Patent GB-672494-A (GB)
Title: Apparatus for inverting tubular lamp bulbs in sealing machines
IPC: H01J5/24
Filed: 1950-06-27
Abstract: 672,494. Making tubular electric lamps. SYLVANIA ELECTRIC PRODUCTS, Inc. June 27, 1950 [June 30, 1949], No. 16069/50. Class 39(ii) In a machine provided with indexing means for advancing a row of symmetrically positioned lamp tubes successively to work stations at which filament mounts are sealed upon the ends of the tubes, automatic means are provided for inverting the tubes so that both ends can be sealed in an uninterrupted sequence of working steps. The inverting mechanism comprises a tube holder 24 mounted on a rotatable carrier 10 which is mounted at the upper end of a jib-like unit 6 movable, in the radial direction of a turret 1, towards the advancing tubes 4 and, after a tube has been gripped by automatic closure of a gripper arm 26, Fig. 3, the unit 6 is moved outwardly from the turret, whereupon a shaft 22 on which the tube holder is mounted is rotated through 180 degrees and the unit 6 swung inwardly again, towards the turret. The transverse distance between the position of the grippers before and after rotation through 180 degrees is equal to the pitch distance between the heads 2 on the intermittently moving turret, and the movements are so synchronized that the inverted tube is repositioned to be replaced in the head from which it was removed. The carrier unit 6 is on a two-part mounting, namely a main lower part 8 pivoted at 7 to a fixed base and a secondary upper part 9 which slides vertically upon rods 9x on the part 8. The unit 6, which is offset angularly, and the parts 8, 9 are swung bodily about the pivot 7 by a cam 11, Fig. 2, mounted on a camshaft 12 and engaging a follower 14 projecting inwardly from the frame part 8. Vertical movement is imparted to the upper part 9 of the unit by a cam-operated lever arm 16 which is bent upon itself at its end 18 to form an elongated loop which engages a roller 19 carried on a transverse shaft at the lower end of the part 9, this arrangement permitting vertical movement of the part 9 simultaneously with outward and inward rocking of the unit 6. The cam 21 which operates the lever arm 16 is contoured to maintain the part 9 in its upper position throughout most of its cycle and lowers it for a short period when an inverted tube is re-delivered and another bulb picked up. The tube carrier 10 comprises a casing 23 in which is journalled the shaft 22 carrying a circular hub 30 supporting the tube holder 24. Two notches 31; Fig. 4, spaced 180 degrees apart in the periphery of the hub 30, receive a spring- actuated detent which successively locks the tube holder at half-revolution positions. Rotation of the holder when in its outer position away from the turret is effected by two flexible cables 33, Fig. 4, each with an end secured to a drum 34 on the shaft 22, the opposite end of one cable being secured to a tensioned spring 35 and of the other to a cam-controlled rocking-arm 36, Fig. 1. A pawl and ratchet connection between the drum 34 and shaft 22 causes the drum to rotate the shaft in one direction and permits the return of the drum freely in other direction. The tube holder 24 is provided with a pair of parallel grooves 25, Fig. 3, co-operating with oppositely directed spring-pressed fingers 26 pivoted to a common pivot in a transverse slide 28. An actuating pin 29, Figs. 3 and 4, connected to the slide 2 is engaged by one arm of a lever 45 connected by a link 46 to a cam-actuated lever whereby the slide 28 is moved to actuate the fingers 26 alternately to clamp one and release the other when the part 9 of the carrier unit is in its lower position.