Patent GB-600463-A (GB)
Title: Improved method and means for making nut blanks or the like
IPC: B21K1/70
Filed: 1944-07-11
Abstract: 600,463. Forging nuts. WATERBURY FARREL FOUNDRY & MACHINE CO. July 11, 1944, No. 13245. Convention date, July 12, 1943. [Class 83 (iv)] Dies; shearing adjuncts.-A method of producing a nut blank or the like from a solid piece comprises forming a recess in one end and externally coning the opposite end by endwise pressure applied at the same time or station, then deepening the recess while retaining the externally coned end, shaping the piece so that a portion thereof is polygonal in cross-section and piercing a hole through the piece coaxially with the recess. Within a die block 16 secured within the framework 10 of the machine are a plurality of sets of dies and associated parts adapted to co-operate with a set of punches mounted in holders 19 secured to a member 12 reciprocated by a pitman 15 from a crank-shaft 11. At station 1 (not shown), rod stock is fed through a die by known means, is sheared and  moved by a transfer mechanism, not. described, to a position in front of the die at station 2. Threaded into the die block 16 at station 2 is a sleeve 31, Fig. 4, within which is a die 32 having a bore, of the same diameter or slightly larger than the diameter of the work-piece 29, into which bore projects a punch 35 formed with a conical end. The die is normally urged to its outermost position by a spring 34. The punch-holder 19 at station 2 carries a punch 37 formed at its outer end with a recess 27  having a conical bottom wall. Within the punch 37 is a cup 40 and a slidable sleeve 42 urged outwardly by a spring 43 and within the sleeve a headed pin 39 urged outwardly by a spring 45 and abutting the inner end of a pin 26 which normally projects beyond the end of the punch. The rear end of the cup 40 bears against an adjustable fixed wedge 46 in the member 12 through the ball end of an arm 47. As the punch is moved forwards by the member 12, the pin 26 contacts the work 29 and moves it from the transfer mechanism into the opening of the die 32. During the further advance of the punch 37, springs 43, 45 and 34 are compressed until the end of the pin 39 bears against the end of the cup 40 and the recess 27 has moved over the work 29. Further movement of the member 12 compresses the work so that the conical portion 28 of the recess forms the conical portion 82 and the punch 35 forms the conical recess 44 as shown at B, Fig. 15. As the backward movement of the punch 37 begins, the arm 47 is actuated to cause the pin 26 to eject the work from the recess 27 into the die opening 32 from which it is later ejected into the transfer mechanism by the punch 35 under the action of a knock-out pin 52 operated by known means. The arm 47 is actuated by means of a roll 136 adapted to engage a cam surface mounted on a cap 14 above one edge of the slide 12 and moved into the path of the roll 136 by a lever 145 actuated from a cam 143. Alternatively, the cam surface may be rigidly secured to the cap 14. In a modified form of punch for operating on smaller blanks at the second station, the sleeve 42 is dispensed with and the pin 39 is urged forwardly by a single spring, Fig. 14 (not shown). At the third station is a die 53 movable rearwardly within a sleeve 54 against the action of a spring 57, Fig. 9, and having a bore of two different diameters joined by a throat 59. A punch 61 projects into the die and co-operates with a punch 65 carried by the member 12 to deepen the recess 44 and cause the sides to flow into the throat 59. After the withdrawal of the punch 65, punch 61 is actuated by knock-out mechanism to eject the blank, this operation also restoring the outer cylindrical form of the work which is now as shown at C, Fig. 15. At station 4 the work is compressed in a polygonal die 71, Fig. 10, by a punch 85 having a similarly shaped end to form the blank shown at D, Fig. 15. At station 5, the blank is inserted in a die 99 with the wall of the recess 84 projecting into a block 100 and around a sleeve 106 which surrounds a piecing punch 103. Member 12 carries a punch 80 with an annular end which co-operates with the reduced end of the punch 103 to remove a slug 111 which is ejected through a side opening 95 of the punch 80. After the withdrawal of the punch 80 the die is held in the rearward position by a pin 112 while the sleeve 106 is advanced to strip the work from the die and from the punch 103 and then move it into the transfer 'mechanism which moves it to a discharge station. The pin 112 is urged downwardly by a spring within a barrel 120 and is raised to release the die by means of levers operated from a cam 129 on the crank-shaft 11.