GB190013909A - Improvements in Direct Acting Pumping Engines. - Google Patents

Abstract

13,909. May, W., and Pulsometer Engineering Co. Aug. 2. Valve gear, combined fluid and tappet actuated, for direct-acting pumps. All the steam used passes from the inlet through the chamber of the pilot valve 1, and is directed by this valve through the passage 4 or 5 to the chamber 6 of the main valve, which directs the steam through the passage 10 or 11 to one or the other end of the main cylinder, or high-pressure cylinder in the case of a compound engine. The valve 1 is moved through a lever 16 pivoted at one end to the main valve spindle, and at the other to a tappet, which may take the form of a rod 19 moved by the contact of the high and low pressure pistons with its opposite ends. Near the end of a stroke, say the downward stroke, the lever 16 is moved by the rod 19 about the point 17<a>, thus shifting the valve 1 so as to cut off the steam from the upper ends of the main piston and main valve, and admit steam to the lower end of the main valve. On the further motion of the main piston, the cut-off steam expands, and a difference in pressure on the ends of the main valve is thus produced, which, together with the further movement of the rod 19, reverses the main valve. Thus all the steam used in shifting the main valve is used on the high-pressure side of the main piston. The valves may be of the double piston form shown, and the exhaust passage 22 from the high-pressure main piston and main valve may lead to a similar valve controlling the low-pressure supply. The end areas of the rod 19 may be so proportioned that the steam pressure thereon assists in the movement of the valves.