Patent GB-490864-A (GB)
Title: Improvements in and relating to machines for sealing incandescent electric lamps and similar articles
IPC: H01J5/24
Filed: 1937-03-25
Abstract: 490,864. Making electric incandescent lamps. BRITISH THOMSON - HOUSTON CO., Ltd. March 25, 1937, No. 8849. Convention date, March 26, 1936. [Class 39 (ii)] A sealing machine for electric lamps and the like comprises a carrier provided with a series of heads each comprising a bulb holder and a mount holder arranged to hold a bulb and a mount in axial alignment, means for indexing the carrier, a stop disposed adjacent the path of movement of the heads for positioning a bulb and means for lifting the bulb vertically to engage the stop, means for moving the mount axially to cause it to enter the bulb a predetermined distance, and heating means for fusing the neck of the bulb to a portion of the mount. The lamps for which the machine is adapted comprise a mount 10, Fig. 1, consisting of a glass tube 11 with a pair of filament-supporting wires 12 fused in the end thereof and extending substantially axially of the tube, and a pair of leading-in wires 14 embedded in the tube 11 on opposite sides thereof and, preferably, also embedded in a bulbous portion 15 near the end of the tube. This mount is to be sealed into a cylindrical bulb 16, with the bulbous portion 15 of the mount fused to the upper end of the bulb. The machine is preferably of the rotating turret type, indexed intermittently in a counterclockwise direction to advance the heads through a series of working positions. At the loading-position, a bulb 16 is placed between a pair of jaws 19, 20, Figs. 3 and 4, which are pivoted on pins 22<1>, 23 at their lower ends and held open by a spring 24 located between them, a stud 25 being provided on jaw 19 to register the bottom of the bulb. These jaws are closed at the third position of the head by the downward movement of a surrounding sleeve 45 which is pulled downwardly by a spring 47 when a lever 35 on the outside of the sleeve strikes a stop adjacent to the path of the head, thereby turning a pivoted pin 44 until flat portions 46 thereof become uppermost and permit the sleeve to be pulled down. A bevelled ring 48 around the top of the sleeve is thus brought to bear against protuberances 48<1> on the jaws 19, 20, causing the jaws to close. The support for the jaws consists of a spindle 30 mounted in a bushing 31 which is rotatably mounted in the turret 17 and carries a gearwheel 113 at its lower end which engages driving means to rotate the head when in the sealing position. A collar 33 at the top end of the bush 31 supports a post 32 which carries a block 26 forming a support for the mountcarrying jaws 21, 22 ; these jaws are pivoted in the block 26 and normally held together by a spring 29 connected between them, the means for opening them comprising a pin 27 with an enlarged portion which forces them apart when a cross-arm 28 is rotated by the operator. To ensure that all portions of the filamentsupporting structure of the mount will be carried into the bulb without injury, a guide consisting of a funnel formed in two halves is provided at a subsequent position of the head, each half of the funnel being mounted on a lever carried by a common pivot on a sliding support. When the funnel halves are together and located above the bulb, the bulb carrier is raised by the upward movement of a rod 69 located below the end of the spindle 30, and the lower end of the funnel enters the upper end of the bulb. The funnel and bulb are now moved simultaneously until the filament and its supports are well within the bulb, whereupon the funnel is lifted out of the bulb, its two portions are opened outwardly and the bulb is raised further to approximately the sealing position. At a further position of the head, the bulb and mount are positioned by the mechanism shown in Fig. 6, comprising a positioning finger 77 which is carried on a slide 78 and brought just above the upper end of the bulb, whereupon a finger 89, pivoted on the slide 78, is swung and lifted to engage the lower end of the bulb and lift it until its neck strikes the finger 77. A lever 99 is then swung so that a bolt 98 at its end engages the upper end of the exhausting tube 11 and pushes the mount down into its correct position in the bulb 16. The parts, thus in contact, are indexed to the next position of the head, where the gear 113 engages means for revolving the head while oppositely directed flames are applied to the parts to be sealed. Similar burners are preferably arranged at the next eight positions of the head. At one of these positions, air is blown through the tube 11 to expand the seal, and the lamp is subsequently allowed to cool before being released from the machine.