Patent Publication Number: US-7707760-B2

Title: Safety apparatus for weapons

Description:
RELATED APPLICATION 
   This patent is a continuation of International Patent Application Serial No. PCT/EP2006/011418, filed Nov. 28, 2006, which claims priority to German Patent Application 10 2005 057 130.1, filed on Nov. 30, 2005, both of which are hereby incorporated herein by reference in their entireties. 

   FIELD OF THE DISCLOSURE 
   The application relates generally to safety apparatuses for weapons, and specifically, to safety apparatus for weapons with interchangeable barrels. 
   BACKGROUND 
   Weapons are often equipped with interchangeable barrels. After a cartridge is ignited, a projectile is pushed through a passageway of the barrel creating vibration and stress that is absorbed through oscillations of the barrel. During continuous firing or rapid projectile releases, overheating of the barrel may result due to friction energy from the projectile in the barrel and gas pressure from igniting the propellant in the cartridges. In some instances, overheating of the barrel can result in a gas pressure inside of an ignited cartridge shell to increase to a level that causes the cartridge shell to break apart and, thus, block a cartridge chamber. Additionally, continuous firing, especially of high caliber ammunition such as machine guns and grenade launchers, increases the temperature of the barrel causing the barrel to expand and, thus, reducing shot precision and hit rate. 
   Known weapons have been provided with interchangeable barrels that are able to be interchanged regardless of the number of shots fired. Typically, the interchangeable barrel is bolted with a holding bracket or coupled to the holding bracket in another manner. The rear end of the interchangeable barrel is provided with a cartridge chamber where cartridges are loaded and ignited (e.g., fired). Igniting rounds in the cartridge chamber produces high gas pressure and, therefore, the walls of the cartridge chamber are typically stronger than that of the interchangeable barrel. If the cartridge is in the correct position in the cartridge chamber while the cartridge is ignited, the cartridge shell can seal the gas pressure in the barrel. Typically, the cartridge chamber forms a negative imprint on the cartridge shell that is typically made of a relatively soft and flexible copper-brass-alloy. After the cartridge is ignited, the cartridge shell normally conforms exactly to the walls of the cartridge chamber and, thus, seals the gas pressure produced within the interchangeable barrel. 
   Alternatively, if the interchangeable barrel is not correctly mounted, bolted and/or locked on the holding bracket due to, for example, operating errors, the cartridge shell will not correctly fit into the cartridge chamber and, therefore, the cartridge shell will not seal the gas pressure in the interchangeable barrel. This may cause the firing pin not to reach a cap of the cartridge preventing the release of the projectile and causing a jam. Alternatively, if the firing pin reaches the cap and an ignition takes place, the non-sealed gas pressure can cause the barrel to explode causing serious injury to the operator. 
   There is a large selection of known safety mechanisms related to trigger mechanisms, locking systems, etc. that have the intention of preventing an automatic or unintentional ignition of a cartridge. However, in weapons with interchangeable barrels, these known safety mechanisms do not prevent shots from being fired if interchangeable barrel is not correctly mounted, bolted and/or locked and, thus, they create a considerable danger for the weapon operator and/or other bystanders. 
   A known example, DE 35 41 312 C2, describes a locking mechanism that interacts with a firing pin locking device so that a firing pin is blocked and is unable to reach the cartridge head if the barrel is released. Additionally, DE 35 41 312 C2 describes a release clamp to lock and release the barrel of portable automatic firearms that blocks a weapon lock if the barrel is released. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1   a  illustrates a perspective view of an example weapon including an example interchangeable barrel, an example barrel locking device, and an example safety mechanism. 
       FIG. 1   b  illustrates a perspective view of the weapon of  FIG. 1   a  with an example feeder cover in an open position. 
       FIG. 1   c  illustrates a perspective view of the weapon of  FIG. 1   a  with the interchangeable barrel partially extracted and the feeder cover in a half-open position. 
       FIG. 2  illustrates a partial perspective top view of the weapon of  FIG. 1   a.    
       FIG. 3   a  illustrates a partial side view of the weapon of  FIG. 1   a  including an example locking mechanism with the feeder cover in the open position. 
       FIG. 3   b  illustrates a side view of the weapon of  FIG. 1   a  including the example locking mechanism of  FIG. 3   a  with the feeder cover engaging an example barrel retaining element. 
   

   DETAILED DESCRIPTION 
   Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity. Further, throughout this description, position designations such as “above,” “below,” “top,” “forward,” “rear,” “left,” “right,” etc. are referenced to a firearm held in a normal firing position (i.e., wherein the “shooting direction” is pointed away from the marksman in a generally horizontal direction) and from the point of view of the marksman. Furthermore, the normal firing position of the weapon is always assumed, i.e., the position in which the barrel runs along a horizontal axis. 
   The disclosure and the illustrated examples relate to a weapon  1  comprising an interchangeable barrel  4 , a barrel locking device  22  that can couple the interchangeable barrel  4  to the weapon  1 , and a safety mechanism that can be placed in a locked position or an unlocked position. When the safety mechanism is in the unlocked position, the safety mechanism prevents the weapon  1  from firing a cartridge (e.g., igniting a cartridge, releasing a shot, etc.). Alternatively, when the safety mechanism is in the locked position, the safety mechanism allows the weapon  1  to fire a cartridge. In some examples, the safety mechanism includes the barrel locking device  22 . The barrel locking device  22  prevents the safety mechanism from entering the locked position if the interchangeable barrel  4  is not coupled to the weapon  1  via the barrel locking device  22 . 
   Although the disclosure and the illustrated examples relate to a grenade launcher, persons of ordinary skill in the art will readily appreciate that the disclosed apparatus can be used in any suitable firearm or weapon that has an interchangeable barrel such as, for example, rifles, machine guns, pistols, assault weapons, cannons, naval guns, stationary guns mounted on a weapon carrier, weapons that fire small or large diameter bullets etc. 
     FIG. 1   a  illustrates a perspective view of the example weapon  1  (e.g., grenade launcher) including the example interchangeable barrel  4 , the example barrel locking device  22 , and the example safety mechanism. In some examples, the weapon  1  includes a holding bracket  2  that receives the interchangeable barrel, a cartridge feeding device  5 , a feeder cover  6 , and a housing  8 . In the remainder of the disclosure, components of the weapon  1  such as, for example, a locking system, a trigger mechanism, etc. are not further described because they are known in the art. For a description of the components of a grenade launcher assembly see, for example, German patent DE 43 45 228 A1. 
   In this example, the holding bracket  2  is coupled to the front end of the housing  8  and guides the interchangeable barrel  4  along substantially the center of a cartridge chamber (not shown). The interchangeable barrel  4  may be inserted (e.g., received) into the holding bracket  2 . 
   In the illustrated example, the feeder cover  6  is comprised of a flat container with an opening (not shown) towards the bottom that includes a belt infeed (not shown) on an exterior face. The belt infeed is provided with two guiding channels  20  that are opposite one another and are separated by a distance that, in some examples, corresponds to a diameter of a cartridge (not shown) near a cartridge head (not shown) or a cartridge bottom (not shown) and the distance may additionally include, in some examples, a wall thickness of a belt that operatively couples the individual cartridges together. The feeder cover  6  is rotatable about an axis between an open position and a closed position and at least a portion of the feeder cover  6  is substantially torque proof. The safety mechanism also comprises preventing the cartridge from being supplied to the cartridge chamber if the feeder cover  6  is in the open position and, thus, prevents the cartridge from being fired. Additionally, the safety mechanism may prevent a cartridge from being fired that is in the cartridge chamber by blocking the locking system and/or the trigger mechanism from coming into contact with the cartridge. 
   In this example, the feeder cover  6  is provided with a plurality of first eyelets  10  and the holding bracket  2  is provided with a plurality of corresponding second eyelets  16 . The plurality of first eyelets  10  and the plurality of second eyelets  16  have through holes that have substantially the same diameter corresponding to a diameter of a locking member  12 . The feeder cover  6  and the holding bracket  2  may be coupled together in any suitable manner such as, for example, guiding the locking member  12  through the plurality of first eyelets  10  and the plurality of second eyelets  16 . The locking member  12  may be positioned substantially lateral relative to the interchangeable barrel  4 . The feeder cover  6  is rotatable around the locking member  12 . In the illustrated example of  FIG. 1   a , the feeder cover  6  is in the closed position that allows for the cartridges to be supplied laterally via the cartridge feeding device  5  crosswise to the interchangeable barrel  4  and over a lock (not shown) of the cartridge chamber. In some examples, after the cartridge is fired, the empty shell casing (not shown) may be ejected via an ejection window (not shown) positioned opposite of the belt infeed. 
   In the illustrated examples, the locking member  12  is provided with a locking spring  46  that protrudes from the locking member  12  and is positioned at an end  44  of the locking member  12 . The locking spring  46  may secure the position of the locking member  12  relative to the plurality of first eyelets  10  and the plurality of second eyelets  16  and may prevent the locking member  12  from being unintentionally removed or dropped. To remove the locking member  12 , the locking spring  46  may be pushed by hand or with a tool into the locking member  12  so that the locking spring  46  protrudes less from the locking member  12  and, thus, the locking member  12  can be extracted through the first plurality of eyelets  10  and through the second plurality of eyelets  16 . Removing the locking member  12  from the first plurality of eyelets  10  and the second plurality of eyelets  16  allows for the feeder cover  6  to be removed to be cleaned or for any other purpose such as, for example, replacing the feeder cover  6  or for other maintenance of the weapon  1 . 
   In this example, the interchangeable barrel  4  may be coupled to the holding bracket  2  into the locked position by a barrel locking device  22  via a barrel retaining element  14 . The interchangeable barrel  4  is provided with guide rings  3  ( FIG. 1   c ) that are positioned near an end of the interchangeable barrel  4  and may at-least partially facilitate the centering of the interchangeable barrel  4  in the holding bracket  2  if the interchangeable barrel  4  is inserted into the holding bracket  2 . In the illustrated examples, a first guide ring  3  is provided with a lateral slot  7  ( FIG. 1   c ) that corresponds to a projection (not shown) inside of the holding bracket  2  that allows the interchangeable barrel  4  to be rotationally coupled to the holding bracket  2 . If the interchangeable barrel  4  is at a stop limit (not shown), the interchangeable barrel  4  can be placed in the locked position. To lock the interchangeable barrel  4  into position, the barrel retaining element  14  is inserted into a partially tubelike guide  39  ( FIG. 1   b ) to a stop limit stop (not shown). An exterior diameter of the retaining element  14  substantially corresponds to an interior diameter of the tubelike guide  39 . The guide  39  is comprised of a groove  40  that is positioned on one of the guide rings  3  on the interchangeable barrel  4  in combination with a crosswise slot  42  that is substantially parallel above the guide rings  3 . Ends of the barrel retaining element  14  may be mounted in a plurality of drill holes  15   a  and  15   b  in the holding bracket  2 . 
   In the illustrated example, the barrel locking device  22  may include a sensor element  24  (e.g., a sensor pin  24 ). A projection  34  ( FIG. 2 ) is positioned substantially parallel to the interchangeable barrel  4  and may be coupled to the interchangeable barrel  4  opposite the cartridge chamber. In some examples, the projection  34  may engage (e.g., push) the sensor element  24 . If the interchangeable barrel  4  is inserted into the holding bracket  2 , the projection  34  ( FIG. 2 ) engages the sensor element  24  and moves the sensor element  24  from a second sensor element position to a first sensor element position by, for example, overcoming a biasing force of a sensor element spring  25 . The sensor element spring  25  may be positioned parallel to the direction of the interchangeable barrel  4  in the holding bracket  2 . In the illustrated example of  FIG. 1   a , the interchangeable barrel  4  is at the stop limit and, therefore, the sensor element  24  is in the first sensor element position. 
   In this example, the sensor element  24  is provided with a recess  30  on an upper side of the sensor element  24 . In a first sensor element position, the sensor element  24  is pushed into the holding bracket  2  and the recess  30  may be substantially flush with the groove  40  of the guide  39  and, therefore, a passage for the lower area of the guide  39  is formed. The barrel retaining element  14  is insertable through the guide  39  into the locking position; however, if the sensor element  24  is not in the first sensor element position the sensor element  24  may prevent the barrel retaining element  14  from being fully inserted into the guide  39 . 
   In some examples, a locking mechanism  26  ( FIGS. 3   a  and  3   b ) interacts with the barrel locking device  22  and prevents the feeder cover  6  from closing (i.e., entering the closed position) if the interchangeable barrel  4  is not correctly positioned and/or locked (i.e. coupled) in the holding bracket  2 . The locking mechanism  26  is provided with a blocking plate  28  that may be coupled to an outside edge of the feeder cover  6  and positioned toward the interchangeable barrel  4 . Additionally, the blocking plate  28  may be positioned substantially perpendicular (i.e., vertical) relative to a bottom face of the feeder cover  6 . The barrel retaining element  14  protrudes from the guide  39  if the barrel retaining element  14  is not at the second stop limit (e.g., the locked position) and, therefore, the barrel retaining element  14  may prevent the feeder cover  6  from being in a closed position via the blocking plate  28 . If the barrel retaining element  14  is not in the locked position, as the feeder cover  6  is moving toward the closed position, the barrel retaining element  14  engages the blocking plate  28  ( FIGS. 3   a  and  3   b ) and prevents the feeder cover  6  from being in the closed position. 
   Additionally, in the feeder cover  6  closed position, if the barrel retaining element  14  is in the locked position the blocking plate  28  may prevent removal, dropping, etc. of the barrel retaining element  14  by, for example, blocking and/or engaging an end of the barrel retaining element  14 . 
   In the illustrated examples, if the barrel retaining element  14  is removed from the holding bracket  2  for any reason such as, for example, to remove the interchangeable barrel, a stop pin  36  ( FIG. 1   a - 1   c ) is provided that prevents the barrel retaining element  14  from being entirely removed from the guide  39 . The stop pin  36  may be substantially parallel to the interchangeable barrel  4  and may be positioned above and/or substantially perpendicular to the barrel retaining element  14 . Additionally, the stop pin  36  may be positioned on the side of the holding bracket  2  and may face the blocking plate  28 . The barrel retaining element  14  may be provided with a leveled impression  48  ( FIG. 1   b ) that my run in a longitudinal direction between the ends of the barrel retaining element  14 . The impression  48  and the stop pin  36  may restrict the longitudinal movement of the barrel retaining element  14  to the length of the impression  48 . In some examples, the stop pin  36  prevents the complete removal of the barrel retaining element  14  by engaging an end of the impression  48  opposite a head  50  of the barrel retaining element  14  (i.e., a stop pin limit). 
     FIG. 1   b  is an illustrated example of a perspective view of the example weapon  1  of  FIG. 1   a  with an example feeder cover  6  in the open position (e.g., rotated by 90 degrees). In the open position, the blocking plate  28  may not engage the head  50  of the barrel retaining element  14  and, thus, the barrel retaining element  14  may be removed from (e.g., disengage) the groove  40  at the stop ring.  FIG. 1   b  illustrates the barrel retaining element  14  extracted from the guide  39  to the stop pin limit, which may allow for the interchangeable barrel  4  to be exchanged. 
     FIG. 1   c  illustrates a perspective view of the example weapon  1  of  FIG. 1   a  with the example interchangeable barrel  4  partially extracted and the feeder cover  6  in a half-open position. The guide ring  3  that is positioned at an end of the interchangeable barrel  4  may be provided with the groove  40  that forms a bottom section of the guide  39  for the barrel retaining element  14 . Upon removal of the interchangeable barrel  4 , the projection  34  ( FIG. 2 ) of the interchangeable barrel  4  no longer engages the sensor element  24  and, therefore, the biasing force of the sensor element spring  25  returns the sensor element  24  to the second sensor element position. In the second sensor element position, the sensor element  24  may be, for example, flush with a face of the holding bracket  2 , extend (e.g., protrude) out from the face of the holding bracket, etc. Additionally, in the second sensor element position, the recess  30  in the sensor pin  24  is positioned across the guide  39  and, therefore, prevents the barrel retaining element  14  from being completely inserted into the guide  39 . Additionally, if the barrel retaining element  14  can not be fully inserted into the guide  39 , the feeder cover  6  is prevented from being in the closed position because the barrel retaining element  14  blocks the path of the blocking plate  28 . 
   The example of  FIG. 2  illustrates a partial perspective top view of the example weapon  1  of  FIG. 1   a .  FIG. 2  illustrates how the projection  34  that is coupled to the interchangeable barrel  4  interacts with the sensor pin  24  and how the projection  34  may move (e.g., insert) the sensor pin  24  into the holding bracket  2 . After the sensor pin  24  is inserted into the holding bracket  2  (i.e., the first sensor position) the recess  30  no longer blocks the guide  39  and, therefore, the barrel retaining element  14  may be completely inserted into the guide  39  (i.e., the locking position). 
   The example of  FIG. 3   a  illustrates a side view of the example weapon  1  of  FIG. 1   a  including an example locking mechanism  26  with the feeder cover  6  in the open position (e.g., the feeder cover  6  rotated upward about 90 degrees).  FIG. 3   b  illustrates a side view of the example weapon  1  of  FIG. 1   a  including the example locking mechanism  26  of  FIG. 3   a  with the feeder cover  6  engaging the blocking plate  28 . In the illustrated example of  FIG. 3   b , the barrel retaining element  14  is not completely inserted into the guide  39  and, thus, not in the locked position. 
   The disclosed apparatuses and methods can be used in any suitable firearm(s) or weapon(s) that has an interchangeable barrel such as, for example, stationary guns mounted on a weapon carrier, weapons that fire small or large diameter bullets, grenade launchers, rifles, machine guns, pistols, assault weapons, machine guns for light armored vehicles, etc. 
   The interchangeable barrel  4  may be locked to the weapon  1  in any suitable manner such as, for example, a bayonet lock, a screw thread, or an indexing lock. As described above, the barrel locking device  22  may be provided with a barrel retaining element  14  that is any suitable barrel retaining device such as, for example, a bolt, a pin, a screw. The barrel retaining element  14  may be placed in the unlocked position or the locked position. In the locked position, the barrel retaining element  14  at-least partially locks the interchangeable barrel  4  in place. In some examples, a bolt is used as the barrel retaining element  14  and may be inserted and removed quickly in the guide  39  to exchange the interchangeable barrel  4 . Alternatively, if a pin or a screw is used as the barrel retaining element  14 , a tool may be required to remove the barrel retaining element  14  such as, for example, a screw driver. Additionally, in the illustrated examples, the locking mechanism  26  includes the blocking plate  28  that may be coupled to the feeder cover  6  that is at least partially (e.g., rigid). The blocking plate  28  engages the barrel retaining element  14  preventing the feeder cover  6  from being in the closed position if the barrel retaining element  14  is not in the locked position (i.e., completely inserted into the guide  39 ). Alternatively, if the barrel retaining element  14  is in the locked position, the feeder cover  6  may be placed in the closed position. 
   As stated above, the locking device  22  may be comprised of the holding bracket  2  and may be provided with the sensor element  24  that interacts with interchangeable barrel  4  and/or the barrel retaining element  14  that prevents the barrel retaining element  14  from being placed in the locked position if the interchangeable barrel  4  has not been accepted and/or locked in the holding bracket  2 . The locking device  22  may ensure that the interchangeable barrel  4  is in the locked position (e.g., proper position, firing position) to seal the gas pressure that is produced when a cartridge is fired. 
   As stated above, the sensor element  24  may be biased by the sensor element spring  25  and positioned between the first sensor element position and the second sensor element position. The sensor element  24  may interact with the projection  34  that may be coupled to the interchangeable barrel  4 . The interchangeable barrel  4  is inserted into the holding bracket  2  and the projection  34  engages the sensor element  24 , overcomes the sensor element spring  25  and moves the sensor element  24  to the first sensor element position. The sensor element  24  may be provided with the recess  30  that allows the barrel retaining element  14  to be in the locked position if sensor element  24  is in the first sensor element position. The barrel retaining element  14  may be completely inserted into the guide of the holding bracket (e.g., the locked position) if the interchangeable barrel  4  has been accepted and/or locked into the holding bracket  2 . 
   As discussed above, in the feeder cover  6  closed position, the feeder cover  6  or an element that is coupled to the feeder cover  6  (e.g., the blocking plate  28 ) prevents the removal of the barrel retaining element  14  by preventing the barrel retaining element  14  from being in a position other than the locked position. Being able to prevent the removal of the barrel retaining element  14  may provide additional protection against unintentional dropping, unintentional removal, etc. of the barrel retaining element  14  and/or may prevent the interchangeable barrel  4  from being unlocked. 
   As described above, the barrel retaining element  14  may be in a form substantially similar to a bolt and may move transverse to the interchangeable barrel  4  in the holding bracket  2 . The blocking plate  28  may be coupled to the feeder cover  6  and may impact an end of the barrel retaining element  14 . Additionally, the blocking plate  28  is at least partially torque proof. The blocking plate  28  may be integrally coupled to the feeder cover  6 . Specifically, the blocking plate  28  may be integrally coupled to the eyelet  10  of the feeder cover  6 . Alternatively, the blocking plate may be coupled to the feeder cover  6  in any other suitable manner such as, for example, welding, etc. 
   As discussed above, the sensor element  24  may be any suitable sensor element  24  such as, for example, a bolt, a pin, etc. that may be inserted in the holding bracket  2  substantially parallel to the interchangeable barrel  4 . The sensor element  24  may be provided with the recess  30  that the barrel retaining element  14  may be guided through or, alternatively, there may be a complete opening that the barrel retaining element  14  passes through. Alternatively, the barrel retaining element  14  may be provided with a push handle that may block the guide. 
   In the illustrated example, the interchangeable barrel  4  is provided with the groove  40  positioned at the end of the interchangeable barrel  4  that the barrel retaining element  14  may be inserted into the holding bracket  2 . 
   The stop pin  36  may prevent the barrel retaining element  14  from being completely removed from the weapon  1 . In other examples, the barrel retaining element  14  does not include the stop pin  36 . 
   Furthermore, although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.