GB1151738A - Improvements in Oleopneumatic Pressure Transformers - Google Patents

Abstract

1,151,738. Hydraulic intensifiers. CROUZET. Sept. 26, 1966 [Oct. 11, 1965; July 22, 1966], No.42804/66. Heading F1P. A compressed air actuated hydraulic intensifier comprises a piston 5, Fig. 2, having a rod 6 of relatively large cross-section which extends upwardly through and in sealing engagement with a central aperture in an upper end plate 3 of the vertical cylinder 1 to provide an oil-filled annular chamber 8 from which pressurized oil is discharged through a port 3b in plate 3 when piston 5 and rod 6 are urged upwardly by compressed air admitted through a port 2b into the cylinder chamber 7 beneath piston 5. During the return stroke of piston 5 and rod 6 under gravity and assisted by a spring 16, oil passes from a vented transparent reservoir 10 mounted on end plate 3 along an axial bore 6c of rod 6 and past a check valve 15, and at the end of the return stroke air bubbles in the oil escape through an annular channel 9 formed between a seal 3<SP>1</SP>c and the tapered end of the rod 6. Air having leaked past a piston seal 5a is vented through a radial bore 5c and the axial bore 6c. In a modification the upper end of the cylinder 19 Fig. 6 is closed by axially spaced end plates 30, 300 which afford limited axial movement of an annular valve member 150 having an inner leaktight sealing ring 151 engaging the piston rod 60, a ring 156 which when member 150 is in its upper position seals against the end plate 300, and splined portions 152, 153 which when ring 156 is unseated by abutment of member 150 by a ring 140 on the free end of rod 60 provides a passage for reservoir oil to flow into cylinder chamber 80.