Abstract:
An air pump for a fish-tank comprises a compartmental air chamber assembly formed by a base plate and a casing in the body. Hence, an indirect prolonged air path is formed in the air chamber assembly, resulting in a great reduction of noise generated while operating.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to air pump and more particularly to an air pump for a fish-tank with noise silence arrangement.  
         BACKGROUND OF THE INVENTION  
         [0002]    A conventional air pump  10  for fish-tank is shown in FIG. 1 comprising a body  11 , a cap  12 , a front vibration mechanism  13  secured to cap  12  having a magnet  131  at one side, a pair of check mechanisms  14  with body  11  sandwiched therebetween, and a rear plate  15 . Each of the components is detailed below. Body  11  comprises an inlet air chamber  111  with cap  12  clung onto, an outlet air chamber  112  divided from inlet air chamber  111  by a central wall, an inlet  113 , an outlet  114  both on the central wall, a first slot  115  in inlet air chamber  111 , a second slot  115  in outlet air chamber  112  wherein each air pump  14  is inserted in the corresponding slot  115 , a discharge opening  116  on the bottom of inlet air chamber  111  in communication with the external of body  11 , and a discharge pipe  17  on the side opposite to the discharge opening  116 . Check mechanism  14  comprises a diaphragm  142  and a block member  141  for pressing diaphragm  142  onto slot  115  for releasably covering inlet  113  (or outlet  114 ). The rear side of body  11  is sealed by rear plate  15 .  
           [0003]    Operation:  
           [0004]    When air pump  10  is activated, an activated external electromagnetic device (not shown) will reciprocally attract and repulse the magnet  131 , thus causing the magnet  131  to vibrate toward cap  12  about the other side of vibration mechanism  13 . Hence, cap  12  is reciprocally pushed and pulled. When cap  12  is pulled up, external air will suck into inlet air chamber  111  through discharge opening  116 . Then air is guided to outlet  114  through inlet  113 . To the contrary when cap  12  is pushed down, internal air will be compressed into outlet air chamber  112  through outlet  114 . Then the compressed air is discharged out of discharge pipe  117 . As a result, fresh compressed air may be pumped into water in fish-tank by the reciprocation of vibration mechanism  13 . However, the previous design suffered from a disadvantages, i.e., it is very noisy. This is because an air path within the air pump  10  (i.e., from inlet  113  to inlet air chamber  111 ) is short, resulting in a quick discharge of air. Thus, it is desirable to provide an air pump with prolonged air path for effectively attenuating noise when air pump is operating, thereby overcoming the above drawbacks of prior art.  
         SUMMARY OF THE INVENTION  
         [0005]    It is an object of the present invention to provide an air pump for a fish-tank comprising a base plate; a body comprising a frame, an inlet air chamber, an outlet air chamber divided by the frame, a first and a second inlets at the inlet air chamber, a first and a second outlets at the outlet air chamber, a slot on each of the first inlet and the first outlet, a discharge pipe, and a bottom casing comprising an air charge opening on the top in communication with outside, a compartmental air chamber assembly, an air charge tube extended down from the air charge opening to the compartmental air chamber assembly, the bottom end of the air charge tube urged against the inner wall of the base plate, and one or more third outlets on the edge of the bottom end of the air charge tube; a cap clung onto the frame; a vibration mechanism secured to the outer surface of the cap, the vibration mechanism comprising a magnet at one side; a pair of check mechanisms with the body sandwiched therebetween, each of the check mechanisms clung to the corresponding slot and comprising a block member and a diaphragm for regulating air passing through the first inlet and the first outlet; a pad clung to the rear side of the body; and a rear plate clung to the rear side of the pad; wherein air is guided into the air chamber assembly prior to leaving the discharge pipe. By utilizing such indirect air path in the air chamber assembly, noise generated while air pump is operating is greatly reduced.  
           [0006]    It is another object of the present invention to provide an air pump for a fish-tank comprising a pair of base plates; a body comprising a frame, an inlet air chamber, an outlet air chamber divided by the frame, a first and a second inlets at the inlet air chamber, a first and a second outlets at the outlet air chamber, a slot on each of the first inlet and the first outlet, a discharge pipe, and a bottom casing comprising an air charge opening on the top in communication with outside, a pair of compartmental air chamber assemblies, an air charge tube extended down from the air charge opening to one of the compartmental air chamber assemblies, the bottom end of the air charge tube urged against the inner wall of one of the base plates, and one or more third outlets on the edge of the bottom end of the air charge tube; a pair of caps each clung onto the frame; a pair of vibration mechanisms each secured to the outer surface of each cap, each vibration mechanism comprising a magnet at one side; a pair of check mechanisms with the body sandwiched therebetween, each of the check mechanisms clung to the corresponding slot and comprising a block member and a diaphragm for regulating air passing through the first inlet and the first outlet; a pad clung to the rear side of the body; and a rear plate clung to the rear side of the pad; wherein air is guided into the air chamber assemblies prior to leaving the discharge pipe. By utilizing such indirect air path in the air chamber assemblies, noise generated while air pump is operating is further greatly reduced.  
           [0007]    The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is an exploded view of a conventional air pump;  
         [0009]    [0009]FIG. 2 is an exploded view of a first preferred embodiment of air pump with noise silence arrangement according to the invention;  
         [0010]    [0010]FIG. 3 is a perspective view of casing of FIG. 2; FIG. 4 is a sectional view illustrating an air path in the air pump of FIG. 2;  
         [0011]    [0011]FIG. 5 is another sectional view further illustrating the air path of FIG. 4;  
         [0012]    [0012]FIG. 6 is a perspective view of the assembled FIG. 2 air pump;  
         [0013]    [0013]FIG. 7 is top view of a second preferred embodiment of air pump with noise silence arrangement according to the invention;  
         [0014]    [0014]FIG. 8 is a sectional view illustrating an air path in the air pump of FIG. 7; and  
         [0015]    [0015]FIG. 9 is another sectional view further illustrating the air path of FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    Referring to FIGS.  2  to  6 , there is shown a first preferred embodiment of air pump  2  constructed in accordance with the invention comprising a body  21 , a base plate  22 , a cap  24 , a vibration mechanism  23 , a pair of check mechanisms  25  and  26  with body  21  sandwiched therebetween, a pad  27 , and a rear plate  28 . Each of the components is detailed below. An inlet air chamber  211  and an outlet air chamber  212  are divided by a circular frame  210  on body  21 . Pad  27  and rear plate  28  are clung to the rear side of body  21 . An inlet  2111  and an outlet  2121  are provided at inlet air chamber  211  and outlet air chamber  212  respectively. Cap  24  is clung onto frame  210 . Vibration mechanism  23  is threadedly secured to the center of the outer surface of cap  24 . Vibration mechanism  23  comprises a magnet  231  at one side. A slot (not shown) is formed on each of inlet  2111  and outlet  2121 . Check mechanisms  25  and  26  are clung to the slots respectively. Check mechanism  25  (or  26 ) comprises a block member  251  (or  261 ) and a diaphragm  252  (or  262 ) for regulating air passing through inlet  2111  and outlet  2121 . An inlet  213  is formed on inlet air chamber  211 . An outlet  214  is formed on outlet air chamber  212 . A noise silence arrangement is provided in a casing  215  at the bottom of body  21 . In detail, casing  215  comprises an air charge opening  2150  on the top in communication with outside, an air charge tube  2151  extended down from air charge opening  2150  to a first air chamber A 1 , bottom end  2152  of air charge tube  2151  urged against the inner wall of compartment  221  on base plate  22 , and one or more outlets  2153  formed on the edge of bottom end  2152  of air charge tube  2151  for guiding air into first air chamber A 1  in order to avoid air from directly guiding into first air chamber A 1  otherwise causing strong noise. Compartments  2156 ,  2157 ,  2158 , and  2159  are formed in casing  215  by dividers C 1 , C 2 , and C 3 . Each of compartments  2156 ,  2157 ,  2158 , and  2159  is matingly engaged with one of compartments  221 ,  223 ,  225 , and  226  on base plate  22  to form a first air chamber A 1 , a second air chamber A 2 , a third air chamber A 3 , and a fourth air chamber A 4  respectively. An opening  2154  is provided between first air chamber A 1  and second air chamber A 2 . An inlet  213  is provided on a side of compartment  2157  in second air chamber A 2  in communication with inlet air chamber  211 . An outlet  214  is provided on a side of compartment  2158  in second air chamber A 2  in communication with outlet air chamber  212 . An opening  2155  is provided between third air chamber A 3  and fourth air chamber A 4 . A passageway  216  is provided on a side of compartment  2159  in fourth air chamber A 4  in communication with discharge pipe  117 . Base plate  22  is clung to casing  215  to form a unit. Compartments  221 ,  223 ,  225 , and  226  are formed in base plate  22  by dividers B 1 , B 2 , and B 3 . A riser  222  having a cross-sectional area slightly smaller than the diameter of inlet  213  is provided on a side of compartment  223  in second air chamber A 2  corresponding to inlet  213 . A recess  2221  is provided on riser  222 . Similarly, a riser  224  having a cross-sectional area slightly smaller than the diameter of outlet  214  is provided on a side of compartment  225  in third air chamber A 3  corresponding to outlet  214 . A recess  2241  is provided on riser  224 . Operation: Referring to FIGS. 4 and 5 specifically, when air pump  20  is activated, an activated external electromagnetic device (not shown) will reciprocally attract and repulse the magnet  231 , thus causing the magnet  231  to vibrate toward cap  24  about the other side of vibration mechanism  23 . Hence, cap  24  is reciprocally pushed and pulled. When cap  24  is pulled up, external air will suck into air charge tube  2151  of casing  215  through air charge opening  2150 . Then air is guided to first air chamber A 1  through outlet  2153  on the periphery of bottom end  2152  of air charge tube  2151 . As a result, noise mainly caused by air directly guiding into air chambers is attenuated by such indirect air path. Air is then guided from first air chamber A 1  to second air chamber A 2  through opening  2154 . Air is partly blocked by riser  222  in the air chamber of inlet  213 , thus preventing air from directly guiding into inlet  213 . Instead, air is guided indirectly to inlet air chamber  211  through the gap between inlet  213  and riser  222  and recess  2221  of riser  222 . This may further reduce noise. Air in inlet air chamber  211  is then guided to outlet  214  through check mechanisms  25  and  26 , inlet  2111 , outlet  2121 , and outlet air chamber  212 . Since the opening of outlet  214  is partly blocked by riser  224 , thus guiding air indirectly to third air chamber A 3  through the gap between outlet  214  and riser  224 . This may furthermore reduce noise. Next air is guided from third air chamber A 3  to fourth air chamber A 4  through opening  2155 . Finally, air is discharged from discharge pipe  217  through passageway  216 . By utilizing such indirect air path, noise generated while air pump  20  is operating is greatly reduced.  
         [0017]    Referring to FIGS. 7, 8, and  9 , a second preferred embodiment of air pump  4  according to the invention is shown. The difference between first and second embodiments is that the later is double configured partly. For example, a first air path is formed in casing  42  in one side of body  41  and a second air path is formed in base plate  43  in the other side of body  41 . Further, a pair of vibration mechanisms  44  and  44 ′ and a pair of caps  45  and  45 ′ are provided in cooperation with base plate  43  and case  42 . The in and out arrangement of air is substantially the same as the first embodiment. For example, there are provided air charge openings  416  and  416  , first air chambers E 1  and E 1 ′, second air chambers E 2  and E 2 ′ , third air chambers E 3  and E 3 ′, fourth air chambers E 4  and E 4 ′, and discharge pipes  417  and  417 ′. Note that each of inlets  413  and  413 ′ of inlet air chambers  411  and  411 ′ has a round opening. Similarly, each of outlets  414  and  414 ′ of outlet air chambers  412  and  412 ′ has a round opening. Posts  4221 ,  4221 ′,  4231 , and  4231 ′ are provided on second and third air chambers E 2 , E 2 ′, E 3 , and E 3 ′ of base plate  43  respectively. Each post is corresponding to one of the round openings. Hence, posts  4221 ,  4221 ′,  4231 , and  4231 ′ are capable of inserting into the round openings. Note that the function of post is the same as riser in the first embodiment for partly blocking the incoming air. The cross-sectional area of each of posts  4221 ,  4221 ′,  4231 , and  4231 ′ is slightly smaller than the diameter of each of inlets  413  and  413 ′ and outlets  414  and  414 , thus leaving gaps for allowing air to pass through. As a result, noise generated while air pump  40  is operating is also greatly reduced by such indirect air path.  
         [0018]    While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.