Patent GB-921501-A (GB)
Title: Improvements in or relating to reducing devices, preferably for reducing cylindricalpieces of work which are cut to length from wire
IPC: B21C1/18
Filed: 1959-07-30
Abstract: 921,501. Making pin-screw blanks; drawing; extruding. J., PLAGEMANN. [trading as PEEWEE MASCHINENUND APPARATEBAU WERNER PLAGEMANN]. July 30, 1959 [July 31, 1958], No. 26253/59. Classes 83 (2) and 83 (4). In a reducing device for reducing work cut from wire which is to be thread-rolled over two reduced shank portions e.g. for pin screws, wherein there are two coaxial reducing dies 14, Fig. 4, which have stops and ejectors and which are relatively movable by an hydraulic drive with a feeding means between the dies, each of the dies 14 is mounted on a pressure-controlled spindle sleeve 2, the first or right-hand spindle sleeve 2, advancing to the left to reduce one end of the blank until a stop nut 26 engages a stop 30 at the same time actuating a limit switch 34 which initiates a loss of pressure on the first spindle sleeve while the second or left-hand spindle sleeve 2 receives pressure to advance it to the right when it strikes the first spindle sleeve 2 and moves it back, the work 43 being held axially by the ejector pin 23 while the die 14 of the left-hand sleeve moves over the work to reduce the other end of the blank until a stop similar to the stop 26 operates a second limit switch similar to the switch 34 which causes a reversal of pressure and the return of the sleeves to their initial position. Each die 14 is attached to an exchangeable head 13 of the sleeve 2, the head and sleeve being bored out to receive an ejector rod 17 at the inner end of which is an ejector pin. The ejector pin 23 of the right-hand sleeve is fixed to the rod 7 while the ejector pin 23a of the left-hand sleeve is resiliently mounted on its rod so that during the advance of the right-hand sleeve the blank enters the stationary left-hand die against the pressure of the ejector pin springs and is thus centred accurately. During movement of both sleeves to the right to reduce the left-hand end of the blank, the latter is held stationary by the ejector pin 23 while the die moves over it, the length of the collar on the finished blank being determined by the setting of the adjustable ejector pin 23. In the full cycle of operation the right-hand sleeve moves outwards after completion of a reduction operation on a previous blank until the stop nut 29 engages the abutment 31 and actuates a limit switch 37 which locks the switching circuit against a rhythmic switching impulse emitted by a constantlyoperated control drum the action of which is synchronized with the blank-cutting shear and with the feeding device (not described). As soon as the left-hand sleeve has returned fully to the left a similar limit switch 37 is operated by another outer stop 29 which switch 37 initiates a new impulse from the control drum to energize magnets 63, 50 and bias auxiliary and main hydraulic control pistons 58, 44 to the left and permit the movement of the right-hand sleeve to the left. On reaching the left-limit position of the right-hand sleeve the switch 34 operates to energize a magnet 64 and deenergize the magnet 63 so that the auxiliary piston 58 moves to the right de-pressuring the right-hand cylinder 6 and causing the advance of the left-hand sleeve by admission of fluid to its cylinder 6. On completion of the advance stroke of the left-hand sleeve the switch 34 operates to energize a magnet 51 while deenergizing the magnet 50 thus causing the control piston 44 to move to the right which admits fluid through the pipes 7 to return both sleeves to the starting position. The work is wholly supported prior to engagement with the dies by apertured metal plates 39, 40. Lubricating oil is supplied to the sleeves through pipes 9, 10.