Abstract: A housing having a motor mounted therein with the shaft thereof projecting through an opening in one sidewall of the housing. A partially cylindrical wall is mounted upon the sidewall substantially concentric with the rotational axis of the motor, and a rotor is eccentrically mounted upon the shaft for rotation relative thereto. A resiliently flexible tube is disposed between the rotor and the wall, whereby to produce what is called a peristaltic type of pumping action with each rotation of the shaft. Thus, a liquid disposed within the tube is urged intermittently to move through the tube in a pulsating manner. One end of the tube is connected to a source of liquid and the other end is connected to a nozzle having a manually-operable flow control device thereon.