Abstract:
A method for controlling a lifetime of a firearm including replacing a former portion of a firing mechanism of the firearm with a new portion, and constructing the new portion of the firing mechanism with a mechanical strength weaker than the former portion so that the new portion mechanically fails after significantly less rounds have been fired from the firearm than with the former portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 12/099,819, filed Apr. 9, 2008, which claims priority under 35 USC §119 to U.S. Provisional Patent Application 60/910,854, filed Apr. 10, 2007, which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to firearms, and particularly to a firearm that is limited in the number of shots that can be fired. 
       BACKGROUND OF THE INVENTION 
       [0003]    Firearms, such as handguns and rifles, are designed for years of reliable service for use by law enforcement personnel and law-abiding citizens. 
         [0004]    A disposable, single shot gun has also been proposed. A pistol, known as the WWII FP-45 Liberator Pistol, was originally developed in 1942 for the U.S. Army. It was a single-shot, smooth bore .45 caliber pistol. According to the Wikipedia article http://en.wikipedia.org/wiki/FP-45_Liberator, “An interesting fact about the Liberator is that the factories could produce one faster than the weapon could be loaded and fired. The factory turned out a pistol every six or seven seconds whilst loading took about 10 seconds. Another variant of this gun was a two shot version which never made general production. It had two chambers, where one would be fired and then the other slid into position to fire. This version is extremely rare”. 
         [0005]    It is important to note that although intended for shooting one round, the WWII FP-45 Liberator Pistol was not rendered incapable of shooting after firing one or more rounds. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention seeks to provide a limited use firearm, as is described in detail further hereinbelow, and seeks to limit the use of the firearm in manners different from the prior art. 
         [0007]    In the present invention, planned obsolescence is deliberately built into a portion of the firing mechanism (e.g., the sear or breech block) to render the firearm incapable of firing. This is contrary to prior art weapons manufacturers and consumers who want the firearm to last forever. 
         [0008]    There is thus provided in accordance with an embodiment of the present invention a method for controlling a lifetime of a firearm including replacing a former portion of a firing mechanism of the firearm with a new portion, and constructing the new portion of the firing mechanism with a mechanical strength weaker than the former portion so that the new portion mechanically fails after significantly less rounds have been fired from the firearm than with the former portion. 
         [0009]    For example, the new portion of the firing mechanism may be constructed with a yield strength weaker than that of the former portion. As another example, the new portion of the firing mechanism may be constructed with dimensions that obtain a smaller moment of inertia than that of the former portion. 
         [0010]    There is also provided in accordance with an embodiment of the present invention a method for controlling a lifetime of a firearm including placing an element in the firearm, wherein after a certain number of rounds has been fired from the firearm, the element moves to a position that prevents a firing mechanism of the firearm from firing a round. 
         [0011]    For example, after the certain number of rounds has been fired, the element moves to a position that prevents a round from being chambered for firing. As another example, the firearm is provided with a shot counter that causes the element to move to the position that prevents the firing mechanism of the firearm from firing a round. 
         [0012]    In accordance with an embodiment of the present invention a warning may be provided before the certain number of rounds has been fired that the firearm will soon be rendered unfit for firing. 
         [0013]    In accordance with an embodiment of the present invention a processor controls deployment of the element, the processor being programmable by a user to set the certain number of rounds to a user-selected number. 
         [0014]    In accordance with an embodiment of the present invention the shot counter is programmable by a user to set the certain number of rounds to a user-selected number. 
         [0015]    In accordance with an embodiment of the present invention the firearm is provided with a remote-controllable element that renders the firearm unfit for use after the certain number of rounds. 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0016]    The present invention provides a method for controlling the lifetime of the gun by limiting the number of rounds the firearm can fire. In accordance with an embodiment of the present invention, after a certain number of rounds have been fired, the firearm is rendered incapable of firing more rounds. The certain number of rounds may or may not be predefined. The firearm may be permanently or temporarily rendered incapable of firing more rounds. 
         [0017]    In one embodiment, after the certain number of rounds has been fired, a portion of a firing mechanism of the firearm may have a mechanical failure or stoppage and become unfit for use. For example, the sear spring, trigger bar spring, breech block, striker, striker spring, striker dampening spring, recoil spring and others, may become mechanically fatigued and break, making it impossible to fire the firearm. This may be accomplished by deliberately changing the material of this portion of the firing mechanism. For example, if the portion of the firing mechanism in the prior art is designed to withstand a tensile force of 100 kg for 1 million operative cycles and is made of steel with a tensile strength of 1700 MPa and yield strength of 1500 MPa (e.g., UNS G43400 steel), then in the present invention, the same part would be made of a much weaker material, such as but not limited to, an engineering plastic (e.g., polycarbonate, polybutylene terephthalate (PBT), and others), with 50-100 times weaker tensile and yield strengths, and fatigue strength 50-100 times weaker than the prior art material. Alternatively or additionally, in the present invention, the same part would be made with thinner dimensions so as to greatly reduce the moment of inertia and therefore greatly reduce the number of operative cycles. For example, if the prior art part was 5 mm thick, in the present invention it could be made 1 mm thick, thereby weakening the moment of inertia of the part in relation to a particular axis by 125 fold (the moment of inertia being a function of the thickness to the third power). 
         [0018]    Alternatively, an element disposed in the firearm may move to a position that prevents a firing mechanism of the firearm from firing a round or prevents a round from being chambered for firing. As another alternative, an element disposed in the firearm may move to a position that prevents a firing mechanism of the firearm from firing after a specific pre-programmed date. 
         [0019]    In accordance with an embodiment of the present invention the firearm may be provided with a shot counter and the shot counter may trigger an action to render the firearm unfit for use upon counting the certain number of rounds. 
         [0020]    For example, the shot counter can be used to provide the firearm with a limited and/or programmed life expectancy. As another example, the shot counter can limit the use of the firearm to a certain amount of rounds, and then can be released again for additional rounds, such as by an authorized person resetting or releasing the shot counter. 
         [0021]    The shot counter can limit the shots according to a certain date. In all these examples, the shot counter can cause limited use of the firearm as described above (e.g., a portion of a firing mechanism of the firearm having a mechanical failure or stoppage, the sear or breech block becoming mechanically fatigued, element disposed in the firearm moving to a position that prevents a firing mechanism of the firearm from firing a round, etc.) by being mechanically or electrically linked to an appropriate portion of the firearm (sear, breech block, firing mechanism, etc.). 
         [0022]    A warning may be provided before the certain number of rounds has been fired that the firearm will soon be rendered unfit for firing. 
         [0023]    A processor (controller) may be provided that controls deployment of the element that renders the firearm unfit for use (or the shot counter), the processor being programmable by a user to set the certain number of rounds to a user-selected number. 
         [0024]    The firearm may be provided with a remote-controllable element that renders the firearm unfit for use after the certain number of rounds. 
         [0025]    There is also provided in accordance with an embodiment of the present invention apparatus including a firearm including a firing mechanism and an element which is adapted to prevent the firing mechanism from firing a round after a certain number of rounds has been fired. 
         [0026]    Other possible applications of the invention include a person purchasing a firearm for a certain number of rounds and then returning the firearm to the manufacturer for service. 
         [0027]    Another possibility includes limiting a shooter to usage of the firearm until a certain age (e.g., 75), whereupon the firearm is rendered unfit for use until the person passes a sight/health examination, or simply blocking the gun after a specific date. 
         [0028]    It is appreciated that various features of the invention which are, for clarity, described in the contexts of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.