Abstract:
Provided is a water purifying apparatus. The water purifying apparatus includes a filter unit for filtering water to obtain purified water; a purified water pipe through which the purified water discharged from the filter unit flows; and a cooling unit having the purified water pipe passed therethrough and cooling the purified water pipe to generate cold water. Therefore, the water purifying apparatus may be useful to prevent cold water from being contaminated and re-contaminated, suppress scales from being accumulated therein and obtain water with desired pH density.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of Korean Patent Application No. 2007-40006 filed on Apr. 24, 2007, and Korean Patent Application No. 2007-0077886 filed on Aug. 2, 2007, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a water purifying apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, a water purifying apparatus is an apparatus for filtering foreign objects or heavy metals that are present in water. The water purifying apparatus includes a water purifier, a water ionizer, etc. 
         [0006]    Cold and hot water tanks storing water purified through a filter may be installed in the water purifying apparatus. Water that is previously cooled is stored in the cold water tank, and water that is previously heated is stored in the hot water tank. 
         [0007]    Also, an electrolyzer may be installed in the water purifying apparatus to electrolyze water, thereby providing alkaline water. In this case, a pump is installed in the electrolyzer to force the electrolyzed alkaline water to flow to a water intake unit. 
         [0008]    However, since cold water is stored in the cold water tank for an long time, the cold water may be contaminated as external foreign objects penetrate into the cold water tank. Also, the inner surface of the cold water tank may be incrusted with slime by accumulating unfiltered substances in the cold water to the cold water tank, and therefore water stored in the cold water tank may be re-contaminated. 
         [0009]    In addition, since scales formed in the electrolysis are accumulated in the cold water tank, the cold water may flow out with its being mixed with the scales. 
         [0010]    Additionally, pH density of the cold water may be reduced when the cold water is stored in the cold water tank for a certain period. Furthermore, the reduced pH density of the cold water makes it difficult to obtain water with desired pH density. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention is designed to solve the problems of the prior art, and therefore it is an object of the present invention to provide a water purifying apparatus capable of preventing cold water from being contaminated and re-contaminated, suppressing scales from being accumulated therein and obtaining water with desired pH density. 
         [0012]    According to an aspect of the present invention, there is provided a water purifying apparatus including a filter unit for filtering water to obtain purified water; a purified water pipe through which the purified water discharged from the filter unit flows; and a cooling unit having the purified water pipe passed therethrough and cooling the purified water pipe to generate cold water. 
         [0013]    According to another aspect of the present invention, there is provided a water purifying apparatus including a filter unit for filtering water to obtain purified water; a purified water pipe through which the purified water discharged from the filter unit flows; a cooling unit having the purified water pipe passed therethrough and cooling the purified water pipe to generate cold water; and an electrolyzer for ionizing the purified water discharged from the filter unit into alkaline water and acidic water. 
         [0014]    According to still another aspect of the present invention, there is provided a water purifying apparatus including a filter unit for filtering water to obtain purified water; a purified water pipe through which the purified water discharged from the filter unit flows; a cooling unit having the purified water pipe passed through a lower portion thereof to cool an upper side of the purified water pipe to generate cold water; and an electrolyzer for ionizing the purified water discharged from the filter unit into alkaline water and acidic water. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0016]      FIG. 1  is a configuration view illustrating a water purifying apparatus according to one exemplary embodiment of the present invention, 
           [0017]      FIG. 2  is a configuration view illustrating a water purifying apparatus according to another exemplary embodiment of the present invention, 
           [0018]      FIG. 3  is a configuration view illustrating a cooling unit, which constitutes the water purifying apparatus, according to one exemplary embodiment of the present invention, 
           [0019]      FIG. 4  is a configuration view illustrating a cooling unit, which constitutes the water purifying apparatus, according to another exemplary embodiment of the present invention, 
           [0020]      FIG. 5  is a configuration view illustrating a cooling unit, which constitutes the water purifying apparatus, according to still another exemplary embodiment of the present invention, 
           [0021]      FIG. 6  is a cross-sectional view illustrating the cooling unit as shown in  FIG. 5 , and 
           [0022]      FIG. 7  is a diagram illustrating the simulation results on the computational fluid dynamic analysis in the cooling unit as shown in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
         [0024]      FIG. 1  is a configuration view illustrating a water purifying apparatus according to one exemplary embodiment of the present invention. 
         [0025]    Referring to  FIG. 1 , the water purifying apparatus may include a filter unit  10 , a purified water pipe  20  and a cooling unit  110 . 
         [0026]    The filter unit  10  may include a sediment filter  11 , a pre-carbon filter  12 , a reverse osmosis membrane filter  13  and a post-carbon filter  14 . Also, the filter unit  10  may further include an ultra filtration filter (not shown) and a nano-filtration filter (not shown). 
         [0027]    The sediment filter  11  filters foreign objects and suspended solids that are present in raw water since non-woven fabrics are used for the sediment filter  11 . The pre-carbon filter  12  filters chlorine compounds and odors that are present in raw water since activated carbon is used for the pre-carbon filter  12 . The reverse osmosis membrane filter  13  filters fine particles having a diameter of about 0.001 μm. The post-carbon filter  14  removes pigments and odors since it has relatively more excellent absorption than the activated carbon of the pre-carbon filter. The ultra filtration filter filters bacteria that are present in raw water since string-type hollow membranes are used for the ultra filtration filter. 
         [0028]    The purified water filtered in the filter unit  10  flows along the purified water pipe  20  to the cooling unit  110 . The cooling unit  110  will be described in more detail, as follows. 
         [0029]    The purified water pipe  20  may further include an electrolyzer  101 . In this case, the electrolyzer  101  may be disposed in an inlet or outlet of a purified water of a cooling unit  110 . Also, a check valve  22   a  may be disposed in a purified water pipe section  21  between the cooling unit  110  and the electrolyzer  101 . 
         [0030]    An electrolyzed water pipe  25  may be further provided to directly connect the electrolyzer  101  with the purified water pipe section  21  between the filter unit  10  and the cooling unit  110 . In this case, a three way valve  21   a  may be disposed in an intake end of the electrolyzed water pipe  25 . The three way valve  21   a  selectively supplies purified water discharged from the filter unit  10  to one of the cooling unit  110  and the electrolyzer  101 . The electrolyzed water pipe  25  directly supplies the purified water discharged from the filter unit  10  to the electrolyzer  101  without going through the cooling unit  110 . 
         [0031]    The electrolyzer  101  electrolyzes cold water to ionize the cold water into acidic water and alkaline water. The alkaline water in the electrolyzer  101  is supplied to a water intake unit  60  through a purified water pipe  23 , and the acidic water in the electrolyzer  101  is discharged out through a drain pipe  26 . The water intake unit  60  means that it has the same configuration as a cock through which a user may obtain water. 
         [0032]    The drain pipe  26  may be connected to the purified water pipe section  23  between the electrolyzer  101  and the water intake unit  60 , and a three way valve  23   a  may be disposed in the connected region. 
         [0033]    An operation of the water purifying apparatus according to one exemplary embodiment of the present invention, as configured thus, will be described in more detail. 
         [0034]    Referring to  FIG. 1 , when cold alkaline water is selected, raw water is supplied into the filter unit  10 . The raw water is filtered through the filter unit  10  to become purified water. 
         [0035]    In this case, the purified water discharged from the filter unit  10  flows in the cooling unit  110  under the control of the three way valve  21   a  between the filter unit  10  and the cooling unit  110 . In this case, cooling water in the purified water pipe  20  is cooled quickly while being passed through the cooling unit  110  since the purified water pipe  20  is installed through the cooling unit  110 . 
         [0036]    The purified water cooled in the cooling unit  110  flows in the electrolyzer  101  when the check valve  22   a  is opened. The purified water in the electrolyzer  101  is ionized into acidic water and alkaline water through the electrolysis. The acidic water is discharged out through the drain pipe  26 , and the alkaline water is supplied into the water intake unit  60 . 
         [0037]    Meanwhile, when room-temperature alkaline water is selected, the purified water discharged from the filter unit  10  flows in the electrolyzed water pipe  25  under the control of the three way valve  21   a  between the filter unit  10  and the cooling unit  110 . In this case, the purified water purified in the filter unit  10  may not be supplied to the cooling unit  110 . 
         [0038]    The alkaline water ionized in the cooling unit  110  is directly supplied to the water intake unit  60  to allow a user to obtain alkaline water having exact pH density and a room temperature. Also, the ionized acidic water may be discharged out through the drain pipe  26 . 
         [0039]    For the above-mentioned water purifying apparatus, a user may obtain a cold alkaline water having desired pH density since the alkaline water is supplied to the water intake unit  60  right after the alkaline water is ionized in the electrolyzer  101 . Therefore, it is essentially possible to solve the problem that the pH density of the alkaline water is lowered when the ionized alkaline water is stored for a certain period. 
         [0040]    Also, since the alkaline water ionized is the electrolyzer  101  is immediately discharged into the water intake unit  60 , scales may be prevented from being accumulated inside the electrolyzer  101  although the scales are formed in the electrolysis of purified water in the electrolyzer  101 . 
         [0041]    In addition, flow resistance of water is very low since a cold water tank is not separately installed in the water purifying apparatus and water flows along the purified water pipe  20 . Therefore, an additional pump for forcing water to flow through the purified water pipe  20  does not need to be installed in the water purifying apparatus since the water in the purified water pipe  20  may flow to the water intake unit  60  by means of the hydraulic pressure acting on an inlet of the filter unit  10 . Noises generated in the water purifying apparatus may be significantly reduced since there is no pump installed in the water purifying apparatus. 
         [0042]    The above-mentioned water purifying apparatus is an apparatus that may supply ionized purified water. This water purifying apparatus provides cold ionized water or normal-temperature ionized water according to the preference of users. 
         [0043]    Next, the water purifying apparatus according to another exemplary embodiment of the present invention will be described in more detail. 
         [0044]    The water purifying apparatus according to another exemplary embodiment of the present invention is composed of a block for supplying ionized water and a block for supplying non-ionized purified water. The configuration of supplying ionized water in the another exemplary embodiment is substantially identical to the above-mentioned one exemplary embodiment. Therefore, the block for supplying non-ionized purified water will be described in more detail in the another exemplary embodiment, and the same components have the same reference numerals in the block that is substantially identical to the one exemplary embodiment. 
         [0045]      FIG. 2  is a configuration view illustrating a water purifying apparatus according to another exemplary embodiment of the present invention. 
         [0046]    Referring to  FIG. 2 , the water purifying apparatus according to another exemplary embodiment of the present invention may further include a cold water pipe  28  for connecting the water intake unit  60  to the cooling unit  110 . This cold water pipe  28  directly supplies cold water in the cooling unit  110  to the water intake unit  60  without going through the electrolyzer  101 . 
         [0047]    Also, the water purifying apparatus may further include a bypass pipe  27  for connecting the cold water pipe  28  to the purified water pipe section  21  between the filter unit  10  and the cooling unit  110 . This bypass pipe  27  directly supplies purified water discharged from the filter unit  10  to the water intake unit  60  without going through the cooling unit  110  and the electrolyzer  101 . 
         [0048]    An operation of the water purifying apparatus according to the another exemplary embodiment of the present invention, as configured thus, will be described in detail. 
         [0049]    Referring to  FIG. 2 , the operation of the water purifying apparatus is divided into operations of supplying ionized water or non-ionized water according to the preference of users. Also, the operation of supplying ionized water is divided into operations of supplying cold alkaline water and room-temperature alkaline water, and the operation of supplying non-ionized water is divided into operations of supplying cooling water and room-temperature purified water. The operation of supplying ionized water is substantially identical to that of the one exemplary embodiment, and therefore its description is omitted for clarity. 
         [0050]    When cooling water is selected, the purified water discharged from the filter unit  10  flows in the cooling unit  110  under the control of the three way valve  21   a . In this case, the purified water does not flow in the electrolyzed water pipe  25  and the bypass pipe  27 . 
         [0051]    The purified water flowing in the cooling unit  110  is cooled by the cooling unit  110  to become cooling water. The check valve  21   a  between the cooling unit  110  and the electrolyzer  101  closes a channel, and the three way valve  28   a  of the cold water pipe  28  opens a channel of the cold water pipe  28 . 
         [0052]    Since the purified water pipe  20  goes through the cooling unit  110 , the cooling water in the purified water pipe  20  is quickly cooled while being passed through the cooling unit  110 . The cooling water in the cooling unit  110  flows along the cold water pipe  28 , and flows in the water intake unit  60 . Therefore, a user may obtain the cooling water. 
         [0053]    Meanwhile, the three way valve  21   a  between the filter unit  10  and the cooling unit  110  is closed when room-temperature purified water is selected. In this case, the purified water in the filter unit  10  does not flow in the cooling unit  110  and the electrolyzed water pipe  25 . 
         [0054]    The room-temperature purified water in the filter unit  10  flows along the bypass pipe  27 . In this case, the room-temperature purified water in the bypass pipe  27  flows in the water intake unit  60  under the control of the three way valve  28   a  disposed in the outlet of the bypass pipe  27 . Therefore, a user may obtain the room-temperature purified water. 
         [0055]    Also, a cold water tank is not separately installed in the water purifying apparatus, and therefore it is possible to significantly reduce flow resistance of water since water flows along the purified water pipe  20  even when the ionized water or non-ionized purified water flows in the water purifying apparatus. Therefore, it is possible to significantly reduce noises generated in the water purifying apparatus since an additional pump for forcing water to flow through the purified water pipe  20  does not need to be installed in the water purifying apparatus. 
         [0056]    The cooling unit  110  for quickly cooling purified water is commonly used in the above-mentioned water purifying apparatus according to the one and another exemplary embodiment of the present invention. Hereinafter, the cooling unit  11  that may be used for the one and another exemplary embodiment will be described in more detail. 
         [0057]      FIG. 3  is a configuration view illustrating a cooling unit, which constitutes the water purifying apparatus, according to one exemplary embodiment of the present invention. 
         [0058]    Referring to  FIG. 3 , the cooling unit  110  may include an evaporator  111 , a heat storage unit  112 , an antifreeze circulating unit  115  and a heat exchanging unit  118 . 
         [0059]    The evaporator  111  constitutes some of a refrigerant system including a compressor (not shown), a condenser (not shown) and an expansion member (not shown). When the cooling system is put into operation, a refrigerant compressed in the compressor flows in the condenser and the expansion member and is expanded to supply a low-pressure refrigerant to the evaporator  111 . 
         [0060]    A circulation pipe  116  and a purified water pipe  31  are disposed through the heat exchanging unit  118 . A heat transfer fluid may be carried in the heat exchanging unit  118 . 
         [0061]    In this case, the purified water pipe section  31  going through the heat exchanging unit  118  may be held, in a linear form or in a spirally coiled form, inside the heat exchanging unit  118 . When the purified water pipe has a spirally coiled shape, this results in the increase in the time that the purified water pipe exchanges heat with the heat exchanging unit  118 . 
         [0062]    The cooling unit  110  may further include a heat storage unit  112  and an antifreeze circulating unit  115 . The heat storage unit  112  and the antifreeze circulating unit  115  transfers cold air to the heat exchanging unit  118 . 
         [0063]    The heat storage unit  112  may include a receptor member  113  having the evaporator  111  passed therethrough, and a heat exchange medium  114  held inside the receptor member  113 . A heat transfer fluid or ice may be used as the heat exchange medium  114 . 
         [0064]    The antifreeze circulating unit  115  may include a circulation pipe  116  through which an antifreeze flows, and a circulating pump  117  for forcing the antifreeze in the circulation pipe  116  to flow. Here, a calcium chloride solution, a magnesium chloride solution, an ethylene glycol solution or an ethyl alcohol solution may be used as the antifreeze. 
         [0065]    An operation of the cooling unit  110  according to the one exemplary embodiment, as configured thus, will be described in detail. 
         [0066]    When the refrigerant system is put into operation, a low-temperature refrigerant flows in the evaporator  111 . Cold air in the evaporator  111  cools water in the heat storage unit  112  to form ice in the heat storage unit  112 . In this case, the heat storage unit  112  functions in fact as an ice storage unit  112  since it thermally stores cool air by means of the ice. 
         [0067]    Also, when the pump of the antifreeze circulating unit  115  is put into operation, an antifreeze circulates along the circulation pipe  116 . The antifreeze in the circulation pipe  116  cools the heat exchanging unit  118  by transferring cool air of the heat storage unit  112  to the heat exchanging unit  118 . In this case, purified water in the purified water pipe  31  is quickly cooled whiled being passed through the heat exchanging unit  118  since the purified water pipe  31  is installed through the heat exchanging unit  118 . 
         [0068]    As described above, the water purifying apparatus has a configuration of quickly cooling the purified water flowing along the purified water pipes, followed by immediately obtaining the cooled purified water through the water intake unit  60 . This water purifying apparatus has an advantage that, since a cold water tank is not separately installed in the water purifying apparatus, it is essentially possible to prevent external contaminants from flowing inside the cold water tank so as to contaminate cold water. Also, it is possible to reduce the volume of the water purifying apparatus since the cold water tank is not separately installed in the water purifying apparatus. 
         [0069]      FIG. 4  is a configuration view illustrating a cooling unit, which constitutes the water purifying apparatus, according to another exemplary embodiment of the present invention. 
         [0070]    Referring to  FIG. 4 , the cooling unit  120  may include an evaporator  121  and a heat exchanging unit  123 . 
         [0071]    A heat transfer fluid  124  is accommodated inside the heat exchanging unit  123 . In this case, various heat transfer fluids such as water and antifreeze may be used as the heat transfer fluid  124 . 
         [0072]    The purified water pipe  33  in a coiled form is held in the heat exchanging unit  123 , and the evaporator  121  may have a coiled form so that it can surround a coiled form of the purified water pipe section  33 . In this case, the length of a refrigerant pipe held in the heat exchanging unit  123  may be relatively extended since the evaporator  121  is formed so that it can surround a coiled form of the purified water pipe section  33 . In addition, a cooling capacity of the heat exchanging unit  123  may be increased. 
         [0073]    Here, it is preferred to prevent the purified water from being frozen in the purified water pipe section  33  by arranging the evaporator  121  to be spaced apart from a coiled section  33  of the purified water pipe. 
         [0074]    Also, the evaporator  121  may include a heat transfer member such as an aluminum sheet with excellent conductivity, and a refrigerant pipe installed in a zigzag type inside the heat transfer member. In this case, the heat transfer member may be disposed so that it can surround the purified water pipe  33 . This configuration is not shown herein. 
         [0075]    The heat exchanging unit  123  may further include a stirrer  126  to force the heat transfer fluid  124  to flow. The stirrer  126  may include a motor  127  and a fan  128 . The fan  128  of the stirrer  126  may rotate in a direction in which purified water flows along the purified water pipe  20 , or in its reverse direction. 
         [0076]    An operation of the cooling unit according to another exemplary embodiment, as configured thus, will be described in detail. 
         [0077]    When the refrigerant system is put into operation, a refrigerant in the evaporator  121  flows along the coiled section of the purified water pipe. Also, when the fan  128  of the stirrer  126  rotates in a direction where the refrigerant in the evaporator  121  flows, and in its reverse direction, the heat transfer fluid  124  in the heat exchanging unit  123  forms a water current against a direction where the refrigerant flows round. Therefore, it is possible to improve heat exchange efficiency between the heat transfer fluid  124  and the refrigerant. 
         [0078]    The purified water pipe  33  has a coiled region which goes through the heat exchanging unit  123 , and there fore the purified water may be sufficiently cooled while being passed through the heat exchanging unit  123 . 
         [0079]    As described above, the water purifying apparatus has a configuration of quickly cooling the purified water flowing along the purified water pipes  33 , followed by immediately obtaining the cooled purified water through the water intake unit  60 . This water purifying apparatus has an advantage that, since a cold water tank is not separately installed in the water purifying apparatus, it is essentially possible to prevent external contaminants from flowing inside the cold water tank so as to contaminate cold water. Also, it is possible to reduce the volume of the water purifying apparatus since the cold water tank is not separately installed in the water purifying apparatus. 
         [0080]      FIG. 5  is a configuration view illustrating a cooling unit, which constitutes the water purifying apparatus, according to still another exemplary embodiment of the present invention,  FIG. 6  is a cross-sectional view illustrating the cooling unit, and  FIG. 7  is a diagram illustrating the simulation results on the computational fluid dynamic analysis in the cooling unit. 
         [0081]    Referring to  FIG. 5 , the cooling unit  130  may include an evaporator  131  disposed on the purified water pipe  35 , and a heat exchanging unit  133  carrying a heat transfer fluid for exchanging heat between the evaporator  131  and the purified water pipe  35 . 
         [0082]    In this case, when the heat transfer fluid is water, the evaporator  131  is disposed so that it can be passed through an upper portion of the purified water pipe  35 , and therefore the purified water pipe  35  may be disposed so that it cannot interfere with ice formed in cooling the water. 
         [0083]    The purified water pipe  35  goes through the heat exchanging unit  133 , and the evaporator  131  may be disposed on the purified water pipe  35  so that it can be spaced apart from the purified water pipe  35 . 
         [0084]    The purified water pipe  35  in a coiled form may be disposed below the heat exchanging unit  133 . This purified water pipe may be wound so that its coiled region  35  can be arranged in parallel. 
         [0085]    The refrigerant pipe is formed in a coiled form, and the evaporator  131  may be then disposed on the purified water pipe  35 . A heat exchange pin may be formed in the evaporator  131 . 
         [0086]    Also, the evaporator  131  may include a heat transfer member such as an aluminum sheet with excellent conductivity, and a refrigerant pipe installed in a zigzag type inside the heat transfer member. However, this configuration is not shown herein. 
         [0087]    A heat transfer fluid  134  is accommodated inside the heat exchanging unit  136 . In this case, various heat transfer fluids such as water and antifreeze may be used as the heat transfer fluid  134 . 
         [0088]    The cooling unit  130  may further include a stirrer  136  to force the heat transfer fluid  134  to flow. The stirrer  136  may further include a motor  137  and a fan  138 . The fan  138  of the stirrer  136  may rotate in the opposite direction of the purified water flowing along the purified water pipe  35  to form a water current of the heat transfer fluid  134  against a direction where the purified water flows round. Therefore, it is possible to improve heat exchange efficiency between the heat transfer fluid  134  and the purified water pipe  35 . 
         [0089]    An operation of the cooling unit according to still another exemplary embodiment of the present invention, as configured thus, will be described in detail. 
         [0090]    Referring to  FIG. 6 , the heat transfer fluid  134  of the heat exchanging unit  133  is cooled in the vicinity of the evaporator  131  for the first time since a coiled section of the evaporator  131  is disposed on the heat exchanging unit  133 . 
         [0091]    In this case, when water is used as the heat transfer fluid  134 , the water is frozen from the top due to the difference in its density gradient because the water has the highest density at 4° C. In this case, the evaporator is disposed so that it can be passed through an upper portion of the purified water pipe, and therefore the purified water pipe may be disposed so that it cannot interfere with ice formed in cooling the water. 
         [0092]    When the temperature of water is suddenly dropped by the evaporator  131 , the water in the heat exchanging unit  133  is divided into up and down regions, i.e., an ice region and a heat exchange region. Therefore, it is able to prevent the purified water in the purified water pipe  35  from being frozen although the temperature of the water is dropped suddenly. 
         [0093]    Referring to  FIG. 7 , a temperature distribution of the heat exchanging unit  133  is simulated using the computational fluid dynamic analysis. As a result, it is revealed that ice grows only at an upper portion of the heat exchanging unit  133  but hardly grows toward a lower portion of the heat exchanging unit  133  although the temperature of the water is dropped suddenly. Therefore, it is possible to prevent the purified water in the purified water pipe  35  from being frozen although the water is used as the heat transfer fluid  134  in the heat exchanging unit  133 . 
         [0094]    Since ice does not grow into the bottom of the heat exchanging unit  133  not to interfere with the purified water pipe  35 , it is able to prevent the purified water in the purified water pipe  35  from being frozen 
         [0095]    While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.