US2434971A

US2434971A - Fuse

Info

Publication number: US2434971A
Application number: US436817A
Authority: US
Inventors: Wilfred E Thibodeau
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-03-30
Filing date: 1942-03-30
Publication date: 1948-01-27
Anticipated expiration: 1965-01-27

Description

Jan. 27, 1948.

W. E THIBODEAU FUSE Filed March 30; 1942 4 Sheets-Sheet 1 all: map

Jan. 27, 1948. w. E. THIBODEAU FUSE 4 Sheets-Sheet 2 Filed March so, 1942' Wilfre :1 E. Thihu deuu Jan 27, 1948. w, E, THIBODEAU 2,434,971

FUSE

Filed March 30, 1942 4 Sheets-Sheet 3 III w,

Jan. 27, 1948. w. E. THIBODEAU FUSE 4 Sheets-Sheet 4 Filed March 30, 1942 qr WW Wilfped E- Thihu deuu Patented Jan. 27, 1948 UN IT ED ST PATENT OFFICE.

19' Claiins.

(CTLIOZZ-JH.)

(Granted linden the act March 3;. I883; as: amendedAprilififl, 192 $3370: 0..GL..757)

The invention described herein may be manufactured and'usedby'or for-the Government for overnmental purposes; without the paymentto me or any-royalty thereon:

This invention pertains to 'a mechanical movement, to its'application in afuse and-morepar ticularly in a fuse-fora rotating-projectile.

An object of this invention: is to provide a mechanical movementwherein a member is constrained to rotate about the path" of recession of arr opposed pair" of: centrifugal weight members.

Another object" of the invention is, to provide a fuse arrangement which, is; applicable for use inprojectiles havin g high .or-relatively lowspeeds of rotation:

A further object of the invention is-to'provide a. fuse having. centrifugalmembers" so connected tothe firingmechanism"thatnocentrifugar member can: move to" armed position; without similar movement oftheother:

An important object of this invention is to pro vide a fuse-which wilrbearmedonly'when, a predetermined speed of rotation is reached thereby promoting bore safety;

An additionalobject ofitheinventi'on is to pro vide a. fuse having centrifugal: members'which are armed without the use of? extraneous. safety devices.

A still further object ofthe invention is to providea' fuse of the floating-pin typewoperating on the centrifugal principle.

One of the. principal objects of" the invention is to provide a' fusewhi'ch is simple in construction, inexpensive to manufacture of a, design adapted; to mass production methods, reliable 35 in its operation, and safe in handling.

To these and'other ends theinventi'on consists in the construction, arrangement andcombinationof elements described hereinafter andpointed out in the claims; forming a. part ofitllis. specifi'cation.

A vpractical. embodiment of. theinvention is 11- liistratedini the accompanyinadrawing wherein:

Fig. 1. is-anelevational-view with. parts inisection; of theefrontt end of; aprojectile showing one typeeof fuse mounteditherein;

Fig.- 2 is; a. sectional; views on; the line; 2-2' of Fig; 1',

Fig. 3 is; a: top: plan. view; of? the projectile delineatedin Fig.1,

Big. 4: is a; sectionalivieveonithedine 44 of Fig. 1, r

Eig. 5. is .anenlargedz fragmentary: view'in perspectiveioficertaim offthesfuse components;

Fig: 6-is a view -insideelevation of 'the sealing cap of Figured;

Fig. 7 is a fragmentaryviewshowingone manner of mounting a firingpin and-hammer'ilr a fuse=element,

Fig. 8 is a fragmentarysectional view*representinganother manner of mounting" a fuse in a-sliell;

Fig. 9 isra seetional viewat the nose ofash'ell which contains a modified-- fuse structure;

Fig. 16 is a;- sectional View on the line Hl"l'll of Fig;

Figs I1 is a partial'sectional view of thefront end of at proiectil'e' which the-fuse structure is secured within a sealing cap;

12 is asectional view-on the-1ine-l2l2 of Fig: 11

Fig. 13 i's'a transverse sectionalviewatthe-nose action,

Fig: 14-is-za similar-view of a modified structure,

Fig 151s an el'evational-view of the-sealing cap which; supports the-fuserepresented inFig; 14,

Fig: Iii-is a: transverse secti'onal View through 25 the nose end of a' shell" showing another fuse structure;

Fig. PI is: a; perspective view of the combined cap and component of Fig. 16* wh-iehaotuates the firing pin,

Fig. 18 is a;longitudinalseetional viewthrough the nose end oi v a; proj'eetiledelineating a modified fuse;

Fig; 19* is alseeti'onai view onthe.=1ine|9i9 of Figs. 18,

Fig. 20 is=a longitudinal sectional view of-an additional modification,

Fig: 22 is: a transverse sectional view on the line 2 l-Zl of Fig. 20, and.

Figs. 22-'-Z6'= areseeticnal views of other" fuse 40 organizations; Fig. 25- loeing atransverse section on thelineiF-fi of- Fi'g: 24%

Fig 2 an elevationafview with parts in section of the nose end" of a: projectile showing anothen modification of the invention;-

Fig:- 28 is=amelevationa1 viewof the cap which within the-cavity at the noseend of the'projeetfleshown-inFig. 27;

Fig: 29 is" atransverse section on the line m ze of Fig; 27

30- is -a= cross-section" ofthe cap shown in Fig? 2'7; in=a plane-passingthrough the center'of the cap and at right angles tothe sectional plane of Fig. 2'7

Hef'errine'td- 1"-6,* there is showna por- 55 tiomofi the-body- F of-a shell containing acharge endota projectile showing a-fuse having-a snap I 3 2 of high explosive and a primer cup 3 which is held within a bore 4 which communicates with the charge 2. The nose of the projectile is provided with a pair of concentric communicating recesses 5 and 6 which are of unequal diameters. Recess 5 has a larger diameter thereby providing an annular seat or step 1. Within this step and the body .is a pair of diametrically disposed grooves 8 which are arranged to receive a pair of pins 9 that pass through the extended ends Ifl--Ii] of an elliptically shaped ring II. Ring I I is preferably a light metallic band which has a width several times its thickness for reasons which will be subsequently stated. The ring is disposed so that its width lies in a plane which is substantially parallel to the longitudinal axis of the shell. Spaced equidistantly about the ring and secured thereto are several weights I2 which may conveniently be rivets. A pair of vertically elongated rectangular ,holes I3-I3 (Figure 5) is provided on diametrically opposite positions in the ring. These are arranged to receive a transverse bar I4 which carries centrally disposed jacent its ends I6--I6 with 90 helical twists III'I which are more clearly illustrated in Fig. 5. The twists are imparted in opposite directions so that when the coacting portions of the ring II simultaneously move outwardly the transverse bar I4 is rotated 90 and the firing pin is rocked to a position where its axis is vertical.

The pins 9 support ring II so that it is suspended in recesses 5 and 6. The bottom edge of the band is preferably spaced a very small distance from the bottom I8 of recess 6. Inserted in the recess 5 is a cup-shaped sealing cap I9 which is provided with a pair of slots 20 and a pair of lugs 2| which overlie the pins 9, the latter being seated in the pair of grooves 8 in the shell body. The lugs 2| hold the cap I9 against rotation relative to the shell body I and as a consequence prevent binding between the walls of slots 20 and pins 9 when the projectile is subjected to rotational forces. Cap I9 is secured in place by peaning over the outer circular edge .22 at the nose of the projectile. Thelength of the firing pin maybe such that the point will just graze the primer in arming.

Fig. 7 shows a conical firing pin I5 having a reduced shank 23 which is press fitted in a hole I4 due to friction with the floor of the fuse cavity.

After the projectile has left the gun and when a predetermined speed of rotation has been at-- tained, centrifugal force is sufficient to urge the weights I2 outwardly away from the axis of rotation. These weights are provided to overbalance the effect of pins 9, but the band I I may be so designed as to incorporate a weighted portion integrally. The effect is to distort the ring II from an oval shape toward or beyond the circular form. This pulls the reduced ends I0 and the associated pins 9 inwardly in the grooves 8. Simultaneously the rectangular holes l3 coact 4 with the twists I! on the transverse bar to rotate it 90 thereby presenting the firing pin I5 in armed position in direct alignment with the center of the primer 3. The firing pin cannot be rocked beyond the unarmed position because of the 90 bends in the bar I4. When a target is struck, the cap I9 is pushed or crushed inwardly into engagement with the tubular cap or hammer 25 on the end of the firing pin and the pin is thrust into the primer thereby exploding the shell in the usual manner. In this modification,

only a sharp thrust into the center of the cap will be effective since the ring II will, to some extent, resist deformation of the cap in the outer portions. Other modifications herein provide for more sensitive percussion.

It will be understood that other additional safeguards against spreading of the hoop while in the gun may be provided in various manners forces,

well known in the artjif such be deemed necessary.

A particular feature of the invention is the position of the transverse bar It when the fuse is in the unarmed position. As shown in Fig. 5 the width of the bar lies in a plane which will resist bending at all times prior to firing and while the spinning projectile is being accelerated from the gun and before the effect of centrifugal force is sufficiently pronounced to overcome other forces and rotate the bar. When the firing pin is in the armed position, the transverse arm II can be readily bent axially of the projectile as a result of impact when the shell strikes its objective. The width of the bar is great While the thickness is small, thereby permitting the use of inexpensive fiat stock which is easily and quickly formed into the necessary fuse elements, although this invention is not limited to fiat .stock or any particular screw mechanism for turning the firing pin. Furthermore, the effect of inertia during acceleration on the bar I4 creates sufficient friction between its lower edge and the slot I3 whereby spreading of the band II is prevented until cessation of the setback whereupon the clearance is restored. This promotes bore safety.

The pitch of the twist II constitutes one factor having a bearing on the ease of the expanding movement of the band and can be utilized to determine the velocity of rotation necessary to arm the firing pin. It may be perceived that structures other than a slotted hoop and bar, for instance, those provided with threaded or other cooperating helical elements can be employed to accomplish the same result. However, the band organization is a preferred arrangement because of the obvious saving in time, material, and machinery involved in the manufacture, and due to the safety factor involved in utilizing a member affording a greater resistance to bending in one lateral dimension than in the other.

A slight clearance exists between the bottom edge of ring II and the base I8 of recess 6 to avoid any drag or friction therebetween which would hinder the expanding movement at the smaller diameter of the oval ring after setback forces have ceased and centrifuging commences. The primer 3 need have but a small opening beneath the firing pin to receive it when it is thrust back upon impact of the shell with the target. This will serve to prevent premature ignition by accidental hits near the gun.

While the fuse is illustrated as a nose fuse the same structure can be employed in a base anchors 5'. deto iatine: hi a. o tact to a ign a corn.- oonent. t Woo oi mechanica fus coastin ring; nd bar organ Ration 121i Ides ex me; safety d n the e; t the; maj r: .1 qare e s or ma ci us l W lli not. d tonate e d vi he. two hal es. ofthe hand must move in opposite directions from the 1onitudinalaais ofrthashell; to arm the fuse. This is. an; outstanding.- feature, of they device since, if the; sh 1l= isiarred... one. arm: will move out, but the. other will: moveinv the .same. direction and restraint the bar from turning; Th p o actionof thepartsto armthe fuse is impossible except, byj centrifuging... Since: safety during manufacture is a. factory whichv must: be. considered; the use ofr a. pair of; diametrically disposed grooves 8: to receive the ring sustaining pins 9 is.- an important: feature. This enables the ring supportedfiring pin organizationto e slipped downintoitherecesses: Sand: 6 from the nose of the:- shell! without twisting the firing pin l so as to. come. into registration with the'primer cup 3: This avoids fortuitous explosions during assembling operations. 7

Fig; 8" illustrates abandstructure similar to Fig. 4 inwhich a pair of diametrically disposed holes 26 are bored into the body! of the shell to receive the pins '9. The sealingcap I9 is simply a cup-shaped member without any projecting lugs. Care mustibeexercisedin mounting this fuse so that the firing pin does not come into engagement with the primer, when the ring is fleieed topresent the pins to-the holes.

Figs 9 and'- 10 represent a modified fuse organization in;- whichthe pins 9- are secured at two: points" onthe smaller diameter of the oval ringl t. .T he more-remote ends Ill-of the ring engage-theflat ends 16 that are disposed outsidofthe helica1=twists- IT; The pins S'bear against compression springs zlwhichare seated in a pair of bores 28 in the-shell body and center-thawing H; These and'similar centering dev-ices-;may"also be used in the other modifications; or the-primer;- face may be made of sueh-si-zeas tounderlie the-pin for any position thereof due to-slight-sidewise excursions of the hoop: In; particulan thehoop may be steadied in its la ycentral position by mounting the twishbalj in'tlfie shell with pins as in. the modifieatienof Figures lh and' 19; Centrifugal force causes-the;pins 9*whicl 1 act as weights to fiy outwardly against theresistance of the springs 21. This bonds the ring; into a somewhat circular shape and the coacting rectangular holes [3' and thetwists-Ihrotate the transverse bar [4 through 90"toar-m*the fuse; This arrangement is easily and comparatively-safely mounted in a projectile since-the;required-'flexure-will-not rotate the bar. A disle- [9' serves as a sealing cap and is held. in positionbytheusual peaning operation, or similar eitective means;

In Figs; 11- and 1'2-t-her.e is shown a reliable, practicalembodimentoi'the invention. Apair of Ll sha-ped bands-29w are secured at their bends 39 to the inner -wall;of-the cup-shaped sealing member Why a pair of fasteners such as, set screws 31". 'Thefreeends orarrns 32 are provided with the Q J 'Qwhichengage the transverse bar I4 inside ofthe helical twists I}. Corresponding arms on,each bandfi e in contiguous relation- 1 eent re. cen r gal structure. is con- VQHiQ ill? .19. .Q. 1 he. cup 19. which is easily and" without danger first fully. assembled, and

. thenwinserted inthe. recessi 113i theshell; The sealing member l9 isof suitablediameter to. slide ree y; in. the; recess. 5. The. depth of: recess 5 is somewhat greater than the skirt. portion of the a sealing member: I9; and; has a. centrally disnosed cylindrical protuberance 33 in: its: base Which contains the primer 3. Thadlameter of the-protuberance 33 is somewhat: greater thanthespan of the arms 3.2: of the bandslfl when the structure; is in thoinoperative'or unarmed position; as shownin. Fig; 12.. When. the shell: is: firedthe arms fly outwardly; rotating; the firing pin to: arm it, and'reaehv a, position free ofthe protuberance 3.3., This enables theucup to slide; downwardly into the recess 5 when the projectileistrikesaits objective and. carry with it the firing. pin. This structure ismore sensitiveon impact in that it is not; necessary that thesealing member. [.Q be bent inwardly on. impact. to. displacethe; firing p nv axially and detonate. the; shell. This; pros vision for movement of the capmay be; madezin the. other modifications also. In. modifications where thecentrifugakunits are fixed, there is .no danger of falling. ofi'center, but it will be under: stood that the full hoop with slidablepins engage ing the cap may alsobe used'in theFigure 12 type.

7 It will-be noted-that. slots 13min the bandsifi must be, made somewhat wider than the slots ["3 in Figure 5. because inthis case the bands move relative to one anotherand clearance mustrbe provided to prevent binding: Thebindingeffect may also be obviated by providing. only. very small pitch to the bar twist so that it. w-ill'function on a small travel of the centrifugal mem.- bers. The latter, in suchcase may be made more resistant to deformation.

Fig. 13 represents a fusehavingasnap-action. A ring II is conditioned witha pair of oppositely disposed and: inwardly. directed bent bows 3'4. When suffioient speed of rotationis.attainedithe bows 34 belly outwardly withasnap action and arm the device. This ring',.because of. itsparticular configuration and properties, willmaintain the shell'in an armedconditioneven though the velocity of rotation decreases torthepoint Where a fuse built in accordance with the other modifications would havebecome unarmedby ro tating back to its original position as a' result of decreased centrifugal force, The structure shown in Fig. 13 possesses added bore safety since it arms at. rotational speedsswhich may-be adjusted to anicety.

Fig. 14 delineatesa snapaction fuse whi'chis provided with a pair ofspacedbars 35which engage the transverse bar I5; Each arm has an inwardly bent bow 34 and the ends ofithese arms are fixedly. anchoredin spaced slots '36 in the skirt portion of the sealingcap l9; This provides an integral fuse structure which is readily inserted in the recess 5 in the shell-in theusual manner although it will be understood that bars 35' may be attached in the projectile itself. Thes-paoed bars employed in this modification are easier and cheaper to fabricate than the ring structures-pr eviously illustrated.

There is. Shown in ig. 16 a sectional view-of a projectileincorporating the modifiedarrangement of Fig. 17. Here thering I la is'a part of the cap itself, and'has a pair ofdiametrically opposite L-shaped cuts 31 made therein so as to permit the formation of' two parallel flat wings 33. These wings have: freeends-3'9 which" lie against the shoulders 40. formed in cutting-the Opposed rectangular holesl3 cut' in L cuts;

these wings sustain the transverse bar I 4'which carries the firing pin I5. The cap organization is mounted in the shell as shown in' Fig. 16 with the bowed portions designated generally as M in contact with the cylindrical walls of the recess 5 and the free ends 39 of the wings 38 extending into a pair of spaced slots 42 in the shell body. The entrances 43 to these slots are flared outwardly on but one side of each slot. When the shell attains a predetermined velocity of rotation the wings 38 belly outwardly and through the intermediation of the slots I3 and the helical twists II arm the device. The enlarged entrances 43 to slots 42 facilitate the outward movement of the wings 38.

The simplicity of the Figure 16 modification will at once be apparent. Other than the cap usual in this type of projectile, the only separate part is the bar carrying the firing pin. The essential fuse structure is embodied in simple stamping operation performed on the cap and a twist of the firing pin bar. It will be understood that although a cap member is shown in Figure 16, a simple ring member of similar construction but without the top covering may also be employed separately in a projectile in place of the hoop members shown in other modifications. Likewise, by simple mechanical expedients, provision may be made to prevent return of the ends 39 into the slots 42 if it is desired to maintain the fuse armed after missing a target so as to be self-destroying. Wings 38 may be weighted to aid centrifuging.

It has also been contemplated that the wings 38 be cut somewhat shorter than is illustrated. In this case there would be no need for the slots 42 in the shell body since thefree ends of the wings would not extend outside the ring Ha. This modification would arm under less force than that of wings 38 as shown. However, in such case the bar will move slightly in a horizontal plane, and account must be taken of this in locating the pin with respect to the primer.

Figs. 18 and 19 illustrate a modification in which the fuse components are mounted as a unit in the sealing cap or cup I9. The transverse bar I4 has its ends I5-I6 riveted to or simply pinched in a pair of slots in pins 44 which are journalled in apertures 45 in the cap I9. A pair of telescoping U-shaped members 45 form the flyweights for the device. These are conditioned in the usual manner to engage the transverse bar I4 and are pulled outwardly by centrifugal force to engage the twists I7 and arm the fuse. The telescopic arrangement insures translational movement of the two bands 46 without binding with the bar.

In the structure represented in Figs. 20 and 21 the ring II is provided with a horizontal slot I3 which receives the transverse bar I4 which rests in a horizontal plane when the device is unarmed. This arrangement permits the use of a narrow band for ring II and hence a shallower recess 5. The firing pin I5 is a projection which is integral with and in the plane of the bar and was formed when the blank or bar was fabricated by a stamping operation. A notch 41 appears in the transverse bar and constitutes a weakened portion so as to enable the bar to be more easily deformed or bowed inwardly in its armed position when the shell strikes its objective. It will be noted that the provision of a firing pin on the side of the bar permitsthe horizontal positioning of the bar in the unarmed position and the use of a circumferentially extending slot in the band. Thus, the band may be made much narrower than the bar with the result that upon arming, the central portion of the bar will extend above the band and will be accessible to shocks on the cap prior to contact between the cap and the band, which contact would tend to form a barrier against flexing motion of the cap.

Themodification shown in Fig. 22 has a, pair of wings 48' which are formed by cutting two pairs of parallel slits in the top of 'a cup-shaped sealing cap I9 and bending them downwardly and perpendicular to the top of the cap. These wings are provided with the usual vertically disposed rectangular slots I3 which support the transverse bar I4. Centrifugal force urges these wings 43 outwardly and arms the fuse. The end portions I6 of the transverse bar are provided with shoulder stops 4!]. which are conveniently formed by bending the ends I6 into a right angle. These stops keep the wings 48 from'escaping the'ban' Similar stops, if desired, can be used on any of the devices illustrated. A sealing disk I9 is preferably employed to render the mechanism weatherproof. The entire cap unt including the firing pin shown in this embodiment is arranged to slide farther into recess 5 to. actuate the primer when the wings 48 and the transverse bar I4 are in the armed position. The usual hammer 25 (e. g. see Figs. 1 and 5) may be provided to afford contacting relation between cap and firing pin when armed.

Fig. 23 shows a fuse similar to that of Fig. 22.

A cup-shaped sealing cap I9 is provided with a centrally disposed hammer 50, The wings 48 are separate members and are secured within the cup or cap I9 by suitable means such as rivets 5|. The whole cap structure does not have movement in the recess 5 on impact as does the fuse arrangement of Fig. 20. The firing thrust is obtained by movement of the hammer 50 when the top of the cap I9 is bent inwardly.

The fuses represented in Figs. 24-26 are characterized by their ability' to operate at lower speeds of rotation. The sealingcap I9 of Fig. 24 includes an elongated hammer 50 which is secured thereto in any convenient manner, A cylinder 52 with a flanged portion 53 i positioned in recess 6 and on the shoulder I of recess 5. Wings 48 are formed by slitting the cylinder longitudinally to any convenient length thereof as at 54. These support the transverse bar I4 in a manner previously described. Centrifugal force from rotation carries these members outwardly (as shown in phantom) and arms the fuse. The long leverage of these wings enables the fuse to be armed at relatively low speeds of rotation.

The fuse of Fig. 26 renders unnecessary the use of a hammer of the character shown in the preceding embodiment. The cylinder 52 and its wings 48 are formed in the previously described manner but the cylinder does not include the flange, This cylinder is mounted in an inverted position in the recess 6 as contrasted with the one in Fig. 25 and the wings 48 are directed inwardly. A cylinder of smaller diameter could be provided with the wings in normal position. Centrifugal force carries the wings 48 outwardly and rotates the transverse bar I4 to the firing position so that pin I5 is presented in alignment with the primer 3 which is supported in a cylindrical explosive container 53 that is threaded into the shell body I at the lower end of the recess 6. This fuse structure also features arming at lower speeds of rotation.

9,3. llt-zwillabe apparentstoioneiskillediimthe art-that anyl oflthe fusestructun-isldescribed: alcoves canlbej: easily; arranged? toisenvee as the? armingmeansliofi a time fiuser. While the modifications; shown are confinedi to al membencazrmying: a firingzpin: it Willa be readily appreciated tol those: skilled" imthe; art that any componentlot, anyimeohanioalzfuse malt be varied from: unarmeditlo:armempositionlbyn the mechanical: principle: embodiedl-in-zthisi invention; that is: tosan; azmemben notatedzinto positlombyr at twistingl actiom engendered! centrifugal; Weightsz.

The; invention; does: amayy thes needi for a-m extra setback. safety: ccmmnn. mostfuses: sincerit can onlylbeeoperatembyccentrlfugal; force; Due to the; interrelated:centrifugahmembere and: the=- nature! of: their? coactiom with the: turm bar, then 7 cannot: arm v ther fuse; by; independent: action: or unidirectional.= eficrta. There must be? a vergence. As fanas lfanrawarezthis issthefi'rst fusei having centrifugal: arming: members-1 which do: not: require extra? safety: elements; to holdithe centrifugal membenss sate position; which safety: elements: are mere-a impedimenta. and; 11ers.v fommno other function imthafuse, Furthermore, most: off-the known; saiety't elements: offierkat least a: possibility of accidental arming: due to mishandling, which is: obviated in", the fuse of this invention; one tori the employment of: thesnovel; principleofstheshelical membenoffopposite hands.

Figuresi2ll to; 3Dlshomastypm ofi fuse incorporate-- ing additional-i safety features: alluded: to hereinbefore: In thisamodiflcatibn theienw'tiite". hoopza-n'd twist-bar assembly is; resiliently mounted to; ale low-the twist bantosreeede intozaslot on. setback: asra further' bar to:rotatiomandithe said assemblw will also: recede on impact to: aid firings In. addition; both the hoop and twist-bar area-pinned; tolthezcap tolmaintaimtheinsylmnetrical and cenzetratalignment;

The re ilientv mounting: is afforded? by leaf springs 54; which maybe conveniently; attached to the can, engaging: under pinsrfion thezhoop. III:- and. under'pinsflih AsdiametralislhtfiE-intthe central boss 33 is: dimensioned to) receive;v the twist ban M2 on: setback. andi the; top. of? primers a is preferably: set: somewhat: below: the bottomof slot: 55l For the purpose; of: employingthe: safety slot. 551 the hoop: lzli im this casezclearathe -central' boss in themormalposition; 1

Due to: the unusual shapeof: the: caps shown, it may conveniently be moldedl of. plastics, al-. though othetsimplerl caps may also be used employing the setback safety shown.

An outs anding-featureof-theinvention is the ease of functioning, Incontradistinetion tosthe known mechanical fuses having moving parts; the amount of work involved in arming is surprisingly small: The moving part involved, that is, the twist bar does not, move against-v: parts other than-the slot inlthe hand; For alli'practieal purposes it is fioatingin, space; and merely; has to: turns ovenon its axis, to arm.. 'Bhlls itihasi the advantages; common to the sorcalleid supersensitiVe fuses, and, yet possesses inherent characteristics of certaintyan'd' safety. Furthermore its inertiaa can be still further-reduced by dimensioninga and theeuselof light'materials. Due: to the small, amount. of. work involved; the pitch: of the twist can .belmadewverysmalh andthus thelfimctioning: cam be. varied withlmwidealimitszadaptlng the principle to all calibers and velocities. In very small calibers a fuse according to the invention can be designed which would resemble the fine parts of a watch and yet be efiective.

Whereas;. in the; specification} and: claims the: connectiom between theroentri-fugal members and thebody tolberturned isvariouslyv referredto; and especially as a twistf-"it-will be understoodthat anv equivalent; mechanical connectionwhich will convert. the? translatorn motion; of the centrifugal membersiintmaturning motionofthefiring-parts, omamaxis-rdireotedlinthapath: of recessionof, the oentriiusal members; may be; used: and; is understuodito come withinl the: meaning of the word twist? 1 A, comprising: a barofrectangular sectiers twists of; opposite hand inr said bar, a hoop memben having: diametrically opposed openings slightly larger than the section of said barandreceiving: the? same, and a firingcomponent on said, her and extending transversely thereto;

Aifuseas inaclaimil; wherein thecross sect-ion ofisaitl bar is of unequal dimensions andsthe opera ingsin said hoop have'their long dimension at an: angle to the plane of thehoop;

31. A fuse as in claim 1 wherein the cross section, of said bar is of unequal dimensions and the. opjeningsin saidhoop have their long dimension; in, the plane of the hoop.

4. A fuse comprising a bar; of rectangular sectionj,. twists of opposite hand in saidlb'ar, a hoop member having diametrically opposed openings slightly larger thanthe section of said bar and receiving the same, a, firing component on said har'and extending transversely thereto, and dia-. metri al y opp sedme s on, id ho p-for gagement, with: the innfir walls of a projectile.

5.; Ina projectile having a nose opening, a fuse in said p ning co prising an. ell psoidal. ho n. iametrically pposed pins, on sa dho p on he line of the major axis thereof; slots in, the wall of. saidproie ct'i1e, said pins bei r ceive in said s10ts, a cap covering said opening and having ears in, said, slots. overlying said pins, diametrically. opposed? slots said hoop On the, line of. the minor axis thereof" and parallel to the axis of, the projectile, a bar received in said slots, twists of. opposite" handin. the. bar o tsi e said hoop. and v a firing. pin extending from said bar laterally of the projectile axis when the. fuse is in unarmed position with, the hoop inside the twists.

6 1n a fuse as in claim 5, weight members canrile fhyv said, hoop to, overbalance said. pins centrifugally.

7; In afuse as. inclaim 5,, a. hammer memberv on the side of" the bar Opposite the firing pin and, aligned therewith.

8:.In a projectile having. a nose, opening,, a closed bottom in. said? opening, a central pro.- tuberance. on. said bottom, a fuse comprising an ellipsoidal loop member. with, minor axis lying withi the. area of, the protuberance, a closure. capifbr, saiflj opening, spaced from the bottom. of said opening, said loop member engaging said capv at. the extremities ofgits, major axis, diametricall'y opposed slots in saidiloop member on, the lineof. its minor axis, a bar received in said'slots, twists of; opposed hand in said? bar. outside said l'oopnand afiring pin on said bar, extending there-- fromlaterally of. the projectile when in the unarmed. position. with; the. loop. inside the twistsinl the. said, ban

9. In a projectile having a nose opening, a fuse comprising a cap member for said opening, spaced cross members attached to said cap, mutually directed bights centrally of said cross members, slots in said bights, a bar receivedin said slots, twists of opposite hand in said bar outside said bights and a firing pin on said bar and extending laterally therefrom.

10. In combination, opposed centrifugal units, means constraining said units to a radial path of flight without rotation about the general line of said path, a cross member of oblong transverse section extending between said units, and spiral means of opposite hand on said member slidably received, respectively, in openings in said units, said openings being complementary to said spiral means whereby the member is turned about an axis in the generaldirection of the path of recession of the units upon centrifuging the latter.

11. In a projectile, a fuse comprising a firing component and a beam type carrying member having the said component fixed thereon, said carrying member having a high ratio of length to cross-sectional dimensions and a high ratio between the cross-sectional dimensions whereby fiexure is rendered more facile along one of the transverse directions of the carrying member than along the other, a second firing component in the projectile, means for mounting said carrying means with its direction of less facile fiexure aligned with the said second firing means, and means to adjust the carrying member to position where its direction of more facile fiexure is aligned with the said second firing means. I

12. A fuse comprising a housing, a beam member having helical paths of opposite hand pivoted in said housing for rotation and for translation longitudinally of said housing, receiving means for said beam member in the path of translation thereof to prevent rotation of said beam member in one extreme position of its translation, resilient means biasing said beam member away from said receiving means, and centrifugal means received on said beam member, and having means complementarily engaging said helical paths, and held against rotation about the axis of said helical paths.

13. A fuse comprising a member of oblong transverse section carrying a firing component and mounted for rotation about an axis radially of the fuse axis to rotate the firing component from safe to armed position, mass means posi-. tioned in the fuse for radial recession along said first axis on rotation of the fuse, and a connection between said mass means and said member constructed and arranged to turn said member to armed position of said firing component in response to recession of said mass.

14. A fuse comprising a bar of oblong transverse section, helical twists of opposite hand on said bar and centrifugal weight means mounted on said fuse for rotatively constrained translatory motion generally away from the axis of the fuse and having guide means located for engagement with the said twists at points offset from their axis of helix whereby the twists act as followers to rotate the bar on centrifuging of the weight means.

15. A fuse comprising an elongated member of oblong transverse section, oppositely threaded helical paths on said member, centrifugal weights slidingly received on said elongated member, means in the fuse constraining said weights substantially to a single degree of freedom of motion with respect to the fuse bearing a substantial component transverse of the fuse, and guide means on said weights engaging the helical paths at points ofiset from'their axis whereby to occasion rotation of the helices substantially about their axes by virtue of the single degree of freedom of motion of theweights.

16. A fuse comprising an elongated member, helical paths of opposite hand on said elongated member, a firing component carried by said elongated member and extending transversely thereto, and centrifugal weight means comprising a hoop with openings dimensioned to engage a portion of said spiral paths in a manner complementary thereto, said hoop arranged for motion of its portions bearing the openings in a direction generally transverse to the fuse axis whereby 'to turn the elongated member on flexing of the hoop, and means. to mount the hoop in a projectile for rotation therewith.

17. A fuse comprising opposed centrifugal members, and a firing component of oblong transverse section extending between and slidably received in said members and transversely of the fuse, thread connections between said component and said members, of opposite hands, respectively, and means constraining said members to motion radially of the fuse only, whereby, as the members recedefrom each other the component is forced to revolve about'an axis defined by the path of recession of said members.

18. In combination, opposed centrifugal units, means constraining said units to a radial path of flight without rotation about the general line of said path, a cross member of oblong transverse section extending between said units and slidably' received therein, and a connection between 'said member and said units comprising cam and'follower means constituting a couple with respect to the longitudinal axis of the cross member whereby the latter is constrained to rotateabout an axis directed in the line of recession of said units on centrifuging thereof.

19. 'A' fuse comprising an elongated firing com ponent, opposed centrifugal means received on said component, cam and follower means between said component and said centrifugal means constructed and arranged to produce a turning couple on said component about its longitudinal axis on recession of said centrifugal means, and means to prevent turning of said component while subject to'setback forces.

WILFRED E. 'I'I-HBODEAU.

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

' UNITED STATES PATENTS