Mechanical thermal battery initiator

Abstract

A mechanical thermal battery initiator for a round where the initiator has a firing pin positioned to strike a primer of a thermal battery upon activation. After installation of the initiator/battery assembly in a round, the end user need not perform any further tasks until firing the munition. At launch, any safety device installed to prevent unintended activation is removed or switched to an active state. When launched, the initiator is subjected to centripetal force and acceleration causing a setback ring to release ball bearings and a spring force from a firing pin spring to push a firing pin into contact with a primer to initiate power on the round.

What is claimed: 
     
         1 . A mechanical thermal battery initiator for a round, comprising:
 a body, comprising:
 an inner central bore configured to slidably retain a firing pin and a firing pin spring; 
 a concentric outer bore spaced away from the central bore being configured to retain a setback ring and at least two ball bearings; and 
 at least two spring-loaded centripetal pins each located in a cross bore and configured to engage with the setback ring at rest and disengage from the setback ring when under centripetal force; 
 wherein once the initiator is exposed to centripetal force and acceleration due to a launch of the round the setback ring releases the at least two ball bearings and a spring force from the firing pin spring pushes the firing pin into contact with a primer on the thermal battery to initiate power on the round. 
   
     
     
         2 . The initiator according to  claim 1 , further comprising a mechanical interlock or Safety Switch configured to prevent inadvertent activation during shipping or handling. 
     
     
         3 . The initiator according to  claim 1 , further comprising a housing for containing the mechanical thermal battery initiator having an opening that exposes the firing pin. 
     
     
         4 . The initiator according to  claim 1 , wherein a shelf life of the initiator is longer than a shelf life of the thermal battery. 
     
     
         5 . The initiator according to  claim 1 , wherein a primer impact force for the thermal battery is less than or equal to 50 lbs. 
     
     
         6 . The initiator according to  claim 1 , wherein a minimum of 6 Hz rotation is needed to release the setback ring on the initiator. 
     
     
         7 . The initiator according to  claim 1 , wherein the initiator comprises four centripetal pins, evenly spaced about a central axis, thus preventing a single shock event from freeing all of the centripetal pins from the setback ring. 
     
     
         8 . The initiator according to  claim 1 , wherein the centripetal pins are pointed and are configured to mate with a V-notch in the setback ring to allow the pins to consistently reseat on the setback ring. 
     
     
         9 . The initiator according to  claim 1 , wherein a spring force for the centripetal locking pins is less than a pound. 
     
     
         10 . The initiator according to  claim 1 , wherein an activation time of the initiator is less than 200 ms of flight time. 
     
     
         11 . A method for mechanically initiating a thermal battery on a round, comprising:
 providing a mechanical initiator, comprising:
 an inner central bore configured to slidably retain a firing pin and a firing pin spring; 
 a concentric outer bore spaced away from the central bore being configured to retain a setback ring and at least two ball bearings; and 
 at least two spring-loaded centripetal pins each located in a cross bore and configured to engage with the setback ring at rest and disengage from the setback ring when under centripetal force; 
   exposing the initiator to centripetal force and acceleration due to a launch of the round;   disengaging the setback ring and releasing the at least two ball bearings;   pushing the firing pin into contact with a primer on the thermal battery via a spring force from the firing pin spring; and   initiating power on the round.   
     
     
         12 . The method according to  claim 11 , further comprising providing a mechanical interlock or Safety Switch configured to prevent inadvertent activation during shipping or handling. 
     
     
         13 . The method according to  claim 11 , further comprising providing a housing for containing the mechanical thermal battery initiator having an opening that exposes the firing pin. 
     
     
         14 . The method according to  claim 11 , wherein a shelf life of the initiator is longer than a shelf life of the thermal battery. 
     
     
         15 . The method according to  claim 11 , wherein a primer impact force for the thermal battery is less than or equal to 50 lbs. 
     
     
         16 . The method according to  claim 11 , wherein a minimum of 6 Hz rotation is needed to release the setback ring on the initiator. 
     
     
         17 . The method according to  claim 11 , wherein the initiator comprises four centripetal pins, evenly spaced about a central axis, thus preventing a single shock event from freeing all of the centripetal pins from the setback ring. 
     
     
         18 . The method according to  claim 11 , wherein the centripetal pins are pointed and are configured to mate with a V-notch in the setback ring to allow the pins to consistently reseat on the setback ring. 
     
     
         19 . The method according to  claim 11 , wherein a spring force for the centripetal locking pins is less than a pound. 
     
     
         20 . A munition, comprising:
 a guidance unit;   a controller;   at least one sensor coupled to the guidance unit for directing the munition to a target area;   an explosive charge;   a fuse assembly coupled to the explosive charge;   a battery;   a mechanical battery initiator, comprising:
 an inner central bore configured to slidably retain a firing pin and a firing pin spring; 
 a concentric outer bore spaced away from the central bore being configured to retain a setback ring and at least two ball bearings; and 
 at least two spring-loaded centripetal pins each located in a cross bore and configured to engage with the setback ring at rest and disengage from the setback ring when under centripetal force; 
 wherein once the initiator is exposed to centripetal force and acceleration due to a launch of the munition the setback ring releases the at least two ball bearings and a spring force from the firing pin spring pushes the firing pin into contact with a primer on the battery to initiate power to the munition.