Patent ID: 7144228

Claim:
A cryogenic fluid delivery system comprising: a. a storage tank containing a supply of cryogenic liquid; b. a pump including: i) a pumping cylinder having an inlet in communication with said storage tank, an outlet and a pumping piston slidingly positioned therein so that cryogenic liquid from the storage tank is pumped through the pumping cylinder outlet by motion of the pumping piston; ii) an actuating cylinder having an inlet, an outlet and an actuating piston slidingly positioned therein; iii) a supplemental linear actuator; iv) said supplemental linear actuator, actuating piston and pumping piston joined by at least one connecting rod so that the pumping piston is driven by the actuating piston and the supplemental linear actuator; c. a heat exchanger in circuit between the pumping cylinder outlet and the actuating cylinder inlet, said heat exchanger vaporizing a-portion of the pumped cryogenic liquid so that said actuating piston is propelled by the resulting cryogenic vapor; and d. a liquid delivery line also in communication with the pumping cylinder outlet so that a portion of the pumped cryogenic liquid may be delivered therethrough.