Abstract:
The invention relates to a drop-safety mechanism for a firearm having a pivot-mounted, trigger, said trigger being designed as an arm of a double lever, the other arm of which supports a counterweight that can be displaced between a rest position and a functional position. The counterweight is resiliently pre-tensioned in the rest position and strikes on a part of the firearm in the functional position to block the trigger from unintended firing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Phase application of International Application No. PCT/AT2010/000151 filed May 6, 2010 which claims priority to Austrian Patent Application Nos. A 1019/2009 filed Jun. 30, 2009; A 1020/2009 filed Jun. 30, 2009; and A 1140/2009 filed Jul. 21, 2009. 
     BACKGROUND  
     The present invention relates to a drop-safety mechanism for a firearm with a pivot-mounted trigger. 
     Drop-safety mechanisms are used to prevent discharge in case of a collision impact on the weapon, e.g., if it lands on the ground with its stock or receives an impact on the stock. Without a drop-safety mechanism, the trigger could move backward due to its moment of inertia and fire a shot. Therefore movable masses are provided for the weapon that move in the same manner as the trigger in such a case and insert themselves in front of a catch in order to block it. 
     In known drop-safety mechanisms, the movable mass is supported on the housing, which requires a relatively large amount of space. The invention has the objective of creating a more compact solution. 
     SUMMARY 
     This objective is achieved according to the invention in that the trigger is constructed as part of a two-armed lever, whose other arm supports a counterweight, movable between a rest position and a functional position, that is pretensioned into the rest position and strikes against a part of the firearm in the functional position in order to block the trigger. 
     In this manner, the drop-safety mechanism is supported directly on the trigger, which results in an exceedingly compact, free-moving and malfunction-resistant mechanism. 
     The counterweight is preferably pivot-mounted on the aforementioned arm, a compression spring acting between a shoulder of the counterweight and a shoulder of the arm, which results in a particularly safe operation. 
     A preferred embodiment of the invention is distinguished in that the aforementioned part of the firearm, against which the counterweight strikes in the functional position, is a part of the hand-cocking mechanism of the firearm. Thereby the already existing part of the hand-cocking mechanism can serve as a stop, which further reduces the space requirement for the drop-safety mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in detail below with reference to an exemplary embodiment illustrated in the attached drawings. In the drawings: 
         FIG. 1  shows the hand-cocking and trigger mechanism of a firearm with a drop-safety mechanism according to the invention in cross section; and 
         FIGS. 2 and 3  show the drop-safety mechanism of  FIG. 1  in detail in the rest position ( FIG. 2 ) and the functional position ( FIG. 3 ). 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows the rear part of a firing pin  1 , a trigger mechanism  2 , a cocking and uncocking mechanism  3  and (in part) a housing  4  of a firearm (not shown in further detail). The firing pin  1  acts on a cartridge in the chamber of a rifle barrel and is guided for this purpose in a rotary piston, for example, which parts are known to those in the art and are therefore not shown in detail here. 
     The firing pin  1  is subjected to a force to the left in the drawing by a firing pin spring  5  (indicated schematically) and is engaged with a firing pin tab  6  at point  7  on a catch  8 . The catch  8  is seated movably, in both the longitudinal and the transverse directions of the firing pin, by a bearing journal  9  in elongated holes of the housing  4 . Thus the catch  8  can first be released from the firing pin  1  by means of the trigger mechanism  2  to fire a shot, so that the firing pin moves to the left by the force of the firing pin spring  5  to collide with the cartridge; second, the catch  8  can thus also be moved or displaced in the longitudinal direction between two positions, specifically, an unsecured or cocked position ( FIGS. 2 and 3 ), in which the catch holds the firing pin  1  cocked against the force of the firing pin spring  5 , and an uncocked safety position ( FIG. 1 ) in which the catch  8  is displaced to the left in the drawing, in order to relieve the tension of the firing pin spring  5 . 
     To absorb the above-mentioned displacement motion of the catch  8 , the trigger mechanism  2  comprises an intermediate element in the form of a catch rod  10  that is linearly guided in the housing  4  approximately vertically and supports a ball bearing-seated roller  11  at its upper end, on which the catch  8  can slide back and forth. The catch rod  10  in turn is engaged at a shoulder  12  on a click-stop edge  13  formed on a shoulder  14  of the trigger  15 . The trigger  15  is pivotably seated at  16  on the housing  4  and, when actuated, moves the click-stop edge  13  away from the catch rod  10 , so that the latter is moved downward and releases the catch  8  from the firing pin  1 , whereby the shot is fired. The extent of the engagement overlap between the shoulder  12  of the catch rod  10  and the click-stop edge  13  of the trigger  15  can be adjusted by means of an adjusting screw  17 . 
     The trigger  15  with its click-stop edge  13  can be integrally formed or—as shown—formed as two parts adjustable relative to one another, such as a first part comprising the actual trigger blade  18  and a second part comprising the shoulder  14  with the click-stop edge  13 . 
     The trigger  18  is equipped with a drop-safety mechanism  19 , which will be described in detail below. The trigger  15  can further be equipped with a bolt catch  20  for triggering a rotary piston action, as known to those in the art. 
     The cocking and uncocking mechanism  3  comprises an actuator element  21  in the form of a cocking slide  21  slidably seated on the outside of the housing  4  with a thumb-press surface  22 , which acts via a linkage  23  on the catch  8  in order to move it back and forth in the longitudinal direction of the firing pin between its two positions ( FIGS. 1 ,  2 / 3 ). The linkage  23  contains a motion link  24 , via which the force/distance transmission ratio between the actuator element  21  and catch  8  can be adjusted. 
     The motion link  24  comprises a pivoting crank  25  that can be pivoted by the cocking slide  21  via a connecting rod  26  and bears a control cam  27  on its outer periphery. A sensing linkage  28  with a ball bearing-seated cam follower  29  rolls over the control cam  27  and translates the shape of the control cam  27  into a movement of the catch  8  via a housing-seated two-armed lever  30  that engages with a pin  31  of the catch  8 . 
     The pivoting crank  25  is also equipped with an auxiliary linkage guide  32  in the form of a groove guide that is located behind the control cam  27  and with which the sensing linkage  28  engages by means of a retaining pin  33  projecting past the cam follower  29 . Thereby a forced contact of the cam follower  29  on the control cam  27  is assured in every operating state. 
     When the cocking slide  21  is moved from right to left, the pivoting crank  25  swings downward, the sensing link  28  slides to the left on the control cam  27  and the catch  8  is moved to the right by the lever  29  against the force of the firing pin spring  5 . With the aid of a push button  36  on the cocking slide  21 , a self-locking latch  37  for locking the connecting rod  26  in the cocked position C can again be disengaged. 
       FIGS. 2 and 3  show the drop-safety mechanism  19  of the trigger  18  in detail. For this mechanism, the trigger blade  18  is constructed as one arm of a two-armed lever with respect to its articulation point  16 , the other arm  38  of the lever supporting a counterweight  39 . The counterweight  39  is pivot-mounted at  40  on the end of the arm  38 , the pivot axis  40  running parallel to the pivot axis  16 . The counterweight  39  is pretensioned into the rest position as shown in  FIG. 2 , in which it is moved forward in the shooting direction of the weapon, by means of a compression spring  41  that acts between a shoulder  42  of the counterweight and a shoulder  43  of the arm  38 . 
     If a collision impact is exerted from the rear onto the firearm, the stock for example, or if the firearm falls and lands on its stock, the trigger  18  has the tendency to move to the right in the drawing, pivoting about the support point  16 , due to its inertia. Due to the drop-safety mechanism  19 , the counterweight  39  then moves—overcoming the bias tension of the spring  41  —in the same direction as the trigger  18  into the functional position shown in  FIG. 3 . In this position, the counterweight  39  strikes a part of the firearm, e.g., a catch or a protrusion in the housing of the firearm or—as in the example shown—against a projection  44  of the lever  30  or the end of the sensing linkage  28 . Thereby a movement of the trigger  18  is blocked, and unintended firing due to a collision impact is prevented. 
     A bias spring (not shown) drawn onto a guide rod  45  and supported on a housing bearing  46  can also act on the lever arm  38  of the trigger  18  in order to realize a double-set trigger. 
     The invention is accordingly not limited to the illustrated embodiments, but instead comprises all variants and modifications that fall within the scope of the appended claims.