Dec.10,1946. " RWBRITTON ' 2,412,387 AERIAL MINE Filed Dec. 2; 1941 2 Sheets-Sheet 1 Rob 21?‘ INVENTOR Patented Dec. 10, 1946 Ans? UNITED SATES NT 2,412,387 AERIAL MINE Roberta W. Britton, Ketchikan, Territory of > Alaska Application December 2, 1941, Serial No. 421,300 4 Claims. (01. 102-9) 1 2 This invention relates to the art of aerial de fense, and for its general object aims to provide a balloon-carried bomb device capable of being sent chamber occupying a diametrical position and aloft either by civilian or military ground crews intothe path of an attacking wave of hostile "planes. ‘ It is ‘a more particular object of the invention which is open at one end and at the other end is exposed to the atmosphere by an axial duct, and in' the wall of said chamber at longitudinally spaced intervals are openings H and l2 over which are applied percussion caps 13 and M func tional to the explosives Ill. Removably ?tted in to provide an aerial mine of this nature capable said bomb chamber is a shell or casing member 'of being exploded automatically in response to 15, and formed in the wall of this casing are open the rise of the mine to a predetermined and 10v ings It and I’! spaced in correspondencewith the ‘selectively variable height. openings II and I2 and held in registration wtih It is a still further and particular object to pro the latter by a set screw l8. Between the regis tering openings—which is to say the openings vide an ‘aerial mine in which the bomb charge is exploded by the force of impact of an attacking Il-l? and the openings |2—l'l—the casing is plane. Y ' .It is a still further object of the invention, look- 'ing to the safety of the ground forces; to provide divided longitudinally by a diaphragm 20 to de?ne separated cells at opposite ends thereof. Desig nated by 2|, the inner of such cells is supplied means for exploding the bomb charge in the event ‘with air through a neck extension IE’ on which ‘of the mine losing altitude as a result of "the is ?tted a knurled cap 23 for trapping the ad 20 mitted air at ground-level pressure; 'The’ other ' escape‘ of gas from the supporting balloon. Other objects and advantages, with the fore or outer cell is designated by 22 and is of a vari going, will become apparent in the course of the able-pressure nature in that the same is closed following detailed description and claims, the in only by a protective cover 2d vented as at 24’. vention consisting in the novel construction and In such latter or variable-pressure cell 22 is a in the adaptation and combination of parts here- ~iv Cl spring-loaded ?ring pin 25 functional to the per inafter described and claimed. In the drawings: Figure l is an elevational View representing the now preferred embodiment of the invention as cussion cap l4 and arranged to explode the latter - automatically in response to a rise of the aerial mine to a'predetermined height. The spring for the pin is denoted by 26, and as a means for nor the same appears in the air. Fig. 2 is a view taken to an enlarged scale and mally holding such spring under compression I illustrating the bomb device partly in elevation and partly in longitudinal vertical section, the supporting balloon being deleted. forward latching position by a hinged ?nger 30 abutting the back wall of the catch at the free end of the latter. Detailed in Fig. 3, it will be seen that said ?nger is set by lodging its free end _ Fig. 3 is a fragmentary transverse vertical sec tion taken to a scale enlarged from that of Fig. 2 and on line 3-—3 of the latter to detail the pres sure-controlled trip mechanism for exploding employ a catch 21 fulcrumed as at 28 and held in in'the notched extremity of one arm 3| of a bell crank. and the other arm 32 of the bell-crank serves as a trigger and is forked to straddle a ' stem 33 having thereon a tripping collar 34. Said Fig. 4 is a fragmentary longitudinal vertical 40 stem, which is attached to the diaphragm, ?nds section detailing the adjustment arrangement by a slide bearing in a cross-piece 35, and for-ad means of which I am enabled to set the bomb for justment purposes has its root end threaded to e?ecting an operation of the trip mechanism at a work in the threaded bore of a hub attachment selected height. 3B of the diaphragm. .7 Referring to said drawings, the bomb proper is It is believed to be clear from the foregoing denoted generally by the numeral 5 and has in its that theexpansion of the trapped air Within the the bomb charge; and periphery - a hanger-lug 6 ?tted with a ring 1 throughwhich is received‘ a suspension cable 8 from a balloon 9, the balloon having a governed displacement suf?cient to elevate the suspended - bomb toa height necessary for the interception cell 25 ‘caused by a lessening of the air pressure within the exposed cell 22 as the balloon-carried ‘mine risesto a‘ higher altitude causes the shifting collar 36 to trip the trigger arm 32 and ?re the '1"Th6 bomb part of the mine is or may be of a percussion cap M; coincident with the arrival of the bomb at a height predeterminately governed by the adjustment of the stem 33. It will of spherical form carrying a suitable explosive load course be understood that such automatic det of attacking planes. ’ , . I0, and is provided centrally with a cylindrical 55 onating system ‘may be rendered inoperative 2,412,387 4 through the instrumentality of threading the a distinct weapon separate and apart from the stem into the attachment S3 to the forward limit of its adjustment, in order thereby to locate the concussive force, and is especially effective against enemy personnel. Used either alone or in conjunction with anti-aircraft ?re of ground guns, losses of enemy planes can be expected to be quite high with casualties much more severe collar 3d such that its travel upon reaching the balloon’s ceiling level will be short of contact with the trigger arm 32. The end object of so ?xing . the parts is to permit the bombs to be sent aloft than has been heretofore experienced, and suf in advance of the arrival overhead of an at ?cient in fact to perhaps largely eliminate “level tacking Wave ofhostile planes, in consequence run” bombingas an effective medium of attack, laying a ?eld of aerial mines which, in their ll) losses considered. release, are regulated as to buoyancy character Describing now the structure which is em istic of the balloons to have the mines occupy ployed for exploding the bomb charge automati aerial levels within which the attacking planes _ cally upon a loss of altitude, there is provided will be expected to operate. Employed in this within the constant-pressure cell 21 a spring manner it is obvious that the pressure-differen 15 vloaded ?ring pin 40 functional to the percussion tial method of ?ring the bomb charges is not cap is and having its spring 4| held under com applicable, and that detonation must be accom pression by the lip of a bar 62 slidable longitudi plished either contact of the enemy plane nally in bearings £33. The bar lies in paralleling with the bomb, or by other suitable means of relation to a stem M which projects axially of control. I have illustrated the bombs as having 20 the cell from the rear face of the diaphragm, contact-detonating spine processes 3'5 formed and formed on the bar is a ratchet tooth 45. thereon, and it would seem as an adjunct to Carried by the stem in complement to the ratchet or in lieu of such detonating spines that radio tooth is a pawl lit, the arrangement ‘being one [waves might be advantageously employed to ac in which the ‘pawl tracks freely over the tooth tuate receiving sets carried by the aerial mines in the expanding forward travel of the‘diaphragm ‘or, as another form of control, that the mines but abuts the ratchet face to retract the bar and be equipped with a clock mechanism functioning release the ?ring pin lit} in response to acontrac to detonate the bomb charges upon the ex tive return travel of the diaphragm. 'piration of a predetermined time interval. While The invention and the manner of its usage is ‘not illustrated in the drawings, it may be fur ther mentioned that the efficiency of the mine from the standpoint of direct-contact ?ring would be augmented by having the suspension believed to be apparent from the foregoing de tailed description of the illustrated embodiment. ring l’ bear against a detonating trigger nor It is my intention that all forms of construction and variation in detail comingwithin the scope of the hereto annexed claims are to be, considered mally held in inoperative positionby a spring as comprehended by the invention. arranged to be overpowered by the force of a sud den tug upon the suspension cable 3, such for example as would occur upon Contact of a plane‘ with the balloon Q as distinguished from the sus What I claim is: 1. In an aerial mine, and in combination with a balloon adapted to be released at ground level: a ,bomb carried by .the balloon containing an pended bomb. explosive charge and providing mechanism op eratively associated with the charge for explod ing the latter, said mechanism comprising a normally inactive ?ring pin supportedin func tional relation to the charge, a spring applied ' To here bring out the import of the provision for exploding the aerial mine automatically in response to the latter’s rise to an adjustable pre determined height, appreciation must be had of the technique of mass bombing as it is now car as a powering load for the ?ringpin, displace able locking means for releasablyholding said spring under a compression set, .meansnormally ing planes over the target and, customarily, to inactive .to but .movable lintorengagement with have these said planes travel a level path ata said locking means for displacing the latter from ‘given altitude for some peI‘iOcl of time prior to JO its spring-holding 'positiomand means governed the actual release of the bomb load, the purpose by atmospheric pressure (and made responsive 'of this level flight being to facilitate a sighting to a rise of the balloon-suspended bomb to la ‘of the target by the plane’s bombardier. In predeterminedheight for causing the last-named using the present invention as a defense against ried out. The procedure, on the part of the attacking force, is to send waves of heavy bomb Li this said level-bombing attack, it is only neces~ means to act upon‘ the locking means and dis sary that the ground forces be enabled to de termine the altitude of the approaching enemy planes~and this information can be accurately transmitted from a high-altitude observation plane as well as by cross~checking ground in balloon adapted to be released at ground level; place the same from its spring-holding position. 2. In‘ an aerial mine: the combination of a and a bomb carried thereby containing an ex plosive charge and providing mechanism for ?r struments-and a multiplicity of the described aerial bombs are then released, having been ?rst set to thedetermined altitude for their explosion action. Given a large-scale bombing attack by enemy planes, it is, moreover, quite feasible to ing said charge, said ‘?ring mechanism compris release a score of the aerial bombs set for one hold the same in a loaded condition, means nor altitude, another score for another altitude, and still other scores of aerial bombs for still another altitude or altitudes, creating a barrier of ex ploding bombs substantially blanketing a given. rangeof altitude lyingin the path of the bomb ing planes. Itis not intended or necessarily expected that more than a few of the exploding aerial bombs will destroy attacking ‘planes by direct contact, but the ?ying shrapnel becomes ing a ?ring pin supported in functional relation to the charge, a spring for powering said pin to "?re the charge, displaceable locking means arranged to engage said spring and releasably mally inactive to but movable intoengagement with said locking means for-displacing the latter from its spring-holdingposition, and devices op- ' eratively associated with said locking means and made responsive upon a rise ‘of the balloon-car ried bomb to a predetermined height above its point of release to displace said locking means from its said spring-holding position'and permit the spring to assert its power in energizing: the : ?ring pin. 2,412,887 5 6 said charge upon a rise of the balloon-carried 3. Structure according to claim 2 in which bomb to a predetermined height assumed to place there is provided a second ?ring mechanism the bomb in the ?ight path of enemy planes; functional to the charge ‘and acting to explode and bomb-‘carried means also functional to said the latter in the event of the bomb rising to a charge and made responsive to changing atmos given height short of the elevation required to pheric pressures for exploding said charge at a operate the ?rst-named ?ring mechanism and lower level below said assumed ?ight path but then descending a distance less than the extent elevated a predetermined distance above the of rise. ground point of release, said last-named means 4. In an areial mine, and in combination with a balloon adapted to be released at ground level: 10 being made active only by a descending move ment of the bomb from a height above the ex a bomb suspended from the balloon and con plosive level last mentioned. taining an explosive charge; bomb-carried means functional to said charge and made responsive to changing atmospheric pressures for exploding ROBERTA W. BRITTON.