Patent GB-475688-A (GB)
Title: Improvements in and relating to apparatus for sealing metal to glass
IPC: H01J5/26
Filed: 1936-10-12
Abstract: 475,688. Sealing metal to glass by heat. BRITISH THOMSON-HOUSTON CO., Ltd. Oct. 12, 1936, No. 27648. Convention date, Oct. 11, 1935. [Class 36] A machine for sealing a terminal member, such as a metal disc, directly to an end of a glass bulb comprises a turret provided with a series of heads each comprising a vertically disposed support for holding a metal disc on its upper end, jaws for holding a glass bulb in a substantially vertical position with its lower end abutting against the upper surface of the disc, means for pressing the bulb downwardly against the disc, and a burner located beneath the upper end of the support for heating the disc to fuse and seal thereto the portion of the bulb in contact therewith. A stop is preferably provided to limit automatically the downward movement of the bulb during the fusion of its end. The heads 10 are spaced equidistantly around a turret 11, and are preferably loaded and unloaded at one and the same position, the loading consisting in placing a metal disc 12 upon a spindle 13, and a bulb 14, which in the example is tubular, in jaws 15, 16. The disc 12 is of the type described in Specification 452,191 and has an indented portion 121 which fits over the end of the spindle 13. An exhausting-tube 17, previously sealed to the disc 12 extends downwardly into the spindle 13, which is mounted in a hollow post 18. The jaws 15, 16, each carrying V-notched blocks 20, are rotatably mounted on pins 22, 23 on a bracket 24, and are separated to permit insertion of the bulb by pressing manually upon one end 26 of a lever 21 which turns about a pin 27 in the bracket 24 and pulls a wedge 28 from between rollers 29, 30 on the rear ends of the jaws, which are then pulled open by a spring 31 connected between them. After the bulb 14 has been placed in the jaws, with its lower end abutting against the disc 12, a weighted tube 38 is swung over and on to a disc 39 on the upper end of the bulb causing the lower end to be pressed firmly against the disc. The jaws are then closed by the wedge 28 which is again forced between the rollers 29, 30 by a spring 33 pulling the lever 21 rearwardly. At the second position of the head 10 a combustible gas mixture is ignited at a burner 52 by a stationary flame (not shown), the flame from the burner being directed against the disc 12, so that only that part of the glass in contact therewith is fused. The burner 52 comprises a hollow body 53 surrounding the upper end of the spindle 13, and a plate 54 which closes off the interior of the burner except for a space below the disc 12 where the flame is produced. The gas is conducted to the burner through a series of pipes and elbows 56 ..59 connected to a passage 55 in the lower half 37 of a rotary valve, the upper half of which has an arcuate passage 65 to conduct the gas mixture from a pipe 66 to the passage 55 as the head passes through the three positions following the loading position. The heated parts are allowed to cool as they pass through the next two positions of the head. The lower end of the bulb is preferably provided with a flange 67 of smaller diameter than the remainder of the bulb, to melt down on to the upper surface of the disc. When the flange is completely melted a stop-screw 68 on a weighted arm 40 carrying the tube 38 strikes a stationary collar 69 to prevent further vertical movement of the bulb. Specification 464,744 also is referred to.