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US 6,635,842 B2Granted
Electric arc equipment
AssigneeGoodwin Air Plasma Limited
InventorDavid E Goodwin
Life of this patent
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AssigneeGoodwin Air Plasma Limited
InventorDavid E Goodwin
Estimating the term…
The invention relates to electric arc processes particularly for underwater use. Electric arc processes effected under water ordinarily operate at a voltage of 20 or 30 volts, with an open circuit of e.g. 50 volts, and are at a level that does not pose a serious risk to the diver. Such as plasma arc cutting has typical voltages of 100-200 volts, and an open circuit voltage of 200-400 volts, and can put a diver at considerable risk of electric shocks at a level that can be life threatening. The object of the invention is to avoid such risks, an objective met by electric arc equipment comprising an earthed safety electrode strategically positioned close to the torch of the electric arc equipment, to create the closest earth to which current could flow, but without the striking of an arc between a torch electrode and the earthed safety electrode.
Underwater electric arc equipment in which an electric arc is struck as between a primary electrode and a workpiece, through the intervening conductive medium of water comprising an earthed safety electrode positioned in relation to the primary electrode of the equipment to create the electrically closest earth to which current could flow through the conductive material from the primary electrode without the striking of an arc between the primary electrode and the safety electrode.
Dependencies are inferred from the claim text.