Patent ID: 8075439
Filing Date: 2011-12-13
Classification: A47K,E05F,E05Y,F16D,F16H,H02K

Abstract:
1. An automatic opening-closing device comprising: a motor having a shaft, a speed reducer connected to the shaft, a planetary gearbox having a sun gear driven by the speed reducer, and an output axle, and a protection device comprising a driven ring and a driving ring; wherein one end of the output axle is secured to the driven ring and an output shaft of the planetary gearbox is secured to the driving ring, whereby the output shaft drives the output axle to rotate between a first position and a second position via the protection device; wherein the protection device is a friction clutch, the driving ring and the driven ring comprising an inner ring and an outer ring, the outer ring having a wall at one axial end and the inner ring being disposed within the outer ring, the friction clutch having at least one spring disc disposed within the outer ring and sandwiched between an axial end face of the wall of the outer ring and an axial end face of the inner ring, and a circlip holding the inner ring inside the outer ring against the urgings of the spring disc; such that the inner ring and outer ring rotate together unless acted upon by a force greater than a predetermined maximum.