GB130771A - An Improved Method of and Apparatus for Drawing Metal. - Google Patents

Abstract

130,771. Marks, E. C. R., (Rockwood Sprinkler Co.). Aug. 8, 1918. Capsules, caps, and like cupped articles.-Hol- .low metal articles such as containers or caps, are formed with cylindrical insides and with conical exteriors which thicken towards the upper open ends of the shells, flanges being formed in their upper ends if desired by upsetting the conically formed member in a conical die 71, Fig. 9, which is shaped to receive the formed cup a<6>. The blanks a to be formed are first shaped by a series of plungers as 12 - - 52, and corresponding dies 10, 50, of decreasing sizes, which form a cup as a<4>, Fig. 6, having a slightly thickened upper part. The cup a<4> is then treated in a drawing press, Fig. 7, being forced by a plunger 57 formed with a thickened lower end, and with a recess 58 which forms a shoulder on the cup a<5>, which is stripped from the plunger by a stripper 64 carried by a plate 62 acted on by springs 61 which move the plate 62 over guide bolts 60 until arrested by nuts 63. As the plunger 57 ascends, it draws out the metal and forms a true cylindrical surface inside the cup a<5>. The final shaping of the cup is effected in a die 71, Fig. 9, which is conical, and is formed with an annular recess 72 in its upper part. The metal is pressed into this recess by a die 77 which upsets the metal in a longitudinal direction. The plunger 73 is arranged in a recess in the press head, and is normally pressed downwards by a strong spring 81 acting on a plate 79 which abuts on a shoulder on the plunger 73. Vent holes 66, 84, 85, 86 are formed in the plungers and dies. A screw thread may be formed on the top flange of the finished article.