Patent ID: 8820385

Claim:
A control device for a cordless blind with a willful stop, comprising: a force-return mechanism installed inside a housing, the force-return mechanism including a flat spring bevel gear and an elastic element, wherein one end of the elastic element is connected to the flat spring bevel gear to provide a retracting force of the flat spring bevel gear; a shaft connector installed inside the housing, wherein one end of the shaft connector has a transmission bevel gear meshed with a bevel gear of the flat spring bevel gear, and the other end of the shaft connector has a first inserting opening; a braking buffer mechanism installed inside the housing and including a friction ring and an impeding spring, wherein the friction ring is immovably fixed inside the housing with a wear-proof annular inwall and the impeding spring is tightly plugged into the wear-proof annular inwall with an extrusion to prevent the rotation of the transmission bevel gear; and a shell integrated to the housing to form a first chamber and a second chamber, wherein the braking buffer mechanism is accommodated in the first chamber and the flat spring bevel gear and the transmission bevel gear are accommodated in the second chamber, wherein the shaft connector penetrates through the first chamber and the second chamber of the housing until the first inserting opening is exposed from an opening formed by the combination of the housing and the shell; wherein the shaft connector has a trigger and a brake adjacent to the other end of the shaft connector opposing to the transmission bevel gear in a manner that the trigger and the brake of the shaft connector are accommodated in the first chamber; wherein the brake is in contact with the extrusion of the impeding spring with an original friction force formed between the impeding spring and the friction ring when the cordless blind is stopped; wherein the trigger is in contact with the extrusion of the impeding spring to reduce the original friction force formed between the impeding spring and the friction ring when the cordless blind is lifted.