GB641685A - Improvements in or relating to method of and apparatus for forming nut blanks - Google Patents

Abstract

641,685. Forging nuts; dies. WATERBURY FARREL FOUNDRY & MACHINE CO. Jan. 21, 1948, No. 1826. Convention date, July 31, 1947. [Class 83 (iv)] A method of making a nut blank with a flat face surrounding the opening through the blank, includes the steps of cutting a blank from solid stock, cupping the face at one end and then applying pressure to the blank to form an annular recess in the cupped face adjacent the outer portion of the face. The machine for carrying out the invention comprises a number of dies in a block 10 co-operating with a movable gate 13 carrying a number of co-operating dies. At the first station a blank is sheared from the stock 15 and fed by the cutter 16 to a position in front of a die 19 at station 2. As the gate advances the blank is pushed into the die 19 by a pin 33 projecting through a punch 27 and as the punch advances the blank is pressed between the die 19 and a die 29 carried by the punch so as to form the shape shown in Fig. 7. The depression 37 on the upper face is formed by the end of the knock-out pin 23 which constitutes the bottom of the opening of the die 19. The blank is transferred to the third station by known transfer means and is there pressed between dies 41 and 47 and pins 43 and 49 to the shape shown in Fig. 8, having flat sides joined by rounded corners, a lower face with two annular portions of different taper and an upper face with an annular depression 57 surrounding a flat central portion 58. At the fourth station the blank is upset between a die 66, 67 and a punch 73 so as to form a polygonal cross-section with sharp corners, an upper depression made by a pin 69 and a lower deeper indentation made by the shaped upper end of the punch 73. At the last station the blank is seated in a die 84 and a hole is punched through it by a punch 82 from which the work is removed by a stripper 87.