Abstract:
An air pump manually rotated to inflate and deflate an air mattress has a housing, a first and a second air vents mounted on the housing, an air valve selectively actuated to block or open the second air vent, and a mounting rack in the housing. The mounting rack is rotated so that a first or a second air compartment in the mounting rack is aligned with the second air vent, and the air valve is propped up by an undulant baffle on the mounting rack to switch to one of inflation, deflation and pressure hold-up modes. Given the structure of the air pump, the first and second air vents are flexibly arranged and can be respectively mounted on a top and a bottom of the housing and directly aligned with mutually. Therefore, the air path is shortened to make the inflation and deflation faster and more efficient.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is related to an air pump for an air mattress, and more particularly to an air pump manually operated to rapidly inflate and deflate an air mattress. 
         [0003]    2. Description of the Related Art 
         [0004]    Air pumps are critical parts of inflatable air mattresses. Usually, air pumps are mounted inside the inflatable air mattresses for inflating and deflating air mattresses and also maintaining the pressure therein. As inflatable air mattresses can be used or stored by inflating and deflating it, they are widely used for traveling and going camping or providing a temporary bed. 
         [0005]    Currently, a conventional air pump for an air mattress has a housing, and a motor, an impeller, a solenoid valve, a slider and an air valve mounted inside the housing. An air vent and an air slot are respectively mounted on a side and a bottom of the housing. The air valve seals the air vent, and the slider corresponds to the air slot. The air valve is connected to one end of the rod of the solenoid valve, and the slider is connected to the other end of the rod of the solenoid valve. When the motor drives the impeller to rotate with a high speed in generation for an air flow, the air valve is controlled by the solenoid valve to open and close the air vent. Meanwhile, the slider is driven by the solenoid valve to switch the direction for an air flow so as to inflate or deflate the air mattress. 
         [0006]    Despite the inflating and deflating features owned by the conventional air pump, there are still many problems of the conventional air pump yet to be improved, especially poorly fitting structural elements reducing efficiency and poor air flow path, specifically, the air valve and the slider are all activated by the rod of the solenoid valve. As a consequence, the air vent and the air slot are respectively mounted on the side and the bottom of the housing so the air flow path is not straight for inflation or deflation. Therefore, air must detour to flow from the bottom to the side or the other way around so increasing the length of the air flow path and the corresponding drag force, tantamount to longer time for an air flowing in the air pump and slower inflation speed of the air pump. 
       SUMMARY OF THE INVENTION 
       [0007]    An objective of the present invention is to provide an air pump for an air mattress manually operated to rapidly inflate and deflate an air mattress, and providing shorter air path inside the air pump and faster inflation and deflation speed. 
         [0008]    To achieve the foregoing objective, the air pump for an air mattress has a housing, a rotary mounting rack, a motor and an air valve. 
         [0009]    The housing has a chamber, a first air vent, a second air vent. 
         [0010]    The chamber is defined in the housing. 
         [0011]    The first air vent is mounted on a top of the housing, communicates with the chamber, and is adapted to be exposed beyond an air mattress. 
         [0012]    The second air vent is mounted on a bottom of the housing, communicates with the chamber, and is adapted to communicate with the air mattress. 
         [0013]    The rotary mounting rack is pivotally mounted in the chamber and has a first air compartment, a second air compartment, an air inlet, an air outlet, an undulant baffle, and a blocking plate. 
         [0014]    The first air compartment is mounted to one end thereof. 
         [0015]    The second air compartment communicates with the first air compartment through a first opening formed through a first partition between the first air compartment and the second air compartment, communicates with the first air vent through a second opening formed through a second partition of the second air compartment opposite to the first partition and abutting the first air vent. 
         [0016]    The air outlet is formed through a bottom of the first air compartment, and is directly aligned with the second air vent by rotating the mounting rack; 
         [0017]    The air inlet is circularly juxtaposed with the air outlet on the mounting rack with respect to a pivot axis of the mounting rack, is formed through a bottom of the second air compartment, and directly aligned with the second air vent by rotating the mounting rack. The undulant baffle is formed thereon. 
         [0018]    The blocking plate is pivotally mounted on a pivot shaft of the mounting rack, is covered on the second opening when the mounting rack is rotated and the air inlet is aligned with the second air vent, and is uncovered on the second opening when the mounting rack is rotated and the air outlet is aligned with the second air vent. The motor is mounted inside the chamber and has an impeller mounted on a spindle thereof and located in the first air compartment. 
         [0019]    The air valve is mounted at the second air vent propped up by the air flow generated by the motor and the impeller while inflating and by the undulant baffle while deflating to open the second air vent. 
         [0020]    Differing from conventional air pump for an air mattress, the present invention employs the first air compartment or the second air compartment selectively aligned with the second air vent, and the air valve propped up by the undulant baffle on the mounting rack so as to switch to different operation mode. Structurally, the present invention is more flexible in arranging the layout of the first air vent and the second air vent which can be directly aligned each other. Consequently, such layout facilitates shortening the air paths inside the air pump, rendering a fast and efficient inflation and deflation speed of the air pump for an air mattress. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view of a first preferred embodiment of an air pump for an air mattress in accordance with the present invention; 
           [0022]      FIG. 2  is an exploded perspective view in  FIG. 1 ; 
           [0023]      FIG. 3  is a cross-sectional view in  FIG. 1  when the air pump is inflating; 
           [0024]      FIG. 4  is another cross-sectional view taken along a line M-M in  FIG. 3  when the air pump is inflating; 
           [0025]      FIG. 5  is a cross-sectional view in  FIG. 1  when the air pump is maintaining pressure in the air mattress; 
           [0026]      FIG. 6  is a cross-sectional view in  FIG. 1  when the air pump is deflating; 
           [0027]      FIG. 7  is another cross-sectional view taken along a line N-N in  FIG. 6  when the air pump is deflating; 
           [0028]      FIG. 8  is an enlarged partially-exploded perspective view of the motor and the mounting rack in  FIG. 1 ; and 
           [0029]      FIG. 9  is an enlarged perspective view of the motor and the mounting rack in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    With reference to  FIGS. 1 to 9 , an air pump for an air mattress has a housing ( 10 ), a chamber ( 101 ), a first air vent ( 102 ), a second air vent ( 103 ), a mounting rack ( 30 ) and a motor ( 40 ), an air valve ( 20 ). 
         [0031]    The chamber ( 101 ) is defined inside the housing ( 10 ). The first air vent ( 102 ) is mounted on a top of the housing ( 10 ), communicates with the chamber ( 101 ), and is exposed beyond the air mattress in which the air pump is mounted. The second air vent ( 103 ) is mounted on a bottom of the housing ( 10 ) opposite to the top of the housing ( 10 ), and communicates with the chamber ( 101 ) and an inner space of the air mattress. The first air vent ( 102 ) and the second air vent ( 103 ) may be arranged to directly align to each other. The air valve ( 20 ) is mounted at the second air vent ( 103 ) to block or open the second air vent ( 103 ). The mounting rack ( 30 ) and the motor ( 40 ) are mounted inside the chamber ( 101 ) and located between the first air vent ( 102 ) and the second air vent ( 103 ). 
         [0032]    The mounting rack ( 30 ) has a grip ( 31 ), a first air compartment ( 32 ) and a second air compartment ( 33 ), a first opening ( 301 ), a second opening ( 302 ), an air outlet ( 34 ), an air inlet ( 35 ), an undulant baffle ( 36 ) and a blocking plate ( 11 ). 
         [0033]    The grip ( 31 ) is mounted on a top surface of the mounting rack ( 30 ) and extended therefrom. The first air compartment ( 32 ) communicates with the second air compartment ( 33 ) through the first opening ( 301 ) formed through a first partition ( 37 ) between the first air compartment ( 32 ) and the second air compartment ( 33 ), and both air compartments ( 32 ,  33 ) are adjoined at one end of the mounting rack ( 30 ). The second air compartment ( 33 ) communicates with the first air vent ( 102 ) through the second opening ( 302 ) formed through a second partition ( 38 ) of the second air compartment ( 33 ). The air outlet ( 34 ) is formed through a bottom side of the first air compartment ( 32 ) to align to the second air vent ( 103 ). The air inlet ( 35 ) is formed through a bottom side of the second air compartment ( 33 ) to align to the second air vent ( 103 ). The air inlet ( 35 ) and the air outlet ( 34 ) are juxtaposed on a circle centered at a pivot axis of a pivot shaft of the mounting rack ( 30 ). The undulant baffle ( 36 ) is formed on the mounting rack ( 30 ) to constantly contact with the air valve ( 20 ). The undulant baffle is preferred to take a form of having two wave crests and one wave trough. The blocking plate ( 11 ) is pivotally mounted on the pivot shaft of the mounting rack ( 30 ). When the mounting rack ( 30 ) is rotated and the air inlet ( 35 ) communicates with the second air vent ( 103 ), the blocking plate ( 11 ) is covered on the second opening ( 302 ) to prevent air from leaking from the second opening. When the mounting rack ( 30 ) is rotated and the air outlet ( 34 ) communicates with the second air vent ( 103 ), the second opening is not covered by the blocking plate ( 11 ), thereby facilitating air flowing into the second air compartment ( 33 ) through the second opening ( 302 ) and forming a gust of intake air flow. 
         [0034]    The motor ( 40 ) is fixedly mounted at the other end of mounting rack ( 30 ), is located inside the mounting rack ( 30 ), and is synchronously rotated with the mounting rack ( 30 ) when the mounting rack ( 30 ) is rotated. The motor ( 40 ) has an impeller ( 41 ) mounted on a spindle of the motor ( 40 ) and located inside the first air compartment ( 32 ). 
         [0035]    The air valve ( 20 ) has a yoke ( 21 ), a spring ( 22 ) and a rubber plate ( 23 ). The yoke ( 21 ) has a seat ring ( 211 ) and a stem ( 212 ). The seat ring ( 211 ) has a plurality of arms radially connected with a center and a rim thereof. The stem ( 212 ) is perpendicularly extended from the center of the seat ring ( 211 ). The rubber plate ( 23 ) is fixedly mounted to the seat ring ( 211 ) and accompanies with the seat ring ( 211 ) to hermetically seal the second air vent ( 103 ). A tail end of the stem ( 212 ) penetrates through a positioning hole defined at the second air vent ( 103 ) to prop up a bottom surface ( 414 ) of the sloping partition ( 413 ). The spring ( 22 ) is sleeved around the stem ( 212 ). One end of the spring ( 22 ) is urged against the tail end of the stem ( 212 ) and the other end is urged against an inner surface of the housing ( 10 ) so that the yoke ( 21 ) and the rubber plate ( 23 ) as a whole can elastically seal or open the second air vent ( 103 ). 
         [0036]    With further reference to  FIGS. 3 to 7 , operation of the present invention is described as follows. 
         [0037]    The air pump of the present invention has three types of operating modes, namely, inflation, pressure hold-up and deflation. 
         [0038]    During the inflation mode, air outside the air mattress is promptly pumped into an inner chamber of the air mattress to inflate the air mattress until it is ready for use. Upon inflating, the grip ( 31 ) on the mounting rack ( 30 ) is shifted to rotate the mounting rack ( 30 ) with respect to the axis of the pivot shaft of the mounting rack ( 30 ) so as to let the air outlet ( 34 ) directly communicate with the second air vent ( 103 ). Then, the motor ( 31 ) drives the impeller ( 32 ) to rotate with a high speed and generates a gust of intake air flow, and the air valve ( 20 ) is either pushed by the gust of intake air flow or propped up by the undulant baffle ( 36 ) to open the second air vent ( 103 ). Air outside the air mattress sequentially flows through the first air vent ( 102 ), the second opening ( 302 ), the second air compartment ( 33 ), the first opening ( 301 ), the first air compartment ( 32 ), the air outlet ( 34 ) and the second air vent ( 103 ) to the inner chamber as marked by arrowheads in  FIGS. 3 and 4 , to fulfill the function of inflation. 
         [0039]    During the pressure hold-up mode, the air mattress is fully inflated and the motor ( 40 ) is switched off by shifting the grip ( 31 ) as shown in  FIG. 5 . At the time, since the air pressure in the inner chamber of the air mattress is far higher than the atmospheric pressure outside the air mattress, the air valve ( 20 ) tightly seals the second air vent ( 103 ) due to the pressure difference effect, achieving the pressure holding function. 
         [0040]    During the deflation mode, air inside the inner chamber of the air mattress is evacuated. When the air mattress is no longer in use and needs to be packed up and deflated, the grip ( 31 ) on the mounting rack ( 30 ) is shifted to rotate the mounting rack ( 30 ) with respect to the pivot axis of the mounting rack ( 30 ) so as to let the air inlet ( 35 ) communicate with the second air vent ( 103 ). Meanwhile, the air valve is propped up by the undulant baffle ( 36 ) to open the second air vent ( 103 ), and the motor ( 31 ) drives the impeller ( 32 ) to rotate with a high speed and generates a gust of exhaust air flow. After sequentially flowing through the second air vent ( 103 ), the air inlet ( 35 ), the second air compartment ( 33 ), the first opening ( 301 ), the first air compartment ( 32 ), the air outlet ( 34 ) and the first air vent ( 102 ) (as marked by arrowheads in  FIGS. 6 and 7 ), air inside the air mattress is evacuated to fulfill the function of deflation. Besides, air flowing along the air path inside the air pump also carries away the heat generated by the motor ( 40 ). 
         [0041]    In sum, the present invention is characterized in that the first and second air compartments are alternately aligned with communicate with the second air vent by rotating the mounting rack, and the air valve is propped up by the undulant baffle on the mounting rack, so as to switch the operating modes of the air pump. In contrast to conventional air pumps using the rod of the solenoid valve to simultaneously drive the slider and the air valve, the arrangement of the first air vent and the second air vent in the present invention is more flexible. Given the flexible arrangement, the first air vent and the second air vent can be respectively mounted on a top surface and a bottom surface of the housing. As such, the air path inside the air pump is shortened to result in a direct and fast inflation and deflation of the air mattress. 
         [0042]    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.