US2402391A - Submarine detection - Google Patents

Description

Patented June 18, 1946 SUBMARINE DETECTION De Witt R. Goddard, Riverhead, N. Y., assigner' to Radio Corporation of America, a corporationv of Delaware Application August 30, 1943, Serial No. 500,479

2 claims. (ci. 177-386) 1 'I'his invention relates to a new and improved method of submarine detection. An object of this invention is to provide the means for eficient submarine detection having greater effective range than, as far as I am aware,

methods heretofore employed.

Another object of this invention is to produc a simple device to detect the presence of submarines or other submerged objects over great distances.

A feature of this invention is the` employment of both high explosive charges to generate sound waves and electrical means to time the echo of the sound returning from the submerged object.

The operation of the invention depends upon the idea of emitting a short pulse or sound in the water close to the boat searching for submarines and electrically recording the echo returning from the submarine.

The range of such equipment as used in the past has been limited due to the fact that electrical devices of limited power have been used to.

generate the outgoing sounds.

According to my invention I propose to use small charges of high explosive, thereby producing sound pulses in the water of far greater power or amplitude than has been possible in the past.

and will result in a greater effective range of submarine detection.

This invention will best be understood by referring to the accompanying drawing in which:

Fig. 1 shows an arrangement for discharging the explosive charges, and

Fig. 2 is a schematic diagram of the electrical recording devices.

Referring now to Fig. 1 of the drawing, a tube or magazine I has located therein a plurality of small bombs 2. These small bombs have built within their structure a small time fuse device and detonation arrangement similar to a Mills hand-grenade. The bombs 2 are located in a row within tube I and ejected by means of a plunger 3 containing a ratchet portion B which is notched 2. notches 6 to discharge one bomb from the end of the tube I. Such a discharged bomb is shown-at I4. In the operation .of a Mills hand grenade, the time fuse firing the charge is ignited byV an explosive cap. 'This cap is fired by a spring actuated striking piece or hammer which is held in the cocked position away from the cap by means of a hook-shaped piece'of metal indicated in Fig. 1 as a detonating lever i5. This lever or hookshaped piece of metal extends across the top or head of the bomb and along the side of its body as is shown. According to this invention. the detonating lever is retained in this position by the inside wall o'f the magazine. I. Normally whenV the hand grenades are used, the force of the hammer would throw oil the detonating lever allowing the hammer to strike the explosive cap.'

ao thrown. the force released causes the detonating to move forward by the pawl arrangement B on an armature 4. 'I'he armature 4 'is driven by the solenoid 8 and movable core 8 which is connected to the armature by means of a link I0. A stop II is provided to limit the motion of armature 4 and a spring I2 insures the return of thet armature against stop I I. Armature 4 is pivoted at the lower portion by means of a pivot l. A stop Il is provided to limit the action of pawl 5. Y

In the operation of this device. each time that the solenoid 8 is energized the plunger 3 is ad' However, this is kept from occurring by a suitably placed safety cotter pin and ring (not shown by the drawing). In manual operation, outside of a. magazine of this invention, the body of the grenade is grasped in the hand thereby holdingv` the lever against the grenade body in a manner similar to that mentioned above in connection with the magazine. The ring which is attached to' the safety cotter pin is previously taken out. In this manual operation, the only thing keeping the detonating lever from flying olf is the v hand of the operator. When the grenade. is

lever to fly oli! allowing the hammer to strike the explosive cap and a few seconds after the fuse has burned its full length, the grenade' explodes.

As mentioned. above, these bombs are built with a. detonating arrangement which requires` thelever it to be released. The release of lever IBv is accomplished by holding the detonating lever l5 against the 4body of the bomb and removing the safety cotter pin. Then the bomb is pushed into the forward end of the magazine I. The

bore of the magazine being of a suitable di ameter, keeps the lever I5 against the body oi' the -the moment the bomb leaves the inside, of the magazine tube as shown at I6; Themagazine tube is positioned to extend over the stern of the boat so thatthebombs will drop in the water.. .Ilv

few seconds later the fuse ydischarges the .bomb which in the meantime has sunk a few fathoms vanced the correct amount as determined by below the surface. The resulting high-intensity sound wave travels radially in all directions through the water. The sound wave is then kpicked up on a recording device 20 shown in Fig..

2 on board the ship. and provides a reference from which the time delay may be determined. From this reference, the distance traveled by the sound waves and its reoccurring echoes may be determined.

In Fig. 2 the bomb discharger'is shown as being electrically connected to an electrical timer 2i having a hand release button 22, a bell 23 and pickup devices 24 and 25. The timer periodically starts rotation oi! the recorder and also discharges a bomb into the water. The resulting explosion is picked up by the two pickup microphones 24--25 which may be located near the bow and stern of the boat respectively. These microphones record a mark on the recorder 20. Echoes from submerged objects are also picked up by the microphones and make their marks on .the recorder chart. By knowing'the recorder chart 'speed and measuring the distance between the initial mark yand the subsequent marks due to echoes, the distance and bearingl of submerged objects withinl the range of the apparatus may be ascertained.

f There are, of course, two possible bearings for each set of datal obtained, but this ambiguity may be removed by changing the course of the ship slightly and through the use of hand releas button 22 discharging another bomb.

The bell rings each time a bomb is discharged so as to attract the attention of the manon watch in order that he may inspect the chart for suspicious echoes.

While I have indicated and described a system of my invention, it willy be apparent toone skilled in the art that my invention is by no means limited to the particular devices shown and described, but that many modiiicationsmay be made Without departing from the scope of my invention. A

What I claim is:

l. A system for locating submerged objects comprising a tubular magazine containing 'a plurality of bombs of the type having an explosive time fuse detonating lever, each one of said bombs being arranged in a row within said tubular magazine so that the release lever is'retained inoperative thereby, a plunger rod having a pluyconnected to said timing system, a lpick-up device electrically'connected to said recording device whereby the distance oi submerged objects can be determined by measuring the elapsedztime.

between the exploding of said ejected bomb and the returning echoes.

2. A ksystem for locating submerged objects including a tubular magazine containinga plurality'of bo'mbs ofthe type having an explosive time fuse detonating lever, each one of said bombs being successively arranged within said magazine so that the detonating lever is retained inoper ative thereby, a plunger rod having one end extending within said tubular magazine, said plunger having a plurality of ratchet portions for periodically ejecting one of said bombs and thereby releasing said detonating lever so that the bomb automatically detonates a predetermined short time interval after ejection, a pivoted armature linked to said plunger rod, a pawl pivoted to said armature and arranged to engage thev ratchet portion of said plunger rod,` an electric solenoid, a movable core located within said sole'- noid and linked to said amature and forming part oi' a timing system, electric means associated with said timing system for periodically energising said solenoid/for actuating said. amature to'l eject one of said bombs, a recording device and a plurality ofV pick-up devices electrically connected to s/aid electric means whereby the distance oi'submerged objects can be determined by measuring the elapsed time between the explosion of said ejected bomb and the returning echoes. DE WITI' R. GODDARD.

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