GB652609A - Lamp sealing apparatus - Google Patents

Abstract

652,609. Making electric lamps; gas burners. SYLVANIA ELECTRIC PRODUCTS, Inc. Aug. 7, 1947, No. 21694. Convention date, June 28, 1940. [Classes 39(ii) and 75(i)] In apparatus for sealing off a vertically arranged exhaust tube of an electric lamp having means to impart a reciprocating horizontal stroke to a pair of centrally notched semi-conical burner shields and to a pair of sealing-off burners which direct a flame into the shields, variations in the location of the exhaust tube in the direction of the stroke are accommodated by automatic variation of the length of the stroke, e.g. by means of a lost-motion connection and a spring centring means. As applied to an exhausting machine wherein the exhaust tube 2 of an electric discharge lamp is pushed upwardly into a rubber connection 23, the lamp being indexed through suitable exhausting stages to the sealing station shown, a pair of spring- closed splayed end jaws 4 are provided, each carrying a burner 16 or 17 and a semiconical shield 18 or 19, and pivoted at 57 to a plate 13 mounted on a pin 29 in a saddle 28 integral with a member 59 rotatable on a stud 5 projecting from a slide 45. Cam actuation of a rod 40, connected by a link 44 and a spring-loaded slotted lever 43 to the slide, projects the whole assembly towards the exhaust tube 2, an upper slotted baffle plate 3 engaging the tube 2 and serving to adjust the plate 13 about the stud 5, while horizontal slots engaged by the pin 29 in the saddle 28 allow the notches 8 in the shields to adjust themselves in the direction of projection, on to the tube 2; a fork 25 on the slide 45 serves with the spring 26 to steady the lamp body. Cam actuation of a rod 41 then lowers the assembly (the slot in the lever 43 now being vertical), so that the shields 18, 19 enter the lamp stem flare, slight rotation of the plate 13 about the pin 29 being allowed within the limits of stops 24, 54. When the flames from the burners 16, 17 have softened the tube 2, cam actuation of the rod 41 lowers the assembly further so that the jaws 4 press the lamp down to seal and sever the tube 2 within the flared lamp stem, the grip of the chuck 27 being not so strong as to prevent this. The rod 41 is then moved upwards slightly so that the flames from the burners 16, 17 may anneal the tip of the tube 2. Further cam actuation of the rods 40, 41 returns the assembly to starting position with the stud 12 against the stop spring 51, and the machine is indexed.