US2856855A - Retainer assembly for a fuze - Google Patents

Description

Oct. 21, 1958 s, p, o ow -rz 2,856,855

RETAINER ASSEMBLY F OR A FUZE' Filed Oct.- 13, 1955 INVENTOR.

5 amuel D.Hnruwi cz 2 BY ATTDRIVEZ' E1.

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RETAINER ASSEMBLY FOR A FUZE Samuel D. Horowitz, Tonawanda, N. Y. assignor to the vUnited States of America as represented by the Secretary of the Army Application October 13, 1955, Serial No. 540,361 3 Claims. (Cl. 102-79 This invention relates to a centrifugally-armed, impact type fuze and, more particularly, to a fuze of this type is slidably mounted in the bore of barrel 18 and is provided at its rearward end with a striker 22 which nestles in bore 13 when the fuze is in unarmed relation to lock the rotor in safe position. The pin also has a mushroomshaped head 23 at its forward portion as clearly shown upon Figs. 1 and 5. The rearward face of head 23 is con-' cave as at 31 and is held against the forward planar face 16 of the retainer body 14, when the fuze is in unarmed relation, by a cross pin or rider 24 diametrically received in the rearward portion of firing pin shank 21 and which contacts the helical or cammed edges 19 of barrel 18.

which is positively maintained in safe or unarmed posi tion under all conditions of handling and is armed in an equally positive manner only after the projectile carrying the fuze has attained maximum spin in firing and is well along on its trajectory, and free and clear of the gun.

The principal object of the invention is to provide a fuze that is safe for handling, transporting, and ramming,

' that is bore safe, armed only after the projectile is in free flight and relatively simple and easy to fabricate and assemble.

'The specific nature of the invention as well as other objects and advantages thereof, will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. l is a longitudinal section to an enlarged scale taken through ajfuze constructed in accordance with the invention, v

Fig. 2 is a cross section taken along line 2-2 of Fig. 1 and looking in the direction of the arrows,

Fig. 3 is a cross section taken along line 3-3 of Fig. l I

and looking in the direction of the arrows,

Fig- 4 is a perspective view of a retaining barrel hellx or cam forming a component of the retainer assembly,

Fig. 5 is a similar View tion.

Referring more particularly to the drawing, wherein like reference characters designate like or corresponding parts throughout the different views, reference numeral 1 designates generally a nose portion of a projectile having a fuze body designated generally by 2 attached thereto. The nose portion of projectile 1 contains a bursting charge 3 and is counterbored as at 4 and internally threaded at 5 to receive the base portion 6 of fuze body 2 which is externally threaded as at 7. Fuze 2 is bored axially as at 9 to receive a booster 10, and counterbored as at 8 to receive arming mechanism.

The rearward portion of bore 8 is generally hemispherical and houses an arming rotor or ball 11 adapted for rotation therein. Rotor 11 has a diametral bore housing a detonator 12 therein and is bored radially at a point 13 on its surface oifset from the diametral axis of detonator 12.

Fixed to the base portion 6 by suitable means such as staking at 6a, is an axially disposed retainer body 14 having a concave rearward face 15 receiving the forward portion of rotor 11, and a forward planar face 16. Retainer body 14 is provided with an axial bore 17 to receive a' tubular retainer barrel helix or sleeve 18 as best seen in Fig. 1. Barrel 18 is provided with a pair of longitudinal diametrically disposed slots opening through its rearward edge each having one corresponding edge in the form of a helix l9 and a splined or serrated forward surface 20 having a press fit within bore 17 of retainer body 14 to prevent rotation of the barrel when inserted into bore 17. A firing pin comprising a shank 21 ofthe firing pin of the inven- Rotation of the firing pin is prevented by an arming spring 25 which has a semicircular portion received in an annular groove 26 in the base of the retainer body 14 and integral forwardly protruding prongs 32 which lie in a pair of diametrically disposed longitudinally-extending notches 27 cut in the retainer body 14, as best seen in Fig. l. The prongs 32 extend forwardly beyond the body 14 and their free ends engage in a pair of diametrically disposed notches 28 formed in the outer peripheral surface of head 23. See Fig. 5. A number of arming balls 29 shown as three in number, are received in the space formed by the planar face 16 of the retainer body and the concave rearward face of the head 23.

A cover or windshield 30 is provided to protect the nose portion of the fuze and to provide access to the operating elements.

The operation of the fuze is as follows:

As illustrated in Fig. 1, the fuze is shown unarmed. In this position, the cross pin 24 of firing pin shank 21 lies at the base of the barrel 18 in contact with the rear portion of the helical edges 19 and is maintained in this position by'engagement of the spring prongs 32 in notches 28 of head 23. This holds the striker 22 in the bore 13 of the rotor 11, and until it is removed therefrom, the fuze is in an unarmed or safe condition and will withstand any linear acceleration or deceleration i. e. jolt, drop, ramming, etc.

Upon being subjected to annular acceleration, in firing, centrifugal force -will cause the prongs 32 of arming spring 25 to move radially outward of slots 28 in head 23, thus rendering the firing pin 21 capable of revolving in either direction and moving forward to withdraw striker 22 from bore 13 of rotor ball 11.

Angular acceleration due to clockwise spin in the model shown, will cause the projectile 1, fuze 2, retainer body 14, and barrel 18 to lock up more securely on the firing pin with the result that the pin 21, despite release by spring prongs 32, will be momentarily held with its striker 22 in bore 13 to thereby guarantee bore safety.

Upon contacting the turbulence caused by the propellent gases and air pushed out in front of the projectile at the muzzle of the weapon, the aforesaid lock up is neutralized or broken and the mechanism is ready for arming.

Centrifugal force acting upon arming balls 29 will cause them to move outward against the inclined under:

surface 31 of the head portion 23 thus positively camming" the firing pin forwardly. The balls 29 then fly free of the assembly and into the space formed between the retainer body 14 and cover 30 where they are held.

Arming delay is achieved in this lapse of time between the entry of the fuze and projectile into the turbulent field and the time necessary for the arming balls 29 to apply their full force against the camming surface 31 of the firing pin head 23 and the resistance of the pin 24 against the helical edges 19 of the barrel 18, demanding angular as well as linear movement of the firing pin in order to free rotor 11.

As this is accomplished, the striker 22 of the firing pin 21 is withdrawn from the bore 13 in the rotor 11, allow- (maintained in contact with the cover 3%) upon contact with a target, isrdriven rearward, causing the striker 22 to penetrate the detonator lland initiate the detonator and the main charge 3 of the projectile.

It'is' apparent from the foregoing, that a novel and highly efficient fuze has been designed which accomplishes the objects previously stated. The elements comprising thezfuze are relativelyeasy to fabricate and assemble andthe desired delayed-action arming, is positive and certain.

Whilea preferred form of invention has been shown and described, various modifications and substitutions of equivalents will occur .to those skilled in the art after a study'of'the foregoing disclosure. Hence, the disclosures should be taken in an illustrative rather than a limiting sense, and it is my desire and intention to reserve all'inodifications within the scope of the subjoined claims.

Having fully disclosed the invention, what is claimed and desired to secure by Letters Patent is: l

1. In a centrifugally armed fuze, a fuze body having a longitudinal axis of symmetry, a rotor journaled in said body for rotation froma first safe position to a second armedposition, means fixed with said body forwardly of said rotor and defining a rearwardly-facing camming edge helical about said axis forwardly in the direction of spin of said fuze in firing, a firing pin carried by said body coaxial of said axis and translatable forwardly from a first position engaging and holding said rotor in safe position, to a second position freeing said rotor for rotation to armed position, said pin including an enlarged head having a rearwardly-facing forwardly and inwardly inclined cam surface, means fixed with said body and defining'a forwardly-facing surface forming with said cam surfaceanannular chamber, at least one ball positioned in said chamber and acting to cam said firing pin forwardly in response to radially outward motion of said ball, and a cam rider fixed with said firing pin and engaging said helical edge.

2. A centrifugally armed impact fuze comprising, a

fuze body having a central longitudinal axis, a rotor jourl '4 locking said rotor, forwardly to a position releasing the same, said firing pin having an enlarged head, means fixed with said body and defining with said head an annular chamber of decreasing dimension in the axial direction radially outwardly of said axis, a plurality of rolling elements mounted insaid chamber, means constraining said firing pin to initially rotate as a unit with said body and releasable in response to centrifugalbforce, and a rider fixed with said firing pin and engaging said helical edge.

in a ccntrifugally-armed point detonating impact fuze, a fuze body, having a longitudinal axis of 'symmetry, a ball rotor journaled ina sphericaltcavity incsaid body for rotation under centrifugal. force from a safe to an armed position, a tubularsleeve fixed withsaid body forwardly of said rotor along said axisand having diametrically-opposed cut-outs in its side walls defining first and second duplicate helical camming edges, avfiringpin slidable axially in said sleeve from arearward position engaging and holding said rotor in safeposition to a forward position releasing said. rotor for: rotation to armed position, a pair of cam riders fixedin diametrically ,op: posite positions on. said pin, each engaging a respective camming edge, said pin including ahead having a rear- 'wardly-facing, outwardly and rearwardly disposed cam surface of revolution, about said axis, means fixedwith said bodydefining a forward planar face transversely of saidlaxis and defining with the cam surface of said head, an annular chamber, a plurality of balls confined in said chamber and operable in response to centrifugal force, to cam said pinto forward position, and a spring fixed with. said head sand having, diametrally-disposed prongs extending forwardly with their endsseated in respective notches in said head, said prongs. initially holding said firing pin in rearward POSltiOIlfllld causing thesame to rotate as a unit with said body but releasing the same under centrifugal force of -rotation about said axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,313,930 Taylor Aug. 26, 1919 1,316,131 Baldwin Sept. 16, 1919 2,446,019 Nichols July 27, 1948 2,595,757 Brandt i May 6, 1952 2,790,390 Baker Apr. 30, 1957 FOREIGN PATENTS Sweden Aug. 27,

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