US3027836A - Underwater explosive device - Google Patents

Description

April 3, 1962 J. T. HAMRICK 3,027,836

UNDERWATER EXPLOSIVE DEVICE Filed March 28, 1960 3 Sheets-Sheet l fu y/5272271" Jase A ZHamvwti April 3, 1962 J. T. HAMRICK UNDERWATER EXPLOSIVE DEVICE 3 Sheets-Sheet 2 Filed March 28, 1960 3 h R Q S 3 a L N Q Q i \Q J hi LI & Km a w. NM

frzz Enfur Jase i THamrzck Eff 5 April 1962 J. T. HAMRICK 3,027,836

UNDERWATER EXPLOSIVE DEVICE Filed March 28, 1960 3 Sheets-Sheet 3 Jasef Z Hamri c a M aazzsst HQ p t d Apr, 3, 1962 3,627,836 UNDERWATER EXPLUSIVE DEVICE Joseph T. Hamrick, Cleveland, Ohio, assignor to Thompson Ramo Wooldridge Inc., Cleveland, Ghio, a corporation of Ohio Filed Mar. 28, 196i Ser. No. 18,057 3 Claims. (Cl. 102--7) The present invention relates broadly to the art of demolition, and is more particularly concerned with a new and improved underwater explosive device mounting thereon bumper means to prevent detonation of the device in close contact with foreign objects.

It is known in the art that detonatable devices designed for destructive underwater applications can be actuated to explode at various predetermined depths under control of timer means or hydrostatic pressures. Pressure actuated explosive devices have the advantages of structural simplicity and reliability, although whether the detonatable device be timer actuated or pressure actuated, there remains the problem of explosion should the device directly contact a foreign object located in the descent path of the explosive device. The foreign underwater body may be a submarine hull or some other blunt object moving into or stationarily located in the path of descent of the detonatable device, and not sensed prior to release of the explosive package. The foreign underwater body could in fact be a friendly submarine hull.

It is accordingly an important aim of the present invention to provide an explosive device for underwater applications equipped with guard means rendering intimate contact detonations generally remote possibilities.

Another object of this invention lies in the provision of an explosive package featuring extreme accuracy of operation and relative simplicity of fabrication and assembly.

Still another object of the invention is to provide a device for performance of underwater demolition tasks, comprising a body member carrying an explosive charge and mounting a plurality of extensible means for isolating the explosive charge from bodily contact with foreign submerged objects,

A further object of this invetnion lies in the provision of an explosive device particularly adapted for destructive underwater use, and which comprises a housing providing communicating arming and firing chambers, a charge container normally attached to the housing, a firing mechanism in the firing chamber movable toward the arming chamber under action of water pressures, an arming mechanism in the arming chamber passaged to receive the firing mechanism for detonation of the charge in the container, and a plurality of extensible arms normally carried by the housing in a collapsed condition thereon and swingable outwardly in protection of the charge container during movement of the arming mechanism in the arming chamber under influence of water pressures.

Other objects and advantages of the invention will become more apparent during the course of the following description, particularly when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals designate like parts throughout the same:

FIGURE 1 is a perspective view of an underwater explosive device constructed in accordance with the principles of this invention, and with the guard means thereon in an extended position;

FIGURE 2 is a side elevational view of the explosive device, with parts thereof taken in section to more fully illustrate the arming mechanism and extensible leg structure;

FIGURES 3, 4 and 5 are fragmentary detail sectional views of various portions of the extensible legs to show the telescoping structure provided;

FIGURE 6 is a fragmentary detail sectional view of the arming chamber to show one arrangement for obtaining release of wire restraining means on the extensible legs;

FIGURE 7 is a side elevational view of the underwater explosive device in its collapsed condition and prior to being dropped overboard for demolition applications;

FIGURES 8, 9 and 10 are fragmentary detail sectional views of the leg mounting arrangement provided and illustrative of one form of stop means to restrain the legs in a particular angular relation with respect to the axis of the explosive device; and

FIGURE 11 is a fragmentary plan view of the ring means and hinge arrangement to support the extensible legs.

Referring now to the drawings, and first to FIGURE 1 thereof, an underwater explosive device embodying the novel concepts of this invention may be seen to be designated generally by the legend A. The device comprises a main body portion 20 which may be formed as an integral cast structure to provide a housing 21 for the operating mechanisms and an annular guide head 22 which cooperates with the housing 21 to mount a plurality of stabilizing fins 23. Connected to the housing 21 is a charge container 24 for housing a supply of TNT or the like and threadably received on the container 24 is a cap member 25, providing access to the interior of the charge container 24 and further controlling the extent of outward swinging movement of guard or bumper means generally designated by the numeral 26.

In the form of the invention shown in FIGURE 1, a total of fourteen identical bumper arms 26 are provided which extend a total length of approximately 22 inches from the supporting charge container 24. As is seen in FIGURE 1, the arms 26 bear various angular relationships with respect to the axis of the housing 20, and as will be more specifically noted hereinafter, certain arms 26a are disposed at right angles to the housing 20, other arms 26b are located at an angle of approximately 45 with the housing 20, and other arms 26c when extended form and angle of about with the housing 20. The arms 26a-c accordingly form therebetween a 60 mesne angle, and when an arm length of 22 inches is selected, the altitude to the base of an enclosed triangle which has the bumper arms as two sides is slightly more than eighteen inches. In this manner, the major number of blunt foreign objects which the explosive device A may encounter cannot be straddled by the bumper arms 26, and intimate contact of the charge in the container 24 with the foreign object is effectively prevented.

As appears more fully in FIGURES 2 and 7 to 11, the mounting means for the bumper or guard arms 26 may take the form of a ring member 27 welded or otherwise secured to the outer diameter of the charge container 24 intermediate its opposite ends. Although the bumper arms 26a-c are disposed when extended in differing angular relationships with respect to the axis of the housing 20, each bumper arm 26 is preferably structurally identical. Each arm is shaped at one end with a reduced hinge portion 28, and by pin means 29 the bumper arm 26b is hingedly connected with the ring member 27 to hinge means 3% on the ring member 27. As appears in FIGURES 9 and 10, the bumper arms 26a connect by pin means 29 to hinge means 30a on the ring member 27, while bumper arms 26c through pin means 29 are connected to hinge means 30c on the same ring member 27. To swing the bumper arms 26 to the extended position of FIGURE 1 in pivotal action about the pin means 29, spring means 31 are provided, and such means may take the form of a hairpin spring wrapped about the pin means 29 and having one leg portion 31a bearing against the charge container 24, and another leg portion 31b pinned at 310 to each of the legs or bumper arms 26.

It was noted that the bumper arms 265 when swung outwardly to the position of FIGURE 1 define an angle of approximately 45 with the axis of the charge container 24,-and to limit the extent of outward swinging movement of the arms 26b, the ring member 27 is inachined or otherwise formed adjacent the hinges 30b with an inclined or tapered stop surface 27b. The bumper arms 26a, on the other hand, are disposed generally perpendicular to the charge container 24 when extended to the position of FIGURE 1, and to limit the extent of outward swinging movement of the arms 26a about the pivot 29, the ring member 27 is provided with a perpendicular or radially outwardly directed stop surface 2711 against which the arms 26a abut in the manner of FIGURE 9. With respect to the remaining bumper arms 26c, and as appears in FIGURE 10, the ring member 27 adjacent the hinges 30a is tapered as at 270 to provide a stop surface limiting outward swinging movement of the arms 260 about the pivot 29 to an angle of approximately 150.

Each bumper or guard arm 26 comprises a plurality of resiliently urged collapsible sections which are received within the profile of the explosive device A when the bumper arms are collapsed prior to dropping the explosive device into a body of Water for performance of a detonation mission. As appears in FIGURES 2 and 7, the arms 26 in their collapsed condition are held against the housing by wire means 32, which is released in response to action of the arming mechanism in a manner to be later described. Each bumper arm 26 desirably takes the form indicated in detail in FIGURES 3, 4 and 5, and it may be observed that there is provided a plurality of telescoping sections 33, 34 and 35. The outer section 33 of each bumper arm 26 is of tubular configuration and mounts at one end plug means 36 having a stepped outer diameter to provide a portion 36a tightly received within the tube section 33. The plug means 36 is formed at its opposite end with the earlier noted hinge portion 28 providing attachment through the pin 29 to the hinges 30 on the ring member 27. The tubular section 33 receives therewithin spring means 37 preferably positioned at one end by plug portion 36b and bearing at its opposite end against collar portion 38a on pin means 38. The spring 37 encircles pin portion 38b, and the opposite end of the pin 38 is formed with a portion 380 in tight fitting contact with the inner diameter of the intermediate tubular section 34. As is believed now quite apparent, the spring means 38 resiliently urges the intermediate section 34 to an extended position, and during the extensible movement, the pin collar portion 38a is in sliding contact with the inner diameter of the outer tube 33.

The intermediate tubular section 34 is in slidable contact with the outer tubular section 33 at the opposite end of the latter tube by means of an inwardly turned portion 331: formed thereon. The intermediate tubular section 34 is similarly formed at 34a with a swaged portion to slidably receive the central section of the bumper assembly 26. The central section 35 is desirably provided by a solid rod member as shown, and the rod section 35 slides relative to the intermediate tubular section 34 by provision of a head porion 35a formed on the rod section 35. Bearing against the rod head portion 35a is spring means 39, which bottoms at its opposite end against pin portion 380. Accordingly, through provision of the telescoping armsections 33, 34 and 35, and the spring means 37 and 39, the intermediate tube sect-ion 34 slides outwardly relative to the outer tube section 33 and the central rod section 35 slides outwardly relative to the intermediate tube section 34 when each bumper arm 26 is permitted to swing outwardly away from the housing 20 of the explosive device A through release of the wire means 32 or an equivalent thereof.

The wire means 32 prevents outward swinging movement of the arms 26 until the explosive device A has descended to a predetermined water depth, as will be explained in more detail in the succeeding paragraphs. Additionally, to maintain the bumper arm assemblies 26 in the collapsed condition illustrated in FIGURES 2 and 7, a pressing force is exerted against the outer end of each of the rod sections 35. This may be accomplished in various ways, as for example by abutting the rod ends against the inwardly facing ends surface of the fin collar 22. On the other hand, the rod 35 may be restrained to keep the arm assemblies 26 restrained by provision of a plurality of slots 39 formed in the fin collar 22, as best shown in FIGURES 2 and 7. Of course, during shipment of the explosive device A, container means may be provided about the collapsed assembly of FIGURES 2 and 7, and a form of cap means could be received about the lower ends of the bumper arms 26 to prevent extension thereof.

The bumper arm assembly described can readily be employed on various types of under water explosive devices, although particularly good results are obtained when the bumper arm assembly is incorporated into a demolition device having the arming and firing mechanisms of FIGURE 2. The structural details of these mechanisms will now be described, however, these details form no part of the instant invention.

The housing 21 provided by the main body portion 20 for the operating mechanisms is formed with a variable diameter axial bore 46 providing an annular firing chamber 47 housing a firin g mechanism designated generally by the numeral 48. Downwardly of the firing chamber 47 and inwardly of its opposite ends the body member or housing 21 is provided with a raised boss 49 having therein an annular recess 50 opening at one end and providing an arming chamber receiving an arming piston 51. Preferably cast integral with the body member 21, and thereby forming a part of said member, is an internally threaded collar 52 engaging a cap portion 53 of the charge container or canister 24. During use, the container cap portion 53 houses a booster such as tetryl, and the explosive within the container 24 may be in the form of TNT or other desired materials.

The firing mechanism 48 comprises a piston member 55 having a generally cylindrical head portion 56 and substantially cylindrical stem portion 57 passaged at 58 to slidably support therein a firin g pin 59 resiliently urged by spring means 60. It is to be seen that the firing pin 59 has a reduced diameter stem portion 61 surrounded by the spring means 60, and that the spring means bottoms at one end against the base of the passage 58 and at its opposite end against a shoulder 63 formed at the end of the firing pin reduced portion 61.

The piston member stem 57 is slidably received within a guide collar or insert 64 which is restrained against forward axial movement by abutment with a shoulder 65 formed by the firing chamber bore 46. The apertured insert 64 additionally functions to releasably lock the firing pin 59 in a rearward position, essentially as shown in FIGURE 2. This is accomplished by providing the piston member stem 57 with a plurality of circumferentially spaced holes or openings 66 receiving a ball member 67 of a suitable plastic or metal and seated in an annular groove 68 in the firing pin 59 axially inwardly of the opposite ends thereof. Therefore, the balls 67, groove 68 and apertured insert 64 lock the firing pin 59 in the position shown, and as will be later noted, travel of the piston 55 toward the arming chamber 50 causes the balls or rotatable elements 67 to be impelled outwardly, releasing the firing pin 59 from locked engagement with the piston member stem 57.

It is to be observed from FIGURE 2 that the firing chamber bore 46 is open at opposite ends, and communicates with the arming chamber 50 by means of a convergent passage 70. The opposite end of the bore 46, on the other hand, permits exposure of the piston head 56 to fluid pressures to cause piston travel when the explosive device A has descended to a predetermined depth in a body of water. The piston member 55 is restrained against axial movement in a direction opposite from the arming chamber Si) by loci: ring means or the like 71, and spring means 72 encircling the piston member stem 57 and bottoming at opposite ends against the piston head 56 and apertured insert 64 maintains the piston member head 56 against the lock ring 71. Lock ring means 73 may be employed at the opposite end of the piston 55 in surrounding relation to the stem portion 67 thereof, although this is of course not at all times required.

The arming piston 51 may comprise a generally cylindrical body portion 74 having a reduced diameter generally cylindrical neck portion 75 provided at one end thereof, and spring means 76 is shown as surrounding the neck portion 75 to resiliently urge the arming piston 51 downwardly from the position shown in FIGURE 2, and

' in an unarmed condition. Travel of the arming piston 51 may be guided by pin means or the like 79 attached to the walls of the boss 49, and cooperating with a notch or slide 80 in the piston 51 during its axial travel within the radial passage 50.

The arming piston 51 is in its armed position as shown in FiGURE 2, and formed in the arming piston body portion 74 for axial alignment with the firing pin 59 is a stepped diametral bore 81. The bore 81 in the configuration shown provides a pair of communicating compartments, and in the compartment adjacent the neck portion 53 on the charge container there is normally located a percussion cap (not shown). Viewing FIGURE 2, it will be understood that when the firing pin 59 is released from the position shown, the pin 59 travels first through the convergent passage 70 and then through the stepped diametral passage 81 in the arming piston 51 to detonate the percussion cap, which in turn ignites the booster charge in the charge container neck portion 53 by means of a hole or opening S2 in one of the boss walls. Ignition of the booster fractures or explodes a wall d3 separating the booster compartment from the main charge compartment, and thereby the entire charge in the canister 24 is detonated.

While, as earlier noted, effective utilization of the novel bumper means 26 of this invention does not require the specific arming and firing mechanisms described, in any arrangement wherein piston travel responsive to water pressures is provided, such piston movement may be employed to release the wire means 32. wrapping the bumper arms 26. In this manner, when the arming piston 51 is advanced axially inwardly in response to particular water pressures, the wire means 32 can be automatically released or disengaged so that the bumper arms 26 are in the position of FIGURE 1 after the explosive device A has descended a predetermined distance in the water.

If piston travel is utilized for wire release, an arrangement embodying the features of FIGURE 6 can be employed. As illustrated, the cylindrical portion 74 of the arming piston 51 is formed with an annular raised rib 74a providing a shoulder 74b against which may bear opposite ends 32a and 32b of the arming wire 32. The shoulder 74b is formed to provide a piston groove 740, the opposite side of which is formed by a shoulder 74d provided by another annular raised rib 75. It may now be seen that when the piston 74 advances in the direction indicated by the arrow in FIGURE 6, the release wire 32 will be advanced between the shoulder 74b and 74d until the grove 740 is aligned with openings 49a and 49b in the boss 49, whereupon by the inherent resiliency of the wire 32 and the tension applied thereon when the wire is wrapped about the bumper arms 26, the wire 32 will spring outwardly from the openings 49a-b to release the arms 26 for outward swinging movement to the position of FIGURE 1.

The underwater explosive device A may be suitably modified to detonate at various water depths, and illustratively, the device shown in the drawings may be armed at approximately twenty feet and fired at about sixty 6 feet. These exemplary depths may be varied as desired, and for this purpose there is provided on the housing 20 a threaded plug 77 (FIGURE 2) received in a threaded opening in the housing 20. In this manner, should it be desired to delay the depth of firing of the explosive device until water depths substantially in excess of sixty feet have been reached, the plug 77 may be removed prior to dropping of the explosive device, and water pres sures are thereupon exerted against the backside of the piston head 56 to prevent piston travel and firing until a particular water depth has been reached. Generally speaking, when the threaded plug 77 forming a part of the depth selector means is removed, firing will not occur until water depths of approximately 300 feet are reached.

Briefly stated, the explosive device A operates as follows. After the device A has been dropped into the water over an object to be demolished, and is guided to its course by the fins 23, a water depth of approximately 20 feet causes the arming piston 51 to travel axially within the bore '50 toward the closed end of the arming chamher, and essentially into the position of FIGURE 2, Whereat the diametral passage 81 in the piston body portion 74 is axially aligned with the firing pin 59.

During axial travel of the arming piston 51 from a position whereat the exposed face of the piston cylindrical portion 74 is generally flush with the open end of the piston chamber Sti, the annular groove 74c on the piston portion 74 reaches the openings 49a and 49b in the boss 49 to permit release of the arming wire ends 320 and 32b from the position of FIGURE 6. The arming wire :32 is accordingly released from its wrapping relation with the bumper arms 26, permitting the bumper arms to swing outwardly and causing the telescoping sections 33, 34 and 35 thereof to extend to their fully outward positions, as shown in FIGURE 1. Thus it may be seen that between the time at which the explosive device A is dropped into the Water and the time at which the device reaches approximately twenty feet, the bumper arms 26 are fuily extended, to protect the explosive device from intimate contact detonation while in contact with relatively blunt obiects.

Continuing with the operation of the device A, further descent in the water to a depth of approximately sixty feet causes firing to be initiated. This is effected by the relatively greater water pressures at this depth exerting a force against the firing piston head portion 56 through the relatively wide open end of the bore 46, causing forward axial travel of the piston 55 with the head portion 56 and stem portion 57 in sliding contact with the firing bore 46 and inner diameter of the sleeve or insert 64 respectively. Such movement is of course in resistance to the spring means 72, which acts to hold the piston member 55 in a rearward position with the piston head 56 against the locking spring 71, as shown in FIGURE 2. Continued axial travel of the piston stem member in sliding contact with the sleeve or insert 64 moves the rotatable elements 67 beyond the front face of the insert, whereby the balls or rotatable elements are cast radially outwardly through the apertures 66 in the piston stem 57 and out of locking engagement with the firing pin 59 through the groove 69 therein. The firing pin 59 is thereupon impelled axially forwardly under action of the spring means 63 and into firing contact with the percussion cap means in the compartment of the diametral bore 81 in the arming piston body portion 74. The explosive train is thereupon ignited by the percussion cap, firing the booster in the cap portion 53 and detonating the explosive material in the container or canister 24, to demolish the underwater object.

It has been pointed out hereinabove that effective avoidance of intimate contact detonation of an underwater explosive device does not require the firing and arming mechanisms disclosed in FIGURE 2 and specifically described hereinabove. The extensible bumper or guard means 26 may of course be time actuated to the position of FIGURE 1, or other arrangements may be provided to extend the bumper arms in response to water pressures. By the guard structure of this invention there is essentially no chance of intimate contact explosion of a detonatable device by contact between the device and a relatively blunt object, as typified by a submarine hull. As is known, submarine hulls normally do not have sharp or pointed objects protruding therefrom, although if the environment in which the instant explosive device is to be employed does upon occasion present sharp objects which the bumper arms :26 could straddle, the tips of the bumper arms could be spanned in various ways, as for example, by wire or fabric.

This modification and others apparent to those skilled in the art may of course readily be effected without departing from the novel concepts of this invention.

1 claim as my invention:

1. An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, means in said housing movable when the housing reaches a predetermined depth to detonate the explosive, and means connected to the housing and responsive to movement of said detonating means for erecting a barrier about the charge container to guard said container against intimate contact with underwater objects which may be unintentionally damaged by detonating the explosive.

2. \An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, means in said housing movable when the housing reaches a predetermined depth to detonate the explosive, and guard means normally disposed along the housing and movable in response to movement of the detonating means to space the charge container and guard the same against intimate contact with underwater objects.

3. An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, means in said housing movable when the housing reaches a predetermined depth to detonate the explosive, and a plurality of arm members pivotally mounted on the housing normally disposed along the axis of the housing and swingable outwardly therefrom in response to movement of the detonating means to space the charge container and guard the same against intimate contact with underwater objects which may be damaged by detonating the explosive.

4. An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, means in said housing movable when the housing reaches a predetermined depth to detonate the explosive, a plurality of extensible arm members mounted by said housing for outward swingable movement therefrom, and restraining means normally maintaining the arm members along the axis of the housing and released by the detonating means during movement thereof to permit outward swinging and extension of the arm members to space the charge container and guard the same against intimate contact with underwater objects which may be damaged by detonating the explosive.

5. An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, means in said housing movable when the housing reaches a predetermined depth to detonate the explosive, a plurality of spring-pressed telescoping arm members pivotally mounted at one end by the housing and restrained against extension along their free and opposite ends by said housing, and band means normally maintaining the arm members along the axis of the housing and released by the detonating means during movement thereof to permit outward swinging and extension of the arm members to space the charge container and guard the same against intimate contact with underwater objects which may be damaged by detonating the explosive.

6. An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, means in said housing movable when the housing reaches a predetermined depth to detonate the explosive, a plurality of extensible arm members mounted by said housing for outward swingable movement therefrom, a plurality of stop surfaces of varying degrees of slope supported by said housing and contacted by one end of each of the arm members to limit the extent of their outward swinging movement, and restraining means normally maintaining the arm members along the housing and released in response to movement of the detonating means to permit outward swinging and extension of the arm members to space the charge container and guard the same against intimate contact with underwater objects which may be damaged by detonating the explosive.

7. An explosive device adapted for underwater use, comprising a housing and a connecting container for an .explosive, a plurality of groups of hinge means supported by the housing adjacent one end thereof and arranged at different radial angles with respect to the axis of the housing, a plurality of spring-pressed telescoping arm members connected along one end to said hinge means, restraining means normally maintaining the arm members folded along the housing, and a firing pin assembly mounted by the housing and actuated by water pressures to release the restraining means and permit the arm members to swing outwardly on the hinge means, whereby the charge container is guarded by said arm members and shielded against intimate contact with underwater objects which may be damaged by detonating the explosive.

8. An explosive device adapted for underwater use, comprising a housing and a connecting container for an explosive, a plurality of groups of hinge means supported 'by the housing adjacent one end thereof and arranged at different radial angles with respect to the axis of the housing, a plurality of spring-pressed telescoping arm members connected along one end to said hinge means, a plurality of stop surfaces of varying degrees of slope supported by said housing and contacted by one end of each of the arm members to limit the extent of their outward swinging movement, restraining means normally maintaining the arm members folded along the housing, and a firing pin assembly mounted by the housing and actuated by water pressures to release the restraining means and permit the arm members to swing outwardly on the hinge means, whereby the charge container is guarded by said arm members and shielded against intimate contact with underwater objects which may be damaged by detonating the explosive.

References Cited in the file of this patent UNITED STATES PATENTS 2,568,712 Bowersett et al Sept. 25, 1951 2,923,238 Albon et a1. Feb. 2, 1960 FOREIGN PATENTS 602,400 France Dec. 23, 1925 692,686 France Aug. 5, 1930

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