Patent GB-961928-A (GB)
Title: Method and apparatus for treading lamp caps
IPC: H01J9/32
Filed: 1959-08-28
Abstract: 961,928. Threading electric lamp caps. ASCOT LAMPS & LIGHTING Ltd., and F. W. JEFFERIES. Aug. 26, 1960 [Aug. 28, 1959; Oct. 8, 1959], Nos. 29520/59 and 34083/59. Heading H1J. In a method of threading the leading-in wires of an electric lamp through holes in the cap, the extremities of the wires of each lamp are held in predetermined positions by locating means engaging the wires adjacent the extremities and guides passing through the holes in the appertaining cap are caused to pass over such extremities while these remain so held by the locating means whereafter the wires are caused to pass through the cap holes by imparting relative movement to the cap and bulb while the guides remain over the extremities of the wires. The method is applicable to bayonet type caps in which two leading-in wires are threaded simultaneously or to Edison screw caps in which a single leading-in wire is threaded. The method comprises the following steps, mechanism for which is described: (1) applying an indicating marking to a predetermined position on the lamp mount and orientating the bulb automatically in accordance with the marking; (2) loading the bulb into the threading machine in adjusted position; (3) straightening the leading-in wires and orientating the caps, to which adhesive paste is applied before or during delivery to the machine; (4) cutting the leading-in wires to the required length and cleaning the holes in the caps; and (5) threading. Apparatus of the indexing type is described for each process. The mounts are masked while on the carrier of a filament mounting machine of the rotary indexing type by means of a spray of sodium silicate applied through a marking slot, the markings being made at 90 degrees to the plane of the pinch, and are orientated during transit to the exhausting machine after the mounts have been sealed into the bulbs. The bulbs are carried by an indexing conveyer 16, Fig. 4, to the orientating station at which the position of the exhaust tube T is adjusted by a pair of arms 26, 26<SP>1</SP> to enable a pin on a vertically movable shaft to enter the tube and raise the bulb into contact with a roller driven by an electric motor 32. The motor is controlled by a photo-electric cell positioned below the lamp mount and continues to revolve thereby turning the bulb until light falling on the cell from a source S is interrupted by the masking on the mount. After exhausting and sealing the bulbs, they are transferred to an indexing turret having six positions. At B, Fig. 6, the bulbs are loaded on to the turret, the orientating being maintained, at C already pasted caps are delivered by a shoot C<SP>1</SP>, at D the leading-in wires are straightened and the caps orientated, at E the wires are cut and the holes in the cap cleaned, at F the threading is effected and at G the capped bulbs are offloaded to a machine for soldering the wires to the caps in the usual manner. The bulbs are supported in recesses in a plate 34, Fig. 7, below each of which is a pair of bulb centralizing jaws 38, and the caps are held in jaws below recesses in a second plate 35, the two plates 34, 35 being driven in unison by a shaft 40 through the centre of which passes a non-rotating spindle 42 carrying arms 43, the outer ends of which have spring loaded plungers 44 coinciding with the positions D, E and F. The spindle 42 is alternately raised and lowered by cam means in timed relation to the indexing of the turret so as to press the bulbs on to their seatings on the plate 34 during each period of dwell. At station D two sets of wiping arms pivoted on horizontal axes engage the leading-in wires and straighten them so that they project vertically downwards from the bulb. At the same time, a spindle having a pair of opposite lobes is moved vertically so that the lobes engage the bayonet pins of the cap and is rotated to bring the holes in the cap to the desired portion opposite the wires. At station E, the leading-in wires are gripped by a pair of arms 91, Fig. 20, carried by a pair of inner shafts 97, and cut to length by a pair of cutters on arms 92 carried by a pair of outer shaft 98. Each pair of shafts 97, 98 are geared together and oscillated by a separate linkage. A pair of drill heads 102 with meshing pinions 103 are mounted in a bearing block 104 vertically displaceable on a guide block 105 so that they can be simultaneously rotated and displaced upwards for clearing the holes in the caps. At station F, the leading-in wires are gripped by two interleaved pairs of notched plates carried on the ends of arms 115, Fig. 24, mounted on parallel shafts 112 connected by meshing gears 113. The lower plates are cut away to form leadin passages into the base of which the leading- in wires project to a small extent. Parallel tubes 124 carried by heads 121 connected by meshing pinions 122 driven from a spindle 123 extend through holes in arm 126 and are movable vertically upward by displacement of a rod 119 carrying a block 120 in which the heads 121 are mounted. During the first part of their ascent the tubes 124 are rotated. The tubes pass through the holes in the cap and engage the tips of the leading-in wires. The supporting arms are then swung apart and the arm 126 begins to rise with the tubes 124 thereby bring- ing the cap into contact with the bulb, a pair of jaws engaging and retaining it in this position. The tubes are then withdrawn and the bulb with the cap in position indexed to the unloading station. The threading machine is operated by a main shaft connected by bevel gearing with a geneva mechanism for indexing the turret, the main shaft and two shafts geared thereto carrying sets of arms for operating the various mechanisms. Specification 961,929 is referred to.