4021. Bryan, A., and Mountfort, L. F. Feb. 17. Valves controlled from a distance.-In apparatus for controlling the flow of a large volume of liquid, such as that of sewage to bacteria beds, of the kind comprising hydraulic valveoperating means with an auxiliary pressurecontrolling valve or valves governed by a time element, the time element is adjustable or variable so that the intermittency of the opening of the main valve can be varied and is furnished with one or more cams which act directly on the pressure-controlling valve or valves. The invention is applicable in connexion with hydraulically-operated valves of the non-reversing rotary type and in connexion with rotary valves operated by a rotary hydraulic engine which is linked to them by a crank or crank-plate, a connecting-rod, and a one-way clutch mechanism such as is described in Specification 3699/12. In the form of apparatus shown in Fig. 2, the pressure-controlling device comprises two valve chambers b, c connected with the hydraulic-ram cylinder by pipes i<1>, j and with one another by tha passage j<1>. The valve b<3> being closed and the valve c<3> open, the pressure fluid from the main i is admitted through the pipe i<1> to lift the ram a' and give a working stroke to the plunger a<2> which opens the sewage valve. The upper portion of the cylinder a is connected to exhaust by the pipe j, passage j<1>, casing c, and pipe c<4>. When a cam e on a clock-driven time element d disengages from a tappet g, the tappet is turned by a spring h, and the positions of the valves b<3>, c<3> are reversed. The valve c<3> closes the connexion to exhaust, and the opening of the valve b<3> admits the pressure of the main i through the casing b and pipe j to the top of the cylinder a. The pressure on the top of the ram being greater than that below, the plunger then makes a downward idle stroke. The sequence of operations necessary to close the sewage valve is effected by means of a cam f, which is adjustable relatively to the cam e to allow of variation in the period of sewage discharge. Modified apparatus is described in which a single valve-casing b containing a piston or sleeve valve is used to connect the pipe j with the pressure main i and the exhaust alternately. Similarly a single casing may be used to make the connexions for pressure and exhaust with one end of the hydraulic cylinder when a single-acting ram making its return stroke under gravity is used. Fig. 9 shows a further alternative arrangement comprising an oscillating plug valve having a peripheral passage b<2> which in the two positions of the valve connects the pipe j with the pressure main i and the exhaust i<3> respectively. A time element which allows of variation in the period of flow may be constructed as shown in Fig. 3, a laterally-adjustable cylinder d being provided with differently spaced pairs of cams c, f. If the cams e are arranged to form a continuons helical rib, the lateral adjustment may be made automatically by means of levers operated by a float in the sewage mains or chambers. Instead of a rotary time element, a reciprocating slide with adjustable cams may be used. The frequency of the intermittent operation of the sewage valve may be varied by altering the speed of the time element. As shown in Fig. 3, the operating-motor m drives a shaft d<9>, which can be moved so that a spurwheel d<10> engages with any of a series of rings of teeth d<5>, d<6> on the face of a disk d<4> on the shaft of the time element. Alternatively, the motor may drive the time-element shaft directly, subject to the automatic control of a brake operated by a float in the sewage. An arrangement is described in which the time element, a cam of two diameters, is driven intermittently at the commencement of each flow and rest period. When the sewage valve is of the sliding penstock or gate type or of the reversing oscillating type and is connected with the hydraulic plunger so that the working and return strokes of the plunger respectively open and close the sewage valve, the time element may be formed as a stepped cylinder of two diameters d<1>, d<2>, Fig. 15, and the period of contact of the tappet or valve spindle with the two portions of the time element will correspond respectively to the open and closed periods for the sewage valve. A time element may be provided with cams suitable for giving an intermittent sewage flow with several comparatively short discharge periods followed by a longer period of rest. Laterally-adjustable cylinders with several such series of cams may be used. The same object is attained by the use of two cam-plates automatically brought into operative position, one of which determines the normal periods of discharge and rest, while the other is used to give the intermittency during the period of discharge. As shown in Fig. 2, the pipes j and i are provided with branches each of which may be connected with a hydraulic cylinder for the operation of separate sewage valves, the control apparatus being situated at a central station. When a rotary hydraulic engine is used, the cams are so formed that they remain in contact with the control-valve stem or tappet long enough to keep the engine running for the time required to effect the opening or closing of the main valve. The Provisional Specification also refers to the use of a vertically disposed cam cylinder which is lifted directly by a regulating- float, and also to a system of bacteria beds in which the valves supplying the beds have separate time-changing controls, and the compensation for fluctuations in the main sewer is effected by a float - operated arrangement common to all the valves.