Variable Fluid Flow Rate Control Device

Abstract

A flow selector having features for controlling the flow rate of a fluid over a continuous range of flow rates is provided. In particular, a flow selector including a flow rate selection mechanism is provided, where the flow rate selection mechanism provides more precise control of the fluid flow rate. A flow selector comprising a needle valve for controlling the flow rate of a fluid over a continuous range of flow rates also is provided.

We claim: 
     
         1 . A flow selector for selectively controlling a flow rate of a fluid, the flow selector comprising:
 an inlet tube;   an outlet tube;   a flow rate selection mechanism, the flow rate selection mechanism including
 a shaft having a distal end and a proximal end, and 
 a seat that receives the distal end of the shaft, 
   wherein the flow rate selection mechanism is positioned between the inlet tube and the outlet tube to permit an ingress of fluid from the inlet tube and an egress of fluid to the outlet tube, and   an enclosure for holding the inlet tube, the outlet tube, and the flow rate selection mechanism in position relative to each other, the enclosure having   an inlet opening for receiving the inlet tube,   an outlet opening for receiving the outlet tube, and   a shaft opening for receiving the shaft of the flow rate selection mechanism.   
     
     
         2 . The flow selector of  claim 1 , wherein the shaft of the flow rate selection mechanism comprises indicia for indicating a selected flow rate to a user of the flow selector. 
     
     
         3 . The flow selector of  claim 2 , wherein the indicia comprise a series of numbers representing a range of flow rates selectable using the flow selector. 
     
     
         4 . The flow selector of  claim 1 , wherein the enclosure comprises a first side and a second side, the second side being opposite the first side, and wherein the first side defines the inlet opening and the shaft opening and the second side defines the outlet opening. 
     
     
         5 . The flow selector of  claim 1 , wherein the enclosure comprises a first side and a second side, the second side being opposite the first side, and wherein the first side defines the inlet opening and the second side defines the outlet opening and the shaft opening. 
     
     
         6 . The flow selector of  claim 1 , wherein the enclosure comprises a first side and a second side, the second side being opposite the first side, and wherein the first side defines the inlet opening and the outlet opening and the second side defines the shaft opening. 
     
     
         7 . The flow selector of  claim 1 , wherein the enclosure comprises a first side, a second side, and a third side, the second side being opposite the first side and the third side being between the first side and the second side, and wherein the first side defines the inlet opening, the second side defines the outlet opening, and the third side defines the shaft opening. 
     
     
         8 . The flow selector of  claim 1 , wherein the distal end of the shaft and the seat of the flow rate selection mechanism are positioned within the enclosure and the proximal end of the shaft of the flow rate selection mechanism is positioned outside the enclosure. 
     
     
         9 . The flow selector of  claim 1 , wherein the proximal end of the shaft comprises a control knob. 
     
     
         10 . The flow selector of  claim 1 , wherein the flow rate selection mechanism is a needle valve. 
     
     
         11 . A flow selector for selectively controlling a flow rate of a fluid, the flow selector comprising:
 an inlet tube;   an outlet tube;   a needle valve, the needle valve including
 a shaft having a distal end and a proximal end, and 
 a seat that receives the distal end of the shaft, 
 wherein the distal end of the shaft is tapered in shape and the seat has a recess with a shape complementary to the shape of the distal end of the shaft, and 
   an enclosure for holding the inlet tube, the outlet tube, and the needle valve in position relative to each other, the enclosure having
 an inlet opening for receiving the inlet tube, 
 an outlet opening for receiving the outlet tube, and 
 a shaft opening for receiving the shaft of the needle valve, 
 wherein the distal end of the needle valve is positioned between the inlet tube and the outlet tube within the enclosure to permit an ingress of fluid from the inlet tube and an egress of fluid to the outlet tube. 
   
     
     
         12 . The flow selector of  claim 11 , wherein the shaft of the needle valve comprises indicia for indicating a selected flow rate to a user of the flow selector. 
     
     
         13 . The flow selector of  claim 12 , wherein the indicia comprise a series of numbers representing a range of flow rates selectable using the flow selector. 
     
     
         14 . The flow selector of  claim 11 , wherein the distal end of the shaft is received within the recess of the seat, and wherein the distal end of the shaft is configured to move along an axial direction within the recess to adjust a flow rate of fluid through the needle valve. 
     
     
         15 . The flow selector of  claim 11 , wherein the shaft of the needle valve comprises a control knob for manual control of the flow rate of the fluid by a user of the flow selector. 
     
     
         16 . The flow selector of  claim 11 , wherein the enclosure comprises a first side and a second side, the second side being opposite the first side, and wherein the first side defines the inlet opening and the shaft opening and the second side defines the outlet opening. 
     
     
         17 . The flow selector of  claim 11 , wherein the enclosure comprises a first side and a second side, the second side being opposite the first side, and wherein the first side defines the inlet opening and the second side defines the outlet opening and the shaft opening. 
     
     
         18 . The flow selector of  claim 11 , wherein the enclosure comprises a first side and a second side, the second side being opposite the first side, and wherein the first side defines the inlet opening and the outlet opening and the second side defines the shaft opening. 
     
     
         19 . The flow selector of  claim 11 , wherein the enclosure comprises a first side, a second side, and a third side, the second side being opposite the first side and the third side being between the first side and the second side, and wherein the first side defines the inlet opening, the second side defines the outlet opening, and the third side defines the shaft opening.