Abstract:
An elaborately designed miniature air compressor is composed of a motor unit, a compression unit, and an air collection unit. Several bladders installed in the compression unit are sequentially actuated by a compression vane with a thrust and pulling force imparted from priston like motion caused by revolution of an eccentrically installed follower rod such that air is continuously supplied to the air collection unit and ejected out of an air output port uniformly, stably, and adequately. Besides, all component units of the miniature air pump are combined together by two shackles in stead of using latch pins.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the invention 
     The present invention relates to a miniature air pump with an innovative structure, and more particularly, to a miniature air pump which can optionally choose the number of air bladders, and improve pump structure so as to stabilize the air output of the pump. 
     2. Description of the Prior Art 
     A conventional miniature air pump can only produce compressed air, and perform air intake and output function with a defined air chamber. Such a simply constructed miniature air pump often causes an unsmooth air flow due to its inherent shortcomings in the structural design. 
     For example, a well known conventional electronic sphy gmomanometer in the world requires installation of an outer check valve to refuse back flow of high pressure air into the pump so as to prevent measurement error. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a miniature air pump which can optionally choose the number of air chambers, and improve pump structure and function. 
     It is another object of the present invention to provide a miniature air pump which can be formed into a compact size and many pleasant contours for customers free choice. 
     It is still another object of the present invention to provide a miniature air pump whose bladders are able to sequentially output pressurized air from an air output hole after introducing the air into the pump via an air pathway, and also able to prevent the back flow of air with a membrane functioning as a check valve. 
     These and other objects of the miniature air pump according to the present invention comprises a motor unit, a compression unit, and an air collection unit. 
     Wherein, the motor unit further includes a main motor portion, a base, and a rotor portion. A rotating shaft which being extended out of the main motor portion tunnels through the base and is coupled with the rotor portion whereat an eccentric hole is provided. Several air inlet apertures are formed at the side of the base. 
     The compression unit further includes a compression vane, a fixture, and several compression chambers. A follower rod which being extended out of the center of the compression vane is inserted into the eccentric hole formed on the rotor portion with a predetermined offset angle. The compression chamber is composed of a bladder, a flow check membrane, and a leak proof gasket. Each compression chamber is conjoined with the compression vane by a tenon formed at the rear of each bladder mated with a corresponding mortise eye formed on the compression vane after tunneling through the fixture. A first check valve is installed on the fixture facing to the flow check membrane for each compression chamber. 
     The air collection unit has several flow pathways corresponding to the bladders, several membranes functioning as second check valves are equipped at each exit side of the flow pathway, several guide slots each formed between the first check valve and the bladder, and an air output port is formed at the topmost end thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To enable a further understanding of the innovative and technological content of the invention herein, refer to the detailed description of the invention and the accompanying brief description of the drawings appended below. Furthermore, the attached drawings are provided for purposes of reference and explanation, and shall not be con strued as limitations applicable to the invention herein. 
     FIG. 1 is a three dimensional exploded view of the present invention; 
     FIG. 2 is a schematic view of the motor unit of the present invention; 
     FIG. 3 is a schematic view of the compression unit of the present invention; 
     FIG. 4 is a schematic view of the collection unit of the present invention; 
     FIG. 5 is an assembly view of the miniature air pump of the present invention; 
     FIGS.  6 (A) to  6 (D) drawings illustrating various kinds of planar views whereby a compression chamber is configurated in the miniature air pump of the present invention; 
     FIGS. 7A to  7 B are drawings illustrating operational principle in the miniature air pump of the present invention; 
     FIGS. 8A and 8B are illustrating two different types of latching means used for conjoining all three units of the present invention together; and 
     FIG. 9 is a plan view illustrating relative positions among the compression chamber, the leak proof gasket, and the check flow membrane. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, the three dimensional exploded view of the present invention shows that the contour of the miniature air pump is formed into a cylindrical configuration. The miniature air pump comprises a motor unit  10 , a compression unit  20 , and an air collection unit  30 . Several latch pins  40  are applied from outside to conjoin all three aforementioned units together. 
     The motor unit  10  further includes a main motor portion  101 , a base  103 , and a rotor portion  104 . FIG. 2 is its assembled view. 
     The compression unit  20  further includes a compression vane  201 , a fixture  204 , and several compression chambers  208 . A follower rod  202  is extended from the center of the compression vane  201  and inserted into an eccentric hole  105  formed on the rotor portion  104  with a predetermined offset angle. The compression chamber  208  is composed of a bladder  207 , a check flow membrane  209 , and a leak proof gasket  210 . In FIG. 1, three bladders disposed symmetrically apart from each other with 120° are used for improving compressed air output or particular requirement. The compression chambers  208  are conjoined with the compression vane  210  by tenons  206  each formed at the rear of respective bladder mated with corresponding mortise eye  203  formed on the compression vane  201  after tunneling through the fixture  204 . A first check valve  205  is installed on the fixture  204  facing to the check flow membrane  209  for each compression chamber  208 . The compression vane  201  is divided into three sub-blades each inclining upward with a predetermined angle. 
     The main motor portion  101  is engaged with its base  103 , a rotating shaft  102  is extended out of the main motor portion  101 , and after tunneling through the base  103 , is coupled with the rotor portion  104 . Several air inlet apertures  106  are formed at the side of the base  103 . After the motor unit  10  is energized, the rotor portion  104  rotates rapidly along with the follower rod  202  which being inserted into the eccentric hole  105 . Several steel balls are provided in the eccentric hole  105  for preventing excessive abrasion of the follower rod  202  caused by friction. 
     Referring to FIG. 3, this drawing shows the assembled view of the compression unit in which the follower rod  202  has been already inserted into the eccentric hole  105  of the rotor portion  104 . The follower rod  202  revolves eccentially by the motor unit  10  and drives the compression vane  201  to rotate which in turn sequentially equesszes all bladders  207  with a thrust force imparted from the follower rod. The bladders  207  then supplies the produced air into the air collection unit  20 . With such structure and the aid of the friction reducing steel balls in the eccentric hole  105 , the driving power can be saved a great deal. 
     For more detailed description about the operational principle of the present invention, reference should be made to FIGS. 7A and 7B together with FIGS. 3 and 4. FIGS. 7A and 7B illustrate operational principle of a two-bladder pump of the present invention. In the state shown in FIG. 7A, the upper bladder  207  is in full state, the upper first valve  205  is closed by inner pressure of the upper compression chamber  208 , and this same pressure forces the upper flow check membrane  302  to open and from a pathway  301  around its periphery such that air stored in the upper comprission chamer  208  is supplied to the air collection unit  30  therethrough and ejected out of the air output hole  303 . On the other hand, the lower bladder  207  is in squeezed and deformed state, the reduced inner pressure of the lower compression chamber  208  causes the lower first check valve  205  to open and allows the outside air to flow into the lower compression chamber  208  via the plurality of air inlet apertures  106 . On the other hand, in FIG. 7B, an exactly reversed state to that of FIG. 7A happens. Such motions are alternatively and repeatedly continued until the motor unit  10  stops driving the compression vane  201 . 
     By successively and sequentially squeezing all bladders  207  one by one, the air can continuously flow through the pathway  301  and is uniformly ejected out of the air output port  303 . The membrane  302  can function as a check valve to prevent back flow of air from the pathway  301 . 
     Referring to FIG. 5 the miniatuture air pump after assembling is engaged with several latch pins  40  from outside. The leak proof gasket  210  interposed between the compression unit  20  and the air collection unit  30  may preserve a constant pressure inside the pump and maintain a stable amount of air output as well. 
     According to operational principles described above, any number of bladders and any forms of arrangement for the bladders are optionally applicable as long as the compression chambers may be symmetrically disposed as shown in FIG.  9 . In FIG. 9, relative positions among the compression chamber  208 , the leak proof gasket  210 , and the flow check membrane are shown in a plan view. As it is clearly shown, each compression chamber  208  is disposed 120° apart from the adjacent one so that the arrangement fulfils the aforesaid principles of uniformity and symmetry. Besides, referring to FIGS. 6A through 6D, two or more than two bladders are employed with a contour configurated in square, ellipse, circle, or rectangle in planar view. Other corresponding parts can be designed to match for. 
     Finally, referring to FIG. 8A, for achieving pinless construction, a pair of U shaped shackles  50  are used to combine all units of the present invention together. Two hooks  51  flexed in opposite direction are stretched from two ends of the shackle  50  to hook respectively on two hasps  52  formed on the rim of the top surface of the assembly. In this way the component units of various sizes and shapes can be engaged together with two U shaped shackles  50 . FIG. 8A shows two U shaped shackles  50  are used to engage all three units of a cylindrical pump together by inlaying two shackle bodies  53  in the grooves  60  formed on the outer surface of the assembly. Similarly, FIG. 8B shows two U shaped shackles  70  are used to engage all three units of a pump formed in a rectangular prismatic contour by inlaying two shackle bodies  73  in the grooves  80  formed on the outer surface of the assembly, and engaging hooks  71  with the hasps  72  in similar way as that of FIG.  8 A. 
     From the above detailed description of the present invention, it will be clear that the miniature air pump according to the present invention has many advantages that the number of air chambers is optionally selective to form the pump structure into a compact size and many pleasant contours, and also can improve the pump function to supply compressed air stably and with a uniform flow. 
     Other embodiments of the present invention will become obvious to those skilled in the art in light of above disclosure. It is of course also understood that the scope of the present invention is not to be determined by the foregoing description, but only by the following claims.