Abstract:
A control valve structure for an oxygen machine uses a motor to link a disc to spin, which activates a pair of valve rods to open and close in sequence through rotation of the motor to control air flow.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a control valve structure for an oxygen machine, and more particularly to a pair of valve rods activated by a disc of a motor to control air passages. 
   2. Description of the Prior Art 
   A conventional oxygen maker on the market uses an air compressor to suck air and to filter the air in the compressor before providing it to a user. The basic design is to suck air from outside into the compressor, and then filter the air to produce oxygen. 
   U.S. Pat. No. 6,062,260 discloses a pair of electromagnetic valves of an air inlet control valve to control two pistons in the control valve to move in sequence so that air flows in and out in a circle status. 
   However, should any of the electromagnetic valves is not functioning, the air flow in sequence is broken and air flow is out of control, thus oxygen can not be produced properly. 
   SUMMARY OF THE INVENTION 
   It is the primary object of the present invention to provide a control valve structure for an oxygen machine, which uses a motor to link a cam on a disc to rotate and controls two valve rods to move in a reciprocating movement. The design is simple and easy to operate. 
   It is another object of the present invention to provide a control valve structure for an oxygen machine, which operation can be controlled accurately. 
   It is a further object of the present invention to provide a control valve structure for an oxygen machine, which is easy to maintain. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of the present invention; 
       FIG. 2  is a perspective view of an air valve of the present invention 
       FIG. 3  is a cross-sectional view of the present invention; 
       FIG. 4  is a cross-sectional view taken along line A-A of  FIG. 3 ; 
       FIG. 5  is a cross-sectional view taken along line B-B of  FIG. 3 ; and 
       FIG. 6  is a cross-sectional view showing operation of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As shown in  FIG. 1 , the present invention comprises a valve seat  1 , a motor  2 , a disc  3 , an air valve  4 , a pair of first and second valve rods  5  and  5 A, a pair of first and second valve rod seats  6  and  6 A, a washer  7  and an air filter  8 . 
   The valve seat  1  has a through hole  11  for a spindle  21  of the motor  2  to insert there through. The spindle  21  has a cut-off section at the front end. The valve seat  1  is provided with three pulleys  12  spaced from one another for the disc  3  to secure thereat. 
   The disc  3  has one side leaning on the pulleys  12  of the valve seat  1 , while the other side of the disc  3  is formed with a half cam  31  having a first slanting surface  311  and a second slanting surface  312  on respective ends thereof, and a hole  32  at the center with a cut-off section corresponding to the cut-off section of the spindle  21 . 
   The air valve  4 , as shown in  FIG. 2 , corresponds in shape to the valve seat  1  and comprises a first air chamber  41 , a pair of second air chambers  42  and  42 A, and a third air chamber  43 . All of the air chambers are formed longitudinally thereon and separated from one another, and are surrounded with a trough  44 . The air valve  4  further comprises an air inlet  45  interconnected with the first air chamber  41 , and a first air hole  46  and a second air hole  47  transversally interconnected with the first air chamber  41 , the second air chambers  42  and the third air chamber  43 , respectively, to receive the first valve rod  5  and the second valve rod  5 A therein. 
   Both the first valve rod  5  and the second valve rod  5 A are sleeved with springs  51  and  51 A, sealing rings  52  and  52 A. One end of each of the valve rods  52  and  52 A is provided with a pulley  53  and  53 A, respectively, while the other end of which is formed with holes  54  and  54 A, respectively. 
   Both the first valve rod seat  6  and the second valve rod seat  6 A comprise a circular holders  61  and  61 A with a barrel holders  62  and  62 A therein, respectively, as shown in  FIG. 3 . The holders  61  and  61 A comprise notches  63  and  63 A at the bottom ends which are interconnected with the holders  61  and  61 A. 
   The washer  7  is shaped to fit the trough  44  surrounding the first air chamber  41 , the second air chambers  42  and  42 A, and the third air chamber  43 . 
   The air filter  8  comprises a pair of particle filters  81  and  82  and a base plate  83 . The base plate  83  comprises a pair of holes  831  and  832  interconnected with the particle filters  81  and  82 , respectively, and an exhausting chamber  833  having an exhausting hole  834  therein. 
   To install the present invention, as shown in  FIGS. 3 ,  4 , and  5 , the spindle  21  of the motor  2  is inserted through the through hole  11  of the valve seat  1  and the hole  32  of the disc  3 . Whereas the disc  3  has one side engaging with the pulleys  12  of the valve seat  1 , when the motor  2  is activated, the pulleys  12  link the disc  3  to spin on the valve seat  1 . The first valve rod  5  and the second valve rod  5 A are inserted into the first valve rod seat  6  and the second valve rod seat  6 A, and then inserted into the first air hole  46  and the second air hole  47 , respectively, and stay at the intersections between the first valve rod seat  6  and the second valve rod seat  6 A, the first air chamber  41 , the second air chambers  42  and  42 A, and the third air chamber  43 . The springs  51  and  51 A sleeved on the first valve rod  5  and the second valve rod  5 A are engaged with the bottom ends of the first air hole  46  and the second air hole  47 , respectively. Upon the air valve  4  is secured with the valve seat  1 , the pulleys  53  and  53 A at the other ends of the first valve rod  5  and the second valve rod  5 A are engaged with the disc  3 . 
   The air valve  4  with the washer  7  and the valve seat  1  are secured to the base plate  83  of the air filter  8 . The holes  831  and  832  of the base plate  8  are interconnected with the second air chambers  42  and  42 A, while the exhausting chamber  833  is interconnected with the third air chamber  43 . 
   To practice the present invention, as shown in  FIGS. 3 through 5 , the spindle  21  of the motor  2  links the disc  3  to spin by means of the pulleys  12  of the valve seat  1 . Whereas the cam  31  of the disc  3  spins with respect to the first valve rod  5  and the second valve rod  5 A, the pulleys  53  and  53 A of the first valve rod  5  and the second valve rod  5 A move along the first slanting surface  311  and the second slanting surface  312  of the cam  31  in a reciprocating movement to control the passages of the first air chamber  41 , the second air chambers  42  and  42 A, and the third air chamber  43 , respectively. 
   For example, as shown in  FIG. 3 , when the cam  31  of the disc  3  is spinning with respect to the second valve rod  5 A, the first slanting surface  311  of the cam  31  engages with the pulley  53 A of the second valve rod  5 A, so that when the valve rod  5 A spins with the disc  3 , the spring  51 A is pressed and the second valve rod  5 A moves in the second air hole  47 , while the sealing ring  52 A of the second valve rod  5 A blocks the intersection between the second air hole  47  and the first air chamber  41 , therefore, air from the air inlet  45  is blocked from entering into the second air chamber  42 A. The exhausting air from the particle filter  82  flows through the second air chamber  42 A and the second air hole  47  to the holder  61 A of the second valve rod seat  6 A, and expels from the notch  63 A of the holder  61 A to the third air chamber  43 , due to the intersection between the third air chamber  43  and the exhausting chamber  833 , the exhausting air then goes through the exhausting hole  834  of the exhausting chamber  833  of the base plate  83 . 
   In the movement described above, as shown in  FIG. 5 , the first valve rod  5  is not activated by the cam  31  of the disc  3 , so that the sealing ring  52  is not engaged with the first air chamber  41  interconnected with the air inlet  45 , and stays contact with the holder  61  of the first valve rod seat  6 . Thus air is blocked from entering the holder  61  of the first valve rod seat  6 . The air from the first air chamber  41  goes through the holes  54  of the first valve rod  5 , the first air hole  46 , the second air chamber  42 , and the hole  831  of the base plate  83  into the particle filter  82 . 
   On the contrary, as shown in  FIG. 6 , the first valve rod  5  is activated while the second valve rod  5 A is deactivated. (The air flows in an opposite direction from the aforesaid, therefore, it will not be described hereinafter.) The air in the first air chamber  41  will flow through the second air hole  47  and into the second air chamber  42 A and the particle filter  82 . The exhausting air from the particle filter  81  will flow through the second air chamber  42 , the notch  63  of the first valve rod seat  6  in the first air hole  46  into the third air chamber  43 , and then is expelled through the exhausting hole  834  of the exhausting chamber  833  on the base plate  83 . 
   In the present invention, the motor  2  links the cam  31  of the disc  3  to spin, which maintains the first valve rod  5  and the second valve rod  5 A in the air valve  4  to be activated in turn.