Arc ignition systems

Claim 2

An automatic system for striking an arc between first and second electrodes, which comprises: a third electrode having a polarity corresponding to the polarity of said first electrode, said third electrode being positioned normally out of contact with said second electrode and mounted for movement toward and away from said second electrode, and actuating means rendered effective upon the application of a selected voltage across said first and second electrodes for moving said third electrode into contact with said second electrode and for moving said third electrode upon contact with said second electrode away from said second electrode to strike an arc.

Claim 3

An automatic system according to claim 1, wherein said actuating means includes a relay connected to said third electrode for moving said third electrode into contact with said second electrode upon application of the selected voltage, said relay being rendered inoperative upon said third electrode contacting said second electrode to permit the third electrode to move away from said second electrode to strike an arc.

Claim 4

In a carbon arc lamp wherein an arc is established between first and second electrodes by applying a selected voltage across the electrodes and wherein said selected voltage is greater than the operating voltage which is present when an arc is established, an arc striking ignition system, comprising: threshold-operated sensing means coupled to said selected voltage for providing an output in the presence of a voltage greater than the operating voltage to indicate the absence of an arc between the first and second electrodes; an additional striking electrode having a polarity corresponding to the polarity of the first electrode and mounted for movement toward and away from the second electrode; and actuating means rendered effective by the output of said sensing means for moving the striking electrode into contact with the second electrode.

Claim 5

In a carbon arc lamp wherein an arc is established between first and second electrodes by applying a selected voltage across the electrodes and wherein said selected voltage is greater than the operating voltage which is present when an arc is established, an arc striking ignition system, comprising: threshold-operated sensing means coupled to said selected voltage for providing an output in the presence of a voltage greater than the operating voltage to indicate the absence of an arc between the first and second electrodes; an additional striking electrode having a polarity corresponding to the polarity of the first electrode and mounted for movement toward and away from the second electrode; and actuating means rendered effective by the output of said sensing means for moving the striking electrode into contact with the second electrode.

Claim 6

A lamp according to claim 3, further comprising means for establishing a selectable threshold voltage for the sensing means.

Claim 7

A lamp according to claim 4, further comprising means for damping the movement of the striking electrode so that shock to the striking electrode upon contact with the second electrode is lessened.

Claim 8

A lamp according to claim 5, wherein said actuating means comprises a relay connectable to a source of variable voltage and operatively coupled to the striking electrode, and said damping means comprises, in combination, means for varying the voltage to the relay and a spring affixed to the striking electrode, said spring being compressible when the relay is actuated.

Claim 9

A lamp according to claim 6, further comprising means for mounting the spring to bias said relay and said striking electrode away from the second electrode in the absence of an output from the sensing means.