ESPOLETA NORTEAMERICANA "DE IMPACTO CON RETARDO"

Esta pieza (7) o "nariz" porta dos sistemas de iniciación situados diametralmente opuestos. El primero consiste en un iniciador (13) y un canal de conducción del fuego (14) para su funcionamiento como "instantánea" y el segundo un iniciador (15) y un retardo (16) para su funcionamiento con "retardo". Estos elementos son retenidos en su sitio gracias a la acción de un tapón (17) que esta en una apertura (18).

Una cavidad (19) en la parte delantera de la "nariz" aloja el sistema de percusión (20) formado por una pieza en forma de "U", donde se alojan dos percutores (21) que tienen un ensanche en su parte superior (22) donde encajan en un rebaje (23) existente en la pieza en forma de "U". Una pieza (24), que encaja en el sistema de percusión, mantiene los percutores en su lugar y el pasador (25) atraviesa el conjunto para que la espoleta este en "seguridad".

Dos huecos cónicos (26) se encuentran en el plano de la nariz (7) que apoya sobre el cuerpo de la espoleta (9). Estos huecos sirven para que encaje la bola metálica (27) empujada por el muelle (28) que se encuentra en el lateral superior del cuerpo de la espoleta, al girar la nariz para seleccionar la forma de funcionamiento y que queden perfectamente alineado el tren de fuego seleccionado. Exteriormente se puede observar el sistema de funcionamiento elegido haciendo coincidir las marcas (33) con la leyenda (32) que indica el sistema elegido.

El detonador (31) esta desalineado del tren de fuego gracias a la acción del pasador de seguridad (35) que retiene la pieza móvil (35) aunque recibe la presión del muelle (36) que sin el pasador de seguridad llevaría al detonador a la posición correcta para recibir el fuego del pistón y trasmitirlo al multiplicador (44) a través del canal (45).

El pasador o tornillo (35) esta sujeto por el pasador (37) que lo atraviesa por su parte final. Este pasador (37), a su vez, es atravesado por el pasador de seguridad (43) que hay que quitar previo al lanzamiento. El pasador 37 encajaría en un alojamiento (39) si no fuera por un condorcillo (40) que lo impide.

Antes de introducir el proyectil en el mortero, se debe seleccionar el sistema de funcionamiento de la espoleta, girando la nariz a la posición deseada y haciendo coincidir las marcas. Posteriormente se extraer el pasador 43 y se introduce el proyectil.

Una vez lanzado el proyectil el pasador 37, por acción de la inercia se introduce en la oquedad 39, liberando el tornillo 35, que por la acción del muelle 42 sale despedido liberando la pieza 34 que se mueve empujada por el muelle 36, alineándose el percutor y dando continuidad al tren de fuego.

Cuando la granada impacta contra el suelo, el pasador 25 se rompe, provocando que la pieza en forma de U (20) que porta los percutores se desplace, hiriendo los percutor los pistones, y dependiendo del funcionamiento elegido, desencadenar la reacción explosiva instantáneo o con retardo.

Fig. 1 is a longitudinal sectional view of the improved fuse.

Fig. 2 is a similar view taken at right angles to Fig. 1.

Fig. 3 is a sectional view on the line 3-3 of Fig. 2 and

Fig. 4 is a fragmentary view in side elevation of a portion of the fuse.

 The fuse comprises a body 5 adapted to be screwed into a prepared opening in a projectile. The front end of the body is provided with an opening 6 for receiving the stem 7 of a nose 8 having an annular shoulder 9 seating on the rim 10 of the body. The stem 7 is formed with an annular groove il for receiving the inner ends of a pair of pins 12-12 secured in the body 5 and retaining the nose in the body.

 The nose carries two elements of firing mecha­nisms positioned diametrically opposite each other. One consists of a primer 13 and a long flash passage 14 for affording instantaneous ac­tion and the other consists of a primer 15 and a delay train l6 for affording delay action. The elements are each retained in place by means of a plug 17 having an aperture 18.

 A cavity 19 in the forward end of the nose houses a cup-shaped striker 20. A pair of dia­metrically opposite firing pins 21-21 are in­serted through the base of the striker and each has an enlarged head 22 fitting in a recess 23 in the base of the striker. The points of the fir­ing pins are disposed in the apertures 18 of the plugs 17. A plug 24 fitting in the striker re­tains the firing pins in place and a shear pin 25 passing through the nose 8, striker 20 and plug 24 holds the plug in the striker and maintains the striker in the unarmed position.

 A pair of conical recesses 26-26 are provided in the annular shoulder 9 of the nose and are disposed on the diametrical line of the firing pins 21 and primers 13 and 15- The recesses 26 are adapted to be selectively engaged by a latch con­sisting of a ball 27 projecting from the rim 10 of the body and normally urged outwardly by a spring 28. The ball and spring are disposed in a recess 29 in the body.

 In this manner the nose of the fuse may be re­leasably held in either of two positions of ad­justment with one or the other of the firing mechanisms in communication with a flash pas­sage 30 in the body that leads to a detonator 31. An indication of the setting of the nose is af­forded in a well known manner by appropriate inscriptions 32, one being shown in Fig. 4, placed on the exterior of the nose and registerable with a mark 33 on the exterior of the body.

 The detonator 31 is carried in a transversely movable slide 34 normally held out of line with the flash passage 30 by means of a bolt 35 and movable into alignment therewith, upon removal of the bolt, by means of a spring 36.

 The bolt is held in the path of movement of the slide by means of a pin 37 inserted in an aperture 38 in the inner end of the bolt. The lower end of the pin 37 is held in the mouth of a cup-shaped plug 39 by means of a socket mem­ber consisting of spaced ribs 40 having lips 41 engaging the rim of the plug 39.

 On set-back the pin 37 moves rearwardly out of engagement with the bolt and deforms the lips of the socket member. The bolt when withdrawn is ejected from the body by a spring 42. A pin 43 passing through the body 5 and the pin 37 serves to hold the pin immovable in storage and transportation and is removed prior to loading the projectile in a gun or mortar.

 The booster charge 44 in the rear end of the body 5 has a column 45 disposed in alignment with the detonator when in armed position.

 Before loading the projectile in a mortar the fuse is adjusted to give instantaneous or delay action according to the nature of impact de­sired by rotating the nose 8 until the appropriate inscription 32 registers with the mark 33.

 Upon firing the projectile the pin 37 sets back releasing the bolt  35 which is ejected by its spring 36. The slide 34 is then free to be moved to armed position disposing the detonator 31 in line with the flash passage 30.

 On impact the striker 20 is driven inwardly causing both of the firing pins to set of their corresponding primers. Only the primer that is in alignment with the flash passage 30 can trans­mit ignition to the detonator.

I claim.

1. In a fuse, a body having a cavity in its forward end and a flash passage in communica­tion therewith, a nose having an annular shoulder seating on the body and provided with apertures, a reduced portion on the nose disposed in the cavity in the body and formed with an annular groove, pins carried by the body and disposed in the groove, a spring-pressed ball in the body selectively engageable with the apertures in the

shoulder of the nose, a pair of firing pins mount­ed in the nose for unitary longitudinal move­ment, a pair of explosive trains carried by the nose in line with the firing pins and selectively positionable in line with the flash passage in the body upon rotation of the nose.

 2. In a fuse, a body having a flash passage, a nose rotatably mounted on the body, means for selectively holding the nose in positions of ad­justment, a pair of firing pins mounted in the nose for longitudinal movement, an instantane­ous and a delay explosive train carried by the nose in line with the firing pins, and selectively positionable in line with the flash passage in the body upon rotation of the nose.