Ballistic system and method for cutting a multi-link metal chain

Abstract

A system and method for ballistically cutting a multi-link metal chain comprises a chain alignment module that comprises three pins and attaches to the barrel of a firearm. A first pin and a second pin of the module fit on opposite sides of a target link of the chain. A third pin of the alignment module goes through a link adjacent to the target link of the chain. The three pins align the target link so that a bullet exiting the barrel of a firearm impacts a semicircular region of the target link to cause the target link to open.

We claim: 
     
       1. A system for ballistically opening a target link of a multi-link metal chain, the system comprising:
 a firearm attachment feature wherein:
 the firearm attachment feature detachably attaches to a firearm to align the system with the path of a bullet exiting a barrel of the firearm along a barrel axis defined by the center of the barrel; and 
 
 a chain alignment module comprising:
 a first target link pin configured to sit on one side of the target link; 
 a second target link pin configured to sit on the other side of the target link; 
 a first adjacent link engagement feature located on a side of the first target link pin facing nearest the barrel axis and a second adjacent link engagement feature located on a side of the second target link pin facing nearest the barrel axis wherein:
 the first adjacent link engagement feature comprises a first adjacent link engagement flat region; 
 the second adjacent link engagement feature comprises a second adjacent link engagement flat region; 
 the first flat region is coplanar with the second flat region; and 
 the first flat region and the second flat region are configured for engaging with an adjacent link wherein the adjacent link is a link on the multi-link metal chain located adjacent to the target link and rotated 90 degrees from the target link; 
 
 a slot between the first target link pin and the second target link pin wherein:
 the slot comprises a first target link sidewall located on a side of the first target link pin and a second target link sidewall located on a side of the second target link pin; 
 the first sidewall comprises a first flat surface; 
 the second sidewall comprises a second flat surface; 
 the first flat surface is parallel to the second flat surface; 
 the midplane defined by thea plane midway between the first flat surface and the second flat surface is coplanar with a barrel axis defined by the center of the barrelthe barrel axis; and 
 the slot is configured for placement of the target link between the first flat surface and the second flat surface; and 
 
 an adjacent link pin configured to go through a central open region of the adjacent link, wherein:
 the adjacent link pin comprises a target link engagement surface located on a side of the adjacent link pin facing an end of the barrel nearest the barrel axis, wherein the target link engagement surface is configured as a stop for a semicircular end of the target link; 
 the adjacent link pin further comprises a first adjacent link pin side and a second adjacent link pin side; 
 the first adjacent link pin side and the second adjacent link pin side are on opposite sides of the adjacent link pin; 
 the first adjacent link pin side is parallel to the second adjacent link pin side; 
 the first adjacent link pin side and the second adjacent link pin side are parallel to the first flat surface and the second flat surface; and 
 the first adjacent link pin side and the second adjacent link pin side are configured for passing through the central open region; 
 
 
 whereby the first target link pin, the second target link pin, and the adjacent link pin are shaped and positioned relative to the firearm attachment feature so the path of the bullet impacts a central plane of the semicircular end of the target link. 
 
     
     
       2. The system of  claim 1  wherein:
 the system is configured to attach to a barrel of a firearm that uses a 0.223-inch diameter bullet; and 
 the system further comprises the multi-link chain, wherein:
 the target link and the adjacent link comprise a maximum cross-sectional diameter of 0.375 inches; and 
 the target link and the adjacent link comprise a minimum cross-sectional diameter of 0.188 inches. 
 
 
     
     
       3. The system of  claim 1  wherein the system attaches to a silencer that attaches to the barrel of the firearm. 
     
     
       4. The system of  claim 1  wherein the system attaches directly to the barrel of the firearm and the firearm attachment feature comprises a threaded connection. 
     
     
       5. A system for ballistically cutting a multi-link metal chain, the system comprising:
 a firearm attachment feature wherein:
 the firearm attachment feature detachably attaches to the barrel of a firearm to align the system with the path of a bullet exiting the firearm; and 
 
 a chain alignment module comprising a first pin, a second pin, and a third pin, wherein:
 thea gap between the first pin and the second pin facilitates alignment of a target link of the metal chain, wherein:
 the gap comprises is at least partially defined by a first surface located on the first pin and a second surface located on the second pin; and   thea mid-plane ofbetween the first surface and the second surface is coplanar with the path of the bullet;   
 the third pin fits through the center of a link adjacent to the target link; 
 the third pin comprises a target link engagement surface for positioning a semicircular region of the target link with the path of the bullet; 
 the first pin comprises a first feature for engaging the link adjacent to the target link; 
 the second pin comprises a second feature for engaging the link adjacent to the target link; and 
 the first feature and the second feature are parallel. 
 
 
     
     
       6. The system of  claim 5  wherein:
 the system is configured to attach to a barrel of a firearm that uses a 0.223-inch diameter bullet; and 
 the system further comprises the multi-link chain, wherein:
 the target link and the adjacent link comprise a maximum cross-sectional diameter of 0.375 inches; and 
 the target link and the adjacent link comprise a minimum cross-sectional diameter of 0.188 inches. 
 
 
     
     
       7. The system of  claim 5  wherein the system attaches to a silencer that attaches to the barrel of the firearm. 
     
     
       8. The system of  claim 5  wherein the system attaches directly to the barrel of the firearm and the firearm attachment feature comprises a threaded connection. 
     
     
       9. The system of  claim 5  wherein the chain alignment module is configured to fit the target link of a chain that has a cross sectional diameter greater than or equal to a value selected from the group of 0.187 inches, 0.250 inches, and 0.375 inches. 
     
     
       10. The system of  claim 5  wherein the chain alignment module is configured to fit the target link of a chain that has a cross sectional diameter less than or equal to a value selected from the group of 0.187 inches, 0.250 inches, and 0.375 inches. 
     
     
       11. The system of  claim 5  wherein the chain alignment module is configured to align and fit all multi-link chains that have a stadium-shaped target link further comprising:
 a circular cross section with a diameter in the range of 0.187 inches to 0.375 inches; 
 an inside length ranging from 0.95 inches to 1.23 inches; and 
 an inside width ranging from 0.4 inches to 0.62 inches; and 
 
       a stadium-shaped adjacent link connected to the target link and rotated 90 degrees from the target link comprising:
 a circular cross sectional with a diameter in the range of 0.187 and 0.375 inches; 
 an inside length ranging from 0.95 inches to 1.23 inches; and 
 an inside width ranging from 0.4 inches to 0.62 inches. 
 
     
     
       12. The system of  claim 5  wherein the firearm uses a 0.223-inch bullet. 
     
     
       13. The system of  claim 5  wherein:
 the firearm uses a 0.308-inch bullet; and 
 the system further comprises the multi-link chain, wherein:
 the target link and the adjacent link comprise a maximum cross-sectional diameter of 0.5 inches; and 
 the target link and the adjacent link comprise a minimum cross-sectional diameter of 0.25 inches. 
 
 
     
     
       14. The system of  claim 5  wherein the path of the bullet impacts the target link in the semicircular region of the target link at an angle of incidence that further causes an opening of the target link to be large enough that the adjacent link can be detached from the target link. 
     
     
       15. The system of  claim 5  wherein:
 the first pin, the second pin, and the third pin are in a triangular configuration; 
 the first feature comprises a first flat region; 
 the second feature comprises a second flat region; 
 the first region is coplanar with the second region; 
 the first surface is parallel to the second surface; 
 the third pin comprises a first adjacent link pin side and a second adjacent link pin side; 
 the first adjacent link pin side is parallel to the second adjacent link pin side; and 
 the first adjacent link pin side and the second adjacent link pin side are parallel to the first surface and the second surface. 
 
     
     
       16. The system of  claim 5  wherein the first pin, the second pin, and the third pin are shaped and positioned relative to the firearm attachment feature so the path of the bullet impacts the target link in the semicircular region of the target link at an angle of incidence that is outboard from perpendicular at the point of impact. 
     
     
       17. The system of  claim 5  wherein:
 the first pin, the second pin, and the third pin have angled surfaces; and 
 the target link engagement surface is a flat angled surface located on the side of the third pin facing the path of the bullet. 
 
     
     
       18. A method for ballistic cutting of a multi-link metal chain, the method comprising the steps of:
 establishing a fixture comprising three rigid pins; 
 aligning the fixture with the path of a bullet exiting a firearm proximate to the point where the bullet exits the barrel of the firearm; 
 placing a target link of the multi-link metal chain between a first pin and a second pin two of the three rigid pins; 
 placing a second link over a third pin the third of the three rigid pins, wherein the second link comprises a link is adjacent to the target link; and 
 wherein placing the target link and placing the second link further comprise placing the target link in a location so that the path of the bullet impacts the target link in a semicircular region of the target link at an angle of incidence that causes the target link to open. 
 
     
     
       19. The method of  claim 18  wherein:
 the method is used to cut a steel multi-link metal chain; and 
 the chain comprises a plurality of stadium-shaped interconnected steel links that are oriented at 90 degree angles from each other. 
 
     
     
       20. The method of  claim 18  wherein the method further comprises the step of removing the target link from the second link. 
     
     
       21. The system of claim 1 wherein the firearm attachment feature detachably attaches to the firearm.  
     
     
       22. The system of claim 1 wherein the firearm attachment feature permanently attaches to the firearm.  
     
     
       23. The system of claim 5 wherein the firearm attachment feature detachably attaches to the firearm.  
     
     
       24. The system of claim 5 wherein the firearm attachment feature permanently attaches to the firearm.  
     
     
       25. A chain holder for ballistically opening a target link of a multi-link chain, said chain holder being attachable to a firearm having a barrel and comprising:
 a first target link pin having a first side with a first flat region for engaging a link connected to the target link and a second side with a first flat surface at least partially defining a slot;   a second target link pin having a first side with a second flat region for engaging a link connected to the target link and a second side with a second flat surface at least partially defining the slot, said second flat region being coplanar with the first flat region, and said second flat surface being parallel with the first flat surface;   a midplane halfway between the first flat surface and the second flat surface, said midplane being coplanar with a barrel axis defined by the center of the barrel when the chain holder is attached to the firearm;   an adjacent link pin with a target link engagement surface facing the barrel axis when the chain holder is attached to the firearm, a first adjacent link pin side and a second adjacent link pin side opposite the first adjacent link pin side, said first adjacent link pin side and a said second adjacent link pin side being parallel to the midplane; and   
       wherein the target link has a semicircular end with a central plane in the barrel axis when the chain holder is attached to the firearm and the target link is inserted into the slot.  
     
     
       26. A chain holder for ballistically opening a target link of a multi-link chain, said chain holder being attachable to a firearm having a barrel and comprising:
 a first side attachable to a firearm;   a second side opposite the first side;   an aperture extending between the first side and the second side, said aperture being axially aligned with a barrel axis defined by the center of the barrel when the chain holder is attached to the firearm;   a first pin extending from the second side, said first pin having a first sidewall with a first flat surface;   a second pin extending from the second side, said second pin having a second sidewall with a second flat surface substantially parallel to the first flat surface;   a gap between the first pin and the second pin, said gap being configured to receive the target link and having a midplane parallel to the first and second flat surfaces, said midplane being coplanar with the barrel axis when the chain holder is attached to the firearm;   a third pin extending from the second side, said third pin having a target link engagement surface facing the barrel axis when the chain holder is attached to the firearm, and said third pin being configured to at least partially fit through a central open region of a link adjacent to the target link; and   
       wherein the first pin comprises a first feature for engaging the link adjacent to the target link, the second pin comprises a second feature for engaging the link adjacent to the target link, and the first feature and the second feature are coplanar.  
     
     
       27. The chain holder claim 26 wherein the first side detachably attaches to the firearm.  
     
     
       28. The chain holder of claim 26 wherein the first side permanently attaches to the firearm.