Abstract:
A water saving device for use at or near a water outlet has a first water flow regulating element; a second water flow regulating element disposed downstream of the first regulating element; and a chamber formed between the first and second regulating elements. All of one or more water flow regulating parts of the second regulating element are made from substantially solid material.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates broadly to a water saving device for use at or near a water outlet. 
       BACKGROUND 
       [0002]    In former times, fresh water was freely available and was thought by some to be an inexhaustible resource. Many communities provided unlimited supplies of water to commercial and residential consumers at a very low cost. Thus, with water conservation having a low priority, little thought was given to it in the design of water-using appliances. 
         [0003]    Currently, a combination of factors such as rising urban populations, diminishing water tables and near drought condition in various parts of the world, have combined to diminish the amount of fresh water available to the public. In response to these factors, the public has become aware of the necessity and in some cases, the urgency of water conservation measures. In this regard, water rates are being implemented in many communities throughout the world. 
         [0004]    As a result of such water conservation efforts now taking place, both voluntarily and as a result of legislation, homemakers and business managers alike are actively seeking ways to conserve this precious resource. Manufacturers of water consuming appliances, such as taps, shower handles and dishwashers, are developing new products, which perform efficiently, while consuming less water than earlier models. As a result, new appliances are gradually replacing the older appliances, which may be phased out of service over about a ten year period, for example, this will result in significant water conservation. 
         [0005]    Several problems may be encountered when using the conventional water saving devices. One of the problems is that the water pressure out from the water saving devices is typically reduced as a result of reduced water flow. It would be desirable to minimise the reduction of water pressure for a given reduced water flow in order to maintain a perception of sufficient water flow for the consumer. 
       SUMMARY 
       [0006]    In accordance with an aspect of the present invention, there is provided a water saving device for use at or near a water outlet, the device comprising: a first water flow regulating element; a second water flow regulating element disposed downstream of the first regulating element; a chamber formed between the first and second regulating elements; wherein all of one or more water flow regulating parts of the second regulating element are made from substantially solid material. 
         [0007]    The chamber may separate the first and second regulating elements by a distance chosen such that a water force prior to the second regulating element has a desired value. 
         [0008]    The distance may be about ⅓ of a diameter of a water supply line for the outlet. 
         [0009]    The second regulating element may be mounted within the chamber in a substantially airtight manner under water flow. 
         [0010]    The device may further comprise one or more netting elements disposed downstream of the second regulating element. 
         [0011]    The first regulating element may comprise an array of holes. The number or holes may range from 1 to 4. 
         [0012]    The holes may be substantially circular in shape. The diameter of the holes may be from about 1.5 mm to 3 mm. 
         [0013]    The distance between the first and second water flow regulating elements may be adjustable. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]    Embodiments of the invention will be better understood and readily apparent to one of ordinary skill in the art from the following written description, by way of example only, and in conjunction with the drawings, in which: 
           [0015]      FIG. 1   a  shows a schematic cross-sectional view of a water saving device in an example embodiment. 
           [0016]      FIGS. 1   b ,  1   c  and  1   d  are schematic plan views of components of the water saving device of  FIG. 1   a.    
           [0017]      FIG. 2   a  and  2   b  are schematic drawings illustrating application of water saving devices according to example embodiments of the present invention being used in a water tap and in a shower head respectively. 
           [0018]      FIG. 3  shows a table illustrating a comparison in water flow and water pressure between an existing water saving device and a water saving device according to the example embodiments. 
       
    
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 1   a  shows the schematic diagram of the water saving device  100  in an example embodiment. The water saving device  100  comprises an enclosure  102 , an upper flow regulating structure  104 , a lower flow regulating structure  106  and a mesh socket  108 . In the example embodiment, the enclosure  102  is made of material such as chromed metal. The enclosure  102  has threads  101  around its inner circumference. The threads  101  start from a top end of the enclosure  102  and extend to about half of the height of the enclosure  102 . There is a rim  103  in the enclosure  102  near where the threads  101  end. The lower flow regulating structure  106  consists of a disk  113  and a ring housing  110 . 
         [0020]      FIG. 1   b  shows a plan view of the upper flow regulating structure  104  in an example embodiment. The upper flow regulating structure  104  has a circular protrusion  104   a  in the centre. There are two holes  104   b  aligned on a centre line on the surface of the protrusion  104   a  in the example embodiment. The two holes  104   b  extend from the surface of the protrusion  104   a  to the other side of the upper flow regulating structure  104 . There are threads (not shown) around the outer circumference of the upper flow regulating structure  104 . 
         [0021]      FIG. 1   c  shows a top view of the disk  113  of the lower flow regulating structure  106  ( FIG. 1   a ) in an example embodiment. The disk  113  is made of thermosetting plastics. There are numerous small channels  113   a  around the circumference of the disk  113 . A series of small protrusions  113   b  is arranged in a circular manner in front of the various channels  113   a.    
         [0022]    Referring back to  FIG. 1   a , the disk  113  is disposed in the ring housing  110 . There is a rim  105  on the inner side of the ring housing  110  for receiving the top part  107  of the disk  113 . The lower flow regulating structure  106  is then received in the mesh socket  108  in the example embodiment. Similarly, there is a rim  109  near one of the ends of the mesh socket  108  to receive the lower flow regulating structure  106 . The disk  113 , the ring housing  110  and the mesh socket  108  are designed to snap fit together in the example embodiment. 
         [0023]    At the other end of the mesh socket  108 , three meshes  112   a ,  112   b  and  112   c  are mounted, with the most dense mesh  112   a  as the topmost layer and the least dense mesh  112   c  as the bottom layer.  FIG. 1   d  shows the three meshes  112   a ,  112   b  and  112   c  with different density in an example embodiment. The meshes  112   a ,  112   b  and  112   c  are made up of thin anti rust wire intercrossed to form a web-like structure. The meshes  11   2   a ,  11   2   b  and  11   2   c  facilitate a more even distribution of the water flow at a water outlet. 
         [0024]    In the example embodiment, the structure  114  comprising of the lower flow regulating structure  106  and the mesh socket  108  is disposed in the enclosure  102  as shown in  FIG. 1   a . The top part of the structure  114  sits on the rim  103  of the enclosure  102  so that it will not fall through the enclosure  102 . 
         [0025]    After the structure  114  is disposed in the enclosure  102 , the upper flow regulating structure  104  is screwed into the enclosure  102 , with its flat surface  11  facing the lower flow regulating structure  106 . A substantially airtight chamber  116  is created between the upper flow regulating structure  104  and lower flow regulating structure  106  in the example embodiment. It is noted that no deformable components such as neoprene O-ring are used in the engagement between the lower flow regulating structure  106 , the mesh socket  108  and the enclosure  102 . The disk  113  and the ring housing  110  are made from substantially solid materials. Due to the non-expandable nature of the solid materials under water pressure, leakage from the chamber  116  will be minimised, thus maintaining the water pressure in the chamber  116 . 
         [0026]    In the example embodiment, the water saving device  100  is designed such that the height of the chamber  116 , which is the distance between the bottom layer of the upper flow regulating structure  104  and the top layer of the lower flow regulating structure  106 , is about one-third of the diameter of a tap outlet  118 . A distance may be varied to regulate a water force (and thus pressure) upon exit from the water saving device  100 . It was found that a larger distance increases the water force and thus pressure. 
         [0027]    The water saving device  100  is screwed to the tap outlet  118  using the remaining threads of the enclosure  102  in an example embodiment. The water saving device  100  can be used on any water tap outlet such as e.g. illustrated in  FIG. 2   a  or shower heads such as e.g. illustrated in  FIG. 2   b  in example embodiments. 
         [0028]    Water saving is carried out by positioning the water saving device  100  along the tap water line  120  at or near the water outlet. The water saving device  100  divides the tap water line  120  along the direction of flow through the means of holes e.g.  104   b  and channels e.g.  113   a  and thereby limits the flow of water. The volume of the water that flows out at tap water line  120   c  is thus significantly reduced. 
         [0029]    However, as mentioned above, in comparison to the existing water saving devices, the water saving device in accordance with the example embodiment of the present invention can maintain increased pressure at the water outlet.  FIG. 3  shows a comparison of measured pressures and flow rates at the water outlet between an existing water saving device and a water saving device in accordance with the example embodiment of the present invention. 
         [0030]    As seen in  FIG. 3 , with the existing water saving device, when the flow rate is reduced to 28.8 litre/min, already the pressure at the outlet is reduced to 1.4 bar for a water tap from a typical line pressure in a household of 2.5 to 3 bar. However, with the water saving device in accordance with the example embodiment of the present invention, even at a flow rate of 13.8 litre/min, the outlet pressure is maintained at 2.4 bar. Similar experiments were conducted at a shower head with the existing water saving device and the water saving device in accordance with the embodiment of the present invention.  FIG. 3  thus illustrates the advantages that can be achieved as a result of the minimisation of leakage in water saving devices according to embodiments of the present invention. 
         [0031]    It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive. 
         [0032]    The configuration of the example embodiments in  FIGS. 1   a - 1   d  is not limited as aforementioned. The materials used for manufacturing the various components of the water saving device  100  are not restricted to those mentioned. The enclosure  102  may be formed by separate parts, e.g. top, middle and bottom enclosures instead of being an one-piece structure. The enclosure  102  and the upper flow regulating structure  104  may be secured together by bolts or welding. The number of holes  104   b  and channels  113   a  is not limited to that shown in  FIGS. 1   b  and  1   c . The holes  104   b  may adopt other shapes. The size of the water saving holes  104   b  and  113   a  is also not limited as shown in this configuration. The number and the density of the meshes  112  may vary in each water saving device  100 .