Air displacement apparatus for use with a fluid transfer device

A liquid sealed air displacement apparatus comprising:

• a linear actuator;
• a floating coupling coupled to said linear actuator;
• a piston coupled to said floating coupling;
• a cylinder defining a displacement chamber for receiving said piston, wherein said piston causes displacement of air when said piston retracts from said displacement chamber in said cylinder, said piston and said cylinder defining a diametrical clearance configured to receive a sealing fluid, wherein said diametrical clearance is configured with a dimension to substantially maintain said sealing fluid between said piston and said cylinder;
• a compression spring configured to bias said piston away from said cylinder;
• a port fitting connector coupled to an end of said cylinder;
• and
• a housing holding at least said linear actuator, said piston, said cylinder, said floating coupling, and said compression spring.

A fluid transfer device comprising:

• a piston configured to be coupled to a linear actuator;
• a cylinder defining a displacement chamber for receiving said piston, wherein said piston causes displacement of air when said piston retracts from said displacement chamber in said cylinder, said piston and said cylinder defining a diametrical clearance configured to receive a sealing fluid, wherein said diametrical clearance is configured with a dimension to substantially maintain said sealing fluid between said piston and said cylinder;
• a sealing fluid received in said diametrical clearance between said piston and said cylinder, wherein said sealing fluid substantially prevents air leakage into said displacement chamber;
• and
• a fluid receiving member coupled to an end of said cylinder, wherein said fluid receiving member includes a fluid passage in communication with said air displacement chamber such that retraction of said piston creates suction in said displacement chamber causing a fluid to be drawn into said fluid passage.

A liquid sealed air displacement apparatus comprising:

• a piston configured to be coupled to a linear actuator;
• a cylinder defining a displacement chamber for receiving said piston with a diametrical clearance between said piston and said cylinder, wherein said piston causes displacement of air when said piston retracts from said displacement chamber in said cylinder, said cylinder including an inner wall defining an annular groove configured to receive a sealing fluid, wherein said diametrical clearance and said annular groove are configured with a dimension to substantially maintain said sealing fluid between said piston and said cylinder;
• and
• a sealing fluid received in said diametrical clearance and said annular groove between said piston and said cylinder, wherein said sealing fluid substantially prevents air leakage into said displacement chamber.