Abstract:
The disclosure is of a medical valve for handling oxygen and suction and including a suction flow path in which there is a means for throttling down the flow to a level at which there are no, possibly damaging, surges.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to apparatus for treating a medical patient with oxygen or suction or both. Some apparatus is known for feeding oxygen or suction or both to a patient but none is known in which the pressure of gas can be controlled and the patient can be so well protected from a surge of pressure. 
     SUMMARY OF THE INVENTION 
     The present invention can be used to feed gases while maintaining tight control on gas pressure surges to which the patient might be subjected. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The drawing is a sectional view through the control valve of the invention. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to the drawing, the control valve of the invention  10  includes a generally cylindrical housing  20  of metal, plastic or the like suitable for the purposes of the invention. The housing includes a piston  30  of metal or other suitable material slidably disposed therein. The housing includes a cap  40  at its upper end and a cap  60  at its lower end The upper cap is slidable up and down on the upper end of the housing. 
     The piston carries, near its upper end, an assembly of plates  70  spaced apart by an O-ring  74 . This assembly slides inside the cylinder in gas-tight engagement with the inner wall of the housing cylinder. In the up position of the plunger, the The assembly of plates  70  engages the upper end wall of the cylinder as a stop. The upper cap is slidable on the housing. 
     The piston also carries an assembly of plates  80  and O-ring  84  positioned as described below. 
     The housing  20  carries the following tubes. An oxygen tube  100  is secured to the housing near the upper end thereof below the assembly of plates  70  (when the plunger is up) and this tube is connected to a source of oxygen at a wall mounting. Beneath this tube is a patient tube  110  which extends by a catheter  120  to a patient. Finally, a suction tube  130  is secured near the lower end of the housing beneath the patient tube and extends to a source of suction at the wall. The lower set of plates  80  is positioned just above the suction tube  130  when the plunger is up. 
     As seen in the drawing, the piston is in the up position in which the tube  100  from wall oxygen has oxygen flow from the wall around the piston to the outlet  100  to the patient. At this time, the lower assembly of plates causes suction to flow to atmosphere through the slits in the lower cap. If the cap is pressed downwardly, the piston moves to the position in which the oxygen tube  100  is blocked by the plate assembly  70  and the outlet to the patient is open and the lower plates are beneath the suction line  130  as shown in dash lines. Thus there can be flow of suction from the wall to the patient. 
     According the invention, the outer wall of the piston is provided with an enlargement  150  which is called a throttle plate. This enlargement is of such size that when the plunger is down, the throttle plate lies in the path from the patient to the source of suction. The throttle plate does not block this path but throttles down the velocity of the flow of suction where surges are prevented. 
     In operation of the valve  10 , when the piston is raised, oxygen flows from the wall into tube  190  and through the piston and out the tube to a patient. At this time, the assembly of plates  150  blocks a suction path and causes suction to flow to atmosphere through the slots in the bottom cap  170 . 
     When the plunger is pushed down, the plate  150  lies below the suction line and the throttle lies across the opening in the tube and air flow from the wall suction source in the patient tube is reduced in velocity or intensity and controlled suction is achieved. This prevents suction surges and provide safety for the patient.