GB190606185A - Improvements in or relating to Hydraulic Presses. - Google Patents

Abstract

6185. AndÚ, F. March 15, 1905, [date applied for under Patents Act, 1901]. Delivery, regulating.- In connexion with the supply of fluid pressure to hydraulic presses by low-speed pumps, the suction valves of the latter are operated at intervals so that communication may be made between the supply tank and pump or ram cylinder for the purpose of rendering the movement of the rams independent of the movement of the pump piston at any given time. Fig. 1 shows a sectional view of a press, the tank 12 of which is connected to the pump 2 or the rams 1 by the pipes 20, these being provided with a valve 3 which automatically closes during the discharge stroke of the pump. The valve may, however, be raised and held open by the roller 5 on the cross-head 4 acting on the adjustable cam 8 mounted on the rod 7, which is pivoted to the levers 6. The valve 3 is thus held open while the crank passes over the arc x y, and during this time the rams remain at rest and the table of the press is rotated. In one modification, the cross-head is connected directly to the lever 6 of the spindle 9. A modified form of apparatus for operating the cam 8 during the working of the machine is shown in Fig. 3. In the form shown in Fig. 5, two mechanically-operated valves 3, 30 are shown between the ram and the pump. Cams 24, 25 worked from the crank-shaft operate the valves through weighted levers 26, 27. In the form shown, the cam-disks make one complete revolution to each three strokes of the pump. The object of this is to raise the ram by steps in accordance with the curve shown in Fig. 6. In a modification of this apparatus, the valve 30 is arranged so as to be automatically closed by the pressure in the ram cylinder. In the form shown in Fig. 8, communication is established between the pump cylinder and the tank by means of the cam disks 24, 25 and the valves 3, 30 at the moment of highest pressure so that at that movement only a piston 100 of smaller diameter exercises the pressure required, so that smaller power is required for the same speed of working.