Claims
- 1. An impact delay fuse for use in a spin launched explosive shell to delay detonation of the explosive charge of the shell until after impact of the shell with a target, said delay fuse comprising:
- a hollow housing adpated to be positioned in said shell for rotation therewith in a first direction about a shell spin axis when the shell is launched and begins to spin;
- detonation means for detonating the explosive charge of said shell, said detonation means being movable between a loaded position and a detonating position, and being biased toward said detonating position;
- a locking member coaxially mounted within said housing for rotation between a first position and a second position disengaged from said detonator means so that said locking member when in said first position being in engagement with said detonation means so as to maintain said detonator means in said loaded position and said locking member when in said second position being disengaged from said detonation means so that said detonation means is free to be moved to said detonating position; and
- a sensing and firing mechanism for controlling rotation of said locking member between said first and second positions, said sensing and firing mechanism comprising:
- an inertia member within said housing;
- inertia mounting means for mounting said inertia member coaxially within said housing to rotate said inertia member with said housing in said first direction when said shell is launched and to rotate said inertia member in said first direction for a predetermined distance relative to said housing when said shell impacts the target;
- inertia bias means for biasing said inertia member for rotation in a second direction relative to said housing, said second direction of rotation being opposite from said first direction of rotation; and
- coupling means for engaging said locking member with said inertia member for rotation therewith only when said inertia member is rotated in said second direction relative to said housing.
- 2. The impact delay fuse of claim 1 wherein said inertia mounting means comprises:
- bearing means for supporting said inertia member for rotation in said first and second directions relative to said housing, and a stop member on the interior of said housing engagable with a portion of said inertia member to cause rotation of said inertia member with said housing in said first direction when said shell is launched;
- wherein said inertia bias means normally biases said portion of said inertia member against said stop member; and
- wherein said inertia member is movable in said first direction relative to said stop member against said inertia bias means whereby when said housing is subjected to spin deceleration upon impact with the target said inertia member will rotate in said first direction against said inertia bias means for said predetermined distance relative to said housing.
- 3. The impact delay fuse of claim 2 wherein said inertia mounting means further comprises:
- means for supporting said inertia member for axial movement of said inertia member relative to said housing upon impact of said shell with said target, a camming member on one of said housing and said inertia member, and a corresponding camming surface on the other of said housing and inertia member for camming said inertia member to rotate in said first direction relative to said housing in response to axial movement of said inertia member relative to said housing.
- 4. The impact delay fuse of claim 2 or 3 wherein said inertia biasing means comprises a spiral spring engagable with said inertia member and with said housing.
- 5. The impact delay fuse of claim 1 wherein said inertia mounting means comprises:
- means for supporting said inertia member for axial movement of said inertia member relative to said housing upon impact of said shell with said target, a camming member on one of said housing and said inertia member, and a corresponding camming surface on the other of said housing and said inertia member for camming said inertia member to rotate in said first direction relative to said housing in response to axial movement of said inertia member relative to said housing.
- 6. The impact delay fuse of claim 3 or 5 wherein said means for supporting said inertia member for axial movement comprises a spring member disposed axially between said inertia member and an axial fce of said housing for biasing said inertia member in an axial direction away from the axial component of movement of said shell upon launching of said shell so that said inertia member is axially movable in the direction of axial movement of said shell against the bias force of said spring member when said shell impacts with the target.
- 7. The impact delay fuse of claim 3 in which said cam surface is disposed on said inertia member and in which said cam member is fixably mounted with respect to said housing.
- 8. The impact delay fuse of claim 5 in which said cam surface is disposed on said inertia member and in which said cam member is fixably mounted with respect to said housing.
- 9. The impact delay fuse of claims 7 or 8 in which said housing includes an axially extending guide sleeve coaxially mounted with respect to said spin axis of said housing, said cam member being disposed radially outward from said guide sleeve, and wherein said inertia member is annular and coaxially mounted with respect to said guide sleeve with said camming surface located on the inner annular surface of said inertia member.
- 10. The impact delay fuse of claim 1 wherein said coupling means comprises a ratchet wheel having inclined teeth and a ratchet pawl, said ratchet wheel being fixably mounted on one of said inertia member and said lock member, and said ratchet pawl being mounted on the other of said inertia member and said lock member so that said ratchet wheel and said ratchet pawl move relative to one another when said inertia member is rotated in said first direction with respect to said housing and so that said ratchet pawl and ratchet wheel are engaged to rotate together when said inertia member is rotated in said second direction relative to said housing.
- 11. The impact delay fuse of claim 10 in which said ratchet wheel is disposed on said locking member and wherein said ratchet pawl is disposed on said inertia member.
- 12. The impact delay fuse of claim 1 wherein said detonation means comprises a detonator fixably supported relative to said housing, a firing pin axially movable relative to said housing, and a firing pin spring for biasing said firing pin towards said detonator, said locking member when in said first position locking said firing pin in an axial position spaced from said detonator.
- 13. The impact delay fuse of claim 12 wherein said detonation means further includes an annular guide sleeve coaxially mounted in said housing and surrounding said movable firing pin, a radial opening in the side wall of said guide sleeve, and a locking ball in said opening; wherein said firing pin includes an annular groove engagable by said locking ball; and wherein said locking member comprises an annular locking sleeve coaxially supported relative to said firing pin and said guide sleeve, said locking sleeve having a cylindrical inner side wall and a recessed opening in a portion of said cylindrical inner side wall, said cylindrical inner side wall of said locking sleeve when said locking sleeve is in said first position holding said locking ball in engagement in said annular groove of said firing pin to prevent axial movement of said firing pin, and said locking sleeve when in said second position having said recessed opening aligned with said opening in said guide sleeve so that said locking ball is free to move radially outward into said recessed opening to release said firing pin.
- 14. The impact delay fuse of claim 1 further including a time delay device for preventing movement of said inertia member relative to said housing for a predetermined period after launch of said shell to prevent premature detonation of said shell.
- 15. the time delay device of claim 14 wherein said time delay device comprises:
- a rotatable rotor coaxially mounted within said housing and adapted to rotate relative to said housing between a start position and an armed position;
- means responsive to the rotation of said housing for rotating said rotor from said start position to said armed position; and
- rotation prevention means on said rotor for preventing rotation of said inertia member relative to said housing until said rotor is in said armed position.
- 16. The impact delay fuse of claim 15 wherein said housing includes a cover adjacent to said rotor, said cover including at least one radially extending groove therein; wherein said rotor includes at least one arcuate groove in the surface thereof facing said cover; and wherein said means for rotating said rotor comprises a rotatable ball disposed between said radially extending groove of said cover and said arcuate groove of said rotor, one end of said arcuate groove of said rotor being aligned with the innermost end of said radially extending groove of said cover when said rotor is in said start position and the other end of said arcuate groove being aligned with the outermost end of said radial groove when said rotor is in said armed position so that rotation of said housing causes said ball to move radially outward in said grooves to thereby rotate said rotor from said start position to said armed position.
- 17. The impact delay fuse of claim 16 wherein said rotation prevention means comprises:
- an inertia rotor ball;
- an inertia member groove in the axial surface of said inertia member facing said rotor, said inertia member groove having an outer arcuate portion and a radially extending portion, the radially outermost end of said radially extending portion of said inertia member groove communicating with one end of said outer arcuate portion; and
- a rotor groove in the axial surface of said rotor facing said inertia member, said rotor groove having an inner arcuate portion and a radially extending portion, said radially extending portion of said rotor groove extending radially outward from one end of said inner arcuate portion, said radially extending portion of said rotor groove being coextensive with said radially extending portion of said inertia member groove when said rotor is in said armed position, and said inner arcuate portion of said rotor groove being aligned with the radially innermost end of said radially extending portion of said inertia member groove when said rotor is in a position other than said armed position so that said inertia rotor ball is disposed in the radially innermost end of said radially extending portion of said inertia member groove to prevent rotation of said inertia member relative to said housing until said rotor is in said armed position.
- 18. The impact delay fuse of claim 17 further including a plate fixably mounted between said rotor and said inertia member, said plate having a radially extending slot in which said inertia rotor ball is disposed, said radially extending slot being coextensive with said radially extending portion of said inertia member groove when said rotor is in a position other than said armed position and being coextensive with said radially extending portion of said rotor groove when said rotor is in said armed position.
- 19. The impact delay fuse of claim 1 further including means for preventing rotation of said locking member in said first direction relative to said housing and for permitting a predetermined amount of rotation of said locking member in said second direction relative to said housing.
- 20. The impact delay fuse of claim 19 in which said means for preventing rotation of said locking member in said first direction comprises a slot in a portion of said housing, and a pin on said locking member extending axially into said slot, said slot in said housing being arcuate so that said pin is movable in said slot to provide said predetermined amount of rotation of said locking member in said second direction relative to said housing but to prevent movement of said pin in said first direction relative to said housing.
GOVERNMENTAL INTEREST
The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.
US Referenced Citations (5)