Abstract:
An air pump operably by a motor to pump air is disclosed to include a body, an airbag unit, which is mounted in the body has multiple airbags each having an air chamber and an air inlet, a lifting mechanism rotatable by the motor to move the airbags to pump air, a plurality of air intake control valves movably set between the air inlet of each airbag and respective air inlets of the lifting mechanism to control the air passage between the air inlet of each airbag and the air inlets of the lifting mechanism subject to the operation status of the airbags, and an exhaust structure coupled to the airbag unit for exhaust of air from the airbags.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to air pumps and more particularly, to an air pump having an improved air intake control structure.  
         [0003]     2. Description of the Related Art  
         [0004]     A conventional air pump is known comprising an airbag unit, which defines therein a plurality of air chambers, a partition plate, which has exhaust holes and air inlets respectively disposed in communication with the air chambers, a control valve, which has air inlet control valve flaps and exhaust control valve flaps corresponding to the exhaust holes and the air inlets, a crank, which has air inlets corresponding to the air inlet control valve flaps and the exhaust control valve flaps. When started the motor, the airbags are moved to suck in air through the air inlets and to force air out of the exhaust holes.  
         [0005]     The aforesaid prior art air pump has a complicated structure formed of a big number of parts, resulting in a complicated installation procedure and high manufacturing cost. Further, this design of air pump is not convenient in use.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide an air pump, which has a simple air intake structure. It is another objects of the present invention to provide an air pump, which has the air intake structure provided at the bottom side convenient for intake of air.  
         [0007]     To achieve these and other objects of the present invention, the air pump is coupled to a motor and adapted to pump air upon rotation of the motor. The air pump comprises a body; an airbag unit mounted in the body, the airbag unit comprising at least one airbag, the at least one airbag each having an air chamber and an air inlet; a lifting mechanism rotatable by the motor, the lifting mechanism having at least one arm respectively connected to the at least one airbag and adapted to move the at least one airbag to pump air, and at least one air inlet in air communication with the air inlet of each airbag; air intake control valve means movably set between the air inlet of each airbag and the at least one air inlet of the lifting mechanism to control the air passage between the air inlet of each airbag and the at least one air inlet of the lifting mechanism; and an exhaust structure coupled to the airbag unit for exhaust of air from the at least one airbag. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is an exploded view of an air pump in accordance with a first embodiment of the present invention.  
         [0009]      FIG. 2  is a plain view in an exploded status of the air pump according to the first embodiment of the present invention.  
         [0010]      FIG. 3  is an exploded view of a part of the air pump according to the first embodiment of the present invention.  
         [0011]      FIG. 4  is a sectional view in an exploded status of a part of the air pump according to the first embodiment of the present invention.  
         [0012]      FIG. 5  is a sectional assembly view of the air pump according to the first embodiment of the present invention.  
         [0013]      FIG. 6  is similar to  FIG. 5  but showing the air pump operated.  
         [0014]      FIG. 7  is an exploded view of a part of an air pump in accordance with a second embodiment of the present invention.  
         [0015]      FIG. 8  is a sectional view in an exploded status of a part of the air pump according to the second embodiment of the present invention.  
         [0016]      FIG. 9  is a sectional assembly view of the air pump according to the second embodiment of the present invention.  
         [0017]      FIG. 10  is similar to  FIG. 9  but showing the air pump operated.  
         [0018]      FIG. 11  is an exploded view of a part of an air pump in accordance with a third embodiment of the present invention.  
         [0019]      FIG. 12  is a sectional view in an exploded status of a part of an air pump in accordance with the third embodiment of the present invention.  
         [0020]      FIG. 13  is a sectional assembly view of the air pump according to the third embodiment of the present invention.  
         [0021]      FIG. 14  is similar to  FIG. 13  but showing the air pump operated. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     Referring to  FIG. 16 , an air pump in accordance with a first embodiment of the present invention is shown movable with the shaft M 2  of a motor M to pump air. The air pump comprises a body formed of a holder  10  and a cover  20 , an airbag unit  30 , a lifting mechanism formed of a crank  40  and a rotary member  50 , and an exhaust unit formed of a partition plate  70  and an exhaust control valve  80  and an exhaust cap  90 .  
         [0023]     The holder  10  is affixed to the motor M with two screw bolts B 1 , having a holder body  11  defining a receiving open chamber  12 , a through hole  14  cut through the center of the bottom wall thereof in communication with the receiving open chamber  12  for the passing of the shaft M 2  of the motor M, and three mounting portions (mounting holes)  19 .  
         [0024]     The cover  20  has a cover body  21  covered on the holder body  11  of the holder  10  to close the receiving open chamber  12 , three mounting portions (mounting holes)  29  formed in the cover body  21  corresponding to the mounting portions  19  of the holder  10 , and three airbag receiving portions (airbag receiving holes)  23  formed in the cover body  21 .  
         [0025]     The airbag unit  30  has a mounting plate  31 , and three airbags  33  connected to the mounting plate  31  and respectively received in the airbag receiving portion  23  of the cover  20 . Each airbag  33  has an air chamber  34 , a coupling portion  35 , an air inlet  38 , and an integrated valve flap  37  which formed an air intake control valve adapted to control the air inlet  38 .  
         [0026]     The crank  40  has a shaft  41 , which has an axial hole  42 , three arms  43  extended from the shaft  41  and respectively connected to the coupling portions  35  of the airbags  33  of the airbag unit  30 . Each arm  43  has a head  45  coupled to the coupling hole  35  of one airbag  33 , a plurality of air inlets  46  cut through the head  45 , and a bearing surface  48  formed on the top side of the head  45  for stopping against the valve flap  37  of the associating airbag  33 .  
         [0027]     The rotary member  50  has a base  51  connected to the shaft M 2  of the motor M for rotation with the shaft M 2 , and an oblique shaft  53  obliquely extended from the base  51  and coupled with a steel ball  55  to the axial hole  42  of the shaft  41  of the crank  40 .  
         [0028]     The partition plate  70  has a body  71  connected to the top side of the mounting plate  31  of the airbag unit  30 , three exhaust holes  72  respectively disposed in air communication with the air chambers  34  of the airbags  33  of the airbag unit  30 , and three mounting portions  79  respectively fastened to the mounting portions  29  of the cover  20 .  
         [0029]     The exhaust control valve  80  has a valve body  81  fastened to the partition plate  70 , three smoothly arched valve flaps  82  respectively protruded from the valve body  81  and adapted to close/open the exhaust holes  72  of the partition plate  70 , and three mounting portions  89 .  
         [0030]     The exhaust cap  90  has a cap body  91 , a chamber  92  defined in the cap body  91  corresponding to the valve flaps  82  of the exhaust control valve  80 , three press portions  93 , an exhaust hole  95  in air communication with the chamber  92 , and three mounting portions  99 .  
         [0031]     Further, three screw bolts B 3  are inserted through the mounting portions  99 ,  89 ,  79  and  29  of the exhaust cap  90 , exhaust control valve  80 , partition plate  70  and cover  20  and fastened to the mounting portions  19  of the holder  10  to affix the related parts together.  
         [0032]     Referring to  FIG. 5 , when the motor M is started to rotate the rotary member  50 , the oblique shaft  53  of the rotary member  50  drives the crank  40 , causing the arms  43  of the crank  40  to reciprocate the airbags  33  alternatively.  
         [0033]     Referring to  FIG. 5  again, when one airbag  33  is moved downwards, it breathes in air, and the associating valve flap  82  is forced by the suction force to close the associating exhaust hole  72  of the partition plate  70 , and at the same time the associating valve flap  37  curved upwards and spaced from the head  45  of the associating arm  43  of the crank  40  for allowing air to pass through the associating air inlets  46  into the associating air chamber  34 .  
         [0034]     On the contrary, as shown in  FIG. 6 , when one airbag  33  is moved upwards, the associating valve flap  37  is forced by air pressure to stop at the head  45  of the associating arm  43  of the crank  40  and to further block the passage between the associating air inlets  46  and the associating air chamber  34 , and at the same time the associating valve flap  82  is forced by the air pressure to open the associating exhaust hole  72  of the partition plate  70  for enabling air to pass through the associating exhaust hole  72  of the partition plate  70  and the chamber  92  of the exhaust cap  90  to the outside via the exhaust hole  95 .  
         [0035]      FIGS. 7 and 8  show an air pump in accordance with a second of the present invention. This embodiment includes three air intake control valves  60 A. The crank  40 A has a plurality of installing portions  47 A, and a plurality of air inlets  46 A corresponding to the installing portions  47 A. Each air intake control valve  60 A has a mounting portion  61 A fastened to one installing portion  47 A of the crank  40 A, a valve flap  63 A adapted to close/open one air inlet  46 A of the crank  40 A.  
         [0036]     Referring to  FIG. 9 , the air inlets  46 A of the crank  40 A are adapted to suck in air. When one air inlet  46 A is stopped against the associating valve flap  63 A of the air intake control valve  60 A, the associating valve flap  63 A is deformed, and the air inlet  46 A is opened for letting air to pass. On the contrary, as shown in  FIG. 10 , during exhaust stroke, the valve flaps  63 A are respectively closed on the associating air inlets  46 A to block the air inlets  46 A, for enabling air to exhaust upwards.  
         [0037]      FIGS. 11 and 12  show an air pump in accordance with a third embodiment of the present invention. According to this embodiment, the crank  40 B has a plurality of installing portions  47 B and a plurality of air inlets  46 B corresponding to the installing portions  47 B; the air intake control valves  60 B each have a valve flap  63 B respectively and elastically deformably covered on the air inlets  46 B, and a floating portion  65 B formed integral with a part of the valve flap  63 B.  
         [0038]     As shown in  FIG. 13 , when breathing in air, the air inlets  46 B are respectively stopped against the floating portions  65 B of the air intake control valves  60 B to letting air pass. On the contrary, as shown in  FIG. 14 , when exhausting air, the air intake control valves  60 B are forced downwards by air pressure to close the valve flaps  63 B on the associating air inlets  46 B.  
         [0039]     In the aforesaid various embodiments of the present invention, the lifting mechanism can be fastened to the airbag unit by a plug joint, hook joint or rivet joint, or with an adhesive, or by means of any of a variety of connection means.  
         [0040]     As indicated above, the air pump of the present invention has the following benefits:  
         [0041]     1. The air intake structure of the air pump is provided at the bottom side convenient for intake of air. It can be tightly sealed during the exhaust stroke.  
         [0042]     2. The arrangement of the intake structure of the air pump is simple.