Patent ID: 7267333
Filing Date: 2007-09-11
Classification: B65H,F16H

Abstract:
1. A power transmission device comprising: (a) a driving gear having gears over an entire circumferential surface thereof; (b) a first follower gear including an intermittent gear having a toothless portion; (c) a second follower gear having gears over an entire circumferential surface thereof; and (d) a controller for controlling the first follower gear to be engaged with or disengaged from the driving gear, wherein the first follower gear comprises the intermittent gear which is engaged with the driving gear and a whole gear over an entire circumferential surface thereof which is engaged with the second follower gear, and wherein each of the driving gear, the first follower gear comprising the intermittent gear and the whole gear of the first follower gear, and the second follower gear is a helical gear.