Automatic tipping-off apparatus for a high-intensity-discharge arc tube

Claim 1

Tipping-off apparatus for hermetically sealing the exhaust tubulation of a dosed and otherwise processed arc tube for a high-intensity-discharge device, said tipping-off apparatus comprising a portion of a fabricating apparatus for said arc tubes, said fabricating apparatus including a plurality of arc tube holding members each mounted about the peripheral portion of a turret member and being sequentially indexable in a stop-and-go fashion to and from a plurality of operating stations located about the periphery of said turret, said arc tube just prior to being tipped-off comprising an elongated, tubulated body having electrodes operatively positioned proximate the sealed ends thereof with a predetermined discharge-sustaining filling contained within said arc tube body, said arc tube body having an elongated exhaust tubulation projecting laterally therefrom and opening into the interior thereof, said tipping-off apparatus positioned at one of said operating stations and each of said arc tubes upon being indexed into said tipping-off operating station being retained on said turret by its exhaust tubulation with the arc tube body retained in a vertical orientation and with the atmosphere within said arc tube and said tubulation being a small charge of inert ionizable starting gas, said tipping-off apparatus comprising spring-loaded jaw means movable into retaining position on opposite sides of said arc tube, the spring loading on each of said jaw means being slightly different so that absent the retention of said arc tube by its exhaust tubulation, said arc tube would be moved a predetermined distance by said jaw means; burner means movable into position about the tubulation of said arc tube and operable to heat said tubulation to a softened status at a location proximate the body of said arc tube, and when said tubulation has been sufficiently softened by the heating from said burner means, the spring loading on said jaw means acts to move said arc tube a predetermined distance with respect to said retained tubulation to form a hermetic tip portion of said tubulation; timing means for controlling the movement of said jaw means and said burner means upon said arc tube being indexed to said tipping-off station; jaw and burner moving means operable by said timing means for moving said jaw means and said burner means from the remainder of said retained exhaust tubulation to effect the complete severing of said retained exhaust tubulation from said hermetic tip portion, and said burner means continuing to heat the severed tip portion of said tubulation proximate said arc tube body to effect a fire polishing thereof and then operable to open said jaw means to release the now sealed arc tube.