1. A detonating fuse for use in combination with an explosive projectile and comprising: a firing pin mounted for longitudinal movement; a primer-mounting rotor for supporting a primer mechanism of an explosive charge; said rotor being mounted for movement between: a safety position wherein firing engagement between said primer and said firing pin is prevented, and a firing position wherein firing engagement between said primer and said firing pin is permitted; biasing means adapted to bias said firing pin from a rest position to a firing position within said rotor; a safety nut being rotatably mounted around said firing pin; drive means, including a centrifugal strip, being attached to said safety nut for imparting rotation thereto; a safety element being threadably connected to said safety nut and being longitudinally shiftable along said firing pin, in response to rotation of said safety nut, between: a first position wherein said safety element engages a stop recess of said rotor to hold said rotor iN its safety position, and a second position wherein said safety element and said rotor are out of stopping engagement; a nut-locking mechanism being movable between: a locking position in which it operatively engages and prevents rotation of said safety nut, and a release position to which it is movable by centrifugal force so as to release said safety nut for rotation; a core member mounted for rotation around said firing pin and including first and second extensions; said first extension having means for: securing said nut-locking mechanism in its locking position, and freeing said nut-locking mechanism, in response to a predetermined rotational movement of said core member, to permit movement thereof to its release position; a restraining mechanism located adjacent said biasing means and being movable between: a restraining position wherein said biasing means is prevented from moving said firing pin to its firing position, and a release position wherein said biasing means is free to move said firing pin to its firing position; a movable nut being threadably secured to said second extension and being mounted thereon for non-rotatable, longitudinal shifting movement along said firing pin, in response to rotation of said core member, between: a first position in which said restraining mechanism is held in its restraining position, and a second position in which said restraining mechanism is free to move to its release position; a draw spring being operatively connected to said core member to cause rotation thereof; and timer means connected to said core body to regulate the rate of rotation of said core member; rotation of said core member by a predetermined amount, for releasing said nut locking means, being required to enable said projectile to be detonated.

14. A detonating fuse for use in combination with an explosive projectile and comprising: a firing pin mounted for longitudinal movement; primer-mounting means for supporting a primer mechanism of an explosive charge; said primer-mounting means being mounted for movement between: a safety position wherein firing engagement between said primer and said firing pin is prevented, and a firing position wherein firing engagement between said primer and said firing pin is permitted; biasing means adapted to bias said firing pin from a rest position within said primer-mounting means; a safety nut being rotatably mounted around said firing pin; drive means attached to said safety nut for imparting rotation thereto; a safety element being threadably connected to said safety nut and being longitudinally shiftable along said firing pin, in response to rotation of said safety nut, between: a first position wherein said safety element engages a stop portion of said primer-mounting means to hold said primer-mounting means in its safety position, and a second position wherein said safety element and said primer-mounting means are out of stopping engagement; a nut-locking mechanism being movable between: a locking position in which it operatively engages and prevents rotation of said safety nut, and a release position to which it is movable by centrifugal force so as to release said safety nut for rotation; a core member mounted for rotation around said firing pin and including first and second extensions; said first extension having means for: securing said nut-locking mechanism in its locking position, and freeing said nut-locking mechanism, in response to a predetermined rotational movement of said core member, to permit movement thereof to its release position; a restraining mechanism locaTed adjacent said biasing means and being movable between: a restraining position wherein said biasing means is prevented from moving said firing pin to its firing position, and a release position wherein said biasing means is free to move said firing pin to its firing position; a movable nut being threadably secured to said second extension and being mounted thereon for non-rotatable, longitudinal shifting movement along said firing pin, in response to rotation of said core member, between: a first position in which said restraining mechanism is held in its restraining position, and a second position in which said restraining mechanism is free to move to its release position; a draw spring being operatively connected to said core member to cause rotation thereof; and timer means connected to said core body to regulate the rate of rotation of said core member; rotation of said core member by a predetermined amount, for releasing said nut locking means, being required to enable said projectile to be detonated.

15. A detonating fuse for use in combination with an explosive projectile and comprising: a firing pin mounted for longitudinal movement; primer-mounting means for supporting a primer mechanism of an explosive charge; said primer-mounting means being mounted for movement between: a safety position wherein firing engagement between said primer and said firing pin is prevented, and a firing position wherein firing engagement between said primer and said firing pin is permitted; biasing means adapted to bias said firing pin from a rest position within said primer-mounting means; a safety nut being rotatably mounted around said firing pin; drive means attached to said safety nut for imparting rotation thereto; a safety element being threadably connected to said safety nut and being longitudinally shiftable along said firing pin, in response to rotation of said safety nut, between: a first position wherein said safety element engages a stop portion of said primer-mounting means to hold said primer-mounting means in its safety position, and a second position wherein said safety element and said primer-mounting means are out of stopping engagement; a nut-locking mechanism being movable between: a locking position in which it operatively engages and prevents rotation of said safety nut, and a release position to which it is movable by centrifugal force so as to release said safety nut for rotation; a core member mounted for rotation around said firing pin and including first and second extensions; said first extension having means for: securing said nut-locking mechanism in its locking position, and freeing said nut-locking mechanism, in response to a predetermined rotational movement of said core member, to permit movement thereof to its release position; a restraining mechanism located adjacent said biasing means and being movable between: a restraining position wherein said biasing means is prevented from moving said firing pin to its firing position, and a release position wherein said biasing means is free to move said firing pin to its firing position; a movable nut being threadably secured to said second extension and being mounted thereon for non-rotatable, longitudinal shifting movement along said firing pin, in response to rotation of said core member, between: a first position in which said restraining mechanism is held in its restraining position, and a second position in which said restraining mechanism is free to move to its release position; a draw spring being operatively connected to said core member to cause rotation thereof; and timer means connected to said core body to regulate the rate of rotation of said core member; said nut-locking means including: a safety lever being pivotally mounted at one end for movement from said rest position to said release position in respOnse to centrifugal force; said safety lever having first and second recess portions at its other end; said first recess portion encompassing said safety nut while in the rest position of said safety lever to hold said safety nut against rotation; said first extension of said core member being provided with first and second stop surfaces; said second recess portion of said safety lever encompassing said first extension when said safety lever is in its rest position; a lug being provided on said safety lever and projecting into said second recess portion; said first stop surface and said lug being arranged such that pivotal movement of said safety lever into its release position is prevented by engagement of said first stop surface and said lug; rotation of said core member by a predetermined amount causing said first stop surface to be moved to a position enabling said safety lever to be swung to its release position; said second recess portion further including a notch; said notch and said second stop surface being arranged such that rotation of said core member within said second recess portion causes said second stop surface to engage said notch, in the absence of a force tending to move said safety lever to its release position; said timing means including: a gear mounted for rotation on said core member; a rotatably mounted gear wheel, a drive means drivingly interconnecting said gear wheel to said gear, and rotatable anchor means mounted for engagement with said gear wheel to regulate the rotation of said gear wheel; said anchor means including means for securing said anchor means and said core member against rotation and being movable, in response to centrifugal force, to a position releasing said anchor means and said core member for rotation by said draw spring; said restraining mechanism including: at least one swingable lever pivotally mounted externally of said firing pin; said swingable lever including an arm which, in an inwardly swung position of said swingable lever, projects into a bore provided in said movable nut, to define the restraining position of said restraining mechanism, said arm and said movable nut being arranged such that, in response to a predetermined longitudinal shifting of said movable nut, said arm is freed from said bore to enable said swingable lever to pivot under the influence of centrifugal force to an outwardly swung position to define the release position of said restraining mechanism; a guide element being arranged to encompass a non-circular outer periphery of said movable nut to prevent rotation of said movable nut relative to said second extension of said core member; rotation of said core member by a predetermined amount, for releasing said nut-locking means, being required to enable said projectile to be detonated.