Patent GB-774361-A (GB)
Title: Device for handling the grids of electric discharge tubes
Inventor: GARTNER STANLEY JACOB
IPC: H01J19/46
Filed: 1955-10-27
Abstract: 774,361. Packaging machines. SYLANIA ELECTRIC PRODUCTS, Inc. Oct. 27, 1955, No. 30827/55. Class 94(1). [Also in Group XXX] Grids of electric discharge tubes are carried individually in buckets 14 on an intermittently driven conveyer chain 12 (see Group XXX) to a packing station at which trays 18, supplied from a magazine 20, (see Group XXX) are intermittently moved in two directions at right angles to each other to bring successive packets in the trays into position to receive a grid from a transfer device. The transfer device comprises a suction nozzle 16 carried on a tubular arm 124 rotatably supported about its longitudinal axis on an elevator frame 108 which is mounted by means of guide rods 102 in guide blocks 106. Operation of the arm and nozzle is initiated by closure of a switch 70 upon completion of a forward indexing movement of the conveyer chain (see Group XXX). This switch operates a reversing valve for a cylinder 72 whose piston rod moves a rack 78 and so rotates a pinion 80 on a shaft 82 carrying cams 92, 94, Fig. 6. The latter cam, through a bell crank 96, acts on one of the rods 102 to raise the elevator frame 108 so that the nozzle 16 is raised from register with a pocket in the tray. During raising of the elevator frame a roller 114 carried by an arm 116 pivoted to the frame rides along a vertical part of arm 112 of a bell crank 98 engaging the other cam 92. The latter now rotates the bell crank 98 causing arm 116 to swing whereby an upward extension of arm 116 tilts the nozzle 16 through a link 118, bringing the nozzle into register with a bucket 14. During these movements an abutment 126 on the elevator frame releases a switch 128 controlling solenoid 130 of a valve 135, whereby suction is applied to the nozzle. As the conveyer chain inducing mechanism (see Group XXX) is prepared for its next inducing movement switch 70 is opened, causing the movements of the nozzle to be reversed to bring the attached grid over the next pocket in the tray, the tray having meanwhile been induced under control of two switches 140, 142, Fig. 1, actuated by separate cams on the rack 78 at the two limits of its movement. As the elevator frame is lowered during the reverse movement of the nozzle, switch 128 is reclosed by the abutment 126, cutting off the suction from the nozzle, whereby the grid is deposited in the pocket. The tray inducing mechanism comprises a pair of endless chains 186 provided with propelling fingers 188 which engage the trays in turn as they are lowered onto a supporting surface by a vertically reciprocating table 154 cooperating with release catches 156 of the magazine 20 (see Group XXX). The chains 186 are carried on sprockets 190 on shafts 192 mounted, together with the magazine 20 and a further magazine 22, to which filled trays are delivered after inducing by a rising table 174, on a laterally sliding carriage 150. By suitably combining intermittent movements of the carriage and chains the tray is given a series of lateral movements corresponding to the number of pockets in a row across the tray, followed by a longitudinal movement corresponding to the longitudinal distance between the rows of pockets in the tray. The longitudinal movements are effected by expansion of a compression spring 200 acting through a rack 204 on a pinion (not shown) which is freely mounted on the sprocket shaft 192 but.coupled to a pawl carrier 220, Fig. 13, whose pawl 218 rotates a ratchet wheel 216 secured to shaft 192 until a pawl 226 engages a detent of detent wheel 224, also secured to shaft 192. Detent wheel 224 has a series of short detents corresponding to the number of transverse rows of pockets in a tray, and a long detent corresponding to the distance between the last row of pockets in a tray and the first row of pockets in a following tray. After an inducing movement the rack 204 is depressed to re-compress the spring 200 and return the pawl carrier 220 by a pneumatic cylinder 206 whose piston rod 208 has a lost-motion connection 210 with an upward extension of the rack, so that the piston rod 208 can then be returned to allow a further inducing movement to take place. Towards the end of its return movement the pawl carrier 220 engages the pawl 226 to lift it from the detent with which it is engaged, so that on the next inducing movement the pawl 226 will engage the next detent. A check pawl 222 is also provided to cooperate with the ratchet wheel 216. A switch 328 is actuated by a pin 326 on one of the sprockets 190 at the end of each movement, and another switch 230 is actuated at the completion of the return movement of piston rod 208. These switches are incorporated in a control circuit (not shown). Lateral movements of the carriage 150 and hence of the tray are effected by successive actuations of a reversible pneumatic cylinder 232, Fig. 3, movements continuing in one direction until the last pocket in a row is filled, whereupon a longitudinal movement of the tray takes place, followed by lateral movements of the carriage and tray in the reverse direction. Control of cylinder 232 is effected by a rod 262 secured to and extending laterally from the carriage and provided with recesses 264 equal in number and spacing to those of the tray pockets and cooperating with a switch 260 of the control circuit, and end stops 298, 304 cooperating respectively with switches 300 and 302 of the control circuit. In order that one, two or any desired number of grids may be deposited in each pocket of the tray the control circuit includes two switches 228 and 294, Fig. 7, switch 294 when actuated being adapted to initiate operation of the inducing mechanism. Switch 288 is actuated in timed relationship with the passing of each successive bucket 14 by pins 284 on a gear wheel 268 driven from the chain 12 through a sprocket 42 to which it is coupled. Wheel 268 is geared to a smaller gear wheel 270 which drives through a friction clutch, Fig. 8 (not shown), a shaft 272 on which are mounted a disc 276 carrying a pin 286 for actuating the switch 294, and an interchangeable disc 278 having a number of slots 282 according to the number of grids to be deposited in each pocket. A spring-loaded detent pawl 280 is adapted to engage these notches in turn, and to be withdrawn by a solenoid 290 which is under control of the switch 288. The inducing mechanism is thus not actuated until all the notches 282 have been engaged and released by the detent pawl 280. The control circuit includes an electronic relay which is controlled by a subcircuit completed by a grid attached to the nozzle, which is formed in two insulated parts, so that in the absence of a grid the actuation of switch 288 does not energise solenoid 290, and therefore no inducing movement can take place.