Patent GB-1075698-A (GB)
Title: Improvements in means for arresting lower moving punches in powder-compacting rigs
Inventor: REID JOHN DAVID
IPC: B30B11/02
Filed: 1965-09-09
Abstract: 1,075,698. Powder compacting presses. MARTIN BROS. (TOOLMAKERS) Ltd. Jan. 10, 1966 [Sept. 9, 1965], No. 38503/65. Heading B5A. A powder compacting press is provided with a die 11 in a vertically reciprocable die bolster 10, top relatively movable punches 12, 13, a lower fixed punch 15 carried on a fixed plate 17 and a lower reciprocable punch 14 carried by a movable punch plate 18. With the top punch assembly raised and moved aside and bolster 10 and plate 18 raised to the 10A and 18A dotted positions, the die 11 is charged with powder M by a hopper slidable on the upper surface of bolster 10 whereafter punches 12 and 13 are returned and lowered to compact the powder whilst the bolster 10 and plate 18 descend to the Fig. 2 position where punch 14 and plate 18 are arrested by the abutment of a set of radially directed teeth 26 on the underside thereof with corresponding teeth 25 on a rotatable detent ring 24 which is loaded into the engagement position, corresponding to the abutment of radially extending pins (29) with stop posts (31) (Fig. 1, not shown), by a pair of springs (28) or air cylinders. Upon further descent of die bolster 10, with the top punch assembly raised, the detent ring 24 is rotated by the engagement of the rounded ends of bars 32, fixed to the bolster 10, with rollers 33 on spindles 34, radially extending from detent ring 24, whereby detent ring 24 is rotated to permit the engagement of teeth 26 between teeth 25 so that the plate 18 and punch 14 fall and the tops of punches 14 and 15 and of die 11 become level and the moulded article is then pushed aside by the returning hopper which refills the die 11 when the plate 10 and plate 18 have been returned to the 10A and 18A position. In a further embodiment (Figs. 3 and 4, not shown) a fixed lower punch (15) is surrounded by a plurality of concentric lower movable punch assemblies (44 ... 47) the inner and outer (44, 47) whereof are provided with spline teeth) (52. 55) and the others whereof (45, 46) are provided with axially projecting teeth (53, 54) which are blocked and released by similar concentric Sets of teeth on a detent ring (24). The ring 24 may alternatively be rotated by a bell crank connection to bolster 10 and may be supported by a ball or roller thrust bearing 27. more than one lower fixed punch may be provided and the fixed punch may comprise an outer concentric member provided with a continuous annular surface for engagement with the teeth of the detent ring or the punch could be supported by pillars extending upwardly from fixed plate 17. Alternatively all punches may be movable and the central fixed punch dispensed with. Each concentric set of teeth on the ring 24 may also be offset so that the punches are released sequentially and the flank surfaces may be inclined or vertical. The lowermost positions of the punches may also be adjustably determined by vertical set screws. Detent rings may also be superimposed to increase the travel of the punches after release or detent rings may be employed one inside another.