| 摘要 |
PURPOSE:To make possible continuous working of couplings by cutting the tape- form flat plate which has been subjected to piercing and tapping to convex shape continuously at every specified spacing and bending the cut plates thereby fitting the convex part into the recess of the other end to make it pipe-form. CONSTITUTION:A tape-form flat plate is unrolled and is chamfered by a roll 2 having a tapered surface 2a. Next, it is pierced with lower holes 3 by a punch and die, is worked with counter sinks 4 and is formed with tapping holes 4a. Also, it is engraved with the producer's name 5 and is embossed with stopper protrusions 9. Next, it is subjected to cutting including a convex part 6 which is wider at the end than the root, whereby the blank 8 of square plate form having the convex part 6 at one end face and a recess 7 at the other end face is formed. Thence, with a cylinder 9 as a core material, it is bent by a push rod 10 to let the convex part 6 fit into the recess 7. The chuck-form push rod 10 is then vibrated to swage the blank 8. Thereby, the blank 8 is formed to pipe form and the thread-less coupling A is obtained. |
