Patent GB-190908351-A (GB)
Title: Improvements in and relating to Electric Incandescent Lamp Making Machines.
IPC: H01J5/24
Filed: 1909-04-06
Granted: 1910-02-10
Abstract: 8351. British Thomson-Houston Co., [General Electric Co.]. April 6. Making.-An automatic apparatus comprises a machine for shortening and flaring bulb necks, a machine for sealing stems bearing filaments into them, and a transfer mechanism for removing the shortened bulbs and positioning them for sealing-in. In the construction shown, the shortening and flaring machine, Fig. 6, consists of a rotary annular support 26 in which a single bulb is placed by band above a ring of burners 29, which can be adjusted vertically. The supply of gas to the burners 29 is reduced by a cam-operated valve when the excess of bulb neck has been fused off, and compressed air to blow off the fused neck is then admitted to the bulb through a cap 32 on an arm 33. The bulb neck is flared by means of two pincer-like refractory arms 27, having semicircular ends that are brought together around the neck by a pneumatic device, and act as a mould during the blowing-off ; the ragged edge is then smoothed by an arm 28, raised into contact with it pneumatically. The shaped bulb is transferred to the sealing-in machine by the arm 33, Figs. 4 and 6, which is raised and lowered by cam-operated rack gear 40, Fig. 4, and is rocked by a sleeve 35 and a camoperated crank 36. Bulb-gripping arms 47 at the end of the transferring-arm 33 are operated by a toggle 48, which is automatically straightened to grip a bulb as shown in Fig. 6, and broken to release it on the sealing-in machine. The sealing- in machine comprises an intermittently-rotating spider 18, Fig. 4, having four arms, which bear rotatable supports, Fig. 7, for bulbs and stems, and occupy each of four positions in succession. In the first position, a stem with filaments thereon is placed by an operator on a split tube 59 ; in the second, a shaped bulb is placed over it by the tranferring-arm 33, the filaments being protected as described below ; in the third, the two are heated preliminarily ; in the fourth, sealing is effected by two sets of burners 21, Fig. 4 ; and between the fourth and first positions the stem is pulled downwards to shape the seal and is then released so that the lamp may be removed. In the sealing-machine, the bulb rests in a cup-shaped support 54, Fig. 7, on standards 52 ; the support 54 can slide horizontally against a spring, and adjusts itself while a bulb is being placed in position, or it can be pushed back by hand. Damage to the filaments when a bulb is placed over a stem is prevented by a tubular sheath 69, Fig. 4. The sheath is in halves carried by pivoted arms on a plate 71, which is slidable horizontally in a head 72, and has camgrooves for opening and closing the sheath. When the plate 71 is slid towards the spider, the tubular sheath 69 is closed round the filaments on a stem ; a bulb is then lowered by the transfer arm 33 until it abuts against the sheath 69, and the two are then lowered together until the filaments are within the bulb, after which the sheath is opened and withdrawn. The sliding plate 71 and the sheath 69 are advanced and withdrawn by a pivoted rod 78 and a depending cam 80, and are raised and lowered on a rod 73 by a cam. In the sealing-position, the parts are rotated by a stud on a revolving plate 23, Fig. 4, on the table, a locking-rod 67 being withdrawn by a cam 68 at the centre of the spider. After sealing, the stem support 59 is pulled duwn by a fixed cam to strain and shape the seal, until tapering cam-surfaces 61 are pressed inwards on entering a recess, when the spring tube 59 releases the stem and enables the lamp to be removed. Specifications 12,737/02 and 12,730/06 are referred to.