Technical Field

Technical Field

[1] The present invention relates generally to a rainwater collection and dispensation system for a building, comprising at least a water pump, at least a rainwater storage tank, as well as interconnecting pipes, fittings and electrical controls. It relates particularly to an automatic rainwater collection and dispensation system further comprising at least one main unit, including a water pump control unit and a rainwater reservoir, disposed in-line to a cut-off section of a gutter to provide a time delay to start pumping.

Background Art

Background Art

[2] Many past efforts were made to collect and store rainwater for non-drinking

purposes, such as flushing water closet, gardening and washing.

[3] United States Patent Number 6,941,702 discloses a rainwater collection and dispensation system for economically conserving water usage by using collected rainwater. The system includes a gutter being adapted to be mounted along an edge of a roof of a building structure; and also includes a tank support member being adapted to rest upon a ground and being disposed beneath a portion of the gutter; and further includes a tank being securely and removably supported upon the tank support member; and also includes a drainage spout interconnecting the gutter and the tank for draining rainwater from the gutter into the tank; and further includes a rainwater dispensing assembly including an overflow pipe member being disposed through a wall of the tank for draining rainwater from the tank.

[4] This prior art invention essentially allows rainwater from gutters to fall by gravity to a storage tank below. The main disadvantage of this prior art gutter collection system is that the pressure head allowed by the storage tank is limited. A pump is required to dispense rainwater from the storage tank. Furthermore, the tank may be visibly large, thereby affecting the aesthetics of a building property.

[5] United States Patent Application Publication Number 2008/0128030 discloses

systems and methods for the collection, retention and redistribution of rainwater, which make use of building foundations and surface concrete slab structures. A variety of rainwater collectors are anticipated, including rooftop collection systems (e.g.

gutters) and ground surface covering structures (e.g. driveways, sidewalks, parking lots and patios). These collection systems are joined together in a collection conduit system that carries the rainwater to one or more rainwater containment vessels. The stored water may then be redistributed, again through a variety of distribution means, to address part or all of the landscape watering requirements of the property. The system takes advantage of standard foundation and slab construction techniques to establish a major portion of the structure required for the containment vessel. The main disadvantage of this ground or underground system is that practically little or no pressure head is available and a pump is required to dispense the rainwater collected.

Summary of the Invention

[6] A primary object of the present invention is to collect rainwater from the gutters along the bottom edges of roofs of a building after a flush of rainfall; and after a time delay, to start pumping the collected rainwater to a rainwater storage tank; and to stop pumping when there is insufficient rainwater in the rainwater reservoir or the rainwater storage tank is full.

[7] A second object of the present invention is to render operations of the rainwater collection and dispensation system fully automatic with electrical controls.

[8] A third object of the present invention is to indicate the status of the system operations on a main switch panel installed inside a building.

[9] A fourth object of the present invention is to ensure rainwater collected in a rainwater reservoir is clean and free from debris.

[10] Other objects will become evident following the description given below.

[11] These and other objects are achieved by an automatic rainwater collection and dispensation system with at least one water pump, at least one rainwater storage tank, as well as interconnecting pipes, fittings and electrical controls, further comprising at least a main unit including a water pump control unit and a rainwater reservoir. The main unit is disposed in-line to a cut-off section of a gutter along the bottom edges of the roof of a building adjacent to a vertical down pipe to an open drain. The rainwater storage tank is disposed under the roof of the building. Inlet pipe connects the main unit to the rainwater storage tank. Rainwater in the rainwater reservoir can then be pumped to the rainwater storage tank through this inlet pipe. Outlet pipe from the rainwater storage tank allows the collected rainwater to be used in other parts of the building for non-drinking purposes.

[12] The water pump is preferably operable by a water pump control unit comprising at least one floating means with the assistance of electrical controls, whereby the water pump, after a time delay, starts pumping when there is sufficient rainwater in the rainwater reservoir and the rainwater storage tank is not full, and the water pump stops pumping when there is insufficient rainwater in the rainwater reservoir or the rainwater storage tank is full. [13] The rainwater storage tank compliments an existing tap water storage tank disposed under the roof of the building by interconnecting pipes, fittings and electrical controls. Brief Description of the Drawings

[14] In order that the present invention may be more readily understood, the following description is given, by way of example, of an automatic rainwater collection and dispensation system made in accordance with the present invention. Reference will be made to the accompanying drawings, in which:

[15] Figure la shows a side cross-sectional view of a double-storey building, with two main units of the present invention disposed in-line to cut-off sections of gutters, and a rainwater storage tank complimenting an existing tap water storage tank disposed under the roof of the building.

[16] Figure lb shows a front view of a double-storey building, with one main unit of the present invention disposed in-line to a cut-off section of a gutter and adjacent to a vertical down pipe via a bend pipe to an open drain.

[17] Figure 2a shows an enlarged view of a main unit of the present invention disposed in-line to a cut-off section of a gutter and adjacent to a vertical down pipe via a bend pipe, the main unit and the bend pipe being connected with a horizontal bypass pipe.

[18] Figure 2b shows a partial cross-sectional end view of the main unit, as in Figure 2a, including a water pump control unit.

[19] Figure 2c shows a top view of a main unit laden with two filtering plates and a water pump control unit with top cover.

[20] Figure 2d shows a top view of the locations of the water pump control unit without top cover and a water pump, after removing the filtering plates.

[21] Figure 3a shows a perspective view of a first embodiment of the water pump control unit as shown in Figure 2d, with a seesaw lever arm in a lifted position.

[22] Figure 3b shows a cross-sectional view of the first embodiment of the water pump control unit, with the seesaw lever arm in a lifted position.

[23] Figure 4a shows a perspective view of the first embodiment of the water pump

control unit as shown in Figure 2d, with the seesaw lever arm in a closed position.

[24] Figure 4b shows a cross-sectional view of the first embodiment of the water pump control unit, with the seesaw lever arm in a closed position.

[25] Figure 5 shows a perspective view of a second embodiment of the water pump

control unit, with a seesaw lever arm in a lifted position.

[26] Figure 6 shows a cross-sectional side view of a rainwater storage tank connected to an existing tap water storage tank partially shown, along with electrical controls to make the present invention fully automatic.

[27] Figure 7 shows an example of a main switch panel for indicating status of the system operations of the present invention. [28] Figure 8 shows an example of a circuit diagram depicting the electrical controls to render the present invention fully automatic.

Disclosure of Invention

Detailed Description

[29] Prior art inventions simply allow rainwater from gutters to fall by gravity to a ground or underground storage tank. A water pump is later used to dispense rainwater around a building. It is obvious that the water pump consumes more power.

[30] A building can have more than one gutter (20) along the bottom edges of a roof. A rainwater collection and dispensation system comprises at least one water pump (11), at least one rainwater storage tank (30), as well as interconnecting pipes, fittings and electrical controls. According to the present invention, a section of the gutter (20), adjacent to a vertical down pipe (50) to an open drain (70), is cut to accommodate a main unit (10) disposed in-line with the gutter. The main unit (10) includes a water pump control unit (12) and a rainwater reservoir (13). Rainwater is then collected from the edges of the roof. It is important to collect only clean rainwater without debris. Time delays to start pumping are therefore provided by technical features in the present invention to ensure rainwater collected is debris free. The water pump (11) can be disposed inside or outside the main unit (10). The water pump (11) starts to pump rainwater in the rainwater reservoir (13) to the rainwater storage tank (30), after a time delay, when there is sufficient rainwater in the rainwater reservoir (13) and the rainwater storage tank (30) is not full.

[31] Interconnecting pipes and fittings common to existing plumbing practices are

included in the drawings. They are not however discussed in detail, so as to keep the description simple and straightforward.

[32] Electrical controls render the present invention fully automatic.

[33] Essentially, the present invention teaches the best operating mode of an automatic rainwater collection and dispensation system for a building.

[34] In Figure la, two main units (10) of the present invention are disposed in-line with the gutters (20) under the bottom edges of two roofs of a double-storey building.

According to the invention, some rainwater is pumped to a rainwater storage tank (30). The rainwater storage tank (30) of the present invention compliments an existing tap water storage tank (40) disposed under the roof of the building. Excess rainwater from the gutters (20) travels along the vertical down pipes (50) to the open drains (70). Outlet pipes (32, 42) from the two storage tanks (30, 40) are connected to water closets and taps in the building.

[35] In Figure lb, a section of the gutter (20), adjacent to the vertical down pipe (50) to the open drain (70), is cut to accommodate a main unit (10) disposed in-line with the gutter. The depth of the main unit (10) is larger than the depth of the gutter (20). The extra depth forms a space for the rainwater reservoir (13) therein. The space above the rainwater reservoir (13) constitutes a gutter section.

[36] In Figure 2a, the main unit (10) of the present invention is disposed in-line to a cutoff section of the gutter (20) and adjacent to the vertical down pipe (50). A horizontally disposed bypass pipe (52) is connected through an opening provided at the base of the main unit (10) to a bend pipe (51). After a flush of rainfall, most rainwater will travel along the gutter (20) at a first flow rate. Some rainwater will fall by gravity and enter the rainwater reservoir (13). Rainwater in the rainwater reservoir (13) also exits at a second flow rate through the bypass pipe (52) to the bend pipe (51) and ultimately to the vertical down pipe (50). The second flow rate is the rate of effluence from the rainwater reservoir (13). The diameter of the bypass pipe (52) also determines this rate of effluence. The time delay to start pumping is thus controlled by the difference between the rate of entry of rainwater into the rainwater reservoir (13) and the rate of effluence from the rainwater reservoir (13). Eventually rainwater will be accumulated in the rainwater reservoir (13) if the first flow rate is greater than the second flow rate. This rising rainwater level will activate electrical controls to switch on the water pump (11). One purpose for this time delay is to allow initial rainwater with debris after a first flush of rainfall to travel down the vertical down pipe (50).

[37] In Figure 2b, the water pump control unit (12) is disposed on one side of the main unit (10) of the present invention. The water pump control unit (12) does not block off the rainwater passage of the gutter (20). Most rainwater in the gutter (20) travels to the vertical down pipe (50) through the bend pipe (51) and fittings. An inlet pipe (31) to the rainwater storage tank (30) is connected from the rainwater reservoir (13) of the main unit (10). An overflow pipe (33) from the rainwater storage tank (30) is connected to the vertical down pipe (50).

[38] In Figure 2c, at least one filtering plate (19) carrying perforation holes covers the opening of the rainwater reservoir (13). This filtering plate (19) is disposed intermediately of the depth of the main unit (10). When rainwater from the gutter (20) falls down by gravity to the rainwater reservoir (13), the filtering plate (19) prevents debris from falling through to the rainwater reservoir (13). The water pump control unit (12) is substantially trapezoidal in shape, with two sloped ends. It is disposed on one side of the main unit (10), extending from the rainwater reservoir (13) to the gutter section above. The water pump control unit (12) is substantially open at its top and bottom sides and includes a chamber (18) and an enclosure (17). The bottom of the chamber (18) is open to allow rainwater in the rainwater reservoir (13) to rise therein. The top sides of the chamber (18) and the enclosure (17) can be closed with a cover (not shown). The water pump control unit (12) is therefore partly or fully immersed in the rainwater reservoir (13) of the main unit (10), extending to the gutter section above. The sloped ends of the water pump control unit (12) allow rainwater in the gutter (20) to flow by with minimal blockage. Debris including leaves and the like will not be collected therein. A water outlet connector (34) connects the main unit (10) to the rainwater storage tank (30) via the inlet pipe (31).

[39] In Figure 2d, the filtering plates (19) are removed from the opening of the rainwater reservoir (13). At the base of the water pump control unit (12), there is a seesaw lever arm (15). Its free end is a round cover which is used to cover an opening connecting to the bypass pipe (52) underneath the main unit (10). It is important to note that this round cover does not completely seal off the opening. It is advantageous to incorporate a small gap or a hole therein, to allow a small volume of rainwater to seep through. It affects the effluence rate of rainwater to the bypass pipe (52) and hence the time delay to start pumping to build up rainwater in the rainwater reservoir (13). When rain stops, rainwater in the rainwater reservoir (13), the chamber (18) and the enclosure (17) eventually leaks through to the bypass pipe (52). A filtering basket (14) covers the inlet of the water pump (11), to prevent passage of debris into the water pump (11).

[40] In this drawing, the water pump (11) is disposed inside the rainwater reservoir (13).

It is important to note that the water pump (11) can also be disposed outside the main unit (10). In this situation, a suction pipe from the outside water pump (11) can be employed to pump rainwater from the rainwater reservoir (13).

[41] According to the teaching of the present invention, two embodiments of the water pump control unit (12) will be described here below. The water pump control unit (12) includes a chamber (18) and an enclosure (17). The water pump control unit (12) is disposed towards the gutter section, therefore leaving some empty space below. Two floating means (181, 171) are employed in both the first and second embodiments.

[42] The bottom of the chamber (18) is substantially open. The chamber (18) provides a time delay to start pumping. The first floating means (181) is integrally fitted with a first top rod (183) and a bottom rod (182) and moves up and down in the chamber (18) with the assistance of vertical guides (16). The first top rod (183) engages a first overhead limit switch (121) when rainwater rises in the chamber (18). The bottom rod (182) of the first floating means (181) is engaged to a seesaw lever arm (15), with the assistance of a hinge bar (184). The free end of the seesaw lever arm (15) is the round cover, which can loosely close off the opening connecting to the bypass pipe (52). Hence, the time delay to start pumping is also affected.

[43] The enclosure (17) further affects the time delay to start pumping. The second

floating means (171) therein moves up to engage a second overhead limit switch (122) when there is sufficient rainwater being accumulated in the enclosure (17). When there is insufficient rainwater, the second floating means (171) stays down due to its own weight inside the enclosure (17).

[44] Figure 3a shows a perspective view of the first embodiment of the water pump

control unit (12) as shown in Figure 2d, with the seesaw lever arm (15) in a lifted position.

[45] Figure 3b is a cross-sectional view of the first embodiment of the water pump control unit (12) with the seesaw lever arm (15) in a lifted position. This corresponds to a situation when there is no or insufficient rainwater in the rainwater reservoir (13) and the chamber (18). It also shows the dispositions of the water pump (11) and the water pump control unit (12); two overhead limit switches (121, 122), two floating means (181, 171) and one seesaw lever arm (15) engaging the first floating means (181).

[46] The chamber (18) incorporates the first floating means (181) which is integrally

fitted with a first top rod (183) and a bottom rod (182). The first floating means (181) is constrained to move up and down, with the assistance of vertical guides (16) therein. Above the first floating means (181), there is disposed the first overhead limit switch (121). Below the first floating means (181), there is also disposed the seesaw lever arm

(15) . The free end of the seesaw lever arm (15) is the round cover, which can loosely close off the opening connecting the bypass pipe (52). The other end of the seesaw lever arm (15) is engaged to the bottom rod (182) of the first floating means (181), with the assistance of the hinge bar (184). When there is no or insufficient rainwater in the chamber (18), the first floating means (181) stays down due to its own weight. The bottom rod (182) pushes the engaged end of the seesaw lever arm (15) downward. The round cover at the other free end of the seesaw lever arm (15) is lifted off the opening connecting to the bypass pipe (52).

[47] The enclosure (17) incorporates the second floating means (171) which is integrally fitted with a second top rod (172). The second floating means (171) is also constrained to move up and down inside the enclosure (17), with the assistance of vertical guides

(16) therein.

[48] In one mode of operations, a first opening (173) is provided towards the bottom side or base of the enclosure (17). Figure 4a shows a perspective view of the first embodiment of the water pump control unit (12) as shown in Figure 2d, with the seesaw lever arm (15) in a closed position. Figure 4b shows a cross-sectional view of the first embodiment of the water pump control unit (12) with the seesaw lever arm (15) in a closed position. This corresponds to a situation when there is sufficient rainwater in the rainwater reservoir (13) and the chamber (18). When there is rainwater accumulated in the chamber (18), the first floating means (181) moves up by buoyancy. The first top rod (183) engages the first overhead limit switch (121). The bottom rod (182) lifts the engaged end of the seesaw lever arm (15) upward with the assistance of a hinge bar (184). The round cover at the other free end of the seesaw lever arm (15) is pushed down and loosely closing off the opening connecting to the bypass pipe (52). As more rainwater is accumulated in the chamber (18), excess rainwater enters the enclosure (17) through the first opening (173). The second floating means (171) then moves up by buoyancy. Its top rod (172) engages the second overhead limit switch (122).

[49] Only with the first overhead limit switch (121) and the second overhead limit switch (122) are engaged, the electrical controls will activate the water pump (11) which starts pumping rainwater accumulated in the rainwater reservoir (13) through the inlet pipe (31) to the rainwater storage tank (30). With either one of the two overhead limit switches (121, 122) disengaged, the water pump (11) will stop pumping.

[50] In other words, the rainwater reservoir (13) and the chamber (18) provide firstly a time delay to start pumping. The enclosure (17) secondly extends the time delay to start pumping. The location of the first opening (173) and its diameter on the enclosure (17) also affect the time delay to start pumping.

[51] Figure 5 shows a perspective view of a second embodiment of the water pump

control unit (12) in another mode of operation. Here, the first opening (173) in the enclosure (17) is disposed on a higher level. With this increase in height or position, a longer time delay to start pumping is introduced because rainwater takes time to fill up to this level. The second floating means (171) takes a longer time to engage the second overhead limit switch (122). In order to drain off the rainwater in the enclosure (17), a second opening (174) is disposed at the bottom side or base of the enclosure (17). A third floating means (175) with a closure means is provided to engage or disengage the second opening (174).

[52] It is important to note that a variant of the above first and second embodiments of the water pump control unit (12) is to use only one floating means (181). This variant is less efficient but is still workable. Another less efficient variant is not to use the seesaw lever arm (15) at the bottom of the first floating means (181).

[53] As seen in Figure 6, the rainwater storage tank (30) of the present invention is

connected to an existing tap water storage tank (40), along with electrical controls to make the invention fully automatic.

[54] The inlet pipe (31) from the main unit (10) of the present invention is disposed on a higher level of the rainwater storage tank (30). The section of the inlet pipe (31) adjacent to the rainwater storage tank (30) is disposed with a magnetic flow switch (35) which detects the presence of rainwater and switches on a status light in a main switch panel (60). The inlet pipe (31) is further incorporated with two units of nonreturn check valve to prevent back flow of the rainwater to the main unit (10) of the present invention. A ball valve (39) is fixed before the magnetic flow switch (35). The ball valve (39) along with a union joint (36) closes the main unit (10) for easy release of the pipe work, in case there is a need to change the main unit (10). [55] The outlet pipe (32) from the rainwater storage tank (30) and the outlet pipe (42) from the tap water storage tank (40) are joined together with a Tee joint (41) to supply water to the water closets and taps in the building. An automatic electrical control valve (43) is disposed at the outlet pipe (42) of the tap water storage tank (40). This automatic electrical control valve (43) is set at an off-position and is operable by alternating current (AC) or direct current (DC). The outlet pipes (32, 42) are fitted with standard fittings commonly known in the plumbing practice, including ball valve, union joint, strainer, check valve and the like.

[56] At least one overflow pipe (33) is also disposed on another high level of the

rainwater storage tank (30) and it is connected to the vertical down pipe (50) to the open drain (70). Interconnecting pipes and fittings needed are well-known according to current plumbing practice.

[57] When water level in the rainwater storage tank (30) is low, the electrical controls automatically switch over to water supply from the tap water storage tank (40). When water level in the rainwater storage tank (30) reaches such pre-determined level, the system reverts. A magnetic floating limit switch (37) is disposed inside the rainwater storage tank (30) at a high level. When water is detected at this full level, the magnetic floating limit switch (37) will switch off and cut-off power supply to the water pump (11). When water is not detected, the magnetic floating limit switch (37) is switched on and the water pump (11) is ready in a stand-by mode. The water pump (11) starts pumping when both the overhead limit switches (121, 122) to the first and second floating means (181, 171) respectively are both engaged.

[58] A submersion floating magnetic level switch (38) is disposed inside the rainwater storage tank (30) at a low level. When water level is above this low level, this submersion floating magnetic level switch (38) will be de-activated and switched off. When water level is lower than this low level, it is switched on and the automatic electrical control valve (43) disposed at the outlet pipe (42) of the tap water storage tank (40) is switched on. Tap water is then to be used. The status of rainwater presence in the rainwater storage tank (30) is thus sensed by the submersion floating magnetic level switch (38); and this status is transmitted accordingly.

[59] It is important to note that the rainwater storage tank (30) and the tap water storage tank (40) are disposed under the roof, at high position from the ground. This location provides pressure head to rainwater collected so that it is dispensed essentially by gravity. No water pump is required.

[60] The rainwater storage tank (30) is preferably made from metal including stainless steel and press steel, or plastic material including fibreglass and low-density polypropylene (LDPE). The rainwater storage tank (30) can also be formed from a plurality of smaller containers with interlocking and interconnecting pipes. This ar- rangement allows existing buildings to install the invention without removing roof trusses or ceilings. The rainwater storage tank (30) and all inlet and outlet pipes (31, 32) and fittings are painted in green colour or made with green pigments. Stopcocks and taps also carry green colour labelling or lettering. This is to create an identity to the invention.

[61] As seen in Figure 7, the main switch panel (60) is installed inside a building. It

indicates the status of system operations of four main units (10) of the present invention. Different lights are employed to indicate different status of the invention. (Exact colour scheme of the lights can be changed in actual practice.) When the main switch (MS-1) is switched on, an active red neon light indicates that the system is on a stand-by mode ready to operate. An active orange LED light indicates that the water pump (11) in the rainwater reservoir (13) is pumping rainwater. An active green LED light indicates that rainwater is flowing into the rainwater storage tank (30). An active blue LED light indicates that water supply is from the tap water storage tank (40).

[62] In order to indicate the status mentioned above, Figure 8 shows an example of a circuit diagram depicting the electrical controls to render the invention fully automatic. These electrical controls are operable by 110 V or 230 V alternating current (AC) or direct current (DC). An AC to DC adaptor complete with short circuit protection features and fuses is incorporated to protect the invention for safety purposes. This AC to DC adaptor is placed inside an AC and DC power supply unit (123) placed under the roof of the building near the rainwater storage tank (30) . Once the main switch (MS-1) is switched on, the red neon light is lighted and the supply of 12 V or 24 V direct current is ready. When the water level is low in the rainwater storage tank (30), a magnetic floating limit switch (37 or MFLS-2) is switched on and is on a stand-by mode. This is in turn linked to a first overhead limit switch (121 or LS-3) and a second overhead limit switch (122 or LS-4). The first overhead limit switch (121 or LS-3) is disposed above the first floating means (181) and the second overhead limit switch (122 or LS-4) is disposed above the second floating means (171).

[63] When there is no rain or the rainwater reservoir (13) is without rainwater, the first overhead limit switch (121 or LS-3) and the second overhead limit switch (122 or LS- 4) remain off. When it is raining, the first floating means (181) rises and activates the first overhead limit switch (121 or LS-3). This output line is connected to the second overhead limit switch (122 or LS-4) which is disposed above the second floating means (171). Only when raining continues and more rainwater is collected, this second overhead limit switch (122 or LS-4) will be activated. When this second overhead limit switch (122 or LS-4) is switched on, the magnetic coil of a delay switch-7 (DS-7) is switched on and the AC/DC water pump (11) is activated. Rainwater is then pumped from the rainwater reservoir (13) of the main unit (10) into the rainwater storage tank (30). LED lights 1/3/5/7 (in orange colour) will be lighted in the main switch panel (60). This indicates that the water pump (11) is working. Green light is indicated by LED 2/4/6/8 which are linked to the magnetic flow switch (35 or MFS-5) disposed on the inlet pipe (31) to the rainwater storage tank (30). This confirms that rainwater is indeed flowing through. Blue light is indicated by LED 9 when a delay switch-8 (DS-8) is switched on. Water supply is now from the tap water storage tank (40). It reminds the householders to conserve water.

[64] When there is electricity failure, the automatic electrical control valve (43) on the outlet pipe (42) of the tap water storage tank (40) will remain in "close" mode. If, at the same time, the rainwater storage tank (30) is empty, there will be no water supply to the building. It is therefore advantageous to incorporate a manual bypass to switch on the automatic electrical control valve (43) in that case.