You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
     As a result of the prosperity and progress of the present industrial and commercial activities, the flush toilet has become indispensable in homes and apartments. The use of a large number of toilets, many of which are flushed many times everyday has caused a serious water supply problem, especially during energy crisis periods; the water being an expensive commodity. Now, all conventional flush toilets are usually operated by pressing a lever, which pulls a chain or the like to open a water outlet permitting water to flow from a tank for flushing. Usually, the water level in the water tank is controlled with a ball buoy. Whenever pressing the lever once, a volume of several liters of water will be flushed away; such case would be considered a waste during only releasing a urine. By the rate of flushing decades of liters of water each day, the volume of water to be flushed by the people of the whole world would be a surprising figure. 
     In case of a drought season appearing, water crisis will be resulted. Further, in the conventional flush toilet, the chain in the water tank is liable to be broken because of daily pulling tension to cause the lid unable to tightly close the water stop outlet; consequently, a water leak, which is another way of wasting the water, often results in addition to often required repair work. It is apparent that the conventional flush toilet is not practical in use because of wasting water. Moreover, the water stop lid in the conventional flush toilet is made of rubber in conic shape and hollow in its core; it is usually pulled with a cord to flush the water, and also is liable to cause a leak from the rift as a result of a loosing cord; therefore, it may be deemed as a bad product. 
     SUMMARY OF THE INVENTION 
     In view of the drawbacks of the conventional flush toilet equipment, the present invention is directed to a new water control device for flush toilet, of which the main feature is that the operation is done by means of a cam on the main axle coupling to an actuating rod, and the hydraulic control device so as to have the actuating axle controlling the actuating rod of a level to control the flushing of water in different phases in an appropriate volume. 
     Another feature of this invention is that in the hydraulic cylinder, a spring and a piston are furnished, and on the piston, a connecting rod is fixedly attached, and is coupled to a main axle so as to push the piston and the spring down to a given point; then, the spring will stretch upwards to push the piston so as to actuate the lever to push the actuating rod downwards to tightly close the water outlet without leaking. 
     A further feature of this invention is that the actuating rod comprises two sections which are connected together with a connecting sleeve. The upper end of the actuating rod is hooked into a hole at the front end of the lever, and the lower end of it is hooked to the water stop lid. The actuating rod is actuated with the actuating axle thru the lever to directly open/close the water stop lid quickly and stably without breaking, and loosing. 
     A still further feature of this invention is that the round pad having scales on the axle seat can show a user by rotating the handle to a scale desired so as to control the water volume to be flushed by a pre-determined time thru said round sliding cam of the main axle, and the piston in the hydraulic cylinder. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows an exploded view of the structure of this invention. 
     FIG. 2 shows an exploded view of the hydraulic device in this invention. 
     FIG. 3 shows an outer view of this invention. 
     FIG. 4 shows the invention installed in a toilet in the presently preferred manner. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIG. 1, there is provided a box (1) which is a hollow rectangular body, of which the outer surface is mounted with a square base (2); in the central hole of said base, an axle seat (3) with threads (4) is fitted, extending outwards. A round pad (5) with a calibration scale on the surface thereof is sleeved over said axle seat (3) and is fixedly attached to said seat with a nut. The handle (10) is fitted on the notch stud (12) at the front end of said main axle (11). At the upper left of said square base (2), a thru hole (7) is furnished on said box (1) for mounting a round salient block (21) at the front end of an actuating axle (20). 
     The front end of main axle (11) forms notch stud (12) being fitted into axle seat (3), and salient piece (13) at the rear portion of main axle (11) having a small hole (14) is coupled to a connecting rod (16) with a pin (15) thru small hole (14) and round hole (17) on rod (16). At the rear portion of main axle (11), a round sliding cam (18) having a catch flange (19) at one side, and having a catch piece (8) at the opposite side of catch flange (19); at the rear tip of axle (11), a round salient piece (9) is fitted into a round hole (31) on box bottom (30). 
     The front tip of actuating axle (20) forms round salient piece (21) for fitting into the thru hole (7). At the right side of axle (20), a supporting piece (26) having a ctach slot (22) under its front tip is furnished, and at the left side of axle (20), a catch piece (23) is furnished; the rear end having a round hole (24) of axle (20) forms into a round rod (25), which is fitted into the round hole (32) on the box bottom (30). 
     The lever (40) is a long strip with the front end being formed into a bent piece (41) having a round hole (42), and with a large round hole (43) at the front end and two round holes (44, 45) at the rear end. Said lever (40) is fixed to said round rod (25) by having rod (25) passing thru large round hole (43), and by using a screw (46) to fit thru round holes (42) and (24). 
     An actuating rod (50) includes two sections, of which the upper end of the front section forms into a catch hook (51) for hooking into the round holes (44,45) of lever (40), and the lower end of front section of said rod (50) is furnished with threads so as to connect, by screwing leftwards, to the top of a connecting sleeve (53). The rear section of rod (50) has threads (54) on the top thereof for connecting, by screwing rightwards, to the bottom of sleeve (53), and the other end of the section is hooked to the water stop lid (81) (see FIG. 4). The whole length of rod (50) may be adjusted by adjusting the length of the two sections screwed into the connecting sleeve (53). 
     Box bottom (30) is a rectangular thin plate, on which two round holes (31,32) and a small salient block (33) are furnished. The hydraulic control assembly of this invention comprises a hollow hydraulic cylinder (60), in which a spring (61) and a piston (62) with oil seal (63) are furnished. 
     On the top of cylinder (60), a rubber lid (64) is provided. The connecting rod (16) goes thru the round hole (65) of said rubber lid (64) and the round hole (66) of the piston (62) so as to have the small hole (29) on the connecting rod (16) coincided with the small hole (67) of said piston (62), and being penetrated with the pin (68) for fixing the connecting rod (16) and the piston (62) together. 
     FIG. 2 shows the exploded view of structure of the hydraulic control assembly. Inside the hydraulic cylinder (60), a ring flange (70) is furnished, and from ring flange (70) to the top portion of said cylinder (60), a little play is maintained between piston (62) and the inner wall of cylinder (60), while in the portion of cylinder (60) from ring flange (70) to the bottom of the cylinder, there is no play. A round salient piece (71) on the top of said piston (62) has an oil outlet (72); an oil inlet (73) is furnished vertically on the flat surface of said piston (62), and in the central round hole (65), a steel ball (69) is ftted as a check valve. 
     FIG. 3 shows the outer view of this invention. When it is completely assembled with all the components as shown in FIGS. 1 and 2, it will be tightly sealed. For use, it is necessary to press the handle (10) to rotate main axle (11); at the same time, the catch flange (19) of cam (18) disengages from the catch slot (22) of the actuating axle (20), and cam (18) surface will slowly rotate counter-clockwise; then, connecting rod (16) attached to the salient piece (13) of the main axle (11) will push the piston (62) in hydraulic cylinder (60) downwards to press the spring (61). Now, the hydraulic fluid in the hydraulic cylinder (60) will push steel ball (69) moving upwards and will flow out of oil outlet (72) and enter into the top portion of hydraulic cylinder (60). Upon said spring (61) stretching upwards, the piston (62) will move upwards, and the hydraulic fluid will, thru the oil inlet (73), flow into the empty portion under piston (62). Simultaneously, the connecting rod (16) will drive the main axle (11) and actuate cam (18) to rotate clockwise till the top of connecting rod (16) touches the catch piece (23) of the actuating axle (20), and till the catch flange (19) engages with the catch slot (22) of the supporting piece (26). As soon as the piston (62) inside the hydraulic cylinder (60) moves from the portion below the ring flange (70) over the ring flange, it will raise rapidly as a result of having play with the inner wall surface of cylinder (60). Such rapidly raising force will cause the lever (40) turning downwards to actuate the actuating rod (50) pushing downwards so as to close the water stop lid (81). 
     FIG. 4 shows the embodiment of this invention being installed in the water tank (80) of a flush toilet. As shown in the preceding Fig., box (1) is installed inside the water tank (80) with the handle (10) being left outside the tank (80). The actuating rod (50) is connected the water stop lid (81), which is a solid piece of rubber. 
     Since this invention is designed to flush the water in four different phases, as shown by the calibration scale on round pad (5), within ten seconds, each phase will last for 2.5 seconds, and the hydraulic fluid that is pumped above said piston (62) will just flow back within ten seconds. The calibration marks shown on said round pad (5) are 2.5 seconds in the first phase, five seconds in the second phase, 7.5 seconds in the third phase, and ten seconds in the 4th phase. When the user turn handle (10) to the first scale (2.5 seconds), the supporting piece (26) of said actuating axle (20) will rotate as a result of being driven by cam (18) to move the lever (40) upwards and to pull the actuating rod (50) to open water stop lid (81) for flushing; simultaneously, the fluid flowed out of the oil outlet (72) will, thru the oil inlet (73), flow back, and the piston (62) caused by the rebounding force of the spring (61) will pull the connecting rod (16) backwards to rotate the main axle (11), which will actuate said actuating axle (20) rotating reversely to cause the lever (40) moving downwards so as to have the actuating rod (50) pressing the water stop lid (81) for closing the water outlet. By the same theory, said device will operate in the rest phases; upon the time of each phase being up, the water will automatically be closed. For example, during urine discharging, the user may just rotate the handle to the first or second phase scale; during moving the bowel, the user may rotate the handle to the third or 4th phase scale. Such phase flushing method will fulfil the purpose of saving water.

Summary:
This invention relates to a &#34;Water Control Device for Flush Toilet&#34;. The water may be flushed in several phases thru the control means, which comprises a hydraulic control assembly, the actuation between the main axle and the actuating axle, a lever, and a actuating rod to control a water stop lid for water saving purpose.