Abstract:
A safety mechanism for a firearm with a lock pivotally attached to the firearm and an insertable key, which is disposable in the lock. In an off-safe position, the key is disposed within the lock and the lock is held against the firearm when a user grasps a handle portion of the firearm. When the lock is no longer being held against the firearm, the lock pivots away from the firearm and the key is ejected from the lock, such that the lock is in an on-safe position. When the key is absent from within the lock, the lock cannot be pivoted toward the firearm. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application claims priority under 35 U.S.C. § 119 (e) to, and hereby incorporates by reference, U.S. Provisional Application Ser. No. 60/388,215, filed Jun. 13, 2002 and U.S. Provisional Application Ser. No. 60/478,071, filed Jun. 12, 2003. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to safety mechanisms and, in particular, this invention relates to safety mechanisms for firearms. 
   2. Background 
   Virtually every firearm possesses at least one safety mechanism. These safety mechanisms prevent the firearm from being operated when the safety mechanism is in what may be termed an “on-safe” position. The safety mechanism may block a component, such as a trigger, trigger bar, hammer, or firing pin, from being displaced. Thus, if pressure is inadvertently applied to the trigger, one of the foregoing components cannot be displaced and the firearms is not unintentionally fired. Other safety mechanisms have been proposed to augment or replace the foregoing mechanical mechanisms. Some of these other safety mechanisms examine the user&#39;s fingerprints to match a predetermined fingerprint pattern before the firearm can be utilized. Another safety mechanism includes a transponder and requires a specified electromagnetic source, e.g., worn as a wrist band, proximate the transponder to activate the safety mechanism before the firearm can be fired. Other technologies proposed to augment traditional mechanical safety mechanisms utilize mechanical combination locks, electromechanical locks, electromagnetic locks and magnetic locks. While the foregoing technologies potentially enhance the safety of firearms, they lack the dependability inherent in safety mechanisms employing only mechanical components. For example, the foregoing additional mechanisms usually require electricity for operation. The required electricity will almost certainly be obtained from batteries, the batteries, in turn, exhaustible. Hence, firearm safeties utilizing electrical components may be inoperable if batteries are exhausted. 
   Another concern regarding currently available safety mechanisms for firearms is that none of the known mechanical safety mechanisms automatically disarms a firearm when not being gripped by a user, such that the firearm cannot be re-grasped and fired. Instead, a user must manually adjust the safety mechanism of some mechanical mechanisms between an on-safe or off-safe position. In other mechanical safety mechanisms, a safety is present at locations where the firearm is normally grasped, e.g., at the grip of a semi-automatic pistol. Typically, grasping the firearm pivots the safety into an off-safe position, thereby allowing the firearm to be fired. However, an unintended user can grasp and use a firearm previously in an on-safe position, because the unintended user is not required to bring the firearm to an off-safe position by performing any subsequent mechanical step. 
   There is then a need for a firearm safety mechanism which is self-disarming. There is a particular need for a firearm safety mechanism which is self-disarming and is completely composed of mechanical components and in which a subsequent mechanical step must be performed before the safety mechanism can be adjusted to an off-safe position. 
   SUMMARY OF THE INVENTION 
   This invention substantially meets the aforementioned needs of the industry by providing an entirely mechanical safety mechanism for firearms, which prevents the firearm from being fired when the firearm is not being grasped and which requires a further mechanical step before the safety mechanism can be adjusted to an off-safe position. 
   It is therefore an object of this invention, to provide a safety mechanism for a firearm including a lock, an ejection mechanism, and a key. The lock cooperates with a structure firing the firearm. The key may be insertable into the lock such that the key may be ejected from the lock by the ejection mechanism unless secured therein, e.g., against a surface of the firearm. 
   A further object is to provide a process of installing or retrofitting a safety assembly in a firearm. The process may include 1) pivotably affixing a lock to the firearm; 2) biasing the lock away from a firearm; and 3) providing a key, the key insertable into the lock. 
   One feature of particular embodiments of the invention is that the present safety mechanism is comprised entirely of mechanical components. 
   A corresponding advantage of the foregoing feature is that the present safety mechanism does not rely on electrical or electromagnetic energy, which must be supplied by exhaustible batteries. 
   Another feature of the present safety mechanism is that a component pivots away from the firearm when the firearm is not being grasped by a user. 
   A corresponding advantage of the foregoing feature is that the firearm is automatically disarmed when not being grasped. 
   Yet another feature of the present safety mechanism is that the pivotable component ejects a key when pivoting away from the firearm and that the pivotable component cannot be pivoted toward the firearm unless the key is disposed within the pivotable component. 
   One corresponding advantage of the foregoing feature is that the present safety mechanism cannot be activated to an off-safe position by persons not possessing the key. 
   Yet still another feature of one embodiment of the present safety mechanism is that the pivotable component can be retained in a position proximate the firearm when a separate safety is in an on-safe position, whether or not the firearm is being grasped. 
   One corresponding advantage of the foregoing feature is that the firearm may be placed in a holster without being deactivated by the present safety mechanism. 
   Another corresponding advantage of the foregoing feature is that the firearm may be released by a user without deactivating the firearm, when the present safety assembly is in an off-safe position. 
   These and other objects, features, and advantages of this invention will become apparent from the description which follows, when considered in view of the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a semi-automatic pistol of the prior art; 
       FIG. 2  is a partial cross sectional view of another semi-automatic pistol of the prior art; 
       FIG. 3  is a partial side view of a pistol retrofitted or installed with one embodiment of the present safety assembly in an on-safe position; 
       FIG. 4  is a partial side view of the pistol and safety assembly embodiment of  FIG. 3  in an off-safe position; 
       FIG. 5  is a partial side view of a pistol retrofitted or installed with a second embodiment of the present safety assembly in an on-safe position; 
       FIG. 6  is a partial side view of the pistol and safety assembly embodiment of  FIG. 5  in an off-safe position; 
       FIG. 7  is a cross sectional view of one embodiment of the present lock and key; 
       FIG. 8  is a cross sectional view of the lock and key of  FIG. 6 , the key inserted enabling the lock to pivot; 
       FIG. 9  is a cross sectional view of the lock and key of  FIG. 7 , in which the key is inserted into the lock; and 
       FIG. 10  is a cross sectional view of the lock and key of  FIG. 7 , in which the key is inserted and the lock pivoted in an off-safe position. 
   

   It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit the scope thereof. 
   DETAILED DESCRIPTION 
   Any references to such relative terms as upper, or the like, are intended for convenience of description and are not intended to limit the present invention or its components to any one positional or spatial orientation. 
   Each of the additional features and methods disclosed herein may be utilized separately or in conjunction with other features and methods to provide improved safety mechanisms and methods for making and using the same. Representative examples of the teachings of the present invention, which examples utilize many of these additional features and methods in conjunction, will now be described in detail with reference to the drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, combinations of features and methods disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative and preferred embodiments of the invention. 
   The present invention includes a safety assembly for a firearm such as a semi-automatic pistol, a revolver, a bolt action rifle, a semi-automatic rifle, automatic firearms employing fire control mechanisms known to persons of skill in the art, and to shotguns with any of the foregoing firing mechanisms. 
   In its broadest sense, the present safety assembly provides a component, which may be ejected from the firearm, thereby placing the firearm in an on-safe position. The ejectable component may be held in place by such means as a user gripping a handle of a firearm utilizing the present safety assembly. 
   In another sense, the present safety assembly employs a pivotable component which receives the ejectable component. The pivotable component is biased away from the firearm. When biased away from the firearm, the pivotable component is in a on-safe position and the firearm cannot be operated. To operate a firearm utilizing the present pivotable component, the pivotable component must be retained proximate the firearm in an off-safe position and the ejectable component must be disposed within the pivotable component. If the pivotable component is allowed to pivot away from the firearm, the firearm cannot be operated because the pivotable component and the firearm are in an on-safe position. Moreover, the ejectable component may be simultaneously ejected from the pivotable component as the pivotable component pivots away from the firearm. In the absence of the ejectable component, the pivotable component cannot be pivoted proximate the firearm to an off-safe position. 
     FIGS. 1 and 2  depict a semi-automatic pistol known to persons of ordinary skill in the art and to which the present invention may be installed as original equipment or retrofitted. Obviously, a person of ordinary skill in the art would also be able to retrofit other firearms, e.g., revolvers, rifles, shotguns, to operably accommodate the present safety system without undue experimentation. In  FIGS. 1 and 2 , the semi-automatic pistol is shown generally at  50  and includes a frame  52  with a grip portion  54 , and a breech-slide  56  with a breech block  57  movably connected to the frame to enable foreword and rearward movement with respect to the frame  52  and the slide  56 . A barrel  58  is mounted atop the frame  52 . The barrel  58  includes a chamber  60  dimensioned to accommodate a cartridge  62 . A magazine  64  holds numerous cartridges  62 . The magazine  64  feeds the cartridges  62  by urging the cartridges toward the breech block  57  via a follower  66  and spring  68 . The cartridges  62  are fed into the chamber  60  responsive to the movement of the slide  56 . The magazine  64  is removably inserted into a magazine receiver  70  defined within the grip  54  of the pistol  50 . The pistol  50  typically has a hammer  72  for striking a firing pin  74 , which, in turn, strikes a primer (not shown) of a cartridge  62 , when the cartridge  62  disposed within the chamber  60 . A main spring  76  biases the hammer  72  toward the firing pin  74 . A trigger  78  is connected to a trigger bar  80  that cooperates with a mechanical linkage (not shown) to release the cocked hammer to strike the firing pin, which consequently strikes the primer of the cartridge  62 . The trigger  78  is positioned within a trigger guard  82 . An extractor  84  and an injector system (not shown) eject a spent shell (or casing) from the open breech and a recoil spring  86  returns the slide  56  to a foreword and breech-closed position after the pistol  50  has been fired. Safety mechanisms usually present include a grip safety  88  and a thumb lever safety  90 . The grip safety  88  normally locks the trigger  78 , or otherwise prevents discharge of the cartridge, until the grip  54  of the pistol is grasped by a user&#39;s hand. The thumb lever safety  90  locks the trigger  78  (or other firing components) when pivoted into the on-safe position. 
     FIGS. 3–4  depict a first embodiment of a safety assembly of the present invention generally at  100  and which includes a pivotable component such as a lock  102  pivotably mounted to the pistol  50  at a pivot point  104  by a connector  106 , such as a pin commonly known to the art and an ejectable component, such as a key  108  accommodated in the lock  102  and more fully explained infra. In the embodiment depicted, the lock  102  has a biasing member, such as a lock spring  114 , and an optional lock mechanism, one embodiment of the present lock mechanism is more fully explained infra. 
   A slide lock lug  118  and a firing pin linkage lug  120  are formed proximate an upper end  116  of the lock  102 . However, a person of ordinary skill in the art will readily recognize that the present safety assembly can be readily modified without undue experimentation such that that a tensioning member is operably present as a component of the key  108 , rather than as a component of the lock  102 . Another tensioning member, such as a spring  122 , is operably attached between the lock  102  and the pistol grip portion  54  to urge the lower portion of the lock  102  to pivot away from the grip portion  54 . 
     FIG. 3  depicts the safety assembly  100  engaged in an on-safe position wherein the lock  102  is pivoted away from the pistol grip portion  54  by the spring  122 . In the on-safe position, the slide lock lug  118  is disposed in a notch  124  of the slide  56  and the firing pin linkage lug  120  is displaced downwardly, thereby allowing a firing pin safety pushrod  126  to displace a firing pin safety  128  such that the firing pin safety  128  fixes (locks) the firing pin  74 . The locked firing pin  74  cannot be displaced forwardly; hence, cannot impact the cartridge primer to initiate cartridge propellant ignition. As more fully explained infra, the lock  102  cannot be pivoted toward the pistol grip  54  until the key  108  is suitably disposed in the lock  102 . In  FIG. 3 , the key  108  has been ejected from the lock  102  in the direction of an arrow  130  by the spring  114 . The spring  114  ejects the key  108  when being allowed to return to an unbiased position from a biased position, the unbiased position being depicted in  FIG. 3 . In the on-safe position depicted in  FIG. 3 , the pushrod  126  is released, allowing the firing pin safety  128  to lock and secure the firing pin  74 . The on-safe position depicted in  FIG. 3  also depicts the slide lock lug  118  firmly engaged in the slide notch  124 , preventing displacement of the slide  56  as well. 
   While the biasing members  114  and  122  are depicted as springs, a person of ordinary skill in the art will readily comprehend that the biasing members can also utilize embodiments employing other means, such as pressurized gas or magnetism to accomplish the stated functions without undue experimentation. In other embodiments, a person of ordinary skill in the art will recognize that electromagnetic and electric components may be employed as well in lieu of the springs  114  and  122 . 
     FIG. 4  depicts the present safety assembly  100  in an off-safe position. In the off-safe position, the key  108  is disposed within the lock  102 , thereby biasing the spring  114  and allowing the lock  102  to be pivoted toward the grip  54 , thereby also biasing the spring  122 . In the off-safe position, the key  108  is held in place against an upper edge  132  of the grip  54 . However, the biased spring  122  will displace (urge) the lock  102  to the on-safe position unless held in place, e.g., by a user&#39;s hand gripping the portion  54 . If the user&#39;s hand releases the grip  54 , the spring  122  will pivot the lock  102  to the on-safe position and the spring  114  will eject the key  108 . With the key  108  ejected, the lock  102  cannot be returned to the off-safe position unless the key  108  is reinserted. In the off-safe position, the slide lock lug  118  is displaced out of the slide notch  124  and the firing pin linkage lug  120  displaces the firing pin safety pushrod  126 , thereby displacing the firing pin safety  128  to an unlocked position. When the firing pin safety  128  is in an unlocked position, the firing pin  74  is free to be displaced, e.g., by a hammer, and the pistol  50  can be operated. 
   A second embodiment of the present safety assembly is depicted in  FIGS. 5–6 , generally at  148 . Features unique to the safety assembly  148  include a lock  150  pivotally mounted to the pistol  50  at a pivot point  152  by a connector known to the art, such as a pin  154 . The lock  150  has an upper end  160 , wherein the lugs  118  and  120  of the lock  102  are not present. The lock  150  operably interacts with an external safety, such as the thumb lever safety  90 , which may be modified in some embodiments. In the embodiment depicted, the thumb lever safety  90  includes lugs  164  and  166  and is pivotally mounted at  168 . In some embodiments, the thumb lever safety  90  has been modified to include the internal lug  166 . The lug  164  disposes in the slide notch  124 , but is displaced out of the slide notch  124  when the thumb lever safety  90  is pivoted to the off-safety position. The lug  166  extends downwardly from the main body of the thumb lever safety  90  and can be operably contacted by the lock  150  as more fully explained infra. 
   In  FIG. 5 , the lock  150  has been pivoted away from the grip portion  54  when the spring  122  has been allowed to assume an unbiased disposition and the key  108  has been ejected from the lock  150  by the spring  114  in the direction of the arrow  130 . The lock  150  cannot be pivoted toward the grip portion  54  until the key  108  is reinserted therein. In this position, the trigger pushrod  80  is locked to place the pistol  50  in an on-safe position, in which the trigger cannot be displaced to fire the pistol. 
   However, in  FIG. 6 , the internal lug  166  of the thumb lever safety  90  retains the lock  150  in the off-safe position when the thumb lever safety  90  is in an on-safety position. In  FIG. 6 , the safety assembly  148  is in an off-safe position, in which the lock  150  has been pivoted toward the grip  54 , thereby compressing the spring  122 . The off-safe position depicted in  FIG. 6  is enabled because the thumb lever safety  90  is pivoted to an on-safety position, in which the lug  164  is disposed in the slide notch  124  and in which the trigger pushrod  80  is in an unlocked position. Because the thumb lever safety is in an on-safe position, the pistol  50  cannot be operated, whether the present safety assembly is in an on-safe or off-safe position. Thus, the lug  166  retains the lock  150  in an off-safe position, but a position in which the pistol  50  cannot be fired nonetheless. The pistol  50  can be said to be in a standby position, because the lug  164  of the thumb lever safety  90  is disposed in the slide notch  124 . Moreover, the key  108  is retained in the lock  150  against the upper edge  132 . In the configuration depicted by  FIG. 6 , the pistol  50  can be placed in a holster or released without the present safety assembly automatically assuming an on-safe position. To operate the pistol  50 , the user then grips the pistol grip  54  and places the safety  90  in an off-safe position. Additionally, when the present device is in the position illustrated by  FIG. 6 , the slide  56  is locked by the thumb lever safety  90  and cannot be displaced until the lug  164  is moved out of the notch  124 . Because the slide  56  is locked, the pistol  50  cannot be field stripped, until the lug  164  is removed from the notch  124 . 
   Referring to  FIGS. 7–10 , an exemplary embodiment of the present lock and key mechanism is depicted and includes a lock  200  and a key  202 . The lock  200  is one illustrative mechanism of the locks  202  and  150 . The key  202  is likewise an illustrative mechanism of the present key  108 . 
   The lock  202  includes an inner core  208  and an outer housing  210 . The inner core  208  and the outer housing  210  cooperate to enclose at least one, e.g., six, inner and outer pins  212  and  214 , respectively, and an identical number of corresponding pin springs  216 . The inner and outer pins  212  and  214  and the pin springs are operably disposed in slots defined by a cooperation of the inner core  208  and the outer core  210 . An interior of the inner core  208  defines a shear line  218  and a slot (cavity) accommodating the key  202 . The key  202 , in turn, has a plurality of cuts  224  defining a plurality of nodes  225 , the number of nodes  225  equal to the number of inner and outer pin  212  and  214  and pin spring  216  combinations. 
   The lock  200  and the key  202  represent an embodiment of a step lock and step key, wherein the resistance or drag is created as the key  202  is displaced over the inner pins  212  is greatly minimized, or essentially eliminated. The lock  200  and key  202  eliminate a large portion of the friction created as the key is displaced past, thereby contacting, the inner pins  212 , because the inner pins  212  are not being raised and lowered, or otherwise urged against the springs  216 , as would be the case with most of the other locks known to the art. In further contrast to other locks known to the art, the key cuts  224 , hence nodes  225 , engage and disengage simultaneously, thereby enabling injection and ejection of the key  202  to occur more quickly and require less energy. 
   In contrast to keys and locks known to the art and in which all cuts, hence nodes, are fashioned at the same, or closely adjacent, planes, the cuts and nodes of the key  202  have steps beginning with the first node from the key apex. Each subsequent key cut and node defines a wider corresponding key dimension and a correspondingly narrower inner pin length, the corresponding inner pin length shortened by the same dimension. For example, if a key of the present embodiment has nine cut depths of 0.002 inch per cut, a total of 0.018 inch per step is utilized and the next, or succeeding, step present in the key would be 0.018 inch wider and the corresponding inner pin would have a dimensional length shorter than the previous adjacent pin. In the embodiment depicted, when the nodes in the keys aligned the juncture of the inner and outer pins at the shear line, the lock is unlocked, and can rotate on the pivoted  104 , the inner core pivoting against a substantially flat surface of the outer housing. 
   While the lock  200  and key  202  are depicted as a working embodiment, a person of ordinary skill in the art will readily recognize that other lock and key embodiments would be suitable as well, e.g., if the spring  114  possessed sufficient strength to eject other embodiments of the present key. 
   The key-lock combinations can be individually configured for individual users or for an entire group of persons, e.g., a police or military unit. 
   Although the present invention has been described with reference to depicted embodiments, persons of ordinary skill in the art will readily recognize that various modifications and changes may be made without departing from the spirit and scope of the invention. For example, any number and types of safety mechanisms can be activated or deactivated by pivoting the present lock. Moreover, any number and types of safety mechanisms can be activated or deactivated by the presence or absence of the present key within the lock of this invention.