Patent ID: 6872059
Filing Date: 2005-03-29
Classification: F04B

Abstract:
1. A liquid discharger including a base for placing a resilient tube thereat, the liquid discharger comprising: at least two balls that roll on the tube while pressing and squashing separate portions of the tube; a retainer movable along the tube, said retainer having ball holding sections for holding said balls as the balls rotate along the tube; a driving mechanism for rolling the balls; a tube guide groove formed in the base for placing the tube therein, wherein the tube guide groove has a cross-sectional shape conforming to the shape of the tube for providing a tube-contacting surface; wherein the cross-sectional shape of the tube-contacting surface defining the tube guide groove is one of an arc-shape that concentrically conforms to the shape of the ball, or a shape that linearly approximates said arc-shape; when a radius of the arc-shape is R, a radius of the ball is r, and a thickness of the tube is T, the following Numerical Expression 1 is satisfied: