Patent GB-388878-A (GB)
Title: Improvements in and relating to machines for making electric lamp bulbs and the like
IPC: H01J5/24
Filed: 1931-11-28
Abstract: 388,878. Making electric incandescent lamps. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.- (Assignees of Patent-Treuhand-Ges. fur Elektrische Gl³hlampen; 11, Ehrenberg-strasse, Berlin.) Nov. 28, 1931, No. 33032. Convention date, Nov. 28, 1930. [Class 39 (ii).] In a machine adapted to form a shoulder in the neck of an electric incandescent lamp bulb by pressing the neck inwardly when in a semi-molten or plastic condition, means which operate simultaneously with the shoulderforming operation are provided to form, in a region below the shoulder, an indentation or a number of recesses which are adapted to receive a cementing medium for the securement of a cap or socket when fitted with one end in abutment with the shoulder. In the position of the sealing-machine in which the pedestal 7, Fig. 1, is fused into the constricted neck 21 of the bulb 1 and the surplus part 2 of the neck still forms one piece with the bulb, two moulding-jaws are provided on opposite sides of the neck, upon arms 48, 49 mounted on pivots 50, 51 carried by two slides 19 that are movable towards one another. The outer ends of the arms carry rollers 48<1>, 49<1> which are engaged in slots 80, 81 in guides 16 slidably mounted on the slides 19. The jaws 48<2>, 49<2> on the arms 48, 49 are arcuate and arranged so that when closed they form a complete circle surrounding the neck of the bulb, as shown in Fig. 2. The upper faces of the jaws are provided with moulding-plates 45, 46 carrying top plates 42, 43 arranged so that moulding- wedges 45<2>, 46<2> on the moulding-plates project inwardly towards the bulb neck and produce an encircling shoulder 3 when the jaws are closed upon the semi-plastic neck. To the underside of the jaws 48<2>, 49<2> are fastened four jaws 83 which project inwardly and, in the closed position, form a square opening without touching one another, thereby forming within the neck of the bulb four pocket-shaped recesses 84, Fig. 4, disposed between the shoulder 3 and the edge 5 of the foot 6. The arms 48, 49 together with the slides 16, 19 are mounted on sliding members which move backwards and forwards in the direction of the arrows A, B, Fig. 2, and before a bulb is carried into the operative position of the moulding device the latter is moved in the direction B, the slides 16, 19 being then in their outer position and the arms opened. As soon as a bulb enters the operative position and the pedestal 7 is fused into the neck 2<1> the moulding-device is moved in the direction A and the slides 16, 19 are moved inwardly. The slides 19 are arrested by abutment members, whereupon the slides 16 continue to move and cause the jaws to close. The shape and regulation of the moulding-arms may be modified, for example, by providing only one moulding-arm with semicircular jaws which entirely surround the bulb neck. The number and shape of the additional jaws for forming the pocket shaped recesses may also be varied. In order to obtain a sharp-edged and accurate formation of the shoulder and recesses air may be blown into the bulb in known manner through the exhaust tube 85, Fig. 1, and the hole 86 in the pinch. Specification 355,220 is referred to.