GB1313312A - Hydraulic presses - Google Patents

Abstract

1313312 Moulding powder PARKERHANNIFIN CORP 3 Aug 1970 [29 Aug 1969] 37332/70 Heading B5A An hydraulic powder compacting press includes a die platen 11, upper punches 39, 40, lower punches 20-22 and a core rod 6. A fixed head 2 supports an hydraulic motor for reciprocating the core rod and four pairs of motors for reciprocating, respectively, the die platen and the lower punches. The lowermost and uppermost positions of punch platens 14-16 with which the lower punches are associated are determined by stop collar's 26, 27 on fixed columns 25; collars 28, 29 determine the extreme position of platen 11 and collars 30, 31 the extreme positious of the core rod. The upper punches are separately driven by hydraulic motors and have depending stop rods which engage the platen 11. The distances apart of the platens 14-16, as they are driven upwardly, are determined by floating spacer columns 50, with adjustable stop collars 51, which are slidably guided in the head 2 and platen 11 and extend through the platens 14- 16. Fixed stop collars 52 on the columns 50 engage the punch platen 35 during this upward movement and the upper ends of the columns engage the punch platen 37. Thus the punch platens are accurately located relative each other to form the article. A powder feed hopper supplies an hydraulically driven reciprocable powder feed box on the die platen 11, and after supplying powder to the die cavity, Fig. 7, the upper punches are moved down to seal the cavity and the lower platens are driven upwardly, in sequence, to the position of Fig. 8 to produce the article A to precise size. Downward pressure on the upper platens 35, 37 is then decreased and all platens are driven upwardly by the lower hydraulic motors. The punch 22 is first moved to a position flush with the die platen, followed by punch 21, and the article is finally ejected as the punch 20 is moved to a flush position; during such movement the article is stripped from the core rod. Alternatively the core rod may be removed from the article before article ejection. The upper punch platens are raised from the article before its complete ejection, Fig. 9. When an article is to have a recess in its upper end, the platen 11, after being powder filled is raised slightly to engage stop collar 29, causing the powder level to lie below its top surface. During the pressing the platen is lowered to engage the stop collars 28. An hydraulic circuit, with pumps, pressure switches, solenoid valves, timers &c. is described for controlling a cycle of operations.