Abstract:
A dual-gauge air pump has two round dial pressure gauges that are configured in a back-to-back arrangement, i.e. 180 degrees to each other, and to rotate through 360 degrees simultaneously for a user&#39;s easy observation.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation-in-part (CIP) application of Ser. No. 13/926431 filed on Jun. 25, 2013 entitled “AIR PUMP WITH TWO PRESSURE GAUGES FOR HIGH/LOW PRESSURE INDICATION”. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to manual air pumps, and more particularly to a dual-gauge air pump. 
         [0004]    2. Description of Related Art 
         [0005]    U.S. Pat. No. 5,779,457 discloses a mini manual pump that having low- and high-pressure gauges. Each of the gauges has a bar-like shape and very fine calibrations. In use, a user read a pressure value by visually determining a present site of the moving piston in one of the narrow windows and identifying the corresponding calibration. This is particularly challenging to users having poor vision. Also, the two juxtaposed gauges may cause confusion to users about which one is to be read right now 
       SUMMARY OF THE INVENTION 
       [0006]    The primary objective of the present invention is to provide a dual-gauge air pump whose pressure value is convenient and easy to read. 
         [0007]    To achieve the foregoing objective, the disclosed dual-gauge air pump features for two round dial pressure gauges that are configured in a back-to-back arrangement, i.e. 180 degrees to each other, and to be rotate through 360 degrees simultaneously for a user&#39;s easy observation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an exploded view of the first embodiment of present invention. 
           [0009]      FIG. 2  is a cross-sectional view of the first embodiment of present invention. 
           [0010]      FIG. 3  is a side view of a portion of the first embodiment of present invention. 
           [0011]      FIG. 4  is a cross-sectional view along the  4 - 4  line in  FIG. 3 . 
           [0012]      FIG. 5  is a cross-sectional view along the  5 - 5  line in  FIG. 4 . 
           [0013]      FIG. 6  is a front view of the second embodiment of present invention. 
           [0014]      FIG. 7  is a top view of the second embodiment of present invention. 
           [0015]      FIG. 8  is a cross-sectional view along the  8 - 8  line in  FIG. 7   
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    For further illustrating the present invention, two preferred embodiments are described below with reference to the accompanying drawings. 
         [0017]    Referring to  FIG. 1  through  FIG. 5 , according to the first embodiment of the present invention, a mini air pump ( 10 ) comprises: 
         [0018]    a barrel ( 11 ); 
         [0019]    a piston ( 12 ), installed in the barrel ( 11 ): 
         [0020]    a pumping shaft ( 13 ), having one end fixed to the piston ( 12 ) and an opposite end jutting out one end of the barrel ( 11 ); 
         [0021]    a handle ( 14 ), being fixed to an opposite end of the pumping shaft ( 13 ); 
         [0022]    a gauge casing ( 15 ), having one end fixed to an opposite end of the barrel ( 11 ) and being provided with two round dial pressure gauges ( 20 )( 30 ), in which one is a high-pressure gauge ( 20 ) and the other is a low-pressure gauge ( 30 ), wherein the two pressure gauges ( 20 )( 30 ) are on each other&#39;s back, facing the exterior, and communicated with the barrel ( 11 ) through air paths ( 21 )( 31 ) respectively; and 
         [0023]    a nozzle casing ( 16 ), being pivotally connected to an opposite end of the gauge casing ( 15 ) and freely rotatable through 360 degrees, containing therein a nozzle assembly ( 40 ), and being communicated with the barrel ( 11 ) through an air path ( 41 ). 
         [0024]    Before use, a user decides whether the high-pressure gauge or the low-pressure gauge is used, and makes the selected gauge face him/her. Then the user can connect the nozzle ( 40 ) to a valve provided on an object to be inflated. The use is convenient. Additionally, since the gauges are round dial pressure gauges, the indication is very clear and can be easily read by the user. 
         [0025]    As shown in  FIG. 6  through  FIG. 8 , in the second embodiment of the present invention, a floor pump ( 50 ) comprises: 
         [0026]    a barrel ( 51 ); 
         [0027]    a piston ( 52 ), installed in the barrel ( 51 ); 
         [0028]    a pumping shaft ( 53 ), having one end fixed to the piston ( 52 ) and an opposite end jutting out one end of the barrel ( 51 ); 
         [0029]    a handle ( 54 ), being fixed to an opposite end of the pumping shaft ( 53 ); 
         [0030]    an air guide ( 55 ), being installed in the barrel ( 51 ) and having an exposed end ( 551 ); 
         [0031]    a hose ( 56 ), having one end fixed to an exposed end ( 551 ) of the air guide ( 55 ); 
         [0032]    a nozzle ( 57 ), being fixed to an opposite end of the hose ( 56 ); 
         [0033]    an air-guiding path ( 58 ), being communicated with the air guide ( 55 ); and 
         [0034]    a gauge casing ( 60 ), being provided with two round dial pressure gauges ( 70 )( 80 ), in which one is a high-pressure gauge ( 70 ) and the other is a low-pressure gauge ( 80 ) that are on each other&#39;s back and facing the exterior, and having laterally a post ( 61 ) that is formed centrally an air path ( 62 ) running from the exterior to the interior, wherein the two dial pressure gauges ( 70 )( 80 ) are communicated with the air path ( 62 ) respectively and the gauge casing ( 60 ) has its post ( 61 ) pivotally connected to the air-guiding path ( 58 ) so as to be freely rotatable through 360 degrees. 
         [0035]    Thereby, a user can rotate the gauge casing ( 60 ) to conveniently select whether he/she uses the high-pressure gauge ( 70 ) or the low-pressure gauge ( 80 ).