US2748707A - Auxiliary detonator fuze for antiaircraft projectile - Google Patents

Description

June 5, 1956 R, GRAUMANN 2,748,707

AUXILIARY DETONATOR FUZE FDR ANTI-AIRCRAFT PROJECTILE Filed June 25, 1945 2 Sheets-Sheet 2 I l 4e 37 47 45 e7 737172 46 7o 36 68: 1 768 7| i glwuc/wm 53 54 58 @WMM/MM United States Patent M' AUXILIARY DETONATOR FUZE FOR ANTI- AIRCRAFT PRGJECTILE Raymond L. Graumann, Alexandria, Va.

Application June 23, 1945, Serial No. 601,285

3 Claims. (Cl. 102--79) (Granted under Title 35, U. S. Code (1952), sec. 266) This invention relates to a safety auxiliary fuze for a projectile and more particularly to a fuze for use with a projectile employing the usual time delay nose fuze and known to those skilled in art as an anti-aircraft or highexplosive projectile and used by the armed forces for the purpose of destroying enemy aircraft and the like. More especially this invention relates to a safety auxiliary fuze for an 4anti-aircraft projectile adapted to be fired from a gun and provided with means adapted to explode an explosive charge within the projectile in predetermined time delayed relation with respect to the firing of the projectile from a gun in which contact with a target is not necessary to fire the charge, The invention relates to an auxiliary fuze for a projectile in which the firing pin and detonator are maintained in a safe position with respect to each other and will remain in safe position vuntil the projectile has attained a predetermined speed of rotation after the projectile has been fired from a gun, and until the force of acceleration of the projectile has diminished to a value corresponding to the force of acceleration acting on the projectile at a safe distance from the gun after the projectile has been tired therefrom.

One of the objects of the present invention is the provision of a new and improved means for preventing the premature firing of an explosive charge within a projectile during the transportation, handling, loading and firing of the projectile from a gun.

-Another of the objects `is to provide a new and irnproved device for preventing the premature ring of an explosive charge within a projectile in which means are provided for maintaining a rotatable detonator in safe position and in which a slideable ring pin is locked in s afe position until the velocity of the projectile has reached substantially the maximum value after the projectile has been red from a gun.

lA further object is to provide a new and improved device for maintaining a rotatable detonator and tiring pin of a projectile in a safe or unarmed position until the vprojectile has passed beyond the muzzle of a gun, whereupon the rotatable detonator will be actuated to a tiring position and a lock be removed from the firing pin under the inuence of centrifugal force.

A still further object of the invention is to provide new and improved means for a projectile for maintaining the rotatable detonator and the slideable tiring pin of a projectile in a safe position until the projectile is shot clear ofthe gun which is reliable in operation, and which possesses all of the desired qualities of safety and durability.

Still other objects and advantages will be apparent from the following description taken in connection with the .accompanying drawings, of which: Fig. 1 is a sectional View of a high-explosive time delay projectile employing the auxiliary fuze of the present invention according to a preferred'embodiment thereof; y Fig, 2 ifs an enlarged sectional view of the auxiliary fuzeconstructedin accordance with the present invention;

Z ,748 ,707 Patented 'June 5, 1956 Fig. 3 is an end elevational view of the auxiliary fuze;

Fig. 4 is a sectional view of the auxiliary fuze similar to Fig. 2 but showing the device in an armed condition;

Fig. 5 is a sectional View of the fuze taken on line 5 5 of Fig. 4;

Fig. 6 is a sectional View of the fuze taken on line 6 6 of Fig. 4;

Fig. 7 is a face view of the rotor supporting the detonator;

Fig. 8 is an edge view of the rotor and detonator; and,

Fig. 9 is a fragmentary sectional view showing the rotor in an unarmed condition.

Referring now to the drawings for a more complete understanding of the invention and more particularly to Fig. l thereof, there is shown thereon a projectile indicated generally by the numeral 10 having an annular groove 11 therein adapted to engage a complementary portion of a cartridge case i2 to which the projectile is secured, as is well known in the art to which the present invention pertains. The projectile is also provided with an annular sleeve 13 of material suitable for the purpose such, for example, as copper adapted to be engaged by the riing of the gun as the projectile is propelled outwardly therefrom by the explosion of the explosive charge 14 arranged within the cartridge case 12 and thereby impart rotary movement to the projectile about the axis thereof as the projectile moves through thebore of the gun. The projectile is thus adapted to be propelled along a predetermined trajectory and to spin or rotate continuously about its axis throughout the trajectory as the result of the rotary movement imparted thereto by the riing of the gun.

The projectile 1@ comprises a shell 15, the forward end thereof being screw-threaded as at 16 having engagement with a screw-threaded nipple 17 provided on a plug or adapter 1S and thus the plug is secured to the shelly 15 of the projectile. The adapter 18 is provided with a screwthreaded opening 19 having the axis thereof arranged coaxially with the axis of the projectile into which a screwt-hreaded extension 21 provided on the usual time delay fuze 22 isv threaded, whereby the time nose fuze is secured to the projectile at the leading end thereof. The shell 15 comprises a rear wall 23 integrally formed therewith in which a screw-threaded'opening 24 is provided whereby the shell may be lle'd with an explosive or bursting charge 25. After the shell has been filled with the explosive bursting charge, a screw-threaded plug 26 i`s threaded into the opening 24 thus sealing the opening and retaining the explosive bursting charge within the shell15.

An auxiliary fuze generally indicated by the reference character 27 is secured within the adapter 18 and cornprises a casing 28 having a screw-threaded portion thereon adapted to have engagement with a screw-threaded opening 29 provided in the adapter 18 which communicates with`the opening 19 therein whereby the auxiliary fuze is secured within the adapter in proximate spaced rela'- tion with respect to the time fuze 22. The auxiliary fuze 27 isV adapted to extend a predetermined distance within the bursting charge 25', thus providing means for eX- ploding the burstingV charge within the shell 15 in pre'- determined time delayed relation with respect to tiring of the time fuze after the projectile has been fired from a gun, as will be more clearly apparent as the description proceeds. The casing 23 is provided with a recess 31 in one end thereof having a booster charge 32 arranged therein. The booster charge is retained within'the re`- cess 31 by a cap 33 adapted to have screw-threaded engagementV with a reduced screw-threaded nipple 34 provided on one end of the casing 28. A cushion disk and moisture proof seal 35 composed of any material suitable for the purpose such, for example, as blotting paper or the like is disposed between the cap 33 and the end of the nipple 34, the disk being clamped against the lower end of the nipple and booster charge by the cap 33 in such a manner as to prevent moisture from seeping therethrough and also prevent shifting of the booster charge within the recess, and thus premature tiring of the booster charge due to shifting of the charge during transportation handling and when the projectile is red from a gun is prevented. The casing 28 is also provided with a recess or bore 36 adapted to extend substantially therethrough, the recess 36 being separated from the recess 31 by a partition 37 integrally formed on the casing 28.

A firing unit generally indicated by the reference character 38 is arranged within the recess or bore 36, one end of which engages the outer surface of the partition 37 and the other end thereof has disposed thereon a moisture proof protector disk 39 composed of any material suitable for the purpose such, for example, as oil paper, tin foil or the like. The firing unit 38 is retained Within the recess 36 by an annular member 41 adapted to have threaded engagement with a threaded portion 42 of the recess or bore 36. The tiring unit 38 is also adapted to have abutting relation with respect to the protector disk 39 and thus it will be apparent, particularly with reference to Figs. 2, 4 and 5 of the drawings, that the ring unit is clamped in a xed position within the recess 36 by the annular member 41 and the disk 39 is employed as a seal to exclude moisture therefrom. The annular member 41 is provided with a centrally disposed opening 40 arranged coaxially with respect to the axis of the projectile and having a piston or cup 30 slideably arranged therein, the purpose of which will be hereinafter more fully described. The annular member 41 is also provided with a pair of recesses 43 adapted to provide means whereby a suitable Wrench such, for example, as a spanner wrench may be applied thereto for threading the annular member into the threaded portion of the bore 36 thereby compressing the disk 39 between ring unit 38 and the annular member.

The ring unit 38 comprises a relatively thin casing or container 44 composed of any material suitable for the purpose such, for example, as brass or the like having enclosed therein a rotor block indicated by the reference character 45, one end thereof being adapted to have abutting relation with respect to one end of a firing pin and detent block 46.

Arranged within the casing 44 in abutting relation with respect to the other end of the rotor block 45 is a disk 47 provided with a nipple 48 adapted to extend through an opening or bore 49 formed in the partition 37. The block 46 and disk 47 are each provided with a recess 51 in which flange portions 52 respectively provided on each end of the casing 44 are adapted to seat whereby the blocks 45 and 46 and the disk 47 are maintained in fixed abutting relation with respect to each other in such a manner as to provide a unitary firing mechanism for the projectile.

A rotor or turret 53 composed of any material suitable for the purpose such, for example, as aluminum having an opening 54 extending therethrough, the rotor being arranged within a recess 55 is provided in the rotor block 45 and adapted to have rotative movement therein. A pair of weights 56 of high specific gravity and composed of any material suitable for the purpose such, for example, as lead are arranged in diametrically disposed apertures provided in the rotor 53, in unbalanced relation with respect to the axis of the fuze when the rotor is in an unarmed position within the recess 55. When the projectile starts to rotate as a result of the rotary movement imparted thereto by the riflng of the gun as the projectile is fired therefrom, the weights 56 will tend to move outwardly in response to centrifugal force and will spin the rotor in an armed position when the projectile has reached the maximum speed of rotation. Arranged within the opening 54 of the rotor is a compound ring unit indicated generally by the reference character 57. The firing unit includes a detonator 58 comprising a casing 59 having a detonating charge 60 arranged therein. The tiring unit also includes a percussion cap 61 arranged within the opening 54 of the rotor in abutting relation with respect to the detonator casing 59 and comprises a base member 62 having an anvil 63 formed thereon in abutting relation with respect to an explosive cap 64 secured to the base member in any suitable manner and adapted to re the detonator. The base member 62 of the percussion cap is provided with a ash channel 65 in communication with a bore 66 provided in the casing 59 of the detonator to provide means whereby a ash or burst of ame from the explosive cap 64 when red may enter the flash channel 65 and bore 66 and initiate firing or the detonator charge 60.

It will be understood, however, that means are provided for the projectile whereby the rotor is prevented from rotating or, in other words, the rotor is maintained in a safe or unarmed position during handling, transportation, and during loading of the projectile into a gun. Such means are clearly shown on the drawings, especially Figs. 5, 6 and 9 thereof, and comprise a pair of diametrically disposed releasable latching members 67, each of the members having a reduced extension or protuberance 68 formed thereon adapted to seat in a pair of recesses 69, respectively provided on opposite sides of the rotor 53. The members 67 are slidcably supported within a pair of cup-shaped members 71 respectively arranged in diametrically disposed apertures 72 provided in the rotor block 45 and each member 67 is adapted to be urged inwardly toward the rotor 53 by springs 73 respectively arranged in bores 74 provided within the rotor block, the springs being in engagement with the bottom wall of the bore and the upper wall of the cup-shaped member 71. Thus the extensions 68 are maintained in engagement with the recesses 69 thereby preventing rotation of the rotor until after the projectile has been ired from the gun and a predetermined speed of rotation of the projectile has been reached.

It will be understood, however, that the spring pressed members 67 are adapted to maintain the rotor supporting the compound tiring unit 57 in a safe or unarmed position with respect to a lead-in charge 75 arranged in an aperture provided in the nipple 48 of the disk 47. The rotor is also maintained in a safe position with respect to a tiring pin as will hereinafter appear in greater detail as the description proceeds. The rotor supporting the detonator and percussion cap is thus maintained in a safe position as the projectile is fired from a gun by the extensions 68 extending into the recesses 69 and will remain in safe position until the acceleration of the projectile has reached substantially a zero value and the speed of rotation thereof about the axis of the projectile has reached a predetermined value. When this occurs the extensions 68 will be withdrawn from the recesses 69 in the rotor and the rotor will move to the armed position shown on Figs. 4, 5 and 6 of the drawings when the projectile has reached a maximum speed of rotation.v

The blocks 45 are each provided with a pair of bores in registration with respect to each other thereby forming a pair of gas and pressure lrelief chambers 70 adapted to relieve the pressure from the expanding gases should the detonator be red prematurely when in an unarmed position thereby preventing premature detonation of the booster charge and explosion of the shell.

The rotor is so constructed as to be balanced statically, that is, any two parts thereof diametrically opposed and in a plane crossing the axis of the rotor are of equal weight. The specific gravity of the compound tiring unit, however, is less than the specific gravity of the surrounding material and the specific gravity of the weights 56 is greater than the specific gravity of the surrounding material whereby a dynamic couple is produced by rotation of the shell suicient to rotate the rotor into armed position with the compound tiring unit in alinement with the rotational axis of the projectile after the projectile leaves the muzzle of the gun.

A firing pin 76 is slideably arranged within the block 46 comprising a head 77 disposed within a recess 78 formed in the block 46 and also having a reduced shank or hammer member 79 connected thereto extending into an aperture 81 also formed in the block 46 and adapted to communicate with the recess 55 provided in rotor block 45 thereby providing means for firing the compound firing unit to initiate firing of the bursting charge within the shell 15 in response to the actuation of the piston by the explosive pressure produced by the time nose fuze as the nose fuze functions, the movement of the j piston 30 also causing rupture of the seal 39.

The block 46 is also provided with a pair of diametrically arranged apertures 82 within which are respectively disposed a pair of locking detents 83 adapted to be releasably maintained in engagement with the shank 79 of the tiring pin by springs 84 respectively arranged within recesses 85 provided in the detents 83, the springs being disposed between the bottom wall of the recess and a retaining member 86 secured to the block 46 in any suitable manner, and thus the detents are yieldably and inwardly urged against the shank 79 of the tiring pin while the projectile is at rest.

With the detents 83 in locking position as shown on Fig. 1 of the drawings, the firing pin is maintained locked in safe or unarmed position and prevented from being brought into contact with the percussion cap 61 by reason of the engagement of the inner portions of the detents with the inner surface or shoulder 87 of the firing pin.

The force resulting from the acceleration of the projectile in response to the expansion of the gases within the gun is applied in a direction along the path of travel of the projectile and is well known in the ordnance art as a setback force. This setback force decays to zero as the projectile leaves the muzzle of the gun. Therefore, it will be understood that the setback force applied to the ring pin and detents will tend to bind the detents in the apertures 82 and also tend to bind the shoulder 87 of the tiring pin against the inner portion of the detents, thus preventing movement of the detents away from the tiring pin until the setback force has reached substantially a zero value and the rotation of the projectile has reached a maximum value after the projectile has passed the limits of the muzzle of the gun.

As the projectile is propelled along the bore of the gun by the explosion of the charge 14, the riing of the bore engages the sleeve 13 and imparts rotative movement of the projectile, thereby causing the detents 83 to be spun about the axis of the projectile and a centrifugal force to be generated thereby. It will be understood, however, that this force is of sufficient strength to overcome the tension of the springs 84 and to cause the detents 83 to move outwardly to an unlocking or armed position and thus provide a clear path of travel for the ring pin.

On Figs. 4 and 5 of the drawings the rotor is shown moved in an armed position and the firing pin is unlocked by centrifugal force during the travel of the projectile along the trajectory. That is to say, in response to centrifugal force the latching members 67 are moved out of the recesses 69 when the centrifugal force has reached sufficient strength to overcome the tension of springs 73 whereby the rotor is released for movement to an armed position within the recess 55 in the rotor block 45 and centrifugal force will also maintain the detents 83 in the unlocking or armed position when the force has reached suicient strength to overcome the tension of the springs 84 arranged therein, thus permitting the detonator and percussion cap to be moved into the path of travel of the firing pin and unlocking the tiring pin respectively. Thus the ring pin 76 is in readiness to be driven against the explosive cap 64 of the percussion cap 61 by the piston 30 which is operated by the sudden pressure applied thereto when the time fuze functions, as is well known in the art. It will be understood that the time fuze 22 is of any well known construction and is adapted to supply sucient pressure when operated to force the piston 30 into engagement with the tiring pin and drive the ring pin against the cap 64 with suflicient force to explode the cap and initiate firing of the bursting charge.

As the gun is red the initial movement of the projectile away from the shell casing is a motion of translation and when the projectile has moved a predetermined distance within the bore of the gun, the sleeve 13 engages the riing of the bore and rotation of the projectile is initiated thereby, Therefore it will be apparent that the setback force is applied to the projectile prior to rotative movement thereof and will maintain the rotor and firing pin in an unarmed position until the setback force has diminished substantially to zero value and the centrifugal force has reached a maximum value, thereby providing an arrangement in which there is no possibility of prematurely arming the fuze until the projectile has passed beyond the muzzle of the gun.

In the event, however, that the detonator should be red during the assembly or inspection of the fuze while the rotor supporting the detonator is in a safe position, substantial injury to the personnel within the vicinity of the fuze is prevented by the provision of the pair of pressure relief chambers within the fuze structure.

The many advantages of the auxiliary fuze constructed in accordance with the present invention will be readily apparent from the foregoing description, taken in connection with the accompanying drawings and, although a preferred embodiment of the device is illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which fall within the scope of the invention as claimed.

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.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An auxiliary fuze for a high-explosive projectile comprising a casing, a disk arranged within one end of said casing and having a lead-in charge arranged therein, a block member arranged within the other end of said casing, a firing pin releasably locked within said block member and adapted to have sliding movement therein when released, means for actuating the firing pin, means controlled by centrifugal force for releasing said firing pin, a rotor block disposed between said disk and block member and having a recess therein, retaining means provided on each end of said casing in engagement with the disk and block member respectively for clamping said disk, block member and rotor block in fixed position within said casing, a rotor releasably maintained within said recess in a safe position and adapted to have rotative movement therein when released, means controlled by centrifugal force for releasing said rotor, means responsive to centrifugal force for moving said rotor to an armed position after the rotor is released, and a detonator arranged within said rotor and adapted to tire said lead-in charge while the rotor is in said armed position as the detonator is fired by the actuation of said firing pin.

2. An auxiliary fuze for a high-explosive projectile comprising a casing, a disk arranged within one end of said casing and having a lead-in charge arranged therein, a block member arranged within the other end of said casing, a firing pin releasably locked within said block member and adapted to have sliding movement therein when released, means for actuating the tiring pin, means controlled by centrifugal force for releasing said firing pin, a rotor block disposed between said disk and block member and having a recess therein, retaining means provided on each end of said casing in engagement with the disk and block member respectively for clamping the rotor block in fixed position Within said casing, said rotor block and block member having a pair of registering recessed portions respectively arranged therein to provide a pair of pressure relief chambers in communication with said recess, a rotor releasably maintained within said recess in a safe position and adapted to have rotative movement therein when released, means controlled by centrifugal force for releasing said rotor, means responsive to centrifugal force for moving said rotor to an armed position after the rotor is released, and a detonator arranged within said rotor and adapted to fire said lead-in charge while the rotor is in said armed position as the detonator is red by the actuation of said firing pin.

3. An auxiliary fuze for a high explosive projectile, comprising a cylindrical member having a booster charge arranged therein, means for hermetically sealing said booster charge, a casing disposed within said cylindrical member, a disk arranged within one end of said casing having a lead-in charge arranged therein adapted to ire said booster charge, a rotor block arranged Within said casing in abutting relation with respect to said disk and having a recess therein, a block member arranged within said casing in abutting relation with respect to said rotor block, ange members provided on each end of said casing in engagement with the disk and block member respectively for clamping said disk, rotor block and block member together to provide a unitary firing unit, a rotor releasably maintained within said recess in a safe position and adapted to have rotative movement therein when released, means controlled by centrifugal force for releasing said rotor, means responsive to centrifugal force for moving said rotor to an armed position after the rotor is released, a detonator arranged within said rotor and adapted to lire said lead-in charge when said rotor has been moved to an armed position and said detonator has been ired, a firing pin releasably locked within the block member and adapted to have sliding movement therein when released, means controlled by centrifugal force for releasing said firing pin to lire said detonator when the rotor has moved the detonator in line with said firing pin, means for hermetically sealing said fuze, said last named means including a retaining member, and means Within said retaining member for actuating said firing pin when the rin'g pin has been released.

References Cited in the file of this patent UNITED STATES PATENTS 1,310,046 Asbury July 15, 1919 1,531,716 Remondy Mar. 31, 1925 2,359,752 Del Prato Oct. 10, 1944 2,392,430 Teitscheid Jan. 8, 1946 2,392,884 Semple Ian. 15, 1946 2,441,939 Nichols May 18, 1948 2,546,999 Graumann et al Apr. 3, 1951 FOREIGN PATENTS 218,586 Great Britain July 10, 1924 257,335 Great Britain Aug. 27, 1926 694,402 France Sept. 15, 1930 837,467 France Nov. 12, 1938

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