Pneumatically-operated fluid pump with amplified fluid pressure, and related methods

Abstract

A fluid pump for pumping a subject fluid. The fluid pump including, a pump body, a first cavity within the pump body, a second cavity within the pump body, a flexible member, an incompressible fluid, a subject fluid chamber, and a piston. Piston may include a piston head and an elongated piston shaft. The piston may be configured to amplify a first pressure experienced on a first side of the piston head and exerted by a pressurized drive fluid to a second pressure experienced on an end surface of the elongated piston shaft and exerted on the incompressible fluid within the flexible member. The subject fluid may in turn be pressurized to a third pressure substantially equal to the second pressure.

What is claimed is: 
     
         1 . A fluid pump for pumping a subject fluid, the fluid pump comprising:
 a pump body;   a first cavity within the pump body;   a second cavity within the pump body;   a piston shaft hole extending from the first cavity to the second cavity;   a flexible member disposed within the second cavity, the flexible member comprising a tubular body having a first closed end and a second open end opposite the first closed end, the second open end being proximate the piston shaft hole, the flexible member configured to extend and retract within the second cavity during operation of the fluid pump;   an incompressible fluid chamber defined within the second cavity on a first side of the flexible member;   an incompressible fluid disposed within the incompressible fluid chamber;   a subject fluid chamber defined within the second cavity on a second side of the flexible member, the flexible member configured to increase and decrease a volume of the subject fluid chamber; and   a piston comprising:
 a piston head having a first side and an opposite second side, the first side of the piston head having a first surface area, the piston head movable within the first cavity; and 
 an elongated piston shaft extending from the second side of the piston head and at least partially into the piston shaft hole, wherein the elongated piston shaft has an end surface opposite the piston head, the end surface having a second surface area smaller than the first surface area of the first side of the piston head. 
   
     
     
         2 . The fluid pump of  claim 1 , wherein the piston is configured to amplify a first pressure experienced on the first surface area of the first side of the piston head to a second pressure experienced by the second surface area of the end surface of the elongated piston shaft. 
     
     
         3 . The fluid pump of  claim 2 , wherein the elongated piston shaft of the piston is configured to pressurize the incompressible fluid to a third pressure substantially equal to the second pressure experienced by the second surface area of the end surface of the elongated piston shaft. 
     
     
         4 . The fluid pump of  claim 3 , wherein the flexible member is configured to pressurize the subject fluid disposed within the subject fluid chamber to a fourth pressure substantially equal to the third pressure of the incompressible fluid. 
     
     
         5 . The fluid pump of  claim 4 , wherein a ratio of the first pressure experienced on the first surface area of the first side of the piston head and the fourth pressure of the subject fluid is at least more than 1. 
     
     
         6 . The fluid pump of  claim 4 , wherein a ratio of the first pressure experienced on the first surface area of the first side of the piston head and the fourth pressure of the subject fluid is at least 3. 
     
     
         7 . The fluid pump of  claim 4 , wherein a ratio of the first pressure experienced on the first surface area of the first side of the piston head and the fourth pressure of the subject fluid is at least 6. 
     
     
         8 . The fluid pump of  claim 1 , further comprising:
 a first drive fluid chamber located between the first side of the piston head of the piston and a first cavity interior surface of the first cavity; and   a second drive fluid chamber located between the second side of the piston head of the piston and the first cavity interior surface of the first cavity.   
     
     
         9 . The fluid pump of  claim 8 , further comprising:
 a first drive fluid inlet extending through the pump body to the first drive fluid chamber;   a second drive fluid inlet extending through the pump body to the second drive fluid chamber;   a subject fluid inlet extending through the pump body to the subject fluid chamber; and   a subject fluid outlet extending through the pump body to the subject fluid chamber.   
     
     
         10 . A pump body for pumping a subject fluid, the pump body comprising:
 a flexible member disposed within the pump body, the flexible member comprising a tubular body having a first closed end and a second open end opposite the first closed end, the flexible member containing an incompressible fluid; and   a piston comprising:
 a piston head having a first side and an opposite second side; and 
 an elongated piston shaft extending from the second side of the piston head, the elongated piston shaft having an end surface on a distal end of the elongated piston shaft opposite the piston head, and wherein the piston is configured such that a ratio of a first pressure experienced by the first side of the piston head and a second pressure experienced by the end surface of the elongated piston shaft is at least more than 1. 
   
     
     
         11 . The pump body of  claim 10 , wherein a first surface area of the first side of the piston head is larger than a second surface area of the end surface of the elongated piston shaft. 
     
     
         12 . The pump body of  claim 10 , wherein the ratio of the first pressure experienced by the first side of the piston head and the second pressure experienced by the end surface of the elongated piston shaft is at least 3. 
     
     
         13 . The pump body of  claim 10 , wherein the ratio of the first pressure experienced by the first side of the piston head and the second pressure experienced by the end surface of the elongated piston shaft is at least 6. 
     
     
         14 . The pump body of  claim 10 , wherein a fourth pressure experienced by the subject fluid is at least substantially equal to third pressure experienced by the incompressible fluid, and wherein the third pressure is at least substantially equal to the second pressure experienced by the end surface of the elongated piston shaft. 
     
     
         15 . A method of pressurizing and pumping a subject fluid, the method comprising:
 inputting a pressurized drive fluid into a first drive fluid chamber of a first cavity of a pump body, wherein the pressurized drive fluid is input on a first side of a piston head of a piston, the pressurized drive fluid exerting a first pressure on the first side of the piston head;   moving the piston along an axial length of the first cavity of the pump body;   exerting a second pressure on an incompressible fluid within an interior of a flexible member, wherein the second pressure is exerted on the incompressible fluid with an end surface of an elongated piston shaft extending from a second side of the piston head of the piston;   pressurizing the incompressible fluid to a third pressure higher than the first pressure with the elongated piston shaft of the piston and substantially equal to the second pressure;   pressurizing the subject fluid within a subject fluid chamber that least partially surrounds the flexible member to a fourth pressure higher than the first pressure and at least substantially equal to the third pressure.   
     
     
         16 . The method of  claim 15 , further comprising:
 extending the flexible member;   decreasing a volume of the subject fluid chamber in the pump body; and   dispensing at least some of the subject fluid out of the subject fluid chamber through a subject fluid outlet in the pump body.   
     
     
         17 . The method of  claim 16 , further comprising:
 inputting the pressurized drive fluid into a second drive fluid chamber of the first cavity of the pump body, wherein the pressurized drive fluid is input on the second side of the piston head of the piston;   pulling at least some of the incompressible fluid out of the interior of the flexible member with the elongated piston shaft of the piston;   retracting the flexible member;   increasing the volume of the subject fluid chamber; and   drawing at least some subject fluid into the subject fluid chamber through a subject fluid inlet in the pump body.   
     
     
         18 . The method of  claim 15 , wherein pressurizing the subject fluid to a fourth pressure comprises pressurizing the subject fluid to the fourth pressure that is at least 2 times the first pressure experienced by the first side of the piston head. 
     
     
         19 . The method of  claim 15 , wherein pressurizing the subject fluid to a fourth pressure comprises pressurizing the subject fluid to the fourth pressure that is at least 4 times the first pressure experienced by the first side of the piston head. 
     
     
         20 . The method of  claim 15 , wherein pressurizing the subject fluid to a fourth pressure comprises pressurizing the subject fluid to the fourth pressure that is at least 6 times the first pressure experienced by the first side of the piston head.