Patent GB-943051-A (GB)
Title: An improved apparatus for automatically controlling the rate of discharge from a body of water impounded by a dam, weir or the like
IPC: E02B7/20
Filed: 1961-04-27
Abstract: 943,051. Sluice gates. L. A. TURNER. April 27, 1961 [April 29, 1960], No. 15250/61. Heading E1H. [Also in Division F2] The outflow of water from a weir is controlled by a gate 3, Fig. 1, actuated by the variable buoyancy of a hollow float 5 provided with an air vent 7, water inlet means 6 and conduit means which supply or withdraw water at rates dependent upon and controlled by the level in the weir. Water rises in the weir until it floods a vent 11 leading through a flexible conduit 12 to a main syphon 9 which is thus primed to cause the float 5 to drain through a flexible coupling 19 and an outlet pipe 20. The float thus gains buoyancy and rises until it engages an adjustable stop 8. When the water level falls sufficiently to uncover the vent 11 once more the action of the syphon 9 is broken so that the float re-floods through the inlet 6 and closes the gate 3. If the water level remains constant the syphoning action is broken by air entering the suction limb of the syphon. If the water level rises, however, a secondary syphon 10 becomes primed through a vent 13. The suction limb of the secondary syphon is lower than that of the main syphon so that the float remains buoyant in its raised position until the water level rises sufficiently to enter the air vent 7 and re-sink the float. The syphon may be fixed instead of moving with the gate and the two priming vents may be at the same level. In Figs. 3 and 4, a separate control chamber 25 with an inlet 6a is connected by a conduit 26 to the float 5 of a gate 3 in a channel 29, the main and secondary syphons 15a, 16a having primary vents 1 1a, 13a. Fig. 10, shows a further modification in which a control chamber 25a is connected to the float by a conduit 26a and has inlet and outlet valves 32, 35 controlled through levers 33, 36 and a link 38 by a screw-adjusted float 41. The syphons may also be replaced by the valve means of Fig. 11 in which an outlet pipe 44 and an inlet pipe 44a from the weir are controlled by valves 45 on a T-shaped lever 47 carrying a float 50 in the weir and a float 51 in the discharge channel. The latter float over-rides the action of the float 50 when the flow in the channel exceeds a predetermined value so that the inlet pipe 44a is opened and the flood flooded through a conduit 26a to cause the gate to close. In a still further arrangement, a control chamber is provided with a syphon having a priming vent in the weir and the lower end of its suction limb within the chamber controlled by a floatoperated valve. The flow through the syphon balances the flow from an inlet to the chamber until the level in the weir falls sufficiently to uncover the priming vent when the level in the control chamber rises to flood the float operating the gate. The float operated valve closes the suction limb of the syphon when the level in the control chamber falls after the gateoperated float has been drained. The invention may be applied to a vertically slidable gate by using a rack and pinion drive between the float pivot shaft and the gate.