Patent GB-811089-A (GB)
Title: Improvements in or relating to instantaneous and timelag percussion fuzes for gun and small-arm projectiles
IPC: F42C15/184
Filed: 1957-04-09
Abstract: 811,089. Projectile fuzes. LOSFELD, A., and ROUSTANT, M. April 9, 1957 [April 11, 1956; Dec. 22, 1956], No. 11615/57. Class 9(1) A direct action percussion fuze for projectiles which may be arranged to operate after a given delay has a body 1 consisting of two parts 1a, 1b locked together by a peg 90, the part 1a being bored axially to house a primer 86 for a detonator 88. In the upper end of the part 1a is a guide groove 2 stopped by a peg 3 and surrounded by an annular flange 5 in which is an aperture 48. The upper end of the part 1b has notches 25 to engage radial lugs of a locking device 26, Fig. 4. Outside the flange 5 within the part 1b is an annular race with apertures 4 to engage balls housed in the lower face of a rotatable barrel 10 from which a pin 11 projects into the groove 2. The flange 5 engages a circular groove 5a in the barrel. A diametral slot 14 in the barrel houses three slides 68, 78, 67 carrying ignition means, the slides 68, 67, which carry a primer 69 and a relay 71 respectively, being locked together while the slide 78 houses a delay element 79. Slide 68 is recessed to house a bolt 73 pressed against the inner surface of the barrel by a spring, while the slide 78 carries a similar stop bolt 81 aligned with bolt 73, both slides being bored axially to receive the tip of the firing pin 31 which sets back due to inertia when a projectile fitted with the fuze is fired from a gun. A spring 72 thrusts the slide 67 against the flange 5 and a spring 80 urges the slide 78 into engagement with a rod 77 extending radially into an opening in the barrel 10, the delay 79 then being aligned with the primer 69 and the relay 71. A stud 58 protected by a cap 59 extends through the part 1b into contact with the barrel and can be adjusted to bring a cavity therein into alignment with the rod 77 when the barrel has rotated through an angle which brings the slide 67 opposite the aperture 48. The delay is then aligned with the primer 69 and relay 71 along the fuze axis. A driving spring 27 has one end engaged in the part 1a and the other end in the barrel 10. The top of the barrel carries a bearing ring 28 supporting a spring 29, which urges an arming ring 30 against the head of the striker 31 over which a washer 34 is secured in the fuze cap 35. The ring 30 may be locked by means of a stud 37 having a flat shank 38 engaged in a circular hole 39 communicating with a slot 40 slightly wider than the thickness of the shank. A peg 44 projecting from the cap 35 acts as a stop for the stud. Before firing a projectile fitted with the fuze a cap 42 covering the studs 37 is torn off and the stud is turned to release the ring 30. For instantaneous operation the cap 59 is left intact and on firing the ring 30 hits the lugs of the device 26 and so releases the barrel 10. While the projectile is accelerating the barrel is pressed against the body 1 due to its inertia and so prevented from rotating. In addition the pin 31 locks the ignition means. As the projectile decelerates the barrel 10 rotates until stopped by the peg 3 and thus brings the ignition means into alignment with the gap 48. The striker is moved forward by its spring 29 and releases the ignition means which is then moved by spring 72 until the primers 69, 71 are aligned with the pin 31, the delay carrier being held out of alignment by the rod 77. The fuze is then armed and on impact the pin 31 will initiate the primer 69, the flash passing through the axial passage in the delay carrier to the primer 71. For delay operation, the cap 59 is torn off and the stud 58 rotated' to bring its recess into line with the rod 77, so that after the barrel has rotated the rod 77 moves into the recess and allows the delay carrier to slide transversely bringing the delay 79 into alignment with the primers 69, 71 and the pin 31. In the inoperative position the primers and the delay are in communication through the groove 2 and an opening 92 with the annular space housing the spring 27, so that if accidental ignition occurs the gases can expand. Expansion grooves are also formed in the outer surface of the barrel 10. An inertia weight 83, e.g. lead, housed in the carrier 67 moves out when the projectile is rotated. A metal washer 84 is used to stiffen the device 26 and so prevent re-locking of the barrel. Primer 69 may slide into a recess 63, so that the fuze operates by inertia should the striker not be driven inwards on impact.