (and hence the depth of sinking), which is required to re the explosive body willbe that which is necessary to'compress any particular volume of trapped air to the extent which is necessary to allow the relatively' movable parts to reach the firing position.

4 In the case of a depth charge, the pistol and primer may be located within la tubular casing, and air may be trapped in said tubular casing `between the piston and the primer. The primer itself may be movable under the influence of the hydrostatic pressure so that it acts as a piston which will compress the air trapped in the said tubular casing. The primer'is normally located some distance away from the pistol, and, after launching of the depth charge, and under the influence of the hydrostatic pressure the primer will move forward along the tubular casing and compress the trapped air. When sufficient hydrostatic pressure is available to move the primer into correct relative firing position with regard to the pistol, the pistol is automatically actuated and explodes the depth charge. Additional air spaces, suitably controlled by a valve or the like may also be provided one or more of said air spaces being adapted to tbe placed in communication with the air space between the pistol and primer units so as to vary the ring depth.

In order that the said invention may be clearly understood and readily carried into effect the same will now be described more fully with reference to the accompanying drawing, in which Figure l is a longitudinal section` of a depth charge constructed accordingto one `embodiment of the present invention, the

parts being shown in the position which they occupy prior to launching of the depth charge.

Figure 2 is a detail view of part of the depth charge showing the primer and pis-V tol in the tiring position.

Figure 8 is a section on the line X-X of Figure 1, and

Figure 4 is a View looking down on the head of the piston and showing the depth indicating dial. I

Figure 5 is a view corresponding to Flgure 1 showing a modified construction of depth charge, and Figure 6 is a detail view showing the depth indicating dial.

Referring to the embodiment of the invention shown at Figures 1 toil, A is a guide tube located centrally of a main casing or charge case B, which contains the bursting charge C, the guide tube A beingwelded at one end a directly to the charge case B, its other 'end being welded to a flanged part a2 ofthe charge case. The primer D1'1s located within a casing D (hereinafter termed the primer case) whlch is of cy lindrical formation and s lidably mounted within the guide tube A so as toact as a piston or plunger. Normally the primer case F through passages Z,

D is located at one extreme end of the guide tube Al (as shown at Figure 1,), and, to hold it in this position up to launching of the depth charge, the primer case D may be provided with a projecting part d which extends through a bun or closure plate d1" positioned Within the gulde tube A, the said bung or? closure plate Z1-having openings Z2 for admitting water to the guide tube A. The primer case D is normally held in the position shown at-Figure 1 by means of a safety pin d3 which'engages a recess in the said projecting part al said pin d3 being removed before the depth char e is launched. An airtight joint between t e primer case D and' the guide tube A may be effected in any desired manner, for example, by providing a ring of rubber or other flexible material al* between the primer case D and the guide tube A, said rubber ring d4 being adapted to allow the' primer case D to move relatively to the guide tube A while atthe same time preserving an air and Water-ti ht joint. E is the pistol which is secure by bolts e to the flange aF so as to form an air-tight joint, and is located at the opposite end of the guide tube A. e1 is a detonator which is mounted at the end'of a tube e3 (hereinafter termed the detonator carrier)l which projects into the guide tube A. The striker e4 is located within the detonator carrier e3 and said striker is provided with a flange e5, between which and a-plug e6 a firing spring e7 is located, The detonator carrier e3 and the striker e4 are capable of relative sliding movement but `such move- 'ment is normally vprevented by means of suitable releasing devices, such for example as a so-called ball release, the laterally displaceable balls e8 being located within a slot in the detonator carrier e3 and projecting into a groove in the striker e4. Surrounding the striker e4 and the detonator carrier e8 is a casing e9 (hereinafter termed the striker casing), the detonator carrier e3 being provided with a flange at its inner end which flange is normally held against a shoulder 01 on the striker casing e by the striker spring e7.' Positioned around the striker casing e9 in a hollow box-like part F (hereinafter termed the airy chamber) which is divided into compartments f1, f1 of different sizes by means of division plates f, f.' Air spaces are therefore provided and one or more of said spaces can be placed as desired in communication with the main air space Gr in the guide tube A by'suitable means. For example a rotatable plate valve H may be provided which is formed with openings k which can be manipulated as desired to place one' or more of the compartments f1, f1 in' the air chamber in communication, with the air space G in the guide tube The plate valve HA is positioned around the striker casing e"v f3 of the air chamber F by means of a spring I located between the plate valve H and a nut z' on the striker casing e9. The part of the striker casing e9 which projects beyond the base of the depth charge may be provided with a pointer @1 and, on the contiguous part of the air chamber a scale or a series of calibrations f4 (Figure 4) may be provided so as to indicate the adjusted depth at which firing will take place. For example, when the air chamber F is not in use the air trapped in the space G between the primer case D and the plate valve H may be adapted to fire the pistol at a depth of 300 feet. Where for example and as shown at Figure 3 four* compartments are provided in the air chamber P the arrangement may be such that when one of said compartments f1 is added to the clearance volume G in the guide tube A the depth charge will fire at 200 feet; lwhen another compartment is added the depth chargeV will fire at 150 feet; when a third compartment is added the depth charge will fire at feet and when the fourth compartment is added the depth chargewill fire at 50 feet. Regulation of the volume of trapped air, or in other words the number of compartments added to the clearance volume in the guide tube A, I

is effected by rotatino the plate valve H by` means of a key applied to the part e on the end of the striker casing e. The striker casing e" is provided with splines e11 which engage the plate valve H -so as to cause the latter to turn'with the striker casing e9; When the pointer elo on the striker casing e9 is brought opposite a calibration corresponding to a particular depth the required openings z, in the plate valve H will register with the requisite passage or passages f2, f2 communicating with an appropriate compartment f1 or compartments f1, f1 in the air chamber F. The rotaton'of the striker casing e9 and consequently the plate valve H may be controlled by means of a detent e12 provided either `at the base of the air chamber or (as shown) on the pointer el carried by the striker casing e9 the detent e12 being hld within a seat either on the air chamber or on the pointer by the pressure exerted by the spring I located between the plate valve H and the flange lon the striker casing.` By a forcible effort exerted by means of the aforesaid key the detent e12 is-lifted out of its seat and the striker casing egfis turned and the detent will thereafter' slip into the next seat corresponding to any particular calibration.

The primer case D, as aforesaid, is normally held at the top of the depth charge by means of a safety pin d3. When this safety pin is removed and the depth charge launched, Water passes through the openings dz in the bung or cover plate d* and zoo i fire after the tiring pressure.

the hydrostatic pressure acts on the outer end of the primer case D and also on the aforesaid rolling rubber ring d2. The primer case D is therefore pushed up the guide tube A and compresses the air between the inner end of the saine and the plate valve H or the air compartments in the air chambers F if any of' them have been opened. Leakage of air outwards or water inwards is etfectually prevented by the rolling rubber ring d4 and accordingly the external water pressure and the internal air pressure will be substantially the same, the water pressure being slightly greater so as to overcome the sliding friction of the rolling rubber ring (Z4. There is therefore no tendency for air to leak outwards and with the slight difference in pressure on each side of the rubber ring Z" the latter effeetually prevents water leakage inwards. The pistol E as aforesaid, is adapted to hydrostatic pressure has pushed the primer case D up to the top of the guide tube A into a position where the detonator e1 projects into a recessed part Z1 in the primer case D. When the parts are in this position the detonator carrier e3 is pushed along the striker cA1 and compresses the striker spring e1 the compressing action being continued until the balls e13 of the ball' release pass beyond the 'shoulder in the striker casing whereupon they move laterally outwards and disconnect the striker from the detonator carrier. The reaction of the striker spring then forces the striker violently in contact with the detonator exploding the same and detonating the primer, and consequently exploding the main bursting charge.

In the modified arrangement shown at Figure 5 the same reference letters have been employed to designate the same or corresponding parts of the depth charge. In this embodiment of the invention, however, two air chambers K1 and K2 only are rovided in the pistol. adapted to be placed into communication with the space G by a port le and the chamber K1 is adapted-to be placed into communication with the space G by means of a tube k1 extending through the chamber K2, the port k and the tube k1 being controlled as before by a rotatable plate valve H having ports h, l1. formed therein. The capacity of these three air chambers G, K1 and K2 may be such as to provide for three depth settings. namely 60, 120 and 180 feet. For the 1.80 feet setting bot-h the chambers K1 and K2 are closed of so that the clearance volume G in the guide tube A determines the For the 120 feet the volume K2 is added and for 60 feet the volumes K1 and K2 are added.

If desired additional air chambers can also be provided if more depth settings are The chamber I 2 isr required. The adjusting mechanism for rotating the plate valve H comprises a nut H1 secured to the striker c4 the plate valve H being integral with or rigidly connected to the lower end of the striker e1 so that it rotates therewith. Splines I", F are provided between the rotatable nut and the casing Within which the striker is adapted to rotate. The nut H preferably carries a pointer H2 which serves the combined function of rotating the nut H and at the same time indicating the particular calibration on the dial H2 to which the pointer has been adjusted.

To renderthe pistol safe when the pointer is set to the calibration Safe the part L is provided with a serrated flange L1 and corresponding seirations M1, M1 are cut in the. body portion M. When the setting at Safe the serrations L1 are located opposite the serrations M1 thus preventing movement of the part L and consequently preventing .operation of the pistol release. lVlien, however, the pointer H2 is moved over to indicate a depth setting the serra-- tions L1 allow the part L to move through the part M1.

Instead of providing av fixed pistol unit and a moving primer unit the primer can be fixed and the pistol unit can be adapted to move, or, alternatively both the pistol and primer units may be adapted to move inwards simultaneously so as to effect the eX- plosion of the mine vin the manner previously described. f

Vhat I claim and desire to secure by Letters Patent of the United States is 1. A depth charge or like submarine body comprising members movable relatively to one another under the influence of the hydrostatic pressure, means for automatically exploding the body when said members come into contact with one another and means for varying the volume of air compressed by said members in moving into contact with one another so as to vary the depth at which automatic firing takes place.

2. A depth charge or like submarine explosive body comprising members which are normally situated apart and between which a predetermined volume of air is trapped, said members being adapted to move towards one another under the influence of the hydrostatic pressure, means for trapping a predetermined volume of' air between said relatively movable members and means for automatically firin the body when the hydrostatic pressure as compressed the predetermined volume of trapped air to the extent which is'necessary vto bring said relatively movable members into correct relative tiring position.

3. A depth charge in which the automatic tiring gear comprises a plurality o f units which are movable into contact with one another under the iniuence of the hydrostatic pressure and means for varying the volume of air which is compressed by said units in moving into contact with one another so as to vary the depth at Which automatic firing takes place.

4. A depth charge or like submarine explosive body comprising two units which are movable towards one another under the influence of the hydrostatic pressure, means for trapping a predetermined volume of air between said relatively movable units and means for automatically ring the body when the hydrostatic pressure has com-v pressed the predetermined volume of trapped air to the extent which is necessary to bring the said relatively movable parts into corvrect relative ring position.

5. A depth charge or like submarine explosive body comprising a tubular casing, a pistol and a primer unit located within said tubular casing, said pistol and primer units vbeing separated by an air space, means for trapping apredetermined volume of air in said air space, said primer unit being movable under the influence' of the hydrostatic pressure so as to compress the air trapped 1n said air space for the purpose specified.

plosive. body comprising a Atubular casing,

a pistol and a primer unit located within said tubular casing, said pistol and primer units being separated by an air space, means for trapping a predetermined volume of air in said air space, said pistol unit being movable under the influence of the hydrostatic pressure so as to compress the airv said air space for the purpose being separated by an air space withinA which a predetermined volume of air is trapped, both said` units 'being movable under the influence of the hydrostatic pressure -so as to compress the air trapped-in said air space for the purpose specified.

8. A depth charge or like submarine explosive body comprising a tubular casing, pistol and primer units located Within said tubular casing, with an air space between said pistol and primer units, and means for placing additional air spacesin communication with the air space between said pistol and primer units for 'the purpose specified,

HARTLEY BLYTI-I` PRATT.

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