Patent GB-824231-A (GB)
Title: Improvements in or relating to the manufacture of glass envelopes
Inventor: HAINES ERNEST MARTIN
IPC: C03B23/217
Filed: 1956-10-03
Abstract: 824,231. Glass manufacture. GENERAL ELECTRIC CO. Ltd. Oct. 3, 1957 L 'Oct. 3, 1956], No. 30181 /56. Class 56. In the manufacture of a glass envelope, such as a cathode ray tube, having an end portion with a rim upstanding from a plane or dished base and a hollow body portion with a peripheral edge substantially matching the rim to which it is to be sealed, the end and body portions are preheated at a separate stage, the heated portions engaged with transfer means provided with positioning means which adjust the portions to set positions at which they are held in alignment and can be brought together with edges abutting by movement along a path of relative approach, the transfer means transported to a sealing stage at which are located holders for the end and body portions, the end and body portions, still held in alignment, engaged with the holders and released from the transfer means, the holders then being moved along the path of relative approach to bring the peripheral edges together in alignment for sealing, the portions being heated around the edges to effect the sealing of the portions together. The end and body portions are heated while resting with edges facing inwardly on carriers 14 inclined at about 45 degrees to the vertical. The transfer means 11 engages the portions 17 by means of abutment members 16 on plates 15 hinged at 40 to a common support 82 carried by guide rails 13, the plates 15 being pivoted out to engage the body and end portions 7, 8 and then pivoted back to the position shown with the peripheral edges 9, 10 of the portions 7, 8 in alignment. The transfer means 11 is then moved along the rails 13 to a position between opposed rotatable chucks 2, 3 carried by carriages 4, 5 slidably mounted on a bed plate 6 for independent movement along a path parallel to the axis of rotation of the chucks. The chucks 2, 3 are constructed as described in copending Specification 824,232 and engage the portions 7, 8 in aligned posi. tions. The portions 7, 8 are released by the abutments 15, the chucks being moved apart so that the transfer means can return along the rails 13, and the chucks 2, 3 are then moved inwardly to bring the edges 9, 10 together for for sealing. After sealing, the envelope may be annealed while still carried by the chucks or transferred to an annealing stage, leaving the chucks free for further sealing operations. The transfer means, shown in detail in Figs. 3 and 4, comprises at each side a base plate 15 on which two movable supports 19 are pivoted at 18, each carrying two abutment members 16, pivoting of the supports 19 moving the abutment members 16 towards or away from the centre of the plate 15. Midway between the pivots 18, a raised platform 20 supports a control cylinder 21 with two air operated pistons 22 each on a rod 23 extending outwards through a packing 24 and carrying a metal collar 27. A guide rod 25, coaxial with rod 23, at the other side of collar 27 is free to slide in a guide 26 on the platform 20. Each support 19 is connected by a rod 29 and ball and socket joints 28, 30 to each collar 27 so that as pistons 22 are moved outwardly by compressed air through pipe 31, the supports 19 are rotated inwardly by the same amount for the abutment members 16 to engage the body or end portion 7 or 8. Compressed air is supplied through pipe 32 to move the pistons inwardly to release the parts, the supports moving outwardly to engage fixed studs 42. Each abutment member 16, formed of superimposed laminations of asbestos, is approximately spherical and is rotatably mounted on a pivot 33 carried by a circular cradle 34 on a mounting 35 secured to the support 19 with a packing member 36 interposed so that the members 16 bear against the end or body portion at a predetermined distance from the edge 9 or 10 which rests against four cylindrical rollers 37 freely mounted on spindles 38 carried by supports 39 adjacent each corner of the base plate 15. In the preheating stage, carriers for a number of end and body portions may be arranged to bring each pair in turn to the position of carriers 14.