Patent GB-273970-A (GB)
Title: Improvements relating to the manufacture of thermionic valves and like discharge tubes
IPC: H01J19/46
Filed: 1927-01-10
Abstract: 273,970. Naamlooze Vennootschap Philips' Gloeilampenfabrieken. Aug. 12, 1926, [Convention date]. Electric fittings.-In a machine for mounting the electrodes on the supporting and leading-in wires of the feet of thermionic valves after dressing and shaping the wires, the feet 8 are mounted in carriers spaced around an intermittently rotatable table 1, and are operated upon at several positions A - - H around the table. Each carrier comprises a fixed jaw 6 and a spring-operated jaw 7, the jaw 6 having a finger 12 to engage the edge of the pinch of the foot. At position A, a pair of arms 28 pivoted at one end on a sliding carrier are provided at their free ends with combs which are closed upon the wires and then moved radially outwards to straighten them. At position B, the outer or cathode leading-in wires are bent outwardly, to provide space between them for the grid and the anode, by spreaders 60, 61, Fig. 7, formed on the ends of levers 56 pivoted on a sliding carrier 42. This is moved inwardly to insert the spreaders between the wires, and then the levers strike fixed stops 70, 71 which cause them to separate and shape the wires against fixed abutments 63. At position C, all wires are trimmed to length by cutters mounted on one end of pivoted levers 88, 89 actuated by a cam 97. At position D, the ends of the cathode leading-in wires are flattened between anvils 113, 114, the movable jaws of which is actuated by a cam on a shaft 118. At position E, the flattened ends of these wires are bent to form hooks to receive the filament. The flattened ends are first clamped against an abutment 135, Fig. 15, by the end 136 of a lever 137, the end 136 acting as a former over which the wires are bent by noses 156 on a bender 144. This is pivoted at 145 in a lever 142 which is pivoted at 143 on a carrier 126 and adapted to berocked by a cam 150. As the carrier 126 movesinwardly, the noses 156 engage behind the wires and a bevelled surface 134 forces the bender over against the action of a spring 147 to form the hooks. All the mechanisms described above are mounted on radially sliding carriers so that they can move out of the way of the glass feet during- their circular transit. At position F, the feet are brought into register with grids mounted in carriers spaced around an intermittently rotating table 165. The spring jaws of these carriers are opened by handles 164 for loading the grids, and automatically for releasing them after they have been welded to their wire supports. The helix of each grid 157, Fig. 19, is attached to a wire bent twice at right-angles, as shown, and the ends of this wire are registered with the support wires 160, 163 of the foot, and welded thereto by welding-pins 182, 183 resiliently mounted on a pair of cam-actuated levers. At position G, the anodes are formed from flat plates and welded to the support wires. The plates are secured in clamps spaced at intervals around an intermittently rotating table 198. Each clamp comprises two stops 206, 207, Fig. 22, provided with grooves to accommodate the ends of the anode plate 210, and a third stop 205 to press the plate against the other stops. The stop 205 is curved to the radius of the required finished anode, and when all the stops are advanced presses the centre of the plate on to a cylindrical former 211,. while the stops 206, 207 leave the plate, as shown in Fig. 23. The former 211 is longitudinally slidable so as to be brought into position around the grid 157, and is slotted to clear the wires. The plate 210 is finally completely bent around the former and its ends registered with the support wires by a pair of fingers 246, 247, Fig. 24, formed on the ends of cam-actuated levers. The anode is secured by welding-pins 253, 254 carried by a lever 261 and adapted to be brought together by a cam 277, a lever 272, and links 268, 271. At position H, the filaments are secured to the leading-in wires, and at the final position O the finished feet are unloaded.