Timing mechanism

Claim 2

In a centrifugally operable arming delay mechanism comprising a centrifugally operable rotor rotatable between an initial unarmed position and a final armed position in response to spinning of said mechanism about an axis therein, and first centrifugally operable detent means for preventing rotation of said rotor prior to said spinning but responsive to said spinning to move so as to free said rotor therefrom, the improvement comprising: second centrifugally operable detent means for preventing rotation of said rotor prior to said spinning but responsive to said spinning, when released, to move so as to free said rotor therefrom; and interlock means acting between said first and second detent means for restraining said second detent means until said first detent means has moved to free said rotor therEfrom, and for releasing said second detent means in response to said moving of said first detent means, thereby to permit subsequent freeing of said rotor from said second detend means.

Claim 3

Apparatus in accordance with claim 1, in which said interlock means comprises balance means responsive to rotation of said rotor to oscillate about a pivot axis therein thereby to slow said rotation of said rotor, said balance means extending between said first and second detent means and configured and held by said first detent means prior to said spinning to restrain said second detent means from moving so as to free said rotor from said second detent means, said moving of said first detent means to free said rotor therefrom permitting said balance means to move in response to said rotor thereby permitting said second detent means to move so as to free said rotor therefrom.

Claim 4

Apparatus in accordance with claim 2, in which said pivot axis of said balance means is farther from said axis of spinning than is the center of mass of said balance means.

Claim 5

In a centrifugally operable arming delay mechanism for a projectile which spins about a predetermined spin axis therein after firing of the projectile, and comprising a pivoted balance, a rotor pivoted off-center from its center of mass and from said spin axis so as to rotate, when free, in response to centrifugal forces generated by such spinning of said projectile, toothed means connecting said rotor to said balance to cause said balance to oscillate and to slow said rotation of said rotor, and first centrifugally operable detent means having a first position in which it normally blocks said rotation of said rotor and a second position to which it is operable in response to said spinning in which said rotor is freed of said first detent means, the improvement in accordance with which: said mechanism comprises second centrifugally operable detent means having a first position in which it normally blocks said rotation of said rotor and a second position toward which it is urged by centrifugal forces during said spinning and in which said rotor is freed of said second detent means, said balance means being configured to extend between said first and second detent means and having restraining means thereon for holding said second detent means in said first position thereof despite said urging by said centrifugal forces when said balance means is in one rotational position thereof and for freeing said second detent means when said balance is in a second rotational position thereof, and releasable means for holding said balance means in said first position prior to said spinning and responsive to movement of said first detent means from said first position thereof to said second position thereof to release said releasable means and thereby permit said balance means to assume said second position thereof, whereby said spinning causes said rotor to be freed of said second detent only after said rotor has been freed from said first detent.

Claim 6

In a centrifugally operable arming delay mechanism for a projectile which spins about a predetermined spin axis therein after firing of the projectile, and comprising a pivoted balance, a rotor pivoted off-center from its center of mass and from said spin axis so as to rotate, when free, in response to centrifugal forces generated by such spinning of said projectile, toothed means connecting said rotor to said balance to cause said balance to oscillate and to slow said rotation of said rotor, and first centrifugally operable detent means having a first position in which it normally blocks said rotation of said rotor and a second position to which it is operable in response to said spinning in which said rotor is freed of said first detent means, the improvement in accordance with which: said mechanism comprises second centrifugally operable detent means having a first position in which it normally blocks said rotation of said rotor and a second position toward which it is urged by centrifugal forces during said spinning and in which said rotor is freed of said second detent means, said balance means being configured to extend between said first and second detent means and having restraining means thereon for holding said second detent means in said first position thereof despite said urging by said centrifugal forces when said balance means is in one rotational position thereof and for freeing said second detent means when said balance is in a second rotational position thereof, and releasable means for holding said balance means in said first position prior to said spinning and responsive to movement of said first detent means from said first position thereof to said second position thereof to release said releasable means and thereby permit said balance means to assume said second position thereof, whereby said spinning causes said rotor to be freed of said second detent only after said rotor has been freed from said first detent.

Claim 7

Apparatus in accordance with claim 4, in which said balance means is pivoted about an axis further from said spin axis than is the center of mass of said balance means.

Claim 8

In a centrifugally operated time-delay mechanism for a projectile of the type which spins about a predetermined axis after firing, thereby also to spin said mechanism about a spin axis in said mechanism, and comprising centrifugally operated rotor means and escapement means including a pivoted balance means for resisting and slowing the operation of said escapement means and said rotor means, the improvement according to which said balance means has a pivot axis which is further from said spin axis than is the center of mass of said balance means, whereby centrifugal forces acting on said balance means due to spinning of said mechanism about said spin axis produce a decrease in the rate of rotation of said rotor means.

Claim 9

In a centrifugally operated time-delay mechanism for a projectile of the type which spins about a predetermined axis after firing, thereby also to spin said mechanism about a spin axis in said mechanism, and comprising centrifugally operated rotor means and escapement means including a pivoted balance means for resisting and slowing the operation of said escapement means and said rotor means, the improvement according to which said balance means has a pivot axis which is further from said spin axis than is the center of mass of said balance means, whereby centrifugal forces acting on said balance means due to spinning of said mechanism about said spin axis produce a decrease in the rate of rotation of said rotor means.

Claim 10

Apparatus in accordance with claim 6, in which said escapement means comprises a plurality of teetH integral with said rotor means and said balance means comprises pallet means engaged successively by different ones of said teeth as said rotor means rotates to cause said balance means to oscillate about said pivot axis.

Claim 11

A rotation-responsive runaway-escapement time-delay mechanism, comprising: a support rotatable about a first axis therein; a centrifugally operable rotor pivoted about a second axis displaced from said first axis and having a center of mass displaced from said second axis, whereby rotation of said support about said first axis urges said rotor centrifugally toward an outwardmost angular position in which said center of mass is at its maximum distance from said first axis; balance wheel teeth mechanically connected in torque-transmitting relation with said rotor so as to rotate with rotation of said rotor and so as to respond to torques applied to said teeth to accelerate or decelerate rotation of said rotor toward said outward-most position; and balance means pivoted about a third axis and having a center of mass displaced radially inwardly from said third axis toward said first axis, said balance means comprising pallet means positioned to be engaged by successive ones of said balance wheel teeth as said rotor rotates about said second axis toward said outwardmost angular position so as to oscillate said balance means about said pivot means in response to motion of said teeth and in response to centrifugal force due to rotation of said support, thereby to slow the rotation of said rotor toward said outwardmost angular position.

Claim 12

A rotation-responsive runaway-escapement time-delay mechanism, comprising: a support rotatable about a first axis therein; a centrifugally operable rotor pivoted about a second axis displaced from said first axis and having a center of mass displaced from said second axis, whereby rotation of said support about said first axis urges said rotor centrifugally toward an outwardmost angular position in which said center of mass is at its maximum distance from said first axis; balance wheel teeth mechanically connected in torque-transmitting relation with said rotor so as to rotate with rotation of said rotor and so as to respond to torques applied to said teeth to accelerate or decelerate rotation of said rotor toward said outward-most position; and balance means pivoted about a third axis and having a center of mass displaced radially inwardly from said third axis toward said first axis, said balance means comprising pallet means positioned to be engaged by successive ones of said balance wheel teeth as said rotor rotates about said second axis toward said outwardmost angular position so as to oscillate said balance means about said pivot means in response to motion of said teeth and in response to centrifugal force due to rotation of said support, thereby to slow the rotation of said rotor toward said outwardmost angular position.

Claim 13

In a centrifugally operated time-delay arming mechanism for use in an explosive shell to delay the arming of said shell until after it has been fired and has executed a predetermined number of revolutions of spin about a spin axis extending through said mechanism, said mechanism comprising: a centrifugally operable rotor mounted to pivot about a first axis displaced from said spin axis and having a center of mass displaced from said first axis whereby spinning of said mechanism about said spin axis urges said rotor from an unarmed angular position in which said center of mass is relatively nearer said spin axis toward an armed angular position in which said center of mass is relatively farther from said spin axis; camming teeth on said rotor; and balance means mounted to pivot about a second axis displaced from said first axis and from said spin axis and positioned to oscillate back and forth about said second axis in response to engagement by successive ones of said camming teeth as said rotor moves toward said armed position; the improvement wherein said balance means has a center of mass nearer said spin axis than is said second axis, whereby the oscillations of said balance means are opposed at least in part by centrifugal forces acting on said balance means in response to rotation of said mechanism about said spin axis.

Claim 14

In a centrifugally operated time-delay arming mechanism for use in an explosive shell to delay the arming of said shell until after it has been fired and has executed a predetermined number of revolutions of spin about a spin axis extending through said mechanism, said mechanism comprising: a centrifugally operable rotor mounted to pivot about a first axis displaced from said spin axis and having a center of mass displaced from said first axis whereby spinning of said mechanism about said spin axis urges said rotor from an unarmed angular position in which said center of mass is relatively nearer said spin axis toward an armed angular position in which said center of mass is relatively farther from said spin axis; camming teeth on said rotor; and balance means mounted to pivot about a second axis displaced from said first axis and from said spin axis and positioned to oscillate back and forth about said second axis in response to engagement by successive ones of said camming teeth as said rotor moves toward said armed position; the improvement wherein said balance means has a center of mass nearer said spin axis than is said second axis, whereby the oscillations of said balance means are opposed at least in part by centrifugal forces acting on said balance means in response to rotation of said mechanism about said spin axis.