Abstract:
An energy transfer device comprises a cylinder connected to a reservoir containing water. First and second pistons are connected to each other by a fixed connecting rod and the pistons are mounted in the cylinder. A pocket is associated with one of the first and second pistons and the first and second pistons are positioned in a first position so that the pocket receives a buoyant object. The pistons are moved to a second position so as to release the buoyant object into the reservoir, the movement of the buoyant object rising to the surface of the water contained in the reservoir providing a driving force.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an energy transfer device and particularly to an energy transfer device for use with water.  
       BACKGROUND OF THE INVENTION  
       [0002]     Running water can be harnessed to provide power for machines such as a water mill. A hydroelectric power plant also harnesses the power of running water. The plant typically has a dam on a river to store water in a reservoir. Water released from a reservoir flows through a turbine and the kinetic energy of the flowing water spins the turbine, which in turn activates a generator to produce electricity. The plant thus requires various means to provide and control running water in order to produce electricity.  
       SUMMARY OF THE INVENTION  
       [0003]     It is an object of the invention to use fluid such as water to transfer energy without the need to harness the kinetic energy of running fluid to transfer energy.  
         [0004]     According to one aspect of the present invention there is provided an energy transfer device comprising:  
         [0005]     cylinder means connectable to a reservoir containing fluid;  
         [0006]     first and second pistons connected to each other by connection means so as to be movable with a constant inter-piston distance, the pistons being mounted in the cylinder means; and  
         [0007]     a pocket associated with one of the first and second pistons, wherein the first and second pistons in a first position enable the pocket to receive a buoyant object, and the first and second pistons in a second position enable the pocket to release the buoyant object into the reservoir so that movement of the buoyant object rising to the surface of fluid contained in the reservoir provides a driving force.  
         [0008]     The invention makes use of a buoyant force of a fluid in which an object is placed wherein an upward force is exerted by the fluid upon the object being placed in it. The tendency of the object to float or rise when submerged in the fluid is dependent upon the excess of the relative density of the fluid over that of the object. The fluid is preferably water. The energy transfer device may include the reservoir.  
         [0009]     The energy transfer device may include first drive means for reciprocating the first and second pistons between the first and second pistons. The pistons are preferably reciprocated in a substantially horizontal direction.  
         [0010]     The energy transfer device may include a seal piston movable relative to the connection means between the first and second pistons, and the pocket is formed between one of the first and second pistons and the seal piston. The device may include second drive means for closing up and opening up the pocket.  
         [0011]     The device may include first and second seal pistons movable relative to the connection means between the first and second pistons, and a first pocket is formed between the first piston and first seal piston and a second pocket is formed between the second piston and the second seal piston.  
         [0012]     The energy transfer device may include driven means which is driven by the driving force provided by the rising buoyant object. The driving force may drive an axle of the driven means.  
         [0013]     The energy transfer device may include means for returning a said buoyant object floating at the surface of the reservoir to the pocket when said first and second pistons are in the first position.  
         [0014]     At least one of said first and second pistons may contain a said pocket. A pocket may be associated with each of the first and second pistons.  
         [0015]     According to another aspect of the present invention there is provided a method of transferring energy comprising the steps of:  
         [0016]     providing a reservoir containing fluid, cylinder means connected to the reservoir, first and second pistons connected to each other by connection means so as to be movable with a constant inter-piston distance, the first and second pistons being mounted in the cylinder means, and a pocket associated with one of the first and second pistons;  
         [0017]     positioning the first and second pistons in a first position;  
         [0018]     receiving a buoyant object in the pocket; and  
         [0019]     moving the pistons to a second position so as to release the buoyant object into the reservoir, the movement of the buoyant object rising to the surface of the fluid contained in the reservoir providing a driving force.  
         [0020]     The method may include returning the first and second pistons to the first position and may also include returning a said buoyant object floating at the surface of the reservoir to the pocket when the first and second pistons are in the first position.  
         [0021]     A said buoyant object or another buoyant object may be received in the pocket.  
         [0022]     The pocket formed between one of the first and second pistons and a seal piston movable relative to the connection means between the first and second pistons may be closed up after a said buoyant object contained in the pocket has been released. The pistons may be returned to the first position, and the pocket may be opened up again when the first and second pistons have returned to the first position, or by the time the first and second pistons return to the first position.  
         [0023]     First and second seal pistons may be provided which are movable relative to the connection means between the first and second pistons and a first pocket may be formed between the first piston and the first seal piston, and said buoyant object is received in the first pocket. The first pocket may be closed after said buoyant object contained in the first pocket has been released. A second pocket may be formed between the second piston and the second seal piston, and a second buoyant object is received in the second pocket. The second pocket may be closed after said buoyant object contained in the second pocket has been released into the reservoir. The first and second pistons may be returned to the first position, and the first pocket is opened up again when the first and second pistons have returned to the first position or by the time the first and second pistons return to the first position.  
         [0024]     According to yet another aspect of the present invention there is provided a method of transferring energy comprising the steps of:  
         [0025]     providing a reservoir containing fluid, cylinder means connected to the reservoir, first and second pistons connected to each other by a connection means so as to be movable with a constant inter-piston distance, the pistons being mounted in the cylinder means, and first and second seal pistons movable relative to the connection means;  
         [0026]     positioning the first and second pistons in a first position and forming a first pocket between the first piston and the first seal piston;  
         [0027]     receiving a first buoyant object in the first pocket;  
         [0028]     moving the first and second pistons to a second position so as to release the first buoyant object into the reservoir, the movement of the first buoyant object rising to the surface of the fluid contained in the reservoir providing a driving force;  
         [0029]     closing up the first pocket and forming a second pocket between the second piston and the second seal piston;  
         [0030]     receiving a second buoyant object in the second pocket;  
         [0031]     moving the first and second pistons so as to release the second buoyant object into the reservoir, the movement of the second buoyant object rising to the surface of the fluid contained in the reservoir providing a driving force;  
         [0032]     returning the first and second pistons to the first position; and  
         [0033]     one of the steps of (i) closing up the second pocket and opening up the first pocket again when the first and second pistons have returned to the first position, and (ii) closing up the second pocket and opening up the first pocket again by the time the first and second pistons return to the first position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0034]     Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:  
         [0035]      FIG. 1  is a schematic sectional view of an energy transfer device in accordance with a first embodiment of the invention;  
         [0036]      FIGS. 2A  to  2 E are schematic sectional views of the energy transfer device of  FIG. 1  in various stages of operation;  
         [0037]      FIG. 3  is a modification of  FIG. 1 ;  
         [0038]      FIG. 4  is a schematic sectional view of an energy transfer device in accordance with a second embodiment of the invention;  
         [0039]      FIGS. 5A  to  5 E are schematic sectional views of the energy transfer device of  FIG. 4  in various stages of operation;  
         [0040]      FIG. 6  is a schematic sectional view of an energy transfer device in accordance with a third embodiment of the invention; and  
         [0041]      FIGS. 7A  to  7 E are schematic sectional views of the energy transfer device of  FIG. 6  in various stages of operation. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0042]     With reference to  FIG. 1  of the accompanying drawings, an energy transfer device  1  has a tank or reservoir  2 . A cylinder  3  extends horizontally through the tank  2  and beyond opposite sides of the tank and the bottom of the cylinder  3  is level with the bottom of the tank  2 . Within the tank  2 , the top of the cylinder  3  is open  4 . A first portion  5  of the cylinder  3  extends beyond one side of the tank  2  and contains a first piston  6  which protrudes beyond the cylinder  3 . A second portion  7  of the cylinder  3  extends beyond the opposite side of the tank  2  and contains a second piston  8  which protrudes beyond the cylinder  3 . The first and second pistons  6 , 8  are connected to each other along their longitudinal axes by a fixed rod  9  and a reciprocating motor  10  is connected to the first piston  6  to drive the pistons  6 , 8 . The pistons  6 , 8  fit sufficiently tightly within the cylinder  3  so that a water seal is formed between the outer circumferential surface of the pistons  6 , 8  and the inner circumferential surface of the cylinder  3 .  
         [0043]     The first portion  5  of the cylinder has an opening  11  in the top of the cylinder  3  parallel to the longitudinal axis of the cylinder  3 . The first piston  6  is on one side of the opening  11  and a seal piston  12 , movable along the piston connecting rod  9 , is between the other side of the opening  11  and the tank  2 . The seal piston  12  fits sufficiently tightly around the rod  9  so that a water seal is formed between the seal piston  12  and the rod  9 . The gap beneath the opening  11  and between the first piston  6  and the seal piston  12  forms a pocket  13  for receiving a buoyant barrel  14 . The seal piston  12  is arranged to be driven along the piston connecting rod  9  by seal piston drive means. The seal piston drive means  15  comprises first and second wheels  16 , 17  and a wire  18  extending from one side of the seal piston  12 , through the first piston  6 , around the first wheel  16 , underneath the cylinder  3 , around the second wheel  17  and through the second piston  8  to the opposite side of the seal piston  12 . Seals  19  are formed around the wire  18  passing through the pistons  6 , 8 . When one of the wheels  16 , 17  is driven the seal piston  12  is moved along the rod  9 .  
         [0044]     Inside the tank  2  above the cylinder  3  is a mill  20  comprising a belt  21  stretched continuously around a pair of rollers  22 , 23  arranged one above the other. Each roller  22 , 23  comprises a plurality of wheels  24  fixed to an axle  25 , 26  and each axle  25 , 26  is rotatably supported by supports  27  extending from one side of the tank  2 . A plurality of paddles  28  extends at spaced intervals from and around the belt  21 . The paddles  28  are all inclined at the same acute angle to the belt  21  and in the same direction relative to the belt  21 . The paddles  28  are made of mesh to reduce water resistance.  
         [0045]     Above the top of the tank  2  is a barrel removal means  29 . This comprises another belt  30  stretched continuously around a pair of rollers  31 , 32  arranged one beside the other and a plurality of paddles  33  extends at spaced intervals from and around the belt  30 . To one side of the belt  30  is a funnel  34  the mouth of which is adjacent the top of one side of the tank  2 . The bottom of the funnel  34  is connected to a chute  35 , the bottom of which is connected to the opening  11  in the top of the first portion  5  of the cylinder  3 .  
         [0046]     Referring to  FIGS. 2A  to  2 E, the operation of the energy transfer device  1  will now be described. The mill  20 , funnel  34 , chute  35 , barrel removal means  29 , reciprocating motor  10  and seal piston drive means  15  have been omitted for clarity.  
         [0047]     The tank  2  is filled with water and the seal piston  12  prevents water from the tank  2  leaving via the opening  11  in the top of the first portion  5  of the cylinder  3 . A barrel  14  is dropped through the opening  11  into the pocket  1   3  formed between the first piston  6  and the seal piston  12  ( FIG. 2A ). The motor  10  (see  FIG. 1 ) is started and the pistons  6 , 8  overcome friction resistance.  
         [0048]     The first and second pistons  6 , 8  are pushed along the cylinder  3  and the fixed connecting rod  9  enables the pistons  6 , 8  to have a constant inter-piston distance. When the pocket  13  is aligned with the tank  2  the barrel  14  is released through the open part  4  of the cylinder  3  beneath the tank  2  and the buoyancy of the barrel  14  causes it to rise ( FIG. 2B ).  
         [0049]     The rising barrel  14  engages a paddle  28  of the mill belt  21  (see  FIG. 1 ) causing the belt  21  to turn and driving the axles  25 , 26  of the wheels  24 . The upper axle  25  can be connected to, say, a turbine to generate electricity. The mill  20  thus forms driven means.  
         [0050]     As the first and second pistons  6 , 8  reach the maximum extent of their stroke the first piston  6  engages the seal piston  12  causing the pocket  13  to close up ( FIG. 2C ).  
         [0051]     The first piston  6  with the engaged seal piston  12  and the second piston  8  are pulled back along the cylinder  3  ( FIG. 2D ).  
         [0052]     As the first and second pistons  6 , 8  reach the end of their stroke the first piston  6  disengages from the seal piston  12  causing the pocket  13  to open up. Another barrel  14 ′ is received in the pocket  13  via the opening  11  and the cycle is repeated.  
         [0053]     As more barrels  14  are released into the tank  2  they all engage separate paddles  28  of the mill belt  21 . The more barrels  14  that engage the paddles  28  at any one time increase the speed of rotation of the upper axis  25 .  
         [0054]     When a barrel  14  reaches the surface of the tank  2 , it is pushed by a paddle  33  from the belt  30  of the barrel removal means  29  over the edge of the tank  2  and into the funnel  34 . From there it falls down the chute  35  and back into the cylinder  3  via the opening  11 . The barrel removal means  29 , funnel  34  and chute  35  form means for returning a barrel  14  to the cylinder  3 .  
         [0055]     In a preferred embodiment, the reciprocating motor  10  is a 5 horsepower diesel motor. The pistons  6 , 8  have a stroke of approximately 1 metre and there is a distance of approximately 1 metre between the barrels  14  rising up to the surface of the tank  2 . Each barrel  14  weighs approximately one tonne and there are 95 barrels in circulation in the device  1 .  
         [0056]     A modified energy transfer device  40  is illustrated in  FIG. 3  wherein the device  40  is located underwater and the device  40  consequently no longer requires a tank. The cylinder  41  forms part of a chamber  42  which contains the reciprocating motor  10  and seal piston drive means  15  and seals them from the water in which the device  40  is located. The water in which the device  40  is located may be considered to be a reservoir of water. Also, the mill  43  is supported by supports  44  extending from the chamber  42  beneath.  
         [0057]     An energy transfer device  50  according to a second embodiment is illustrated in  FIG. 4 . The energy transfer device  50  is similar to the energy transfer device  1  of the first embodiment except that there are two seal pistons  12 , 51  movable along the piston connecting rod  52  by the seal piston drive means  53  and that the second end portion  54  of the cylinder  55  also has an opening  56  for receiving buoyant barrels  14 . A second mill  57  is provided in the tank  58  to be driven by the barrels  14  entering the device  50  by the second opening  56  in the cylinder  55  and there is a second barrel removal means  59  and a second funnel  60  and chute  61  for returning the barrels  14  to the second opening  56 .  
         [0058]     Referring to  FIGS. 5A  to  5 E, the operation of the energy transfer device  50  will now be described. The mills  20 , 57 , funnels  34 , 60 , chutes  35 , 61 , barrel removal means  29 , 59 , reciprocating motor  10  and seal piston drive means  53  have been omitted for clarity.  
         [0059]     A barrel  14  is dropped through the first cylinder opening  11  into a first pocket  13  formed between the first piston  6  and the first seal piston  12 . The second seal piston  51  engages the second piston  8  ( FIG. 5A ).  
         [0060]     The first and second pistons  6 , 8  are pushed along the cylinder  55  by the reciprocating motor  10  (see  FIG. 4 ) and when the first pocket  13  is aligned with the tank  58  the barrel  14  is released ( FIG. 5B ) and its buoyancy causes it to rise.  
         [0061]     As the first and second pistons  6 , 8  reach the maximum extent of their stroke the first piston  6  engages the first seal piston  12  causing the first pocket  13  to close up and the second piston  8  disengages from the second seal piston  51  causing a second pocket  62  to open up between them. A buoyant barrel  14 ′ is dropped through the second cylinder opening  56  into the second pocket  62  ( FIG. 5C ).  
         [0062]     The first piston  6  with the engaged first seal piston  12  and the second piston  8  are pulled back along the cylinder  55  and when the second pocket  62  is aligned with the tank  58  the barrel  14 ′ is released ( FIG. 5D ).  
         [0063]     As the first and second pistons  6 , 8  reach the end of their stroke the first piston  6  disengages from the first seal piston  12  causing the first pocket  13  to open up and the second piston  8  re-engages the second seal piston  51  causing the second pocket  62  to close up. Another barrel  14 ″ is received in the first pocket  13  ( FIG. 5E ) and the cycle is repeated.  
         [0064]     An energy transfer device  70  according to a third embodiment is illustrated in  FIG. 6 . Like the energy transfer device  1  of the first embodiment, the energy transfer device  70  has a tank  71  containing a mill  72 , a cylinder  73 , first and second pistons  74 , 75  connected to each other by a fixed connecting rod  76  and a reciprocating motor  77 . The pistons  74 , 75  fit sufficiently tightly within the cylinder  73  so that a water seal is formed between the outer circumferential surface of the pistons  74 , 75  and the inner circumferential surface of the cylinder  73 . Barrel removal means and funnels and chutes for returning barrels to the cylinder have not been shown and the device  70  does not have a seal piston.  
         [0065]     The cylinder  73  is long enough to contain a full stroke of the pistons  74 , 75  and the top of the first and second portions  78 , 79  of the cylinder  73  each has an opening  80 , 81  for receiving a barrel. Aligned with each opening  80 , 81  is a drain hole  82 , 83  in the bottom of the cylinder  73 . Each piston  74 , 75  has a rounded pocket  84 , 85  to receive a barrel via one of the openings  80 , 81  in the cylinder  73  and a drain  86 , 87  from the pocket  84 , 85  to the bottom of the piston  74 , 75 .  
         [0066]     The tank  71  has a funnel-shaped bottom  88  and the neck  89  of the funnel-shaped bottom  88  connects the tank  71  to the cylinder  73  beneath. A water supply  90  is provided to add water to the tank  71  when necessary.  
         [0067]     Referring to  FIGS. 7A  to  7 E, the operation of the energy transfer device  70  will now be described. The mill  72  and reciprocating motor  77  have been omitted for clarity.  
         [0068]     The tank  71  is filled with water and the force of the water acting on each piston  74 , 75  is effectively of equal value and act in opposite directions so that they effectively cancel each other out. This enables the pistons  74 , 75  to be moved with relatively little resistance. The pocket  85  in the second piston  75  is aligned with the neck  89  of the tank  71  and is filled with water from the tank  71 . A buoyant barrel  14  is dropped through the first cylinder opening  80  into the pocket  84  in the first piston  74  ( FIG. 7A ).  
         [0069]     The first and second pistons  74 , 75  are pulled along the cylinder  73  by the reciprocating motor  77  (see  FIG. 6 ) and when the first piston pocket  84  is aligned with the neck  89  of the tank  71  the barrel  14  is released and its buoyancy causes it to rise. When the first piston pocket  84  is aligned with the neck  89  of the tank  71 , the second piston pocket  85  is aligned with the second opening  81  and the second piston drain  87  is aligned with the second drain hole  83  so that water in the second piston pocket  85  is drained via the second piston drain  87  and the second drain hole  83  ( FIG. 7B ).  
         [0070]     A buoyant barrel  14 ′ is then dropped through the second cylinder opening  81  into the second piston pocket  85  ( FIG. 7C ).  
         [0071]     The first and second pistons  74 , 75  are pushed back along the cylinder  73  and when the pistons  74 , 75  have completed the stroke the second piston pocket  85  is aligned with the neck  89  of the tank  71  the barrel  14 ′ is released and water from the tank  71  fills the second piston pocket  85 . The first piston pocket  84  is aligned with the first cylinder opening  80  and the first piston drain  86  is aligned with the first drain hole  82  so that water in the first piston pocket  84  is drained via the first piston drain  86  and the first drain hole  82  ( FIG. 7D ).  
         [0072]     Another barrel  14 ″ is received in the first piston pocket  84  and the cycle is repeated ( FIG. 7E ).  
         [0073]     During a cycle water enters the first and second piston pockets  84 , 85  and is subsequently drained from the pockets  84 , 85  causing water to be lost from the tank  71 . The water supply  90  is used replace this lost water.  
         [0074]     Whilst particular embodiments have been described, it will be understood that various modifications may be made without departing from the scope of the invention. For example, any suitable means may be used to transfer a barrel floating at the top of the tank to the cylinder. Any suitable means may be used to harness the movement of a barrel rising up to the surface in order to provide a driving force.  
         [0075]     The seal piston or pistons may be driven by any suitable means along the connecting rod.  
         [0076]     The cylinder which holds the pistons is not limited to having a circular cross-section. The cylinder forms cylinder means. The cylinder means may comprise, for example, two separate cylinders extending from opposite sides of the tank.  
         [0077]     For the second embodiment, the first and second seal pistons may be replaced by a single seal piston reciprocable to open one pocket formed with either the first or second piston and at the same time close the other pocket formed with the second or first piston.