US2449170A - Bomb fuse - Google Patents

Description

P 1948- J. B. Ma LEAN ET AL 2,449,170

BOMB FUSE 2 Sheets-Sheet 1 Filed. Nov. 8, 1943 INVENTORS JOHN 8. MAC LEAN [lg 54X E. SCHLENKEE A TTORNEX Sept. 14, 1948. J. B. MacL AN ETAL 2,449,170

BOMB FUSE 2 Filed Nov. a, 1943 v 2 Sheets-Sheet 2.

65 6 g 4 ea 82 a Flf Z v INVENTORS JOHN 5. WC LEAN ggi AX E. -.$CHLENKEE.

ATTORNEY.

v Figs-4 1s a schematicrdiagramillustrating Patented Sept. 14, 1948 s mates "HOIVIB FUSE JohnfiBL' MacLean and Maxi Schlenker, Peru; i

111., assignors .vtoiGeneral' :Time- Instruments e -Corporation;iNew York, N .--Y., a corporationl of- Delaware "ApplicationNovember 8, 1943, Srial No. 509;394

'4':Clalms. (Gl.102-84)- This invention relates in general i-to" bbmb 'fuze's :and "more particularly to v: fuzes' for -aerial dnop bombs arranged to' det'onate -a==predetermined time interval after being dropped from-a plane; The mainobject-l fthe invention is -to provide a mechanical time fuze of :this type which is normally safe and which arms #only a predetermined- I interval 1 after '-"the- "bomb leaves theplane.

According toone feature of the invention, the detonator is carriedby *a- 'movaible memberand is :normally held in a safe position but of "the path of 'movementof the-'ilrinepin; 'The release of the =detonator to armed position 1 iscontrolled by *the same timing mWem'ent which controls the release-of the fiiing 'pin 'to detonate the bomb.

Another feature of the-invention resides in -the manner in which the detonator slider is held'in safety position and released by'th'e-timirig' movement.'

According to a further feature-ofthe invention, the timing movement releases the de'tonat'or slider to armed position after a predetermined fixed interval which is less than theshortes't' interval= to which the firing -pin release mechanism maybeadjusted In some cases with certaintypes (if-bombs it is "the -'practice= to i install a fuze on the tai l of the b-ombas well as-0n thenose' of the bombJ This is an added precaution to insure-"detonation of the bomb atthe desired tim'e 'since if one fuze should fail the --other will detonatethe bomb. 'The'fuzes maybe similar in all respects exc'ept that the vane for the tail fuze is-some'wh'at longer;

to "insure =its proper operation by theair stream, and the arrangement of the-ball bearing assembly=is reversed fromthat-"'of-the nose fuze'x *For the purpose'ofillustration,*a'tail fuzeis disclosed and described herein;

The aforementioned "objects "and" features of the invention and others'not speciflcally'fpointed out above will become apparent and aclear. understandingof the invention mayibethad from a perusal of the ifollo'wing specification. whenread'" in connection with the accompanyingLdzawing,

comprising-Figs. 1 to 1, inclusive, inwhich:

, Fig.- 1 is a cross-sectional viewsof a complete tail iuze embodying :the present invention Y Fig.t2 isa-cross-sectionetaken alongethe line zflliofFigil;

Fig; 3 :is .a cross-section taken along cthe line 3 .3 0f -Fig. 1;.

'which' normallyllies:within thei groove'ri inner surface 50f bodyi 'l when ..-the; -head:is-;inserted' in the body 1 a: pluraii-tyiofescrews tsuchsias fl? aretscrewed 'do-wn 'ln iorde'rwto push:.thezspring v2 relationshipr.-and -'operation 0f :therfiri-ng pin release mechanism;zandz Figi f5 is 25 pBlSpeOtiVe VleWaOf thevheadnendrof :the.:fuze.

Referring; in" detail to the '3 drawingeythecfuze consistsz'essentially of ia 'body sectionl 'and- -':a

lieadassemblyr 2 rotatablyr-secured theretofi {Ihe head assembly E2 wcomprises a'casing, head-4 i havingca projecting portion: which extends :into the :cavity withinrthe "body 1|. Theihead-is retained within. the :body by; means :of eaizspring '2 wire -:5

wire "5 :part way into accomplementaryzzgnoove:in the cylindrical surface of headA: This .wsprm'g gether and rat tthe sametime permits the Zrhead fto' 'be rotated in ror'der ito :adiust'.the-etimeisetting of: the fuze :as will =be-explained later;

Asaran additional 1 precaution: the ccyl indrical surfaceiofthe :reduced portion of rhead TA is-iprovidedwith-.a-viurtherrgroove :6:and ';the bodyi'l ls hubibeingaslabbed: vonzone side 'so; that: the: vane :canmot turn thereon: The'vanevlil: is j retained against-ta shoulder :onrthe inner ballaraceclfi '-:by

provided withzholes-tr'ig adapted to receive aasuitable :wrench: so that" the nut-imay be tightened on thefi'hub tosecurely 1clampgthervan'e ontoithe inner: :bail .race.

Q'Ihe inner :ball raceumember has a;flangerportron 1| 5 x-whichi formshthe race rfcr' fthe' eballs i Hi.

This ass embly .iis'Tleldibnto :the'; headiilJoy; means 'GfibhGOHbl-if'bdll' race in :which isrsecuredid-the head 4 by means of screws such as II. A locating -;pin 1 2 is provided i toiiacilitate {the assembly improper relationship;-

From the foregoing it will beiseemzthatcthe vane assembly is rotatablewithin thex-hea'di as- The fuse disclosed =inathissapplicationa issdesi-gned Ifor" use' on theitaiL of a-bombi ,Thus;.--as

the--s=the :bomb is dropped theair stream pasty-the end of sleeve 2| is provided with a gear wheel 22. Both of these gear wheels'are in mesh with an elongated pinion 23 mounted on the pinion pin 80 whose right hand end is driven into the head portion 4 and whose left hand end is supported in a hole in the plate l3 Whichis clamped vbetween the outer ball race In and the head 4.

Gear wheel 22 has one more tooth than gear wheel I8 and as the vane assembly is rotated 'by the air stream as the bomb is falling, the rotation of gear Wheel l8 rotates pinion 23 which in" turn rotates the gear 22. In View of the difference in number of teeth, the gear 22 and the sleeve upon which it is mounted gradually rotates relative to the hub I1 and as it rotates its left hand thread screws out of the hub l7 moving the sleeve to'the right as viewed in Fig. l. The pinion 23 is long enough so that both gear wheels stay in mesh therewith until the sleeve 2| has been completely screwed out of hub II.

The sleeve 2| is provided with a center bore through which extends the firing pin 28. This firing pin is provided with a striker 26 in threaded engagement therewith and the striker is locked on to the pin by means of the striker nut 21 and lock washer 19. r

The sleeve 2| as shown'in Figs. 1 and extends beyond the vane nut 20 and into the central hole of a safety block 25.

This circular safety block has part of its wall cut away so that it can become disengaged from the head assembly when the sleeve 2| is moved to the right by the The right hand end of hub I7 is provided with a gear wheel l8 and the right hand in the body by means of screws such as 53. This timing unit forms no part of the present invention and has, therefore, merely been indicated in the drawings.

It is suflicient for the purpose of this application to state that the hub 41 is rotated by the timing unit at a predetermined rate determined by the time range desired for the particular fuze. Secured to the hub 41 is a cam and disc assembly comprising the timing disc 5|, the hub portion 50, and the cam 49 which is mounted on the hub 48. The firing pin 28 extends through a central hole in the disc, hubs and plates of the timing unit.

As illustrated more clearly in Fig. 4, the firing pin is held in its cocked position by means of the engagement of the firing pin ring 33 with the slabbed portion of the cocking pin 35. The

rotation of the vane assembly. However, as long as the sleeve is in the position shown in the draw- 'ingthe safety block can not be removed and it 'serves as a safety device to prevent operation of the firing pin.

-' A striker stop 29 is normally wedged between the striker and the safety block to keep the tension of the firing pin spring from the cocking pin. This striker stop is removed when the bomb is mounted on the plane.

Fastened within'the cavity in head 4 is a firing pin spring sleeve 30 which is retained in the pin ring 33 which is pinned to the firing pin by pin 34. In its set position, as shown in Fig. 1, the firing pin ring 33 is in engagement with the slabbed surface of a. cooking pin 35 rotatably mounted within the head 4. This cocking pin 35 is provided with a cooking pin screw 36 which extends beyond the head 4 into the space within body 'A channel is provided in head 4 for the passage of the cocking pin screw 36 when the cocking pin is rotated.

Mounted within the body is a timing unit indicated generally by the reference character 45.

' This timing unit is made up of a number of plates such as 46 which are held together by means of suitable screws. The timing unit is retained cocking pin screw 36 is retained by the hook 39 of the firing lever 31 which is mounted on the head 4 by means of screw 38.

The tail 40 of this firing lever is in engagement with a laterally extending projection 43 of the timing disc lever 4| which is also mounted on the head 4 by means of screw 42. The bent up portion 44 of lever 4| serves as a cam rider and is in engagement with the periphery of the timing disc 5|. Thus the spring pressure of the firing pin spring 32 tends to rotate the cocking pin 35 in a clockwise direction as viewed from the left in Fig. 4 and the pressure of the cooking pin screw 36 against the inner camming surface of hook 39 tends to rotate lever 31 in the direction indicated by the arrow. This force is in turn transmitted to lever 4| tending to rotate this lever in a counterclockwise direction as indicated by the arrow, thereby maintaining the cam rider 44 against the edge of the timin disc 5|. The timing movement 45 is in wound condition and tends to turn the hub and cams mounted thereon in a counterclockwise direction as seen in Fig. 3. The movement is prevented from operating by means of an arming pin 68 which has a reduced end portion 69 normally in engagement with the notch 52 in the timing disc 5|. This arming pin 68 has an enlarged head portion 1| which is retained in position by an arming wire (not shown) passing through the hole 12 and holes in the arming pin bracket 13. The arming pin is urged to the right by means of the arming pin spring 10.

The body is provided With a transverse bore in which is contained the detonator slider 54. Slider 54 carries the detonator 55 and is normally held in the position shown in Figs. 1 and 2 of the drawing with the detonator out of the path of operation of the firing pin. The slider is held in this position by engagement of the shoulder 82 (Fig.2) with a slabbed portion of the arming stem 60 which is rotatably mounted in the body This arming stem 60 is bent over at its left hand end as seen in Fig. 1 to form a cam rider portion 62 which normally rests on the cam 49 as seen in full lines in Fig. 3 of the drawing.

The arming stem 60 is provided with a groove engaged by a screw 6| in order to retain it in proper position. The detonator slider 54 is urged to its armed position by means of the slider spring 51 which is contained in the hollowed out end of the slider 54 and bears against the slider retaining plate 58 which is held to the body by means of screws 59. The other endof the slider is reduced in cross section and is adapted to slide in and is guided by the bore 56 when the slider is moved to armed position. A-groove 83 is provided in' the slider body and this groove amort ze "fid is contained-a slider-lock 'pin 65 which is adapted to enter thedepression 63 and lock the slider in armed position when it is movedto such armed position by means of spring 51. The pin 65 is urged to the left as'seen in Fig. 2 by means of the locking pin spring 66 which is maintained in position bythe closure screw- 61.

The right hand-end of 'thefuze body isprovided with external threads 1 by means of which the fuze is screwed into the body of a bomb. The fuZe is also provided with a booster cup 8 threaded into the fuze body at 9 and this bOStel'g1 cup is filled with a booster charge indicated at 75. A hole is provided through the right end wall of the fuze body I to communicate between the detonator 55 and the booster charge and this hole is provided with a closure cup 14 to prevent the booster charge from entering the fuze body.

Referring particularly to Fig. 3 of the drawing, it will be seen that the time of detonation of the fuze after the arming pin 68 is removed depends upon the relative position of the cam rider 44 with respect to the notch 52 in the timing disc. This relative position may be adjusted by rotating the head assembly within the fuze body I. A scale is provided on the fuze head which scale cooperates with a zero index on the fuze body to indicate the time setting of the fuze. When the bomb to which this fuze is attached is loaded in the plane, the striker stop 29 is manually removed. Th arming wire which retains the arming pin 68 in position and which also passes through a hole in vane I9 is then attached to the bomb rack.

When the fuze is dropped this arming wire is pulled out, thereby releasing the arming pin 68 which is forced out of the notch in timing disc 5| by means of spring ill. The timing movement 45 therefore begins to operate, turning the timing disc El and cam 49 in a counterclockwise direction as seen in Fig. 3. Approximately three seconds later the cam rider portion 62 of the arming stem 60 drops off the cam 49 and assumes the position shown by the dotted lines in Fig. 3. Rotation of the arming stem Eli releases the shoulder 82 of the detonator slider and this slider is moved to armed position by spring 51 carrying the detonator 55 directly into line with the firing pin 28. As soon as the bomb begins to fall through the air, the air stream rotates vane l9 and by means of the differential action between gear wheel !8, pinion 23, and gear wheel 22, the sleeve 2| is screwed out of the hub l1 moving to the right to withdraw the left hand end thereof out of the safety block 25. As soon as the sleeve is removed from the safety block, the latter drops off of the fuze, being thrown out by centrifugal force, thereby clearing the striker head so that the firing pin can operate to detonate the fuze after the elapse of the set time interval.

The timing disc 5! continues to be rotated by the timing movement until the notch 52 is engaged by the cam rider 44. The rider 44 drops into the notch causing lever 4! to rotate and the projection 43 to disengage the tail 40 of lever 31. The cooking pin screw 36 therefore cams the hook 39 out of the way and permits the cocking pin 35 to rotate, disengaging its slabbed latching edge from the firing pin ring 33. As soon as the firing pin is released the spring 32 forces 6 "the'firin'g "pin -28 'toitherightias. seen inili'igz-iil,

causing the *poiriter' end fof-rthe .pinr'to :enterflthe detonator fifigexplo'ding the-charge whichzis'ztransmitted I to the booster :charge' 115. This -t in :turn

Referring lt'o Figi" 3, the fuze vcan be adjusted to -a minimum ritime interval of approximately 5 seconds. Thus ith'eirider '44 which is.in engagement withlthe timing disc 5 l :caniberotated: to :a

position seen.above ithe-notch 52, but teventrwith this setting it will be'apparent that ithe :arming stem.cam.rider. 62 will disengage cam 49 in order to .arm theifuze.beforezrider 44 enters notch 52 to detonate the fuze. Thus, the delay interval for moving "thede'tonator -from*safety to armed position-(is Jfixed whereas -the time -interval between the release of the bomb and detonation of the bomb may be adjusted to suit the particular requirements. However, the detonator is always moved to armed position before the firing pin can be released by the timing disc 5|.

The particular embodiment of the invention disclosed and described in this application is a fuze adapted to be used on the tail of a bomb. However, as pointed out above, the fuze is equally adaptable for use as a nose fuze, it merely being necessary in this case to reverse the ball race to provide the proper bearing surface for rotation of the vane assembly. A shorter vane may be used when the fuze is used as a nose fuze.

Although only a particular embodiment of the invention has been disclosed herein, it will be apparent to those skilled in the art that various modifications and changes may be made Without departing from the spirit of the invention as defined in the following claims.

What is claimed is:

1. In a bomb fuze, a spring biased firing pin, a latch for holding said pin in cocked position, a mechanical time movement and a cam driven thereby, means controlled by said cam for releasing said latch, detonator carrying means and means for moving same to armed position, and a second cam driven by said time movement for releasing said detonator carrying means.

2. In a bomb fuze, a spring biased firing pin, a latch for holding said pin in cocked position, detonator carrying means and means for moving same to armed position, a mechanical time movement, a cam controlled by said time movement for releasing said detonator carrying means after a fixed interval, and a second cam controlled by said time movement for releasing said latch after a predetermined adjustable interval.

3. In a bomb fuze, a spring biased firing pin, a latch for holding said pin in cocked position, a detonator carrying means and means for moving same to armed position, a timing device and a shaft rotated thereby, means normally holding said shaft in a zero position, means for releasing said shaft to start said timing device, a cam on said shaft for controlling said latch to release said firing pin after a predetermined adjustable interval, and a second cam on said shaft for releasing said detonator carrying means after a definite fixed interval.

4. In a bomb fuze; a spring biased firing pin axially mounted in said fuze; a detonator carrying means normally held in safety position with the detonator out of alignment With said firing pin; a timing device; a shaft surrounding said firing pin and rotatable by said timing device; a cam cooperating with a follower for releasing said detonator carrying means, said cam being secured to said shaft; a second cam cooperatlog-with a cam follower for-releasing said firing pin also secured to said shaft, said cams and cam followers being so positioned that the former cam and follower must release the detonator carrying means to firing position before the latter cam and follower can release said firing pin; means to prevent the movement of said cams from zero position before the bomb has left the bomb rack; and means to adjust the interval between the start of said cam movement from zero position and the release of said firing pin.

JOHN B. MACLEAN.

MAX E. SCHLENKER.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 8 UNITED STATES PATENTS Name Date Zornig Aug. 10, 1937 Zornig Sept. 28, 1937 Bold Feb. 13, 1940 FOREIGN PATENTS Country Date Great Britain Feb. 16, 1928 Great Britain Aug. 3, 1933

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