for compressing and discharging fluid within a container the apparatus includes an oscillating rotor or cam like projection of substantially constant thickness in the plane of the longitudinal axis of the housing which cooperates with a sliding partition to define multiple compartments into which fluid is introduced during a portion of the rotation of the rotor or projection and is compressed during another portion of rotation of the rotor or projection application_number US 63903775 A description with continued reference to the drawings a housing 10 is provided having a central compartment 11 with a generally cylindrical bore and a pair of end compartments 12 and 13 arranged along a common axis the central compartment is separated from the end compartments by parallel inner walls 14 and 15 which extend entirely across the bore of the housing 10 and normal to the axis thereof the end compartments 12 and 13 are provided with end walls 16 and 17 respectively each of which is provided with an inwardly extending boss 18 having a bearing or bushing 19 disposed generally axially of the compartments a drive shaft 20 is rotatably supported by the bearing 19 and such shaft is adapted to be driven in any desired manner as by a power plant not shown an elongated hub 24 is fixed to the shaft 20 within the housing 10 and the opposite ends of such hub.