The safety of the soldiers in the field is high on the priorities of weapons design. Not only are soldiers constantly exposed to enemy fire and a hostile environment during battlefield engagement, they are also exposed to the firing hazards of their own weapons and launch equipment. Often times, the launch equipment and munitions may be worn out or become unsafe due to intense use, operator error, improper maintenance or poor weather conditions, resulting in an increase of potential hazards to the soldiers. It is therefore an important goal to minimize the potential hazards to soldiers operating weapons in the field despite such real world adverse conditions.
In one conventional design of an artillery gun, the recoil buffering mechanism for the artillery gun comprises a breech assembly and a barrel, wherein the barrel and breech do not provide any special safety design for the operator standing behind the breech to fire the artillery gun. This configuration leaves the operator fully exposed to the dangers of explosives and hot combustion gases leaking from the gun in case the breech accidentally opens during the gun firing.
More specifically, when the breech is in an open position, the munition is loaded axially into the firing chamber. To perform this operation, the operator positions himself or herself at a distance from the breech. Next, the breech is closed in preparation for firing. Since the firing event is accomplished almost instantaneously, the operator remains at the distal position, behind the breech, during the entire firing operation.
A significant pressure rise results from firing the munition. It is necessary for the breech to remain safely closed during the firing in order to impart the maximum forward momentum to the projectile, and to prevent any of the explosives and hot combustion gases from leaking past the breech to cause harm to the operator along the leakage path.
However, due to wear, debris or other unforeseen factors, the breech might not be fully closed prior to, or during the firing of the weapon, resulting in leakage of explosives and hot combustion gases from the barrel to a position distal to the breech where the operator is positioned. This exposure increases the hazard of the operator and could pose substantial danger to operator safety.
In one embodiment, of a safety and arming mechanism for a rifled gun, the mechanism is controlled by three projectile parameters. The first and second parameters are the axial and angular accelerations of the fired projectile, which move a setback ball to arm the mechanism. The third projectile parameter, i.e., angular velocity, is utilized to lock the setback ball in the armed position. As the projectile continues its flight, it only becomes armed when a spin actuated escapement mechanism is moved to a fully armed position. In addition, a command arm signal is required to release the arrangement such that the escapement mechanism is in a condition to complete its motion to the fully armed position.
Such weapon arming safety design is implemented in the munition only and not in the launch equipment. It does not explicitly address safety against explosive hazards or firing hazards at the point of firing in case a catastrophic failure occurs, as in the case of firing artillery rounds, and the breech suddenly becoming loosened from the closed position, leaking explosives and hot combustion gases behind the breech.
Another conventional safety-and-arming device is based on micro-electromechanical system (MEMS). Two independent mechanical locks are moved out of the way to allow the arming slider to remove a barrier in the explosive train to arm a fuze or close a switch for firing. The mechanical locks respond only to valid launch or deployment conditions. In addition, the mechanism does not explicitly address safety against explosive hazards at the point of firing in case a catastrophic failure occurs.
In yet another conventional device, a projectile is launched with on-board linear acceleration sensors to measure at least two accelerations, and the recorded time interval between the two accelerations would need to fall within a pre-determined range in order to arm the munition for detonation. This device assures the safety of arming the munition as long as the launched projectile achieves target values in flight parameters. When this goal is not achieved, the munition in flight would not be allowed to detonate. However, this device deals with the safety to arm the projectile after becoming airborne, and not with the safety of the weapon system during the firing process to protect the weapon operators.
In still another embodiment, a firearm safety locking mechanism prevents accidental or unauthorized use of the weapon. The safety locking mechanism is placed and operates in the firing chamber or in the barrel of the weapon. One of the goals of this mechanism is to prevent accidental use by an under-aged operator. However, such mechanism does not address the firing hazard reduction in case the firing chamber fails to hold the hot explosive gases in place inside the weapon.
Although these conventional technologies have proven to be useful, the issue of safety at the point of firing has not been addressed, and it would be desirable to present additional improvements to further reduce firing hazard. What is needed is an artillery gun equipped with a breech having a mechanism to safeguard against premature firing of munitions before the breech is fully closed. The safety mechanism should prevent explosives and hot combustion gases from the primer and the charge from quickly leaking from the firing chamber past the breech and subjecting to harm any personnel in the path of leakage. The need for such a safety mechanism has heretofore remained unsatisfied.