AU784922B2 - Magnetic pulsing, plasma welder-cutter - Google Patents

Description

-1 This complete specification based on provisional application PQ 6730 of the 6/4/00 is a plasma welding/cutting system that is based on a pulsing high strength magnetic coil that achieves up to 100 tesla magnetic field strength for about 10-4 seconds and a series of these pulses heats gas around pulse coil to up to 20,0000K which then directs heated plasma through a tapering hyperbolic passage surrounded by a secondary magnetic coil to separate charges and build a like ion film on internal surface which thermally insulates hot plasma from internal surface of hyperbolically tapering passage 10 and streamlines flow through hyperbolically tapering passage and through exit nozzle. This jet is like a flame from a conventional oxygen-acetylene torch but jet is more intense and much higher temperature heat. Jet melts metal like a electric arc as with stick S" electrode but without the massive amounts of light and Ultra Violet Rays which are blinding and make welding troublesome. So plasma jet welding can be observed with minimal eye shielding. Specially designed oxygen-acetylene goggles are adequate and these allow observation of weld site as well as surroundings so visibility is not a problem as with conventional electric arc welding. Basically plasma is heated magnetically with no current flow through plasma which fills and empties outer electron shell orbitals of gas atoms or ions which hence produces the blinding arc light. Conventional stick (flux coated) electrodes can be used as filler metal as with fusion welding with oxygen-acetylene torches but is as quick as electric arc leaving deposited metal with slag covering as protection as with electric arc welding but with the ease and convenience of oxygen-acetylene fusion welding. A conventional arc welder loses up to 70% of its energy input as welding light flash (over 20%) and convection loses to atmosphere. This system using the pulse coil is -2rated at over 80% efficient at heating metal and for a standard input of 240 volts A.C. at 15 amps input to welding system, system is equivalent to a 400 amp conventional electric arc welder. The pulse coil is typically 4x layers of 20x spirals of copper strip which is 3.5mm. wide and Imm. thick which is feed (typically) by a 24 volt D.C. Capacitior that holds .18 coulombs of charge and discharges of charge into pulse coils in about .09 milliseconds so that over 100 tesla magnetic field strength is felt on surface of pulse coil which goes directly to heating surrounding inert gas (prefer- 1 0 ably Argon but Helium or Nitrogen can be used Carbon Dioxide is to be avoided due to decomposition). Figure 1 shows the coil with 1 the spiral strip copper which is 3.5mm. by 1mm. thick heated to about 6000C and formed into a tight spiral on a stainless steel rod former or copper tube slitted by spiral lathe cut slits with spirals spaced and joined 5 (by welding) and the coil assembly filled with Nitride powder 2 (Zirconium and Tantalum) that has been ball milled to less than .lpm. (microns) and sintered at about 1,000oC in Nitrogen atmosphere to shrink powder around coil leaving about of nitride around outer copper spiral. Joins in spiral 5 and at other end mean ceramic spacer bushes 3 can accurately position copper rings 4a,4b and 4c and ceramic bushes between rings position coils. Drawing is about 2x scale. Pulse frequency varies from pulses per second to 1,400x pulses per second at maximum output at 2.16 Joules per pulse. A tranformer exists in unit to step 240 volts A.C. then a diode bridge rectifies the 20 volts A.C. to 24 volts D.C. with the aid of a bridging capacitor that smooths the rippling current. This 3,600 watt output goes principally to a large 24 volt D.C. capacitor which is continually filling and being discharged as 2.16 Joule pulses into pulse coil that creates the up 3 to 20,000oK plasma as a welding or cutting jet. The capacitor runs at 24 volts (as designed but voltage can vary from 20 volts to volts)D.C. and holds (about) .18 coulombs of charge (being 8.333 x 10-3 Farads when charged). The capacitor is two layers of thick Al-foil about 44.6 meters long and about 44 centimeters wide separated by sparcely spaced Alumina grit of 320# openings per inch of mesh screen) which is then filled with moist Barium Titanate powder and slightly compacted between rubber rollers and then the contents are dried facing infra-red ray lamps on one outer surface 10 of Aluminium containing Barium Titanate and spacing Alumina grit thus drying out any moisture between the Al-foil layers. One layer of Al-foil has edges trimed by about .5mm. of either side so edges cannot contact. The 2x layer Al-foil of about 100 micron (10- 6 meters) is separated with a sheet of polyethylene plastic film or vishane. (moisture proofing film for concrete floor slabs) The capacitor is discharged from 30x times to 1,400x times per second with a discharge time of about .09 milliseconds with up to 3,000 watts of pulse energy going to heat gas to plasma and by the use of a variable Disc motor (described latter) the pulse frequency can be varied from 30x pulses per second to 1,400x pulses per second (Figure 3 of PR1125 of the 31/10/00) so very fine welding can be achieved with the right exit nozzle from the plasma chamber around pulse coil. All pulses are about 2.16J. as designed for 24 volt D.C. sytem for capacitor of .18 coulomb discharge. Figure 2a shows the assembly of capacitor by 2x layers of Al-foil 6 with sparsely spaced spacing grit 7 about 320# (25pm. or microns) with Barium Titanate powder 8 filling gaps between 2x Al-foil layers and 9 the insulating plastic film about .4mm. thick and this is wrapped in a spiral on a 100mm. diameter cardboard former 11 as a spiral 10 giv- -4ing a final Diameter of about 200mm. with capacitor being about 44x centimeters long. Thin copper tabs 16a and 16b are soldered to Al-foil for connection by a 4x component solder(15 to 25 weight% Silver, 30 to 50 weight Tin, 25 to 35 weight Cesium and 10 to 20 weight Aluminium) with a liquidus range at less than 2500C with a flux of Silver Fluoride (about 25 to 35 weight and Tantalum Fluoride (about 40 to 60 weight and Cesium Fluoride (about 25 to weight as a paste or solution in acid Hydrofluoric acid at volume/volume strength. Figure 2c shows a graph of Energy of 10 Electron through pulse coil on vertical axis 12 and position of Electron as it progresses through length of pulse coil 13 with the would be resistance energy fall off line 14 which is about a 13.2 Volt drop and about a would be 55% of capacitors energy but due to S high magnetic strength of the pulse coil energy goes to heating surrounding gas before electric resistance energy is lost and so process is over 80% efficient in generating plasma instead of the would be 45% efficient energy to plasma energy as seen by hyperbolic (non-linear) energy drop off as electron energy (pressure) drops hyperbolically as it progresses through pulse coil. The pulsing apparatus for capacitor roll assembly in Figure 2 is very similar as Figure 3 in Provisional application PR1125 of the 31/10/00. Figure 3a is in 6x parts being of the ejection tube for completing the circuit for main pulse capacitor to discharge capacitor within .1 milliseconds and as well as the magnetic circuit that triggers the release of ejection tube from tapered solenoid around ejection tube. In Figure 3a1 item 17 is the thin hardened, toughened thin steel impacting disc head which impacts with 18 the hardened, toughened thin steel impacted (stationary) disc head to close circuit in less than .1 millisecond Lead 19b is to I 5 capacitor roll 20 with lead 28b to moving impact head 17. Lead 19a completes circuit to impact heads (17,18) and capacitor roll 20 to pulse coil 1 with lead 28a to stationary impact head 18. Item 21 is the light tube that houses the light ceramic rod magnets 24 through tapered solenoid 22 (activated by capacitor roll which only absorbs about .18J. of energy per pulse as resistance of Solenoid 22 (about milli-Ohms) is considerably higher than the 6.6 milli-Ohms of pulse coil that discharges in about .1 ms.) that ejects tube assembly at about 3x meters/second. Re-locating spring 23a brings back tube assembly to initial position ready for next pulse and acts against stationary barrier 25. Stationary impacted head 18 is cushioned on impact by a hard rubber cushion 27 against fixed plate or barrier 26 and this impacted head 18 is relocated by spring 23b also acting against fixed barrier 26. Tube assembly 23a,21,24,17 and 28b must be equal to or less than 20 grams so up to 4x m./s.

ejection speeds can be attained so less than .18 Joules is drained from capacitor role per pulse. In Figure 3a2 the slide for tube assembly is shown from the side with runners or slides 29 and support rings 30 and 4x brazed spots 31 per rings (depending on the number of wire runners one braze spot per wire, per ring). In Figure 3a3 the slide for tube assembly is shown from front with 29 the wire runner and 30 the support ring and 31 the braze spots.

Figure 3a4 is the magnetic circuit that closes the switch for capacitor roll that discharges into tube assembly ejection solenoid 22 (in Figure 3a1). The sintered iron loop with active solenoid 32 around iron section that has holes 38 for gas cooling of iron and solenoid 32 around that particular section of iron in magnetic circuit. Item 33 is the rotating iron disc such that lobes 33a complete magnetic circuit 8x every rotation hence discharging capacitor -6 roll into pulse coil. Item 34 is the iron slug arrangement (see Figure 3a6 for detail) that is attracted when magnetic circuit is completed when a lobe 33a is in position between gap in Iron loop Item 36 is the Iron collar around Iron slug connector 34 giving magnetic field conveyance when magnetic circuit is closed.

Item 37a is electrical lead to stationary electrically isolated Iron slug and 37b is to moving Iron slug, also electrically isolated that acts such that when magnetic circuit is complete and moving Iron slug (Iron-Silicon) is attracted to stationary Iron slug com- S10pleting electrical circuit that very partially discharges (about .18 Joules) into ejecting solenoid 22 of Figure 3al. Figure 3a5 is the spinning or rotating Iron disc 33 such that triangular lobes 33a fill gap in Iron loop 35 of Figure 3a4 thus completing magnetic circuit. The triangular head plunger 39 is pushed into triangular *r lobe gaps to stop rotation of iron disc 33 so iron disc is in a disengaged position not allowing discharge to ejection Solenoid 22 and magnetic circuit is open (for safety). So when solenoid 44 is active and plunger head 39 is withdrawn by attraction of solenoid 44 on permanent magnets 45 in retracted motion 46 disc 33 is free to rotate and pulsing starts. So when solenoid 44 is off spring 42 pushes head 39 with roller 41 rolling over lobes 33a and rubber sides 40 dampen impact so pulsing stops with lobes 33a in a disengaged position. Figure 3a6 is the Iron slug electrical switch 34 in the magnetic circuit with 36 the Iron band over this disconnected or disjunct portion of Iron loop in magnetic circuit with 34a the iron slug housing and 34a5 the stationary Iron slug in electrically insulating liner 34a2 to electrical lead 37a which makes electrical contact with moving slug 34b5 when magnetic circuit is complete. Moving slug 34b5 is in housing 34b in Iron loop, elect- 7 rically isolated by electrically insulating liner 34b2 with re-locating tension activated spring 34b3 pulling slug 34b5 back when magnetic circuit is open and electrical lead 37b to slug 34b5 completes electrical circuit when magnetic circuit is closed and moving slug 34b5 contacts slug 34a5 being magnetically attracted together. Figure 3b1 is of the D.C. disc motor that drives the iron disc 33 of Figure 3a5 with straight 24 volts D.C. from rectifying bridge going into motor loops (single layer of .35mm. copper enamel wire of 60 loops) and 16x poles (8x per side). Internal radius of .oboo 1 0 Aluminium support disc 47 is 30mm. and outer radius is 100mm. with 48 the 60x loops (single layer). Shaft 49 rotates 49a and iron disc 33 is rotated between 210 R.P.M. and 10,500 R.P.M. governed by the o0@ pole foot 52 strength that can vary from 400 gauss to 8,000 gauss by a potentiometer on a sintered fused silica disc 56 with holes 56a for air cooling and resistance wire windings (radial) 55. Poles have 210 strip windings 51 and the 16x poles in series absorb watts amps at 24 Volts and potentiometer contact position governs whether the full 75 watts goes to 16x poles and pole strength is 8,000 gauss or only a fraction of this goes to poles and most of the power is consumed as resistance heating in windings of potentiometer and motor (about 100 watts rating at 24 volt D.C.) achieves 10,500 R.P.M. and maximum output to pulse coil 1. Single headed arrows show air cooling flows 53 generated by rotating fan (plate of blades) 54. Spokes 50 support Aluminium disc 47 on which 60x radial loops 48 are wound with current flow shown with 2x headed arrows and magnetic field lines facing radial winding loops with 4x headed arrows. Figure 3b2 shows the tapered iron foot poles 52 (sintered Iron powder) which face radial loops 48 with iron spacer 57 for return magnetic circulation. Figure 3b3 shows the sintered 8 iron expanded (tapered) foot 52 with 4x headed arrows as magnetic field lines and 51 the (2mm. x .5mm.) strip windings (with the 2mm.

length in the vertical direction) and the Aluminium former 58 for holding the strip windings along length of tapered iron (sintered powder) foot. Figure 4 is a schematic diagram of the welding system with electrical power flow and distribution. Item 59 is the 3,600 watt (240 volt A.C. to 20 volt A.C. output) Transformer which goes through rectifying bridge 60 and bridging capacitor with output 61 and 62 Lead 61a and 62a go to capacitor roll 20 which 10 is connected to tube plunger assembly 63 of Figure 3al which is activated by lead 61c and 62c through magnetic circuit 64 of Figure 3a4 with leads from capacitor roll 61b and 62b. Magnetic circuit 64 is activated by motor 66 of Figure 3b1 by lead 61d and 62d from main lead 61 and 62 and motor 66 rotates iron disc 65 of Figure 153a5. The disengage plunger 74 of Figure 3a5 is activated by leads 61e and 62e from main lead 61 and 62. The position fixing adjustment 67 of potentiometer of motor 66 sets power to poles of motor and motor speed and pulse rate and power output of plasma jet 76.

o e When motor 66 is active plunger 74 is withdrawn by leads 61e and 62e to solenoid 44 and magnetic circuit 64 opens and closes and tube plunger 63 is active and pulse energy to coil 1 through 68 to welder gun assembly and inert gas flows 77 to nozzle where pulse coil energizes and produces plasma with a double hand switch 69 and in handle 75 serious burns are easily avoided by this double device and carelessness is thus minimized. A Tapered converging hyperbolic wound coil 71 separates charges and negative charges (electrons) which build on internal surface of hyperbolically tapering sintered fused Silica powder sheath 73 and plasma glides along this like ion (negatively charged) film 78a in Silica 9 Sheath 73 and through Sintered (Refractory oxide) Alumina nozzle 72 with ion film 78b again giving heat shielding and assisting plasma flow. By setting the orifice size or using different nozzle tips and setting the (inert) gas pressure through gun, welder can do cutting or welding. The gun head (which is changeable) or coil 71 and sheath 73 can be changed for different operations and different power outputs. To maintain a maximum exposed magnetic field strength of 10 gauss (standard field strength for electric welder next to human body parts) to human body parts handle is further than 1 0 100mm. from any point of pulse coil 1 and when feeding filler wire into a weld site fingers or hand must be further than 100mm. from any point of pulse coil 1. Note that capacitor Spiral 20 must be held tightly in steel (sheet steel) outer casing to stop repulsive (charge) delamination. Figure 5 is of the 240 volt A.C. Tranformer which offers weight and size reduction for the portable welding unit. Cylindrical sleeves or thin hollow sections are made from fine Iron powder mixed with ferro-Silicon powder that has been pressed to high pressures (up to 107 Pa.) then taken from mould e:oe e (slid out) and sintered in inert atmosphere (Hydrogen,Helium or Argon preferably) at over 500oC. Individual sintered iron sleeves are preferably less than 1.6mm. thick. If final tolerances of diameter and length are slightly out, individual sleeves can be machined to exact tolerances in a metal lathe. A Side veiw in Figure shows the hollow internal sleeve 79 onto which spools with windings 82 and 83 go separated by internal rings 81b and sealed by external rings 81a with outer sleeves 80 sealing Transformer. Spools for windings are mulched fibre glass (chopped strand matt) pulped in epoxy resin and set over mould and allowed to set. The set incomplete spool is then machined in a lathe for tolerance attainment.

10 Spool can handle temperatures of up to 2500C. Input air 84a enter into first windings' compartment through hole 84 and cools secondary windings and 82 and warmed air 85a exits through hole 85 on other side of transformer. Similarly for primary windings air 84a1 enters through hole 84b and cools primary windings and warmed air 85a1 leaves primary winding compartment by hole 85b. Figure 5b is the same as Figure 5a but is a slice away isometric veiw of transformer showing the whole spools supporting primary windings 83 and secondary windings 82. Figure 6a is of the variable speed D.C.

.ooooi motor that generates the high frequency of the high magnetic field strength pulses as described in Figure 3b1 with 47 the Aluminium disc the windings 48 are on being supported on shaft 49 by spokes from the central bush 100 on threaded section of shaft 101 bet- Sween threaded collars 102. Pole windings 51 are around thin iron strip of top part of sintered iron strip section with wide tapered foot 52 transmitting variable magnetic field to windings 48. Air flow 53 through motor cools motor and is generated by fan 54 held between threaded collars on threaded part of shaft. Sintered Silica disc 56 with holes 56a allows air cooling of 3x parallel sets of winding loops 55 which vary power to pole windings 51 and hence speed of motor. Plastic isolator bushes 107 hold connection to resistance windings 55 for power control to poles as 3x piece connection assembly 108 (which is a negative Terminal) slides in 3x grooves or circular slots 107a in side Aluminium casing 87 for supported resistance windings 55 for pole power control. Front Aluminium casing or cover 88 is joined to thick side Aluminium cover of motor 86 and these are joined together and to housing 89 motor by bolts 90. Bolts 91 holds side cover 87 to side motor housing cover 86. The bearing 92 is in housing 93 bolted to right motor cover 88 11 by bolts 97 which also hold commutator plate 96 behind plastic isolation plate 99 with bolt 97 through plastic isolation bush 98.

Commutator housing 103 which holds bronze roller commutator. Right bearing edge fits against shaft elevation 95 which is next to square internal coupling 94 end of motor shaft 49 and left bearing 104 is in housing 105 with threaded collars 106 on threaded left end of shaft pre-loading and loading bearings of motor system. The positive and negative terminal connections through side of motor are clearly shown. On left side commutator plate (brass) is not 10 connected with bearing housing (left) but plastic isolator bushes are still required to isolate connection to motor armature disc windings 48 from Aluminium casing 86. Figure 6a2 shows the commutator assembly which is a plastic cylinder or casing 103 machined with screw bolt 110 to screw into central Aluminium bush 100 on shaft and is fixed by lock nuts lla and Illb or threaded collars with lead connection 112 going into plastic casing 103 with a spring 109 pushing on brass cylinder 116 and lead 112 joined in rod 116 at point 117 (by soldering). Slots or 'keys' 114 are cut in brass rod 116 and plastic casing 103 at one end with plastic 'key' section inserted to allow brass rod commutator assembly 116 to slide and be adjusted. Bronze roller 113 on end of brass rod 116 is on stainless steel thin rod held by nuts 115 and roller 113 rolls over commutator plate 96 (brass) making electrical contact. Figure 6bl is a side view of the pole assembly mounted on casing 86 by bolts 120 into thin plate of iron strip 52a and iron foot 52 is shown. Windings 51 around thinb iron section are shown with Aluminium keepers 58 holding windings 51 and keepers 58 being glued to Iron strip thin section. A backing plate 119 holds iron strip by bolts to casing 86 and Aluminium spacers 118 keep pressure and form 12 on Aluminium keepers 58. Figure 6b2 is a plan view of mounting system for poles and intermediate iron strips 57 with backing plate 119 to poles with bolts 120 and backing plate 119a to strips and bolts 120a holding backing plates 119a. With a faint outline of the Tapered pole feet 52 on other side of casing 86 being seen.Figure 7 is of the dismantable,changeable torch head that houses the pulse coil 1. Leads 61 and 62 connect to connector sockets 128 (gold exchange plated) to clay ceramic holder 127 (fired at up to 1,000oC) with gold plated electrical socket connectors which support pulse coil 1. A thin Sintered Silica sheath formed on a mould (high temperature alloy) by forging form at 1,400oC is no more than .3mm. thick. Around this sintered iron sheath 130 is gas cooling through longtitudinal grooves 131 for cooling gas 140 to flow between iron sheath 130 and tapered hyperbolic coil 71 which helps separate charges and builds negative ion (electron) film 78a in i. sheath 73 and negative ion (electron) film 78b extends to nozzle 72. Where plasma jet 76 exits and is the welding heat source being heated inert gas 77 which is also the cooling gas 140 and welding gas shroud emerging from holes 139 around plasma jet 76. Brass handle 121 is the central structural component of torch head with brass socket holder 126 with ring 125 between 126 and 121 sealing inert gas. Epoxy resin in holes 122 in 121 allows insulated wires (plastic coated) from coil 71 to 123a and 123b to be connected to leads 61 and 62 and plastic covered wires go through gas flow input channels 124 to cool iron sheath (externally) and coil 71 and magnet rings 132 and channel 124 also feeds gas to plasma pulse coil 1 region. Magnet rings 132 with circular fields (as in rings of 71,475/00) with anti-clockwise fields (seen from left) with central holes 132a (drilled with Tungsten Carbide drills S- 13 at up to and over 30,000 and outer grooves (cut with small diamond wheel) 132b for gas cooling 140. Glass wool fibre (matt or woven cloth) insulates coil 71 from rings 132. Poly Tetra Fluoro Ethylene ring being injected moulded with socket 135a and 135b in mould makes connection with coil 71 and exit lead 123a and 123b which go to lead 61 and 62. Holes in sintered iron sheath 130 flange allows cooling gas to flow in groove 131 between sheath 130 and coil 71. Silica sheath 73 can be taken out and easily replaced in dismantable Torch head. Sintered Alumina connector 137 screws 10 onto threads of brass structural torch component 121 with outer sintered Alumina cover 138 screwing onto this. Threads are cut with small diamond wheel with 600 thread point of about 20mm. diameter spun at 30,000 Holes 139 in front of outer Alumina cover 138 are drilled with Tungsten drills at up to and over 30,000 Torch head coils 71 and assembly as distractable from 121 and different size heads can be used as for light welding a field of up to .5 tesla from 71 needs to be applied to iron film 78a and coil 71 needs 150x loops of 7mm. x .5mm. strip with head being about 30mm. in diameter and 100mm. long. For heavy welding and cutting field needs to be up to 1.0 tesla from 71 needing applied ion film pressures of up to 4 x 105 Pa. with up to 300x loops of 7mm. x strip with head about 35mm. in diameter and 120mm. long. For heavy cutting 2.0 tesla from 71 is required with up to 600x loops of 7mm. x .5mm. strip with head about 45mm. in diameter and 140mm.

long. Nozzle orifices diameters in the case of intermediate size heads of 300x loops can make the difference between welding and cutting (smaller nozzle orifices faster ion speeds and this suits cutting application where larger orifices of nozles are more for welding). The iron sheath 130 means that the magnetic field on the 14 edge of the coil 71 is transmitted to edge of Silica sheath 73 at full strength by the Ferritic Iron sheath 130 and gives support for the thin Silica sheath 73. The handle connection 70 and 69 are for the separate terminal connections of +ve 61 and -ve 62 leads and both have to be depressed for system to give plasma jet giving extra security for safety purposes. Also when this circuit is closed by the two levers (69 and 70) a gas solenoid is activated to allow gas (inert gas) to flow to torch head. Tags are cut into the up to 100x micron Aluminium foil as in Figure 8a with bottom layer of capacitor 6b (showing edge over-lap) and tag 141b with top layer 6a and tag 141a with isometric of Figure 8b showing tag 141b of lower foil layer 6b and top foil layer 6a with tags 141a at other end for separate terminal connection (61 and 62). Plastic intermediate film 9 is shown. Voltage from transformer can be from 20 volts to 70 volts D.C. in which case the resistance and discharge time have to be re-designed and system adapted accordingly. The advantage of this system is that Nitrogen can be used as a inert gas for welding in short weld times and only speciality steels require the expensive inert gases like Argon or Helium. Even Copper with fast welding procedures can utilize Nitrogen. With system of welding whic has the speed of electric welding the temptation is to move weld slowly but adverse metallurgical microstructural consequences result so it is neccessary to move weld as fast as possible and the intense plasma jet is certainly adapt to handling this type of procedure. (Summary of Invention) This invention is based on a series of very brief (less than Ix ms.) capacitor discharges for a capacitor into a strip wound coil that generates up to and over 106 gauss magnetic field which explosively heats gas over the surface of the pulse coil to up and over 20,000oK so that hot plasma is magnetically directed down hyperbolically tapered passage through nozzle where this plasma jet can weld or cut metal (particularly) without generating large amounts of blinding U.V. light and still weld at the speed of electric arc welding. The pulse coil is copper strip preferably made from slitting copper tubes in a spiral pattern with the ends of these spiral slitted copper tubes joined at each end increasing the number of low diameter copper loops in series with loops set and sintered in fine refractory Nitride powder (such as Zirconium and Tantalum). This affective high current from the dis- 10 charging capacitor generates the high magnetic fields on the surface of the pulse coil. The capacitor is of 2x Aluminium foil sheets up to 100 microns thick with Alumina grit which sets the spacing e S between the two oppositely charged Al-foils filled with Barium Titanate Paste with about .5mm. overlap of Al-foils on either side with tags on each side on each foil for multiple low resistance connections. Discharge series or sequences are achieved by a variable speed motor turning Ferrous iron rotor with lobes through gaps in magnetic circuit and activates a switch to solenoid that ejects plunger to complete circuit for discharge to pulse coil. The gap in magnetic circuit occurs again and spring de-activates switch in magnetic circuit and plunger in solenoid is pulled back also by spring waiting for next iron lobe to complete magnetic circuit and activate magnet switch to solenoid,plunger contact which discharges capacitor. The variable speed motor is a D.C. disc motor with radloops over a support on a shaft by spokes to Aluminium disc with no centre and poles on each side of Aluminium disc are sintered iron strips with expanding foot for conveying magnetic field to loops on Aluminium disc with a variable contact silica disc outside out-side motor with resistance windings controlling power to pole S- 16 windings and magnetic field to windings of Aluminium disc and speed of motor and hence number of iron lobe contacts in magnetic circuit and number of plunger contacts to discharge capacitor. The pulse coil is mounted in a dismantable torch head which has a hyperbolically Tapered thin Silica sheath (hot forged after sintering) supported in a ferritic sintered iron former with external longtitudinal grooves for gas cooling of iron former and laterally wound (perpendicular to length of former) thin strip windings with fields on exchangeable torch heads varying from .4 to 2.4 tesla for weld- 10 ing to higher pressure (plasma) ion jet cutting. A Brass central structure support pulse coil socket and allows gas entry (through solenoid valve when circuit is complete) and is sealed by rubber e ring and Alumina cover for supporting Alumina nozzle at front of head with holes at front for cooling inert gas shroud around plasma jet. Magnet rings are around this directing coil around Silica sheath and helps ram electrons and plasma down Silica sheath and through nozzle with rings having a ciruclar magnetic field.

Heavy leads go to torch head and electrical resistance of circuit must be low so discharge time is short and discharge voltage on design of system can be from 20 volts to 70 volts For safety a spring loaded press contact for both the Positive lead and Negative lead in the handle for double security and safety to avoid serious burns from plasma jet. Plasma jet gas is preferably inert gas in most economical form being Argon but Helium can be used and for low cost rapid mild steel welding and cutting Nitrogen can be used but welding must be fast where gas is primarily plasma jet and secondly cooling gas and (relatively) inert gas shroud around plasma jet and welding (cutting) zone. The transformer from the alternating current power supply to step down to low voltage capacitor 17 voltage (as well as other related components like motor that drives discharge and Silica sheath coil) has to be light and compact and this is achieved by Sintered Iron powder (with some Ferro- Silicon powder) cylindrical sleeves as concentric rings with fibre glass and epoxy resin spools holding windings and iron rings are completely around winding spools with air input holes to winding spools from side and air output holes on other side of transformer for cooling air flow through transformer around winding spools.

(End of Summary of Invention) .o

Claims (9)

1. A capacitor Discharge,pulsing coil welder/cutter having a capacitor that generates high magnetic fields on the surface of a pulse coil by brief discharges (less than Ix millisecond) with mag- netic fields on surface of pulse coil of up to and over 106 gauss that explosively heats surface gas to up to and over 20,000oK so that hot plasma is magnetically directed down hyperbolically tapered passage through nozzle where this plasma jet can weld or cut metal (particularly) without generating large amounts of blinding light and U.V. light and still weld at the speed of electric arc welding with pulse coil of copper strip (preferably made from slitting copper tubes) joined at each end thus increasing the number of low diameter copper loops in series with loops set and sintered in fine refractory Nitride powder (such as Zirconium and Tantalum) with discharge capacitor being of 2x Aluminium foil sheets of up to 100 microns with Alumina grit between them which sets the spacing between the two oppositely charged Al-foil sheets filled with Barium Titanate Paste with about .5rrum. overlap of Al- foil sheet on either side with tags (with special low temperature 20 solders and fluxes used for connection) on each foil sheet for multiple low resistance connections so discharge series or sequences are achieved by a variable speed motor turning Ferrous Iron rotor with lobes through gaps in magnetic circuit that completes magnetic circuit and activates a switch to solenoid to eject plunger to complete electrical circuit for discharge to pulse coil so that gap in magnetic circuit occurs again and a spring de- activates switch in magnetic circuit and plunger in solenoid is pulled back also by the spring while waiting for next Iron lobe to complete magnetic circuit and activate magnet switch to solenoid, 19 plunger electrical contact which discharges capacitor with variable speed motor being a D.C. disc motor with radial loops over supported annular Aluminium disc (support by spokes from shaft centre) and poles on each side of Aluminium disc are sintered Iron strips each with a expanding foot for conveying magnetic field to radial loops on Aluminium disc with a variable contact Silica disc outside the motor with resistance windings controlling power to pole windings and magnetic field strength of windings of Aluminium disc and so speed of motor varies for magnetic circuit completion and number of Iron lobe contacts (completions) in magnetic circuit and number of plunger contacts to discharge capacititor per second varies so the pulse coil varies in power output, the pulse coil being mounted in a dismantable torch head which has a hyperbol- ically Tapered thin Silica sheath (hot forged after sintering) 15 supported in ferritic sintered Iron former with external longtit- S udinal grooves for gas cooling of Iron former and laterally wound (perpendicular to length of former) thin strip windings with fields on exchangeable torch heads varying from .4 to 2.4 tesla for welding or to higher pressure (plasma) ion jet cutting so that *20 torch head has a brass central structural support for pulse coil go" socket and allows gas entry (through solenoid valve when circuit is complete) and where torch head is sealed by rubber ring, and Alumina cover for supporting Alumina nozzle at front of head with holes at front for cooling inert gas shroud around plasma jet and around a sheath coil having outer magnet rings, with magnet rings having circular fields which ram and direct electrons and plasma down Silica sheath and through nozzle with Torch head having heavy leads connected for low electrical resistance so discharge time of capacitor is short and discharge voltage on design of system is 20 from 20 volts to 70 volts D.C. and handle for torch head assembly has double spring loaded press contact for both positive lead and negative lead in the handle for double security and safety to avoid serious burns from plasma jet and plasma jet gas being preferably inert gas such as Helium (in preference to Argon which also can be used for welding and cutting) while for low cost rapid mild steel welding and cutting Nitrogen can be used (for rapid welding of mild steel and Nitrogen also serves as secondly cooling gas as a relatively low cost semi-inert gas shroud around plasma jet for IO welding and cutting) and system has a low weight, compact transformer running off alternating current power supply to step down to low voltage capacitor voltage (as well as other releated components like motor that drives discharge and Silica S: sheath coil) with transformer having concentric sintered Tron (or even sintered Ferro-Silicon powder) cylidrical sleeves as concen- tric rings with fibre glass and epoxy resin spools holding windings with Iron rings being completely around winding spools and air input holes to winding spools from side and air output holes on other side of transformer for cooling air flow through transformer ."20 around winding spools.

2. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by Figure 2 and Figure 8.

3. The capacitor Discharge, pulsing coil wleder/cutter as claimed in claim 1 is further characterised by pulse coil of Figure 1.

4. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by Discharge system of Figure3. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by Magnetic circuit of Figure 3a4 and Figure 3a6. 21

6. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by Variable Speed motor of Figure 3bl and Figure 3b2 and Figure 3b3 and Figure 6.

7. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by Dismantable torch head of Figure 7.

8. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by low resistance leads of Figure 4. IO 9. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by double lever switch safety system of Figure 4.

10. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by inert gases for plasma jet I5 and cooling and protective gas shroud around plasma jet utilizes low cost Nitrogen for Mild steel welding at fast welding speeds.

11. The capacitor Discharge, pulsing coil welder/cutter as claimed in claim 1 is further characterised by compact transformer of Figure ."20 12. A capacitor Discharge, pulsing coil welder/cutter substaint- ially as herein described with reference to accompanying drawings. GEORGE ANTHONY CONTOLEON 7TH.,MAY,2006. APPLICANT DATE