US2394896A - Aerial flare - Google Patents

Description

Feb. 12, 1946. J. F. cAvANAGH AERIAL FLARE `Fi1ed sept. 17, 1942 4 Sheets-Sheet l Feb. 12, 1946.

J. F. CAVANAGH AERIAL FLARE Filed sept. 17, 1942 l 4 shets-sheet 2 Feb. l2, 1946. J. F. cAvANAGH AERIAL FLARE Filed Sept. 17, 1942 4 Sheets-Sheet 5 Feb. 12, 1946. L F CAVANAH 2,394,896

AERIAL FLARE Filed Sept. 17, 1942 I 4 Sheets-Sheet 4 Patented Feb. 12, 1946 AERIAL FLARE l John F. Cavanagh, Providence, R. I., assignor to Kenney Manufacturing Company, Cranston, R. I., a corporation of Rhode Island Y Application September 17, 1942, Serial No. 458,677

(Cl. IGZ-35.6)

14 Claims.

Aerial flares of the type embodying a candle and a parachute with some form of sleeve or pilot for the latter within a case, call for means for effecting a chain of coordinated events between the release of the nare from a plane and its ignited state.

These events may be briefly described as the withdrawal of the parachute pilot, the removal of the inclosing case to release the parachute, and nally the ignition of the candle It is imperative that the foregoing events be effected with certainty at predetermined intervals.

Practice demands that the parachute shall be stabilized and the candle ignited at a predetermined point, usually approximately three thousand feet from the ground, and inasmuch as flares are released at various heights much above this, it is obvious that accurate and dependable timing means for releasing the parachute and effecting ignition must be provided if satisfactory operation is to be attained.

Heretofore pyrotechnic means involving various time factors and explosive force have been largely utilized in attempts to bring about the foregoing events.

The broad object of the present invention is to provide mechanical means for effecting the chain of events now brought about by pyrotechnic means.

By eliminating the use of pyrotechnic meansV for effecting release of the parachute and ignition of the candle at a predetermined point in the drop of the flare, and substituting therefor a mechanically timed release which is simple in structure and dependable in operation, I avoid the danger of the flare failing to function at the proper time, due to deterioration of the pyrotechnics, miscalculation in respect to the proper kind, quality, or volume of pyrotechnics used, and like factors making for defective or improper operation.

Another object is to provide the mechanical means with simple and dependable timing functions.

An outstanding advantage of the mechanical means for ejecting the case and electing ignition under the control of a calibrated spring motor resides in the fact that these functions may be carefully checked to the extent of actual operation before nal assembling in the flare. This advantage cannot be attained where p-yrotechnic materials are depended upon in any manner to time operations or effect the removal of the case.

Another object is to provide means for adjusting the timing function by remote control from a central point in the plane.

By constructing this mechanically timed release so that it may be adjusted by remote control, that is to say, by the pilot in the plane at the time he wishes to launch the are having regard to such factors as altitude, visibility and the like, I enable the pilot to overcome the groundset and frequently inappropriate timing adjust ment which was given the fla-re prior to flight and which may no longer be appropriate for the conditions existing at the time the nare isactually launched.

Another object is to provide an improved shade for the candle.

By constructing the shade for the candle as a plurality of fire-resistant sections separably attached to the candle so as to successively drop olf as the candle is progressively consumed, I avoid the necessity of using a single foldable shade of consumable material which not only must be `withdrawn from the case and accurately unfolded while the dare is dropping but when unfolded must always occupy a position suciently high above the ignited candle as not to be affected thereby. Where a single foldable shade is used, the shade must of necessity be supported at the top of the candle, and to make such shade effective when ignition starts, the shade must necessarily be of a length which tends to cause it to turn inside out as the nare falls.

Other objects and advantages of my invention will be apparent as the description proceeds.

As a result of these various improvents, my flare is simpler and cheaper to construct than flares of comparable type now in service and is far more dependable in operation.

In the accompanying drawings I have disclosed a preferred embodiment of my invention which well illustrates the principles involved. It is recognized, of course, that the invention is susceptible of various changes as to the form, size, proportions and construction and arrangement of its component parts, and all such changes are to be regarded as equivalents if they function in substantially the same manner to accomplish substantially the same purpose.

For convenience of illustration, I have omitted from such drawings those features'of the flare which form no part of my present invention but are standard equipment in flares of the parachute-supported type, such as the parachute itself, the arming wire-hangwire assembly, and like conventional parts.

Referring to the drawings:

by one as consumption proceeds.

Fig. 1 is a fragmentary sectional view of a flare in accordance with my invention, showing the various components in the position they normally occupy within the case before the timed mechanical release mechanism operates.

Fig. 2 is a similar view, foreshortened, showing the position of the parts after the mechanical release mechanism has operated to force the case away from the case contents.

Fig. 3 is an enlarged fragmentary sectional view at the nose of the are particularly showing the timed mechanical release mechanism.

Fig. 4 is a sectional view on the line 4-4 of Fig. 3 looking in the direction of the arrows.

Fig. 5 is a sectional view on the line 5--5 of Fig. 3W1ooking in the direction of the arrows.

Fig. 6 is an end view, as seen from the left, of the timing sleeve shown in Fig. 7.

Fig. 7 is a side elevation of said sleeve. Y

Fig. 8 is a section on the line 8-8 of Fig. 7.

Fig. 8a is a perspective view of said sleeve, and Fig. 9 is an end view of the nose of the are showing the time adjusting means.

Referring to Figs. 1 and 2, It is a conventional sheet metal case provided at its tail end with several rigid stabilizing vanes or fins I I.

In the flight of the flare, the rounded or nose portion I' of the case is downward and hence may be referred to as the bottom, while the end carrying the ns I I is upward and hence may be considered as the top. The upper end of the casing I0 is adapted to contain a conventional parachute and appurtenances (not shown).

Slidably supported within the lower end of case I0 is a tubular member I2 of suitable material adapted to retain a compressed illuminant composition I3, and having mounted on its exterior a sectional re resistant shade I4. Each shade section I4 is separately attached as at I4 to member I2 and each shade section comprises an annular sleeve portion Illa disposed about member I2 and a circumferential ange portion lli,b extending angularly downwardly with reference thereto. The angle of the ange is such as best to shade the ignited candle I3 when viewed from above and there is suflicient clearance between the -edges of the flanges and the inside surface of the case wall to permit the case and candle to separate from each other after the candle has been ignited.

The candle I3 is ignited at and burns from its lower end. As the tubular container I2 is consumed, the shades I4 successively drop off one While I have shown the several shade sections, as rigid with the candle, it is obvious that they might be foldable and of a diameter when expanded considerably greater than the diameter of the case.

'The lower end of illuminant member I2 is fitted with a sheet metal closure I5, which serves as a mounting for the spring motor housing I6.

Referring to Fig. 3, studs l'l are riveted t/'O closure I and serve to support motor housing I6 which consists of base plate I3, end plate I9, and spacer 20.

Mounted upon end plate I9 is a spring motor provided with a driving shaft 2l actuated by torsion spring 22. Rigidly mounted on shaft 2| isgear'23 to which one end of spring 22 is an= chored,A `while the other end of said spring is anchored to gear plate 24 which in turn is loosely mounted upon driving shaft 2! land retained against platen 25,

Referring to Fig. 4, it will be seen that platen 25 serves as a mounting for pinion 25 meshing with gear plate 24. The pinion shaft is squared as at 21 to receive a wrench or key for the purpose of winding driving spring 22. A pawl 28 engaging the teeth of gear plate 24 serves to lock the latter in any desired position with respect to the desired amount of tension to be imparted to driving shaft 2! by spring 22.

The inner end of driving shaft 2l is provided with a face plate covered with a coating of friction material 29 for a purpose aboutI to be eX- gplained. Mounted between end plate I3 and centrally attached to base plate I8 and spacedY from but in alignment with driving shaft 2I. Rotatably and slidably mounted upon stub shaft 34 is a sleeve 35 carrying a cam point 36, counterbalanced as at 36' (see Fig. 5). A friction washer 3l surrounding the inner end of stub shaft 34 and attached to base plate I8 serves to lock sleeve 35 in its stationary position.

A rock shaft 38 supported in brackets 33' attached to base plate I8 carries dog 39 for engagement with cam point 35 under the tension of spring 40. One end of shaft 33 is externally threaded to receive an adjustable collar 38a for adjusting the distance of overlap of dog 39 with respect to cam point 36. Two arms 4I also carried by shaft 38 are attached at their outer ends to friction wires in igniters 42 seated in base plate I8 in proximity to the rst fire composition I3 of illuminant container I2. Space has been provided between base plate i8 and firstv re composition I'3 for holding a highly inflammable composition i312, and suitable recesses ISb are provided in first fire composition I3' to insure effective ignition of said first fire composition I3 when said igniters 42 are actuated.

Pivoted at 43 upon base plate i8 is trigger 43 normally held by spring 43a under spring pressure against the side of case I0, as shown in Fig. 3. Pivoted with trigger 43 is a yoke comprising spaced arms 45 which engage sleeve 35 as at 45 (Fig.V 5) for the purpose of sliding the latter axially from contact with friction washer 3T into contact with friction surface 29 on driving shaft 2|. A projection 45 on said trigger normally engages a spring 4l on arms 45 and serves to hold sleeve 35 securely against the friction washer 3'! on base plate I8. A dog 43 on trigger 43 is arranged to engage a pin 4S on 'arms 45 when vsaid trigger is permitted to release through removal of case Ill, thus snapping sleeve 35 outwardly into engagement with drive shaft 2l.

Suitably mounted in the nose of case I0 is a spring seat 5E! upon which a powerful compreslsion spring 5I is seated and held in compression by spring retainer 52 through the functions of axially mounted locking members 55 and 52 about to be described. Projecting inwardly from spring seat 5G is a tubular member 53 provided with a lug 54. Positioned within said tubular member is adjusting shaft 55 provided at its inner end with a lug 55 similar to lug 54.

A gland 53 in seat 50 serves the double purpose of sealing shaft 55 against moisture and imparting a degree of friction to shaft 55 as safeguard against shock tending to turn it. A washer l of soft packing material is retained by the head of the gland as shown.

Mounted upon the outer end of shaft 55 is adjusting knob 58 (see Figs. l and 9) provided with an index pointer 59 adapted to register with dial 6E! on seat 5B. Knob 58 also carries a ser'- rated member 6| arranged to press into washer 51 under operating conditions to be described later.

A timing sleeve [52, detailed in Figs. 6, 7, 8 and 8e, is provided with a slotted head 63 and two spaced arcuate locking surfaces 64 and 65. Said sleeve is adapted to slip over tubular member 53 with its locking surfaces 65 and 65 normally en'- gaged with and retained by lugs 54 and 56 respectively. The sleeve head 53 serves to hold spring retainer 52 against the thrust of spring 5| while a ball thrust bearing 62 positioned as shown reduces friction in operation. The cross slot 63 in head 53 engages a cross pin 2| in driving shaft 2| to provide the turning means. The ends of a curved key member 55 integral with case nose IB positively engage and serve to so position spring seat 55 and end plate I9 as to insure predetermined timing relations between driving shaft 2| and timing sleeve 62. Spring seat 5l? is slotted as at 5de and end plate 9 is slotted as at i9 to receive the ends of key 56. When the release mechanism operates key 6B is withdrawn from slot I5' (see Fig. 2).

Reference to Figs. 7 and 8a will show that arcuate locking surface Sli is comparatively short and serves to normally hold spring 5| in compression against a small amount of turning motion of :f

timing sleeve S2 while arcuate surface 65 is long enough to permit a range of adjustment of its engaging lug 5, thus determining the portion of a revolution through which driving shaft 2| must turn before timing sleeve 62 releases spring 5l. As shown in Fig. 3, however, there is a small amount of clearance between lug 56 and its corresponding locking surface 65 while timing sleeve t2 is normally locked against rotation by lug 5d. This permitsfree angular adjustment of lug 55 through the function of knob 53 to iiX the number of elapsed seconds between the start of driving shaft 2i and the release of spring 5|. While I have shown two locking surfaces 54 and 65 and two lugs 5! and 55 as preferable construction, due to the fact that the thrust of the spring 5i is considerable and might eXert an excessive amount of frictional resistance to the adjustment of lug 5B, it is obvious that locking surface 6d and lug 5@- might be omitted under some circumstances.

After timing sleeve 52 turns enough to disengage from stationary lug 54, the thrust of spring 5| is taken by adjustable lug 55, which causes shaft 55 to slide outwardly suiciently to permit the serrations on member 6| to embed in the soft surface of washer 5l and thus lock shaft 55 against further angular movement until surface 65 functions to release spring 5|. This means of timing the release of spring 5| permits remote control of timing functions through utilization of a flexible shaft 5l detachably connected to shaft 55 as shown in Fig. 3, and operable by the pilot in the plane when desired according to conditions existing at the time that the are is to be launched, in which event, the plane can be equipped with a dial and pointer correspondingto that detailed in Fig. 9 for manipulation by the pilot.

It is common practice in ares of this type to attach a parachute to the upper end of the illuminant holder and incorporate said parachute together with its shrouds in folds within the case immediately above the illuminant holder. This arrangement requires a pilot or sleeve, attached to the top of the parachute, to effect the unfolding of the latter at the moment of release, and said parachute pilot together with its shrouds is also folded and packed over the parachute. The release of the parachute is effected by the removal of the metal case l0 during the course of the downward flight of the are. A cord or cable commonly called a hang-wire leading from the parachute pilot to a hook on the plane is provided, and the comparatively light cord 33 is attached to the hang-wire for the purpose of starting the timing functions when the flare has left the plane.

Assuming that a are has been assembled involving my improved mechanism, together with its parachute and pilot as just described, and that it has been mounted in the launching rack of the plane with the end of the hang-wire prop erly attached to the latter, the order of operations is as follows:

Practice has shown that a point approximately three thousand feet above the'earth is most advanta-genus for starting the burning of the illuminant. In these premises the timing device must be so adjusted as to permit the flare to fall a vertical distance corresponding to the difference between the point of release and three thousand feet before igniting.

If the height of the releasing point has been predetermined, this adjustment is ordinarily made before the plane leaves the ground, but in my improved mechanism, provision has been made for effecting this adjustment either` in the hangar, or while the plane is in the air. If ground-set, the adjustment is made by means of the handknob 58 and dial and pointer detailed in Fig. 9. If the adjustment is made during ilight, the lexible shaft 6l is used. The number of elapsed seconds between the start of timing shaftl 2| and the release of case il] through the function of spring 5| is determined by the position of lug 56 with respect to surface `|55 through adjustment of knob 58. The starting 0f timing shaft 2| is controlled by cord 33 attached to the flare hang-wire. 'I'hus it will be seen that the spring motor is not started until the flare has fallen a distance corresponding to a predetermined length of hang-wire.

The flare lis released in the usual way, and after it is free from danger of fouling the hangwire, draws' cord 33 releasing escapernent 30 when said cord 33 severs. The hang-wire then withdraws the parachute pilot and by means in common practice severs its connection with the latter so that the flare falls toward its destination guided by the ns on case l!) and the parachute pilot. When it has fallen to the three thousand foot height as determined by the timing adjustment, ejecting spring 5| is released, thus forcing case ID away from the illuminant assembly I3 and its attached spring motor (see Fig. 2) so that said ease and its spring 5| now fall free. In this action, the shaft 2| has been rotated by its clockwork through a suieient por tion of a revolution to cause the end of surface 65 to disengage from lug 5'8, thus releasing spring 5|.

The removal of case It frees the parachute, and its pilot thereupon functions to draw it out into condition for inflation so as to check the descent of the illuminant. The removal of case Hl likewise frees trigger 43 whichA functions to throw sleeve 35 into engagement with the friction surface E9 of driving shaft 2l so as to be slowly rotated thereby. After the required number of seconds to enable the freed parachute t stabilize, as determined by the relations of cam point 3S and dog 39, cam point 36 is rotated from beneath dog 3S, permitting arms 4l to operate under the impulse Vof spring 40 to jerk the friction wires of igniters d2 and ignite the candle I3. It may be stated here that these igniters 42 with their friction wires are widely utilized and constitute satisfactory and dependable means for eecting ignition of the candle.

The act of jerking the igniter wires serves to ignite first nre composition I3 in proximity to said igniters, and the burning of the illuminant begins. The end of the illuminant casing supporting'the motor housing I'B is immediately consumed and said housing drops free while the i1- luminant assembly floats downward supported by the parachute. As consumption of the illuminant proceeds, shades IG are released one by one.

Various modifications in construction and arrangement may obviously'be resorted to Within the spirit and scope of my invention as defined by the appended claims.

What I therefore claim as desire to secure by Letters Patent is:

1. An aerial flare of the parachute-supported type, comprising a case adapted to house an illuminant and its supporting parachute, a mechanical release mechanism for stripping the vcase from the illuminant and its supporting parachute at a predetermined point in the fall of the flare, a timing mechanism for controlling said release mechanism including a spring motor and a driving shaft, a normally-locked escapement in control of said motor, unlocking means for said escapement adapted to be actuated substantially coincidentally with the launching of the flare from the aircraft, and auxiliary timing means for igniting the illuminant, said auxiliary timing means being actuated by the Withdrawal of the flare case from the illuminant and its supporting parachute and when actuated being moved into coupled engagement with said driving shaft.

2. The flare of claim l, said auxiliary timing means including a lock for positively holding the same in a normally inoperative position.

3. The flare of claim 1, said auxiliary timing means including a rotatably and slidably mounted sleeve alined with but spaced from said driving shaft and having a cam, and there being, a spring-tensioned rock shaft having a dog disposed for coaction with said cam whereby after a predetermined degree of rotation of said sleeve said cam will release said rock shaft, and said rock shaft carrying ignition effecting devices for igniting said illuminant when said rock shaft is released.

4. The nare of claim 1 and a spring-tensioned trigger normally retained against actuation by contact with the wall of the case, a spring-tensioned yoke pivoted to said trigger and engaging Said auxiliary timing means for moving the same into coupled engagement with said driving shaft when said trigger is released by withdrawal of said case from its holding engagement therewith.

5. An aerial flare of the parachute-supported type, comprising a case adapted to house an illuminant assembly and its supporting parachute,

amechanical release mechanism for stripping the case from vthe illuminant assembly and its supporting parachute at a predetermined point in the fall of the flare, said mechanical release mechanism including a spring seat and a spring retainer mounted in spaced relation to each other within the nose of the flare case and a compression spring reactive between said seat and retainer, a timing mechanism including a spring motor and a driving shaft mounted in the flare case above said release mechanism and attached to the illuminant assembly, and quickdetachable means normally connecting said driving shaft with said release mechanism but releasable after the driving shaft has turned a timed distance thereby to release said spring so that it may expand and cause the case to be stripped from the illuminant assembly.

6. The flare of claim 5, and means adjustable at a point remote from the flare for changing the setting given said timing mechanism.

7. The flare of claim 5, and an angularly adjustable setting shaft spaced from and alined with said driving shaft and having a locking lug, and a timing sleeve keyed to said driving shaft and having a locking surface against which said lug normally bears but which surface is adapted to be withdrawn from said lug after said driving shaft has turned a timed distance thereby to release said springv so that it may expand and cause the case to be stripped from the illuminant assembly. f

8. The flare of claim 5, said spring seat having a sleeve portion provided with a locking lug, an angularly adjustable setting shaft rotatable Within said sleeve and alined With said driving shaft and having a locking lug spaced from said rst-named lug, a timing sleeve disposed about said sleeve portion and keyed to said driving shaft to rotate therewith and having a pair of spaced locking surfaces against which said lugs normally bear but which surfaces are adapted to be withdrawn from said lugs after said driving shaft has turned a timed distance thereby to release said spring so that it may expand and cause the case to`be stripped from the illuminant assembly.

9. The flare of claim 5, and an axially mounted sleeve within said spring and rotatable with said driving shaft and provided with an arcuate locking surface, an angularly adjustable setting shaft within said sleeve provided with a lug for engaging said `locking surface whereby said spring is retained in compression through the engagement of said lug and said locking surface, and means for adjusting said setting shaft to determine the portion of a revolution through which said sleeve must turn with said driving shaft to release said spring and effect disengagement of said case from said illuminant assembly.

10. The flare of claim 5, and a pair of normally interlocked axially alined locking members within said spring for normally maintaining said spring under compression, one of said locking members being rotatable with said driving shaft to release said spring and effect disengagement of said case from said illuminant assembly after said shaft has rotated through a predetermined distance.

controlled by the removal of said case from the parachute and candle for effecting ignition of the candle, and means whereby said ignition unit is released from the candle by the consumption of the illuminant in proximity to said ignition unit.

12. An aerial are, comprising a, case adapted to house an illuminant candle and its supporting parachute, a spring-operated ejecting unit at tached to said case for stripping the case from the candle and parachute at a predetermined point in the fall of the flare, a timing unit at, tached to the lower end of the candle, and means associated with said timing unit for igniting the candle at a predetermined time after the case has been stripped therefrom, said last-namedl means being released from the candle by the consumption of Vthe ignited illuminant in proximity thereto.

13. An aerial are comprising a case, an illuminant candle and a supporting parachute detachably mounted within said case, a release mechanism for stripping the case from the candle and its parachute at a predetermined point in the fall of the flare, and a plurality of re-resistant shades attached to the candle in longitudinally spaced relation to each other so as to successively drop away from the candle as the candle is progressively consumed.

14. An aerial flare comprising a case, an illuminant candle and a supporting parachute detachably mounted within said case, a release mechanism for stripping the case from the candle and its parachute at a predetermined point in the fall of the iiare, and a rire-resistant shade comprising a plurality of separate shade sections separately attached to the candle so as to successively drop away therefrom as the candle is progressively consumed, each shade section comprising an annular portion sleeved about the candle and an annular flange extending downwardly therefrom at an angle thereto.

JOHN F. CAVAN AGH.

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