Electromagnetic Gun With Parallel Wall Conductor Assembles

Abstract

Narrow cavity rail guns with: a power rail proximal each edge, a wall conductor assembly in each cavity wall there between with barrel bus at one rail and extending therefrom to distal contact means at the cavity, an array of parallel, spaced, cavity orthogonal wall conductors. Armatures for use therein have: a propulsion bus orthogonal the cavity axis with continuity the barrel buses proximal power rail at one end and the propulsion bus-aft shunt circuit means the other, and at the second power rail, a forward current shunt with continuity said contact means and said power rail, and an aft current shunt with continuity said contact means and propulsion bus-aft shunt circuit means. Armature shunts via the wall conductor assembles and said circuit means circulate the device's current around the armature propulsion bus during cavity traverse and its magnetic fields interact with the propulsion bus current propelling the armature.

1 . Electromagnetic propulsion devices comprising: 
 a barrel; and    a narrow cavity therein which extends the length of said barrel and having: 
 a uniform right section profile its length and  
 a breach end opening at one barrel end and  
 a muzzle end opening at the other barrel end and  
 a central axis which extends from said breach end opening to said muzzle end opening; and  
   two barrel rails which are: 
 power rails, and  
 parallel to said cavity axis and  
 located across the cavity from each other, and  
 located at, in, or proximal the narrow end walls of the barrel cavity and  
   each said power rails has: 
 continuous barrel cavity surface along its length and  
 power connection means at its breach end to outside the device for attachment to an outside power source, and  
   said power rails divide the barrel cavity walls into two barrel cavity wall segments with boundaries of: 
 the breach end boundary of the cavity, and  
 the muzzle end boundary of the cavity, and  
 the cavity surfaces of the two power rails and  
 ray extension therefrom to said breach and muzzle end boundaries; and  
   a wall conductor assembly located in each said barrel cavity wall segment and 
 one wall conductor assembly is the mirror image of the other across the barrel cavity, and  
   each wall conductor assembly is comprised of: 
 a barrel bus which is: 
 in the barrel cavity wall segment with said assembly and adjacent, parallel and in close proximity one of the power rails and proximal the barrel bus of the wall conductor assembly in the second barrel cavity wall segment, and  
 electrically isolated from said power rail and said second barrel bus and similar in length as said power rail and said second barrel bus and at similar location along the length of the barrel cavity as said power rail and second assembly's barrel bus, and  
 
 an array of wall conductors which are: 
 in the barrel cavity wall segment with said assembly and  
 proximal or at the barrel cavity surface of said segment and  
 parallel to each other, and  
 of equal length, and  
 spaced from each other, and  
 orthogonal the barrel cavity axis, and  
 
 each wall conductor of said array: 
 has at one end, physical and electrical continuity with the barrel bus and  
 extends from the barrel bus to proximity the narrow cavity wall distal the barrel bus and the barrel rail thereat, and  
 
 contact means for each wall conductor of said array that: 
 is located proximal the barrel bus distal end of the wall conductor and  
 has electrical continuity with said wall conductor and  
 has surface in the barrel cavity; and  
 
   armatures for propulsion through said barrel cavity having: 
 a central axis that is, with the armature in the barrel cavity, coincident the central axis of said cavity or very close to and parallel the cavity central axis, and  
 a muzzle end that is, with the armature in the barrel cavity, the armature end closest the cavity muzzle end, and  
 a breach end that is, with the armature in the barrel cavity, the armature end closest the cavity breach end, and  
 profiles in all right sections to said axis smaller then the barrel cavity right section profile, and  
   a propulsion bus that: 
 is oriented orthogonal the armature axis, and  
 is located midway between the armature's muzzle and breach ends and, with the armature in the barrel cavity,  
 extends across the cavity between the cavity's narrow end walls and  
 has surface at one end that has continuous electrical continuity with the cavity surface of the barrel bus proximal power rail and  
 has continuous electrical continuity at its other end with propulsion bus-aft shunt circuit means; and  
   a forward current shunt that: 
 is located between the propulsion bus and the muzzle end of the armature and,  
   with the armature in the barrel cavity, 
 is proximal the barrel bus distal power rail, and  
 has surface with continuous electrical continuity with cavity surface of the barrel bus distal power rail and  
 has surface at contact means of the first wall conductor assembly and, via said contact means, has continuous electrical continuity with forward wall conductor of said assembly and  
 has surface at contact means of the second wall conductor assembly and, via said contact means, has continuous electrical continuity with forward wall conductor of said assembly; and  
   an aft current shunt that: 
 is located between the propulsion bus and breach end of the armature and, with the armature in the barrel cavity,  
 is proximal the barrel bus distal power rail, and  
 has surface at contact means of the first wall conductor assembly and, via said contact means, has continuous electrical continuity with aft wall conductor of said assembly and  
 has surface at contact means of the second wall conductor assembly and, via said contact means, has continuous electrical continuity with aft wall conductor of said assembly and,  
 has continuous electrical continuity with propulsion bus-aft shunt circuit means; and  
   propulsion bus-aft shunt circuit means comprised of: 
 a third barrel rail that is: 
 in, at, or proximal the barrel bus distal narrow end wall of said cavity and  
 proximal the power rail thereat and  
 parallel said power rail and  
 electrically isolated from said power rail, and  
 of length similar said power rail's length, and  
 at similar location along the barrel cavity length as said power rail, and that has continuous barrel cavity surface along its length and  
 
 surface at the end of said propulsion bus that: 
 is proximal the current shunts and,  
 
 with an armature in the barrel cavity, 
 has continuous electrical continuity with the barrel cavity surface of said third barrel rail; and  
 
 surface on the aft current shunt that, 
 with an armature in the barrel cavity, 
 has continuous electrical continuity the barrel cavity surface of said third barrel rail.  
 
 
   
   
   
       2 . Electromagnetic propulsion devices as claimed in  claim 1  wherein an armature is retained in the breach end of the barrel cavity for release and propulsion in the barrel cavity towards the barrel muzzle on application of sufficient power to the power rails.  
   
   
       3 . Electromagnetic propulsion devices as claimed in  claim 2  wherein the armature is retained at the cavity breach by a fuse pin which: 
 at one end is retained at one power rail and has electrical continuity therewith, and    at its other end is retained in the second power rail and has electrical continuity therewith, and    extends through an armature channel there between and, with power supplied the power rails, provides a short circuit between said rails until vaporized and thereby freeing the armature for traverse of the barrel cavity.    
   
   
       4 . Electromagnetic propulsion devices as claimed in  claim 1  but wherein the propulsion bus-aft shunt circuit means is comprised of an electric current bus in the armature that is located proximal the current shunts therein and is between and connects the armature's aft current shunt and the propulsion bus.  
   
   
       5 . Electromagnetic propulsion devices as claimed in  claim 1  wherein said barrel and barrel cavity has a twist so that: 
 area elements in right sections to the barrel, when taken at incremental increasing distance from a barrel reference point, have like shape, area, and angle relative to each other at fixed radii about a barrel cavity axis at incremental increasing angular displacement about said axis from an axial reference plane and the angular displacement per unite axial distance is constant; and    said armatures for use in said barrel cavity have 
 therein an axis coincident said barrel cavity axis and a like twist so that area elements in right sections to said armature, when taken at incremental increasing distance from an armature reference point, have like shape, area, and angle relative to each other at fixed radii about the said armature axis at incremental increasing angular displacement about said axis from an axial reference plane and the angular displacement per unite axial distance is constant and identical to said barrel and barrel cavity constant.  
   
   
   
       6 . Electromagnetic propulsion devices as claimed in  claim 5  but wherein said propulsion bus-aft shunt circuit means is comprised an electric current bus in the armature that is proximal the current shunts therein and is located between and connects the armature's aft current shunt and the armature's propulsion bus.  
   
   
       7 . Electromagnetic propulsion devices as claimed in  claim 5  wherein an armature is mounted in the breach end of the barrel cavity for release and propulsion in the barrel cavity towards the barrel muzzle on application of sufficient power to the power rails.  
   
   
       8 . Electromagnetic propulsion devices comprising: 
 a barrel; and    a narrow cavity therein which extends the length of said barrel having: 
 a uniform right section profile its length and  
 a breach end opening at one barrel end and  
 a muzzle end opening at the other barrel end and  
 a central axis which extends from said breach end opening to said muzzle end opening; and  
   two barrel rails which are: 
 power rails, and  
 parallel to said cavity central axis and  
 located across the cavity from each other and  
 located at, in, or proximal the narrow end walls of the barrel cavity and  
   each said power rail has: 
 continuous barrel cavity surface along its length and  
 power connection means at its breach end to outside the device for attachment to an outside power source and  
   said barrel rails divide the barrel cavity walls into two barrel cavity wall segments with boundaries of: 
 the breach end boundary of the cavity, and  
 the muzzle end boundary of the cavity, and  
 the cavity surfaces of the two power rails and  
 ray extensions therefrom to said breach and muzzle end boundaries; and  
   a wall conductor assembly located in each said barrel cavity wall segment and one said assembly is the mirror image of the other across the barrel cavity, and 
 each said wall conductor assembly has:  
 a barrel bus that is: 
 adjacent, parallel, and in close proximity one of the power rails, and proximal, and parallel the barrel bus of the wall conductor assembly in the second barrel cavity wall segment which is also located at said power rail, and electrically isolated from said power rail and said barrel bus, and  
 of length similar to the lengths of said power rail and said barrel bus and  
 at similar location along the length of the barrel as said power rail, and 
 said barrel bus, and  
 
 
 an array of wall conductors that are: 
 in said barrel cavity wall segment and  
 proximal or at said barrel cavity wall segment's barrel cavity surface and  
 parallel to each other, and of equal length, and spaced from each other, and orthogonal the barrel cavity axis, and  
 
 each wall conductor of said array 
 has at one end physical and electrical continuity with the barrel bus and extends from the barrel bus to proximity the narrow cavity wall distal the barrel bus and the barrel rail thereat, and  
 
 contact means for each wall conductor of said array that: 
 is located proximal the barrel bus distal end of its wall conductor and  
 has electrical continuity with said wall conductor and  
 has surface coincident the barrel cavity surface and/or in the barrel cavity; and  
 
   armatures for propulsion from the breach end to muzzle end of said barrel cavity having: 
 a muzzle end that is, with the armature is in the barrel cavity, closest the barrel cavity muzzle end, and  
 a breach end that is, with the armature is in the barrel cavity, closest the barrel cavity breach end, and  
 a central axis that is, with the armature in the barrel cavity, coincident or very close to and parallel the barrel cavity central axis, and  
 all right section profiles to said axis smaller then the barrel cavity right section profile and a portion of right section profiles similar to the cavity profile but slightly undersized thereof, and  
   a propulsion bus that: 
 is oriented orthogonal the armature's central axis, and  
 is located midway between the armature's muzzle and breach ends, and, with the armature in the barrel cavity,  
 extends across the barrel cavity between said cavity's narrow end walls, and  
 has at one end surface with continuous electrical continuity with the cavity surface of the power rail proximal the barrel buses, and  
 has at its other end continuous electrical continuity with propulsion bus-aft shunt circuit means, and  
 maintains continuous electrical continuity between the barrel buses proximal power rail and propulsion bus-aft shunt circuit means, and,  
   with the armature in the barrel cavity and power supplied to the power rails, 
 maintains a continuous current path between the propulsion bus-aft shunt circuit means and the barrel buses proximal power rail in a direction orthogonal to: 
 the barrel cavity, and the barrel cavity axis, and  
 the armature axis and the direction of barrel cavity traverse by the armature, and  
 
 a direction parallel to the wall conductors of the 
 wall conductor assembles; and  
 
   a forward current shunt that: 
 is located between the armature's propulsion bus and the armature's muzzle end, and,  
   with the armature in the barrel cavity, 
 is proximal the barrel bus distal power rail, and  
 has surface with continuous electrical continuity with cavity surface of the barrel bus distal power rail, and  
 has surface that is at contact means of the first wall conductor assembly and, via said contact means, has continuous electrical continuity with forward wall conductor of said wall conductor assembly, and  
 has surface that is at contact means of the second wall conductor assembly and, via said contact means, has continuous electrical continuity with forward wall conductor of said wall conductor assembly, and  
 maintains continuous electrical continuity between forward wall conductor of the wall conductor assembles and the barrel bus distal power rail and  
   with the armature in the barrel cavity and power supplied to the power rails, maintains a current path between the barrel bus distal power rail and forward wall conductor of the wall conductor assembles; and    an aft current shunt that: 
 is located between the armature's propulsion bus and the armature's breach end, and,  
   with an armature in the barrel cavity, 
 is proximal barrel bus distal barrel rail, and  
 has surface at contact means of the first wall conductor assembly and, via said contact means, continuous electrical continuity with aft wall conductor of said assembly, and  
 has surface at contact means of the second wall conductor assembly and, via said contact means, continuous electrical continuity with aft wall conductor of said assembly, and  
 has continuous electrical continuity with propulsion bus-aft shunt circuit means, and  
 maintains continuous electrical continuity between aft wall conductor of the wall conductor assembles and the propulsion bus-aft shunt circuit means and,  
   with the armature in the barrel cavity and power supplied to the power rails 
 maintains a current path between said propulsion bus-aft shunt circuit 
 means and aft wall conductor of the wall conductor assembles; and  
 
   propulsion bus-aft shunt circuit means comprising: 
 a third barrel rail that has continuous barrel cavity surface its length, and 
 that is: 
 in, at or proximal the barrel bus distal narrow cavity end wall and  
 proximal the barrel bus distal power rail thereat, and  
 located parallel to said power rail, and  
 electrically isolated from said power rail, and  
 of length similar said power rails length, and  
 at similar location along the barrel cavity length as said power rail; and  
 
 
   surface on the propulsion bus that has, with an armature in the barrel cavity, continuous electrical continuity with the barrel cavity surface of said third barrel rail; and    surface on the aft current shunt that has, with an armature in the barrel cavity, continuous electrical continuity with the barrel cavity surface of the third barrel rail; and    said propulsion bus-aft shunt circuit means, with an armature in the barrel cavity, maintains continuous electrical continuity between the propulsion bus and aft current shunt of said armature, and    said propulsion bus-aft shunt circuit means, with an armature in the barrel cavity and power supplied to the power rails, maintains a current path between the propulsion bus and aft current shunt of said armature.    
   
   
       9 . Electromagnetic propulsion devices as claimed in  claim 8  wherein an armature is retained in the breach end of the barrel cavity for release and propulsion in the barrel cavity towards the barrel muzzle on application of sufficient power to the power rails.  
   
   
       10 . Electromagnetic propulsion devices as claimed in  claim 9  wherein the armature is retained at the cavity breach by a fuse pin which: 
 at one end is retained at one power rail and has electrical continuity therewith, and    at its other end is retained in the second power rail and has electrical continuity therewith, and    extends through an armature channel there between and,    with power supplied the power rails, provides a short circuit between said rails until vaporized and freeing the armature for traverse of the barrel cavity.    
   
   
       11 . Electromagnetic propulsion devices as claimed in  claim 8  but wherein said propulsion bus-aft shunt circuit means is comprised of an electric current bus in the armature that is located proximal the current shunts therein and that is between and connects the armature's aft current shunt and the armature's propulsion bus.  
   
   
       12 . Electromagnetic propulsion devices as claimed in  claim 8  wherein, said barrel and barrel cavity has a twist so that right sections to the barrel and elements therein, 
 when taken at incremental increasing distance from a barrel reference point, have like shape, area, and angle relative to each other at fixed radii about a barrel axis at incremental increasing angular displacement about said axis from an axial reference plane and the angular displacement per unite axial distance is constant; and    armatures for use in said barrel cavity have therein an axis coincident said barrel axis and 
 have a like twist so that right sections to said armature and elements therein, when taken at incremental increasing distance from an armature reference point,  
 have like shape, area, and angle relative to each other at fixed radii about the said armature axis at incremental increasing angular displacement about said axis from an axial reference plane and the angular displacement per unite axial distance is constant and identical to said barrel and barrel cavity constant.  
   
   
   
       13 . Electromagnetic propulsion devices as claimed in  claim 12  wherein the armature is retained at the cavity breach by a fuse pin which: 
 at one end is retained at one power rail and has electrical continuity therewith, and    at its other end is retained in the second power rail and has electrical continuity therewith, and    extends through an armature channel there between, and    with power supplied the power rails, provides a short circuit between said rails until vaporized and freeing the armature for traverse of the barrel cavity.    
   
   
       14 . Electromagnetic propulsion devices as claimed in  claim 12  but wherein said propulsion bus-aft shunt circuit means is comprised of an electric current bus in the armature that is located proximal the current shunts therein and is between and connects the armature's aft current shunt and the armature's propulsion bus.  
   
   
       15 . Electromagnetic propulsion devices comprising: 
 a barrel; and    a narrow cavity therein which extends the length of the barrel and having: 
 a uniform right section profile throughout its length and  
 a breach end opening at one barrel end and  
 a muzzle end opening at the other barrel end and  
 a central axis which extends from said breach end opening to said muzzle end opening; and  
   two barrel rails which are: 
 power rails, and  
 parallel to said cavity axis and  
 located across the cavity from each other and  
 located at, in, or proximal the narrow end walls of the barrel cavity and  
   each said power rail has: 
 a continuous barrel cavity surface along its length and  
 a power connection means at its breach end to outside the device for attachment to an outside power source and  
   said barrel rails divide the barrel cavity walls into two barrel cavity wall segments with boundaries of: 
 the breach end boundary of the cavity, and  
 the muzzle end boundary of the cavity, and  
 the cavity surfaces of the two power rails and  
 ray extensions therefrom to said breach and muzzle end boundaries; and  
   a wall conductor assembly located in each barrel cavity wall segment and 
 one wall conductor assembly is the mirror image of the other across the cavity, and  
   each wall conductor assembly has: 
 a barrel bus that is: 
 adjacent, parallel, and in close proximity one of the power rails, and  
 proximal and parallel the barrel bus of the second wall conductor assembly, and  
 electrically isolated from said power rail and the barrel bus of said second assembly, and  
 of length similar to said power rail's length and said second assembly's barrel bus length and  
 at similar location along the length of the barrel as said power rail and said second assembly's barrel bus, and  
 
 an array of wall conductors which are: 
 in said barrel cavity wall segment and  
 proximal or at its barrel cavity surface and  
 parallel to each other, and  
 of equal length, and  
 spaced from each other, and  
 orthogonal the barrel cavity axis, and  
 
 each wall conductor of said array 
 has at one end physical and electrical continuity with the barrel bus and 
 extends from the barrel bus to proximity the narrow cavity wall distal the barrel buses and barrel rail thereat, and  
 
 
 contact means for each wall conductor of said wall conductor array that: 
 is located proximal the barrel bus distal end of its wall conductor and  
 has electrical continuity with the distal end of its wall conductor and  
 has surface coincident the barrel cavity surface and/or in barrel cavity; and  
 
   armatures for propulsion from the breach end to muzzle end of said cavity having: 
 a muzzle end which, when the armature is in the barrel cavity, is closest to the barrel cavity muzzle end, and  
 a breach end which, when the armature is in the barrel cavity, is closest to the barrel cavity breach end and  
 a central axis which is, when the armature in the barrel cavity, coincident or very close to and parallel the cavity central axis, and  
 all right section profiles to said axis smaller then the barrel cavity right section profile and a portion of right section profiles similar to the cavity profile but slightly undersized thereof, and  
   a propulsion bus that: 
 is oriented orthogonal the armature axis, and  
 is located midway between the armature muzzle and breach ends and,  
   with the armature in the barrel cavity, 
 extends across the cavity between the cavity's narrow end walls, and  
 has at one end, surface with continuous electrical continuity with the cavity surface of the barrel bus proximal power rail, and  
 has at its other end, continuous electrical continuity with propulsion bus-aft shunt circuit means, and  
 maintains electrical continuity between said power rail and propulsion bus-aft shunt circuit means, and,  
   with the armature in the barrel cavity and power supplied to the power rails, 
 maintains a continuous current path between the propulsion bus-aft  
 shunt circuit means and said power rail in a direction orthogonal: 
 the barrel cavity, and the barrel cavity axis, and the armature axis  
 and the direction of barrel cavity traverse by the armature, and  
 
 in a direction parallel to wall conductors of the wall conductor assembles; and  
   a forward current shunt that: 
 is located between the armature's propulsion bus and the armature's muzzle end, and,  
   with the armature in the barrel cavity, 
 is proximal the barrel bus distal power rail, and  
 has surface with continuous electrical continuity with the cavity surface of the barrel bus distal power rail, and  
 has surface that is at the contact means of the first wall conductor assembly and, via said contact means, has continuous electrical continuity with forward wall conductor of said assembly, and  
 has surface that is at the contact means of the second wall conductor assembly and, via said contact means, has continuous electrical continuity with forward wall conductor of said assembly, and  
 maintains continuous electrical continuity between forward wall conductor of the wall conductor assembles and said power rail, and,  
   with the armature in the barrel cavity and power supplied to the power rails, 
 maintains a current path between the barrel bus distal power rail and  
 forward wall conductors of the wall conductor assembles; and  
   an aft current shunt that: 
 is located between the armature's propulsion bus and the armature's breach end, and,  
   with an armature in the barrel cavity, 
 is proximal barrel bus distal power rail, and  
 has surface at contact means of the first wall conductor assembly and, via said contact means, has continuous electrical continuity with aft wall conductor of said assembly, and  
 has surface at contact means of the second wall conductor assembly and, via said contact means, has continuous electrical continuity with aft wall conductor of said assembly, and  
 has continuous electrical continuity with the propulsion bus-aft shunt circuit means, and  
 maintains continuous electrical continuity between aft wall conductor of the wall conductor assembles and the propulsion bus-aft shunt circuit means, and,  
   with the armature in the barrel cavity and power supplied to the power rails, 
 maintains a current path between aft wall conductor of the wall conductor assembles and the propulsion-aft shunt circuit means; and  
   propulsion bus-aft shunt circuit means having: 
 a third barrel rail with continuous barrel cavity surface its length and that is: 
 located in, at, or proximal the narrow end of said barrel cavity distal the barrel buses of the wall assembles, and  
 proximal the barrel bus distal power rail, and  
 located parallel with said power rail, and  
 electrically isolated from said power rail, and  
 of length similar said power rail's length, and  
 at similar location along the barrel cavity length as said power rail; and  
 
 surface on the propulsion bus that has, with an armature in the barrel cavity, continuous electrical continuity with the barrel cavity surface of said third barrel rail; and  
 surface on the aft current shunt that has, with an armature in the barrel cavity, continuous electrical continuity with the barrel cavity surface of the third barrel rail; and,  
   said propulsion bus-aft shunt circuit means, 
 with an armature in the barrel cavity, 
 maintains continuous electrical continuity between the propulsion bus and aft current shunt of said armature, and,  
 
 with an armature in the barrel cavity and power supplied to the power rails, 
 maintains a current path between the propulsion bus and the aft current shunt of said armature; and  
 
   in which with 
 an outside power supply attached to said power rail connection means and  
 an armature in or inserted into the breach end of the barrel cavity,  
   the electric current path in the device effecting electromagnetic propulsion of the armature in the barrel cavity towards the barrel muzzle is extant and    the magnetic fields of the electric current in: 
 the barrel rails and  
 the wall conductor assembles'
 forward wall conductor and  
 aft wall conductor and  
 the barrel buses  
 
 interact with the electric current in the armature propulsion bus  
 creating forces therein 
 with cavity axis parallel, muzzle directed components  
 
 that propel the armature in the barrel cavity towards the barrel muzzle.  
   
   
   
       16 . Electromagnetic propulsion devices as claimed in  claim 15  wherein an armature is retained in the breach end of the barrel cavity for release and propulsion in the barrel cavity towards the barrel muzzle on application of sufficient power to the power rails.  
   
   
       17 . Electromagnetic propulsion devices as claimed in  claim 16  wherein the armature is retained at the cavity breach by a fuse pin which: 
 at one end is retained at one power rail and has electrical continuity therewith, and    at its other end is retained at the second power rail and has electrical continuity therewith, and    extends through an armature channel there between, and    with power supplied the power rails, provides a short circuit between said rails until vaporized and freeing the armature for traverse of the barrel cavity.    
   
   
       18 . Electromagnetic propulsion devices as claimed in  claim 15  but wherein the propulsion bus-aft shunt circuit means is comprised an electric current bus in the armature located proximal the current shunts therein and between and connecting the armature's aft current shunt and the armature's propulsion bus.  
   
   
       19 . Electromagnetic propulsion devices as claimed in  claim 15  wherein, 
 said barrel and barrel cavity has a twist so that:    right sections to the barrel and elements therein, 
 when taken at incremental increasing distance from a barrel reference point, have like shape, area, and angle relative to each other at fixed radii about a barrel axis, at incremental increasing angular displacement about said axis from an axial reference plane and the angular displacement per unite axial distance is constant; and  
   said armatures for use in said barrel cavity have therein an axis coincident said barrel axis 
 and have a like twist so that right sections to said armature and elements therein, 
 when taken at incremental increasing distance from an armature reference point,  
 
 have like shape, area, and angle relative to each other at fixed radii about the armature axis coincident said barrel axis at incremental increasing angular displacement about said armature axis from an axial reference plane and the angular displacement per unite axial distance is constant and identical to said barrel and barrel cavity constant.  
   
   
   
       20 . Electromagnetic propulsion devices as claimed in  claim 19  wherein the armature is retained at the cavity breach by a fuse pin which: 
 at one end is retained at one power rail and has electrical continuity therewith, and    at its other end is retained in the second power rail and has electrical continuity therewith, and    extends through an armature channel there between, and    with power supplied to the power rails, provides a short circuit between said rails until vaporized and freeing the armature for traverse of the barrel cavity.    
   
   
       21 . Electromagnetic propulsion devices as claimed in  claim 19  but wherein said propulsion bus-aft shunt circuit means is comprised of an electric current bus in the armature located proximal the current shunts therein and between and connecting the armature's aft current shunt and the armature's propulsion bus.