US2374885A

US2374885A - Bombing apparatus for aircraft

Info

Publication number: US2374885A
Application number: US301675A
Authority: US
Inventors: Harry J Nichols
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-10-27
Filing date: 1939-10-27
Publication date: 1945-05-01
Anticipated expiration: 1962-05-01

Description

May 1', 1945.

H. J. NICHOLS BOMBING APPARATUS FOR AIRCRAFT Filed Co t. 27, 1939 3 Sheets-Sheet l ATTO R N vs y ,1 4 H. u. NICHOLS ,37

BOMBING APPARATUS FOR AIRCRAFT Filed Oct. 27, 1939 3 Sheets-Sheet 2 Y m mzd 2 '76 /o'7 y 1 1945- H. J. NICHOLS 2,374,885

I BOMBING APPARATUS FOR AIRCRAFT Filed Oct. 27, 1939 3 Sheets-Sheet Patented May 1, 1945 UNl'lED s'mrss harem OFFICE EOMBENG APPARATUS FOR AIRCRAFT Harry .l. Nichols, Binghamton, N. Y.

Application Gctober 27, 1939, Serial No. 301,675

25 Claims.

This invention relates to improvements inbombing methods and apparatus for aircraft. More particularly, it relates to an improved form of small fragmentation bomb, to a novel form of multiple launching means for such small bombs, and novel forms of fuses particularly adapted for use with these bombs, and the combination providing bombing means particularly intended for use by aircraft against moving aircraft. These novel forms of apparatus combine in a high degree the desirable features of safety, practicability, adaptability, and certainty in operation. Various forms of bombs and means for launching bombs are in use. In practice, bombs, when of explosive nature, usually exceed 20 pounds in weight and are individually suspended in bomb racks. Likewise, there are various forms of bomb fuses, but again with few exceptions they are armed by means of individual pull wires which are withdrawn to permit the fuse to arm, the arming force generally being supplied by a wind driven propeller. Such devices, while practical for larger bombs, are difficult to apply in a practical manner to small bombs, that is to bombs weighing less than twenty pounds.

It is therefore an object of the present inven tion to provide novel apparatus particularly adapted to the effective utilization of small bombs. A further object is to dispense with arming wires and wind propellers for arming bomb fuses, and to provide other novel arming means for bomb fuses characterized by safety, simplicity, and convenience and certainty in operation.

Another object is to'provide a novel means of suspending bombs in a bomb rack particularly adapted to the suspension and launching of a plurality of bombs in each rack.

Another object is to provide a bomb rack characterized by lightness and compactness.

Another object is to provide novel means for catapulting a plurality of small bombs, thereby to eliminate the possibility of the aircraft striking the bombs immediately after they are launched.

Another object is to provide novel types of bomb fuses characterized by reliability, simple components, ease of assembly and which can be manufactured economically in large quantities.

Another object is to provide novel means for arming bomb fuses, which means become entirely armed only in the act of launching.

Another object is to provide a settable time fuse for light bombs which fuse can be set at a particular time setting and can thereafter be set for another time or back to the safe setting without deranging the timing arrangements.

Another object is to provide a novel type of bomb fuse suitable for use without change to explode high explosive or low explosive burster charges.

Another object is to provide in a bomb fuse novel safety features which will minimize the hazard of detonation in case the bomb and fuse are exposed to fire, or the bomb is dropped prematurely or in a crash.

Another object is .to provide an economical form of burster charge for light bombs.

Another object is to provide a novel directimpact type of bomb fuse characterized by exceptional provisions against being exploded accidentally.

Another object is to provide a novel and effective method of attacking aircraft in flight.

Other objects will be in part obvious from the annexed drawings and in part hereinafter indicated in connection therewith by the following analysis of this invention.

This invention accordingly consists in the features of construction, combination of parts, the unique relation of the members, and in the relative proportioning and disposition thereof, all as more completely outlined herein.

To enable others skilled in the art to fully comprehend the underlying features of the invention, that they may embody the same by the several modifications in structure and relation contemplated by the invention, drawings depicting preferred forms have been annexed as part of this disclosure, and in such drawings like characters of reference denote corresponding parts throughout the views, in which-- Fig. 1 is a pseudo-pictorial diagram illustrating a typical collision dive attack according to the novel method of the invention.

Fig. 2 indicates the typical manner in which multiple bomb racks may be mounted in a pursuit or interceptor plane.

Fig. 3 shows in a somewhat schematic manner the general arrangement of the bomb rack forming part of the invention and indicating the manner in which the bombs are suspended in the bomb rack. 1

Figs. 4 and 5 show in detail at right angles the arming sprocket and sprocket retractor mechanism by means of which the bombs may be launched armed or unarmed at the optionv of the pilot.

Fig. 6 shows a detail of the catapult feature by means of which the bombs are launched with an initial acceleration over that imparted by gravity and the flight of the plane, illustrating the manner in which catapult springs are detached from the chains.

Fig. 7 shows details of the preferred type of construction for the bomb rack, and particularly an end plan View of the trip mechanism, in release position, on the spacer plate of the bomb rack.

Fig. 8 shows in section details of the trip mechanism by means of which the chains are released when it is desired to launch the bomb from a rack.

Figs. 9 and 10 show details of the upper and lower or double eccentric pawl retractor device,

as assembled in Fig. 8.

Fig. 11 shows the general form of a preferred type of bomb according to the invention, including a novel form of time fuse and the characteristic rack-teeth in the bomb vanes, and the guide grooves in the bomb body.

Figs. 12, 13, 14 and show sections of the bomb fuse and bomb of Fig, 11, the sections being taken as indicated on the lines 12-42, 13-43, I i-M and 15-15, the latter being about double in size to more clearly show the construction.

Fig. 16 shows in longitudinal cross section a fragment of the lower end of the bomb shown in Fig. 11 and a novel form of direct impact fuse in accordance with the invention.

Figs. 17 and 18 show a circular horizontal section and a vertical cross section of the arming ring of the bomb fuses shown in Fig. 16, the cross section being taken as indicated.

In order that a clearer "perception of the pres ent invention may be had and of the objects sought to be accomplished, reference is first made to Fig. 1 representing in pseudo-pictorial manner the relations between a bomber 20 and an attack plane 21 during a typical situation when employing the method of collision dive attack in accordance with the invention.

It is assumed that while the bomber 20 may have a speed exceeding two hundred miles an hour, the attack plane 2| will have a speed at least one-third greater, and during dives an air speed of one-half or more greater. Further, that the attack plane can climb at a greater rate than the bomber. Hence the attack plane can gain a position well above the bomber and to either side thereof and probably out of range of any gun carried by the bomber. The basic method of bombing attack with time bombs according to the present invention is that of a diving attack on a collision dive or constant angle of approach course between the attack plane and target in a three-dimensional zone. VIhile such an attack can be delivered from a course approximately over the bomber, attacks can also be delivered from above and from either side, as illustrated by the diagram.

This latter alternative greatly increases the difliculty of successful counter-fire from the bomber, since except for a few seconds during the dive, the attack plane can maneuver to present a constantly changing angle and distance as viewed from the bomber.

It is well known that when two vessels at sea are on 'a converging course, and the bearing of one relative to the other does not change, if such courseis continued collision of the two vessels will ultimately result, regardless of their initial distance and speeds. Such a course is termed a collision course and refers to their relation on a horizontal plane. Ordinarily, the course or speed of one vessel or both is changed to avert collision. However, assuming superior speed for one vessel, that vessel could, merely by maneuvering to keep the bearing constant, produce a collision regardless of the changes of speed or course of the other vessel. Likewise, by maneuvering to obtain and stay on a collision dive course, relative to the bomber, that of the bomber, that is a course substantially converging in space with the attack plane can produce a situation where bombs launched b it will continue on this course into effective range of the bomber. It is of course necessary to launch the bombs as circumstances permit to counter-act the bomber dodging either vertically or laterally to avoid the bombs after they have been launched, but as will appear from the following description, the means afforded by this invention minimizes the possibility of the bomber being able to do so successfully. To distinguish the method of attack of the present invention from the collision course method of attack on moving targets on the ground or water, the former is termed the collision dive method.

In connection with the following description of the diagram, some basic points regarding bombing should be noted. The first of these is that at the instant of launching, a bomb has imparted to it all the motional components of the launching plane. Thus the horizontal, vertical and directional components of the plane are reflected in the trajectory of the bomb. However, as soon as the bomb is dropped, gravity operates to increase the vertical velocity of the bomb. Neglecting air resistance, the trajectory of a bomb is a parabola tangent to the direction of the airplane at the instant of release, and for some time after the bomb is dropped, it will continue on directly underneath the plane if the plane were to continue on its course. The effect of air resistance is to produce a gradual lag, termed the air-1ag. of the bomb behind the plane. However, in a drop of only a few thousand feet, this lag is small and is immaterial in the present instance as will be hereinafter explained. Further, since the bomber, the attack plane, and the bombs after dropping are all equally affected by any wind present, the wind speed and direction is without material effect. Finally, it does not matter what the bombers speed, direction or ele- Vation may be, nor that of the attack plane, so long as the attack plane has speed, and climbing rate in excess of the bomber, and can maneuver to attain a collision dive from an elevation above the bomber sufficiently great to provide a,

sition of the attack plane is projected vertically downwards to the level of the bomber and this point is projected laterally to the bomber. The angle at is the angle between the course of the attack plane and the bearing line of the bomber, the angle 118 is the angle between the hypothetical vertical and the bearing line, while the angle 08 is the horizontal course angle of the attack plane relative to the bomber. These angles and projections are merely to make clear the geometrical relations and are of no concern to the pilot of the attack plane, who is solely concerned with the bearing line. The bearing line can be judged by the unaided eye with considerable accuracy, or more accurately by mean of a simple form of universal pelorus or other simple line of sight device.

As the pilot of the attack plane changes course towards the bomber, he notes in moving from point. 3 to point -6 that the bearing line moves forward indicating that his course if continued would pass back of the bomber. He turns his course to the right and downward to increase his speed, and at point 4 observes that the bearing line is stationary indicating that he is now on the collision dive course. It here should be noted that angles a4, a2, and all are equal; also angles b5, b2, and b are equal, hence the line of bearing is constant during this period. The angle of! is a true collision course angle. H continues on this diving course past point -2, and at point ll, judging his distance to be correct. launches a plurality of bombs set to explode at say from 4 to 6 seconds at half second intervals, or as desired. As soon as the bombs are dropped, from one rack .22 for example, the pilot pulls up to clear the bombs, and the bombs go forward in substantially the collision dive course represented by the dotted lines. The attack plane is in good position to start maneuvering for another attack on the same or accompanying bombers as necessary with the bombs in the remaining racks.

In the situation shown the bombs set at 4 seconds would explode well above the target bomber, those set at 5 seconds close above the bomber, and those set at 6 seconds below the level of the bomber. On exploding, the free:- ments of each bomb are projected along the trajectory in a conical pattern, thus in effect continually expanding the dispersion area of the fragments, as indicated by the dotted circle at the point of the diagram. Hence fragments of some of these bombs are virtually certain to be in efieotive range of the bomber.

The enemys opportunity for careful aim of his guns was virtually restricted to the course between points i and ll, a period of approximately four seconds. at which period the fast diving attack plane was say 3,000 to 2,000 feet away, under which conditions accurate gunnery from the bomber would be exceedingly difiicult.

It is obvious that the bomber would probably make some maneuver to foil the attack. Were such maneuver started before 'the bombs were dropped, the pilot can also change his course to keep the bearing constant, thus maintaining the collision dive course. Were the maneuver started after the bombs were dropped, very little time is available to materially change the bombers forward momentum which momentum in the case of a heavy, high speed bomber materially limits its maneuverability. Because of the high relative velocity of the attack plane to the bomber, which may easily be as great as 400 feet per second, the bombs set to explode at small. successive increments of time are launched with a high velocity towards the bomber. which velocity is augmented vertically by gravity.

Furthermore. the pilot can. by swinging or swerving the plane slightly at the moment of launching the bombs, further disperse the trajectory of successive bombs, causing them to spread or fall over an area instead of in a single line, thus obtaining a larger shot-gun pattern. This action, combined with the variable setting of the time fuses of the bombs, enables a veritable barrage of bomb fragments to be laid on and about the normal course of the target thus greatly increasing the probability of hits regardless of any sudden change in any direction attempted by the target.

The method of attack herein described assumes an element of skill on the part of the pilot, which skill is possessed to a high degree by military pilots trained in formation flying and bombing. Further, this skill can be augmented by practice against a towed sleeve target using the means and following the method of this invention. This is a feature of great.military importance, since practice with most anti-aircraft methods is exceedingly diflicult and costly.

Actual experience shows that trained pilots unaided by bomb sights can score a high percentage of hits against a ground target from heights as great as 2,000 feet, and it is easier to hit a moving target, following the method herein described, than it is to hit a ground target. Without further analysis, it should be apparent that the method of attack herein described is highly practical, and offers marked advantages in probability of effective hits and relative security to the attack plane.

Aircraft bombs are generally considered as means for demolition purposes, or strafing armed forces or civilian populations. In contrast, the principal intended purposes of the small bombs according to the present invention are for use in combating bombers, and for damaging of destroying enemy aircraft in the air or on the ground. The type of bomb equipped with settable time fuse is primarily intended for attack on aircraft in the air, or freely exposed on the ground. The type of bomb equipped with direct impact fuse is primarily intended for attack on aircraft housed in hangars. Hence bombs of the type here described may be considered primarily as anti-aircraft bombs. For this use, limited size and destructive power are advantageous. For purposes of comprehending the invention. the bombs can be thoughtof as weighing approximately five pounds. altho smaller or larger bombs within reasonable limits can be employed following the teaching of the invention.

Referring to the figures, showing the bomb racks and bombs in preferred form for carrying out the above method and particularly Fig. 3, the general scheme is to suspend a plurality of light bombs 23, say five, in each rack 24, the racks being suitable for mounting in multiple in a comparatively small space as shown in Fig. 2, so that a lar e number of bombs can be carried byeach light plane, of th pursuit and light interceptor types.

Mounting of racks in airplanes The mounting of the bomb racks 24 in aircraft is of course primarily the concern of aircraft designers and military authorities. For purposes of understanding the present invention, however. it seems desirable to point out that since gravity is not relied upon to launch the bombs, but supplementary catapult action is provided, the bomb racks may be mounted so that their length is substantially in horizontal aspect with relation to the longitudinal axis of the airplane body, or their length may be inclined upwardly and rear wardly. Furthermore, the bomb rack of the invention is of relatively small cross-sectional area, of light and open construction to permit easy accessibility to the mechanism, and the essential controls for launching the bombs can be situated remotely from the rack. These features facilitate mounting of the bomb racks in multiple, and they maybe arranged side by side and in layers if desired as shown in Fig. 2. Hence the invention provides unusual latitude and adaptability in the placement of multiple bomb racks, and contributes towards an eiiicient utilization of the plane load capacity.

Referring to Fi 2, the possibility of mounting multiple bomb racks 24 in inclined aspect inside and near the bottom of the fuselage of an airplane .is,illustrated. Suitable openings in the floor of the fuselage should of course be provided to permit egress of the bombs. It will be evident to those skilled in the art that the bomb racks of the invention lend themselves to preferred design considerations, particularly in adaptation to high speed pursuit and anti-bomber types of airplanes.

The bombs 23 are suspended in tandem between pairs of endless chains 25, ofgeneral similarity to bicycle chains. Preferably two of the four tail vanes 26 of each bomb are notched to provide rack teeth 21 adapted to mate with the links of the chain 25. The chains, and-the other vanes not engaging the chains, work in channel guides 28, Fig. 7. The bomb and fuse bodies are provided with grooves 30 in which the chains and guides are seated, thus to hold the teeth El of the vanes 26 in engagement with the links of the 1 chain 25. and to position and support the bombs in a secure manner at all times.

Each chain 25 is held taut between two sprockets 3 l32 which are mounted in suitable manner between brackets 33 attached to the spacer plates 36 of the bomb-rack frame structure, Fig. 3. The spacer plates 34 are held in rigid relation by suitable structural members, such as four cornerangle irons 35 welded to the plates in typical aircraft mode of construction. The guide channels 28 are assembled in notches in the spacer plates by welding in generally similar manner. Each spacer plate 34, except the trip mechanism plate, has a central circular hole of a size to permit the bombs 23 to pass thru readily.

Means to be described hereafter is provided to lock the chains 25 securel after the bombs are suspended in place, and to release the chains at the option of the pilot to cause the launching of the bombs in a rack. Means is also provided to arm the bomb fuses as the bombs emerge from the bomb rack on being launched, or to render the arming means non-operative to enable the bomb to be dropped unarmed.

The feature here to be noted is the means for catapulting the bombs in tandem sequence. The preferred means for accomplishing this is two long, tensioned catapult springs 36, generally imilar to those used for closing screen doors. Each spring is looped over a pulley El and hooked into the chain by a special fitting 38 so that a strong spring urge towards ejection of the bombs is imparted to each chain by the tension of its associated catapult spring 36. This spring urge, as well as the weight of the bombs, is sustained b the trip device of the release mechanism (Fig. 7) as will be explained in detail hereafter.

By inspection of the drawings it is readily seen that when the release device is tripped, and the chains thus freed, the catapult springs 36, to-

gether with any gravitational forces present, will propel the bombs from the bomb rack. This is primarily to obtain quick launching and to ensure that the bombs will be thrown entirely clear of the plane.

The chain release mechanism Referring now to Figs. '7 and 8 wherein the details of the chain release mechanism are shown,

this mechanism is preferably mounted securely on the next to top spacer plate 34 by a substantial center stud bolt 39 as shown. Each chain is securely held by a pawl 404l entering in between two rollers of the chain, thus preventing the chain from moving either up or down in the chain guide 28. Each pawl forms a part of and is actuated by a solid eccentric ring 42 fitting over an eccentric cam 43 rotatable therein. The eccentric cams, oppositely disposed, may be integral with a flanged pulley piece 44, the whole being rotatably mounted on the center stud 39. A flanged cap piece 45 i mounted over the pulley and eccentric parts, the pawls working through notches 46 in the cap piece 45, which latter is firmly secured to the spacer plate by screws 41 mounted in the flange thereof. A steel tape 48 runs in the flanged pulley, being secured thereto by a small screw Ell passing thru a hole in the tape, and being screwed into a radial hole in the pulley body 44. The tape ends pass thru slots 5| in the cap piece, these slots being disposed so that the tape can rotate the pulley approximately 180, the pulley being limited to this rotation by an arcuate slot 52 in the cap piece in which a pin 53 mounted in the pulley 44 moves circularly. One end of the tape 54 is attached to a stud 55 extending from the piston 56 in a spring tube 51 and working longitudinally in a slot 58 in the side of that tube. The spring tube is secured by suitable bracket pieces 60 on the spacer plate 34 beside the trip mechanism. The hollow spring tube has one end closed except for a central hole in which the piston rod 56' slides, and abutting against this closed end is a long, helical compression spring 6!. The other end of the compression spring abuts against the head 56 of the piston, tending to push same to the extreme right position of travel permitted by the side screw and slot as shown in Fig. '7. The other end of the steel tape 48 has attached thereto a pull wire 62 by means of which the chain release mechanism is tripped to release the bombs. The pull wire is extended, preferabl by a Bowden cable construction, to the bomb control handle within reach of the pilot or bomber. The bomb control mechanism beyond the pull wire does not comprise part of the present invention and hence is not shown or described in detail. Suitable control arrangements are provided on current bombing apparatus as is well known to those skilled in this art.

The operation of the chain release mechanism is as follows: To free the chains 25 to permit the bombs 23 to be loaded, the pull wire 62 is pulled outwardly as far as possible as shown in Fig. 7 and secured in place temporarily. The steel tape 48 attached to the pull wire is thus pulled out, rotating the pulley piece 44 clockwise and by virtue of the double eccentrics 43, retracting the pawls Ail-4| from the path of the chains 25. The spring 5! in its tube is further compressed by this operation or to the position shown in Fig. 7. When the bombs are in place in the bomb rack, the pull wire is released, whereupon the compression spring Bl pulls the tape and pulley piece 40 in the reverse direction, and by virtue of the double eccentrics, the pawls are extended into dotted position between adjacent rollers of the chain, Fig. 8. It is evident that since the eccentrics are on dead center, the pawls cannot be pushed inwardly, but can only be retracted by the rotation of the eccentric cams.

To release the chains, the pull wire is again pulled outwardly, thereby causing the eccentrics to retract the pawls it-4i to full line position Fig. 8 and thus release the chain 25.

It is well known that an eccentric permits a relatively high mechanical advantage to be obtained, particularly when started from deadcenter as in this case. Hence a relatively light force applied to the pull wire 62 enables the pawls to be withdrawn from the chain despite the considerable load thereon.

It is to be noted that the compression spring 6| acts on the release mechanism to hold the pawls always in the extended position, hence the chains can be released only by forcibly pulling the pull wire. In practice, accidental operation of the pull wire is guarded against by the Bowden cable and other suitable safeguards.

The arming mechanism Referring now to Figs. 3, 4 and 5, wherein the details of the arming sprockets and retractor mechanism therefor are shown, the arming sprockets 63 are each mounted on trunnion pins 64 working in slots 65 of a stationary channel piece 66, termed the guide, and a movable slide piece 61 working in the channel piece, termed the slide. The arming sprockets 63 are mounted to engage with the chains 25 on the side opposite the bomb 23, the teeth of the sprockets extending'between and slightly beyond the rollers of the chain 25 in the usual manner (Fig. Hence when in position of engagement with the chains, as a bomb passes the sprockets, the sprocket teeth pass thru the links of the chain and encounter and push in trip-pins 88 of the bomb fuse for the purpose of arming the latter.

To avoid arming the bomb fuse, it is necessary to withdraw the arming sprockets 53 from engagement with the chain, and mechanism for that purpose is provided as follows: The stationary channel piece or guide 66, with open edge disposed outwardly, is securely mounted between adjacent spacer plates 34. The inner closed edge of the guide abuts the bottom of the chain guide 28, and each guide is provided with a slot adjacent the sprocket to permit the sprocket teeth to pass through to engage the chain 25. Short closed slots 65 are cut in opposite sides of the guide 66 of a width suitable to provide working clearance for the sprocket trunnion pin 64. The slide 6'! is likewise channel shaped, but oppositely positioned with respect to the guide 65 and of dimensions to work easily inside this I guide. It is also provided with short closed slots H to receive the sprocket trunnion pin (it, but these slots are disposed at an angle of 45. Near the top of the slide is another short closed slot l2 extending longitudinally and adapted to receive a short guide pin [3- extending inwardly from the side of the guide 66. The purpose of this construction is to allow the slide ill to move longitudinally within limits, and also to permit the lower end of the slide 57 to swing outwardly around the guide pin '53 as a pivot. A tractile spring 74 mounted inside the slide at an angle. one end being fixed to the slide 67 and the other to the. adjacent spacer plate 34, normally to links.

maintain the slide 61 in' its downward and inward position as shown in Fig. 5. A pull wire 15, similar to that provided for the bomb release mechanism, is attachedto the upper end of the slide 61, and thence is led away to the bomb release controls. In practice this pull wire is preferably sheathed in a Bowden cable, altho no mishap is liable to occur because of accidental operation of this pull wire.

The operation is as follows: Normally the tension on the spring 14 holds the arming procket 63 so that its teeth engage through the chain When bombs are to be loaded in the rack, however, or if it is desired to drop the bombs safe, the arming sprockets must be retracted. To do this, pull on the arming sprocket wire 15. The slide 6? is thus pulled upwards against the tension of the spring 74, and in so doing, the angular slots H in the slide cam the trunnion pin 64 outwardly in the slots 65 in the guide 66, retracting the sprocket from engagement with the chain 25. The bombs can then move past the sprocket position without arming the trip-pins E8 of the bomb.

Assuming next that the sprockets 63 are to be made operative, the pull wire '15 is released, whereupon the tension spring 'l l acting on the slide cams the sprocket trunnion pin 54 towards the chain 25, and the sprocket 67 teeth again engage with the links of the chain.

It is to be noted that the notches 27 in the edge of the bomb vanes, whereby the bombs are suspended in the chains, must be cut in such relation to the trip-pins of the bomb fuse that the trip-pins will nest in the chain between two rollers. Otherwise the chain might push in the trip-pins prematurely, or else the pins would not be squarely engaged by the sprocket teeth.

It is to be further noted that the rack teeth 21 in the edge of the bomb vanes extend partly through the chain, and hence as they pass the arming sprocket, the rack teeth will strike the sprocket teeth. When this occurs, the sprocket is pushed aside, the slide 61 swinging outwardly to enable the sprocket trunnion pins 6 3 to recede from the normal position. After the rack teeth pass, the tractile spring l l restores the sprocket to engaging position for the next bomb. While the sprocket yields to the rack teeth, it ofiers sufiicient resistance to the trip pins 68 to push them in without failure.

Catapult mechanism Referring to Figs. 3 and 6, the details or the catapult mechanism are as follows: A long traction member of considerable strength is provided to exert a propulsive force on each chain. This member may be in the form of an elastic cord, commonly called Sampson cord, but is preferably in the form of a helical steel traction spring 36 as shown. One end of the spring '15 is adapted to be attached securely to a fixed part at the lower end of the bomb rack, the other end is fitted with the curved metal piece 38 of special form, termed the chain hook, adapted to be inserted between the roller links or" the chain 25 so that when the tension of the spring 36 is exerted upwards the hook is securely anchored to the chain, but when the spring tension is entirely relieved, the hook can be rotated and readily detached. Due to the special form of the hook, and other suitable arrangements provided, at the end of the catapult stroke, the hook will be drawn free of the chain, allowing the chain to run freely to ensure smooth launching of the last bomb in the rack, and to avoid shock on the chain Fig. 6. The spring is looped thru pulley or sheave 3.7 mounted on the under side of the next to top spacer plate 34. The traction spring, which is wound with initial tension, is of such length when not extended that the spring coils come solid when the shank of the hook is drawn into the sheave, in which position the hook is freed of the chain.

The operation of the catapult mechanism is as follows: During the operation of loading bombs, the catapult springs are. not hooked to the chains.

When the bombs are in place and the chains locked by the release mechanism, the hook is inserted in the lowest available link in the outside section of the chain. The traction spring is then drawn down and the eyelet in the end of the spring is hooked into the slot in the shank of the chain hook 33, which on application of the spring tension is locked in the chain,

On release of the chains, the catapult springs operate to eject the bombs in sequence. At the end of the spring travel, the shank of the chain hook 38 is drawn towards and into the sheave 31, where it is stopped by a check piece. As the shank is drawn into the sheave, the hook portion is drawn free of the chain, which latter is free to run until its momentum is expended. Thus the bombs are launched smoothly and without material shock to the launching mechanism or bomb rack.

Method of loading bomb in rack Because of the relatively simple arrangements provided by the apparatus, no prescribed procedure of loading bombs in the rack is necessary. The general steps are: Unhook catapult springs 36; set sprocket retractor wire 75 to safety position and secure; pull trip mechanism wire 62 to release position and secure; push the bombs 23 into the rack in tandem, leaving a small space between bombs as in Fig. 3 being sure that the last bomb is elevated above the arming sprocket po sition; release trip mechanism wire 63, assuring the pawls 40-4! properly to enter links of chain at desired level; hook up catapult springs 36; release sprocket retractor wire it to ascertain that the retractor mechanism works freely and re-set in safety position. Before flight, set time rings of the time fuses to desired settings. Before dropping bombs, release retractor wire l if bombs are to be launched armed.

The bomb Referring now to Fig. 11, the bomb 23, of streamline form, is provided with four vanes 28, two of these vanes being notched on the edge to form rack-teeth 2'! of suitable form to mate with the chain 25, while two vanes are preferably left plain as previously explained. The bomb body (and fuse body B'Sforming a continuation thereof) is provided with four grooves 36 mating with the chain and vane guides. This is to support and steady the bomb, and to ensure proper coordination of the chain links, trip pins 138 of the fuse (to be described later), and the fuse arming sprocket 65. The pilot or heavy end of the bomb has the fuse body attached thereto by heavy threads, or other suitable means of secure attachment. The bomb body is provided with a cylindrical barrel T! to receive the burster charge it (loaded in a shot gun shell) and rearwardly thereof a choke'orifice Bil, an expansion chamber 8| and at the outward end, a safety plug 82' secured in place by solder having a low melting point. The purpose of the choke orifice ti is to restrain the gases of the explosive charge, thereby to direct the main explosive force to the head portion of the bomb, yet to provide some egress of gases to the expansion chamber 8 I. The purpose of the expansion chamber is to lighten the rear end of the bomb, and to secure effective fragmentation of that portion of the bomb.

The purpose of the safety plug 82, is in the event of fire, to enable the gases distilled from the burster charge by heat to escape to the atmosphere, thus preventing a build-up of pressure sufficient to produce auto-detonation of the burstel charge.

The time fuse The time fuse is of a type generally similar to the time fuses long used for shrapnel and antiaircraft projectiles in that it is provided with a settable, graduated time ring 33 whereby the time of burst can be set anywhere in a range of 0 to say 15 seconds, in small increments. Also, the time ring can be set on safety, at which setting the time train is incompiete and in case of accidental firing of the primer due to shocks, etc., premature firing is avoided. There are two time train rings, one 84 stationary and the other 83 rotatable, each containing an annular, horseshoe shaped groove 85 in the rearward face of the ring. Fine powder is pressed in these grooves under heavy pressure to form the time train, the total length of which is several inches. Suitable port passage 85 or vents are provided to ignite the time train thereby carrying the flame from one ring to the other and thence to ignite the detonator 81, whereupon the explosion instantaneously proceeds via the detonating train to the burster charge.

The principal elements of the time fuse, in addition to the time rings 83-84, include the following parts; The fuse body which contains most of thefiring mechanism and is attached to the bomb body 23 by a screw joint 88; the cap 90 which screws on the body to form the point and to retain the time rings in place; the flash primer 9i located in the axial bore of the cap; the firing pin 92 and firing spring 93, held under compression by two safety balls 94 housed in a cylindrical sleeve 95; the safety gate 96 rotatably mounted in the axial bore of the fuse body and containing a detonating train of tetryl or the like adapted to transmit the detonating wave from the detonator 81 to the burster charge 18, the detonating train however being interrupted in the normal position of the safety gate; the torque spring 91 adapted to rotate the safety gate into armed position and to trip the firing pin 92 during the arming process; the safety ring 98 Fig. 17 normally restraining the safety gate, and the two trip-pins 68 radially positioned and adapted to start the arming process when both are pushed in simultaneously, and the expansion ring I00 normally holding pins 68 in extended position.

- The operation of the fuse is as follows: Assume that the movable time rin 83 has been moved from safety to some sitting, such as five seconds. Assume next that the two trip-pins 68 are simultaneously pushed inwardly as far as they will go, which action is effected by the two arming sprockets 63 as the bomb is ejected from the rack Fig. 3. The push trip-pins are normally prevented from moving inwardly by a circular wire expansion ring I00. Normally thetrip-pins engage the safety ring 98, preventing same from rotating. When its pins are pushed inwardly, however, the trip slots l0! move into such position that the periphery of the arming ring 98 can move or turn by reason of these trip slots. The safety ring is attached to the safety gate, which in turn is under the spring urge of the torque spring 9?, thereupon rotates, locking the trip-pins 63 in the inward position. The safety gate rotates the detonating train. I01 Fig. 13, into alignment with the detonator, and by reason of a square socket hole Fig. 14 which receives the square stem of the firing pin 92, causes the latter to rotate. As the head of firing pin rotates (two grooves H33 therein come into alignment with the safety balls 94, and slide over same, whereupon the firing spring 93 projects the firing pin Q2 into the flash primer 9!, exploding same. The flame from the primer passes thru the grooves M3 in the firing pin and thence into a cross-vent I94 leading to the sta tionary ring powder train H35, which latter is thereby ignited. The time train burns along its length until opposite the priming pellet in the port 86 leading to the movable ring 83, igniting the powder train 85 therein. The powder train in the movable ring burns along its length in the reverse direction until it reaches the priming pellet in the port HIE leading to the detonator 81, causing the latter to be ignited. The detonator explodes and the wave of detonation therefrom follows the side port in the safety gate to the central port ml, thence to the booster charge and burster charge 13, exploding the bomb.

In the safe position, the ignition train is interrupted at the flash cross-vent I05 by the head of the firing pin, and at the time rings 8384 when the movable ring is set on safety. The detonation train is interrupted at the point where the port leading inwardly from the detonator 87 meets the safety gate, which latter is normally positioned so that the explosive train liil therein is out of registry with the detonator as shown in dotted lines in Fig. 13,

Thus it is seen that adequate safeguards are provided to avoid remature action of the explosive train. Even in case the detonator were exploded by heat as in a fire, the explosion would be confined to the region thereof without exploding the main burster charge. With respect to the safety of the arming mechanism, it should be noted that in order to release the safety ring, both trip-pins 63 must be pushed in simultaneously against the relatively strong opposing force of the expansion ring Hi0. Such action can not be produced by dropping the bomb, or striking the bomb, since any single force tending to drive one pin inwardly will operate to tend to move the other pin outwardly. The expansion ring is strong enough to prevent premature action by pushing in the trip-pins in handling the bomb.

Thus it is seen that the novel arming features of the bomb provide adequate safeguard against premature arming of the bomb.

The burster charge can be loaded on automatic loading machines providing comparative safety and economy in cost of loading. The bombs can be assembled, transported and stored separate from the burster charges. The case of the cartridge can readily be sealed and water-proofed, keepin the charge in good condition. The case likewise avoids the possibility of dangerous chemical reactions between the explosive charge and the metal of the bomb body. Furthermore, the bomb can be readily unloaded if desired.

The burster charge, itself may consist of any suitable military explosive such as TNT, amatol or nitro starch. If desired, a supplementary booster charge of tetryl or the like can be loaded in a capsule mounted centrally in the base of the cartridge in place of the usual cap or primer.

Such booster charges are often advantageous to secure certain detonation of relatively insensitive military explosives.

The direct impact fuse The direct impact fuse Fig. 16 is generally of the same construction, and may be the same size and shape, as the time fuse so as to be interchangeable therewith. It consists of a body of rugged construction attached to the bomb by a threaded connection i l 0. It is fitted at the point with a cap ill, likewise by a threaded connection. This cap is of a material and thickness so as to resist ordinary shocks and blows thereon, but to yield to the impact of the bomb when dropped from a considerable height as would be the case in intended use.

The fuse body contains the firing mechanism and explosive elementscomprising the firing pin H2 extending partly in the cap and partly in an axial hole in the body and normally maintained in retracted position by a split ring l 13; the safety gate 56, torque spring 91, arming ring 98, two trip-pins G8, expansion ring H36, and the explosive elements comprising the detonator 8?, outward detonating train 83, shunt train 99 and inward train 187. All of these substantially the same in construction as those described in connection with Fig. 11.

The operation is as follows: There are'no preliminary arming operations. As the bomb is ejected from the rack the arming sprockets simultaneously push the two trippins 68 inwardly. As previously described, the arming ring is cleared by the trip slots iill in the trip-pins, enabling the torque spring 97 to rotate the safety ring 98 and safety gate thru an angle of 45, thereby bringing the ports of the detonator trains of the safety plug into alignment with the ports of the shunt train in the bomb body. This completes the train of detonation from the detonator to the burster charge.

On impact, the cap H! is pushed inwardly, forcing the firing pin H2 thru the split ring H3 and stabbing the firing pin into the detonator. This explodes the detonator, and the detonator wave travels outwardly thru the lower train in the safety gate, thru the side ports and shunt train in the fuse body back into the safety, gate, and then as inwardly to the center port and burster charge in a well known manner. "The safety features with respect to completing the train of detonation are as before. The firing pin is protected from premature arming by the cap. In the event the bomb is dropped without being armed as described, the firing pin may be driven into the detonator as described above, exploding same. However, the train of detonation will be broken as the wave leaves the safety gate, and the burster charge will not be exploded. It will be understood by those skilled in the art that I like.

plemmtary explosivematerial; is provided at the I I other cooling effects will render these gases in- .efiectivetor-start the detonation. I I I II The various detonating trains inIthis fuse, like= I I those of the time fuse, aretpreferablygloadcd'with 3 I =tetryl, rammed; in place and protectedatthe ex- I I posed ends by coating with a tough, water-proof varnish such as .a' celluloseacetate lacquer or the Tetrylis characterized by being compare-I I :tively easy to detonate by a iulminate charge, but will :not be detonated by heator flame; I I Without further description or analysis, it is considered evident that; the bombing equipment I I I I inaccordance with the inventioncombmesin a I I :high degree practicability; versatility, efficiency,

: convenience,- and other advantageous features I I WhatiscIaimed is: I I I I I Lin .a bomber airplane: a multiple bomb I I I catapult carried bytheiplan e, aplurality of bombs I mounted: in tandem therein, andcarrier means point of' change of direction. Hence, altho the II I gasesfrom the detonator and explosive train may leak into various parts of the fuse; expansion and I in tandem, propelling meanstendin to discharge 1 I I I said bombs forwardly; means .for. releasing the chain means, andmeansior arming the bombs I I they are propelled from the I hanne1 .I I 8.-Gatapult apparatus according to claim 7 in I I I I which the arming means on the bombs includes II I a depressible pin; and means cooperating there- I withior. depressing saidpin as thebombs are I I individually as ejected. I I

' El A catapuit bombracl: =for airplanes-inclum ingmeans for mounting a plurality of relatively I small bombs in; tandem relation, saidmounting means including I a pair of :spacedendless chains movably mounted onLsprockets and: adapted to 9:"; coact with the bomb for holding the same. sus- I I pended in the: rack; I propelling means. coacting I I with said. chains, mean ior holding the chains I I against Iniovement, and I means-for; releasing: the I chains whereby they mayimov'e toeicct thebombs from. the rack in tandem relation; I I I I I I i 10; Inanapparatus according to olaim 9 in I I II I eluding means coupled withthe chains for accel- I I I I I I I I I I I i I in said. catapult for carrying, arming, and eject- I crating their movement, but, automatically Iun- 1 I I I I I I I mg: said plurality: of bombs substantially simul '25 coupledtherefrom at the end ofsaidacceleration. I I I I taneously forwardly along the line of flight in ll; An apparatus according to claims includtandem formation. I I I I I :ing: spring propelling means acting upon said 2. Bombing apparatus as set: forthin. claim .l I II I I chains :for accelerating; their movement to cata- I I I I I I I I I I in which said bomb catapult is provided with a I I I =pult the:-bombs out through the .ends of saidrack. 1 I I I f I i I I i I I I I I I pair; of parallel: conveyorchains; of a length 3? I 12. An; apparatus according to claim 9 includ i I I I & suiifieientto carry a plurality ofbombsiintandem; I I ing 'meansu'ndersthe control of th :pilotfor re- I I I I I I I :3. In; abomber. airplane, a plurality of I indi I leasing the holding means for said chains where- I I I I I I I I I I viduallyoperable elongated multiple bomb cata -I I I I .bythebombs maybeejected: I I I I I I I I I I I pults mounted side by sidea into the construction I 1.3.; An apparatus according to claim :9 include I I I I of the plane and extending forwardlyand slightly 5 :ing' means for: moving the holding .means out of downwardly with: respectxto the: longitudinal axis I I i of the plane; in which each of saidbomb catapults. I

: I I I is; adapted :tocarry 2LT plurality of bombs in tan- I I dem, and includes chain conveyor means and: I I

means for forcibly projecting said bombs out through the forward end of said catapult in tandem salvo.

4. A bomb catapult for airplanes comprising an elongated structure adapted to hold a group of bombs in tandem and disposed in a longitudinal direction with respect to the length of the plane, chain conveyor means in said structure for carrying the bombs in tandem, means for urging said chain conveyor means rapidly forward, and means for releasing saidchain conveyor to eject the bombs forwardly as a group.

5. A bomb catapult apparatus according to cl'aim 4 in which the c0nveyor and ejectin means comprises a pair of endless conveyor chains arranged substantially in the same plane, and spring means cooperating with said chains to propel the same and the bombs carried thereby.

6. A bomb catapult for airplanes comprising a guide channel adapted to hold a plurality of bombs in tandem, structural means supporting said channel in a longitudinal direction with respect to the plane and with its dischar e end forward, movable endless chain means in said channel adapted to carry a plurality of bombs in tandem, and spring means for rapidly moving said chain means longitudinally and; forwardly in the channel to eject said plurality ofbombs in tandem.

'7. A bomb catapult for airplanes comprising a guide channel adapted to hold a plurality of bombs in tandem, structural means mounting said channel in a longitudinal direction with. respect to the plane and with its discharge end forward, movable chain means within the channel adapted to carry a plurality of unarmed. bombs cooperative: relation to said. chains whereby; said I i I chains are free" tomove in either direction I I t 14;: A catapult: bomb rack for airplanes I com- I I I prisinga skeleton structural assembly having a I I I bomb channel inthe axis thereof and adapted to I I mount in tandem therein a, plurality of bombs having individual arming means and support members therefor, and bomb supporting means associated with the rack including a pair of movable flexible carriers in said rack coacting with the support members on the bombs for holding same in launching position within the rack, means for propelling said carriers to discharge the bombs from said rack, and means coasting with said flexible carriers for arming th bombs individually as they are discharged from the rack.

I5. A catapult bomb rack for airplanes comprising a structural assembly adapted to mount two: or more bombs having arming means and supporting means associated therewith, apair of movable chains stretched in said rack coacting with the supporting means on the bombs for holding them in launching position within the rack, and means coacting with said chains for arming the bombs as they are discharged from the rack.

16. A catapult bomb rack for airplanes including a plurality of perforated spaced supporting plates, angle irons connecting said plates to form a rigid rack structure adapted to be carried by the airplane, sprockets mounted on the upper and lower supporting plates at opposite ends of said rack, a pair of co-planar endless chains passing, about said sprockets for supporting a plurality of unarmed bombs in tandem relation by engagement with opposite tail fins of the bombs, guide means for said chains, propelling means for said chains, and means for releasing the chains to carry the bombs out of the rack, said releasing means being under the control of the plane operator and including holding means cooperating with the links of the chain.

17. An apparatus in accordance with claim 16 including spring propelling means cooperatingwith the sprocket chains for accelerating their movement to eject the bombs.

18. An apparatus in accordance with claim 16 including means coasting with the chains adapted to arm the bombs as they leave the sprocket wheel out of engagement with the sprocket chain.

21. An apparatus in accordance with claim 16 including sprocket wheels cooperating with the chains having teeth passing between the ipintles thereof to arm the bomb as the bomb passes said sprocket wheels, and means for moving said sprocket wheels out of engagement with the chains, said means being disengage'able at the will of the pilot and upon release of said disengageable means automatically returnable to operable position. 1

22. In a bombing mechanism, a catapult comprising a pair of releasable bomb conveyor chains, a bomb mounted between and carried by said, conveyor chains including a streamlined body and head with a normally unarmed fuse with fuse arming means attached to said head, bomb arming means mounted on said catapult,

and notched guide fins at the tail end of said body for supporting the bomb in said bomb catapult by engaging with said conveyor chain and for registering said arming means in predetermined relation to said conveyor chains, thereby to enable said bomb arming means to coact with said fuse arming means when the bomb is catapulted.

23. Bombing apparatus in accordance with claim 22 in which said fuse arming means is adapted to be actuated on release of the bomb conveyor chains.

24. In bombing apparatus, in combination, an aerial bomb, a catapulting bomb rack therefor including bomb arming mechanism, and a bomb fuse for said bomb comprising firing means and detonating means, rotary means within the fuse adapted to rotate said detonating means from ineffective to effective position, and safety means entirely inseparable from the fuse and independent of the firing means for normally restraining said rotary means and adapted by co-action of the aforesaid bomb arming mechanism to remove such restraint.

25. In bombing apparatus, in combination, an aerial bomb, a catapulting bomb rack therefor including bomb arming mechanism, and a fuse for said bomb including therefor detonating means normally maintained in unarmed position, firing means and arming means within the fuse for said detonating means adapted to be acted upon by said bomb arming mechanism to arm said detonating means independently of said firing means.

1 HARRY J. NICHOLS.