US Patent 7550687 Architecture effectively connecting a rotary switch and a casing

An architecture effectively connecting a rotary switch and a casing comprises: a rotary switch and a casing that is engaged with the rotary switch via a rotary disc of the rotary switch. The casing has multiple snap-fit parts corresponding to snap-fit slots of the rotary disc to form a snap-fit interconnection therebetween. When the casing is rotated, the casing will drive the rotary switch to rotate via the interconnection between the snap-fit parts and the snap-fit slots, and a signal module will output instructions corresponding to the rotation track of the rotary disc. The interconnection between the casing and the rotary disc is implemented with a snap-fit method, and the rotated casing drives the rotary disc to rotate synchronically and create signals. As the casing is engaged with the rotary disc via a snap-fit method, the casing is hard to deviate or loosen. Thus, correct instructions will be exactly output.