| 摘要 |
1,072,973. Screwing die heads. GEORG FISCHER A.G. Jan. 28, 1966 [Jan. 29, 1965], No. 4039/66. Heading B3N. A stock and die for cutting a conical screw thread on the end of a pipe 1, Fig. 1, comprises thread-cutting dies 21 adjusted for cutting diameter by a nut 17, a sleeve 2 having screw threads 11, 12 of different pitch, and a rod 4 in the sleeve, which actuates a wedge 8 to clamp the pipe. A nut 13 is secured to a housing 15 which latter can be rotated by a ratchet 26, or in a modification, the ratchet is replaced by an auxiliary gear system, Figs. 3, 4 (not shown). In operation, wedge 8 is inserted into the pipe 1, and clamped by turning nut 6. The screw thread 11, and that on nut 13, have the thread pitch desired on the pipe, and the pitch of screwthread 12 and nut 17 is smaller. Housing 15 is rotated and moves along thread 11, whilst nut 17 moves axially at a slower rate, and therefore moves the dies slowly in an outward radial direction, to thus form a conical thread on the pipe. The auxiliary gear system, Figs. 3 and 4 (not shown); comprises a housing (31) and a cover (32), a toothed annulus (36) located between members (31), (32) and keyed to housing (15) by a key (33a), a shaft (34) having a pinion (35) which drives annulus (36) by a further pinion (38), and a guide (39) freely rotatable on shaft (34) and fitted on to sleeve. (2). For thread-cutting, a lever is mounted on the square head (37) of shaft (34), and housing 15 is rotated through gearing (35), (38), (36). |
