Patent GB-190610021-A (GB)
Title: Improvements in Machines for Making Stems for Incandescent Electric Lamps
Filed: 1906-04-30
Granted: 1907-03-21
Abstract: 10,021. British Thomson-Houston Co., [General Electric Co.]. April 30. Incandescent lamps. -A machine for making double-tube stems with the leading-in wires and the anchor wires scaled in is shown in partsectional elevation in Fig. 1. The tubes forming each stem are concentric and are united at their inner ends, the inner tube serving for the exhaustion and sealing of the lamp. A table 1 carries a standard 2 on which are independently mounted a sleeve 5, driven by a belt and pulley 6 and attached to a sprocket-wheel 7, and a rotary frame 8 comprising arms in which are formed bearings for shafts 9. A spring arm 65 acts on projections on the frame so as to arrest it in definite positions. The shafts 9 are enlarged at their lower ends, and above the enlargements are mounted loose sprocket-wheels 10. A chain passes over the sprocket-wheels 10, 7 and is kept taut by a wheel on a spring arm. Each shaft is provided with a clutch consisting of a pin 16, passing through the enlargement and normally entering a hole in the wheel 10, and of a spring-urged lever 17 pivoted to the pin. In two positions of the frame, inclined stops on posts 45 rock the levers and prevent rotation of the shafts. In a third position, the shaft may be arrested when required by means of a stop on a movable rod 46 which can be raised by a lever 51, a rod 50, and a pedal. The lever when thus rocked also actuates a valve 43, thereby diminishing the supply of gas and air to blowpipe burners 4, 42 which are mounted respectively on the standards 2, 40. Each shaft 9 carries a frame consisting of a cross-head 20, uprights 21, and a plate 22. Sliding pieces 25, Fig. 5, for gripping the outer glass tube are mounted on the plate 22, and have pins 26 which enter eccentric slots in a disk 23. This disk fits in a groove in the wall of a circular aperture in the plate, and is acted on by a spring 28 and provided with a handle 27. The outer glass tube rests on a ridge on an arm 30, Fig. 1, and the leading-in wires rest on flats beside the ridge. The flared inner tube is carried by a shouldered adjustable rod 31 which passes through the centre of the shaft and is provided with a knob at its lower end and with an arm 35 sliding on one of the uprights 21. On the rod is a sleeve connected to it by a pin and longitudinal groove and provided with a handle. An anchor wire is inserted in a socket in the sleeve and in line with a hole in the arm 30. The tubes and wires having been inserted while the shaft is arrested by one of the fixed stops, the frame is turned so as to bring the tubes under the action of a preliminary heater 67. In the next position, the tubes are fused together at their lower ends by the blowpipes 4, 42. The pedal is then operated and the sleeve on the rod 31 is raised so as to push the anchor wire into the soft glass. Next, the glass is squeezed up round the leading-in wires by means of pincers 55 carried by a hinged arm 54 and actuated by a button 56 and toggle-links. To round off the seal, a nozzle 62 of rubber or the like attached to a spring-urged tube 60, which can slide in a fixed tube 58<1>, is brought against the end of the outer glass tube. When it is in this position, the tube 60 is in communication with a compressed-air tube 58..