GB1198537A - Improvements in or relating to Hydraulic Presses. - Google Patents

Abstract

1,198,537. Hydraulic presses, cutting out presses. A CHIESA. 28 March, 1968, No. 14863/68. Headings B4B and B5F. An hydraulic press having a pair of spring retracted relatively movable press parts, includes a pair of stroke limiting abutment members, one adjustably mounted on each press part, and a control element operative to initiate the return stroke of the press either simultaneously with or just before the abutment members meet at the end of the approach stroke of the press parts. In the embodiment shown in the figure, in which material L is cut by tool M, reciprocable platen C is carried by bracket D mounted upon the end of a column 10 slidable within pedestal A upon which table B is mounted. The column is adjustably connected by nuts 18 to a spring biased rod 16, the lower end of which is attached to piston 28 slidable within a cylinder 30 fixed to pedestal A. The lower end of the piston is provided with an abutment rod 40 adapted to contact a surface 50 of a stepped slider 44 reciprocably mounted upon pedestal A, and microswitches 52, 54 mounted beside each surface 50. In operation, pressure fluid is introduced by pump G into the cylinder to initiate the working stroke, the stroke continuing until rod 40 abuts a surface 50. Simultaneously to, or slightly before the abutment the associated microswitch is actuated to connect he cylinder to reservoir thus initiating the return stroke under the action of spring 32. In a second embodiment (see Fig. 2, not shown) the bracket D is located part way along column 10 and the upper end of the column slidably projects through a ring carried by the upper end of sleeve 22, which sleeve has been extended upwardly. In this embodiment, the abutment members comprise a screw threaded ring adjustably mounted upon the upper end of the column and the upper surface of the ring, a stroke reversing microswitch being located adjacent the ring.