Abstract:
A dual duty hand pump has two air channels, a hand grip, a piston rod, a piston, a deflating unit and an inflating unit. The hand grip and the piston are mounted on two ends of the piston rod. The deflating unit and the inflating unit are respectively mounted in the air channels and respectively have two check valves mounted therein in two opposite directions. When the hand grip is lifted and pressed down, air respectively flows in and flows out of the hand pump through the air channel. Accordingly, the hand pump provides a practical and convenient solution to integrate inflating and deflating functions as a whole for users to flexibly select from when the dual duty hand pump is in use.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an air pump, and more particularly to a dual duty hand pump integrating inflating and deflating functions as a whole. 
         [0003]    2. Description of the Related Art 
         [0004]    A lot of daily objects need inflating or deflating to function properly. For example, packing bags for clothes, pillows or blankets, need to be rapidly deflated so as to tightly wrap up the packed things and keep away dirt and moisture. Other things, such as tires, balloons, balls, need to be inflated to become useful. Certain things, such as bicycle tires, need to be inflated and deflated to maintain a comfortable cycling condition. In a case that both manual inflation and deflation are needed, a hand pump and a hand suction pump respectively dedicated to inflate and deflate need to be at hand. Preparing both tools at the same time is inconvenient. Consequently, it is inconvenient when a user needs to deal with inflating and deflating objects at the same time. 
       SUMMARY OF THE INVENTION 
       [0005]    An objective of the present invention is to provide a dual duty hand pump integrating inflating and deflating functions as a whole. 
         [0006]    To achieve the foregoing objective, the dual duty hand pump has a hand grip, a pump body, a piston rod, a piston, a deflating unit and an inflating unit. The pump body is hollow and has a through hole, an air inlet channel, and an air outlet channel. The through hole is formed through one end of the pump body. The air inlet channel and the air outlet channel are formed through the other end of the pump body and communicating with the through hole. 
         [0007]    The piston rod is mounted in the pump body and through the through hole of the pump body. One end of the piston rod is connected with the hand grip. 
         [0008]    The piston is securely mounted on the other end of the piston rod, and has a seal ring hermetically mounted on an inner wall of the pump body. 
         [0009]    The deflating unit is mounted in the air inlet channel and has a check valve through which air flows in a first direction. 
         [0010]    The inflating unit is mounted in the air outlet channel and has a check valve through which air flows in a second direction opposite to the first direction. 
         [0011]    When the hand grip is pulled, air enters the pump body through the air inlet channel and the check valve mounted inside the air inlet channel. When the hand grip is pushed, air flows out of the pump body through the air outlet and the check valve. Therefore, if an inflated object is connected to the air inlet channel, air inside the inflated object can be deflated to the pump body and exhausted out of the pump body through the air outlet channel. If an inflatable object is connected to the air outlet channel, air entered the pump body through the air inlet channel can inflate the inflatable object through the air outlet channel. The dual duty hand pump provides a solution integrating both deflating and inflating functions as a whole for users to flexibly select from when the dual duty hand pump is in use. 
         [0012]    Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of a first embodiment of a dual duty hand pump in accordance with the present invention; 
           [0014]      FIG. 2  is a side view in partial section of the hand pump in  FIG. 1 ; 
           [0015]      FIG. 3  is an exploded perspective view of a pump body, a deflating unit, an inflating unit and a base of the hand pump in  FIG. 1 ; 
           [0016]      FIG. 4  is an exploded perspective view of the deflating unit and the inflating unit in  FIG. 3 ; 
           [0017]      FIG. 5  is an enlarged operational side view in partial section of the hand pump in  FIG. 1  when the hand pump is deflating; 
           [0018]      FIG. 6  is an enlarged operational side view in partial section of the hand pump in  FIG. 1  when the hand pump is inflating; 
           [0019]      FIG. 7  is a side view in partial section of .a second embodiment of a dual duty hand pump in accordance with the present invention; and 
           [0020]      FIG. 8  is a side view in partial section of a third embodiment of a dual duty hand pump in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    With reference to  FIGS. 1 and 2 , a first embodiment of a dual duty hand pump in accordance with the present invention has a pump body  10 , a piston rod  20 , a hand grip  21 , a piston  30 , a deflating unit  4  and an inflating unit  5 . 
         [0022]    The pump body  10  is hollow and elongated, and has an opening, a cover  11 , a through hole  12  and a base  13 . The bpening is formed through one end of the pump body  10 . The cover  11  covers and seals the opening. The through hole  12  is formed through the cover  11 . The base  13  is mounted on the other end of the pump body  10  and has an air inlet channel  14  and an air outlet channel  15 . The air inlet channel  14  and the air outlet channel  15  are formed through the base  13 . 
         [0023]    The piston rod  20  is mounted in the pump body  10  and through the through hole  12  of the cover  11  of the pump body  10 . The hand grip  21  is securely mounted on one end of the hand grip  21  outside the pump body  10 . The piston  30  is securely mounted on the other end of the piston rod  20  and has an annular slot  31  and a seal ring  32 . The annular slot  31  is formed in a periphery of the piston  30 . The seal ring  32  is mounted in the annular slot  31  and is hermetically attached on an inner wall of the pump body  10 . 
         [0024]    With reference to  FIGS. 3 to 5 , the deflating unit  4  is mounted in the air inlet channel  14  of the pump body  10 , and has a check valve  40 , a blocking plate  46  and a gasket  41 . The check valve  40  has a valve seat  42 , an air vent cover  43  and a valve plate  44 . The valve seat  42  is hollow and tubular, and has a valve gate  45 , a top opening, a bottom opening and an enlarged head  420 . The valve gate  45  is formed on and protrudes radially from an inner wall of the valve seat  42  to partition an inner space of the valve seat  42  into an upper compartment and a lower compartment, and has a gate hole  450  formed through the valve gate  45 . The top opening is formed through a top of the valve seat  42 . The bottom opening is formed through a bottom of the valve seat  42 . The enlarged head  420  is formed on an upper portion of a periphery of the valve seat  42  and has expanded outer and inner diameters. An outer wall of the enlarged head  420  abuts against an inner wall of the air inlet channel  14  to hermetically seal an inner end of the air inlet channel  14 . The air vent cover  43  is mounted in the upper compartment of the enlarged head  420  and has an air vent hole  430  and multiple stoppers  431 . The air vent hole  430  is formed through the air vent cover  43 . The stoppers  431  are formed on and protrude from one side of the air valve cover  43  facing the valve gate  45 , and are spaced with an interval between each other. The valve plate  44  is movably mounted between the stoppers  431  and the valve gate  45 , and has an outer diameter smaller than an inner diameter of the inner wall of the valve seat  42 . The blocking plate  46  is mounted underneath the check valve  40 , aligns with the bottom opening of the valve seat  42 , hermetically abuts against the inner wall of the air inlet channel  14 , and has an air hole  460  formed through the blocking plate  46 . The gasket  41  is mounted underneath the blocking plate  46  to hermetically seal the bottom opening of the air inlet channel  14 , and has an air hole  410  formed therethrough and communicating with that of the blocking plate  46 . 
         [0025]    The inflating unit  5  is mounted in the air outlet channel  15 , and has a check valve  50  and a gasket  51 . The check valve  50  may be structurally identical to the check valve  40  in the deflating unit  4  while aligning in a direction reverse to that in the deflating unit  4 . 
         [0026]    The check valve  50  of the inflating unit  5  has a valve seat  52 , an air vent cover  53  and a valve plate  54 . The valve seat  52  is hollow and tubular, and has a top opening, a bottom opening, a valve gate  55  and an enlarged head  520 . The valve gate  55  is formed on and protrudes radially from an inner wall of the valve seat  52  to partition an inner space of the valve seat  52  into an upper compartment and a lower compartment. The valve gate  55  has a gate hole  550  formed through the valve gate  55 . The enlarged head  520  is formed on a lower portion of a periphery of the valve seat  52  and has expanded outer and inner diameters. An outer wall of the enlarged head  520  abuts against an inner wall of the air outlet channel  15  to hermetically seal an Outer end of the air outlet channel  15 . The air vent cover  53  is mounted in the lower compartment of the enlarged head  520  and has an air vent hole  530  and multiple stoppers  531 . The air vent hole  530  is formed through the air vent cover  53 . The stoppers  531  are formed on and protrude from one side of the air valve cover  53  facing the valve gate  55 , and are spaced with an interval between each other. The valve plate  51  is movably mounted between the stoppers  531  and the valve gate  55 , and has an outer diameter smaller than an inner diameter of the inner wall of the valve seat  52 . The gasket  51  is mounted underneath the check valve  50  to hermetically seal the bottom opening of the air outlet channel  15 , and has an air hole  510  formed through the gasket  51  and communicating with the air vent hole  530  of the air valve cover  53 . 
         [0027]    The gaskets  41 ,  51  of the deflating unit  4  and the inflating unit  5  are made of plastic or other substitute material. The valve seats  42 ,  52  of the check valves  40 ,  50  are made from Acrylonitrile Butadiene Styrene (ABS) Copolymer or other substitute material. The blocking plate  46  of the deflating unit  4  is made of plastic or other substitute material. 
         [0028]    The deflating unit  4  and the inflating unit  5  further respectively have connection rings  400 ,  500 . Each of the connection rings  400 ,  500  is securely mounted in the air inlet channel  14  or the air outlet channel  15 , is adjacent to the bottom opening of the air inlet channel  14  or the air outlet channel  15 , and has a threaded hole engaging an air pin to inflate or deflate an inflatable object. 
         [0029]    With reference to  FIG. 5 , during the deflation, the connection ring  400  of the deflating unit  4  engages an air pin mounted through an inflatable object first. The hand grip  21  is held and pulled upwardly so that the piston rod  20  is moved upwardly and air enters the pump body  10 . The valve plate  44  of the check valve of the deflating unit  4  is pushed by air to move upwardly and abut against the stoppers  431  of the air vent cover  43 . Air sequentially passes through the air holes  410 ,  460  of the gasket  41 , the blocking plate  46  to enter the valve seat  42 . As the gate hole  450  in the valve seat  42  is open, air can further pass through the gate hole  450 , flow to the space between the stoppers  431  of the air vent cover  43 , and enter the pump body  10 . Meanwhile, the valve plate  54  of the check valve  50  of the inflating unit  5  is pushed by air outside the pump body  10  to move upwardly so that the valve plate  54  abuts against the valve gate  55  in the valve seat  52  and seals the gate hole  550 , and air is unable to enter the pump body  10  through the air outlet channel  5 . 
         [0030]    With reference to  FIG. 6 , when the hand grip  21  is pushed and the piston rod  20  is moved downwardly, the valve plate  44  of the deflating unit  4  is pushed by air to move downwardly and seal the gate hole  450  so that air will not flow out through the air inlet channel  14 . The valve plate  54  of the inflating unit  5  is pushed by air to move downwardly and abut against the stoppers  531  of the air vent cover  53 . Hence, air can pass through the gate hole  550  of the valve seat  52  and flow to the space between the stoppers  531  of the air vent cover  53 , and flow out of the pump body  10  through the air vent hole  530  of the air vent cover  53  and the air hole  510  of the gasket  51 . 
         [0031]    During the inflation, the connection ring  500  of the inflating unit  5  engages an air pin mounted through an inflatable object first. The hand grip  21  is held and pulled up and pressed down continuously. As mentioned above, when the piston rod  20  is moved upwardly, air enters the pump body  10  through the air inlet channel  14 . When the piston rod  20  is moved downwardly, air can only flow out of the pump body  10  through the air outlet channel  15  so as to inflate the inflatable object through the air pin mounted through the inflatable object and connected with the connection ring  500 . 
         [0032]    With reference to  FIG. 7 , an air inlet channel  14 A and an air outlet channel  15 A are respectively and integrally formed through the pump body  10 A. The deflating unit  4 A and the inflating unit  5 A are respectively mounted in the air inlet channel  14 A and the air outlet channl  15 A. With reference to  FIG. 8 , a through hole  12 B is integrally formed through a top end of the pump body. The piston rod  20 B is mounted through the through hole  12 B. 
         [0033]    With the check valves  40 ,  50  mounted oppositely in the air inlet channel  14  and the air outlet channel  15 , air can only flow in and out of the pump body  10  through one specific channel  14 ,  15 . When an inflatable object is connected to the air inlet channel  14  or the air outlet channel  15  of the pump body, repeatedly moving the hand grip or the piston rod  20  up and down can deflate or inflate the inflatable object. Accordingly, the dual duty hand pump provides a practical and convenient solution to integrate inflating and deflating functions as a whole. 
         [0034]    Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.