Patent ID: 6158972
Filing Date: 2000-12-12
Classification: F04B

Abstract:
A fluid actuated fuel pump assembly comprising;a body (12) defining separate concave inlet (14) and outlet (16) hollows,a first pulse cover (18) disposed over said inlet hollow (14),a first flexible diaphragm (20) sandwiched between said first pulse cover (18) and said body (12) to define a first pulse chamber (22) with said first pulse cover (18) and a first pumping chamber (24) with said inlet hollow (14),said body (12) defining a fuel intake passage (48) for admitting fuel into said first pumping chamber (24) as said first diaphragm (20) moves away from and toward said inlet hollow (14) to vary the volume of said first pumping chamber (24),a second pulse cover (26) disposed over said outlet hollow (16),a second flexible diaphragm (28) sandwiched between said second pulse cover (26) and said body (12) to define a second pumping chamber (30) with said outlet hollow (16) and a second pulse chamber (32) with said second pulse cover (26),said body (12) defining a fuel outlet passage (50) for conveying full from said second pumping chamber (30) as said second diaphragm (28) moves away from and toward said outlet hollow (16) to vary the volume of said second pumping chamber (30),said first pulse cover (18) including a first pressure inlet (42) communicating with said first pulse chamber (22) and adapted for connection to a first source of regularly cycling pressure pulses to move said first diaphragm (20),said second pulse cover (26) including a second pressure inlet (44) communicating with said second pulse chamber (32) and adapted for connection to a source of regularly cycling pressure pulses to move said second diaphragm (28),a fuel transfer valve (88) through which fulel is pumped from said first pumping chamber (24) to said second pumping chamber (30) in response to said first diaphragm (20) being moved toward said inlet hollow (14),including first biasing means (78) for biasing said first diaphragm (20) in a direction away from said inlet hollow (14), and second biasing means (80) for biasing said second diaphragm (28) in a direction toward said outlet hollow (16),said first (78) and second (80) biasing means and said transfer valve (88) being axially aligned.