Patent attributes
A rotary pump for fluids comprising a shaft to rotate about a longitudinal axis and a cylindrical rotor centrally secured to that shaft. A housing encasing the shaft and rotor includes, interior end walls adjacent to the rotor disks and an interior side wall. Fluid inlet and outlet ports are provided at spaced locations in the housing side wall. Paddles are pivotably secured to the rotor in pockets in the rotor, to pivot about points at rearward sides of the paddles, for movement between extended positions with the paddles extending outwardly beyond the cylindrical surface of the rotor and retracted positions where the paddles are seated entirely within their corresponding pockets. A means is provided to bias each paddle towards the extended position, but to allow the paddle to move towards that extended position, but to allow the paddle to move towards the retracted position.