Patent GB-413206-A (GB)
Title: Improvements in the manufacture of electric incandescent lamps, thermionic valves, electric discharge devices and the like
IPC: H01K3/18
Filed: 1933-12-18
Abstract: 413,206. Thermionic valves. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London.-(Assignees of Patent-Treuhand Ges. f³r Elektrische Gliihlampen; 11, Ehrenbergstrasse, Berlin.) Dec. 18, 1933, No. 35613. Convention date, Dec. 17, 1932. [Class 39 (i).] Caps are secured to electric incandescent lamps, electric discharge devices and the like by placing the cap thereon in its normal position and injecting cement into the cap through one or more apertures provided therein. The operation is performed mechanically in a capping- machine comprising an intermittently rotating carrier which carries the lamps beneath a container from which a cement is ejected through a nozzle, a jet of air being subsequently blown through a separate nozzle to distribute the cement within the cap, and a mechanical brush being also provided to clean the cement-ejecting nozzle. Means are provided for preventing operation of the cement-ejecting mechanism if a lamp arrives at the filling position without a cap. The lamp bulbs 4, Fig. 1, are placed in cupped apertures 3 at the upper ends of tubular sockets 2 which are mounted around the periphery of the rotating carrier 1, each tubular socket being adjacent to a bracket 12 formed with an aperture to engage the upper end of the lamp cap to hold it vertically while the bulb is retained in the socket by the suction of a vacuum pump connected to its lower end. The cement container 14 is carried by a pair of lateral arms 30 on a sliding member 31 which is reciprocated within a vertical pillar 32 by a shaft 34 connected by a link 47 to a lever 48 adapted to be lifted by a cam 52 against the tension of a spring 50. The bottom 17 of the cement container 14 is tapered and provided with a removable nozzle 19 held in position by a nut 20. A hollow tube 21 movable vertically within the cement container and through the cover 15 is closed at its bottom end by a plug 22 which acts as a piston and is also formed with an axial bore to receive a closely fitting needle 24 at the lower end of vertically movable rod 23 within the tube 21. The piston tube 21 is actuated by a lever 36 provided with a forked end engaging rollers within a peripheral groove 39 in a bush 40 on the tube, the movement of the lever 36 being controlled by the shaft 34 to which it is secured. Movement of the rod 23 and needle 24 relatively to the piston tube 21 is controlled by a forked lever 43 pivoted on a bracket 42 and connected to lever 36 by a link 46. The arrangement is such that when a lamp arrives at the cement injecting position beneath the nozzle 19, the rod 34 moves downwardly and, at the beginning of this movement, the slide 31 and cement container also descend, until arrested by a screw 55 on the slide, the nozzle 19 now being within the central aperture in the base plate 7 of the lamp cap. Continued movement of shaft 34 causes the piston to move downwardly into the part 18 of the cement container and eject cement through the nozzle, this action being accompanied by the upward pivoting of lever 43 and the lifting of the rod 23 and needle 24 within the cement container. The outer surface of the nozzle 19 may be cleaned by a brush 92 on an arm 91 which is rocked to and fro by supporting it on a sleeve 87 formed with a curved slot to receive a bolt 90 on the shaft 34 on which the sleeve is mounted, means being provided to prevent longitudinal movement of the sleeve. The lamp, with cap filled with cement, is carried to the next working position, where a stationary nozzle directs a stream of compressed air into the aperture of the cap to distribute the cement therein. Subsequently the lamp is carried to a heating position where the cement is hardened, after which a milling device removes surplus cement from the cap. To ensure that no cement will be ejected when there is no lamp in position, an automatic control device is provided, comprising a solenoid 62 with a core 63 which, in the absence of a lamp in the carrier, is pushed out by a spring 64 into the path of the rocking-lever 48 operating the cement-ejecting devices. The solenoid is connected across spaced contacts 58, 59, of which the former is mounted on a spring-biassed member 57 adapted to be pushed upwardly by a lamp cap entering the working position, thereby closing the circuit to withdraw the core 63.