Patent GB-569293-A (GB)
Title: Improvements in and relating to glass working apparatus and method
IPC: C03B23/26
Filed: 1943-11-22
Abstract: 569,293. Glass - -working machines. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 22, 1943, No. 19495. Convention date, Nov. 21, 1942. [Class 56] Relates to an apparatus for severing a portion of the neck of a miniature lamp bulb and for forming an indentation in the bulb wall adjacent its tip, for engagement by a leading- in wire to locate the filament accurately as described in Specification 433,033, [Group XI]. The apparatus comprises two turrets A, B, Fig. 1, rotating about vertical axes. the severing taking place at one of the stations of the turret A and-the indentation being formed at one of the stations of the turret B, transfer between the turrets being effected by a transfer wheel T rotating about a horizontal axis in the plane of the terrets A, B. In Fig. 1 the turrets and transfer wheel rotate counterclockwise. The turret A is provided with sixteen constantly-rotated holders and the turret is intermittently rotated through the sixteen stations. At station A1 the bulbs are fed from an inclined shoot 73 by an arrangement generally similar to that described in Specification 212,412, [Class 117], the bulbs being released one at a time and travelling down the shoot in a vertical position, bulb uppermost, and being diverted at the base of the shoot into a horizontal position, bulb foremost, in which position each bulb is drawn by suction into the holder at station A1 with its neck projecting horizontally therefrom. The holders are interchangeable to accommodate bulbs of different sizes. The bulbs are retained in the holders by suction to a point just in front of station A13 the suction is replaced by compressed air to discharge the bulb into the first station of the transfer wheel T. Stations A2-A5 are idle, whilst at station A6 the bulb is accurately aligned, by the engagement of its projecting stem with a bar 107, in a horizontal position and the portion of the protruding neck which is to be severed is heated at station A7. The neck is severed at station A8 by the engagement therewith of a chilled crack-off wheel which at all times other than when it is required for the actual severing is immersed in a bath 115 of cooling liquid. The cut edge of the neck is further heated to glaze and smooth the same at stations A9, A10 and the bulb then passes idle station All to station A12 where it is realigned by a bar 158 preparatory to discharge at station A13. A blast of air is passed through the holders at stations A14, A15 to ensure the discharge of any bulb which may inadvertently not have been discharged at station A13 and to remove any glass fragments. The transfer wheel T is provided with twelve holders, the bulb being received at station T1 and held by suction until discharged by compressed air and gravity at station T4 into one of the holders of the turret B, the remainder of the stations of the transfer wheel being idle. The turrets and transfer wheel are all rotated step-by-step in timed relationship. The turret B comprises twenty-four self-closing chucks which are held open at and between stations B19 and B1 by the engagement of their cam-levers 293 with a stationary cam-track 297. A bulb drops from the transfer wheel, bulb downwards, into the chuck at station B1 which closes about the bulb as the chuck is indexed through stations B2- B4. At station B5 the bulb is positively seated and accurately aligned vertically in the chuck by a yielding fluid-pressure operated spring plunger. At stations B6-B15 the downwardly-facing tip portion of the bulb is exteriorly heated by the combustion of gases supplied by pipes 324 whilst at station B16 a mechanically-operated pointed plunger descends through the chuck and bulb to form an indentation in the inner surface of the tip of the bulb and an outwardly-projecting protuberance. During the punching the heating of the tip is continued and at the next station the tip is further heated to remove internal strains in, and to anneal, the tip. The bulb then passes through idle station B18 to the discharge station B19 where the chuck is opened and the bulb is discharged by being ejected upwardly into a pneumatic shoot 362, the ejecting mechanism being yieldingly linked mechanically to the mechanism which reciprocates the punching plunger. At stations B20, B21 jets of compressed air clear the chuck of any bulb which has escaped ejection at station B19 and any broken fragments, after which the turret is indexed through idle stations B22-B24 to the feeding station 131 in readiness for receiving another bulb.