Patent GB-774182-A (GB)
Title: Method of and apparatus for tinning leads extending from a surface of an article
IPC: H01J9/46
Filed: 1953-12-31
Abstract: 774,182. Cleaning and tinning vacuum tube leads. SYLVANIA .ELECTRIC PRODUCTS, Inc. Dec. 31, 1953 [Dec. 31, 1952], No. 36394/53. Class 82(2) [Also in Group XI] A machine for tinning the leads of a vacuum tube &c. comprises a turret machine having a manually loaded feed turret, a transfer mechanism and a main turret including a cleaning bath, a tinning bath and a washing bath, into the last named of which the tubes are discharged to be removed by a conveyer at the unloading station. Feed turret. The turret 10 carries a series of manually loaded tube receivers 12, and under-lying each of them is a pusher bar 46 (Fig. 3) with an upstanding blade part 48 to engage the tubes 15 in the receivers 12. The appropriate pusher bar ejects the tube into and through a tube support 18 and finally into the tube holder 16 on the main turret. Turret indexing. The main and feed turrets are synchronized and the main drive shaft 50 (Fig. 2) drives the main turret via a conventional Geneva mechanism having a drive roller 76 and locking plate 78 working on the Geneva wheel 68 (see also Fig. 1). This motion is applied to the main turret by a pinion 56 meshing with a circular rack 58. The feed turret is driven from the shaft 50 through gears 82, 84, the latter carrying the Geneva drive arm 88 engaging the Geneva wheel 90. A locking cam 94 is provided instead of the normal release plate and actuates a latch arm through the roller follower 100. Tube transfer. The pusher bar 46 (Fig. 3) at the transfer station is engaged via a depending roller 124 (see also Fig. 2) by a block 130 carried on a slide 118 operated by a connecting rod coupled to a bell crank lever 106 actuated by a cam 114 on the feed turret drive shaft. This effects the transfer of the relevant tube through the tube support 18 whilst the other pusher bars are locked by the rollers 124 riding in a circular track 126. The tube support consists of fixed and pivoted jaws, together defining a cylindrical space with a vertical slot to clear the pusher blade 48, and the movable jaw is pivoted out of the way by a cam 146 on the shaft 80 acting through a connecting rod 154 to allow the wires of the tube to clear the support when the turrets index. A spring-loaded finger in the cylindrical space exerts sufficient resistance to the entry of the tube to ensure that the blade 48 bears on the flat base of the vacuum tube (used as a reference surface) and does not bind on the leads. Main turret. The tubes are received on the main turret by holders 16 comprising two spring-loaded jaws, the lower jaw having a latch member preventing accidental opening. The holders are pivoted to a support member 158 slidably secured to the turret body 60 by rods 160, 160<SP>1</SP> and are held horizontally by two concentric rails. As the turret indexes the holders enter and ride between two "run-down" rails 178 which are arranged to move the holder and valve into a depending position at the cleaning station 22. The cleaning station comprises a trough-shaped vat 188 (Fig.. 2) with a compartment 190 for heating fluid. The support members 158 and holders 16 are received on to a head 194 (Fig. 1) which is lowered by a barrel cam 196 to a bottom position fixed by the length of rods 160, 160<SP>1</SP> The leads then move through the bath and are lifted by a similar head out of the bath and similarly taken through the solder bath 24. The leads are then immersed in a wash bath and carried through that as the turret continues to index. At the loading station 28 the valves are released into the wash bath and on to a conveyer 248 by a tube release 266 engaging the release pin of the latch member of holder 16. The tube release is operated by coupled cams 254, 256 acting through a bell crank lever 260. A lfting head similar to those used before lifts the empty holder on to rails 172, 174 by a " run up" section of track which moves the holders into a horizontal position for reloading.