Abstract:
The present invention relates to a sound elimination structure for an air pump, especially an air pump which is used in an aquarium. The sound elimination structure includes a sound elimination device including an air chamber box, and an air chamber cover secured with each other and defining a plurality of chambers therein. The air chamber cover and the air chamber box are provided with air guide tubes, recesses, air holes co-operating with catch plates so as to increase the path of the air flow, thereby reducing the velocity of the air flow so as to eliminate the noise.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sound elimination structure for an air pump which is especially used in an aquarium. 
     2. Description of the Related Art 
     A conventional air pump  10  for an aquarium in accordance with the prior art shown in FIG. 1 comprises a body  11  including an air inlet chamber  111  having an air inlet hole  113  forming a receiving recess  115 , an air outlet chamber  112  having an air outlet hole  114  forming a receiving recess  115 , an air suction hole  116  defined in the body  11 , an air drain pipe  117  mounted on the body  11 , a bottom cap  15  mounted on the body  11 , a compression cup  12  mounted on the body  11 , a vibration crank  13  mounted on the compression cup  12 , a magnet  131  mounted on one end of the vibration crank  13 , two anti-reverse structures  14  each received in the receiving recess  115  and each including an anti-reverse diaphragm  142  releasably encompassing the air inlet hole  113  and the air outlet hole  114 , and a press block  141  pressing the anti-reverse diaphragm  142 . 
     In operation, when the air pump  10  is energized, the magnet  131  is attracted or repelled by an electromagnetic device (not shown) to force the vibration crank  13  to vibrate so that the compression cup  12  can be pressed to move toward the body  11 , and can be expanded to move opposite to the body  11 . When the compression cup  12  is expanded to move opposite to the body  11 , the environmental air is drawn into the air inlet chamber  111  through the air suction hole  116  and the air inlet hole  113 . The anti-reverse diaphragm  142  is used to prevent the air from flowing back. When the compression cup  12  is pressed to move toward the body  11 , the air is forced to flow through the air outlet hole  114  into the air outlet chamber  112 , and is finally carried to the ambient environment through the air drain pipe  117 . However, the travel path of the flowing air is very short, and the flowing air has a great velocity so that the flowing air easily create noise in the air pump  10 . 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, there is provided a sound elimination structure for an air pump comprising: a body, a compression cup, a vibration crank, and two anti-reverse structures, wherein, the body is separated into an air inlet chamber and an air outlet chamber and has a first side provided with a washer and a cover plate and a second side provided with a flange, the air inlet chamber is provided with an air input hole and an air inlet hole, the air outlet chamber is provided with an air output hole and an air outlet hole, the vibration crank has a first side secured on the compression cup which is mounted on the lug and a second side provided with a magnet co-operating with an external electromagnetic device, each of the air input hole and the air output hole defines a recess for receiving an anti-reverse structure, the improvement comprising: 
     the body provided with a sound elimination device which comprises an air chamber box, and an air chamber cover, wherein, 
     the air chamber cover is provided on one side of the body, and is separated by a plurality of baffles into a first chamber, a second chamber, a third chamber, and a fourth chamber, an air inlet guide hole defined in the first chamber and connecting to an external air extraction hole, an air inlet chamber air inlet hole defined in the second chamber and connecting to the air inlet chamber of the body, an air outlet chamber air outlet hole defined in the third chamber and connecting to the air outlet chamber of the body, an air conveying hole defined in the fourth chamber and connecting to an air outlet tube of the body, a guide hole defined between the first chamber and the second chamber; and 
     the air chamber box is separated by a plurality of baffles into an air inlet cabin, a first circuitous chamber, a second circuitous chamber, and an air guide chamber, each of the first circuitous chamber and second circuitous chamber provided with a catch plate which is fitted in the air inlet chamber air inlet hole and the air outlet chamber air outlet hole, and a guide hole defined between the second circuitous chamber and the air guide chamber. 
     In accordance with another aspect of the present invention, wherein, 
     the air chamber cover is separated by a plurality of baffles into a first chamber, a second chamber, a third chamber, and a fourth chamber, the third chamber connecting to the fourth chamber, an air guide tube mounted in the first chamber and connecting to an external air extraction hole, an air inlet chamber air inlet hole defined in the second chamber and connecting to the air inlet chamber of the body, an air outlet chamber air outlet hole defined in the third chamber and connecting to the air outlet chamber of the body, an air conveying hole defined in the fourth chamber and connecting to an air outlet tube of the body, a guide hole defined between the first chamber and the second chamber; and 
     the air chamber box is separated by a plurality of baffles into an air inlet cabin, a first circuitous chamber, a second circuitous chamber, and an air guide chamber, a first lug mounted in the air inlet cabin and loosely fitted in the air guide tube of the first chamber of the air chamber cover, and a second lug mounted in the first circuitous chamber and loosely fitted in the air inlet chamber air inlet hole of the second chamber of the air chamber cover. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded view of a conventional air pump in accordance with the prior art; 
     FIG. 2 is an exploded view of a sound elimination structure for an air pump in accordance with the present invention; 
     FIG. 3 is a perspective assembly view of the sound elimination structure as shown in FIG. 2; 
     FIG. 4 is a front plan cross-sectional view of the sound elimination structure as shown in FIG. 3; 
     FIG. 5 is a bottom plan cross-sectional view of the sound elimination structure as shown in FIG. 3; 
     FIG. 6 is an exploded view of a sound elimination structure for an air pump in accordance with another embodiment of the present invention; 
     FIG. 7 is a perspective assembly view of the sound elimination structure as shown in FIG. 6; 
     FIG. 8 is a front plan cross-sectional view of the sound elimination structure as shown in FIG. 7; 
     FIG. 9 is a bottom plan cross-sectional view of the sound elimination structure as shown in FIG. 7; 
     FIG. 10 is a top plan view of a sound elimination structure for an air pump in accordance with a further embodiment of the present invention; 
     FIG. 11 is a front plan cross-sectional view of the sound elimination structure as shown in FIG. 10; and 
     FIG. 12 is a bottom plan view of the sound elimination structure as shown in FIG. 10 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to FIGS. 2-5, a sound elimination structure in accordance with the present invention is used for an air pump  20  which comprises a body  21 , a compression cup  22 , a vibration crank  23 , and two anti-reverse structures  24 . 
     The body  21  is separated into an air inlet chamber  211  and an air outlet chamber  212  and has a first side provided with a washer  215  and a cover plate  216  and a second side provided with a flange  25 . The air inlet chamber  211  is provided with an air input hole  2111  and an air inlet hole  213 . The air outlet chamber  212  is provided with an air output hole  2121  and an air outlet hole  214 . The vibration crank  23  has a first side secured on the compression cup  22  which is mounted on the lug  25  and a second side provided with a magnet  231  co-operating with an external electromagnetic device (not shown). Each of the air input hole  2111  and the air output hole  2121  defines a recess (not shown) for receiving an anti-reverse structure  24 . 
     The body  21  is provided with a sound elimination device  30  which comprises an air chamber box  32 , and an air chamber cover  31  secured with each other. 
     The air chamber cover  31  is provided on one side of the body  21 , and is separated by a plurality of baffles  315  into a first chamber  311 , a second chamber  312 , a third chamber  313 , and a fourth chamber  314 . An air inlet guide hole  3111  is defined in the first chamber  311  and connects to an external air extraction hole  316 . An air inlet chamber air inlet hole  3121  is defined in the second chamber  312  and connects to the air inlet chamber  211  of the body  21 . An air outlet chamber air outlet hole  3131  is defined in the third chamber  313  and connects to the air outlet chamber  212  of the body  21 . An air conveying hole  3141  is defined in the fourth chamber  314  and connects to an air outlet tube  26  of the body  21 . A guide hole  317  is defined between the first chamber  311  and the second chamber  312 . 
     The air chamber box  32  has an inner wall provided with a fitting groove  326  for fitting of the air chamber cover  31  so as to form a tight fitting state therebetween, thereby preventing the air from leaking. The air chamber box  32  can be separated by a plurality of baffles  325  into an air inlet cabin  321 , a first circuitous chamber  322 , a second circuitous chamber  323 , and an air guide chamber  324  which are not in communication with each other and are respectively mated with each of the chambers of the air chamber cover  31 . The air inlet cabin  321  defines a recess  3211  fitted with the air inlet guide hole  3111  of the air chamber cover  31 . Each of the first circuitous chamber  322  and the second circuitous chamber  323  is provided with a catch plate  3221  and  3231  which is respectively fitted in the air inlet chamber air inlet hole  3121  and the air outlet chamber air outlet hole  3131 . Each of the catch plates  3221  and  3231  has a dimension smaller than that of each of the air inlet chamber air inlet hole  3121  and the air outlet chamber air outlet hole  3131 . A guide hole  327  is defined between the second circuitous chamber  323  and the air guide chamber  324 . 
     In operation, when the air pump  20  is energized, the magnet  231  is attracted or repelled by means of an electromagnetic device (not shown), thereby forcing the vibrating crank  23  to vibrate so that the compressing cup  22  can be pressed to move toward the body  21 , and can be expanded to move opposite to the body  21 . 
     When the compression cup  22  is pulled outward, the environmental air is drawn through the air extraction hole  316  into the air inlet guide hole  3111  of the air chamber cover  21  of the sound elimination device  30 . 
     When the air is introduced into the first chamber  311  (mating with the air inlet cabin  321 ), it is limited by the recess  3211  of the air chamber box  32  so as to form a compressed state so that the air is forced to pass through a gap  33  defined between the recess  3211  and the air inlet guide hole  3111  to flow into the first chamber  311  (mating with the air inlet cabin  321 ). 
     The air is then introduced into the second chamber  312  (mating with the first circuitous chamber  322 ) through the guide hole  317  between the first chamber  311  and the second chamber  312 . 
     When the air is introduced into the air inlet chamber  211  of the body  21  from the air inlet chamber air inlet hole  3121  of the second chamber  312 , the catch plate  3221  of the first circuitous chamber  322  of the air chamber box  32  will form an obstruction so that the air is forced to pass through the gap  34  defined between the catch plate  3221  and the air inlet chamber air inlet hole  3121  to be introduced into the air inlet chamber  211  of the body  21  through the air input hole  2111  to flow in the body  21 . 
     The air then flows into the air outlet chamber  212 , and is then introduced into the third chamber  313  (mating with the second circuitous chamber  323 ) through the air output hole  2121 . 
     When the air is introduced into the third chamber  313 , the catch plate  3231  of the second circuitous chamber  323  of the air chamber box  32  will form an obstruction so that the air is forced to pass through the gap  36  defined between the catch plate  3231  and the air outlet chamber air outlet hole  3131  to be introduced into the third chamber  313  (mating with the second circuitous chamber  323 ) whereby the air is compressed again so that the air will flow in the third chamber  313  (mating with the second circuitous chamber  323 ), and is then introduced into the fourth chamber  314  (mating with the air guide chamber  324  through the guide hole  327 . The air is then drained outward from the air outlet tube  26  of the body  21  through the air conveying hole  3141 . 
     Accordingly, the sound elimination structure of the invention can be used to increase the flow path of the air, and to reduce the flowing velocity of the air by provision of the recesses and the plurality of catch plates, thereby efficiently reducing or eliminating the noise of created by the air pump. 
     Referring now to FIGS. 6-9, in accordance with another embodiment of the present invention, the air chamber cover  41  is separated by a plurality of baffles  415  into a first chamber  411 , a second chamber  412 , a third chamber  413 , and a fourth chamber  414 , wherein the third chamber  413  connects to the fourth chamber  414 . An air guide tube  4111  is mounted in the first chamber  411  and connects to an external air extraction hole  416 . An air inlet chamber air inlet hole  4121  is defined in the second chamber  412  and connects to the air inlet chamber  211  of the body  21 . An air outlet chamber air outlet hole  4131  is defined in the third chamber  413  and connects to the air outlet chamber  212  of the body  21 . An air conveying hole  4141  is defined in the fourth chamber  414  and connects to an air outlet tube  26  of the body  21 . A guide hole  417  is defined between the first chamber  411  and the second chamber  412 . 
     The air chamber box  42  is separated by a plurality of baffles  425  into an air inlet cabin  421 , a first circuitous chamber  422 , a second circuitous chamber  423 , and an air guide chamber  424 . A first lug  4211  is mounted in the air inlet cabin  421  and is loosely fitted in the air guide tube  4111  of the first chamber  411  of the air chamber cover  41 . A second lug  4221  is mounted in the first circuitous chamber  422  and is loosely fitted in the air inlet chamber air inlet hole  4121  of the second chamber  412  of the air chamber cover  41 . 
     Accordingly, the sound elimination structure of the invention can be used to reduce the flowing velocity of the air by provision of the lugs  4211  and  4221 , thereby efficiently reducing or eliminating the noise of created by the air pump. 
     Referring to FIGS. 10-12, in accordance with a further embodiment of the present invention, the air chamber box  51  and the air chamber cover  52  are provided two sets of air flow paths to co-operate with two sets of vibration cranks  53  and two sets of compression cups  54  so as to form two sets of corresponding air pumps  50 . 
     It should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.