GB570803A - Improvements in machines for mounting filaments of incandescent electric lamps and the like - Google Patents

Abstract

570,803. Incandescent lamp making. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 20, 1942, No. 16415. Convention date Nov. 26, 1941. [Class 39 (ii)] A machine for attaching filaments to mounts and extracting defective products has an intermittently moving carrier as in Specification 390,870, with heads each adapted to hold a stem with two metal leads, and a number of stations into which each head is successively indexed. At station A jaws 33, 34 (Fig. 3) close upon the leads so that fingers 31, 32 gather up and position them while blades 35, 45 trim their ends and a roller 46 is moved across them to make a transverse V-grove in each (Fig. 5a). At station B filament material held between blocks 59, 60 (Fig. 4), and projecting through a hole in a guide 61 is gripped and drawn forward by jaws 62, 63 carried by a slide 64 on a carriage 56. The carriage is then advanced to the mount so that a spring pressed slide 105 presses the leads against an abutment 107 and the filament material is placed in the grooves in the leads. Jaws 101, 102 then close and cause a tool 104 (Fig. 5b) to enter the grooves and press the material of the leads over the filament to secure it, while two disc cutters 122, 123 with abutting faces are rotated in opposite directions to cut off the filament. The jaws 62, 63 may be prevented from feeding filament material by a solenoid operated member controlled by a manual switch, or by a movable finger at the preceding station which may operate in respect of a defective stem. At station C a finger 163 (Fig. 10) is pressed between the converging leads to put tension on the joints and render a partly defective construction wholly so. At station D one of the holders 187 on a conveyor chain is advanced into engagement with the stem and at the same time spring contacts 179, 180 (Figs. 1 and 11) are engaged with the leads and a switch 196 closes automatically the circuit of an indicating lamp and of solenoids 197, 198. These circuits pass through a contact 191 of a relay which is energized by current through the filament and therefore opened only if the filament connections are intact and of a predetermined low resistance. In other cases the lamp lights, the solenoid 197 actuates the release of the jaw holding the mount in the head and the solenoid 198 causes the conveyor chain to be moved forward on its next advance carrying the defective mount.