Patent GB-819408-A (GB)
Title: Improvements in or relating to indexing equipment
Inventor: EADON-CLARKE CHRISTOPHER ERSKI
IPC: H01H43/10
Filed: 1957-08-27
Abstract: 819,408. Induction heating equipment. STANDARD TELEPHONES & CABLES Ltd. Aug. 27, 1957, No. 26979/57. Class 39(3) [Also in Group XXIV] Indexing equipment which may be used in conjunction with induction heating equipment includes means for obtaining continuous rotation of a work supporting table, and control means for selecting any one of a plurality of predetermined indexing cycles whereby the number of indexing positions at which the indexing table stops during a complete revolution is variable. As shown, an indexing table 13 is mounted on a shaft 5 to which is secured a locating wheel 20 having sixteen equally spaced countersunk holes 21 of a diameter equal to that of two diametrically opposed locating rods 18 provided on a fixing plate 6. The under surface of the wheel bears on a clutch plate 22 supported on a gear wheel 23 which is rotated through reduction gearing by a reversible motor (not shown). A cam fixing block 29 is located on the shaft 5 by a key 39 engaging in a keyway 40 and has cams 30, 31, 32 attached to it, notches on the cams causing operation of microswitches of which only one 34 is shown. The cams 30, 31, 32 have sixteen, eight and four notches respectively and by setting a switch 8 to select one of the three microswitches, provide the appropriate number of indexing positions at which the table stops during a revolution. An extension 44 of the shaft 5 is adjustable to alter the upward lift of the shaft which is movable upwardly by a push rod 50 of a compressed air cylinder 47. A three-position clutch lever 9 pivoted at 52 has pins 53, 54 which slide under the boss of the table when the lever is moved from its central "clutch engaged" position, and cause the locating wheel 20 to be raised clear of the clutch plate 22. A switch 42 operated by a block 41 on the lower end of the shaft 5 switches the heating equipment on and off as the table is raised and lowered. Operation. With the control switch 8 set to select say, microswitch 34, and the clutch engaged, the gear wheel 23 is continuously driven at constant speed and the cams 30-32 rotate. When the switch is operated by a notch of the cam 31, a solenoid opreated air control valve causes the shaft 5 and table to be raised by the air cylinder push rod 50. Simultaneously, the clutch is disengaged by the raising of the wheel 20 and the gear wheel 23 continues to revolve on the shaft 5. The locating rods 18 enter two of the holes 21 to lock the table against rotation whilst lifted and the table is held in its raised position for a time determined by a process timer 10, after which the table assembly falls under gravity and the clutch is re-engaged. The shaft is then rotated until the next cam notch operates the microswitch and the process is repeated. By moving the clutch lever to the left, the pin 53 causes the table to be lifted slightly, the drive ceases and the table is free to be turned. If the lever is moved to the right, the pin 54 imparts a greater lifts such that not only is the drive broken but the table is locked by the rods 18 entering two holes 21. The control switch may be set to hold the air cylinder 47 operated and to lock the table in the upward position, or to cut off operation of the cylinder.