US2420237A

US2420237A - Bomb fuse device

Info

Publication number: US2420237A
Application number: US655119A
Authority: US
Inventors: Philias H Girouard
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-02-03
Filing date: 1933-02-03
Publication date: 1947-05-06
Anticipated expiration: 1964-05-06

Description

May 6, 1947 P. H. GIROUARD BOMB FUSE DEVICE Filed Feb. 3, 193s 2 Sheets-Sheet' 1 May 6, 1947. P. H. GIROUARD Filed Feb. 3, 1935 2 Sheets-Sheet 2 Patented ay 6, 1947 Iren s TES (Granted under the act of March 3, 1883, as amended April 30, 192.8; 370 0. G. '757) Claims.

This invention relates to a fuse for an aerial bomb and has for one object to provide a fuse of the type mentioned having a propeller that will be actuated by wind pressure above a bredetermined magnitude to arm the fuse but to unarm the fuse if the wind pressure decreased below that value.

A further object is to provide means to unarm the fuse if the wind pressure is directed across the axis of the bomb, as would be the case if the bomb should catch on a plane after having been released from the bomb rack and so hang with the axis of the bomb transverse to the fore-andaft line of the plane.

In the drawings:

Fig. 1 is a longitudinal section of my invention assembled in the nose of a bomb;

Figs. 2 and 3 are transverse sections on lines iand respectively, of Fig. 1;

Fig. 4 is a schematic detail view of the varies in the safe and in the armed positions.

Fig. 5 is a detail view of the propeller vane assembly;

Figs. 6 to i0 are taken on line -e of Fig. l, looking down, and show, respectively: Fig. G, the positions of several members when the bomb is unarmed; Fig. '7, when the parts have moved approximately half way to the armed position; Fig. 8, the armed position; Fig. 9, when moved substantially half way to the unarmed position; and Fig. 10, the unarmed position.

The frame E. of my fuse mechanism is mounted in the body t of the bomb that containsl the main explosive charge, a booster charge 'l surrounded by part of the main charge, and an ex'- plosive lead 3 extending from the booster charge to a location where it may be red by the detonator. Detonator holder is rotatably mounted in frame E and is retained therein by a stud it that extends into a groove H in the detonator holder. Gear housing member l2 is rotatable in the upper part of frame 5 wherein it is held a pin i3 that is engaged with groove lil and is adapted to be shea-red when the nose of the bomb impacts upon a target, to permit the ring pin l5 carried by member l2 to be driven against detonator It in its holder il, the deto-nator at that time being aligned with explosive lead 8.

internal gear Il is carried on a spindle it that is rotatable in member l2 and that has an eccentric pin i9 extending into a slot 2li in detonator holder lock 2l. This lock has laterally extending flanges 22 that ride in rabbets 23 formed in the sides of a cut-away portion in member l2 and a tab 2d that engages a slot in the .member 35 between vanes /l and lll.

Wall of frame 5 to lock members 9 and l2 against rotation with respect to it. The under side of the outer end of lock 2l is cut away as indicated at 2t' to clear lug 26 on member 9 when the lock is retracted, 4there being a slot 26' cut into lug 25 to receive the outer end of look 2l. A loop t5 depends from the bottom of member l2 and passes under member 2 l.

Secured to upper end of member l2 is a cupshaped cap 2 carrying an internal gear V2t that has a greater number of teeth than gear Il. A double pinion 29 has one set of teeth 35 to engage gear 28 and another set to mesh with gear l1; pinion ZS slides over the surface of disk 3l of gear il' and is rotatable on a pintle 32 eccentrically connected to a shaft t3 by crank 34, shaft 33 being journaled in capEl.

A substantially T-shaped bearing member 35 has its stem'secured to shaft 33 and has rotatable shafts 35 and 3'! retained in its `cross piece by screws 32?; with a spring 39 secured at one end to each of

shafts

35 and 31 and the other end of each spring attached to member S5 under tension that tends to hold the propeller varies 49 and il in the positions shown in Fig. 1, which are the same as the full line positions in Fig. 4. The radially inner edge of each of vanes lili and il moves in a cut-away portion of the end of the cross piece of member E5 between shoulders l2 and which shoulders serve as stops to limit the rotative movement of the vane with its shaft. Rotation `oi. shaft 33 before dropping the bomb is normally prevented by a pin dit that passes through the shaft and a portion of cap 2l in which the shaft Yis journaled, the arming wire 45 connected to pin it being secured to the bombing rack to withdraw pin Il@ when the bomb is released from the rack.

In Fig. 5 .is shown a `propeller vane assembly having concave-convex vanes at connected to The shape of these vanes it issuch that wind pressurevacting transversely of the axis of the bomb body, regardless of direction, wl always tend to turn shaft 33 to move the fuse elements into the unarmed position, as will be presently explained.

The pitch of vanes #it and Gl is in such a sense that when in the position shown in Fig. 1, that is, the safe position or" lFig. e, wind `pressure acting on the vanes in the direction of the longitudinal axis of the bomb will keep the fuse elements in the relative positions disclosed in Fig. l with the detonator It out of line with the rng pin l5 and the explosive lead 8. It will be noted further that the body of the detonator holder 9 is interposed between the firing pin and the lead 8, that lug 2B on the detonator holder bears against the lower face of member I2 and that the loop 25 on member I2 contacts the detonator holder 9, thus preventing any motion of member I2 toward detonator holder 9 and eliminating the possibility of firing pin I5 reaching lead 8.

When the vanes d() and il are subjected to wind pressure of suiicient magnitude, they turn their

shafts

36 and 31 against the constraint of springs 39 and move to the armed position of Fig. 4. It is apparent that in this position the torque exerted on shaft 33 is in the opposite angular sense to the couple developed by the vanes in the safe position.

When the vanes are in the armed position and safety pin I4 has been withdrawn, shaft 33 will be driven in the clockwise sense and will, through cra-nk 36 and pin 32, slide pinion 29 around bodily in the same sense. However, due to the engagement of the teeth 39 on the pinion with internal gear 29, the pinion will be rotated in the counter-clockwise sense due to the fact that the gear 28 is locked to frame 5 by lock 2l. Internal gear I'I will be driven in the same sense as pinion 29 by the teeth 3| on pinion 29 since the number of teeth in gear I'I is less than the number in gear 28. For example, if there are two teeth fewer in the former than in the latter, gear I'I will be rotated only the angular distance between two teeth of gear II each time shaft 33 makes a revolution, which delays the arming of the fuse. Continued rotation of gear I'I and of spindle I8 connected thereto will cause eccentric pin I9 to withdraw lock 2I from the recess in frame 5 and abut the rear end of the lock against the closed end of the cut-away portion in member I2 in which the lock slides and thus locks the parts together so that pinion 29, member I2 and detonator holder 9 rotate as a unit with shaft 33 and vanes 40 and 4I. In this position the spring detent 48 in member I2 will engage depression 69 in lock 2l and thus form a connection between member I2 and lock 2l to return the mechanism to the locked position when the fuse is being unarmed, as will be hereinafter described.

After lock 2! has been drawn back it clears the lug 26 on detonator holder 9 and permits member I2 to rotate independently of the detonator holder, which continues until firing pin I5 is positioned above detonator I9 and lug 50 on member I2 engages the lug 29 (Fig. 7), when the detonator holder 9 is constrained to rotate with member I2 until lug 26 contacts stop 5I fixed to fuse body 5. This prevents further rotation of the parts and stops the mechanism with the detonator I6 aligned with lead 8 and firing pin I5 (Fig. 8). In this position, lug 26 can move into cut-out portion 52 in member I2, loop 25 on member I2 can pass into the cut-out portion 53 in detonator holder 9 and recess 5l! in detcnator holder 9 is aligned with lug 59 to permit lug 59 to be moved downwardly. With the parts in these positions, upon impact of the nose of the bomb, the member I2 will shear pin I3 and ring pin I5 will be driven into detonator I 5 to explode the charge of the bomb.

If safety pin 44 is removed while the bomb is on an aircraft in flight, the wind caused by the high speed of the craft would arm the fuse, in which condition it would be very dangerous for the craft to land. The present invention prevents such a contingency by causing the fuse to unarm at the slower speeds of landing. When the craft slows down preparatory to landing, the wind pressure on vanes 49 and 4I becomes insufficient to hold

shafts

36 and 31 turned to the arming position against the tension of springs 39 and the vanes are moved to the safe position. The wind then drives the vanes to turn shaft 33 in the counterclockwise sense which moves pinion 29 bodily in the same sense but the rotation of the pinion on pin 32 is in the opposite sense. The rotation of gear I'I is in the same direction as that of pinion 29 and therefore spindle I8 and eccentric pin I9 will be made to turn in the same direction and thus, through lock ZI, member I2 is given a clockwise rotation, longitudinal movement of locking member ZI being prevented by engagement of plunger 48 in depresson 99. Movement of member I2 brings lug 59 on member I2 against lug 55 on the detonator holder 9 (lug 59 is shown approaching lug 55, Fig. 9) and the detonator holder then turns with member I2 until lug 55 contacts stop 5! (Fig. 10), which prevents further movement of the members 9 and I 2. The detonator I6 has now been turned out of line with lead 8 and detonator holder 9 is interposed between firing pin I5 and lead 8. After members 9 and I2 have ceased to turn, shaft I8 rotates until eccentric pin I9 has slid lock 2l out into the locking position, the contact of lug 55 against stop 5I providing the necessary reaction to cause plunger 48 to be disengaged from depression 49; all parts are then locked and movement of the parts is stopped.

It is to be understood that the above description and accompanying drawings comprehend only the general and preferred embodiments of my invention and that various changes may be made therein within the scope of the appended claims without sacrificing any of the advantages of this invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

I claim:

l. In a fuse, a body member having a transverse partition therein, there being a hole through said partition, a detonator holder rotatably mounted at one side of said partition, said holder having a recess opening on the side thereof opposite said partition and a hole therethrough adapted to be brought into registry with the hole in said partition, a lug on said holder adjacent the hole therein having a slot in its free end, a member slidably and rotatably mounted in said body, shearable means normally acting to prevent sliding movement of said member, a lug extending from said member toward said detonator holder to engage said lug on the holder to move said holder to align the hole therein with the hole in said partition, a firing pin positioned on said member to be aligned with both said holes when said holes are aligned, a fixed lug on said body to engage said lug on the holder and stop the holder when said holes are aligned as aforesaid, a second lug on said holder engageable with the lug on said member to move said holder to the position in which said holes are not aligned, a locking element slidably mounted in said member to engage said slotted lug and said body in one relaative position of these parts and having a transverse slot therein and a depression in its outer surface, a loop depending from said member and passing under said element to contact said detonator holder except when disposed over the recess in said holder, a spring pressed plunger `in said member adapted to engage said depression when said element is in the unlocked position, a shaft journaled in said member, aneccentric pin projecting from said shaft into the slot in said element, a first internal gear having a disk body mounted on said shaft, a second internal gear having a slightly greater number of teeth than the first internal gear connected to said member and disposed adjacent said first internal gear,

a pinion disposed to be slidable on the body of said first internal gear and having two sets of `gear teeth each of which sets of teeth is engaged `with one of said internal gears, a shaft rotatably `mounted in said second internal gear, a crank including a crank arm and a pin journaled in said pinion and connected by the crank `arm to the last mentioned shaft, a T-shaped member `having the stem thereof fixed to the last mentioned shaft, a vane shaft journaled in each end of the head of said T member, a propeller vane `secured to the outer end of each of said vane shafts, said head having stops to limit the rotation of said vane shafts and resilient means normally holding said vanes directed outwardly from a bomb by which said fuse is carried.

2. In a fuse, a body member having in it a passage to contain an explosive lead to an explosive charge, a detonator holder rotatably mounted in said body and having in it a passage to receive a `detonator adapted to be moved into alignment with the passage in said body when said fuse is armed, a member rotatably and slidably mounted in said body, means to prevent sliding movement of said member except when in the armed position, a firing pin carried by said member adapted to be moved into alignment With said detonator and said lead in the armed position, a lug on said member extending toward said holder, a first lugon said holder engageable by the lug on said member to move said holder into the armed position and a second lug onsaid holder engage-- able by the lug on said member to move said holder to the unarmed position, a fixed lug to stop movement of said holder when in either the fully armed or fully unarmed position, slidabie locking means to lock said holder and said member to said body in the fully unarmed position, a first internal gear rcarried by said member, a second internal gear having a slightly smaller number of teeth than said first gear disposed adjacent thereto, means connected to said second gear to slide said locking means and to rotate said member, a bodily movable pinion having -tWo sets of gear teeth whereof one is meshed With each of said internal gears, rotatable shaft carried by said first gear, eccentric means connecting said shaft with said pinion, journal means connected to said shaft, vane shafts rotatably mounted in said journal means, a propeller vane mounted on each of said vane shafts, stops on said journal means to limit the rotation of said vane shafts and resilient means acting upon said vane shafts to hold said vanes normally in one position.

3. In a fuse, elements including a firing pin movable to and from the armed and unarmed positions, a first internal gear operatively connected to said elements, a second internal gear disposed adjacent thereto, said second gear having a slightly greater number of teeth than said rst gear, a bodily movable pinion having a separate set of gear teeth meshed with each of said gears, a pin rotatable in said pinion, a rotatable shaft, a crank connecting said pin and said shaft,

a T-shaped member having its stem xed on said shaft, two vane shafts rotatably mounted in the head of said member, a propeller vane on each of said vane shafts, a spring connected to each of said shafts normally to hold said vanes in such position that they Will tend to move said elements to the unarmed position but adapted to yield at Wind pressures above a predetermined minimum to permit the direction of pitch of said vanes to change to move said elements to the armed position and stops carried by the head of said member to limit the rotation of said vane shafts.

4.. In a fuse, elements including a firing pin movable to and from the armed and unarmed positions, a first internal gear operatively connected to said elements, a second internal gear disposed adjacent thereto, said second gear having a slightly greater number of teeth than said first gear, a bodily movable pinion having a separate set of gear teeth meshed with each of said gears, a pin rotatable in said pinion, a rotatable shaft, a crank connecting said pin and said shaft, a T-shaped member having its stem fixed on said shaft, two vane shafts rotatably mounted in the head of said member, a propeller vane on each of said vane shafts, a spring connected to each of said shafts normally to hold said vanes in such position that they Will tend to move said elements to the unarmed position but adapted to yield at Wind pressures above a predetermined minimum to permit the direction of pitch of said vanes to change to move said elements to the armed position, Stops carried by the head of said member to limit the rotation of said vane shafts and means to lock all of said elements together to move as a unit from or toward the unarmed position and to lock said elements against movement when in the unarmed position.

5. In a fuse, elements including a firing pin movable to and from the armed and unarmed positions, a first internal gear operatively connected to said elements, a second internal gear disposed adjacent thereto, said second gear having a slightly greater number of teeth than said first gear, a bodilf,T movable pinion having a separate set of gear teeth 'me-shed with each of said gears, a pin rotatable in said pinion, a rotatable shaft, a crank connecting said pin and said shaft, a T-shaped member having its stem fixed on said shaft, two vane shafts rotatably mounted in the head of said member, a propeller vane on each of said vane shafts, a spring connected to each of said shafts normally to hold said va-nes in such position that they will tend to move said elements to the unarmed position but adapted to yield at wind pressures above a predetermined minimum to permit the direction of pitch of said vanes to change to move said elements to the armed position, stops carried by the head of said member to limit the rotation of said vane shafts, means to lock all of said elements together to move as a unit from or toward the unarmed position and to lock said elements against movement in the unarmedposition and concave vanes mounted on said member on opposite sides thereof oriented to move said elements always 'toward the unarmed position when acted upon by Wind ressure transversely to the axis of a bomb by which the fuse is carried.

6. In a fuse, elements including a Vfiring pin movable -to and from the armed andA unarmed positions, a first internal gear operatively connected to said elements, a second internal gear disposed adjacent thereto, said second gear having a slightly greater number of teeth than said rst gear, a bodily movable pinion having a separate set of gear teeth meshed with each of said gears, a pin rotatable in said pinion, a rotatable shaft, a crank connecting said pin and said shaft, a T-shaped member having its stem xed on said shaft, two vane shafts rotatably mounted in the head of said member, a propeller vane on each of said vane shafts, a spring connected to each of said shafts normally to hold said vanes in such position that they will tend to move said elements to the unarmed position but adapted to yield at wind pressures above a predeermined minimum to permit the direction of pitch of said vanes to change to move said elements to the armed position, stops carried by the head of said member to limit the rotation of said vane shafts and concave vanes mounted on said member on opposite sides thereof oriented to move said ele ments always toward the unarmed position when acted upon by wind pressure transversely to the axis of a bomb by which the fuse is carried.

'7. In a fuse, elements movable to and from the armed and unarmed positions and means so to move said elements including propeller vanes adapted to be set with their direction of pitch such that wind pressure below a predetermined value on said vanes tends to move said elements to the unarmed position and to change said direc tion of pitch to tend to move said elements to the armed position when said pressure is above said predetermined value and resilient means tending to move said vanes to the rst mentioned direction of pitch.

8. In a fuse, elements movable to and from the armed and unarmed positions, means so to move said elements including propeller vanes adapted to be set with their direction of pitch such that wind pressure below a predetermined value on said vanes tends to move said elements to the un armed position and to change said direction of pitch to tend to move said elements to the armed position when said pressure is above said predetermined value, means tending to move said vanes to the first mentioned direction of pitch andvother vanes associated with the aforesaid vanes adapted always to move said elements to the unarmed position when acted upon by wind pressure transversely to the axis ci a bomb by which the fuse is carried.

9. In a fuse, elements movable to and from the armed and unarmed positions, means including differentially acting gears to move said elements to delay the movement of said elements, a rotatable shaft operatively connected to said gears, a T-shaped member having its stem fixed on said shaft, two vane shafts rotatably mounted in the head of said member, a propeller vane on each oi said vane shafts, a spring connected to each of said shafts normally to hold said vanes in such position that they will tend to move said elements to the unarmed position but adapted to yield at wind pressures above a predetermined minimum to permit the direction of pitch of said vanes to change to move said elements to the unarmed position and stops carried by the head of said member to limit the rotation of said Vane shafts.

10. In a fuse, elements movable to and from the armed and unarmed positions, means so to move said elements including differentially acting gears operatively connected to said elements, a rotatable shaft connected to said gears, propeller vanes connected to said shaft, said vanes normally having a direction of pitch that will cause said vanes to move said elements to the unarmed position but movable to a direction of pitch that will cause said vanes to move said elements to the armed position and means tending to hold said vanes with the rst mentioned direction of pitch.

11. In a fuse, elements movable to and from the armed and unarmed positions, means actuatable by wind pressure to move said elements toward the unarmed position when said pressure is below a, predetermined value and toward the armed position when said pressure is greater than said value and other means tending always to move said elements toward the unarmed position when acted upon by wind pressure transversely to the axis of a bomb by which the fuse is carried.

12. In a fuse, a propeller having elements adapted to have a pitch direction to unarm the fuse when acted upon by wind pressures below a predetermined value and to move to a pitch direction to arm said fuse when said pressures are greater than said Value and other elements tending always to unarm said fuse when acted upon by wind pressures transversely to the axis of a bomb by which the fuse is carried.

13. In a fuse, a propeller having elements adapted to have a pitch direction to unarm the fuse when acted upon by wind pressures below a predetermined value and to move to a pitch direction to arm said fuse when said pressures are greater than the said value.

14. In a fuse, a propeller having elements adapted to have a pitch direction to unarm the fuse when acted upon by wind pressures below a predetermined value and to move to a pitch direction to arm said fuse when said pressures are greater than the said value, other elements tending always to unarm said fuse when acted upon by wind pressures transversely to the axis of a bomb by which the fuse is carried and means actuated by said propeller to delay the arming or unarming of said fuse.

15. In mechanism for arming and unarming a bomb fuse, a propeller operatively connected to actuate the mechanism, said propeller including blades mounted for limited rotation about an edge of each, means biasing said blades to one position wherein air pressure of less than a predetermined magnitude thereon actuates the mechanism to the unarmed position but blades are moved in opposition to the biasing means to the armed position by air pressure above said magnitude, and curved blades tending always to move said mechanism to the unarmed position when acted upon by air pressures across the aXis of the propeller.

PI-IILIAS H. GIROUARD.

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

UNITED STATES PATENTS Number Name