| 摘要 |
1399852 Compressing helical gears ING C OLIVETTI & C SpA 19 April 1973 [4 May 1972] 18944/73 Heading B5A A helical gear 10 (Fig. 1) is moulded from metal powder by compression within die parts 16, 17 (Fig. 2), part 16 having a toothed internal profile corresponding to that of the gear to be moulded. An upper punch 21 (Fig. 2) and guide plate 24 are lowered on to locating pins 18 and bearing feet 26, and the punch 21 enters and rotates within the die part 16 for compression about a core 20. The outer surface of the punch 21 is toothed and engages the teeth of the die part 16 and also helical teeth within a guideplate 31 that are aligned with the die teeth to guide the punch rotation during compression. A lower punch 10 rises for compression. Afterwards the core 20 is lowered, followed by the lower part 17 of the die, and the lower punch 19, to leave the die part 16 engaged with the upper punch 21. The upper punch 21 then rotates to push the moulded gear from the die part 16, for subsequent sintering. The gear comprises helical teeth 11 (Fig. 1) and a hollow hub 12 having a key 13 and hub apertures (not shown). |
