Patent Publication Number: US-3877379-A

Title: Multipurpose percussion fuse

Description:
United States Patent Losfeld Apr. 15, 1975 [54] MULTIPURPOSE PERCUSSION FUSE 5 1,362 8/1947 United Kingdom l02/81.6  
 [76] Inventor: Christian Losfeld, 13/15 rue Thiebault, Charenton, France, Primary Examiner-Robert F. Stahl 94220 [22] Filed: Aug. 29, 1973 [57] ABSTRACT [21] Appl. No.: 392,674  
  This percussion fuse comprises essentially a fuse of the ercussion or im act t e incor oratin a rimer, a [30] Forelgn Apphcatmn Pnonty Data Striker, a massivz meiifber ada pted ti cfuse said Sept. 1, 1972 France 72.31038 Striker to hit Said primer by inertia when the impact shock takes place, said massive member being freely [52] US. Cl 102/74; 102/81.6 bl i a&#34; direction; a pin locking Said primer and [51] hit. C1. F42C 9/14 Striker in their relative storage position is urged by [58] Field of Search 102/73, 74, 72, 76, 78, Spring means to its release or ejection position, this 102/79 816, 70 urging action being counteracted by a safety device comprising in turn three separate elements, namely a [56] References cued cap known per se which covers and protects said fuse, UNITED STATES PATENTS detachable ring and a weighted tape wound around 2,100,698 11/1937 Morncr lO2/8l.6 said fuse for counteracting the ejection of Said P 3,430,567 3/1969 Losfeld 102/72 this ring surrounds said weighted tape to prevent the 3,788,230 1/1974 Losfeld 102/74 unwinding.  
  FOREIGN PATENTS OR APPLICATIONS 16 Claims 17 Drawing Figures 954,131 I/l956 Germany 102/73 R PATENTEDAPRlSlQYS 3,877 379 SHEET 1 [If 2 PATENTEUAPR 1 51975 3,877, 379  
 SHEET 2 0f 2 MULTIPURPOSE PERCUSSION FUSE BACKGROUND OF THE INVENTION In the field of fuses acting by percussion when they strike the target, thus producing a shock. many devices capable of operating on a well-defined projectile and for a well-defined purpose or use are already known.  
  However, no fuse capable of operating on miscellaneous projectiles utilized under very different conditions is known so far.  
 SUMMARY OF THE INVENTION It is the essential object of this invention to provide a fuse adapted for use indifferently in hand-grenades,  
 gun-fired grenades and also grenades jettisoned from BRIEF DESCRIPTION OF THE DRAWINGS These essential features will appear clearly as the following description proceeds with reference to the at tached drawings illustrating diagrammatically by way of example various forms of embodiment of the invention. In the drawings:  
 FIG. I is an axial section of the fuse;  
  FIG. 2 is a separate view of the tape. plummet and ring;  
 FIG. 3 is a modified view of the ring;  
 FIG. 4 is a view showing the arming rod and its spring means:  
 FIG. 5 is an axial section of the nose tip;  
 FIG. 6 isa view showing the detachable strip;  
  FIG. 7 is a fragmentary axial section showing the fuse equipped with its arming sheath;  
  FIG. 8 is another axial section showing the two firing members after the complete rotation of one of these members;  
  FIG. 9 is a cross-section showing the members of FIG. 8, the section being taken through the axis of the arming pin;  
  FIG. 10 is an axial section showing the same members. one of these members being partially rotated;  
  FIG. 11 is a crosssection showing the members of FIG. 10, the section being taken through the axis of the arming pin;  
  FIG. 12 is an external view of the fuse equipped with a detachable safety ring;  
  FIG. 13 is another external view of the fuse equipped with a cap (shown in section);  
  FIG. 14 is a fragmentary view of the fuse with its plummet provided with a lateral projection;  
  FIG. 15 is a fragmentary plane view from above of the members of FIG. 14;  
  FIG. 16 is a view showing a modified embodiment of the plummet with a lateral projection; and  
  FIG. 17 is a view showing another modified form of embodiment of the plummet with a lateral projection.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT The fuse 1 comprises a primer 2 mounted on a sliding tube, a striker 3 mounted on a sliding sleeve, a massive member 4 having a multidirectional inertia. a tip 5, an arming pin or rod 6 urged both by a long spring 7 and by a short spring 8.  
  A tape 9 is wound around the fuse in order to keep the arming rod 6 in the fuse. This wound tape 9 is tightly held in a lead plummet l0 fitting exactly against said tape 9 above the frustoconical ramp ll of the fuse.  
  The end 91 of tape 9 may be attached to a ring 14 positioned on top of the fuse and surrounding same without interferring with the fitting of the cap 13. This ring 14 may be made of flexible material and discontinued at 141 by a cut diametrally opposite to the end 91 of tape 9.  
  A detachable strip 12 surrounding the plummet l0 and tape 9 comprises three sections; namely a first section 121 permitting of forming one winding turn, a second section 122 for partially covering this winding and provided with an adhesive coating, and finally a third section 123 constituting a pull-out lug.-  
 A cap 13 is adapted to be fitted at will to the fuse.  
  The springs 7 and 8 are coil springs disposed coaxially to each other.  
  The tip 5 bearing against the inertia element 4 comprises laterally a projecting flange 51 retaining the fuse tip; the base 52 of this tip which bears on the inertia weight 4 is of frustoconical configuration. like its lateral surface 53 and the outer edge 511 of its flange 51.  
  For operating the fuse, the cap 13 is firstly removed and the strip 12 is then detached just before throwing the fuse, by simply pulling the lug 123 thereof. This strip 12 comprises only a small section 122 coated with adhesive, so that it can be removed without having to overcome any undue resistance.  
  For hand-throwing, the shaped sheath I0 is firstly released by producing a slight movement of the thumb (possibly after allowing the ring 14 to hang). By inertia, the plummet 10 during its movement will cause the unwinding of tape 9, thus permitting the ejection of the arming pin 6; this pin 6 is urged by the stronger spring 8 acting during a short time and also by the weaker but longer-acting spring 7, the latter preventing a too sudden arming which might be dangerous in case the priming composition had spread within the fuse.  
  To fire the fuse by means of a gun, the plummet 10 is not released and it is also unnecessary to allow the ring 14 to hand if the latter is flexible and open at 141. When the shot is started, the plummet I0 is about to be thrown by inertia on the ramp 11 and will loose its shape and pull the tape 9, so that the latter is unwound to permit the ejection of the arming pin 6.  
  To jettison the fuse from an aircraft. it is only necessary to insert a finger in ring I4 so that the tape 9 will be unwound during the fall of the projectile.  
  Thus, this safety system operates efficiently under all circumstances.  
  A sheer percussion is obtained irrespective of the manner in which the fuse is hit, due to the action of tip 5, even if the projectile falls in a horizontal position, at low speed, on a mattress of vegetable elements. In fact, this tip operates not only by thrusting back when the fuse falls on its nose or head-on (as generally observed when firing the fuse with a gun) but also by tipping and sliding. when the fuse falls on one side (as frequently observed in hand-throwing and when jettisoning from an aircraft). and by gravity, when the fuse drops in an upright position (a frequent occurrence in handthrowing and jettisoning). The tipping and sliding movement of the tip is due to the frustoconical shape of its bearing surfaces.  
  In a first modified embodiment shown in FIG. 7. the arming pin or rod 6 is surrounded by the sheath 16 extending partially or completely through the primercarrying tube 21 and the striker-carrying sleeve 31. Thus, the pin is urged firstly by the short and strong spring 15 reacting against the end of sheath l6 and housed within the extension 161 of the sheath. The longer and weaker spring 17 reacts against the fuse l and urged the flange 162 of extension 161 of sheath 16.  
  After the weighted tape 9 is unwound. the pin 6 is ejected by the force of the stronger spring 15, and since this force is applied at the same time against the end portion of sheath 16, the latter is held in its initial position as long as this force exceeds or equals that of the weaker spring 17. Then the sheath 16 is ejected by the urge of the spring 17. Thus. the presence of sheath l6 protracts the time necessary for arming the fuse and the safety length of the trajectory. This time may be further increased by increasing the length of spring 15 and sheath 16, thus improving the telescopic effect.  
  In a second modified form of embodiment illustrated in FIGS. 8, 9,10 and 11, the two ends 181 and 182 of the spacer spring 18 penetrate into the primer-carrier tube 21 and into the striker-carrier sheath 31, respectively. When assembling the component elements of the fuse. a torsional pre-stress is imparted to spring 18 when the hole 311 of sleeve 31 is aligned with that 211 of tube 21. and when the pin 6 has penetrated into these two spaces 311 and 211.  
  After ejecting the pin 6 or sheath 16, the spring 18. by expanding. causes the striker-carrier 31 to rotate and the two aforementioned holes 311 and 211 to become misaligned, thus closing the fuse orifices communicating with the surrounding atmosphere and preventing any undesired loss of ignited gas from the pimer or of smoke-producing gas from the grenade body.  
  The rotation of the sleeve or primer-carrier 31 may take place in two steps. so that during the ejection of pin 6 or sheath 16 the inner hole of tube 21 remains constantly isolated from elements both externally and internally of the fuse. such as water and/or fire. To this end, the hole 312 is ovalized by forming a notch in the sleeve 31 to permit the partiel rotation of this sleeve when the end of pin 6 or sheath 16 has left the space 311; the complete rotation of said sleeve 31 takes place when the end of pin 6 or sheath 16 has left the hole 312.  
  In a third modified embodiment illustrated in FIGS. 12 and 13 the detachable ring 22 covers partially the front end of the fuse and surrounds the weighted tape 9 along one fraction of its height. This ring is cut at 221 so that the pin 6 be ejected even if the retachable ring remains in position on the fuse. This ring may rotate around the fuse axis so as to produce automatically the positioning of a fuse adjustment member, such as a se lector controlling the impact and or time fire of the fuse, means controlling the instantaneous and/or delayaction timing, safety lock, etc. Finally, a cap 23 may be used for protecting the fuse, and the strip 12 of FIG. 6  
 may cover completely the lower portion of the fuse and make it water-tight.  
  Thus. the lower portion 222 of ring 22 surrounds the weighted tape 9 and prevents same from being unwound. even in case of strong shocks, whether ahead or laterally. On the other hand, in case of strong shocks from the rear. as in the case of grenades fired by means of a gun, the weighted tape 9 can be unwound by sliding longitudinally, the plummet 10 being projected by inertia on the frustoconical ramp 11 of the fuse at the start of the shot. and sliding along said ramp so as to be pushed outwards and thus cause the tape to be unwound. Under these conditions. when firing with a gun, the detachable ring may remain in position before firing. the plummet 10 and tape 9 being adapted to slide under the lower portion 222 of this ring. Before handthrowing. the ring 22 must be removed. Therefore. this ring maintains the fuse in a safety condition even after removing the cap 13. until the fuse is fired with a gun. this ring further improving the aerodynamic behavior of the fuse during its trajectory in the case of a gunfired grenade.  
  ln a fourth embodiment illustrated in FIGS. 14, 15. 16 and 17, the plummet 10 weighting the tape 9 is formed with a lateral projection 102 having its end inserted into the notch 24 formed in the fuse at the end of the winding of said weighted tape 9. This projection 102 may be an integral part of plummet 10 or an insert fitted therein; if desired. it may comprise a small stop 103 or an extra-thickness 104 limiting the insertion of said projection 102 into the notch 24.  
  The function of said projection 102 is to prevent the plummet 10 from loosing its shape. being loosened and thus permitting an incipient unwinding of the tape in case of strong head-on or lateral shocks. When firing the grenade or fuse with a gun. this projection 102 will not prevent the sheath from being thrown by inertia along the frustoconical ramp 11 and urged outwards. in order to unwound the tape. When throwing the fuse by hand. it is only necessary to release the plummet 10 by applying an oblique movement thereto thus enabling the projection 102 to be pulled out said notch 24; it is still possible at the last moment to renounce the throwing of a hand-grenade and to refit the plummet 10 over the tape winding 9, the projection 102 being re-inserted into its notch 24 in this case.  
  Although various embodiments of the invention have been shown and described herein. it will readily occur to those conversant with the art that other modifications and changes may be brought thereto without departing from the basic principles of the invention as set forth in the appended claims.  
 What 1 claim as new is:  
  1. A percussion fuse comprising a primer. a striker, a massive member adapted to cause said striker to hit said primer when the impact shock takes place, said massive member being freeely movable in all directions, a&#39;pin locking said primer and striker in their relative storage position, a mechanism constantly tending to eject said pin. and a safety device counteracting the ejection of said pin, said fuse being characterized in that said safety device comprises three separate parts, namely a cap, covering and protecting said fuse. a detachable ring. and finally a weighted tape wound around the fuse for counteracting the ejection of said pin, said detachable ring surrounding said weighted tape and preventing the unwinding thereof.  
  2. A fuse according to claim 1, characterized in that said detachable ring comprises a three-sectioned strip of which the first section permitting of making a complete revolution about the fuse. the second section provided with adhesive means for causing same to adhere to one portion of said first section. and a third section acting as a tear-off lug.  
  3. A fuse according to claim 1, characterized in that said detachable ring is rotatably mounted and that its axial rotation draws along the positioning of a member controlling the fuse operation.  
  4. A fuse according to claim 1. characterized in that said detachable ring does not covers the complete height of said weighted tape so that when the ring is left in position on the fuse said weighted tape can unwound itself by sliding longitudinally thereon. and that said ring is cut to permit the ejection of said pin.  
  5. A fuse according to claim 1, characterized in that a deformable plummet surrounds the end of said weighted tape and that the fuse body comprises at its rear portion a frustoconical ramp slidably engageable by said plummet when said plummet is subjected to the force of inertia produced by the shooting of the projectile equipped with this fuse. whereby said plummet is pushed outwards and causes said tape to be unwound.  
  6. A fuse according to claim 1, characterized in that a deformable plummet is tightly fitted on the end portion of said weighted tape and comprises a lateral projection inserted into the front portion of the fuse body when said weighted tape is wound.  
  7. A fuse according to claim 1. characterized in that a ring adapted to be laid on the front end of the fuse. under the cap thereof. is secured to the end of said weighted tape.  
  8. A fuse according to claim 1, characterized in that two springs surround said pin and are adapted to act in succession thereon. said springs comprising a first. short and relatively powerful spring for starting the pin ejection and a second. longer and relatively weaker spring. for completing this ejection.  
  9. A fuse according to claim 1. characterized in that said primer and striker are so arranged that their relative position is modified by the axial rotation of one of them after the ejection of said pin.  
  10. A fuse according to claim 9, characterized in that a spring. having its ends integral with said primer and striker respectively constantly urges said two members for relative rotation about their common axis. said pin preventing this rotation.  
  11. A fuse according to claim 9. characterized in that means are provided for permitting the relative rotation of said two members during the sliding of said pin through the mobile members of the fuse.  
  12. A fuse according to claim 1. characterized in that a tip is retained by its projecting flange. in the front part of the fuse. on said massive member. that said tip becomes axialy and lateraly mobile by the release of said massive member due to the pin ejection. and that the lateral surfaces of said tip are frustoconical.  
  13. A percussion fuse comprising a primer. a striker. a pin for locking said primer and striker in their relative storage position. a mechanism constantly tending to eject said pin. and a safety device. said fuse being characterized in that two springs surround said pin and are adapted to urge said pin in succession. a first spring starting the pin ejection and the second spring completing said ejection.  
  14. A fuse according to claim 8, characterized in that a mobile sheath surrounds said pin. said first spring bearing against one end of said sheath.  
  15. A percussion fuse comprising a primer. a striker. a massive member adapted to cause said striker to hit said primer during the impact shock said massive member being furtermore freely movable in all directions. and a safety system. said fuse being characterized in that a tip is maintained in the front part of the fuse on said massive member. that said tip becomes axialy and lateraly mobile by the release of said massive member due to the withdrawal of said safety system. and that the lateral surfaces of said tip have a frustoconical configuration.  
 16. A fuse according to claim 13. characterized in that a mobile sheath surrounds said pin. said first spring