Abstract:
A mechanism for a repeating firearm has a body pivotably mounted within the receiver and movable between a first position where it blocks motion of the bolt carrier, and a second position where it engages either the trigger or the hammer to prevent discharge. In operation the body is moved from the first position to the second to release the bolt carrier, which moves into battery. The body is then allowed to move out of the second position toward the first position. The rife may be discharged by a pull of the trigger, and the bolt carrier moves out of battery and is arrested by the body before moving back to battery. If the body is maintained in the second position during operation its engagement with the trigger or hammer prevents discharge of the firearm.

Description:
FIELD OF THE INVENTION 
     This invention concerns repeating firearms, such as magazine fed repeating rifles. 
     BACKGROUND 
     Modern sporting rifles may operate in a mode in which a single pull of the trigger discharges a round, and a portion of the energy of the discharging round is harnessed (via recoil, blowback or gas operation) to extract and eject the spent cartridge, cock the hammer, strip a live round from the ammunition magazine and chamber the live round, ready to be discharged by another pull of the trigger. 
     Repeating firearms, for example, repeating rifles, are also of interest to modern shooters. In a repeating firearm, the shooter must take action to complete the loading cycle. 
     SUMMARY 
     The invention concerns a mechanism positionable in a receiver of a firearm, such as a rifle, for holding a bolt carrier in an open position. The firearm comprises a hammer movably mounted substantially within the receiver and a trigger movably mounted substantially within the receiver. In an example embodiment, the mechanism comprises a body movably mountable substantially within the receiver. The body has a first and a second surface thereon. The body is movable between a first position, wherein the first surface engages and holds the bolt carrier in the open position, and a second position, wherein the first surface does not engage the bolt carrier. The second surface is engageable with one of the trigger or the hammer when the body is in the second position so as to prevent a discharge of the firearm, unless the body has been manipulated by the shooter. In this example embodiment, a spring acts between the receiver and the body for biasing the body into the first position. 
     By way of example, the mechanism may further comprise a pin mountable on the receiver. The body is mountable on the pin for pivoting movement between the first and the second positions. A tab may be attached to the body in spaced relation to the pin for manually moving the body between the first and the second positions. 
     In a particular example embodiment, a boss is positioned on the body and projects transversely therefrom. The second surface is positioned on the boss. By way of further example, a finger projects from the trigger. The finger engages the second surface on the boss when the body is in the second position and thereby prevents motion of the trigger. 
     In another example embodiment, a notch is positioned in the hammer. The notch is aligned with the boss when the body is not in the second position and thereby permits motion of the hammer to discharge the firearm. The notch is out of alignment with the boss when the body is in the second position. The hammer thereby is engageable with the second surface of the boss to prevent discharge of the firearm. 
     The invention also encompasses a repeating firearm, such as a repeating rifle. In one example embodiment, the repeating firearm comprises a receiver. A barrel is mounted on the receiver. A bolt carrier is mounted on the receiver and is movable between an open position and a closed position wherein the bolt carrier engages a chamber of the barrel. A hammer is movably mounted substantially within the receiver. A trigger is movably mounted substantially within the receiver. A body is movably mounted substantially within the receiver. The body has a first and a second surface thereon. The body is movable between a first position wherein the first surface engages and holds the bolt carrier in the open position, and a second position wherein the first surface does not engage the bolt carrier. The second surface is engageable with the trigger when the body is in the second position so as to prevent motion of the trigger and thereby a discharge of the firearm. In this example embodiment, a spring acts between the receiver and the body for biasing the body into the first position. 
     In a particular example embodiment, a pin is mounted on the receiver. The body is mounted on the pin for pivoting movement between the first and the second positions. The pin is mounted on an outside surface of the receiver in one example embodiment. By way of example, a tab is attached to the body in spaced relation to the pin. The tab extends outside of the receiver for manually moving the body between the first and the second positions. 
     By way of example, a boss is positioned on the body and projects transversely therefrom. The second surface is positioned on the boss. In another example, a finger projects from the trigger. The finger engages the second surface on the boss when the body is in the second position and thereby prevents motion of the trigger. 
     In another example embodiment, a notch is positioned in the hammer. The notch is aligned with the boss when the body is not in the second position and thereby permits motion of the hammer to discharge the firearm. The notch is out of alignment with the boss when the body is in the second position. The hammer thereby is engageable with the second surface of the boss to prevent discharge of the firearm. 
     By way of example, the firearm may further comprise a magazine well positioned within the receiver. An ammunition magazine is removably positionable within the magazine well. 
     The invention further comprises a repeating firearm, such as a repeating rifle. In a particular example embodiment, the firearm comprises a receiver. A barrel is mounted on the receiver. A bolt carrier is mounted on the receiver and is movable between an open position and a closed position wherein the bolt carrier engages a chamber of the barrel. A hammer is movably mounted substantially within the receiver. A trigger is movably mounted substantially within the receiver. A body is movably mounted substantially within the receiver. The body has a first and a second surface thereon. The body is movable between a first position, wherein the first surface engages and holds the bolt carrier in the open position, and a second position, wherein the first surface does not engage the bolt carrier. The second surface is engageable with the hammer when the body is in the second position so as to inhibit motion of the hammer and thereby prevent a discharge of the firearm. A spring acts between the receiver and the body for biasing the body into the first position. 
     By way of example, a pin is mounted on the receiver. The body is mounted on the pin for pivoting movement between the first and the second positions. In a particular example embodiment, the pin is mounted on an outside surface of the receiver. By way of example, a tab is attached to the body in spaced relation to the pin. The tab extends outside of the receiver for manually moving the body between the first and the second positions. 
     In a further example, the body comprises a boss positioned on the body. The boss projects transversely therefrom. In this example the second surface is positioned on the boss. 
     In an example embodiment, the firearm further comprises a notch positioned in the hammer. The notch is aligned with the boss when the body is not in the second position and thereby permits motion of the hammer to discharge the firearm. The notch is out of alignment with the boss when the body is in the second position. The hammer thereby is engageable with the second surface of the boss to prevent discharge of the firearm. 
     In another example embodiment, the firearm further comprises a magazine well positioned within the receiver. An ammunition magazine is removably positionable within the magazine well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a right side view of a repeating firearm according to the invention; 
         FIG. 2  is a partial isometric view of the receiver of the firearm shown in  FIG. 1  with an example embodiment of the mechanism according to the invention; 
         FIG. 3  is an isometric view of an example mechanism embodiment according to the invention; 
         FIG. 4  is an isometric view of an example trigger used with the mechanism of  FIG. 3 ; 
         FIG. 5  is a partial longitudinal sectional view of the firearm shown in  FIG. 1  having the example mechanism shown in  FIG. 3 ; 
         FIG. 5A  is a left side view of the firearm shown in  FIG. 1 ; 
         FIGS. 6 and 7  are partial isometric views of the receiver and mechanism of  FIG. 3  and the trigger of  FIG. 4 ; 
         FIG. 8  is a partial isometric view of the receiver of the firearm shown in  FIG. 1  with another example embodiment of the mechanism according to the invention; 
         FIG. 9  is an isometric view of another example mechanism embodiment according to the invention; 
         FIG. 10  is an isometric view of an example hammer used with the mechanism of  FIG. 9 ; 
         FIG. 11  is a partial longitudinal sectional view of the firearm shown in  FIG. 1  having the example mechanism shown in  FIG. 9  and the hammer shown in  FIG. 10 ; and 
         FIGS. 12 and 13  are partial longitudinal sectional views of the receiver, mechanism of  FIG. 9  and hammer of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an example firearm according to the invention in the form of a repeating rifle  10 . Rifle  10  comprises a receiver  12 , a bolt carrier  14  mounted on the receiver, and a barrel  16  also mounted on the receiver. Barrel  16  has a chamber  18  (shown in  FIG. 5 ) that is engaged by the bolt carrier  14  when it is in the closed position (shown in  FIG. 1 ), the bolt carrier  14  being movable relatively to the receiver between the closed position and an open position (shown in  FIG. 5 ). Rifle  10  further includes a magazine well  20  that receives an ammunition magazine  22 . 
     As shown in  FIG. 2 , a hammer  24  is mounted substantially within the receiver  12  and is pivotable on a pin  26 . Hammer  24  is biased in a clockwise direction (when viewed from the right side of the rifle) by a spring  28  to fall upon a firing pin  29  in the bolt carrier  14  (see  FIG. 5 ) when released by a pull of the trigger  30 . As shown in  FIG. 2 , trigger  30  is mounted substantially within receiver  12  and pivots on a pin  32 . Trigger  30  is biased in a counterclockwise direction by a spring  34 . 
       FIG. 2  shows one example embodiment of a mechanism  36  for holding the bolt carrier  14  in an open position. In this embodiment, mechanism  36  comprises a body  38  movably mounted substantially within the receiver  12 . Body  38  pivots on a pin  40  between a first position (shown), where it is engageable with the bolt carrier  14  (see  FIG. 5 ) and a second position (see  FIG. 7 ), where it is not engageable with the bolt carrier. As explained further below, when body  38  is in the second position it prevents discharge of the rifle. With reference again to  FIG. 2 , a spring  42  acts between the receiver  12  and the body  38  to bias the body toward the first position where it is engageable with the bolt carrier. In this particular example, the spring  42  is a coil spring positioned distally to the pivot pin  40 , but other spring biasing configurations are of course feasible. 
       FIG. 3  shows body  38  in detail as comprising a first surface  44  that is engageable with the bolt carrier  14  (see  FIG. 5 ) when the body  38  is in the first position, and a second surface  46  that engages trigger  30  when the body  38  is in the second position (see  FIG. 7 ). The trigger engaging surface  46  is positioned on a boss  48  that projects transversely from the body  38 . A tab  50  is attached to body  38  in spaced relation to pin  40 . As shown in  FIG. 5A , the tab  50  extends to the outside of the receiver  12  to permit manual actuation of body  38  between the first and second positions. Pin  40  is mounted on the outside of receiver  12  on lugs  52 . 
       FIG. 4  shows trigger  30  in detail. In mechanism example  36 , trigger  30  includes a finger  54  that projects from the trigger and is offset from the trigger pin  32 . When trigger  30  is pulled and pivots about its pin  32 , the finger  54  moves toward the body  38  due to its offset from the pin  32 . As described below, finger  54  will engage the second surface  46  on boss  48  of body  38  when the body is in the second position, i.e., the position where the first surface  44  of body  38  is not engageable with the bolt carrier  14 . 
     Operation of the rifle  10  and mechanism  36  are now described with reference to  FIGS. 5-7 .  FIG. 5  shows a portion of the receiver  12 , barrel  16 , and chamber  18  of rifle  10  with the bolt carrier  14  held in the open position by body  38 . Body  38  is in the first position wherein the first surface  44  engages and blocks motion of the bolt carrier toward chamber  18  under the biasing force of a return spring (not shown). Rifle  10  may be fired by first manually depressing tab  50 . This pivots body  38  about an axis  56  coaxial with pin  40 , moving the body  38  into the second position (see  FIG. 7 ) and thereby releasing the bolt carrier  14 , the first surface  44  no longer engaging the bolt carrier. Biased by its return spring (not shown), bolt carrier  14  moves toward chamber  18 , strips a round from magazine  22  received in magazine well  20 , and chambers the round in chamber  18 . 
     If tab  50  is then released, the body  38  pivots out of the second position under the force of biasing spring  42  into engagement with the bottom of the bolt carrier  14  and near the first position as shown in  FIG. 6 . When body  38  is in this position the boss  48  is out of alignment with the finger  54  extending from trigger  30 . Finger  54  of trigger  30  thus will not engage the second surface  46  when the trigger is pulled, and pulling trigger  30  will discharge the rifle. As the round is discharged, the bolt carrier  14  is driven back away from the chamber  18  against its return spring (for example by recoil, blow-back or gas operation). The spent cartridge is extracted from the chamber and ejected. The bolt carrier  14  passes over the body  38  as it travels away from the chamber  18 . Body  38  then pivots fully back to the first position under the force of its biasing spring  42  when the bolt carrier  14  clears the body. When the bolt carrier reaches the end of its travel its return spring forces it forward toward the chamber  18 . However, its motion is arrested by the body  38 , the first surface  44  again engaging the bolt carrier  14  as depicted in  FIG. 5 . The next round may be loaded by depressing the tab  50  to release the bolt carrier and chamber another round. The round may be fired by releasing tab  50  and pulling trigger  30 . 
     However, if the tab  50  is not released, but is continuously depressed after the bolt carrier is released, then the body  38  is maintained in the second position shown in  FIG. 7 . With body  38  in the second position, boss  48  aligns with finger  54 . When the trigger  30  is pulled, engagement between the finger  54  and the second surface  46  on boss  48  prevents rotation of the trigger about trigger pin  32 , thereby preventing discharge of the rifle. As shown in  FIG. 6 , release of the tab  50  permits the body  38  to pivot out of the second position back near the first position, moving boss  48  out of alignment with finger  54  of trigger  30  and permitting the trigger to be pulled to discharge the next round. 
       FIG. 8  shows another example mechanism embodiment  60  for holding the bolt carrier in an open position. Mechanism  60  comprises a body  62  movably mounted substantially within the receiver  12 . Body  62  pivots on a pin  64  between a first position (shown, see also  FIG. 11 ), where it is engageable with the bolt carrier  14 , and a second position, where it is not engageable with the bolt carrier (see  FIG. 13 ). As explained further below, when body  62  is in the second position it prevents discharge of the rifle. A spring  66  acts between the receiver  12  and the body  62  to bias the body toward the first position where it is engageable with the bolt carrier. In this particular example, the spring  66  is a coil spring positioned distally to the pivot pin  64 , but other spring biasing configurations are of course feasible. 
     As shown in  FIG. 8 , a hammer  68  is mounted substantially within the receiver  12  and is pivotable on a pin  70 . Hammer  68  is biased in a clockwise direction (when viewed from the right side of the rifle) by a spring  72  to fall upon a firing pin  29  (see  FIG. 11 ) when released by a pull of the trigger  74 . Trigger  74  is mounted substantially within receiver  12  and pivots on a pin  76 . Trigger  74  is biased in a counterclockwise direction by a spring  78 . 
       FIG. 9  shows body  62  in detail as comprising a first surface  80  that is engageable with the bolt carrier (see  FIG. 11 ) when the body  62  is in the first position, and a second surface  82  that engages hammer  68  when the body  62  is in the second position (see  FIG. 13 ). The hammer engaging surface  82  is positioned on a boss  84  that projects transversely from the body  62 . A tab  86  is attached to body  62  in spaced relation to pin  64 . Analogous to tab  50  in  FIG. 5A , the tab  86  extends to the outside of the receiver  12  to permit manual actuation of body  62  between the first and second positions. Pin  64  is mounted on the outside of receiver  12  on lugs  52 . 
       FIG. 10  shows hammer  68  in detail. In mechanism example  60 , hammer  68  includes a notch  90 . When trigger  74  is pulled and pivots about its pin  76 , the hammer  68  is released and pivots about its pivot pin  70  under the force of its biasing spring  72 . As described below, hammer  68  will engage the second surface  82  on boss  84  of body  62  when the body is in the second position, i.e., the position where the first surface  80  of body  62  is not engageable with the bolt carrier  14 . 
     Operation of the rifle  10  and mechanism  60  are now described with reference to  FIGS. 11-13 .  FIG. 11  shows a portion of the receiver  12 , barrel  16 , and chamber  18  of rifle  10  with the bolt carrier  14  held in the open position by body  62 . Body  62  is in the first position wherein the first surface  80  engages and blocks motion of the bolt carrier toward chamber  18  under the biasing force of a return spring (not shown). Rifle  10  may be fired by first manually depressing tab  86 . This pivots body  62  about an axis  92  coaxial with pin  64 , moving the body  62  into the second position (see  FIG. 13 ) and thereby releasing the bolt carrier  14 , the first surface  80  no longer engaging the bolt carrier. Biased by its return spring (not shown), bolt carrier  14  moves toward chamber  18 , strips a round from magazine  22  received in magazine well  20 , and chambers the round in chamber  18 . 
     If tab  86  is then released, the body  62  pivots out of the second position under the force of biasing spring  66  and into engagement with the bottom of the bolt carrier  14  and near the first position as shown in  FIG. 12 . When body  62  is in this position (i.e., not in the second position) the boss  84  is aligned with the notch  90  in hammer  68 . Hammer  68  thus will not engage the second surface  82  when the trigger  74  is pulled, and pulling trigger will discharge the rifle. As the round is discharged, the bolt carrier  14  is driven back away from the chamber against its return spring (for example by recoil, blow-back or gas operation). The spent cartridge is extracted from the chamber and ejected. The bolt carrier passes over the body  62  as it travels away from the chamber  18 . Body  62  then pivots back to the first position under the force of its biasing spring  66  when the bolt carrier  14  clears the body. When the bolt carrier reaches the end of its travel, its return spring forces it forward toward the chamber  18 . However, its motion is arrested by the body  62 , the first surface  80  again engaging the bolt carrier  14  ( FIG. 11 ). The next round may be loaded by depressing the tab  86  to release the bolt carrier and chamber another round. The round may be fired by releasing the tab  86  and pulling the trigger  74 . 
     However, if the tab  86  is not released, but is continuously depressed after the bolt carrier is released, then the body  62  is maintained in the second position. With body  62  in the second position, as shown in  FIG. 13 , boss  84  is out of alignment with notch  90  of hammer  68 . When the trigger  74  is pulled, engagement between the hammer  68  and the second surface  82  on boss  84  prevents the hammer from falling on the firing pin  29 , thereby preventing discharge of the rifle. As shown in  FIG. 12 , release of the tab  86  permits the body  62  to pivot back toward the first position (i.e., out of the second position), moving boss  84  into alignment with notch  90  of hammer  68  and permitting the hammer to fall onto the firing pin  29  and discharge the rifle when trigger  74  pulled.