Patent ID: 6739373
Filing Date: 2004-05-25
Classification: E06B

Abstract:
A lift control device for a roller shade comprising:a side cover with two sides and having a chamber with an inner surface defined in one side of the side cover; an axle with a center extending outward from the inner surface of the chamber; and multiple inner teeth formed on the inner surface and around the axle; a roller rotatably received in the chamber in the side cover and mounted around the axle, and the roller having an annular body with a diameter and a central hole mounted around the axle and having a first side facing the side cover and a second side; multiple teeth formed on the first side of the annular body and parts of the teeth engaging with parts of the inner teeth on the side cover; and at least one stub extending from the second side of the annular body; a chain retaining wheel rotatably received in the chamber in the side cover and mounted around the roller, and the chain retaining wheel having an annular body with a center; and an eccentric hole defined through the annular body and eccentric to the center of the annular body of the chain retaining wheel to rotatably receive the roller; a chain secured to the chain retaining wheel to rotate the chain retaining wheel; and a follower spool attached to the chain retaining wheel and engaging with the at least one stub on the roller to rotate with the roller, wherein the center of the annular body coincides with the center of the axle on the side cover; the eccentric hole has an inner diameter equal to the diameter of the annular body of the roller so that the roller is eccentric relative to the center of the axle on the side cover; and the central hole in the roller has an inner surface abutting against the axle at a position apart from the parts of the teeth on the roller engaging with the corresponding parts of the inner teeth on the side cover.