Not Applicable.
Not Applicable.
The present invention relates to firearm security in general and to firearms with authorization systems in particular.
There have been numerous improvements to firearm security over the years. However, there is an inherent paradox in firearm security. On one hand, a secure weapon may require several steps to be taken before it can be fired. For example, it may have to be removed from a locked cabinet. Ammunition may be stored separately. A trigger lock may need to be unlocked. Safeties may have to be moved to the xe2x80x9coffxe2x80x9d position. On the other hand, the user; who may be a law enforcement officer, may need to fire it quickly in emergencies to save lives or to save his or her own life. Inevitably, compromises are made in the design and storage of firearms between security and ready usability.
Historically, firearm safeties were of the type that, when the user wanted to fire the weapon, he or she moved a safety lever or catch from the xe2x80x9conxe2x80x9d position to the xe2x80x9coffxe2x80x9d position. Other safeties have been developed to complement this basic approach, all emphasizing that the user must intend to discharge the weapon in order for the weapon to be in a condition for it to be fired, or to be xe2x80x9cenabled.xe2x80x9d None of these systems questions the authority of the user who intends to fire the firearm.
More recently, firearms have been designed with authorization systems. These systems attempt to verify that the user is someone who is permitted to fire the firearm. An unauthorized user cannot fire the firearm equipped with an authorization system. Typically, these systems rely on some means of identification: the user enters a code on a keypad on the firearm or has a key that unlocks the firearm, or the firearm has the capability to read a particular individual""s fingerprint. Another type of authorization system relies on a xe2x80x9cpersonal devicexe2x80x9d worn by the authorized user that communicates using radio-frequency transmitters and receivers with electronic circuits carried in the firearm. Indeed, many improvements and variations have been made in existing authorization systems.
The nature of the use of the firearm must be considered in the design of an authorization system. For example, a firearm designed for shooting for sport can be designed with greater limitations on when it can be enabled. The design of authorization systems for law enforcement firearms are more challenging. Law enforcement officers must be prepared to fire their firearms on short notice. However, a law enforcement officer must sometimes grapple with a suspected criminal, risking the possibility that the suspected criminal could turn the officer""s firearm on the officer. Thus, in an instant, an ideally designed authorization system should give the firearm the capability to switch repeatedly and automatically between being enabled and being disabled as the struggle for control of the firearm continues.
Other design considerations must be taken into account as well when designing an authorization system for a law enforcement firearm. Authorization systems must not be easily defeated by those criminals who understand how these systems work. Authorization systems that rely on battery power must have a ready-to-fire condition even if the battery is dead. Accordingly, there remains a need for an authorization system that operates reliably, that does not drain its batteries quickly, and that is particularly suited for law enforcement use.
According to its major aspects and briefly recited, the present invention is an authorization system for a firearm designed especially for law enforcement use. The system includes a detector that can sense an authorization signal from the user and a firearm that responds appropriately to the authorization signal or to an absence of one.
The firearm queries the user for the authorization signal shortly after the firearm has been grasped and removed from the holster. If an authorization signal is not obtained, pulling the trigger will not cause the firearm to discharge. Specifically, a failure to authorize causes a brake solenoid to be held in the safe xe2x80x9cno firexe2x80x9d position in which the solenoid cams the trigger bar away from the sear. On the other hand, if authorization is obtained, the solenoid does not significantly affect the normal, rearward movement of the trigger bar.
A key feature of the present invention is the use of a particular type of solenoid placed in direct engagement with the top surface of the trigger bar. The solenoid has a rotatable armature assembly that can be locked in place or allowed to rotate based on whether or not the solenoid has received a small electrical current or not. The small electrical current to the coil of the solenoid stator assembly causes the plate to lock in place. The armature assembly carries a camming pin that will directly engage the top surface of the trigger bar. When locked, the pin cams the trigger bar out of engagement with the sear; when unlocked, the bar rotates the pin out of the way on its rearward travel to engage the sear as usual. This arrangement simplifies alignment of components, minimizes battery drain, increases reliability and allows the system to be in xe2x80x9cready to firexe2x80x9d condition at all times.
The use of a holster switch in combination with a grip switch to initiate authorization is another important feature of the present invention. The holster switch activates the battery and the grip switch activates the authorization system. Thus, the authorization system does not require touching or pulling the trigger itself to operate, merely the gripping of the unholstered firearm.
The logic circuitry of the present invention is another of its important features. The logic is based on a fire-enabled mode in the event of failure, rather than a fire-disabled mode, although the system can be easily modified to perform in a fire-disabled mode. Furthermore, a short delay is built into the authorization logic to permit the user to fire it, regardless of authorization, when the gun is first pulled from the holster. This allows a xe2x80x9cquick-drawxe2x80x9d firing, regardless of authorization, based on the presumption that the one pulling it from its holster is the authorized user and the need to fire the gun is immediate. However, the delay is short and in a fraction of a second after the delay, authorization will be confirmed.
The combination of circuit logic and the type of solenoid is another important feature of the present invention. In addition to having an authorization logic oriented to best suit the needs of law enforcement personnel, the logic also minimizes battery consumption. Although these sometimes competing goals may seem to be natural assumptions to make, how they are realized in practice is not intuitive but instead requires careful planning and compromise. For example, the power-consuming authorization process is only done when the gun is out of the holster and in someone""s grasp. Once done, reauthorization is not performed unless the gun is released for more than a pre-selected, short interval. There is also a xe2x80x9csleep modexe2x80x9d when the gun is out of the holster but not within the user""s grasp. In this mode it draws very little power. In the holster it draws none. Only when the person grasping the gun is not authorized, which is likely a very, very small percentage of the time, does the system require power for the solenoid.