| 摘要 |
1,257,672. Bending blanks. VYZKUMNY USTAV TVARECICH STROJU A TECHNOLOGIE TVARENI. 7 Feb., 1969 [10 Feb., 1968], No. 6675/69. Heading B3E. Profiled blanks are bent to a configuration consisting of successive portions of curves of different radii of curvature by placing a blank on a bending die, shaping the portions of large radius by means of rolls moving over the surface of the blank on the die and then shaping the portions of small radius by maintaining the rolls stationary and pivoting the die so that the rolls wrap the blank around a part of the die having the small radius. An apparatus for carrying out the method comprises a frame 1 in which is pivoted at 2 an arm 3 carrying rolls 19 in a housing 12 mounted at the end of a cylinder and piston assembly 7, 8, 9 which provides an adjustable force on the blank. A die 30 is mounted on bolsters 29 pivoted about a pin 28, and means is provided for moving the arm 3 from the vertical to an inclined position (shown by chain dotted lines) and for moving the die 30 about pivot pin 28. The bolsters are held in position by blocks (41) Fig. 3 (not shown) during the bending of the blank to a large radius after which they are withdrawn into passages 39 which allows the pivoting of the die about pin 28. The blanks are held on the die by a clamp 38 and one half of a blank is shaped at a time. |
