Abstract:
A pistol has a locking mechanism that locks the trigger mechanism of the pistol if an unauthorized person attempts to fire the pistol. The locking mechanism includes an identification unit to detect an identification signal and a control unit that compares the inputted signal with a stored identification pattern. An electromechanical actuator device actuates a locking element that can be moved into a locked position and into an unlocked position, which in the locked position locks the trigger tongue of the pistol. The pistol locking mechanism has a plurality of display elements that display the operating status of the locking mechanism.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to handguns and, more particularly, to a pistol having a locking mechanism to lock and unlock the pistol trigger mechanism. 
     2. Description of the Currently Available Technology 
     U.S. Pat. No. 5,502,915 describes a revolver that includes a locking device that blocks the hammer if an attempt to operate the revolver is made by an unauthorized person. The device has a scanner on the revolver grip that identifies the palm print of the shooter and compares it to a pattern stored in memory. If the scanned print matches the print stored in memory, the hammer is unlocked by a solenoid so that the weapon is ready for firing. However, this solution cannot be used on most automatic pistols since the magazine must be inserted into the pistol grip and, therefore, there would be no room for the locking device. 
     Additional locking devices for handguns that can be fired only by authorized users are described in DE-A-43 03 333 and U.S. Pat. Nos. 5,603,179; 5,022,175; and 4,970,819. 
     Therefore, it is an object of the invention to create a locking mechanism for a pistol, e.g., an automatic pistol, that locks the trigger mechanism of the pistol if an unauthorized person attempts to fire the pistol. The invention teaches that this object can be accomplished by the features disclosed hereinbelow. 
     SUMMARY OF THE INVENTION 
     A pistol locking mechanism is provided for reversibly locking the trigger mechanism of a pistol if an attempt is made by an unauthorized person to fire the pistol. The locking mechanism comprises an identification unit to detect an identification signal; a control unit connected with the identification unit that compares the inputted signal with a stored identification code or number; an actuator device having a motor, e.g., a geared motor, connected to the control unit which is connected, e.g., by a threaded spindle-nut connection, with a mechanical locking element movable between a locked position locking the trigger tongue of the pistol and an unlocked position; a battery is preferably present to supply power to the locking mechanism; and a plurality of display elements to display the operating status of the locking mechanism. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in greater detail below with reference to the exemplary embodiments illustrated in the accompanying drawings, in which: 
     FIG. 1 shows a schematic side view of a first embodiment of the invention in partial section, and 
     FIGS. 2 to  4  show partial sections of three additional exemplary embodiments of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of the description hereinafter, spacial terms such as “left”, “right”, etc. shall relate to the invention as it is oriented in the Figures. However, it is to be understood that the invention may assume various alternative variations, except where expressly specified to the contrary. 
     FIG. 1 is a schematic illustration showing in partial section a detail of a side view of a pistol  10  with a locking mechanism  11  of the invention. The pistol  10  has a grip body  12  with a molded trigger guard  13  into which a trigger tongue  14  projects. The tongue  14  is rotationally mounted on a cross pin  15  and actuates a trigger rail (not shown) in conventional manner. The front of the tongue  14  has an approximately cylindrical part  16  that runs concentric to the pin  15  and has an index notch  17 . The locking mechanism  11  is preferably installed below the barrel and for the most part in front of the trigger guard  13 . 
     The mechanism  11  comprises an identification unit  20  having a keypad with a plurality, e.g., four, keys  21 . One key, e.g., the first or rightmost key, can be used to electronically enter signals, e.g., numbers, e.g., 1, 2 or 3 by pressing it once, twice or three times, respectively. The next two keys  21  can be used to enter or code the numbers 4 to 6 and 7 to 9, respectively. The fourth or leftmost key  21  can be used to enter the number 0 and to select the functions “reset” and “save”. The mechanism  11  is preferably initially turned on by pressing any key. Pressing the fourth key  21  (reset) twice locks the trigger tongue  14  and switches the electronic system to standby. The keys  21  can be used to enter a user personal identification number (PIN) code or alphanumeric code. The user can also select the length of time the pistol will remain unlocked. After the expiration of the unlocked period or when the pistol is deactivated, the trigger mechanism is locked automatically. The identification unit  20  is in electronic communication, e.g., by wires or electronic circuit, with a power source, e.g., a battery  23 , to supply electrical power to the identification source  20 . The battery  23  is also in electronic communication with a charge monitoring unit  50  for monitoring the charge remaining in the battery. 
     The identification unit  20  preferably has three light-emitting diodes  22  of different colors to indicate the operating status of the mechanism  11 . For example, one diode  22  lights when the mechanism  11  is activated and the trigger tongue  14  is locked. The second diode  22  lights when the trigger tongue  14  is unlocked. The third diode lights when the battery  23  needs to be replaced, because its charge is almost depleted. In the absence of a timely response to this signal, before the battery  23  is fully discharged and depending on the application in which the pistol is being used, the mechanism  11  switches either to lock the trigger tongue  14  (for civilian use) or to unlock the trigger tongue  14  for an unlimited period of time (for police use) when the battery power drops below a preset, specified value. 
     The identification unit  20  is in electronic communication with a control unit  24  having an electronic memory  25  which stores the code that must be entered to unlock the trigger tongue  14 , The control unit  24  compares the code that has just been inputted into the identification unit  20  with the code stored in the memory  25 . If the codes match, the control unit  24  actuates an actuator device, e.g., an electric motor  27 , via an electronic control system  26 . The battery  23  is also in electronic communication with the control unit  24  and motor  27  to supply electrical power to these elements. In a preferred embodiment, the motor  27 , via a planetary reduction gear train  28 , drives a threaded spindle  29  that is screwed into a nut thread  30  of a prismatic bolt  31 . The bolt  31  is guided in guides  32  so that it can move longitudinally but non-rotationally. A locking element  33  is movably mounted in the bolt  31 . The locking element  34  is biased toward the tongue  14  by a spring  34 . When the tongue  14  is in a base position and the mechanism  11  is in the locked position, the locking element  33  is engaged in the notch  17  and locks the trigger tongue  14  to prevent movement of the trigger tongue  14 . 
     If an authorized user or shooter wishes to fire the pistol  10 , he first turns on the mechanism  11  by pressing one of the keys  21  and then enters his PIN code via the keys  21 . The inputted code is compared by the control unit  24  to the code stored in memory  25  and, if the two codes are the same, the bolt  31  is retracted from the illustrated locked position, e.g., right most position in FIG. 1, by the motor  27  so that the locking element  33  is retracted from the notch  17  to release the trigger tongue  14 , i.e., allow the trigger tongue  14  to rotate. 
     In addition, an infrared sensor  39  with an infrared emitter  40  and a receiver  41  can be installed on the front end of the trigger guard  13  and powered in conventional manner by the battery  23 . The sensor  39  is in electronic communication with the control unit  24  and releases the control unit  24  to unlock the pistol  10  only if, before the code is entered via the keys  21 , one of the shooter&#39;s fingers  42  is engaged in the trigger guard  13 . When the shooter&#39;s finger  42  is removed from the trigger guard  13 , the signal from the sensor  39  brings about an automatic locking of the pistol  10  by the control unit  24 . Therefore if the pistol  10  falls out of the shooter&#39;s hand or is taken from him, the trigger tongue  14  is locked automatically. 
     Instead of the keys  21 , or in addition to them, the identification unit  20  can also include a fingerprint scanner  46 . In that case, the memory  25  stores the pattern of a fingerprint, for right-handed shooters, for example, the tip of the index finger of the left hand. The scanned fingerprint is compared to the pattern stored in the unit  24  and, if the two prints match, the locking mechanism  11  is unlocked, i.e., the locking element  33  is withdrawn from the notch  17 . This variant has the advantage of easier and faster operation. The identification is also accurate, reliable and secure, and relates to only one individual. 
     FIGS. 2 to  4  illustrate additional embodiments of the invention, whereby the elements  20  to  26  and/or  46  can be realized in a manner that is identical to the elements of the embodiment illustrated in FIG.  1 . In the embodiments illustrated in FIGS. 2 and 3, a hammer  49  is locked by a locking mechanism  111 . For that purpose, the hammer  49  has an index notch  50 , in which, in the locked position, one, e.g., a first, arm  51  of a spring-loaded, two-armed locking lever  52  is engaged. In the mechanism  111  illustrated in FIG. 2, the lever  52  can be pivoted into the unlocked position by a solenoid  53  against the force of a spring  54 . The solenoid  53  is configured to engage a second arm  55  of the lever  52 . A capacitor is preferably installed in the electronic control system  26 . The electronic control system  26  (FIG. 1) actuates the solenoid  53  in conventional manner, such that when the solenoid  53  is activated, the lever  52  rotates clockwise as shown in FIG. 2 so that the first arm  51  is rotated out of the notch  50  to allow the hammer  49  to be cocked. 
     In a locking mechanism  211  embodiment illustrated in FIG. 3, the solenoid  53  of FIG. 2 is replaced by a geared motor  27  and gear train  28  as shown in FIG. 1 having an output shaft  59  oriented substantially parallel to an axis of rotation  60  of the hammer  49 . The output shaft  59  supports an eccentric pin  61 . In the unlocked position, the pin  61  presses on the second arm  55  to rotate the first arm  51  out of the notch  50 . This variant has the advantage that current is required only to switch from the locked position into the unlocked position and vice-versa. The shaft  59  thereby rotates by 1800 during each operation. 
     A locking mechanism  311  variant illustrated in FIG. 4 is analogous to the one illustrated in FIG.  3 . In this case, in the locked position, the eccentric pin  61  pushes a spring-loaded trigger rail  65  out of engagement with the hammer  49  to allow the hammer  49  to be cocked. 
     Having described the presently preferred embodiments of the invention, it is to be understood that the invention may be otherwise embodied within the scope of the appended claims.