US2963974A - Impact detonating fuze with arming delay - Google Patents

Description

Dec. 13, 1960 2,963,974

IMPACT DETONATING FUZE WITH ARMING DELAY I Y. SEKELLA 2 Sheets-Sheet 1 Filed May 9, 1958 Dec. 13, 1960 Y. SEKELLA 2,963,974

IMPACT DETONATING FUZE WITH ARMING DELAY Filed May 9, 1958 2 Sheats-Sheet 2 Illl III I I .36 II "III I I 1 5 57 42 I as $1 I i In W WITNESS IMPACT DETONATING FUZE WITH ARMIN G DELAY Youston Sekella, Elmira, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed May 9', 1958, Ser. No. 734,145

4 Claims. (Cl. 10284) The present invention relates to an impact detonating fuze with arming delay and more particularly to such a fuze incorporating a mechanical time delay mechanism.

Impact detonating missiles to be launched by mortars as presently constituted are not fully protected from premature explosion due to the forces engendered by the discharge of the mortar. It sometimes happens, therefore, that the set back or launching force causes detonation of the missile as soon as it clears the muzzle of the mortar with consequent jeopardy to the adjacent personnel.

It is an object of the present invention to provide a novel impact detonating fuze which incorporates means for positively preventing the arming of the fuze for a predetermined time after the missile leaves the mortar.

It is another object to provide such a device in which the delay mechanism is in the form of a gear train and escapement device which controls a positive stop for the arming device.

-It is another object to provide such a device in which the initiating mechanism is arranged to hold the primer out of operating position until the firing pin is moved to its armed position, whereby no amount of rough handling, set-back or impact forces can cause premature explosion of the missile.

Further objects and advantages will be apparent from the foregoing description taken in connection with the accompanying drawings in which;

Fig. 1 is a vertical substantially mid-sectional view of a fuze incorporating a preferred embodiment of the invention, some of the parts being shown in elevation in the interest of clarity, the parts being shown in the positions assumed when the fuze is armed;

Fig. 2 is a sectional detail taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a detail in perspective of the nose member of the fuze mechanism;

Fig. 4 is an enlarged substantially mid-sectional detail of the fuze showing the primer mechanism and the firing pin in the normal safe or disarmed position;

Fig. 5 is a view similar to Fig. 4, showing the positions of the parts after the missile has left the mortar, during the time delay period prior to the fuze becoming armed, and

Fig. 6 is a detail of the escapement mechanism for delaying arming of the fuze.

In Fig. 1 of the drawing, there is illustrated the body 1 of a fuze which is provided with a lateral passageway 2 in which is slidably mounted a carrier member 3, which holds an explosive primer cartridge 4 in a central location when the fuze is armed. A spring 5 urges the carrier 3 toward its armed position as here illustrated.

The body 1 is formed with a socket 6, which is internally threaded for the reception of a threaded extension 7 of a nose member 8, which serves to carry the timing and initiating assembly. A cup-shaped striker 9 is slidably and rotatably mounted in the nose 8, and is formed with an outwardly extending projection 11 slidably re- 2,963,974 Patented Dec. 13, 1960 ceived in an internal axially extending groove 12 in the nose.

As best seen in Fig. 2, the axially extending groove 12 intersects an arcuate groove 13 which extends around the interior of the nose and terminates at an enlargement forming a seat 14 for the reception of the projection 11 when the fuze is in the disarmed or safe condition.

Yielding means are provided for rotating the striker 9 to move the projection 11 from the safety position designated by A in Fig. 2 to the other end of the groove 13 as shown at B, and then for projecting the striker 9 from the nose 8 until the projection 11 occupies the position C in Fig. 2. As illustrated in Fig. 1, this means comprises a torsion spring 15 anchored at one end as shown at 16 to the striker 9 and at its other end as shown at 17 to a partition member 18, which is fixedly mounted in any suitable manner in the nose member 8. This is accomplished as illustrated by means of a cupshaped gear casing member 19 anchored in the threaded extension of the nose 8 by a lock ring 20 and having one or more tongues 22 forced into inclined keyways 23 formed in the periphery of the partition member 18. Said yielding means also preferably includes a compression spring 24 located between the projecting end of the striker 9 and the partition member 18.

A firing pin 25 is fixed at one end in the striker 9 as indicated at 26 and extends axially through the partition member 18 and gear case 19 into position to engage and initiate the primer 4 when the primer is in armed position and the striker 9 is depressed or strikes the target.

Means are provided for retarding the rotation of the striker 9 in the nose 8 to delay the arming of the fuze for a predetermined time after the projection 11 is released from its seat 14 by the set-back force as the missile is launched. For this purpose the firing pin 25 is formed with a non-circular cross section and an annular planet carrier 27 having a conforming central opening is slidably mounted thereon so as to rotate therewith. Pins 28 mounted in the carrier 27 provide bearings for a plurality of planets 29 Which mesh exteriorly with an orbit gear 31 formed in the interior of the gear case member 19. The planets also mesh with a sun gear 32 which is journalled on the firing pin 25. The sun gear 32 has fixedly mounted thereon an escapement wheel 34 which, as best shown in Fig. 6, engages a plurality of pallets 35 mounted for oscillation on bearing pins 36 fixed in the base of the gear casing 19. Rotation of the sun gear 32 thus causes oscillation of the pallets 35, whereby the rotation of the sun gear is controlled.

The slide 3, which carries the primer 4, is provided with an opening 37 into which the point 38 of the firing pin 25 projects when the missile is in disarmed condition as shown in Fig. 4. Rotation of the slide is prevented by suitable means such as a guide-pin 39 engaging in a longitudinal slot 41 in the slide.

Means are preferably provided for normally holding the slide in a retracted position. As shown in Fig. 4 this means is provided in the form of a laterally removable pin 42 which traverses a bifurcated portion of the slide 2 and engages the slide at the base of the furcations. This pin may be removed manually prior to loading the missile, or may be automatically ejected incident to the discharge of the missile from the mortar.

A safety wire 43 traversing the upper end of the nose 8 is arranged to engage in an opening 44 in the striker 9 to hold the striker in disarmed position.

In operation, the safety pin 43 is first removed, and the missile is then placed in the mortar.

When the missile is launched, the set-back or accelerational force causes the projection ll of the striker 9 to be moved out of its seat 14, which permits rotation of the striker to be initiated by the spring 15. The speed of this rotation is governed by the escapement mechanism 29, 32, 34- and 35, whereby the projection 11 does not reach the position 8 in Fig. 2 at the intersection of the circumferential groove 13 with the axial groove 12 until a predetermined time after the missile leaves the mortar.

During this time the engagement of the point 38 of the firing pin 25 within the opening 37 of the slide, as shown in Fig. 5, prevents the slide from bringing the primer 4 into alinement with the firing pin,

After the elapse of the time delay above provided, projection 11 of the striker 9 enters the axial slot 12, and the striker is then projected into its armed position as shown in Fig. 1 and at C in Fig. 2 by the combined action of the springs 15 and 24. At the same time, the withdrawal of the firing pin 25 from the opening 37 of the slide permits the spring 5 to place the primer 4 in operative position whereby the fuze is fully armed. Consequently, when the striker 9 is depressed as on the target, the firing pin 25 is driven into the primer, initiating the explosion of the missile.

Although certain structure has been shown and described in detail, it will be understood that changes may be made in the form and arrangement of the parts Without departing from the spirit of the invention.

I claim:

1. In an impact-detonating fuze for mortar shells, a nose member, a striker slidably and rotatably mounted in the nose member and projecting forwardly therefrom when the fuzc is armed, means normally retaining the striker in retracted position comprising means to release the striker after a predetermined rotation of the striker in the nose, yielding means for rotating and projecting the striker, gear and pallet means mounted in the nose and operatively engaging the striker for controlling the rate of rotation of the striker to delay its projection from the nose, a firing pin fixedly attached to the striker, and p ment with the firing pin, and including means retaining the primer out of alignment with the firing pin until the striker is projected into armed position.

3. In an impact detonating fuze, a nose member, a striker rotatably and slidably mounted in the nose memher and having extended and retracted positions, said nose member having an internal arcuate groove intersected at one end by an internal axial forwardly extending groove and having a forwardly extending enlargement at its other end, and an outwardly extending projection on said striker loosely slidable in said grooves and normally seated in said enlargement when said striker is in the retracted position, yielding means operatively engaging said striker and actuated by launching acceleration forces for rotating the striker to cause said projection to traverse the arcuate groove and for thereafter moving the striker axially in the forward direction to the extended position while said projection traverses the axial groove in the nose member; a firing pin fixed to the striker, a primer movable into and out of the path of travel of the firing pin, means engageable with the firing pin for holding the primer out of said path until the striker has been moved to its advanced position, and means for retarding the rotation of the striker in the nose comprising an escapement mechanism driven by rotation of the striker in the nose.

4. An impact-detonating fuze as set forth in claim 3 in which said yielding means urges the striker in its retracted position in the direction to hold the projection of the striker in said enlargement of the arcuate groove.

References Cited in the file of this patent UNITED STATES PATENTS 1,665,666 Junghans Apr. 10, 1928 1,975,809 Teitscheid Oct. 9, 1934 2,014,393 Mathsen Sept. 17, 1935 2,131,037 Brayton Sept. 27, 1938 2,709,962 Funk June 7, 1955 2,850,979 Hardwick Sept. 9, 1958 FOREIGN PATENTS 16,503 Great Britain 1914

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