Ballistic system and method for cutting a multi-link metal chain
RE047850 ยท 2020-02-11
Assignee
Inventors
- Darron Phillips (San Antonio, TX, US)
- Mark Ferris (San Antonio, TX, US)
- Bert Vermeulen (Cheyenne, WY, US)
Cpc classification
F41A21/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B25D9/11
PERFORMING OPERATIONS; TRANSPORTING
International classification
F41C27/20
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B25D9/11
PERFORMING OPERATIONS; TRANSPORTING
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.
Claims
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 .Iadd.along a barrel axis defined by the center of the barrel.Iaddend.; 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.]. .Iadd.nearest .Iaddend.the barrel .Iadd.axis .Iaddend.and a second adjacent link engagement feature located on a side of the second target link pin .[.facing.]. .Iadd.nearest .Iaddend.the barrel .Iadd.axis .Iaddend.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 the.]. .Iadd.a .Iaddend.plane midway between the first flat surface and the second flat surface is coplanar with .[.a barrel axis defined by the center of the barrel.]. .Iadd.the barrel axis.Iaddend.; 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.]. .Iadd.nearest the barrel axis.Iaddend., 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: .[.the.]. .Iadd.a .Iaddend.gap between the first pin and the second pin facilitates alignment of a target link of the metal chain, wherein: the gap .[.comprises.]. .Iadd.is at least partially defined by .Iaddend.a first surface located on the first pin and a second surface located on the second pin; and .[.the.]. .Iadd.a .Iaddend.mid-plane .[.of.]. .Iadd.between .Iaddend.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.]. .Iadd.two of the three rigid pins.Iaddend.; placing a second link over .[.a third pin.]. .Iadd.the third of the three rigid pins.Iaddend., wherein the second link .[.comprises a link.]. .Iadd.is .Iaddend.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.
.Iadd.21. The system of claim 1 wherein the firearm attachment feature detachably attaches to the firearm. .Iaddend.
.Iadd.22. The system of claim 1 wherein the firearm attachment feature permanently attaches to the firearm. .Iaddend.
.Iadd.23. The system of claim 5 wherein the firearm attachment feature detachably attaches to the firearm. .Iaddend.
.Iadd.24. The system of claim 5 wherein the firearm attachment feature permanently attaches to the firearm. .Iaddend.
.Iadd.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. .Iaddend.
.Iadd.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. .Iaddend.
.Iadd.27. The chain holder claim 26 wherein the first side detachably attaches to the firearm. .Iaddend.
.Iadd.28. The chain holder of claim 26 wherein the first side permanently attaches to the firearm. .Iaddend.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present disclosure is described in conjunction with the appended figures in which:
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(13) It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood that the invention is not necessarily limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION
(14) The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It should be understood that various changes could be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.
(15) Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, shapes and geometries may be shown generically and details may be left out in order not to obscure the embodiments in unnecessary detail.
(16) Embodiments of the present invention are based on using the kinetic energy and/or the momentum of a projectile to sever and open a space in a target link of a metal chain. The kinetic energy of a projectile is given as mv.sup.2 where m is the mass and v is the velocity. The momentum of the projectile is given as .[.my.]. .Iadd.mv .Iaddend.(mass times velocity). Both kinetic energy and momentum can be useful in severing and opening the space in the target link of a chain if the projectile can be accurately aimed at the right part of the target link. In an inelastic collision, some or all of the energy of a projectile is converted to heat, which can be used to soften, melt, or vaporize the material in a portion of the target link. The momentum can be used to open the softened part of the target link. Embodiments of the present invention can use kinetic energy and/or momentum from a projectile to open a gap in a target link of a chain so that the chain can be taken apart. Embodiments of the present invention can align and/or hold the target link in the chain accurately and securely enough to allow the kinetic energy and/or momentum of a projectile to do the job.
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(18) TABLE-US-00001 Typical Approx- muzzle Approx- imate Diameter velocity imate energy of Gage & of bullet (ft/sec)/ bullet mass bullet Type inch/mm (m/sec) grains/grams (Joules) 22 rifle 0.22 in 1080 ft/sec 40 grains 140 Joules 5.45 mm 330 m/sec 2.6 grams 223 rifle 0.223 in 2600 ft/sec 55 grains 1100 Joules (AR15) 5.56 mm 790 m/s 3.6 grams 308 rifle 0.308 in 2580 ft/sec 175 grains 3500 Joules 7.62 mm 790 m/sec 11 grams 38 caliber 0.38 in 1200 ft/sec 124 grains 540 Joules pistol 9.00 mm 360 m/sec 8 grams (9 19 mm) 45 caliber 0.45 in/ 830 ft/sec 230 grains 480 Joules pistol 250 m/sec 15 grams 50 caliber 0.50 in 3000 ft/sec 700 grains 19,000 Joules (BMG) 12.7 mm 915 m/sec 45 grams
(19) The firearm 101 of
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(22) TABLE-US-00002 T (inches) L (inches) W (inches) 3/16 (0.187) 0.95 0.40 (0.250) 1.00 0.50 5/16 (0.312) 1.10 0.50 (0.375) 1.23 0.62 1/2 (0.500) 1.50 0.81 (0.625) 1.87 1.00 3/4 (0.750) 2.12 1.12 (0.875) 2.50 1.37 T (mm) L (mm) W (mm) 5.5 24 7.7 7.0 31 9.8 8.0 32 11.2 10.0 34 14 13.0 45 18 16.0 55 20 20.0 69 25
(23) Using the dimensions above, the density of steel (8 grams per cubic centimeter), and the energy required to melt steel (about 30 Joules/gram), one can determine if a bullet has the kinetic energy to melt enough steel in the link to cut the chain. Extensive testing showed that about 10% of the ballistic energy from an optimally aimed bullet is available for melting the steel. The remaining energy melts the bullet and is lost in other ways. Thus, one needs about 10 the calculated energy. Below is a summary of the ballistic energy needed to cut typical chains assuming that a volume of the chain equivalent to the cross sectional area of the link multiplied by the thickness of the link must be melted to create a gap in the target link.
(24) TABLE-US-00003 T (inches) Energy to melt steel 10 energy to melt 3/16 (0.19) 20 Joules 200 Joules 1/4 (0.25) 48 Joules 480 Joules 5/16 (0.31) 94 Joules 940 Joules (0.38) 160 Joules 1,600 Joules (0.50) 390 Joules 3,900 Joules (0.62) 750 Joules 7,500 Joules (0.75) 1,300 Joules 13,000 Joules 7/8 (0.88) 2,100 Joules 21,000 Joules
(25) Using the above information and the ballistic energy that was calculated for various gages and types of bullets, the following table shows which firearms can cut what sizes of chains if the bullet is accurately aimed at an optimal location on a target link of the chain. Note that it is desirable to cut the chain even when the energy available has been labeled as Marginal, by ensuring that the bullets are aimed accurately and consistently at the optimal location and in the optimal orientation to the target link.
(26) TABLE-US-00004 Link Does this firearm have enough energy to cut this chain? Thick- 22 45 38 308 ness T Rifle Pistol Pistol AR 15 Rifle BMG (inches) (140 J) (480 J) (540 J) (1,100 J) (3,500 J) (19,000 J) 3/16 Mar- Yes Yes Yes Yes Yes ginal No Mar- Mar- Yes Yes Yes ginal ginal 5/16 No No No Mar- Yes Yes ginal No No No Mar- Yes Yes ginal No No No No Mar- Yes ginal No No No No No Yes No No No No No Yes No No No No No Mar- ginal
(27) Having described the physics involved in ballistic heating and deformation of the link of a chain, the next step is to identify the optimal location and direction of impact for a bullet onto a stadium-shaped link of a chain. First it should be noted that the bullet should be fired in a direction that is coplanar with the central stadium plane of the target link so that the bullet hits the target link at the center of the circular cross-section of the stadium-shaped ring. Having defined one of the dimensions,
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(32) With reference to the previous figures that show the chain holder 102, another benefit of the chain holder design should be pointed out. The firearm can be used as a normal firearm with the chain holder 102 attached at all times. The chain holder provides no obstruction to any projectiles that might be fired.
(33) A number of variations and modifications of the disclosed embodiments can also be used. The principles described here can also be used for in applications other than chain cutting. While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure.