Abstract:
A lockable firearm safety is incorporated into the bolt mechanism of a safety bolt to selectively block the forward motion of the hammer by either of two means: (a) preventing the trigger from moving rearward which movement would release the hammer permitting it to move forward and strike the firing pin; (b) by directly blocking the hammer from moving forward to strike the firing pin. When the safety bolt is placed in the safety position, the bolt may be locked in the safety position by means of a key. The firearm cannot be discharged until the safety bolt is unlocked and is moved to the fire position. The key is retained by the bolt unless the safety bolt is in the safety locked position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. application Ser. No. 09/067,487 filed Apr. 27, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to safety devices employed in firearms to prevent accidental or unauthorized discharge of the firearm. More particularly, this invention relates to safety devices which are lockable to prevent discharge of the firearm. 
     Safeties for firearms are commonplace, and numerous safety configurations have been advanced. One general type of safety mechanism involves the use of a manually displaceable cross bolt which is oriented generally transversely to the firearm barrel. The safety is operated by manually displacing the bolt between two axial positions which are retained by a spring biased detent or other means. 
     One such type of safety involves a hammer block which is axially displaceable between a fire and a safety position. The cross bolt is configured to selectively interfere with the hammer and/or a component in the trigger/hammer assembly to prevent the hammer from moving forward sufficiently to fire the firearm. In the safety position, the bolt blocks the hammer from engaging the firing pin or discharging the firearm. When the bolt is moved to the fire position, the hammer is free to move forward to strike the firing pin and discharge the firearm. 
     A second type of safety is a trigger block which may also be positioned to engage the trigger or a portion or extension of the trigger to prevent the trigger from being pulled or limit the displacement of the trigger when the bolt is in the safety position. In the safety position, the trigger cannot be activated to discharge the firearm. In the fire position, the trigger can be pulled to discharge the firearm. 
     The use of locks and locking mechanisms, including electronic devices, to further secure a firearm is also commonplace, and a wide variety of devices and techniques have been advanced. The vast majority of conventional firearm locks and locking mechanisms operate independently of the firearm safety. 
     SUMMARY OF THE INVENTION 
     Briefly stated, the invention in a preferred form is a lockable firearm safety which incorporates a locking mechanism into a cross bolt employed in a safety mechanism. The bolt is mounted in a bore disposed generally transversely of the barrel. The bolt is axially displaceable between the safety and the fire position. The bolt defines a lock recess and has a keyway axially extending through an end of the bolt. The bolt has axially spaced first and second surfaces which are respectively configured to prevent the discharge of the firearm in the safety position while allowing the firearm to discharge in the fire position. A detent assembly, which comprises a detent projectable into the lock recess of the bolt, locks the bolt in the safety position to prevent the bolt from being displaced to the fire position. 
     The bolt is rotatable by means of a key to an angular position which is generally diametrically opposite that of the normal safety position. The key has a blade insertable into the slot to cam the detent out of the lock recess to thereby allow the bolt to be angularly rotated and to permit axial displacement of the bolt from the safety to the fire position. The bolt also may be configured with first and second axially spaced recesses to retain the bolt in a semi-stable relationship in the safety and fire positions. 
     In one disclosed embodiment, the bolt is engageable with the trigger in the safety position to block the trigger from discharging the firearm. In a second disclosed embodiment, a hammer assembly is operatively connected to the trigger assembly. The bolt is engageable with the hammer assembly to block the hammer from discharging the firearm when the bolt is in the safety position. The detent assembly preferably comprises a detent pin and a spring which biases the pin toward the bolt. An outer surface of the bolt may be fixed with an indicator to indicate when the bolt is positioned in the locked angular position. 
     In another disclosed embodiment, the safety mechanism is secured in a locked position by means of a lock cylinder. A tailpiece extends from the lock cylinder plug. A lug extends from the tailpiece and is retainable in a slot upon angular rotation of the plug. The tailpiece includes a slot which receives an extension of the trigger when the safety is in the fire position and is also configured to engage the extension and obstruct rearward movement of the trigger when the safety is in the safety position. The lock cylinder may take the form of a key-retaining cylinder so that the key can only be removed when the locked safety position is achieved. 
     A sleeve-like liner may be interposed between the transverse bore and the bolt. The liner has a slot configuration which functions as a track for a lug which projects from the key blade. The track is configured so that the lug engages a shoulder of the track to prevent withdrawal of the key from the key slot unless the bolt is in the locked safety position. In addition, the key may be hinged so that it does not interfere with operation of the firearm. 
     An object of the invention is to provide a new and improved lockable safety for a firearm. 
     Another object of the invention is to provide a new and improved lockable firearm safety which is reliable and provides a high degree of security for a firearm. 
     A further object of the invention is to provide a new and improved lockable firearm safety having an efficient and low cost construction and which can be readily incorporated into a firearm without substantial modification thereof. 
     A yet further object of the invention is to provide a new and improved locking device firearm which is operatively coupled in a user friendly application in conjunction with a proven safety for a firearm. 
     Other objects and advantages of the invention will become apparent from the specification and the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a trigger guard assembly incorporating a lockable firearm safety in accordance with the present invention; 
     FIG. 2 is an enlarged fragmentary sectional view of the trigger guard assembly of FIG. 1; 
     FIG. 3 is a fragmentary view of components of the lockable firearm safety of FIG. 2 viewed generally in a direction of the lines  3 — 3  thereof; 
     FIG. 4 is a bottom plan view of the firearm safety components of FIG. 3; 
     FIG. 5 is a side elevational view of the component of FIG. 4, partly broken away to show section and partly in phantom, and rotated 90° clockwise from the right portion thereof; 
     FIG. 6 is a fragmentary end sectional view, partly broken away, of the component of FIG. 5; 
     FIG. 7A is a left end view and a corresponding schematic view of the firearm components of FIG. 3 illustrating a fire position thereof; 
     FIG. 7B is a left end view and a corresponding schematic view of the firearm safety components of FIG. 3 illustrating a safety position thereof in the unlocked position; 
     FIG. 7C is a left end view and a corresponding schematic view of the firearm safety components of FIG. 3 illustrating a safety position thereof in the locked position; 
     FIG. 7D is a left end view and a corresponding schematic view of the firearm safety components of FIG. 3 illustrating a safety position thereof in the unlocked position; 
     FIG. 7E is a left end view and a corresponding schematic view of the firearm components of FIG. 3 illustrating a fire position thereof; 
     FIG. 8 is a side view, partly broken away and partly in section, illustrating an alternate embodiment of a component for firearm safety in accordance with the invention; 
     FIG. 9 is a left end view, partly broken away to show section, of the component of FIG. 8; 
     FIG. 10 is a bottom plan view of the component of FIG. 8; 
     FIG. 11 is a perspective view of a representative key employed for the lockable firearm safety of FIG. 1; 
     FIG. 12 is a fragmentary perspective view, partly in phantom and partly broken away, of a firearm incorporating a second embodiment of a lockable firearm safety and a corresponding key in accordance with the invention; 
     FIG. 13 is a fragmentary perspective view of trigger guard assembly which has been partially disassembled, portions being illustrated in phantom, said trigger guard assembly being employed for a third embodiment of a lockable firearm safety in accordance with the present invention; 
     FIG. 14 is a perspective view of a lock unit and key employed in the trigger guard assembly of FIG. 13; 
     FIG. 15 is a sectional view taken along the line  15 — 15  of FIG. 13 with the lock unit of FIG. 14 being assembled in place, said lockable firearm assembly being partly broken away and partly illustrated in phantom; 
     FIG. 16 is an exploded perspective fragmentary view, partly in phantom and partly broken away, of a fourth embodiment of a lockable firearm safety in accordance with the present invention; 
     FIG. 17A is a left end view and a corresponding schematic view of the lockable firearm safety of FIG. 16 illustrating a fire position thereof; 
     FIG. 17B is a left end view and a corresponding schematic view of the lockable safety assembly of FIG. 16 illustrating a safety unlocked position thereof; 
     FIG. 17C is a left end view and a corresponding schematic view of the lockable firearm safety of FIG. 16 illustrating a safety locked position thereof; and 
     FIG. 18 is an enlarged top plan view, partly in phantom, of the key of FIG. 16 illustrating a hinged feature thereof. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the drawings, wherein like numerals represent like parts throughout the several figures, a lockable firearm safety in accordance with the present invention is generally designated by the numerals  10  (FIGS.  1 - 2 ),  110  (FIG.  12 ),  210  (FIG. 15) and  310  (FIG.  16 ). The lockable firearm safety employs a key  12 ,  112  (FIGS. 11,  12 ),  212  (FIG. 14)  312  (FIG. 18) for transforming the firearm between an unlocked and a locked safety position, as will be detailed below. The safety may assume a wide variety of forms and is configured, as will be described below, to be readily incorporated into conventional firearms to provide a trigger block-type safety  10  or a hammer block-type safety  110  which can be locked to prevent the safety from being displaced to the fire position. The safety may also employ a conventional lock mechanism, such as the embodiment of safety  210 , or a key retaining mechanism, such as the embodiment of safety  310 . 
     A number of firearms employ a safety in the form of a displaceable bolt which functions to mechanically block or obstruct the discharge of the firearm when the trigger is pulled. The bolt is mounted in a transverse orientation relative to the barrel of the firearm. For a hammer block-type safety, the bolt is configured to, upon selective positioning, block the hammer from striking the firing pin and in a second position allow the hammer to strike the firing pin without any interference. The bolt is typically manually displaced from the fire position to the safety position. In the safety position, the bolt blocks the hammer from striking the firing pin. For a trigger block-type safety, the bolt interacts with the trigger to limit rearward pivot of the trigger when the bolt is in the safety position, and the trigger is free to be pulled or to discharge the firearm when the bolt is in the fire position. 
     A representative trigger block safety which is illustrated and represents the respective conventional trigger block and safety and, for the illustrated views, the lockable firearm safety  10  in accordance with the present invention is illustrated in FIGS.  1 - 3 . A trigger guard assembly  20  includes a trigger guard  22  for a trigger  24 . The trigger guard assembly is typically mounted to the underside of the receiver (not illustrated) in a conventional fashion with the trigger  24  being pivotally mounted by means of a pin  26 . The trigger  24  is pulled in a conventional fashion to cause the hammer (not illustrated) to move forward and strike the firing pin (not illustrated). 
     The safety bolt  50  is received in a cross-bore  51  of the trigger guard or in some embodiments a cross-bore of the receiver. With reference to FIGS.  3 - 7 , the safety bolt  50  includes opposed ends  52  and  54  typically designated as respective safe and fire ends. End  52  typically is ribbed to facilitate depressing the bolt transversely. The safe end projects transversely from the guard or receiver to indicate that the bolt is in the safe position. When the bolt is depressed inwardly, the bolt moves to a fire position. The transverse positions of the safety bolt are defined by respective axially spaced, safe and fire groove-like recesses  56  and  58 . 
     A pin or detent  60  controlled by a plunger  62  and spring  64  is mounted in a bore  66  of the trigger guard of the receiver. Plunger bore  66  intersects cross-bore  51  in perpendicular relationship. The detent is spring-biased for projection into a recess  56 ,  58  to define a generally semi-stable bolt position. However, upon manual depression of the bolt  50  between the safe and the fire positions, the detent  60  is sufficiently resiliently biased and the recess defining walls of the recesses are contoured to permit the detent to cam over the rib-like boundary between one recess to the opposing recess to thereby provide a well-defined semi-stable safe and fire position for the safety bolt  50 . 
     The safety bolt  50  is configured as required for cooperation with the various elements of the trigger/hammer assembly to either allow the hammer to move forward to a position for firing the firearm or to block such movement. For example, the trigger may have a rearward integral shoulder or tab  28  which engages a shoulder surface  53  of the bolt in the safety position and thereby prevents the trigger from moving to discharge the firearm. In the fire position, the tab  28  is free to pivot into the recess  56  without restriction. The techniques and structures for accomplishing this bistable function are quite extensive and are not the specific subject of the invention. 
     The safety bolt  50  is also provided with a well-like lock recess  70  (FIGS.  4 - 6 ) which has a deeper radial depth than that of the fire and safety recesses  56 ,  58 . The recess  70  may be somewhat exaggerated in the FIG. 4 drawing. In addition, a transverse key slot  72  extends through the fire end of the bolt. The slot  72  is configured to accept the key blade  14  of key  12 . When the bolt  50  is in the safe position, a key  12  may be inserted into the slot  72 . The bolt is then rotated approximately 180° so that the detent  60  engages in the well under the bias of spring  64 . The sides of the well are sufficiently steep so that the detent is not easily dislodged from the well, upon either torquing the bolt or applying an axial force to the bolt  50 . Consequently, the bolt cannot be manually transformed to the fire position. Thus, the blocking bolt is locked in the safety position. 
     The operation of the lockable firearm safety is illustrated in FIGS.  7 A- 7 E which show the relative positions of the detent  60 , safe recess  56 , fire recess  58 , lock recess  70  and key slot  72 . FIG. 7A illustrates the safety bolt in the fire position. FIG. 7B illustrates the safety bolt in the safe position with the safety bolt being unlocked and the arrow representing the direction of axial displacement. FIG. 7C illustrates the safety bolt in the safe locked position with the arrow representing the direction of rotation from FIG. 7B to FIG.  7 C. FIG. 7D illustrates the safety bolt upon return to the safety and unlocked position with the arrow illustrating the direction of rotation from FIG. 7C to FIG.  7 D. FIG. 7E illustrates the position of the safety bolt in the fire position with the arrow representing the direction of axial displacement to the fire position. The safety bolt is configured so that it cannot be locked in the fire position and can only be locked and unlocked in the safety position. It should also be appreciated that the axial position of the detent  60  relative to the receiver/trigger guard is fixed, while the axial position of the safety bolt is displaceable to achieve the desired safety and fire status for the firearm. 
     The blade  14  of the key is configured so that the key may be inserted into slot  72  so that the blade cams the detent  60  from the well  70 . This permits rotation of the bolt back to the initial safety position (FIG.  7 D). The detent may follow the groove path of recess  56  to the groove position illustrated in FIG.  7 D. This is the normal safety position of the bolt. The bolt is now readily transformable to the fire position by manual depression of the bolt (FIG.  7 E). The detent/groove relationship is such that the detent can be cammed out of the safety recess  56  for reception into the fire recess  58 . 
     It should be appreciated that for additional security, the detent may be replaced by a stack of tumbler pins and the key blade configured so that a sheer line is formed to permit the rotation from the locked to the unlocked position. Likewise, two or more axially spaced stacks of pins (not illustrated) may be employed. 
     With reference to FIGS.  8 - 10  and  12 , lockable hammer block-type safety bolt  150  is illustrated. In this configuration, the bore  151  for the safety bolt extends through the receiver  130 , and the detent bore  166  is implemented at one side at the rear of the receiver. The structures of bolt  150  corresponding to those of bolt  50  are designated by the same two digit numeral preceded by a “1.” For bolt  150 , the safe recess  156  only extends approximately 180° about the periphery to define a rotational path for locking and unlocking the safety bolt. The bolt  150  has a recess  155  which permits the hammer  132  to move forward and strike the firing pin (not illustrated) when the bolt is in the fire position. In the safe position, an appendage on the hammer strikes the shoulder  153  and is thereby obstructed from striking the firing pin. 
     With reference to FIGS.  13 - 15 , a lockable firearm safety  210  employs a lock cylinder  200 . The cylinder comprises a plug  202 , a shell  204  and a bible  206  which houses stacks of pins. A keyway  272  receives a key  212  which is cut to engage the lock pins in a fashion which permits a shear line between the plug and shell to thereby permit rotation of the plug  202  relative to the shell  204 . For comfort and convenience, rather than the usual extension, key  212  preferably has a rounded end with a rotating ring attached for rotating the key blade. The cylinder and key may be custom bitted for each firearm. The lock cylinder is preferably a key-retaining lock which prevents removal of the key unless the cylinder is in the locked rotational position. A tailpiece  250  which functions as a safety bolt projects from the rear of the lock cylinder. A locking lug  251  projects radially from the tailpiece and with respect to the rotational axis of the plug. The tailpiece also forms a channel or recess  255  (FIG. 14) which receives the trigger tab or shoulder  28  when the lock cylinder is transversely displaced to the fire position. In the safe position, the tailpiece has a surface  253  which interferes with the trigger shoulder to obstruct rearward movement of the trigger and prevent firing of the firearm. It should be appreciated that the tailpiece (not illustrated) and/or shell could be configured and positioned to form a hammer block safety. A cap (not illustrated) may be mounted to the end of the tailpiece to provide a pleasing finished appearance. 
     With additional reference to FIG. 13, the trigger guard frame  220  has a keyhole-shaped transverse slot  209  which receives the lock cylinder  200 . The detent assembly comprises a spring-biased plunger  260  which maintains the lock cylinder in safe and fire positions by engaging axially spaced cavities  256 ,  258  formed in the side of the lock cylinder shell. The trigger guard frame  220  includes a slot  261  which receives the locking lug  251  upon rotation of the plug and tailpiece at a given axial position of the lock cylinder  200  constituting the safe position of the firearm. 
     When the firearm is in the safe locked position wherein the lock cylinder is locked, the lug  251  is retained in the slot  261 , and axial displacement of the safety which comprises the lock cylinder, including the tailpiece, is axially limited. The safety can be axially displaced to the fire position by rotating (unlocking) the lock cylinder with the key and transversely axially moving the cylinder to the fire position. In the fire position, the shoulder  28  on the trigger will pivot into the slot on the tailpiece and allow the firearm to fire. It is preferred that the lock cylinder be a key-retaining lock wherein the key will be retained in the cylinder when the firearm is in the fire position and may only be removed from the lock when the locked safety position is obtained. The key will thus always be required to fire the firearm. 
     With reference to FIGS.  16 - 18 , a lockable safety assembly which incorporates a key retaining feature is generally designated by the numeral  310 . A sleeve or liner  340  is closely received in the transverse bore  341  of the receiver or the trigger guard. The sleeve may extend from one end of the bore to an intermediate axial position. The sleeve is internally dimensioned to receive the cross bolt  350  and permit sliding axial and angular displacement relative to the sleeve  340 . The sleeve is secured in fixed relationship with the transverse bore. The bolt  350  has a lock recess  370 , an axial key slot  372  and a detent channel  374  which angularly subtends the semi-circumference of the bolt. An axial channel  376  extends from the opposite end of the detent channel axially inwardly for termination at a dwell position  378  which defines the fire position. The radial depth of lock recess  370  is greater than the radial depth of the channels  374  and  376  and dwell position  378 . The bolt otherwise is configured to selectively interact with the trigger or block the hammer as previously described for bolts  50  and  150 . The outside diameter of the bolt may be stepped to accommodate the liner sleeve  340 . 
     The liner  340  includes an axial slot  342  and a cross slot  344  which angularly subtends to connect with an opposing axial slot  345 . The axial slot terminates in a shoulder  346 . 
     The key  312  has a blade  313  which includes a key lug  314 . The key lug  314  is dimensioned so that it is received in the axial liner slot  342  and axially slides therealong until it reaches the axial position of the cross slot  344 . The axial position also aligns with the lock recess  370 . The lug  314  is contoured to lift the locking detent  360  from the lock recess of the bolt and to allow the bolt to be torqued (the detent pin following channel  374 ). The cross bolt may then be axially displaced to the fire position (the detent pin following channel  376 ) wherein the detent enters the shallow recess  378  at the fire position. The entrance slot  342  and slots  344  and  345  function as a track for the lug  314 . It will be appreciated that the lug  314  is engageable against shoulder  346  in the liner to prevent the key from being withdrawn from the bolt while the bolt is in the fire position. The lug  314  also engages the shoulder  347  of the cross slot  344  until the bolt is angularly returned to the locked safety position. Thus, the key can only be withdrawn when the bolt is returned to the safety position and locked. 
     The fire and safety positions may be visually indicated by indicia, such as color coding or “S” and “F” as illustrated in FIGS.  17 A-C. The sequence of the transformation of the bolt from the fire position as well as the position of the lug  314  relative to track of the liner slots is schematically illustrated in FIG.  17 A. For FIG. 17B, the bolt has been displaced to the safety position but remains unlocked. In FIG. 17C, the bolt has been displaced to the safety locked position so that the key is now free to be removed (the lug  314  can be axially withdrawn from slot  342 ), and the detent is biased into the lock recess of the bolt to lock the bolt in the safety position. The foregoing key retaining feature may also be employed in conjunction with a conventional lock pin assembly and key bitting to provide additional security. 
     It should also be appreciated that, as illustrated in FIG. 18, the key  312  may be hinged to permit the bow portion  315  to be pivoted against the side of the receiver to minimize any interference with the operation of the firearm. When it is desired to use the key to rotate the bolt to permit transformation between the fire and safety positions, the bow  315  may be pivoted axially outwardly to facilitate an application of torque to the bolt via the key. 
     It will be appreciated that other forms of the lockable safety may be employed to provide for a secure lock position in the safety mode and allow the firearm to be unlocked and the firearm used in a conventional manner in conjunction with the block-type safety. 
     While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.