Patent GB-433501-A (GB)
Title: Improvements in or relating to machines for making stems for electric incandescent lamps, thermionic valves and the like
IPC: H01J9/32
Filed: 1934-09-17
Abstract: 433,501. Thermionic valves. HOFMANN & CO., A., 635, 15th Street, West New York, New Jersey, U.S.A.-(Assignees of Trutner, D. G. ; North Arlington, New Jersey, U.S.A.) Sept. 17, 1934, No. 26678. Convention date, Sept. 21, 1933. [Class 39 (i)] [See also Groups XI and II] A machine for making stems for electric incandescent lamps, thermionic valves, &c. is provided with a series of travelling heads each having chucks for holding the flare, exhaust pipe and cane in axial position, mechanism for feeding the components to their chucks, and means to heat and unite the components when in axial position, each of the heads having one of its chucks shiftable bodily from its axial position to an outer position for delivery of the completed lamp stem after its release from the other chucks of the head. The components are fed laterally from the front into their chucks, followed by a vertical adjustment to ensure that the flare surrounds the other parts. The absence of a flare in a chuck prevents the feeding of the other components to that head. The exhausting-tube chuck shifts bodily from an axial position, receives the tube, and holds it to one side until the tube end has been heated and bent, then swings it into the flare before the axial adjustment. The machine comprises a circular frame table 61, Fig. 4, provided at its centre with a vertical sleeve 62 supporting an interior sleeve 63 which guides a vertically reciprocating operating- rod 625. Above the table 61 a rotary turret 67 supports the series of twenty-five heads and is driven by studs 70 on an annular web 68 engaging a cam surface on a wheel 72 mounted on a driving shaft 73. Gas and air are supplied by ducts 90, 91 respectively which extend more than half way around the machine and are provided at intervals with valves and flexible connectors leading to an arched duct 99 connected to the nozzles or burners. The heads pause at each of the stations a to y, Fig. 1. At a the flare is fed into its chuck, with the skirt end uppermost. The cane is fed at c, leading-in wires at d, e or f, and the exhausting-tube at g. The exhausting-tube is held offset from the axis and heated during its travel from g to h, Fig. 2 (not shown), in order that its lower end may be bent slightly. Between h and j, Fig. 2 (not shown), the tube is swung into the axial position, and the components are readjusted axially by sliding the flare downwardly at i, Fig. 2 (not shown), and the tube D at j, Fig. 2 (not shown), the parts then being as shown in Fig. 35. Fig. 6 shows one of the working heads of the machine, comprising right and left hollow columns 103, 104 with horizontal slideways 106, 107 at their upper ends. The chucks carried by the head, with the exception of the flare chuck, are all swingable laterally between axial and outer positions. The jaws 113, 114 of the flare chuck are movable in guides 106, 107, the left jaw 114, Fig. 7, being slotted, while the right jaw 113 presents a deep narrow engaging surface. The flare chuck jaws are opened by the rocking of a shaft 120 within column 103 under the action of a cam-operated lever 122 carrying a roller 123. The exhausting-tube chuck comprises relatively fixed and movable jaws 125, 126, Fig. 6, at the upper end of a rocking sleeve 127, on a carriage 128 which can be swung to and from the axial position of the head. The jaw 125 is fixed to the carriage 128 while the jaw 126 is mounted at the end of a rocking lever 130 connected by a link to the top of a rod 132 slidable in a sleeve 127 within the column 104. Means are provided for adjusting the sleeve 127 and carriage 128 for different lengths of exhausting-tube, and a collar 140 formed on the sleeve has an extension 141 carrying a screw 142 which bears on a bracket 111 to determine the axial position of the chuck. Flare -feeding mechanism.-The device for feeding the flares into the machine from a hopper 200, Fig. 16, comprises a pick-up wheel 201 which is rotated intermittently in one direction. The wheel is provided inside with tracks 217 which engage the flare skirts and pick up the flares with their shanks hanging between the tracks, a nozzle 226 being provided to deliver air for adjusting the positions of flares on the tracks. The flares slide down the tracks 217 on to fixed tracks 227 on a shoot 202, from whence they slide downwardly to a block 233 on which is pivoted a normally closed gate 234 on a shaft provided with an opening-finger 236. This finger is controlled by a flare-transferring device comprising lower and upper segments 238, 239, of which the former has a recess 240, Fig. 17, to engage the shank of the flare, and a horn or separator entering behind the flare. The segments are mounted on a vertical shaft 243 which is oscillated by a horizontal pinion 244 at its upper end engaging a rack bar 246. To prevent the feeding of flares from the hopper when the shoot 202 is full of flares awaiting transfer to the machine, a feeler rod 290 mounted above the flares A in the shoot controls the vertical oscillation of a rod 287 which controls a clutch on a shaft carrying gear wheels to drive the pick-up wheel, the gears being disconnected when the feeler bears on a flare in the shoot 202. Cane-feeding mechanism.-The canes are fed at station c from an inclined hopper 300, Fig. 1, into the peripheral slots of a rotary feeding-wheel which brings successive canes to its lowermost position. A gripper 302 engages the cane, picks it from the wheel, and swings it across and laterally into the cane chuck. A feeler 342 is provided to detect the presence of a flare in the head and, through a link connection, stop the cane feeding-wheel if a flare is absent. Feeding leading-in wires.-Leading-in wires are extracted manually from a cup on a bracket on the front of the machine table between stations e and f, two wires for each head being inserted between the open chuck jaws into contact with gauge strips. Exhausting-tube feeding mechanism.-Exhausting-tubes are supplied from an inclined hopper 430, Fig. 24, to an inclined feed wheel 431 from which they are transferred to a gripper device 432, comprising jaws 510, 512, which sets them upright and places them in the tube chuck at station g. The exhausting tubes are subsequently bent at their lower ends during their travel, being first levelled, and then heated by burners before meeting a bending-plate which acts on their lower end. Pinching-mechanism.-Between stations i and r, Fig. 2 (not shown), the flare and cane are heated bv rows of front and rear burners before their arrival at the pinching-mechanism, which is also provided with burners 607, 608, Fig. 4, and co-operating pinching-jaws 611, 612 on sliding shanks 613. Links 615 pivoted to the shanks 613 connect them, through a series of links and arms 616-618 to an actuating lever 619 which is linked to a rocking-lever 621 operated by a vertically reciprocating rod 625. Perforating - mechanism.-A perforation is formed at the joint between the flare and exhausting-tube by blowing air down the latter at station s, a burner 638, Fig. 1, being provided to soften the junction while the upper end of the exhausting-tube is brought beneath a pivoted coupling block which connects it to an air delivery device. The coupling block is normally inclined, and is raised to a horizontal position by the upper end of the exhausting-tube riding under it, the end of the tube then being located within a recess in 'the coupling block during a position of rest of the machine. A jet of cold air is blown into the flare to prevent its collapse during heating. The stem is next moved to station t where a burner is directed towards the perforation to soften and smooth the glass. Air nozzles subsequently direct air upon the stem before its removal from the machine.