Patent ID: RE40669

Claim:
A fluid pump comprising: an elastic bladder, at least a portion of the interior surface area of said bladder being changeable between a contracted state have having a first surface area and an expanded state having a second surface area that is substantially greater than said first surface area, said bladder having a fluid inlet and a fluid outlet; means for causing substantially one-way fluid flow through said bladder; a housing around at least a portion of said bladder, an annular a volume being defined in the space between said housing and said bladder, said annular volume being occupied by a driving fluid; means for changing the pressure of said driving fluid in said annular volume to alternately expand and contract said bladder to change the interior surface area and volume of said bladder; and a driving fluid flow regulating means in said annular volume space between said bladder and said housing for expanding and contracting selected areas of said bladder adapted, in a filling phase, to expand a selected area of said bladder adjacent said inlet and thereafter progressively expand the remaining areas of said bladder towards said bladder outlet substantially in the direction of fluid flow , and during an ejection phase, to initially contract said bladder adjacent said bladder inlet and thereafter progressively contract the remaining areas of the bladder towards said bladder outlet said bladder substantially in the direction of fluid flow .