| 摘要 |
<p>1389953 Making pipe bends; stamping COMBUSTION ENG Inc 27 Dec 1972 [29 Dec 1971] 59677/72 Headings B3A and B3Q Apparatus 31 for cold forming a half torus 10, Fig. 1, from an annular flat plate P comprises a first base or lower platen 34, a second base or upper platen 60 actuating means for moving one of the bases towards the other, a female die member 32 extending from the first base, the die member 32 having a cylindrical surface 56 for locating and retaining the plate P 1 two cylindrical surfaces 42, 48 defining an annular channel 40, and a cylindrical outer surface 36; and a male die member 58 extending from the second base and having a first plunger 64 for cold forming the plate in the channel 40 and a second plunger 62 for flanging the plate, the plunger 62 being positioned to permit its passage along the outside of the surface 36. The plate P is initially supported at its centre on the surface 52 and at its periphery on a rounded lip portion 46 of the die member 32. As the platen 60 is lowered the plunger 62 forms the plate into a shallow cup (P<SP>1</SP>), Fig. 4 (not shown), having a downwardly flanged edge (94). This operation prevents wrinkling of the material as the plunger 64 subsequently forms the cup (P<SP>1</SP>) into a halftorus (P<SP>11</SP>), Fig. 5 (not shown). The die member 58 is withdrawn and an actuating shaft 84 of ejection means 82 drives spider arms 88 upwardly to force the half-torus out of the die member 32. Two half-tori 10 are welded together by being turned under an automatic welding head and subsequently cut into sectors, such as sectors 20, 22, 24, 26 to form pipe bends.</p> |
