GB720422A - Improvements in and relating to the manufacture of electric lamps - Google Patents

Abstract

720,422. Dynamo - electric apparatus. BRITISH THOMSON-HOUSTON CO., Ltd. June 26, 1952 [June 30, 1951], No. 16113/52. Class 35. [Also in Group XI] Apparatus for threading a leading-in wire into a vertical perforation in the end of a lamp cap comprises means for holding a lamp bulb upright with the leading-in wire substantially vertical, means for locating the cap in alignment over the bulb, and means for agitating the cap both vertically and laterally while thus located in order to provide repeated opportunities for the wire to enter the perforation. The apparatus is preferably located at one of the work-stations adjacent to an indexing- conveyer of the endless-chain type provided with a series of pairs of bulb-holding jaws, each of which holds a bulb vertically with the neck uppermost (see Group XI). The cap is of the kind comprising a screw-threaded metal shell with its upper end closed by a web of insulating material such as glass with a metal eyelet located within it to form a central end contact. Below the eyelet the glass web is recessed to a conical shape to facilitate the threading of the leading-wire through the aperture. In one arrangement, Fig. 6, the agitation of the cap within a threading-tube is effected by magnetic induction, the threading- tube being made in the form of a soft iron yoke 91 with three inwardly facing wire-wound poles 88-90 to which 3-phase A.C. is applied, thereby developing a rotating magnetic field and generating eddy currents within the cap, so that it is caused to vibrate and rotate; its rate of descent is also retarded. In a modification, Fig. 7, a threading tube 99 is resiliently mounted on a base by means of flexible spring fingers 100, 101 and an armature 103 attached to the threading tube is vibrated by an electromagnet 102, the system being arranged to be mechanically resonant at a frequency close to that of the energizing current of the magnet. The threading tube is slotted vertically at equidistant intervals and flexible snubber wires or springs 105 are located in the slots, their upper ends being fixed to the interior of the tube immediately above the slots.