Patent GB-524414-A (GB)
Title: Improvements in and relating to lamp making apparatus
IPC: H01K3/20
Filed: 1939-01-30
Abstract: 524,414. Electric incandescent lamp manufacture. BRITISH THOMSON-HOUSTON. CO., Ltd. Jan. 30, 1939, No. 3148. Convention date, Jan. 29, 1938. [Class 39 (ii)] In a machine for accurately locating a lamp filament with respect to the base, wherein a movable carrier with a lamp-supporting head thereon is moved before optical apparatus for indicating when the light-source is accurately located with respect to a reference surface, means are provided for causing the optical apparatus and the head to be accurately aligned in predetermined relationship when the carrier brings the head before the optical apparatus. The head 12, Figs. 1 and 2, is one of a series mounted on a turret 13 which indexes it through a number of stations at which capping operations are performed as described in Specification 247,923, [Class 39 (ii)]. The bulb 10 and cap 11, with a layer of cement between them are placed in the head 12 at the work-receiving station after lifting a spring-pressed finger 17 which is adapted to press on the cap, the bottom of the bulb being received in a suction-cup 21 connected to a source of vacuum. The end of the cap which engages the bulb is provided with a flange 22 which is located within a seating in an arm 23 on the head. The cup 21 is mounted on a slide 45 located in guideways in the upper face of a block 46 which, on its lower face, has guideways for a slide 47 provided with a boss 48 on a screwthreaded spindle 49, the guideways being disposed at right angles to each other so that the slides can be adjusted in two directions in a horizontal plane by the operation of two adjusting-screws provided with knurled heads 42, 43 respectively. Vertical adjustment is provided by a knurled wheel 44 on the spindle 49. After the insertion of the bulb and cap into the receiving head, the latter is indexed to the next station where it is brought before the optical apparatus 14, and the filament leads 18, 19 are gripped by jaws 29, 30 respectively which connect them to a source of current. The light from the incandescent filament is projected through two optical systems arranged in a housing 31 in the manner described in Specification 272,934, [Class 39 (ii)], and two enlarged images of the filament are focused on a frosted screen 28 provided with a horizontal hair line 41 intersected by two vertical lines 40. The position of the cup 21 is then adjusted by the operator until the images are centrally located about the intersections of the hair lines. The accuracy of adjustment is increased by positively locating the head laterally or circumferentially of the turret, and vertically with respect to the optical apparatus. The former is ensured by a radially movable plunger 56, Fig. 2, which is guided within a vertical bracket 57 and is adapted to engage within an aperture 58 in the frame 26 of the head 12. The plunger 56 is of such width that it engages the sides of the aperture 58, and is tapered at its end, so that it can turn the head 12 slightly horizontally when it is misaligned. Vertical clearance is provided for the plunger 56 in the aperture so that it does not affect the vertical position of the head. The plunger 56 is operated by a lever 59 pivoted at 60 on bracket 57. The heads 12 are aligned vertically by means of a roller 62 which is mounted on the end of the bracket 57 and engages the top horizontal surface of the arm 23 on the head, thereby either lifting the optical apparatus slightly or pressing the head 12 down to a given height, the slight adjustment necessary being acquired from the resiliency of the parts.